Patent Application
20120185115
The invention relates to mobile robotic apparatus in general and particularly to a robotic apparatus that comprises a laser useful to deactivate explosive ordinance.
An unfortunate reality of our latest conflict in the Middle East is the deployment of the IEDs or, Improvised Explosive Devices, used against coalition forces. These devices account for approximately two-thirds of all causalities experienced in the theatre of operations. In response to this growing threat, the Defense Department has deployed EOD or Explosive Ordinance Disposal Robots to combat these threats. Unfortunately even the best EOD Robots require some level of physical inspection in order to assess suspicious packages. This can often leave an operator still guessing as to what exactly is in fact inside. This results in the use of explosive charges in order to absolutely be certain the item is in fact neutralized.
One common strategy is to identify threats, mark them, move around them and subsequently neutralize them. Neutralization strategies range from destroying the threat with explosives, destroying it with another munition (for example, a .50-caliber rifle shot) or physically disarming it. The first two options result in high order/high explosive effects and can only be done when environmental considerations allow. Disarming is the most dangerous to personnel and can also result in high order detonations.
Laser systems can be used for explosive ordnance disposal (EOD). In an article dated Feb. 1, 2003, available at http://www.ausa.org/webpub/DeptAUSANews.nsf/byid/CCRN-6CGM64, there was reported the Zeus laser neutralization system which was developed by Sparta, Inc., Huntsville, Ala., in conjunction with the U.S. Army Space and Missile Defense Command. The system integrates an up-armored Humvee with a 10 kw solid-state laser that has an effective stand-off engagement range of up to 300 meters against unexploded ordnance, surface laid land mines, and improvised explosive devices (IEDs). ZEUS uses a pair of lasers, a joystick-controlled green Nd:YAG laser to designate the target, and an invisible high-power Nd:YAG laser to heat the target until the ordnance or mine explodes. Since the laser is focused on the outer casting of the target, the heat it projects raises, dramatically, the temperature of the explosives within the casing until it is destroyed by internal combustion. This combustion produces a low-level detonation compared with the explosive power found in landmines and unexploded ordnance. The system, crewed by two soldiers—a commander/driver and a laser device operator—provides a safe environment for the troops. Ground targets can be acquired more than two football fields away and, once spotted by the on-board camera that can be linked to a GPS platform, will be destroyed by the laser at a safe distance.
With lasers one can cause outgassing, where the filler or explosive will diffuse itself. Other times, depending on the casement, whether it is plastic or metal, especially metal, it will do low order detonation, or what is called deflagration. Since one can dial the amount of energy that one wants to put into the munition using the laser, one can dial the effect.
A CRS Report for Congress, identified by Order Code RS 22330, and dated Aug. 28, 2007, entitled “Improvised Explosive Devices (IEDs) in Iraq and Afghanistan: Effects and Countermeasures,” which is available online at http://www.fas.org/sgp/crs/weapons/RS22330.pdf, provides the following description of the problems associated with the problems posed by IEDs.
A typical IED terrorist cell consists of six to eight people, including a financier, bomb maker, emplacer, triggerman, spotter, and often a cameraman. Videos of exploding U.S. vehicles and dead Americans are distributed via the Internet to win new supporters.
New designs and technology for explosive devices, such as “passive infrared” electronic sensors are used for triggering roadside bombs. The new sensors are more resistant to electromagnetic countermeasures now employed by U.S. forces. A more lethal IED bomb design called an explosively formed projectile (EFP) is made from a pipe filled with explosives and capped by a specially shaped metal disk. When the explosives detonate, they transform the disk into a jet of molten metal capable of penetrating armor. EFPs reportedly strike with enough power to cause pieces of a targeted vehicle's heavy armor to turn into shrapnel, making them much more deadly than traditional IED weapons. Over time, the insurgents in Iraq have adapted to many U.S. countermeasures, and several DOD officials have stated that protective equipment sometimes seems to be less effective after being deployed for only a few months.
DOD has established the Joint IED Defeat Organization (JIEDDO) to investigate countermeasures to reduce the IED threat. The technologies being evaluated include electronic jammers and pre-detonators, radars, X-ray equipment, robotic explosive ordnance disposal equipment, physical security equipment, and armor for vehicles and personnel.
In the past year, JIEDDO has funded jammers for Marine and Army units, including robots for explosive ordnance disposal teams, Cougar vehicles for route clearance teams, and Guardian, a man-portable jammer for dismounted operations.
Some counter-IED technologies include a stoichiometric diagnostic device, which can decipher chemical signatures of unknown substances through metal or other barriers. Known as the CarBomb Finder model 3C4, it sends out neutrons that cause any substance within a container or vehicle to emit back gamma rays that contain unique signatures from which the chemical formulas are derived. Electronic jamming devices include the IED Countermeasures Equipment (ICE) and the Warlock, both of which use low-power radio frequency energy to block the signals of radio controlled explosives detonators, such as cell phones, satellite phones, and long-range cordless telephones. Other countermeasures include the Joint IED Neutralizer (JIN) and the Neutralizing Improvised Explosive Devices with Radio Frequency (NIRF), which produce a high-frequency field to neutralize IED electronics at a distance. A system now deployed in Iraq, code-named PING, fits inside a Humvee and sends out electromagnetic waves to penetrate the walls of buildings to detect IEDs. Other sensors, such as the Laser-Induced Breakdown Spectroscopy system (LIBS), detect traces of explosives used for IEDs from as far away as 30 meters.
However, the Radio Frequency (RF) spectrum in the Iraq combat theater is largely not managed, and counter-IED radio jammers can sometimes lock onto other U.S. electronic combat systems because of a lack of coordination of spectrum usage. Also, Unmanned Aerial Vehicles (UAVs) can sometimes lose their radio control links due to ground-based radio interference caused by counter-IED jammers once they are far away from their control base. Therefore, DOD is now developing an “Electronic Warfare Coordination Cell” to help sort out problems that can impede friendly operations, or endanger Explosive Ordnance Teams as they disable IEDs on the ground.
Threat data about IEDs is tightly controlled by DOD to avoid giving feedback to the enemy about the effectiveness or ineffectiveness of different IED designs. Also, proprietary rights must be protected for those companies who produce IED countermeasures.
Both self-guided robots and remotely controlled robots are known in the literature. The prior art relating to self-guided robotic devices includes many different kinds of robots, including for example a number of patents issued for robotic lawnmowers. U.S. Pat. No. 4,777,785, issued on Oct. 18, 1988 to Rafaels, describes a method of guiding a robotic lawnmower that relies on pairs of sensors, one of which emits and one of which detects electromagnetic radiation. U.S. Pat. No. 4,887,415, issued on Dec. 19, 1989 to Martin, describes a robotic lawnmower that relies on infrared obstacle detectors to provide guidance signals. U.S. Pat. No. 5,163,273, issued on Nov. 17, 1992 to Wojtkowski et al., describes a robotic lawnmower that relies on a buried wire to provide guidance. U.S. Pat. No. 5,974,347, issued on Oct. 26, 1999 to Nelson, describes a robotic lawnmower that relies on a plurality of radio transmitters to provide guidance signals. U.S. Pat. No. 6,009,358, issued on Dec. 28, 1999 to Angott et al., describes a robotic lawnmower that relies on a plurality of transceivers, one that transmits signals having different propagation velocities, and one that receives the signals. German Patent No. DE3918867, which was published on Oct. 19, 1989, also describes a robotic lawnmower that employs buried iron bars as a guidance system. Friendly Robotics is the assignee of U.S. Pat. Nos. 6,255,793, 6,339,735, 6,417,641, 6,443,509, and 6,493,613, and U.S. Design Patent D451,931, directed to robotic lawnmowers that use proximity sensors to detect predefined boundaries.
The manual cutting of an edge is a variation on the installation of boundaries, paths, buried wires, or transmitters. Some robotic lawn mowers rely on distinguishing the cut height of grass from the uncut, taller grass, and following the edge. One example is described in U.S. Pat. No. 4,133,404, issued Jan. 9, 1979 to Griffin. A manually cut edge or border is simply another predefined boundary or path, one that needs to be “reinstalled” before each occasion when the grass is to be cut.
There is a need for a robotic apparatus such as a device for neutralizing IEDs that can operate autonomously without the necessity to define either a path or a boundary by the placement of transmitters or other indicators, and that can disable such IEDs with minimal danger to personnel.
In one embodiment, the invention features a remotely-controlled robotic apparatus. The remotely-controlled robotic apparatus comprises a robot portion configured to provide mobility and the ability to control the location and orientation of the apparatus in response to at least a first control signal received by the remotely-controlled robotic apparatus from a remote source; a laser portion configured to be aimed at an object of interest and configured to deactivate the object by destroying, damaging or disconnecting at least one of a control apparatus and a power supply from the object of interest in response to at least a second control signal received by the remotely-controlled robotic apparatus from the remote source; and a microprocessor-based local controller configured to communicate bidirectionally with the remote source, the microprocessor-based local controller configured to issue commands to operate the robot portion and the laser portion of the apparatus.
In one embodiment, the object of interest is an IED. In one embodiment, the remotely-controlled robotic apparatus further comprises a camera configured to obtain an image under the control of the microprocessor-based local controller. In one embodiment, the remotely-controlled robotic apparatus further comprises an illumination source configured to illuminate an object of interest under the control of the microprocessor-based local controller. In one embodiment, the first control signal and the second control signal received by the remotely-controlled robotic apparatus are received by a transceiver.
In one embodiment, the laser portion is configured to mark an object of interest with a specific mark. In one embodiment, the specific mark used to mark an object of interest is smaller than 5 millimeters in lateral extent. In one embodiment, the specific mark used to mark an object of interest is smaller than 1 millimeter in lateral extent.
In one embodiment, the remotely-controlled robotic apparatus further comprises a drive system comprising a plurality of independently operable treads, the drive system in electrical communication with the microprocessor-based local controller, the microprocessor-based local controller configured to command the operation of each tread to control at least one of a location and an orientation of the remotely-controlled robotic apparatus; a memory module in electrical communication with the control module, the memory module configured to store and retrieve information; and a locator module in electrical communication with the microprocessor-based local controller, the locator module configured to discern at least one of a position and an orientation of the remotely-controlled robotic apparatus.
In another aspect, the invention relates to a remote controller configured to control the remotely-controlled robotic apparatus. The remote controller comprises at least one input configured to accept an instruction from an operator, the instruction to be transmitted to the remotely-controlled robotic apparatus; an output configured to provide information about the remotely-controlled robotic apparatus to the operator; a transceiver configured to transmit control signals to the remotely-controlled robotic apparatus and to receive data signals from the remotely-controlled robotic apparatus; and a microprocessor-based control module configured to manipulate the instructions from the operator to provide control signals to be transmitted to the remotely-controlled robotic apparatus, and configured to manipulate the data signals from the remotely-controlled robotic apparatus to provide information about the remotely-controlled robotic apparatus to the operator.
The foregoing and other objects, aspects, features, and advantages of the invention will become more apparent from the following description and from the claims.
The objects and features of the invention can be better understood with reference to the drawings described below, and the claims. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the drawings, like numerals are used to indicate like parts throughout the various views.
The invention provides in one embodiment a remotely operated Explosive Ordnance Disposal (EOD) robot with an onboard non-combustible offensive weapon system that disables explosive ordinance by deactivating or disconnecting a control mechanism of the device, without necessarily detonating or otherwise causing the explosive device to explode. An example of such a robot is shown in
In one embodiment, the robot is controlled wirelessly.
Current EOD robots are quite expensive (commonly costing in the range of $125,000 to $250,000 each) and therefore are limited in the theater of combat operations. One type of EOD robot comprises a manipulator arm for exploratory work on suspected IEDs. These systems are quite bulky and are cumbersome to operate. Often their efforts do not offer enough information on the state of a suspect package due to their limited motion by grippers that they deploy. The EOD robots of the present invention can be made much more affordable and with better capabilities.
In one embodiment, an operator (also referred to as a “user”) will steer the robot via an operator console 1330 having a control interface 1465, such as a video display comprising a graphical user interface (or GUI) in the case of a computerized control system, where both command data as well as visual information are both controlled and observed. The operator can control the robot 1320 using one or more hand controls, such as a joystick 1470. Other suitable controls can be other manually operated controls such as push buttons, keyboards, slider controls, an alternative computer pointing device such as a mouse, or inputs such as touch screens. In more advanced systems, voice commands can be used to control the robot and its components. Once near the object of interest, a non-intrusive visual inspection will occur. If this inspection does not reveal enough information to clearly determine that the package is safe, the operator has the option to incinerate the control system of the object. This can be achieved by the EOD robot when it is positioned at a distance up to several meters away from the object. The operator can be located at a distance of many meters from the object of interest, including any distance that can be covered by the wireless control system. In principle, the operator could be anywhere on Earth. The operator has the choice to either set afire the object to burn its coverings away for inspection and or to incinerate the object through repeated pulses. In many instances, an IED is controlled using an electrical or electronic control, such as a wireless control (such as a cellular telephone or other wireless remote control such as a wireless garage door opener, a wireless doorbell, a television remote control, an infra-red remote control or similar wirelessly operated control) that is connected to the explosive device and that requires a battery for power. In such instances, it is preferred to destroy either or both of the battery that provides power to the wireless control, and the wireless control itself. Alternatively, one can destroy the wiring between the control and the explosive device, thereby preventing an operator from exploding the device even if a signal to cause an explosion is transmitted.
Sometimes pipe bombs and other IEDs are disguised by being hidden in or underneath debris. By removing the debris, inspection of its contents can become easier. In some embodiments, the incineration of the debris exterior alone could cause the IED control or battery to malfunction and disarm. For example, a fire set by the laser could burn away vital electrical wiring and/or circuitry. The laser is controlled by the operator with the aid of the camera system, offering the user a safe view of the object of interest.
When a suspicious item thought to be an IED is detected along a typical roadside in Iraq, the road can be shut down for up to 4 hours. In order to reduce the required time to inspect and or dismantle an IED, a robot capable of providing both operations is provided. This robot can surgically destroy power sources and/or triggering devices to render an IED harmless.
In another application, the laser can be operated to identify an opponent with a specific mark. In one embodiment, a laser lens is provided that is capable of creating a specific mark or insignia on the skin or clothing. The specific mark or insignia can comprise information useful to identify a person of interest, such as a graphic image or pattern specific to the laser emitting the infra-red radiation, and if desired, information such as a time and date. In most cases when troops are engaged from a distance by opponents such as insurgents, an insurgent may hide among or blend into civilians around him making it difficult to identify a specific individual who fired a weapon or performed some other hostile act. In some situations, firing a deadly weapon at an insurgent is likely to cause significant collateral damage and might be better avoided. However, in such a case troops most often detain multiple individuals in an effort to identify the one person (or few people) for whom they are looking. In order to reduce valuable time in searching for an individual and to avoid detaining persons who are not implicated in a hostile act, particular individuals can be designated by being marked (or by marking their clothing) with a visible pattern or image. Troops searching for such an individual would look for the marking which would identify the person or persons who engaged them. The graphic can be produced by passing a laser beam through a shadow mask, and information such as a time and date can be applied by providing an addressable partially transparent display in the path of the laser beam. As may be required, a projection lens system can be provided to project the image at a distance. In various embodiments, the size of the designator pattern or image can be controlled by the lens to be of a small size, for example, smaller than 5 millimeters in lateral extent, or smaller than 1 millimeter in lateral extent, so as to be relatively unobtrusive. In some embodiments, the image could be constructed to have reflective properties under a specific wavelength or wavelengths (e.g., the pattern could be in the form of a periodic array or grating), making the mark easier to recognize and to authenticate.
In another embodiment, a robot having the learning and self-guiding properties described hereinbelow can be used as an apparatus configured to patrol a defined path. As the robot patrols, it can determine its location and heading to orientation, and it can observe its surroundings using the camera provided. The camera images can be recorded with information about the location and orientation of the robotic apparatus. If an object of interest is observed, the laser can be operated to identify the object of interest with a specific mark. On a subsequent patrol of the same path, the recorded camera images from a previous patrol can be compared with the live images taken at the corresponding location and orientation, and changes in the surroundings can be observed and identified. Specific marked objects of interest can be examined to see if the mark applied on a previous patrol is present, so as to confirm that the object is the same object that was previously observed, or to indicate that the object is a different object (e.g., one lacking the mark that was applied at an earlier time). Suitable responses can then be taken as appropriate.
In a further embodiment, one or more additional “sacrificial” robots are provided. A sacrificial robot is also controlled by the operator console 1330. The sacrificial robot can be used to deliberately set off trip wires, motion sensors, or pressure sensors, without exposing a robot comprising a laser to such dangers. In one mode of operation, the sacrificial robot approaches an object to be deactivated, or simply patrols a path to be traversed. If the presence of the sacrificial robot does not set off an object to be deactivated, the EOD robot 1310 can then approach and deactivate the IED. This allows exploratory investigation of suspicious packages without the need to expose the more expensive LaserBot to potential damage or destruction.
The sacrificial robots can in some embodiments present a similar appearance as that of the robot 1310. In such instances, the laser 1320 may be removed and substituted with an object that simulates the appearance of the laser 1320, but that is much less expensive to build. One utility provided by a sacrificial robot would be to confuse an opponent, who then would not know for sure which of several apparently identical robots carried a laser. In order to destroy a robot comprising a laser, the opponent would have to attack all such robots to assure that the one or more having a laser was being attacked. In some embodiments, the substitute for the laser could be constructed of a heavy material, for example solid metal, or a metal or plastic box filled with a dense material, so that the weight of the “sacrificial” robot is higher than the weight of the robot having the laser 1320 mounted thereon. The sacrificial robot can be driven to a location of interest in a manner similar to a robot 1310 having a laser, or can be delivered to a location by a transport trailer attached to the robot 1310. An operator could drive the sacrificial robot off the transportation trailer and later return the surviving sacrificial robot back to the trailer.
The CO2 laser makes for a light weight readily transportable device capable of temperatures that could easily cut metals. One example of a suitable laser is the LABURN2 Laser System, a 10 to 20 Watt TEM00 CO2 10 Micron Laser System, available from Information Unlimited, PO Box 716, Amherst, N.H. 03031 (http://www.amazing1.com).
The design of a CO2 laser is relatively simple with heat dissipation equipment comprising some of the heaviest components. Compressed CO2 gas is provided in a lightweight tube. When an electrical discharge is passed through the gas laser medium, the result is brilliant infra-red light or illumination, as is well known in the laser arts. The resulting light beam is highly monochromatic and coherent. The infra-red laser can be used to heat a target of interest.
In one embodiment, power to operate the laser is derived from a bank of 12 volt deep cell rechargeable batteries. These batteries are specifically designed for extensive current draw and provided a continuous flow of power to a 400 watt inverter. In one embodiment that was constructed, a 115 Volt AC class IV laser was provided with power from an inverter connected to batteries wired in parallel. The laser was capable of continuous or burst firing for up to 1 hour on a 12 volt, 18 ampere battery supply.
In one embodiment, a trailer 1810 is provided for towing behind the robot 1310, as shown in
CO2 lasers are available with ratings in the range of tens of watts to as much as 100 KW or more. Our preliminary designs suggest a rating of 500 watts, (Class IV Laser), would provide more than enough power while still being cost effective. A rating of 500 watts represents 25 times more power than our test model, which deliberately had no focal lenses. This power should provide the ability to incinerate any electrical components within seconds of initiation. Power requirements depend upon visual clarity as distances could reduce an operator's ability to exactly aim the beam on precise locations. In some embodiments<a variable focal length lens (such as a telephoto lens) is employed in order to magnify target views. Because CO2 lasers emit radiation in the infra-red portion of the marker visible to an operator in order to select a target for incineration. A 500 watt LaserBot can easily set a fire up to several hundred meters away. In some embodiments, once a fire has been set, the operator can approach the device in order to begin surgical incineration if required. In other embodiments, the LaserBot can approach the IED at relatively close range, and deliberate heating of specific components, such as a battery or a control mechanism can be performed with reduced risk that the IED will be caused to detonate. The operating range of the laser can depend upon a variety of factors such as electrical wattage and focal lengths of lenses. The LaserBot provides an improvement in Explosive Ordinance Disposal (EOD) systems and methods.
There are important benefits to using a robot such as the LaserBot. Because there is no necessity for a human to be in proximity to the device thought to be an IED, the danger to human operators is minimized. As will be discussed hereinbelow, because the LaserBot in some embodiments can be taught to traverse a route, and can identify its location and orientation, the camera can be used to record a real time video of the terrain and surroundings that the LaserBot traverses, so that the environment observed on repeated traversals can be compared (e.g., comparison of a recorded video taken from a specific location and orientation can be compared with the real time signal from the same location and orientation on a subsequent traversal) to assist in identifying objects that are “new” or that have been moved, so as to identify possible IEDs or suspicious objects in or under which IEDs might be hidden.
In addition, there are numerous benefits to disarming an IED without causing it to explode. For one thing, deactivating an IED without causing an explosion eliminates the potential for harm to intended and unintended victims (e.g., reduced danger to military or police personnel, as well as to innocent bystanders and to property). The addition of motion sensors by insurgents makes it virtually impossible for standard EOD robots to be deployed for visual inspection. By deactivating a device while preventing it from exploding, intelligence such as its design and possible maker can be obtained. The LaserBot can initiate an attack from a distance to verify if motion sensors are being deployed. If after incinerating parts of a suspicious package the item still has not gone off, the LaserBot can approach the device for further evaluation and/or destruction of the device. This surgical ability to eliminate at will individual components, such as a control mechanism, a battery, or a wire, is unmatched with regard to current EOD robots.
An operator station, which can be a portable base station, is provided for controlling the mobile robotic platform and its components. The operator station comprises a visual screen configured to provide more than one camera view, one or more command actuators (such as joysticks, keyboards, or other user operable controls) for motor control functions, a video receiver module and a data transceiver module in electrical communication with the visual screen, one or more command actuators in electrical communication with an RF transmitter module that can issue command wirelessly to the LaserBot. Sufficient actuators are provided to control the operation of the locomotion, camera, and laser functions of the LaserBot.
The LaserBot comprises a remotely operated platform configured to receive commands sent by a wireless transmitter, including a receiver in electrical communication with a motor control module, the motor control module configured to control twin independently operated tracks, a receiver module configured to control tool functions, the tool functions configured to perform functions such as audio and video transmissions, a visual designator or pointer, and a laser tool. There is provided a control module in electrical communication with receiver module, the control module configured to operate the laser tool. The laser in one embodiment is a CO2 laser operating in the infra-red. The laser tool is configured to perform the cutting and incineration of foreign materials. The operator station is configured to receive visual information from a camera n the LaserBot in electrical communication with a video transmitter module. A data transceiver module on the LaserBot is configured to send analog and digital data to and to receive analog and digital data from the operator station. Data generated on the LaserBot can include sensor data from sensors onboard the LaserBot. The onboard sensors can include sensors that generate signals representative of position, orientation, battery levels, radiated power, temperature, sound, light, biological measurements, and smoke or other atmospheric conditions.
In the present description and claims, the term “locator module” is intended to denote any of a compass module based on an electronic compass, a module that determines location and/or orientation using one or more detectors suitably configured to receive and to decode “environmental signals” as that term is used herein, and a module that allows he robotic apparatus to determine its location and/or orientation by transmitting a signal from the robot to one or more stations and receiving a responsive signal comprising the location and/or orientation information at the robot according to principles described hereinbelow.
Robotic apparatus built and operated according to principles of the invention provide systems and methods for operating in an autonomous manner under the control of a programmed computer operating in communication with a digital compass configured to discern an orientation of the robotic apparatus. In one embodiment, the digital compass senses the magnetic field of the planet Earth. The digital compass can be implemented as a device built on a circuit board, which can discriminate two or three axial directions. Orientation readings provided by the compass are used during the operation of the robotic apparatus. An electronic digital compass suitable for use with the present invention is described in U.S. Pat. No. 4,851,775, issued on Jul. 25, 1989 to Kim et al., and assigned to Precision Navigation, Inc. of Menlo Park, Calif., the entire disclosure of which is expressly incorporated herein by reference in its entirety. Electronic digital compasses of this type are available commercially from Precision Navigation, Inc., for example as the Vector 2X electronic digital compass. Technical application notes for the Vector 2X electronic digital compass are available online at http://www.precisionnay.com/legacy/technical-information/pdf/veetor-2x.pdf.
In alternative embodiments, the electronic digital compass can be replaced with other apparatus for detecting the location of the robotic apparatus relative to a signal that is not provided for use with a specific area of interest that the robotic apparatus will traverse, but rather is provided for other purposes, but can be adapted to the use of the robot. A first example includes the detection of signals from a plurality of satellites in orbit about the planet Earth, such as Global Positioning System (GPS) signals with a GPS detector. Another example is the detection of signals from a plurality of cellular telephone communication towers erected at known locations using cellular telephone technology, and locating a robot by triangulation. A still further example is the detection of signals from a plurality of radio or television broadcast antennas or towers or broadcast satellites using appropriate detector technology, and locating the robot by suitable calculation using the known location of the signal source. In each such example, the presence of the GPS satellites and their signals, the presence of cellular telephone communication towers and the signals associated with them, or the presence of radio or television broadcast antennas or towers or broadcast satellites and the signals associated with them, are all provided independently of the robot or its purposes, and may be considered “environmental” signals that occur in the environment without any action on the part of the robot or its operator, in analogy to the magnetic signals present as a consequence of the magnetic properties of the planet Earth. Thus, a robot having one or more detectors suitably configured to receive and to decode any of such “environmental signals” can be programmed to operate in a manner similar to a robot having an electronic digital compass. For the purposes of this discussion, the term “environmental signal” will be understood generally as any artificial signal that is provided for purposes other than for the demarcation of a particular area or path of interest, and that is exploited by a robotic apparatus for traversing an area or a path of interest. The “environmental signals” are detected by a respective one of an environmental signal detector module, such as a GPS detector, a cellular telephone signal detector, or a radio or television signal detector. In using such “environmental signals,” in some embodiments a plurality of locations of the robot are determined as it moves, and a vector heading or orientation is derived from two or more deduced locations.
Yet another example of using an “environmental signal” involves a two-part communication. In one embodiment, the robotic apparatus comprises a transmitter and a receiver. The transmitter can in various embodiments be the transmitter found in a cellular telephone, a transmitter such as portable radio device such as a citizen's band radio, or a radio frequency transmitter such as is found in RF-ID technology. The receiver is any receiver that can receive a signal comprising location information. Each robotic apparatus is assigned a unique identification code or number, such as is found in devices of the types mentioned in the previous sentence. When in operation, a robotic apparatus periodically broadcasts at least its unique identification code or number as a message to one or more stations that can identify the source of the message and to locate that source, for example, in a geographical manner. The robotic apparatus can optionally include a “time stamp” or an ordinal value in each message so that a particular message can be identified in a sequence of messages. The stations receive the message or messages, determine the location of the transmitter, and send back to the robotic apparatus a message that including the deduced location of the robotic apparatus. The robotic apparatus uses the location information in the same way it would use location information such as it would deduce using the electronic digital compass described hereinabove. The location information can also be used to calculate a direction of motion by comparing successive locations vectorially.
One method of locating the source of the message is triangulation using direction finding. Another method of locating the source of the message is using “time of flight” with multiple receiver stations. Each receiver station identifies the time of receipt of a particular message. In the event that the robotic apparatus and all of the receiver stations have internal clocks that are synchronized, the distance of the robotic apparatus from each receiver station can be computed directly from the time delay of the transmitted message and the known speed of propagation of the signal. The speed of signal propagation can be calibrated by sending a signal between two receiver stations spaced a known distance apart (e.g., from one cellular telephone cell tower to another tower). The clocks can be periodically reset using one of the clocks as a master, so as to maintain synchrony.
In an embodiment in which a set of synchronized clocks does not exist, or if a time signal is not used, the location of the robotic apparatus can be identified as follows. For any two receiver stations, the difference in time that the same signal is received at two different receiver stations indicates a difference in distance of the robotic apparatus from the two receive stations. In other words, simultaneous reception (e.g., time difference equals zero) indicates that the robotic apparatus is positioned along a line perpendicular to the line connecting the two receiver stations, the perpendicular line intersecting the line connecting the two receiver stations at its midpoint. As the time difference increases, the locus of the possible positions of the robotic apparatus becomes a curvilinear line offset from the aforementioned perpendicular line by a distance x along the line connecting the two receiver stations such that the difference in transit time of the signal is that observed, and meeting the perpendicular line at substantially infinite distance in either direction along the perpendicular line (i.e., at those points where the difference is negligible relative to the absolute distance of the robotic apparatus from either receiver station). By knowing the transit time for a signal between the two locations of the receiver stations, which can be measured, the magnitude of the distance x can be estimated. The precision of measurement of the difference in time of flight of the signal determines the precision of the measurement of the distance x. By measuring a sufficient number of such pairs of time of flight differences, such as three pairs, a location of the robotic apparatus can be identified unambiguously in two dimensions, i.e., on the surface of the Earth, neglecting curvature of the Earth and changes in altitude of different locations. Measuring more that three pairs will give better resolution and added confidence in the accuracy of a location determination. In an alternative embodiment, the receiver stations send the raw data that they receive back to the robotic apparatus, and the computation of a location is performed at the robotic apparatus. In still other embodiments, the signals transmitted by the robotic apparatus and/or the receiver stations are communicated using any convenient electromagnetic radiation, including any of infrared, visible and ultraviolet light, and radio waves in the KiloHertz to the GigaHertz frequency range.
Present day systems, such as Enhanced 911 are being deployed by multiple telephone companies to locate cellular telephones over long distances (miles) to within 50 to 100 meters, as is described in an article entitled “They Know Where You Are,” that appeared in the July 2003 issue of IEEE Spectrum magazine at pages 20-25. The same article indicates that RF-ID tags can locate objects over distances of meters. Neither of these technologies as disclosed in the article is sufficient for the distances required while providing the accuracy of positioning required in the present invention.
Another embodiment discussed in the IEEE Spectrum article is ultrawideband transmission, which is capable of locating an object over a distance of approximately hundred of meters to perhaps a kilometer (0.62 mile) with an accuracy of approximately one-half meter (approximately 20 inches) to ten meters (approximately 32 feet). Accuracy of one centimeter at distances of one kilometer can be foreseen, but is not yet available. In addition, the apparatus needed for such transmissions is expensive at present, costing about $2000 per base station and about $25 per mobile transponder.
In one embodiment, the invention finds use as a robotic apparatus that can traverse an area of interest autonomously. In one exemplary embodiment, the robotic apparatus is a lawn mowing machine.
In one embodiment, a robotic apparatus has two substantially similar electric motors located on opposite sides of the apparatus, each connected to the frame or chassis with bolts or the like. Speed reduction gears reduce the output rotational speed of each motor. As will be described, the rotational speed and direction of each motor is individually adjustable. The two motors are configured to be controlled individually. A drive system on each side of the robotic apparatus, such as a chain drive connected to a sprocket on a wheel assembly, provides power from each motor to a corresponding wheel. A rubber track is provided on each of the two sides of the chassis. Each track is fastened to one or more wheels, one of which is the wheel driven by the motor, which track moves the robotic apparatus as required.
In one embodiment, a robotic apparatus intended for use as a lawn mower is operated primarily through the use of a gasoline-powered engine. In one embodiment, the apparatus derives its electrical energy needs by employing an alternator driven by the gasoline-powered engine. The gasoline-powered engine also drives a rotating vertical shaft that supports a cutting blade. The blade is connected to the motor by way of a clutch mechanism, so that the motor can remain in operation while the cutting blade can be disengaged. A portion of the AC current generated by the alternator is then converted to DC power to provide for the energy needs of the remaining circuits.
In one embodiment, a machine of the invention is capable of recording directives and digital compass readings while in operation for later playback, can play back recorded instructions, and can operate autonomously according to the recorded instructions. The directives can be provided from an external source. In one exemplary embodiment, a person uses a hand held device such as a cell phone to issue commands that include directives by pressing buttons on the cell phone. For convenience of exposition, a machine with this recording capability will be called a master. In some embodiments, a record and playback device can be remote from the master robotic apparatus and bi-directional communication between the master robotic apparatus and the record and playback device can occur by short-range radio, for example using the 802.11 protocol. In another embodiment, a machine of the invention lacks the feature of recording instructions, but can play back pre-recorded instructions, and can operate autonomously according to the pre-recorded instructions. For convenience of exposition, such a machine will be referred to as a slave. In some embodiments, a slave machine may also lack the feature of receiving directives from an external source, such as a remote control, but instead operates based on recorded information and a start command or the like issued by manipulation of a control, such as a key or a button on the apparatus. In some embodiments, a slave machine can employ a playback device that would be unsuitable for a master machine (i.e., a device lacking recording capability but having playback capability), such as a CD-ROM player, a magnetic tape player, or the like. Such playback-only devices are useful because they have fewer parts (i.e., less that can fail and require repair), and they may be less costly to acquire and use. In some embodiments, a playback device can be remote from the slave robotic apparatus and bi-directional communication between the slave robotic apparatus and the playback device can occur by short-range radio, for example using the 802.11 protocol.
A machine according to the invention, which in one embodiment is powered by a gasoline engine, and in other embodiments is powered electrically, provides mobility through two independently operated electric motors that power treads, which can be rubber tracks. The invention also provides a computer program recorded on a machine-readable medium that operates on a computer, which can be a commercially available microprocessor. One or more programmed computers provide the ability to control the behavior, including guiding a course of motion of the robotic apparatus, and controlling the use of tools that are attached to the robotic apparatus.
Because both master and slave machines according to the invention use the Earth's magnetic field as a reference, there is no requirement for the installation of any artificial objects such as transmitters or barriers to control the motion or behavior of the programmable robotic apparatus when it is operating autonomously. The magnetic field of the planet Earth is a natural phenomenon that does not require the intervention of a human for its presence. When a command or commands recorded on a machine-readable medium are provided to the apparatus, the apparatus can operate autonomously and can take corrective action when it senses that it has deviated from the expected operational behavior.
Turning to
In the embodiment of
Turning to
The computer program also includes other modules that perform specific functions for the operation of a robotic apparatus. These modules comprise a supervisory module that controls the autonomous operation of a programmable robotic apparatus and that, as required, receives information recorded on a machine-readable medium, and a computation module that computes an error signal based at least in part on orientation information from the compass module and information recorded on the machine-readable medium. The program in some embodiments further comprises an instruction receiver module that receives directives from an external source regarding operation of the programmable robotic apparatus. The program in other embodiments further comprises an error correction module that, in the event that the error signal exceeds a predetermined value, computes an error correction to be provided as a corrective action command to the programmable robotic apparatus.
As indicated in the embodiment shown in
As depicted in
The compass module 110 and the computers 112, 114 are used to measure the orientation of the compass module 110 (and thereby the orientation of the robotic apparatus to which it is mechanically attached) relative to the magnetic field of the planet Earth. The compass module can be oriented with regard to the robotic apparatus by attaching the compass module 110 to the robotic apparatus, and aligning one of its magnetic coils along a desired direction (such as directly forward) and aligning another of its magnetic coils in a perpendicular orientation to the desired direction so as to define a plane that is substantially parallel with respect to a plane upon which the robotic apparatus rests when the compass module is attached.
The compass module 110 provides electrical signals that can be decoded to derive a magnetic compass heading in increments of one degree, ranging from zero degrees to 359 degrees. For the purpose of controlling the robotic apparatus, an angular correction of one degree or less is sufficient for acceptable operation. In order to observe a change in direction, it is sufficient to observe the change of the least significant digit (or units digit) value of the decoded heading. For example, a change in direction from 72 degrees to either 73 degrees or 71 degrees involves observing the change of the least significant digit value “2” to either “3” or “1.” Therefore, decoding signals from the compass 110 so that the least significant digit (i.e., ranging from 0 through 9) is discriminated provides enough signal to deduce that an error has occurred and that a correction is needed. For appreciable changes in direction, for example in excess of 9 degrees, a counter is implemented to tally the successive changes of one degree so as to have available a new heading relative to a previous heading. One can also calibrate the compass to obtain a “true” magnetic heading if that is necessary. The calibration process is explained in U.S. Pat. No. 4,851,775, previously incorporated herein by reference.
Turning to
When the robotic apparatus is in “playback” mode, the relays 126 are respectively connected from their normally open contacts to circuitry that decodes the value of the least significant digit (from “0” to “9”) that is being asserted in response to the signal from the compass module 110. The circuitry that decodes the least significant digit value is shown in the embodiment of
When the robotic apparatus is in “playback” mode, the memory module 134 “plays back” its information, or otherwise makes the information recorded thereon available for use. The information, including DTMF signals corresponding to previously recorded least significant digit information, is made available to a plurality of DTMF decoders 138. In the embodiment of
The two sets of signals represent the least significant digit available in “playback” mode, one from the compass module 110, and one from the memory module 134. The two representations of the least significant digit are then compared. The comparison circuitry of the embodiment shown in
In the embodiment of
A “slave” apparatus, as indicated above may lack the remote input device 102, and may comprise a memory module, 104, 134 that employs only pre-recorded media, and that is not capable of recording new information.
The circuit of
The covering shroud comprises a fiberglass body hinged at one end for internal access. Air intakes that provide air to the combustion engine are located on either side of the shroud. The intakes also provide air circulation to cool operating circuits.
A proximity sensor bar detects objects and sends a signal to alarm circuits. A suitable proximity sensor can be constructed using the touch switch kit available from Ramsey Electronics, Inc., 793 Canning Parkway, Victor, N.Y. 14564. The company has a website http://www.ramseyelectronics.com. Information about the touch switch can be found at http://www.ramseyelectronics.com/cgi-bin/commerce.exe?preadd=action&key=TS1.
A variable resistor 312 is connected between voltage references 306 and 308. The variable voltage terminal 314 of variable resistor 312 is connected to the positive input terminal 324 of op amp 320. Reference voltages 306 and 308 also power op amp 320. Op amp 320 provides an output signal at an output terminal 326 thereof. When operated “open loop” as depicted in
At box 610, there is denoted a device that records information, including the directives from box 608, and the readings of orientation and headings. This will also be understood to denote a module that controls the recording of information on a machine-readable medium for recovery and use at a later time. At box 612, there is denoted a storage step, which is the step of recording the directives and compass readings (in raw and/or in decoded format) on a recordable machine-readable medium, as described hereinabove.
At box 614, signals including directives and compass readings are decoded as necessary, and are provided to switches that control aspects of the operation of the robotic apparatus. At box 616, the switches (in some embodiments, relays) are activated. At box 618, the robotic apparatus is activated by way of driving motors and the like.
At box 706, the heading readings are compared with information, such as information recorded in prior operation of a master robotic apparatus. This information is made available by way of a machine-readable medium in a storage device, as denoted by box 710. At box 712, the stored information is decoded as needed, and is supplied both to the comparison circuit at box 706, and to switches, such as relays, as indicated at box 714 to operate the apparatus. Thus, box 706 will be understood to denote also a computation module that computes an error signal based at least in part on orientation information from the compass module and information recorded on the machine-readable medium. Box 706 can compute whether there has been an error in the operation of the robotic apparatus 10, by comparing the actual orientation signals and the expected (i.e., previously recorded) orientation signals and directives to look for discrepancies. Box 706 will also be understood to denote an error correction module that, in the event that the error signal exceeds a predetermined value, computes an error correction to be provided as a corrective action command to the programmable robotic apparatus. Box 706 can thus send corrective information to box 720.
At box 720, there is denoted a device that issues commands including correction signals to control the robotic apparatus 10 to take corrective actions. At box 714, signals including operational signals and corrective signals, as required, are provided to switches such as relays that control aspects of the operation of the robotic apparatus. At box 718, the switches (in some embodiments, relays) are activated. At box 718, the robotic apparatus is activated by way of driving motors and the like. The computers that control both master robotic apparatus and slave robotic apparatus include a supervisory module that controls the autonomous operation of a programmable robotic apparatus and that, as required, receives information recorded on a machine-readable medium. When the robotic apparatus has completed its programmed activities, it is turned off, either by an explicit instruction in the computer program, or by the intervention of the user.
In an exemplary embodiment, the robotic apparatus is a modified 20″ mowing chassis containing twin electric motors adjacent from one another providing mobility. Each motor is bolted to the frame with sliding mounting brackets to aid in chain tension. From each of the motors, reduction gears are connected to chain assembly, which transfers power down to a sprocket mounted drive wheel. These rotations are counted as electrical pulses and stored for later distance measurements. Maintaining distances ensures the machine does not wander without detection. Rubber tracks are there powered to provide for smooth mobility over diverse terrain. Tension is applied to the tracks with the aid of tension bars, which contain adjustable springs delivered by stainless steel wheels. By applying pressure on the bars in the opposite direction, tension is removed momentarily from the belt thereby allowing for replacement.
In the exemplary embodiment, power is generated by the use of an alternator from which it derives its power by the rotating vertical shaft controlled by a gasoline engine. The AC generated by the alternator is then converted to DC with the aid of a conversion circuit. The electricity is then sent to a central panel where it sources out its DC power to the remaining circuits. A battery stores the remainder of unused electricity for later recall.
In this exemplary embodiment, the vertical shaft powered by the gasoline engine is monitored for strain or an increase in load by a current monitoring circuit. As a load increases, current follows in direct proportion. This detection serves as a monitor for cutting tall grass and prevents the engine form stalling out under duress. Should the current increase sufficiently enough to be detected, an additional circuit will be employed to slow the forward progress and if necessary, stop and reverse before continuing.
In this exemplary embodiment, each drive motor is controlled by a variable speed limiting circuit, which determines their revolutions per minute. Resistance added within this circuit reduces the amount of current fed to the motors, ultimately slowing revolutions for slight directional tuning. Each circuit also has the ability through relays, to switch rotational directions for forward and reverse commands.
In one exemplary embodiment, to begin programming the system, a user designates a starting location. Once an area has been selected, four hollow spikes or tubes are then introduced into the earth to be made flush with the surface. This is achieved by applying slight pressure with ones foot in order to set the spikes. In areas where the earth's density is greater than tapping with the aid of a hammer may be used. A set of guides allow for an accurate placement, as they need to be aligned with the machine. Once the hollow spikes or tubes are made flush, the machine is then placed over the configuration and aligned with placement rods. A rod is placed in each of the four corners of the chassis, allowing for an accurate initial alignment. A consistent starting location is useful to the machines playback operation.
In one exemplary embodiment, a joystick is used to control four commands during programming, forward, left, right, and reverse. Each command is selected by positioning the controller in the four directions. In other embodiments, a hand held transmitting device, such as a cellular telephone, can be used to provide commands. The command generates a unique frequency corresponding with each command. The data is then entered into a recording device through a microphone input and is stored on magnetic tape. Data is simultaneously fed out through the output of the tape player into a series of frequency decoders. These decoders look for unique signatures responsible for controlling the drive motors. This gives immediate feedback to the programmer by viewing the movement behavior of the machine.
A digital compass module, the Vector2x, will enhance the programming data by providing raw measurements to correspond with command inputs. The compass is read by a stamp circuit, which provides for a numeric output. The data is then fed to an adjoining stamp circuit where it is broken into ten possible combinations. Each is represented with a light emitting diode that signals its presence by illuminating. The illumination is detected by light sensitive circuits, which then activate specific relays. These relay control frequency encoders that generate a signal to represent each of the ten possible data outputs. The signals are then fed through a microphone input into a magnetic tape recorder for storage.
In one exemplary embodiment, the programmer overlaps the cutting of the grass by ⅓ the width of the lawn mower. This safeguards any slight changes throughout the entire playback procedures and offers a margin of error.
In the exemplary embodiment described, upon playback, the digital compass serves as a live reading from which recorded data is then compared to. There unique frequencies are detected and their corresponding relays are activated. The electrical signals provided from the decoders are sent to two processors for comparison to those provided from the compass. The two sets of signals representing compass readings are then compared for analysis. This step determines whether the machine is in one of three possible states. They include 1 degree right, 1 degree left and or, center. Of these three states, only the first two signify a need for correction. The processors indicate the status of the three states and output a corresponding signal by activating a light emitting diode.
In the exemplary embodiment, when the diode representing left is activated, a light sensitive circuit senses its presence and triggers a relay. This relay sends a signal to the right side drive motor control where, it increases electrical resistance thereby slowing the motor in direct proportion. When the correction is complete, electrical resistance in the motor controls is returned back to its normal state. This allows the machine to correct its heading slightly to the right, returning back onto its intended course while in forward motion.
In the exemplary embodiment, when the center position is activated, there are no commands being sent to the drive motor control's as there in no correction needed. The diode representing the center position is primarily used to allow a user to calibrate the system.
In the exemplary embodiment, when the diode representing right is activated, a light sensitive circuit senses its presence and triggers a relay. This relay sends a signal to the left side drive motor control where, it increases electrical resistance thereby slowing the motor in direct proportion. When the correction is complete, electrical resistance in the motor controls is returned to its normal state. This allows the machine to correct its heading slightly to the left, returning back onto its intended course while in forward motion.
In one embodiment, each electrical circuit and/or device that can generate electrical fields or that can be affected by electrical fields, can be enclosed, or “wrapped” with a grounded shield mesh (i.e., a Faraday cage) to prevent interference between components.
In another embodiment, for example for use in a “surveillance” mode or “night watchman” mode of operation, the robotic apparatus can have a plurality of sets of instructions pre-recorded, each set of instructions corresponding to one of a plurality of paths traversing an area of interest. One of the pre-recorded sets of instructions can be selected for use in any particular traverse of the area of interest, so that the robotic apparatus behaves in a manner that is not predictable with certainty by a disinterested observer. For example, the selection of a particular set of instructions can be based on a random number generator that can be programmed as a random number generator module in the computer program recorded on a machine-readable medium. The selection can in different embodiments be made by the robotic apparatus itself, or by an external actor, such as a user, or a computer program under the control of a user. The robotic apparatus can use tools such as an electronic camera, a video camera, a radio, a chemical sensor, a biological sensor and the like to detect and to report a condition that deviates from a pre-defined base condition.
The programmable robotic apparatus is configured to receive “environmental signals” of terrestrial origin, which are understood generally as any artificial signal that is provided for purposes other than for the demarcation of a particular area or path of interest, and that is exploited by a robotic apparatus for traversing an area or a path of interest. This system relies principally upon terrestrial signals such as radio, cellular telephone and television broadcast signals that provide the synchronization required for positional triangulation. The “environmental signals” are detected by a respective environmental signal detector module, such as a cellular telephone signal detector, radio signal detector, and a television signal detector.
Unlike GPS which relies principally upon non-terrestrial signals transmitted from distances of thousands of miles from satellites in space (e.g., in earth orbit), the origin of terrestrial signals is expected to in general be much closer to the programmable robotic apparatus (e.g., typically within tens of miles or less). This close proximity greatly improves the reliability and reduces environmental signal deterioration. An array of environmental sensors can provide information about environmental weather conditions, such as moisture, that could otherwise distort signal reliability through prediction and neural learning software processes. This approach provides a very practical solution for a new generation of terrestrial navigational aids.
Manufacturers of autonomous robotic systems are trying to create improved navigational aids that allow their machines to traverse a path or an area without human intervention. The autonomous robotic system needs to be capable of identifying its current location in order to accurately traverse to an intended destination. Position locating is based in part upon the ability of an autonomous robotic system to interpret the data received from its sensors and applying that data to making intelligent decisions. Often the data is inaccurate or is limited in its availability. The lack of accurate information can lead to errors in navigation.
Errors in data interpretation can be caused from a variety of sources. Most often it is the data itself, which has become corrupted that leads to computational errors. We examine the possible causes of data corruption in order to isolate their effects and to account for them.
In order to reduce navigational errors, we look towards limiting environmental conditions that are expected to work against us. For example, limiting the distance between a transmission source and a receiver can limit the obstacles that can lead to a reduction in signal quality while also enhancing signal strength.
Signals of terrestrial origin include sources such as radio signals, television broadcast signals, cellular telephone signals and wireless network signals normally used for the purposes of communication. In the applications contemplated herein, such signals are used to provide time components that can be correlated with measurable distances and used for the purposes of navigation. These data can be used to provide methods to calculate a distance between a source and a receiver. The new digital signal sources available to us can be usefully employed in this type of navigation.
In the prior art, these transmissions have often been provided as unsynchronized signals. In such cases, there is no basis for making accurate time and distance measurements. The availability of high quality digital transmission formats provides an opportunity to employ communication towers for the purposes of navigation.
In some embodiments, advantages of signals of terrestrial origin over non-terrestrial sources such as GPS include a reduction in propagation distances, an increase in signal strength, reduction of intervening atmospheric conditions, and elimination of motion of the signal source, such as positional changes in orbit.
One approach to utilizing these environmental signals is through a process of time differentiation. When an incoming signal, such as that from a HD radio signal is received, a time differential can be calculated between the time a signal is transmitted and when it is received. This differential reveals a distance measurable component by multiplying the time of travel by the known speed of travel of electromagnetic waves e.g., approximately 186,000 miles per second, the speed at which radio waves travel in free space. Comparisons of three or more radio sources can provide enough data to perform triangulation.
Triangulation is an accurate method of determining a fixed location. An immediate recognizable advantage over non-terrestrial transmitters, such as GPS, is the fixed locations of local signal sources, such as broadcast towers. Signals broadcast by stationary transmitters eliminate issues related to positional changes or constant motion of a transmitter. Signals of terrestrial origin are becoming quite abundant as more systems that rely on digital communications come into general use.
On Oct. 10, 2002 the Federal Communications Commission (or “FCC”), approved a digital band to be used for commercial digital broadcasts. The developer of HD radio, Ibiquity, was granted permission to broadcast their digital IBOC, or In-Band-On-Channel technology for both AM and FM radio. The development of digital broadcasts makes available one source of components that can be used for programmable robotic technology.
Currently there are hundreds of radio stations that have applied HD radio broadcast technology. AM HD radio transmits between 540 KHz-1.6 MHz, while FM HD radio broadcasts can be found between 88-108 MHz.
Today there are approximately 800 television broadcast stations transmitting HD digital signals and more are coming online each year. There are three frequency ranges that make up local television broadcasts and they include; 54-88 MHz, (channels 2-6), 174-216 MHz, (channels 7-13) and, 470-890 MHz, (channels 14-83).
Cellular communication towers are becoming ubiquitous and are available in large numbers. A restricted radiated output, or operating range, increases the number of overall towers required for uninterrupted service. The frequencies for which the towers operate fall between 824 MHz.-894 MHz, although the transmission frequency range is not continuous.
Communication between a tower and a cell phone occurs automatically upon powering the phone hardware. This is evident by the display of reception bars that are commonly located on the display of a typical cellular telephone instrument. This two-way communication occurs even with the lack of a service agreement, which prevents a user from conducting a conversation other than for 911 type emergencies. Although coded, the phone hardware allows for passive communication that enables the use of time measurable components.
The primary use of wireless local access networks is for the purpose of communication. However alternative components also do exist. Local access networks can also provide time measurable components capable of providing navigation aids. Although somewhat limited in range, they can still provide a useful service other than for which they were initially designed. A grouping of three or more of them can provide the necessary data to perform triangulation.
Electromagnetic waves are subject to attenuation, or a signal reduction, depending on the medium through which they travel. These effects can vary in degree depending upon the type of medium and/or environmental conditions. Possible sources of attenuation include water vapor and/or physical obstructions both natural and man-made.
Water can take many forms such as vapor, rain, snow, hail and/or fog. The degree to which atmospheric water content affects radio signals is dependant upon the quantity of water present, and in general, the greater the quantity the higher the attenuation. In general, rain has the most impact upon signals as it contains a greater volume than that of snow, hail and or fog. Although snow may appear larger at times, it is not the size that determines the effect but rather the quantity of water present.
It is also important to consider the effects of attenuation upon the varying lengths of radio waves. Electromagnetic waves obey the relation λ=c/v, where λ=wavelength, c=speed of light, and v=frequency, e.g., frequency and wavelength are inversely related. For shorter wavelengths (and higher frequencies), attenuation factors become more prevalent.
One should also consider the structure of Earth's atmosphere. The troposphere, in which virtually all weather phenomena occur, encompasses much of our attenuation effects upon radio propagation. It extends to 3.7 miles at the North and South Pole, and 11.2 miles at the equator. The Stratosphere, which is found between the troposphere and the ionosphere, has virtually no effect upon propagation because of its lack of water vapor and environmental change. Beginning at approximately 31.1 miles above the Earths surface and extending to about 250 miles, the ionosphere has a profound effect upon long distance communications. It contains electrically charged ionic layers that make possible for signals to extend their ranges because of the reflective properties of the ionic layers. These properties however are more prevalent after nightfall.
Other related factors cover physical obstructions, such as mountains, trees and or man-made structures. In the case of mountains, signals can shadow areas situated on the side opposite from the signal source. In some instances, the topography of terrain can cause a reduction of signal power. Typically, the greater the conductivity of the earth's surface, the less the attenuation effects. Trees or foliage can pose an interesting challenge as they tend to be vulnerable to position change caused from wind. Their movement can have varying effects upon signal transmission as well as the density of the foliage itself that may cause scattering. Man-made structures present multiple opportunities for attenuation factors, some of which may include multipathing, reflections, scattering and absorption.
Controlling the effects of signal attenuation may rely on the whether the nature of the disturbance is predictable. Man-made structures such as buildings can be plotted to reveal expectations for signal propagation effects, and some of their effects can be measured.
In the search for a reduction in signal attenuation, we first examine the simplest explanations. Limiting physical and geographical obstructions is a good place to start. Of course a reduction in distances between antennas can often achieve the same result while also enhancing signal strength. These steps most often work however occasionally there are instances where more is required. In this case one may consider employing methods such as prediction through repeatability. It has long been accepted that environmental attenuation is far too complex to solve or even control.
There is a lack of uniformity when it comes to environmental conditions. In general, it is unlikely that there are two areas that is expected to be similar enough to predict results. Instead we employ a system of environmental adaptation through repeatability. We begin with base line expectations for environmental conditions. Our results improve with repeated visits within an area of interest by recording the results for later consideration. The environmental adaptation is for the most part site dependant. In general, a new platform is capable of base line values and is expected to be required to learn from repeated operation. Each time the apparatus traverses the area; it attempts to predict signal attenuation and compensates for any distortion.
Arrays of sensors begin by interpreting the environmental conditions. The results from sensors such as humidity, barometric pressure, temperature, moisture and solar radiation, to name a few, are then assigned numeric values. They become assigned weights for the individual neural nodes within a network. This relationship can be best be described simply as Y=F (X), where X represents an Input and F (X) describes the mathematical relationship that produces the Output Y. Based upon their values, weights can either enhance or reduce the neural nodes outputs thereby affecting their outcome.
The decisions from the sensor network is expected to directly effect how the apparatus interprets its received radio signals. The effects upon the neural output is expected to be in proportion to the changes in environmental conditions and prerecorded referenced data. The constant considerations of previous environmental data is expected to allow for an ever changing output response.
To create some uniformity, each robotic apparatus contains base line values for varying environmental conditions. With repeated exposure to familiar areas, the robot is expected to adapt to possible signal distortions through associative memory and prediction. It has been shown that signal errors can be reduced through repeated exposures to similar conditions. Unfortunately these error reductions are site dependant and require each apparatus to learn from its own environment. The apparatus becomes “smarter” with added operational experience.
Radio frequency interference has long since been known to be a factor in transmission quality. Such interferences have been known to be derived from such sources as sun spots, terrestrial geography and topography, and environmental anomalies such as lightning.
In receiving RF signals from distant towers it is expected that one can have a multitude of obstructions from the environment between transmitter and receiver, such as hills and or buildings. Such obstructions could create multipath fading. This is the result of radio signals reaching the receiving antenna by two or more paths which confuses a receiver and generates noise. Additional causes may include atmospheric ducting, ionospheric reflection and refraction, and reflection from terrestrial objects.
Currently techniques used for the purpose of combating multipath fading include the use of rake receivers. This receiver is designed to counter the effects of multipath fading by using several sub-receivers each delayed slightly in order to tune in to the individual multipath components. Another technique employs a signal-to-noise ratio method (SNR), whereas the power ratio between a signal and background noise are examined.
An additional method for examining environmental signals involves the use of neural network software/hardware. By employing an array of environmental sensors such as heat, moisture/humidity and or light sensors among many, (Δx≈ΔY), data can be introduced into a processor and analyzed for a case by case study of the current environment, using a relationship Y=F(X) (see
Such neural software has the ability to learn from its environment and may be continually reconfigure its data to best suit the environment and its current conditions. Understanding the environmental conditions is expected to allow our network to best analyze the input or sensory data from environmental signals; i.e., man made structures may be present on a multitude of passes but weather conditions constantly change. Additional anomalies such as CB radios and non-conforming transmitting towers could also interfere occasionally and are expected to need to be examined on a case by case study. The introduction of neural processes could reduce the effect of environmental anomalies by understanding that in fact they do not belong.
Machines using unique identifiers signifying their identity can be tracked individually within close proximity from one another. Each signal is expected to be recognized and plotted in order to prevent multiple platforms from traversing the same area of interest. An apparatus can be sent orientation data as they relate to other machines and therefore could prevent a multiple transverse of an area or it could activate specific sensors to look for other machines. If one machine does not answer a request to “move”, then the machine communicating is expected to prevent collision.
An apparatus could look for changes in environmental readings previously programmed as base readings. They could also act independently from set programs by the use of environmental sensors inputting analog signals pertaining to the environment. Such sensors could include, rain sensors, heat, smoke, biological, touch/pressure, etc. These sensors are expected to play a significant role in understanding its environment through sensory input. These base readings are expected to be used to alter the effects of environmental signals to adjust for any interference.
This algorithm is expected to examine data from sensory inputs, such as those from environmental programs, whereas it is expected to determine whether there is a threat. Data from diagnostic programs is expected to also send data here for calculation and assessment. This algorithm is expected to make a determination and transmit an action pulse to output controls such as drive train motors, giving a command to reverse and or stop. These evasive maneuvers are not held to reversing and or stopping but should be represented by any action other than a preprogrammed directive.
This algorithm is expected to examine signals from both mechanical/electrical systems. If electrical pathways or circuits become damaged, sensors are expected to detect the break or malfunction and are expected to look to correct and possibly reroute signals to a back up system. This could be achieved by having a series of “common” pathways. This allows for multiple signaling along the same pathway. Mechanical failures are detected when an output signal is received and yet there are no responses. For an example if a command is sent to the motor outputs to transverse forward, wheel rotations, compass, and other navigational instruments should be detecting a change in position. If a change is not detected or wheel rotations have not begun, then there is expected to be a failure detected. The diagnostic program is expected to have “override” power to control circuits to enable safety methods.
This allows for a user to call out a new coordinates to the apparatus to transverse an additional area of interest. This is expected to allow a user to reprogram for newly planted shrubs, trees, and or any other obstruction without total reprogramming. The program is expected to override preprogrammed commands and allow for input of new instructions. Another redirection purpose is expected to be for security applications where a programmer could send out a new coordinates for investigation. Either by a user and or automatic alarm response triggered by alarm sensors, the apparatus could investigate the area and return later to the original point of redirection.
This algorithm examines the communications between multiple machines and or base stations. When a transmission signal is being sent it is expected to look for a receiving signal that is returned giving notification of a successful transmission. Should there be no receiving signal, it is expected to look to correct the problem through diagnostics. It could either be the transmitter and or receiver that might have failed to operate. Each transmitter has a unique identifier from which can give individual identification. This program is linked to self-preservation.
This algorithm is expected to monitor tool functions and the commands that control them. Here a command signal is given and a response is expected. If after a command there are no proper functions detected, then the program is expected to look to perform diagnostics.
This algorithm is expected to examine the operations of sensors responsible for navigation. Signals from these sensors are expected to be monitored for both overall operation and resulting outputs. A comparison of the navigational signals and, actual environmental sensors, is expected to indicate proximity to objects and platform movements.
Communication between algorithms is essential to proper operation. Each has specific operations to perform. Having sensory data sent to a common pathway is expected to allow all algorithms to seek for specific bits at the same time. This is expected to speed up the transfer of information by parallel means rather than series decisions. Each neuron of the human brain is connected to at least 1,000 others and as many as 10,000. The transmission speed between them is 200 mph. Though this is slow compared to computer transfer speeds, it is the magnitude of the connections that make up for the speed. This is the model for our neural networks. The multiple connections within common pathways with specific neurons assigned specific algorithms.
We can use neural networks for learning or adaptation. This allows the system to constantly adapt to a series of changes, allowing for a memory to be rewritten over time (“adjusted memory”). Information collected during operation is expected to be mixed with old data and a new memory entry is expected to be produced with a new or updated signals. Former output results might be compared to current analysis in order to assist in making a decision. Similar bits from previous actions could be collected and mixed with current bits to make an intelligent calculation. This is expected to allow for an environmental change that effects a signal reception and over time the memory accounts for this change. The important factor is that the memory change happens over time and not with a single detection thereby looking for a permanent pattern change in the environment.
The systems and methods of the invention can also use a learning algorithm. Learning algorithms are those that are modified during use by applying information collected during operation to existing data or information. The algorithm is modified to produce with a new or updated method that provides an improved output. In some embodiment, old results are compared to current analysis in order to assist in making a decision how to update parameters in the algorithm, for example coefficients in a fitting equation.
Elaborating more on the concept of master/slave relationships, to allow for a more accurate information transfer of human movements. A user might employ a robotic exoskeleton to different parts of his/her body to digitize the actual movements. The exoskeleton may require the same tooling as the slave unit in order to better control exact behaviors. The exoskeleton is expected to convert movements into digital signals for both recording and transmitting to a slave unit and or other host. Upon receiving the digital signals, the slave unit is expected to mimic the exact movements of the original user. This provides for a faster programming capability of complex mechanical movements that is expected to otherwise take enormous programming code. Users could purchase a slave robot with no programs and later purchase the software for specific job functions. i.e., dishwashing, planting, picking fruit, general cleaning, etc. A user is expected to purchase a dishwashing program, bring it home and upload the program into the slave. Programs could consist of a single action and or multiple repetitive actions that combine for intelligent recognition, i.e., a dishwashing program might have 50 different washes stored. Each wash cycle has different types and sizes of dishes and each uses different washing methods. Upon reading the multiple programs, it either choose an exact program or simulate a new program by combining various bytes of data from each program to match current conditions.
The following steps provide information and instructions to be recorded on machine readable medium:
Data is read from the memory modules which provide;
Data is read from the memory modules which provide;
Playback # 2 procedures are repeated thereafter
This represents the method for which Environmental conditions are expected to affect the output of navigational commands regarding course corrections. Environmental sensors are expected to be fed into the computational process at points of W1 & W2. These weights are expected to inhibit, remain neutral, and or amplify the input values of Environmental signals. This is expected to allow for adjustments in weather conditions.
This method is expected to allow environment weather conditions to affect directly the output of environmental signals, thereby adjusting for change and avoid program confusion. Over time, weather and or environmental sensor data is expected to be capable of predicting signal behavior by comparing stored data with similar results.
Autonomous navigation using terrestrial signals versus non-terrestrial signals, such as those from local transmission sources is described. In one method of robotic navigation, one uses environmental signals from local transmission sources, to determine one's location using such techniques as time differentials and triangulation. The environmental signals from local transmission sources can comprise one or more of radio signals, cellular telephone signals, television broadcast signals, and wireless networks. Each type of signal has its own characteristics. The methods also can consider and take into account variables that can affect signal propagation, such as transmission distances, man-made and natural obstacles, atmospheric effects, and the effect of weather on signal transmission. Methods for limiting and overcoming signal attenuation that can be employed include one or more environmental sensors, perhaps in networks (such as weather or meteorological sensors), repetition and redundancy, predictive methods, and analysis of effects of the local terrain or site. Applications of the technology can include use in navigation and location for military and/or security purposes, for agricultural applications, for landscape maintenance, for construction, and for other tasks that are repeated from time to time, such as snow removal.
There are several different applications.
One describes a user requesting a location. The request is sent to programmable platforms on the perimeter of a region, whereby when a user requests a point, each of at least two platforms is expected to spin and orient itself to align with that point, whereby each fires a laser line that intersects the users original point request. The use of two lasers mean an intersection point, or “cross-hair,” is seen by the user. These lasers are “wall” lasers that deploy a spinning mirror aligned horizontally, whereby when activated, the laser line can be seen along the floor and or ceilings at the same time because of the spinning action. These lasers are not point lasers. No linear measurement is required. Because each laser knows it own position, no matter what position the user requests, the laser can orient itself to activate its tool function. Each laser line is expected to pass through the requested point, thereby creating a cross hair appearance. The user then can “mark” the spot requested.
The second laser system deploys a perimeter system with strips of laser diodes along the perimeter. These strips are expected to contain laser diodes capable of firing laser light clear to the other side of the area of interest. The system is expected to simulate an x,y grid. There are expected to be a plurality of strips aligning the perimeter. In a Cartesian coordinate embodiment, one represents “x” and the other represents “Y”. Movement of the platform consists of a coordinated firing of lasers allowing the platform to “follow” or “track” the positions of light. In this embodiment, as many obstructions as possible be removed from the operating area. However coordinated light pulses can direct a platform.
Yet another method involves a current programmable system “marking” the floors with paint and or lasers, to layout a building for construction. The system is set up for this already, being that it is a programmable device performing a tool function, whether it be in motion and or at rest. The tool function is expected to be the marking system.
In one example, a workman, such as a plumber, walks upon a concrete pad, whose dimensions are 100′ by 150′. He begins by strapping on a harness which holds a laptop computer and a back pack that contains radio equipment. He places a disc into the drive, the disc containing information about a plumbing system to be laid out. On the screen comes a CAD image detailing the plumbing layout. He begins by selecting an area to layout by clicking on a particular pipe identified on the drawing. As he clicks on that item, the computer sends that request to the radio transmission equipment contained on his back. The data is sent wirelessly to robotic lasers bordering the concrete pad.
This transmission is not unique to one platform but can be read by any robotic platform within the receiving area. The signal is received and converted from an x, y coordinate to an angular determination based upon the individual platforms location on the pad. Each robotic platform when placed earlier on the pad, calculated where they were in relation to the CAD drawing. This is achieved through laser positioning from survey points.
The robotic platform once converting the coordinates to an angular determinate then turns to align itself on that particular angle. Once alignment has been completed, the platform activates a laser device essentially firing a laser line along that vector. There is no linear measurement involved here but simply a creation of a highlighted vector. A location is derived when two or more lasers cross lines.
Each laser independently derives its own alignment and fires a laser line that is designed to exceed the point of interest. This overlapping is deliberate as the true measurement comes when two or more lasers meet. The benefit here is that there is no linear measurement involved by either radio or laser sources. Such sources have limitations in accuracies whereas criss-crossing vector lines seems to reveal a more accurate method.
This exemplary description of one particular tradesman is not limited to any one trade. This method can be deployed in a variety of applications involving positioning of walls and or mechanicals.
In one embodiment, each platform is expected to employ a digital magnetometer to identify bearings. These along with high resolution of gears is expected to determine angular determinants. Each robotic platform is expected to be programmable. They are expected to possess CAD specifications for each task. Each coordinate is then calculated to reveal necessary alignment. Each platform is expected to possess adaptable mounting harnesses unique to each particular brand of laser deployed. Each platform is expected to have a radio receiver module for the purposes of communication with a user. Each platform is expected to possess a motor control module. Each platform is expected to possess a CPU module for essential computations and overall control of other modules. Each platform is expected to operate autonomously from a user in determining fixed locations.
A robotic platform is activated to begin traversing a concrete pad. At either end of this concrete pad, there are laser diodes contained within a plastic boarder. When activated, the robotic platform is expected to traverse along projected laser beams. These beams are expected to essentially guide the robotic platform similar to a railroad track, keeping it in check with the preset pathway.
These projected pathways can be alternated creating new guided pathways. A computer control module is expected to designate which diodes to activate and from which angle. Each pathway can either be straight and or angular. Each beam may also cease before the robot reaches the end as it may be directed to change coarse by activating an alternate beam while in motion.
A guided pathway may involve several projected beams, each from different positions before completing a task. Each platform is expected to possess sensors sensitive to laser light that is expected to control the platforms movement. Processing the position of the laser light is expected to reveal where the platform is in relation to the laser source.
In one embodiment, each robotic platform is expected to possess laser light sensors. Each Robot is expected to have a sensor control module. Each platform is expected to have a motor control module. Each platform is expected to have electrical communication between sensor and motor control modules. Each platform is expected to possess a central processing module. Each module is expected to possess a memory module in communication with CPU module. Each CPU module is expected to have communication with both motor control and sensor modules. Laser diodes are expected to be controlled by a CPU module. Each laser strip is expected to possess a memory and CPU modules. Pattern generation is expected to come from CPU and or memory module. Each laser strip is expected to possess radio receiver modules. Each robotic platform is expected to possess radio transmitter modules for communication with laser strips.
Those of ordinary skill will recognize that many functions of electrical and electronic apparatus can be implemented in hardware (for example, hard-wired logic), in software (for example, logic encoded in a program operating on a general purpose processor), and in firmware (for example, logic encoded in a non-volatile memory that is invoked for operation on a processor as required). The present invention contemplates the substitution of one implementation of hardware, firmware and software for another implementation of the equivalent functionality using a different one of hardware, firmware and software. To the extent that an implementation can be represented mathematically by a transfer function, that is, a specified response is generated at an output terminal for a specific excitation applied to an input terminal of a “black box” exhibiting the transfer function, any implementation of the transfer function, including any combination of hardware, firmware and software implementations of portions or segments of the transfer function, is contemplated herein.
While the present invention has been explained with reference to the structure disclosed herein, it is not confined to the details set forth and this invention is intended to cover any modifications and changes as may come within the scope of the following claims.
This application is related to the following applications and patents: co-pending U.S. patent application Ser. No. 11/740,654, filed Apr. 26, 2007; U.S. patent application Ser. No. 10/631,465, filed Jul. 31, 2003, issued as U.S. Pat. No. 7,239,944 on Jul. 3, 2007; U.S. patent application Ser. No. 10/603,572 filed Jun. 25, 2003, issued as U.S. Pat. No. 7,103,457 on Sep. 5, 2006; U.S. patent application Ser. No. 10/401,266 filed Mar. 27, 2003, issued as U.S. Pat. No. 7,107,132 on Sep. 12, 2006; U.S. provisional patent application Ser. No. 60/368,196, filed Mar. 28, 2002; and U.S. provisional patent application Ser. No. 60/812,231, filed on Jun. 9, 2006, each of which applications and patents is incorporated herein by reference in its entirety.
