Patent Application
20130173056
The present disclosure relates to a short-range sonar system. More specifically, the present disclosure relates to a small scale sonar system configured to operate at short-ranges.
Existing sonar systems, such as ultrasonic sonar systems, are useful in determining a distance between the sonar system and a solid object. However, due to the physical characteristics of typical sonar systems, they do not provide as narrow a focus as may be desired for short-range operations. As such, due to these technical limitations, existing sonar systems typically cannot detect an object closer than about 200 millimeters.
Many devices utilize short-range sonar systems. For example, robots such as automatic vacuum devices use a combination of short-range sonar and long-range sonar. Using this combination of short and long-range sonars, a robotic device can detect objects between 200 millimeters and 2.5 meters away. However, for use in cramped environments such as a home cluttered with furniture and other objects, this range may not be adequate to provide the robotic device with an appropriately functional sonar system for its surroundings.
This disclosure is not limited to the particular systems, devices and methods described, as these may vary. The terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope.
As used in this document, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art. Nothing in this document is to be construed as an admission that the embodiments described in this document are not entitled to antedate such disclosure by virtue of prior invention. As used in this document, the term “comprising” means “including, but not limited to.”
In one general respect, the embodiments disclose a short-range sonar assembly. The assembly includes a local controller operably connected to a processing device and configured to receive instructions from the processing device, a first transducer operably connected to the local controller, a second transducer operably connected to the local controller; and a flared bell configured to house the local controller, first transducer, and second transducer. The flared bell includes a first enclosure configured to receive and house the first transducer and a second enclosure configured to receive and house the second transducer.
In another general respect, the embodiments disclose a robotic device. The robotic device includes a processing device, a short-range sonar assembly, and a transportation mechanism operably connected to the processing device and configured to move the robotic device in various directions in response to instructions from the processing device. The short range sonar assembly includes a local controller operably connected to the processing device and configured to receive instructions from the processing device, a first transducer operably connected to the local controller, a second transducer operably connected to the local controller, and a sonar horn configured to house the local controller, first transducer, and second transducer. The sonar horn includes a first enclosure configured to receive and house the first transducer, a second enclosure configured to receive and house the second transducer, and a third enclosure configured to receive and house the local controller.
In another general respect, the embodiments disclose a method of detecting objects with a short-range sonar. The method includes transmitting, via a first transducer, one or more pulses, wherein the first transducer is mounted in a first enclosure such that the one or more pulses are transmitted in a narrow beam; receiving, via a second transducer, the one or more pulses as echo pulses having reflected off an object, wherein the second transducer is mounted in a second enclosure such that the echo pulses are received as a narrow beam; detecting, at a local controller operably connected to the second transducer, the echo pulses; and determining, by a processing device operably connected to the local controller, a position of the object.
As used herein, a “robot” or “robotic device” is a stand-alone system, for example, that is mobile and performs both physical and computational activities. The physical activities may be performed using a wide variety of movable parts including various tools, for example. The computational activities may be performed utilizing a suitable processor and computer readable memory devices, e.g., a data memory storage device, for example. The computational activities may include processing information input from various sensors or other inputs of the robotic device to perform commanded functions; processing the input information, as well as other data in the memory stores of the robotic device, to generate a variety of desired information; or outputting information that has been acquired or produced by the robotic device to a desired destination, for example.
“Short-range” sonar refers to a range from 0 mm to about 900 mm from a sonar system. For example, a short-rage sonar system according to an embodiment of the present disclosure may be configured to detect objects between 100 mm and 900 mm away from the sonar system. In an alternate embodiment, a short-range sonar system may be configured to detect objects between 50 mm and 900 mm away from the sonar system.
“Long-range” sonar refers to a range 1000 mm to about 9500 mm from the sonar system. For example, a long-rage sonar system according to an embodiment of the present disclosure may be configured to detect objects between 1000 mm and 9500 mm away from the sonar system.
The sensor portion may include various components such as a short-range sonar assembly 112, a long-range sonar assembly 114, and other various sensor mechanisms such as a laser-based sensor, a global positioning system (GPS) device, a microwave sensor, and other similar sensors. The control portion 120 may include a processor 122 and a tangible computer readable medium 124 such as a hard drive, an optical drive, a flash drive, a read-only memory or a random access memory. The transport portion 130 may include a mechanical system of wheels or an electromechanical system, for example, for moving the robotic device from one place to another.
The components of the robotic device 100 as described may be configured to perform a wide variety of operations. The processor 122 may monitor and controls various operations of the robotic device 100. The computer readable medium 124 may be configured to store a wide variety of instructions and/or data used by the processor 124 as well as the other components of the robotic device 100.
The block diagram of
The design of the horn 202 may be based upon the intended function of the assembly 200, i.e., to provide a short-range sonar assembly. The horn may have various specific design characteristics such as a lip or outer diameter 220, a rim or inner diameter 222, and a curved sidewall 224 that together form or define an opening or bell. The shape and design of the horn 202 may concentrate signals emitted from the sensors 206 be directed in a narrow beam such that any received echo signals are received in a similarly concentrated beam. For example, the sensors 206 may be placed within the horn 202 such that pulses emitted from the sensors are confined and concentrated by the bell shape of the horn, resulting in a narrow beam of emitted pulses. This narrow beam, and a resulting narrowly focused echoes or returned signals, allows the sensor assembly 200 to be configured to operate as a short-range sonar assembly. The horn 202 may be designed to minimize impedance mismatch between the sensors' face and the air of the environment in which the robotic device is operating. Specifically, the lip or outer diameter 220 may contribute to minimizing any impedance mismatch.
In an exemplary embodiment, the inner diameter 222 may be slightly larger than an outer diameter of the sensors 206, e.g., the sensor's outer diameter may be 18 mm and the horn's inner diameter may be 20.6 mm. The horn 202 may be further designed such that the curve 224 defines a slowly expanding cavity 226 between the sensors 206 and the outside of the horn. The outer diameter 220 may be approximately equal to the inner diameter 222 plus the distance of curve 224. However, it should be noted that the specific design of horn 202 as shown in
In an exemplary embodiment, each of sensors 206 may be a short-range sonar transducer. One of the transducers may be configured to transmit sonar signals while a second transducer is configured to receive any echoes or returned signals. In a typical short-range sonar, a single transducer is used for both transmit and receive. However, this arrangement requires a period of time to switch the transducer between transmit and receive. The multiple transducer arrangement as shown in
An exemplary sensor 206 may be a tunable ultrasonic piezoelectric transducer. The transducer may be configured to operate at approximately 40 KHz, +/−1.0 KHz, and having a 1.5 KHz bandwidth. The transducer may have a transmitting sound pressure level of approximately 115 dB at 40 KHz, and a receiving sensitivity of approximately −70 dB at 40 KHz. The transducer may be configured to output beam or set of pulses having a transmission angle approximately 30° wide, which is further narrowed by the geometry of the horn 202 as discussed above. Depending on the application of the transducer, the transducer may be tuned to produce a specific band of transmitted signals, and similarly tuned to receive a specific band of echoed signals.
The various components may be physically held within the assembly 200 by a backplate 210 removably attached to the horn 202 via a plurality of fasteners 214. The fasteners 214 may be screws, bolts, clips, or other similar removable fastening devices.
Sensor driver 404 may be operably connected to the transmit transducer and configured to receive an instruction from the logic controller 402 to begin transmitting pulse signals. Upon receipt of the instruction, the sensor driver 404 may drive the transmit transducer to begin transmitting the pulses accordingly. Similarly, the sensor driver 406 may be operably connected to the receive transducer and configured to receive any echoes detected by the receive transducer. Any received pulses may be transferred from the sensor driver 406 to the logic controller 402 for further processing and transmission to the processing device.
It should be noted the inclusion and arrangement of the components on PCB 208 as shown in
The receive transducer may be configured 506 via instructions sent from the processing device to the local controller. The receive transducer may receive 508 echoes from one or more objects in close proximity to the receive transducer. The received echoes are detected by the local controller and transmitted 510 to the processing device. The processing device may process this information to determine 512 the location of the object(s) in close proximity. The processing device may send instructions to various other components such as a motor or other drive mechanism to steer the robotic device away from or around the object(s). A software algorithm used by the processing device to determine the location of the object(s) may be able to accept or reject echoes based upon a width (in time) of the returned echoes. This software algorithm may be useful in determining whether an object is on the edge of the beam angle, or more directly in front of the sensor.
The above discussed short-range sonar may be integrated into various products and applications where detecting an object at a close distance is desirable. For example, as discussed above, automatic vacuuming devices may incorporate a short-range sonar assembly as described herein to better detect objects positioned about the vacuum device. Additionally, auto manufacturers may incorporate a similar short-range sonar assembly into various positions on a vehicle such as the front and rear bumper to detect when the vehicle is approaching another car, e.g., during parking.
Various of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art, each of which is also intended to be encompassed by the disclosed embodiments.
