The present invention relates to systems for monitoring the position of objects relative to other objects, and more specifically to such systems that provide a warning to vehicle operators of the upcoming proximity of vehicles relative to each other.
Vehicle proximity alert systems are known for automobiles and trucks traveling on conventional roads, where each vehicle transmits a signal that is received by other vehicles. As the vehicles move closer to each other, the nature of the signal changes, alerting the operator that a vehicle is approaching, such that the operator can adjust the speed or direction of travel of his vehicle. In some cases, the systems automatically adjust the speed or direction of the vehicle as needed.
In the case of vehicles traveling on railroads, such as trains and railway maintenance vehicles, the operator or engineer relies ultimately on his vision in gauging the relative position of nearby vehicles on the track. However, in some cases, such as inclement weather, or geographic obstacles such as mountains, hills, depressions, curves in the railroad, or the like, it may be difficult to see another vehicle on the same track that is in close proximity to the operator's vehicle. Once another vehicle is seen on the track, the operator can adjust his speed, but not his direction. In many cases, there are long distances to the next crossing, track intersection, siding or switch area, so rapid change of direction is usually not an option. Also, due to the relatively heavy rolling mass of trains and railroad maintenance machinery, and the potentially relatively low coefficient of friction between steel rail wheels and steel track, it is difficult to stop a rail vehicle in a relatively short distance. Thus, rail vehicles have relatively longer stopping or braking distances than vehicles with rubber tires travelling on conventional roads.
Conventional vehicle proximity systems have been unsuitable for use with railroad vehicles due to the problems created by geographical obstacles, turns, dips or curves in the track and the longer stopping distances. For example, ultrasonic transmitters are unsuitable for use around curves in the track, and often generate false alarms caused by objects located along the track such as removed ties and other types of railway components. Doppler radar transmitters require visibility between the respective vehicles and as such are less effective when hills, mountains or other obstacles are present. Also, objects located along the track generate false alarms, which frustrate the operators, who then often disable the systems. Another drawback of Doppler transmitters is that they operate by calculating changes in distance between vehicles, rather than the exact distance. Conventional radar does not operate effectively around geographic obstacles, is impaired in bright sunlight, and is less accurate as distances increase between vehicles. Thus, there is a need for a more reliable warning system for alerting operators of rail vehicles as to the proximity of other objects, personnel and/or vehicles within a specified distance of a target or subject object, such as a vehicle.
Accordingly, the above-listed needs are met or exceeded by the present object proximity system which provides an alert to the operator of a moving object, such as a vehicle that the vehicle is approaching another fixed or moving object, including but not limited to a stationary or moving vehicle, fixed object or individuals such as railway maintenance workers or the like, and that at least one of speed and direction should be adjusted in the present object. An advantage of the present system is that it has a range exceeding that of the vision of the operator, and can better cope with geographic obstacles such as mountains, hills, depressions, curves in the direction of travel, or inclement weather, etc. In addition, the present system is designed primarily for alerting the operator to the proximity of another object, and as such is relatively simple with few components and reduced maintenance costs. The present system also is designed to provide the operator sufficient warning time for permitting corrective action, given the relatively longer required stopping distances of railroad vehicles.
Another feature of the present system is that the intensity, as in frequency or volume of the alarm increases as the distance decreases between the respective objects. A related feature is that the data processor is configured such that the target distance changes with the speed of the present object, sometimes referred to in this application as the subject vehicle, wherein target distance shortens as vehicle speed decreases. Also, the present system sends warning signals to at least the present object and the next adjacent object in the system, as well as optionally to other objects within a prescribed geographic area. Still another feature is that the present system detects other objects connected to the system relative to both forward and rear ends of the present machine. In applications where monitored machines or vehicles are intentionally in close proximity to each other, the present system features a temporary manual override of the alarm triggers.
In the present system, each object has three main components: a global positioning system (GPS), a radio transceiver and a central data processing unit (DPU). Each object continually transmits at least its position. Further, the transceiver receives the position data transmitted by other objects connected to the present system. The DPU in each vehicle or other object receives the respective position data of the present object and the other objects connected to the system, and determines whether the present machine is within a prescribed target distance of another machine in the system. If two machines are within the prescribed distance, an alarm is generated.
More specifically, the present object proximity alert system is provided for use with an object network, and includes an object module having a GPS unit and a transceiver both connected to a data processing unit. A first object in the network has the object module, such that the data processing unit obtains first object position data from the GPS unit, calculates object speed and transmits the position data using the transceiver to other network vehicles. The data processing unit calculates the respective positions of the first object with other objects in the network based on the data, and compares the position data against a preset target separation between the first object and the other objects. In the event a separation distance between the first object and another object in the network is less than the target separation, the data processing unit generates an alarm in at least the first object.
Referring now to
While the following description is provided in relation to the first object or subject vehicle 12, it will be understood that the system 10 contemplates several such monitored objects or vehicles, each equipped with similar equipment as described below. One of the purposes of the present system 10 is to determine the relative proximity of objects or vehicles connected to the system. A main objective of the present system 10 is to provide machine operators information about other network-connected objects or vehicles which are in close proximity to their particular object or subject vehicle. If the subject vehicle is within a specified target distance of another vehicle in the network, an alarm is triggered by an onboard data processing unit. The purpose of the alarm is to alert the operator to adjust the speed of his vehicle for preventing the subject vehicle and a next adjacent vehicle from achieving the same position.
The vehicle 12, as well as other similar vehicles in a network 14 of such vehicles, is provided with an object module 16, also referred to as a remote terminal unit, including a data processing unit 18 such as a computer or the like, a GPS unit 20 electrically connected to the data processing unit and a transceiver or Short Range Radio module 22 connected to the data processing unit. The transceiver 22 is at least one of a radio transceiver, a cellular transceiver and a satellite transceiver, and has a respective antenna 24. In the preferred embodiment, the transceiver 22 is a radio transceiver. In addition to the GPS 20 and Short Range Radio module 22 in the system, a GSM/CDMA/Satellite Radio module 25 is optionally included. The module 25 allows connectivity with a remote server (not shown) so that the data can be stored in a remote database and the system 10 can be controlled by the server. As is known in the art, the GPS unit 20 and the Satellite Radio module 25 also have a corresponding antenna 26, 26′. Power is supplied to the system 10 through the vehicle electric system, typically operating at 12 to 24 Volts as is known in the art.
The module 16 is electrically connected, by inputs/outputs 28 such as wires or wirelessly, as is known in the art, to an operator interface panel 30 located in the vehicle 12, as in an operator cab or workstation, as is well known in the art. Shown schematically, the operator interface panel 30 is contemplated as taking a variety of forms of controls and displays, and in the preferred embodiment includes a proximity warning display 32, having at least one first visual warning display 34 and at least one second visual warning display 36. In the preferred embodiment, the first and second visual displays 34, 36 are different colors, for example yellow and red, to indicate the progressive proximity of the first object 12 to a closest second object 38, also preferably but not exclusively a vehicle, in the network 14. Thus, as a separation distance “D” (
In addition to the visual alarm displays 34, 36, the operator interface panel 30 is provided with an audio alarm 40. As an option, the object module 16 is provided with a tactile alarm (not shown), which alerts the operator by vibration transmitted through various vehicle controls, such as joysticks or the like.
As will be described in further detail below, the operator interface panel 30 is provided with at least one, and preferably a pair of override controls, including a temporary override 42 control and a towing override 44 control, each having a visual indicator 46 to display when the override is activated.
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The data processing unit (DPU) 18 is preferably configured so that the visual alarm displays 34, 36 are triggered upon preselected distances between the first object 12 and the closest object 38. These distances are monitored by interaction between the GPS unit 20 and the data processing unit 18. For example, the first visual warning display 34, preferably displaying yellow or another relatively low alarm level color, is triggered when the distance D is less than a preselected distance, but providing the operator or user with plenty of time to reduce speed. For example, while the object 12 is in a traveling mode, traveling upon the track at speeds greater than 10 mph, the first visual warning 34 is triggered when D is 450 feet or less. Then, as D is reduced, as the objects 12 and 38 become closer together, the second visual warning display 36, typically red or another color designating a higher alarm level, is triggered by the data processing unit 18. For example, the display 36 is triggered when D is 300 feet or less, providing the operator sufficient time to take effective action so that the objects 12 and 38 do not occupy the same position. It is contemplated that the specific trigger points and speeds may vary to suit the application.
It is also contemplated that the system 10 is designed such that the above-described target distances preferably vary as a function of the speed of the object 12. Thus, in addition to the above-identified alarm trigger points, the data processing unit 18 is programmed with a second set of alarm trigger points intended for use when the object 12, such as a railway maintenance machine, is in a working mode on the track, and traveling at a relatively slow speed, such as 5 mph or less. In such situations, the objects 12, 38 need less distance to stop before the situation occurs where their positions coincide. During the working mode, the first visual alarm display 34 is preferably triggered when D is 150 feet or less, and the second visual alarm display 36 is triggered when D is 75 feet or less. In other words, the color of the alarm varies as the distance D decreases between the objects 12, 38, and the data processing unit is configured for changing the alarm trigger points based on the speed of the first object 12.
In addition, there is still another alarm trigger point algorithm based on the projected time separation between objects 12 that are becoming closer together and measures a time at which both objects will occupy the same space. In a preferred embodiment, a “yellow zone” begins at 30 seconds prior to such occupation, and a “red zone” begins at 15 seconds prior to such separation. Thus, the data processing unit 18 is configured for changing an alarm trigger point based on the projected time separation between the first object/subject vehicle 12 and another vehicle 38 whose separation distance is decreasing.
Referring now to
For a given object or vehicle 12, the current data transmission is calculated by T=nt, and speed (speed is available in the data packet from the preferred GPS. A rate of change in distance between two objects is calculated by data received in multiple transmissions.) is calculated by comparing with the next previous data transmission, calculated as T=(n−1)t, to determine the speed of the object. Once the speed of the object 12 is determined by the data processing unit 18, this data is compared with the received position data from the other objects 38, etc. and the alarm trigger point is set. In other words, the data processing unit 18 determines an appropriate target distance for the first object 12 based on speed, and the position of the next adjacent object 38 in the network 14, including a projected point where positions of the first object and the next adjacent object coincide. As seen in
Referring now to
Alternately, the towing override control 44 is contemplated for use for longer periods of time, when one object 12, 38 tows another, and as such the objects are within the target distance of each other, which under normal circumstances would trigger an alarm. In the towing mode, the engine of one object will be turned off, and pressing the tow override control 44 will terminate communication between the first object 12 and the system 10. When operating in this mode, no other alarms are activated or displays shown. Once the user activates the designated control 42, 44 only the display 46 is illuminated. In the event the engine is turned on, the towing mode 44 is reset.
In addition, the data processing unit 18 is preferably configured so that the user can temporarily disable the transceiver 22, and an alarm is generated if the GPS unit 20 loses its signal. Another preferred feature of the system 10 is that each object 12, 38, has a distinct identification signal that is transmitted to each other object in the network 14. Still another feature of the system 10 is that it remains active even after the engine of the object 12, 38 is turned off.
Another feature of the system 10 is the capability for updating the control software or firmware remotely by wireless connection. In addition, the system 10 has a serial port for use in debugging. The system 10 also supports CAN bus interface 50 (See
While a particular embodiment of the present object proximity system has been described herein, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims.