MXPA96000827A - System and method to warn on the possibility of a collision, based on the dynamic deactivation capacity determined by the use of a pronostic road load - Google Patents

Abstract

The present invention relates to a warning system for a possible collision, the system comprising: a detector for determining an inter-vehicular distance between the vehicle and a front vehicle, a control logic in communication with the detector to indicate a potential collision based on a position value that is a function of a predicted route load value, the vehicle route load value being predicted for an estimated time of a future collision

Description

SYSTEM AND METHOD TO ADVISE THE POSSIBILITY OF A COLLISION, BASED ON THE DYNAMIC DEACELATION CAPACITY DETERMINED BY THE UTILIZATION OF A PROGNOSTICATED ROAD LOAD INVENTOR: SHUBHAYU CHAKRABORTY, citizen of India, residing at 2284 Pa nee, Wixom, Michigan 48393, United States.

APPLICANT: EATON VORAD TECHNOLOGIES, L. L. C. , a United States corporation, domiciled at 10802 illow Court, San Diego, California 92127, United States.

Technical Field The present invention relates to a system and method for warning about the possibility of a collision, which are based on the dynamic deceleration capacity of the vehicle determined by the use of a predicted route load.

Technical Background The availability of inexpensive microprocessors and sophisticated electronic components has paved the way for advanced solutions for safety and comfort in a variety of automotive and truck applications. As the control systems become more complex and sophisticated, they are also able to provide the vehicle operator with critical information in various degrees. Regardless of the type of information provided to the vehicle operator, it is important to consistently provide accurate information so that the vehicle operator can trust the content of the vehicle. Most operators prefer not to have any information before receiving information of dubious reliability. Recently, warning systems for possible vehicle collisions appeared on the market. These systems use an electromagnetic beam, such as the microwave, the laser or the ultrasonic beam, to detect the distance and / or approach speed between the host vehicle and a front vehicle or other object, in order to warn the driver that it could occur a collision. Obviously, it is important that these systems consistently provide accurate information to the vehicle operator. Accurate information includes warning the operator of the vehicle about the possibility or probability of a collision, but it also means that the operator should not be warned when a collision is unlikely. That is, it is not desirable for the collision warning system to give false alarms, because it could cause the vehicle operator to ignore the warning when an alarm condition actually occurs, or to completely disconnect the collision warning system. Some systems known in the prior art automatically decelerate the vehicle to maintain a predetermined tracking distance behind a front vehicle. An example of such a system is described in a United States patent application entitled "System and method for intelligent cruise control using standard control modes for engines", filed on March 1, 1995 and assigned to the applicant. of the present, the description of which is incorporated herein by reference in its entirety. Many systems in the prior art, which provide a warning about the probability of a collision, use fixed thresholds for distance measured in feet, or a forward distance that can be measured in seconds and which varies with the specific speed of the vehicle. However, such systems known in the prior art do not take into account the dynamic deceleration capacity of the vehicle resulting from the specific operating environment. Therefore, these systems could unnecessarily activate the alarm even when the vehicle is able to avoid a collision without the intervention of the driver. The warning systems of a possible collision that activate an alarm based on a fixed distance or a fixed forward distance are especially difficult to use in tractors with two-wheeled trailers due to the great variety in vehicle weights ranging from lightweight trailers to full-load two-wheeled trailers. In such applications, the weight of the vehicle can vary by 300% or more. This causes a wide range of deceleration capabilities, because a vehicle with a heavy load without throttling the fuel inlet will decelerate less quickly than a lighter vehicle when it descends a hill, and could even accelerate in that case. Likewise, a vehicle with a heavy load may decelerate more quickly when it climbs up a hill than a vehicle with a light load. In addition, heavy and medium-weight trucks will suffer greater aerodynamic drag than typical automotive vehicles. Therefore, the dynamic determination of the deceleration capability is particularly desirable in these applications which include the vehicles of class 7 and class 8. Description of the Invention It is therefore an object of the present invention to provide a system and method for an improved warning about a possible collision based on the vehicle's dynamic deceleration capability. It is another object of the present invention to provide a system and method for warning about the possibility of a collision using a predicted route load to determine the deceleration capability of the vehicle. It is yet another object of the present invention to provide a system and method for warning about the possibility of a collision using a predetermined number of route loads previously calculated to predict a future value of the route charge. It is yet another object of the present invention to provide a system and method to warn of a possible collision that takes into account the specific operating conditions of the vehicle as well as the equipment of the vehicle to determine the deceleration capacity of the vehicle. Another object of the present invention is to provide a system and method for warning about the possibility of collision that determines the value of the vehicle's path load using the parameters of the engine emitted by the engine control module of the vehicle. Another object of the present invention is to provide a system and method for warning about the collision possibility that predicts a collision based on the dynamic deceleration capability, the inter-vehicular distance and the approach speed. Still another object of the present invention is to provide a system and method for warning about the possibility of a collision which warns the vehicle operator of a potential collision only when the predicted deceleration capacity is insufficient to decelerate the vehicle in a manner that is required the intervention of the vehicle operator. A further object of the present invention is to provide a system and a method to warn about the possibility of collision which integrates the collision warning functions with intelligent cruise control functions. In the implementation of the objects indicated above and other objects characteristic of the present invention, there is provided a system to be used in a vehicle having a motor controlled by an electronic control module, the system including a distance detector to determine a intervehicular distance and approach speed and command logic in communication with the distance detector to determine the current road load of the vehicle, calculate the deceleration capacity of the vehicle based on a predicted deceleration capacity, based on the capacity of the vehicle. predicted deceleration of the vehicle in previous determinations of the vehicle's road load. In one embodiment, the vehicle also includes a motor retarder and an automated transmission in communication with the control logic, the control logic calculating the deceleration capacity of the vehicle and using the information characteristic of the deceleration of the available deceleration devices. The present invention also provides a method that includes detecting an inter-vehicular distance, determine a speed of approach based on the inter-vehicular distance, and determine the current road load of the vehicle and the deceleration capacity. The method also includes forecasting a future value of the route load based on a predetermined number of previously determined route load values and the forecast of a collision based on predicted deceleration capacity, inter-vehicular distance and Approach speed. In a preferred embodiment, the method uses Newton's technique of divided differences to extrapolate a value of the path load based on previously stored values. The advantages of the present invention are numerous. The system and method of the present invention provide a more reliable warning of a possible collision by using the current operating conditions and taking into account variations in vehicle load conditions and deceleration devices available in the vehicle, such as a transmission. automated or a motor retarder. The system and method of the present invention provide an indication of the cumulative effect of the deceleration forces acting on the vehicle when using the information emitted from the control module, so that sophisticated detectors are not required. Therefore, the present invention provides an improvement in the reliability of the information generated by a warning system of a possible collision by reducing the cases of false alarms, thereby increasing the confidence of the operator of the vehicle in the value of the warning system of the vehicle. possible collisions. These objects and other objects, features and advantages of the present invention will be easily appreciated by any person moderately skilled in this art when reading the following detailed description of the best way to carry out the invention. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a functional diagram of a vehicle arrangement provided with a collision hazard warning device incorporating the system and method of the present invention.; Figure 2 is a stepped diagram illustrating a system and a collision warning method according to the present invention, and Figure 3 is a graph illustrating the operation of a device predicting the load on the route according to the present invention. BEST MODE FOR CARRYING OUT THE INVENTION With reference to Figure 1, there is shown a graphic representation of the system and the method to warn of the danger of a collision according to the present invention. Figure 1 depicts a vehicle 10, such as a tractor of a vehicle with a two-wheeled trailer, provided with an electronically controlled engine E, coupled to a transmission assembly T by a clutch mechanism C. Although the vehicle shown in the Figure 1 illustrates one of the possible applications of the system and the method of the present invention, it is to be understood that the present invention is not limited to a special type of electronically controlled engine vehicle but also encompasses engines with functions commanded by known means using the information on the load on the route, the information on the distance and / or the information on the speed of approach described herein and illustrated in the attached drawings. In a preferred embodiment, the transmission T is preferably a stepped gear change or a gear change with a main section connected in series with an auxiliary section including a secondary shaft 12 coupled to a motor shaft 14 of the vehicle. The vehicle 10 includes at least two axes, a steering axle 16 and at least one driving axle, such as axes 18 and 20. The axles have respective wheels provided with fixing or service brake components 22, manual or Automatically acted according to specific applications and operating conditions. For example, a vehicle fitted with an ABS can assume under appropriate conditions the automatic control of braking, when the vehicle is braking and the system discovers a sufficient slip difference in one or more wheels. The components of the service brakes 22 may include wheel speed-lu sensors and electronically controlled pressure valves, for performing the control of the vehicle braking system, as described herein. The vehicle 10 also includes conventional control means operated by the operator, such as the clutch pedal 24, the acceleration pedal 26, the brake pedal 28 and an operator interface, such as a bracket with the instrument panel 30, which can comprise any of the multiple devices 32, such as lights, LEDs or LCD screens, alarms, buzzers, and the like. The bracket with the instrument panel 30 also includes several actuating devices 34, such as switches, potentiometers, push buttons and the like. The vehicle control system includes an engine control module (ECM) 40 and, preferably, includes an additional control module for controlling the transmission T, such as the control module (TCM) 42. Of course, in some applications The control of the motor and the transmission can be combined in a single electronic control module. The ECM 40 and the TCM 42 are in communication with several detectors by means of input 44 and with drive means by means of output 46. The speed sensors of the wheels (included in the braking components 22), an electronic detector of the acceleration pedal (APS) 50, an acting speed detector or switch, a clutch control / sensor 54, and a speed-acting detector 56, among many others. The vehicle also includes a collision hazard warning system 58, which preferably provides information regarding the distance and approach speed between the vehicle 10 and at least one vehicle or front object. In a preferred embodiment, the collision hazard warning system 58 is the Eaton VORAD EVT-200 collision warning system which can be obtained commercially. The impellers include a gearbox drive 60 to automatically perform a gear change within the transmission T, electronically controlled pressure valves (included among the components for braking 22) and a motor retarder 62. It is known that a motor retarder is a device used to supplement the brake linkage or service brakes during descent by long slopes and to prolong the useful life of the service brake in operations of initiations and frequent stops. The retarders can be classified as engine brakes, gas leak brakes, hydraulic retarders and electric retarders. In a preferred embodiment, the engine retarder 62 is an engine brake such as the known Jacobs engine brake. This device converts a Diesel engine generating energy into an air compressor that absorbs energy. This is achieved by cutting off the fuel supply and hydraulically opening the exhaust valve when two or more plungers approach the top dead center during the compression stroke. Although many engine manufacturers put the engine brake out of service when the cruise control is engaged, some systems could use the engine retarder when an intelligent cruise control is engaged to reinforce vehicle deceleration. This information can be used in the present invention to provide a more accurate indication of the deceleration capability. As also illustrated in Figure 1, a diagnostic module 64 can be selectively connected to the ECM 40 and preferably communicates status messages as defined in SAE J1587 published by "Society of Automotive Engineers". Automotive Engineers), whose description is incorporated herein by reference in its entirety. During normal operation, these messages will also be usable by the other microprocessors of the system, such as the TCM 42 and the warning system for the possible collision 58 and include information such as on the current speed of the motor and its torque, the position of the accelerator, en-route speed, the state of the cruise control and the speed set by the cruise control, among many others. The ECM 40 communicates with the TCM 42 preferably by the standards SAE J1922, SAE J1939 or SAE J1587 using a communication connection according to the SAE J1708 physical layer standard, all of which have been published by "Society of Automotive Engineers", whose The descriptions are incorporated herein by reference in their entirety. Alternatively, the network standard of the command area (CAN) can be used for command communications. Preferably, the collision warning system 58 communicates with the ECM 40 and / or the TCM 42 by means of a communication connection that complies with the SAE J1708 or CAN standard and communication standards substantially similar to SAE J1922 or SAE J1939 . As will be appreciated by persons of ordinary skill in the art, the various communications between the electronic controls, detectors and impellers may be modified to suit the particular needs of a specific application without departing from the spirit or scope of the present invention. Similarly, the different communication connections and protocols can be adjusted with suitable translators or transformers. For example, in one embodiment of the present invention, the distance detector 58 communicates directly with the ECM 40 using the J1708 and the J1939. In another embodiment of the present invention, the distance detector 58 communicates in series via an RS232 connection that is first transformed into J1708 and then into a CAN protocol to communicate with the TCM 42 which then communicates with the ECM 40 via a CAN transformer. / J1708 and a message protocol J1922. In this way, the present invention is based on an exchange of command and information of the independent status of the specific path of the data and, in some cases, the message protocol used in the exchange of information. The ECM 40, the TCN 42 and the collision danger warning system 58 contain logic control rules that can be implemented in different combinations of circuit components of the devices and microprocessors to perform the control of the different systems and subsystems in the vehicle. Often, the control functions are logically separate and have specific input parameters, control equations and output parameters that may be unique in their genre or equally applicable in other logic control functions and / or in other motor systems or subsystems. The cruise control functions (whether smart or traditional) are schematically represented by the cruise control block 70 within the ECM 40 and represent the particular logic rules used to perform these functions. Similarly, in a preferred embodiment, the collision hazard warning system 58 includes a cruise control block that represents the logic rules necessary to implement intelligent cruise control functions. It must be taken into account that the present invention does not have the need to be used with a cruise control system of a certain type that may automatically decelerate the vehicle or not. However, the accuracy of the intended collision, using the present attempt, will be improved if the collision warning system is aware of other systems or subsystems that could provide additional capacity for automatic deceleration without requiring the intervention of the driver. This information is provided by the status messages defined in SAE J1587, which indicate the existence of different equipment spaces in the vehicle. With reference to Figure 2, a step diagram illustrating the system and the collision hazard warning method according to the present attempt is shown. It should be noted that the step diagram presented in Figure 2 which describes the present invention represents a sequential processing of the method steps, but different processing strategies may be used without departing from the spirit or scope of the present invention. For example, if the command logic is implemented in the devices, many of the steps of the method may be performed simultaneously or almost simultaneously. Similarly, in a preferred embodiment an interrupted driving processing strategy is used to obtain the objects and advantages of the present invention. A person moderately skilled in the art will understand that the concepts of the present attempt can obviously be extended to a corresponding parallel implementation without departing from the spirit or scope of the present invention. Similarly, a sequential / parallel combined implementation, using devices and / or programs to realize one or more objectives or advantages of the present invention, would be within the scope of the present invention. The control and calculation steps illustrated in Figure 2 are preferably performed by the control logic within the collision danger warning system 58 illustrated in Figure 1. However, the present invention is independent of the specific location of the logic of command as long as the appropriate information is communicated to the corresponding systems and subsystems of the vehicle or from them. The inter-vehicular distance between the host vehicle and at least one front vehicle is determined in block 100. In a preferred embodiment, this information is provided using a commercially available detector. Preferably the detector also determines the approach speed between the host vehicle and each targeted vehicle or front object. However, the information about the distance between the vehicles is easily obtained by integrating information about the relative speed or approach speed. Block 102 of Figure 2 determines the current path load of the vehicle. The route load represents the difference between the driving force needed to maintain the current speed of the vehicle on the route. Thus, the path load represents a number of force acting on the vehicle in the direction of movement (longitudinal or direction x), which are both internal and also external to the vehicle. For example, the road load incorporates external forces, such as the force of gravity when rising or falling in a decline and aerodynamic drag, in addition to internal forces, such as the friction forces of the engine and the transmission of the vehicle. The determination of the road load of the vehicle begins with the second law of Newton on the movement applied to the longitudinal direction: eF = max (1) where the forces acting on the vehicle include the driving force against which the combined forces represented by the road load resist. The driving force can be calculated using the information provided by the ECM that includes the maximum torque provided by the engine and the current percentage of maximum torque that is obtained according to: TqE =% TqDel * TqPeak (2) where TqE represents the motor torque provided by the motor. This value is used to calculate the torque supplied to the vehicle wheels according to: Tqw = TqE * RatioTrans * RatioAxle (3) where RatioTrans represents the current transmission gear ratio and RatioAxle represents the axis ratio. Alternatively, equation (3) could be represented as: Forive = TqE * ES * _ p (4) RS 44 where ES represents the engine speed in rpm and RS represents the en route speed in mph, as determined by the ECM and is issued according to SAE J1587. The radius of the vehicle covers is incorporated in the vehicle speed measured in mph by the ECM. When applying equation (1) we obtain: F - m * ax - FDrlve - FRoad (5) and solving for FRoad we obtain: FRoad - FDrive - m * ax (6) - FDrive - w * dv g dt - FDrive - μw * dv g dt where g represents the acceleration due to gravity, represents the weight of the vehicle, dv / dt represents the speed of change in time of the vehicle speed, and μw represents the average value or the expected value for the combined total weight of the vehicle (GCW). Various methods can be used to provide an estimated GCW, such as those described in US Pat. Nos. 5,335,566 and 5,272,939, the disclosures of which are hereby incorporated by reference in their entirety. The current value determined for FRoad can be used to predict the probability of a collision. However, since the route load can change between the moment when the front vehicle has just entered the vision of the warning system of the collision hazard and the moment of a potential collision, it is desirable to forecast the route load at the estimated time of the collision as represented by block 104. Various techniques can be used to predict the future value of the route load based on a predetermined number of previous values of the route load. In a preferred embodiment, the Newton divided difference technique is used to extrapolate a future value of the path load from previous load values, as illustrated in Figure 3 and explained in detail below. Block 106 determines the deceleration capacity of the vehicle based on the predicted route load determined in block 104. This determination presumes that the fuel will be removed from the engine so that the driving force FDrive will be zero. The block 106 may incorporate a further deceleration capability, provided by an engine brake, a reduction gear speed of an automatic transmission, or an automatic service brake application. However, block 106 does not include a deceleration capability of the vehicle systems or subsystems that would require the intervention of an operator, such as the manual application of the service brakes. The deceleration capacity due to the fuel removal and the expected route load is determined according to: aDefuel ~ Eürive - - - F_Road (fUtUra) _m (7) -F ,,, .. (future) μw g where aDefuel represents the Deceleration capacity due to the removal of fuel from the engine, and FRoad (future) represents the expected road load. The total deceleration capacity of the vehicle is then obtained by adding the deceleration capacity of each of the available systems or subsystems of the vehicle that are automatically activated according to: aTotal = ea (8) = aDefuel + aTrans + aRetard + aBrake + aMisc where aTotal represents the total deceleration capacity of the vehicle, aRetard represents the available deceleration given by an engine retarder, aBrake represents the deceleration available given by the service brakes actuated automatically, and aMisc represents other optional equipment elements of the vehicle that could provide an additional deceleration. Block 108 of Figure 2 then uses the total deceleration capacity to determine the possibility of a collision by substituting the values in the basic distance equation: X (t) = X0 + t (9) X0 + tv - l / 2t2aTotal where X0 represents the distance between the vehicles and v represents the approach speed between a front vehicle and the host vehicle. If the result of equation (9) is negative, a possible collision is signaled and block 110 warns the operator by means of a sumer, a light or the like. Of course, a safety factor (threshold), such as an alarm triggered by block 110, can be used if the result of equation (9) is below a predetermined threshold. With reference to Figure 3, a graph illustrating a technique for predicting future route loading according to the present invention is shown. The graph in Figure 3 marks the path load as a function of time t and distance x. The points 120 and 122 with coordinates (X0, Y0) and (XI, Yl) represent previously calculated and stored values for the route load at times tO and ti respectively. The point 124 with the coordinates (X2, Y2) corresponds to the current path load at time t2. The curve that crosses the points is represented by P (x). Point 126 represents the predicted value of P (x) at a future time t3 in which it is expected that the distance between the vehicles will be zero, i.e. the point of collision. The future value of the route load may then be determined based on a predetermined number of previous values of the route load applying any of the various extrapolation or prediction techniques. The specific technique and the number of previous values of the route load used to forecast the future value of the route load will depend on the specific application. In a preferred embodiment, the Newton divided difference technique is used with three (3) path load values to determine a path load value according to: P (x) = A0 + AX (X-X0) + A ^ XX (10) where: A0 = Y0 The predicted value is then used to determine the projected deceleration capacity of the vehicle at the time of the predicted collision. Of course it will be understood that the forms of the invention shown and described herein includes the best mode contemplated for carrying out the present invention, but that this is not given to illustrate all possible forms thereof. It will also be understood that the words used are descriptive rather than limiting and that various changes may be made without departing from the spirit or scope of the invention, as claimed below.

Claims (17)

1. R E I V I ND I C A N I N S 1. A warning system for a possible collision, the system comprising: a detector to determine an inter-vehicle distance between the vehicle and a front vehicle; a command logic in communication with the detector to indicate a potential collision based on a position value that is a function of a predicted route load value, the vehicle path load value being predicted for an estimated time of a future collision . The system of claim 1, wherein the command logic operates to predict a vehicle path load value based on a predetermined number of previously determined path load values. The system of claim 1, wherein the control logic operates to predict a vehicle load value based on a predetermined number of previously determined route load values using a split difference technique. The system of claim 1, wherein the detector determines a speed of approach between the vehicle and the front vehicle and the control logic indicates a potential collision based on a position value that is a function of distance, speed of the approach and the predicted value of the vehicle's road load. 5. The system of claim 4, in which the control logic determines the value of the position according to: x (t) = X0 + tv - l / 2t2aTotal (12) where t represents the time in seconds, X0 represents the distance, and represents the approach speed and aTotal represents the approach capability of the vehicle based on the predicted value of the vehicle's road load. The system of claim 5, wherein the vehicle includes a motor retarder characterized by a first deceleration capability and an automated transmission characterized by a second deceleration capability and in which aTotal includes the first and second deceleration capabilities. . 7. A warning system for a potential collision of a vehicle, the system comprising: a detector for determining a distance and the speed of approach in relation to at least one front object; and a command logic in communication with the detector to determine the current value of the vehicle's route load, forecasting a future value of the vehicle's route charge based on a predetermined number of previously determined current route charges, calculating the capacity Future deceleration of the vehicle using the predicted route load, and forecasting a collision based on a position value that is a function of distance, approach speed and future deceleration capability. The system of claim 7 further comprising: an alarm in communication with the command logic; and in which the control logic further functions to communicate an alarm signal with the alarm when the value of the position is below a predetermined threshold value. The system of claim 7, wherein the vehicle includes a motor and at least one cover and in which the control logic determines the current value of the vehicle's path load by subtracting a product from the mass of the vehicle and the en-route speed of the vehicle, of the driving force of the vehicle delivered from the engine to at least one tire. 10. The system of claim 9, wherein the driving force is determined according to: Tqw-TqE * ES * r_ (13) RS 44 where% Tq represents the current percentage of the maximum torque of the motor. TqPeak represents the maximum torque of the engine, ES represents the engine speed in rpm, and RS represents the vehicle speed in mph. 11. A method of warning of a possible collision of a vehicle having a detector to determine an interobject distance, comprising the method; detect the interobject distance in relation to at least one front object; determine an approach speed based on the interobject distance; determine the value of the road load based on the difference between the driving force of the vehicle and a product of the mass of the vehicle and the acceleration; determine the value of the position based on the interobject distance, the approach speed and the value of the vehicle's path load, and indicate a potential collision when the value of the position is below a predetermined threshold value. The method of claim 11, wherein the step of determining the vehicle path load value comprises forecasting a vehicle path load value for the estimated collision moment, based on a predetermined number of values of the previously determined route load. The method of claim 11, wherein the step of determining the vehicle path load value comprises forecasting a vehicle path load value for an estimated collision moment based on a predetermined number of values of load path previously determined using a split difference technique. The method of claim 11, wherein the value of the position is determined according to: x (t) = XO + tv - l / 2t2aTotal (14) where t represents the time in seconds, XO represents the interobject distance, and represents the approach speed and aTotal represents the deceleration capacity of the vehicle based on the value of the vehicle's road load. The method of claim 14, wherein the vehicle includes a motor retarder characterized by a first deceleration capability and an automated transmission characterized by a second deceleration capability and in which aTotal includes the first and second deceleration capabilities . 16. The method of claim 11, wherein the vehicle includes a motor and at least one cover and in which the step of determining the value of the vehicle's path load comprises subtracting a product from the mass of the vehicle and of the approach speed of the driving force of the vehicle delivered from the engine to at least one cover. The method of claim 16, wherein the driving force is determined according to: Tqw-TqE * ES * tr_ (13) RS 44 where% tq represents the current percentage of the maximum torque of the motor, TqPeak represents the maximum torque of the engine, ES represents the engine speed in rpm, and RS represents the vehicle speed in mph.