Speed ​​control method for controlling a powered vehicle

Abstract

Speed ​​control method (100) for controlling a powered vehicle (10), comprising: (102) Receiving a maximum permissible speed, a minimum permissible speed and a set speed by a control (34) of the driven vehicle (10); (104) Instructing a drive system by means of the control (34) to generate an instructed axle torque in order to maintain the set speed; (102) Monitoring the current speed of the driven vehicle (10); (106) Monitoring the height of a terrain at predetermined, upcoming locations of the powered vehicle (10); (108) Determining the expected speeds of the driven vehicle (10) at each of the predetermined upcoming locations using the current speed of the driven vehicle (10) and the elevation (E) of the terrain (Trr) at the predetermined upcoming locations; Monitoring the current speed of a tracked vehicle (11), wherein the tracked vehicle (11) is driving directly in front of the driven vehicle (10); Determining the expected speeds of the tracked vehicle (11) at each of the predetermined, upcoming locations using the current speed of the tracked vehicle (11) and the elevation (E) of the terrain at the predetermined, upcoming locations; (406) Determining a plurality of pursuit times at each of the predetermined, forthcoming locations using the expected speeds of the driven vehicle (10) and the expected speeds of the pursued vehicle (11), each of the plurality of pursuit times being a time required for the driven vehicle (10) to reach the pursued vehicle (11); (408) Compare each of the multiple tracking times with a predetermined minimum time threshold; (109, 408) Determine whether at least one of the multiple tracking times is smaller than the predetermined minimum time threshold; (414) in response to the determination that at least a plurality of tracking times is less than the predetermined minimum time threshold, instructing the drive system (20) of the driven vehicle (10) by the control (34) to reduce the instructed axle torque by a torque setting to prevent each of the plurality of tracking times at each of the predetermined upcoming locations from being less than the predetermined minimum time threshold; (108) Generating a table of predicted speeds using the predicted speeds of the driven vehicle (10) at each of the predetermined, upcoming locations of the driven vehicle (10), wherein the driven vehicle (10) includes a user interface (23) configured to allow a user to set the maximum permissible speed and the minimum permissible speed; (402) Generating a table of times required by the powered vehicle (10) to reach each of the predetermined upcoming locations, using the table of expected speeds; (404) Generating a table of the times required by the tracked vehicle (11) to reach each of the predetermined, upcoming locations; wherein the times required by the tracked vehicle (11) to reach each of the predetermined upcoming locations are determined using the expected speeds of the tracked vehicle (11) at each of the predetermined upcoming locations, a vehicle acceleration of the tracked vehicle (11) and an initial distance between the driven vehicle (10) and the tracked vehicle (11) at a first of the predetermined upcoming locations; Determining the speed of the tracked vehicle (11), the acceleration of the tracked vehicle (11) and the initial distance between the driven vehicle (10) and the tracked vehicle (11) at the first of the predetermined upcoming locations using one or more radars of the driven vehicle (10); Determining a difference between the times required by the driven vehicle (10) to reach each of the predetermined, imminent locations, using the table of expected speeds, and the times required by the tracked vehicle (11) to reach each of the predetermined, imminent locations, to determine each of the plurality of tracking times; in response to determining that each of the plurality of tracking times is equal to or greater than the predetermined minimum time threshold, instructing the drive system (20) of the driven vehicle (10) by the control (34) to maintain the instructed axle torque; Determining the torque setting, wherein: the predetermined minimum time threshold is equal to a minimum tracking time multiplied by a first safety factor; and the torque setting is a function of a current speed of the driven vehicle (10), a current speed of the tracked vehicle (11) and a vehicle acceleration of the driven vehicle (10) at the predetermined, upcoming locations; where the torque setting is calculated using the following equation: Δ τ az = rwm [ [ vc − vf ( xcrit ) ] [ tc − tf ( xcrit ) − β tmin ∗ ] ] − 1 x N ∑ i = 0 N − 1 ai Δ xi where: Δτ az a change in axle torque to meet a variety of auto-tracking distance conditions; v c the current speed of the driven vehicle (10) is; v f(xcrit) a speed of the pursued vehicle (11) at a distance; x crit a distance at which a violation of the predetermined minimum time threshold occurs; t c a current tracking time; t f(xcrit) a time that the tracked vehicle (11) needs to cover the distance x crit to reach; a i a vehicle acceleration of the driven vehicle (10) with index i. Δx j an incremental distance between cell i and cell i+1; r w a rolling radius of a wheel of the driven vehicle (10) in millimeters; and m is a mass of the driven vehicle (10) in kilograms; β is a second safety factor that is larger than the first safety factor to avoid a violation of the predetermined minimum time threshold; and t * min the predetermined minimum time threshold.

Description

[0001] The present description relates to a method and a system for vehicle control and, in particular, to methods and systems for vehicle control for automatically maintaining a following distance (or following time) between a driven vehicle and a followed vehicle.

[0002] The cruise control is currently calibrated to rigidly maintain the speed set by the driver and can be aggressive and inefficient when attempting to maintain the set speed during changes in road gradient. Furthermore, the cruise control algorithm is automatically deactivated during adaptive cruise control to avoid collisions with other vehicles. This results in reduced fuel consumption and unnatural behavior (e.g., aggressive up- and downshifting when driving uphill, braking on inclines, etc.).

[0003] DE 10 2016 014 935 A1 describes a technique for longitudinal control of a vehicle in a convoy of road vehicles traveling one behind the other.

[0004] It can be considered an objective to provide an alternative speed control method for a powered vehicle that optimizes fuel consumption and reduces unnatural driving behavior. This objective is achieved by the subject matter of claim 1.

[0005] To improve fuel economy, the speed control methods and systems presented here consider and synthesize elevation data and forward camera data (or radar data) to calculate upcoming trajectories for the driven vehicle and the followed vehicle (i.e., the vehicle directly in front of the driven vehicle). These trajectories are analyzed, and the vehicle's axle torque is adjusted to achieve maximum steady operation while maintaining a minimum safe following distance (or following time) to the vehicle ahead.

[0006] The speed control method according to the invention for controlling a driven vehicle comprises: receiving a set speed, a minimum permissible speed, and a maximum permissible speed by a controller of the driven vehicle; instructing a drive system by the controller to generate an instructed axle torque to maintain the set speed; monitoring a current speed of the driven vehicle; monitoring the elevation of terrain at predetermined, upcoming locations of the driven vehicle; determining the expected speeds of the driven vehicle at each of the predetermined, upcoming locations using the current speed of the driven vehicle and the elevation of the terrain at the predetermined, upcoming locations;Monitoring the current speed of a tracked vehicle, with the tracked vehicle directly in front of the driven vehicle; determining predicted speeds of the tracked vehicle at each of the predetermined upcoming locations using the current speed of the tracked vehicle and the elevation of the terrain at the predetermined upcoming locations; determining a plurality of track times at each of the predetermined upcoming locations using the predicted speeds of the driven vehicle and the predicted speeds of the tracked vehicle, each of the plurality of track times being a time required for the driven vehicle to reach the tracked vehicle; comparing each of the plurality of track times with a predetermined minimum time threshold;Determine whether at least one of the plurality of tracking times is less than the predetermined minimum time threshold; and in response to determining that at least one of the plurality of tracking times is less than the predetermined minimum time threshold, instruct the drive system of the driven vehicle by the controller to reduce the instructed axle torque by one torque setting to prevent any of the plurality of tracking times at any of the predetermined upcoming locations from being less than the predetermined minimum time threshold.

[0007] The speed control procedure further includes generating a table of predicted speeds using the predicted speeds of the driven vehicle at each of the predetermined, upcoming locations of the driven vehicle. The driven vehicle includes a user interface configured to allow a user to set the maximum and minimum permissible speeds.

[0008] The speed control procedure further includes generating a table of times required by the driven vehicle to reach each of the predetermined, upcoming locations, using the table of expected speeds.

[0009] The speed control procedure further includes generating a table of the times the tracked vehicle needs to reach each of the predetermined, upcoming locations.

[0010] The times required for the tracked vehicle to reach each of the predetermined upcoming locations are determined using the projected speeds of the tracked vehicle at each of the predetermined upcoming locations, a vehicle acceleration of the tracked vehicle, and an initial distance between the driven vehicle and the tracked vehicle at a first of the predetermined upcoming locations.

[0011] The speed control procedure further includes determining the speed of the tracked vehicle, the acceleration of the tracked vehicle, and the initial distance between the driven vehicle and the tracked vehicle at the first of the predetermined, upcoming locations using one or more radars of the driven vehicle.

[0012] The speed control procedure further includes determining a difference between the times required by the driven vehicle to reach each of the predetermined, upcoming locations, using the table of expected speeds, and the times required by the tracked vehicle to reach each of the predetermined, upcoming locations, in order to determine each of the multiple tracking times.

[0013] The speed control procedure further includes, in response to the determination that each of the multitude of tracking times is equal to or greater than the predetermined minimum time threshold, instructing the drive system of the driven vehicle by the control to maintain the commanded axle torque.

[0014] The speed control procedure further includes determining the torque setting. The predetermined minimum time threshold is equal to the minimum tracking time multiplied by a first safety factor. The torque setting is a function of the current speed of the driven vehicle, the current speed of the tracked vehicle, and the acceleration of the driven vehicle at the predetermined, upcoming locations.

[0015] The torque setting is calculated using the following equation: Δτaz=rwm[[vc−vf(xcrit)][tc+tf(xcrit)−βtmin*]]−1xN∑i=0N−1aiΔ xi where: Δτ az a change in axle torque to meet a variety of auto-tracking distance conditions; v c the current speed of the driven vehicle; v f(xkrit) a speed of the tracked vehicle at a distance x krit is; x krit a distance at which a violation of the predetermined minimum time threshold occurs; t c a current tracking time; t f(xkrift) a time that the tracked vehicle needs to cover the distance x krit to reach; a i a vehicle acceleration of the driven vehicle with index i. Δx i an incremental distance between cell i and cell i+1; r wa rolling radius of a wheel of the driven vehicle in millimeters; and m is the mass of the driven vehicle in kilograms; β is a second safety factor that is larger than the first safety factor to avoid a violation of the predetermined minimum time threshold; and tmin* the predetermined minimum time threshold.

[0016] The vehicle system according to the invention comprises a drive system and a control unit that communicates with the drive system. The control unit is programmed to execute the method described above.

[0017] The above features and advantages, as well as other features and advantages of the present teachings, are readily apparent from the following detailed description of some of the best modes and other embodiments for carrying out the present teaching, as defined in the attached claims, when considered in conjunction with the attached drawings. Fig. Figure 1 is a schematic block diagram of a vehicle. Fig. Figure 2 is a schematic representation of part of a user interface of the vehicle. Fig. 1. Fig. Figure 3 is a schematic representation of an elevation forecast table, which shows the elevation of the terrain at the predetermined, upcoming locations of the vehicle system. Fig. Figure 4 is a schematic representation of a table of expected speeds, which includes the expected speeds of the vehicle system at each of the predetermined, upcoming locations of the vehicle system. Fig. Figure 5 is a schematic representation of an updated table of expected speeds. Fig. Figure 6 is a schematic representation of a tracking time table. Fig. Figure 7 is a schematic representation of an updated tracking time table. Fig. Figure 8 is a flowchart of a procedure for controlling the speed control of the vehicle system of Fig. 1. To optimize fuel consumption. Fig. 8A is a first part of an acceleration control process of the method of Fig. 6. Fig. 8B is a second part of the acceleration control process of the procedure of Fig. 8. Fig. 8C is a third part of the acceleration control process of the procedure by Fig. 8. Fig. 9A is a first part of a delay control process of the procedure of Fig. 8. Fig. 9B is a second part of the delay control process of the procedure of Fig. 8. Fig. 9C is a third part of the delay control process of the procedure of Fig. 8. Fig. 9D is a fourth part of the delay control process of the procedure by Fig. 8. Fig. 10A is a first part of an advance control process of the procedure of Fig. 8. Fig. 10B is the second part of a forward control process of the procedure of Fig. 8.

[0018] As used herein, the term “module” refers to hardware, software, firmware, electronic control component, processing logic and / or processor device, individually or in combination, including but not limited to: an application-specific integrated circuit (ASIC), an electronic circuit, a processor (common, dedicated or grouped) and memory executing one or more software or firmware programs, a combinational logic circuit and / or other suitable components providing the described functionality.

[0019] Embodiments of the present disclosure can be described here in the form of functional and / or logical block components and various processing steps. It should be noted that such block components can be implemented by a number of hardware, software, and / or firmware components configured to perform the specified functions. For example, an embodiment of the present disclosure may employ various integrated circuit components, such as memory elements, digital signal processing elements, logic elements, lookup tables, or the like, which can perform a variety of functions under the control of one or more microprocessors or other controllers.Furthermore, the person skilled in the art will recognize that embodiments of the present disclosure can be practiced in connection with a number of systems, and that the systems described here are merely exemplary embodiments of the present disclosure.

[0020] For the sake of brevity, techniques relating to signal processing, data fusion, signaling, control, and other functional aspects of the systems (and the individual operating components of the systems) are not described in detail here. Furthermore, the connecting lines shown in the various figures included herein are intended to represent exemplary functional relationships and / or physical couplings between the various elements. It should be noted that alternative or additional functional relationships or physical connections may exist in an embodiment of this disclosure.

[0021] As in Fig. As shown in Figure 1, a driven vehicle 10 generally comprises a chassis 12, a body 14, front and rear wheels 17, and can be referred to as the host vehicle. The vehicle 10 can be referred to as a motor vehicle. The body 14 is mounted on the chassis 12 and essentially encloses components of the vehicle 10. The body 14 and the chassis 12 can together form a frame. The wheels 17 are each rotatably coupled to the chassis 12 near a corner of the body 14.

[0022] The powered vehicle 10 can be an autonomous vehicle, and a control system 89 is integrated into the powered vehicle 10. The control system 89 can alternatively also be referred to as the vehicle system. The powered vehicle 10 is, for example, a vehicle that is automatically controlled to transport passengers from one place to another. In the embodiment shown, the powered vehicle 10 is depicted as a passenger car, but it should be understood that other vehicles, including motorcycles, trucks, all-terrain vehicles (SUVs), recreational vehicles (RVs), watercraft, aircraft, etc., can also be used. The vehicle 10 can be a so-called Level Four or Level Five automation system.A Level Four system signifies a "high degree of automation" and involves the driving-mode-specific execution of aspects of the dynamic driving task by an automated driving system, even if a human driver does not respond appropriately to an intervention request. A Level Five system signifies "full automation" and involves the complete execution of aspects of the dynamic driving task by an automated driving system under various road and environmental conditions that a human driver could handle.

[0023] The powered vehicle 10 generally comprises a drive system 20, a transmission system 22, a steering system 24, a braking system 26, a sensor system 28, an actuator system 30, at least one data storage device 32, at least one control unit 34, and a communication system 36. The drive system 20 may include an electric machine, such as a drive motor and / or a fuel cell drive. The powered vehicle 10 further comprises a battery (or battery pack) 21, which is electrically connected to the drive system 20. Accordingly, the battery 21 is configured to store electrical energy and supply electrical energy to the drive system 20. Additionally, the drive system 20 may include an internal combustion engine 33 with a plurality of cylinders. If the drive system 20 employs active fuel management (AFM), not all cylinders of the internal combustion engine 33 are active.Conversely, all cylinders of the internal combustion engine 33 are active when the drive system switches off the AFM. The transmission system 22 is configured to transmit power from the drive system 20 to the vehicle wheels 17 according to selectable gear ratios. The transmission system 22 may include a stepped automatic transmission, a continuously variable transmission, or another suitable transmission. The braking system 26 is configured to transmit braking torque to the vehicle wheels 17. The braking system 26 may include friction brakes, brake-by-wire, a regenerative braking system such as an electric machine, and / or other suitable braking systems. The steering system 24 influences the position of the vehicle wheels 17. Although shown with a steering wheel for illustrative purposes, the steering system 24 may not include a steering wheel. The vehicle 10 may include an air conditioning system 29 with a compressor 31 coupled to the internal combustion engine 33 of the drive system 20.The compressor 31 can be driven by the internal combustion engine 33.

[0024] The sensor system 28 comprises one or more sensing devices 40 that detect observable conditions of the external environment and / or the internal environment of the vehicle 10. The sensor devices 40 may include, but are not limited to, radars, lidar, global positioning systems, optical cameras (e.g., forward-facing cameras), thermal cameras, ultrasonic sensors, clocks for timekeeping, and / or other sensors. The actuator system 30 comprises, but is not limited to, one or more actuator devices 42 that control one or more vehicle functions, such as the drive system 20, the transmission system 22, the steering system 24, and the braking system 26. In various embodiments, the vehicle features may further include internal and / or external vehicle features, such as doors, a trunk, and cabin features such as air conditioning, music, lighting, etc. (not numbered).The sensor system 28 comprises one or more GPS transmitter-receivers 40g (Global Positioning System) configured to acquire and monitor route data (i.e., route information). The GPS transmitter-receiver 40g is configured to communicate with a GPS to locate the position of the vehicle 10 on the globe. The GPS transmitter-receiver 40g is in electronic communication with the controller 34.

[0025] The data storage device 32 stores data for use in the automatic control of the vehicle 10. In various embodiments, the data storage device 32 stores defined maps of the navigable environment. In various embodiments, the defined maps can be predefined by and obtained from a remote system. For example, the defined maps can be compiled by the remote system and transmitted to the vehicle 10 (wirelessly and / or via a wired connection) and stored in the data storage device 32. As can be seen, the data storage device 32 can be part of the controller 34, separate from the controller 34, or part of the controller 34 and part of a separate system.

[0026] The controller 34 comprises at least one processor 44 and a non-transient readable storage device or medium 46. The processor 44 can be a custom processor, a central processing unit (CPU), a graphics processing unit (GPU), an auxiliary processor among several processors associated with the controller 34, a semiconductor-based microprocessor (in the form of a microchip or chipset), a macroprocessor, a combination thereof, or generally, an instruction-executing device. The computer-readable storage device or medium 46 can include volatile and non-volatile memory, such as read-only memory (ROM), random-access memory (RAM), and keep-alive memory (KAM). KAM is persistent or non-volatile memory that can be used to store various operating variables while the processor 44 is powered off.The computer-readable storage device or computer-readable storage media 46 can be implemented using a variety of storage devices, such as PROMs (programmable read-only memory), EPROMs (electrically erasable PROMs), EEPROMs (electrically erasable PROMs), flash memory, or other electrical, magnetic, optical, or combined storage devices capable of storing data, some of which constitute executable instructions used by the controller 34 in controlling the vehicle 10. The data storage device 32 and / or the computer-readable storage device or media 46 may contain a map database 35. In the present disclosure, the term "map database" means a database that stores geographic and topographic data, such as...Streets, paths, cities, parks, traffic signs, elevation information, a two-dimensional or three-dimensional arrangement of an object with features relating to location and category. The map database 35 contains data on the elevation E of a terrain Trr (Figs. 3, 6 and 7) at predetermined, upcoming locations of the vehicle 10. The data on the elevation E of a terrain Trr (. Fig. 3) The predetermined, upcoming locations of the vehicle 10 are hereby referred to as upcoming elevation data ED. In the present disclosure, terrain Trr is the terrain Trr in which the vehicle 10 is or will be traveling. The map database 35 can alternatively also be referred to as the map module.

[0027] The instructions can comprise one or more separate programs, each containing an ordered list of executable instructions for implementing logical functions. When executed by the processor 44, the instructions receive and process signals from the sensor system 28, perform logic, calculations, procedures, and / or algorithms for the automatic control of the vehicle 10's components, and generate control signals for the actuator system 30 to automatically control the vehicle 10's components based on the logic, calculations, procedures, and / or algorithms. Although in Fig. Figure 1 shows a single controller 34. Embodiments of the vehicle 10 may include a number of controllers 34 that communicate via a suitable communication medium or a combination of communication media and that cooperate to process the sensor signals, perform logic, calculations, procedures and / or algorithms and generate control signals to automatically control features of the vehicle 10.

[0028] In various embodiments, one or more instructions from the controller 34 are embodied in the control system 89. The vehicle 10 includes a user interface 23, which may be a touchscreen in the dashboard. The user interface 23 communicates electronically with the controller 34 and is configured to receive input from a user (e.g., the driver). Accordingly, the controller 34 is configured to receive user input via the user interface 23. The user interface 23 includes a display configured to show information to the user (e.g., the vehicle operator or passenger).

[0029] The communication system 36 is configured to wirelessly transmit information to and from other units 48, such as, but not limited to, other vehicles (“V2V” communication), infrastructure (“V21” communication), remote systems and / or personal devices (described in more detail in relation to Fig. 2) The tracked vehicle 11 can transmit relevant information (e.g., speed, acceleration, and / or location of the tracked vehicle 11) to the driven vehicle via V2V communication. In one exemplary embodiment, the communication system 36 is a wireless communication system configured to communicate via a wireless local area network (WLAN) using IEEE 802.11 standards or using mobile data communication. However, additional or alternative communication methods, such as a dedicated short-range communication channel (DSRC channel), are also considered within the scope of this disclosure. DSRC channels refer to one-way or two-way short- to medium-range wireless communication channels specifically designed for use in motor vehicles, as well as a corresponding set of protocols and standards.Accordingly, the communication system 36 can include one or more antennas and / or transmitter-receivers for receiving and / or sending signals, such as Cooperative Sensing Messages (CSMs).

[0030] Fig. Figure 1 is a schematic block diagram of the control system 89, which is configured to control the driven vehicle 10. The controller 34 of the control system 89 is in electronic communication with the brake system 26, the drive system 20, and the sensor system 28. The brake system 26 comprises one or more brake actuators (e.g., brake calipers) coupled to one or more wheels 17. When actuated, the brake actuators of the brake system 26 exert brake pressure on one or more wheels 17 to decelerate the driven vehicle 10. The drive system 20 comprises one or more drive actuators for controlling the drive of the driven vehicle 10. For example, as discussed above, the drive system 20 may include an internal combustion engine 33, and in this case, the drive actuator of the drive system 20 may be a throttle specifically configured to control the airflow in the internal combustion engine 33. The sensor devices 40 (i.e.,The sensors of the sensor system 28 may include one or more accelerometers (or one or more gyroscopes) coupled to one or more wheels 17. The accelerometer communicates electronically with the controller 34 and is configured to measure and monitor the longitudinal and lateral accelerations of the driven vehicle 10. The sensor system 28 may include one or more speed sensors 40s configured to measure and monitor the speed (or rotational speed) of the driven vehicle 10. The speed sensor 40s is coupled to the controller 34 and communicates electronically with one or more wheels 17. The sensor systems 28 may include one or more radars and / or forward-facing cameras to measure the distance between the driven vehicle 10 and a tracked vehicle 11.Thus, the sensor devices can be radars and / or forward-facing cameras. The radars and / or forward-facing cameras can also be used to determine the speed and / or acceleration of the tracked vehicle 11. In the present disclosure, the tracked vehicle 11 is a vehicle located directly in front of the driven vehicle. Consequently, no other vehicle is located between the driven vehicle 10 and the tracked vehicle 11. Accordingly, the controller 34 is programmed to monitor the speed and / or acceleration of the driven vehicle 10 based on the inputs from the sensor system 28. Furthermore, the controller 34 is programmed to monitor and determine the speed and / or acceleration of the tracked vehicle 11 based on the inputs from the sensor system 28.In addition, the control unit 34 is programmed to monitor and determine the distance between the driven vehicle 10 and the tracked vehicle 11 based on the input from the sensor system 28.

[0031] Fig. Figure 2 is a schematic representation of part of the user interface 23. The vehicle 10 has a cruise control, and the speed 25 set by the driver (shown in the user interface 23) can be adjusted by the driver, for example, using up / down arrows on the steering wheel of the vehicle 10. In addition to the driver-set speed 25, the user interface 23 also displays the speed tolerance 27, which includes a maximum permissible speed and a minimum permissible speed. The driver can set the maximum permissible speed and / or the minimum permissible speed of the speed tolerance via the user interface 23. The user interface 23 displays the permissible speed range 37, which is calculated as a function of the set speed, the maximum permissible speed, and the minimum permissible speed.The maximum permissible speed and the minimum permissible speed are each a speed limit of a permissible speed range 37.

[0032] With reference to Fig. 3 describes in the present disclosure a speed control method 100 ( Fig. 6) uses the upcoming elevation data ED to understand in advance when continuous speed control operation will result in speed violation (drifting outside the driver's limits). The driven vehicle 10 can then prepare for the impending violation and will adjust the torque command at opportunistic (efficient) times using this understanding of the upcoming terrain Trr. To this end, the controller 34 receives and monitors the elevation data ED about the upcoming terrain Trr from the map database 35 and / or vehicle sensors / cameras (e.g., a sensor system 28). As described above, the data about the elevation E of a terrain Trr ( Fig. 3) at predetermined, upcoming locations of the vehicle 10, here referred to as upcoming elevation data ED. Using this upcoming elevation data, the controller 34 then generates an elevation preview table. The elevation preview table EDT contains a multitude of preview elevation points. The preview elevation points are equidistant from each other. In other words, the preview points are separated from each other by a predetermined distance, and the first preview point is separated from the current location of the driven vehicle 10 by the same predetermined distance.

[0033] With reference to Fig. 4 determines (i.e., calculates) the controller 34 a predicted speed of the driven vehicle 10 at each foresight peak. In other words, the controller 34 is programmed to determine the predicted speeds of the driven vehicle 10 at each of the predetermined, upcoming locations of the driven vehicle 10 as a function of the current speed of the driven vehicle 10 and the elevation E of the terrain Trr at the predetermined, upcoming locations of the driven vehicle 10. Then, the controller 34 generates a table of predicted speeds PST using the predicted speeds PS of the vehicle 10 at each of the predetermined, upcoming locations of the driven vehicle 10. Next, the controller 34 determines whether there is a speed overrun V.In other words, the control 34 determines whether one or more of the expected speeds are outside the permissible speed range 37 (. Fig. 2).

[0034] With reference to Fig. 5 After identifying a speed violation V, the control unit 34 calculates the necessary increase in an initial torque to compensate for the change in altitude, which leads to compliance with the permissible speed range 37 ( Fig. 2) Increasing the calculated axle torque results in a new predicted speed profile for the same gradient, thus ensuring compliance with the permissible speed deviation. In other words, the controller 34 generates an updated UPST predicted speed table based on the increased calculated axle torque, as detailed below.

[0035] With reference to Fig. 6, as discussed below, includes the speed control procedure 100 ( Fig. 8) Determining the tracking time (in seconds) between the driven vehicle 10 and the tracked vehicle 11 at each predetermined, upcoming location. The controller 34 then generates a tracking time table (FTT). In the present disclosure, the term "tracking time" means the time required for the driven vehicle 10 to reach and make contact with the tracked vehicle 11. As described above, with a clear track, the tracked vehicle 11 is directly in front of the driven vehicle 10, and no other vehicle is located between the driven vehicle 10 and the tracked vehicle 11. The tracking time table (FTT) contains the tracking times (in seconds) at each predetermined, upcoming location. The predetermined, upcoming locations can be defined as a distance x. iThese are designated as predetermined, upcoming locations (i.e., the distance x). i ) correspond to the predetermined, upcoming locations in the tables in Figs. 3, 4 and 5. The tracking times at the predetermined, upcoming locations should be less than a predetermined minimum time threshold to prevent the driven vehicle 10 from coming into contact with the tracked vehicle 11.

[0036] With continued reference to Fig. 6. The controller 34 generates a first distance table FDT to create the tracking time table FTT. The first distance table FDT contains the time the driven vehicle 10 needs to reach each predetermined, upcoming location (i.e., distance x). i ) to reach. The time required by the powered vehicle 10 to reach each predetermined, upcoming location can be determined using the table of expected speeds PST ( Fig. 4) or the updated UPST estimated speeds table ( Fig. 5) are calculated when the assigned axle torque has been set. The controller 34 also generates a second distance table SDT. The second distance table SDT contains the time the tracked vehicle 11 needs to reach each predetermined, upcoming location (i.e., distance x). iTo this end, the controller 34 can determine the current speed and acceleration of the tracked vehicle 11 using the sensor devices 40 (e.g., forward-facing camera and / or radar) and / or information transmitted from the tracked vehicle 11 to the driven vehicle 10 via V2V communication. Using the current speed and acceleration of the tracked vehicle 11, the controller 34 determines the predicted speeds of the tracked vehicle 11 at each predetermined, upcoming location (i.e., distance x). i Then, using the expected speeds of the tracked vehicle 11, the controller 34 determines the target speed at each predetermined, upcoming location (i.e., distance x). i), the acceleration of the tracked vehicle 11 and the initial tracking distance from the driven vehicle 10 to the tracked vehicle 11, the time the tracked vehicle 11 needs to reach each predetermined, upcoming location (i.e., distance x) i ) to achieve this, and generates the second distance table SDT.

[0037] With continued reference to Fig. Control 34 then calculates the distance for all points in the first distance table FDT and the second distance table SDT where the distance x iThe controller 34 reads the tracking time table FTT to identify a tracking time violation FTV. A tracking time violation FTV occurs only if any of the tracking times at the predetermined upcoming location is less than a predetermined calibratable distance.The predetermined minimum time threshold may be, for example, 0.8 seconds, and the controller 34 can only detect a tracking time violation (FTV) if one or more of the tracking times in the tracking time table (FTT) are less than 0.8 seconds.

[0038] With reference to Fig. 7. In response to the determination that at least one plurality of tracking times is less than the predetermined minimum time threshold, the controller 34 instructs the drive system 20 of the driven vehicle 10 to reduce the instructed axle torque by adjusting the torque to prevent any of the plurality of tracking times at any of the predetermined upcoming locations from being less than the predetermined minimum time threshold. The controller 34 then generates an updated first distance table UFDT, an updated second distance table USDT, and a UFTT to determine if any of the updated tracking times is less than the predetermined minimum time threshold.

[0039] Fig. Figure 8 is a flowchart of a speed control procedure 100 for controlling the speed control of the driven vehicle 10 of Fig. 1. To optimize fuel consumption. Procedure 100 begins in block 102. In block 102, the controller 34 determines that the speed control has been activated by the driver of the driven vehicle 10. The driver can turn on the speed control via the user interface 23. For example, the driver can press a button on the user interface 23 to activate the speed control. In block 102, the driver can also change the set speed v. ss , the maximum permissible speed v max and the minimum permissible speed v min The user can set the speed via the user interface 23, for example by pressing the up / down arrows on the steering wheel of the vehicle 10. The controller 34 in block 102 then receives the set speed v. ss , the maximum permissible speed v max and the minimum permissible speed v minfrom the user interface 23. As described above, each of the maximum permissible speeds v max and the minimum permissible speed v min a speed limit of the permissible speed range 37. In block 102, the controller 34 also determines and monitors (in real time) the current vehicle speed v based on the inputs from the speed sensor 40s. After block 102, the procedure 100 continues with block 104.

[0040] In block 104, the control unit 34 sets the assigned axis torque τ. ss on the road load torque at the set speed v ss one. For this purpose, the control unit 34 instructs the drive system 20 to apply the specified axle torque τ. ss to generate the set speed v ss to stop. Then procedure 100 continues with block 106.

[0041] In block 106, the control unit 34 also determines and monitors the elevation E of the terrain Trr at predetermined, upcoming locations of the vehicle 10 using the upcoming elevation data from the map database 35. Furthermore, the control unit 34 generates the elevation preview table EDT ( Fig. 3) using the elevation E of the terrain Trr at the predetermined, upcoming locations of the vehicle 10. As described above, the elevation preview table EDT contains ( Fig. 3) A multitude of preview elevation points corresponding to the predetermined, upcoming locations of the driven vehicle 10. The controller 34 uses upcoming elevation data ED from the map database 35 to generate the elevation preview table EDT. Therefore, block 106 also includes retrieving elevation data ED from the map database 35 and subsequently using the upcoming elevation data ED to generate the elevation preview table EDT. The preview elevation points in the elevation preview table EDT are equidistant from each other. In other words, the preview points are separated from each other by a predetermined distance, and the first preview point is separated from the current location of the vehicle 10 by the same predetermined distance. Then, the procedure 100 proceeds with block 108.

[0042] In block 108, the controller 34 determines the expected speeds of the vehicle at each of the predetermined, upcoming locations of the vehicle as a function of the current speed v0 of the driven vehicle 10 and the elevation E of the terrain Trr at the predetermined, upcoming locations of the driven vehicle 10. For this purpose, the controller 34 assumes that the driven vehicle 10 maintains a constant torque (i.e., the road-load torque at the set speed v). ss ) and calculates the expected velocities at each preview point in the EDT elevation table (given the elevation changes in the EDT elevation table) using the following equation: vi=2g(h0−hi)+v02 where v0 is the current speed of the vehicle 10; h0 is the current elevation of the terrain Trr at the current location of vehicle 10; h ithe height at point i in the height preview table EDT is; g is the acceleration due to gravity; and v i The expected velocity at point i in the elevation preview table EDT is...

[0043] Using the equations above, the controller 34 calculates the expected speed at each preview point and generates the table of expected speeds PST ( Fig. 4) using the expected speeds of vehicle 10 at each of the predetermined, upcoming locations of vehicle 10. After block 108, procedure 100 continues with block 109.

[0044] In block 109, the control unit 34 executes a forward control algorithm 400 ( Fig. 10A and Fig. 10B). The forward control algorithm 400 ( Fig. 10A and Fig. 10B) determines whether the tracking times (between the driven vehicle 10 and the tracked vehicle 11) at predetermined upcoming locations are less than the predetermined minimum time threshold. If any of the tracking times at the predetermined upcoming locations are less than the predetermined minimum time threshold, then procedure 100 proceeds to block 111. In block 111, the controller 34 executes the forward control algorithm 400 ( Fig. 10A and Fig. 10B) until conditions permit the resumption of the free-road algorithm. The free-road algorithm refers to speed control procedure 100, except for Block 111, and the conditions that permit its resumption are that the tracking times at the predetermined upcoming locations are equal to or greater than the predetermined minimum time threshold. Thus, if conditions permit the free-road algorithm to be resumed, procedure 100 returns to Block 104. If, in Block 109, the tracking times at the predetermined upcoming locations are equal to or greater than the predetermined minimum time threshold, then procedure 100 proceeds to Block 110.

[0045] In Block 110, Control 34 compares each of the predicted speeds at each of the predetermined, upcoming locations with the permissible speed range 37 to determine if any of the predicted speeds are outside the permissible speed range 37. In other words, in Block 110, Control 34 determines if there are any predicted speeds in the table of predicted speeds PST ( Fig. 4) gives the maximum permissible speed v max and / or the minimum permissible speed v min infringe. If there are no anticipated speeds that determine the maximum permissible speed v max and / or the minimum permissible speed v min If the procedure is violated, it returns to block 104. If there are anticipated speeds that exceed the maximum permissible speed v maxIf the speed limit is violated, the controller 34 begins the deceleration control process 300 (Figs. 8A, 8B, 8C and 8D) at block 112. In the deceleration control process 300, the controller 34 instructs the drive system 20 of the vehicle 10 to adjust the instructed axle torque to maintain the actual speed of the vehicle 10 within the permissible speed range 37 at each of the predetermined, upcoming locations. After the execution of the deceleration control process, the procedure 100 returns to block 104. If there are anticipated speeds that exceed the minimum permissible speed v minIf a violation occurs, the controller 34 in block 114 begins the acceleration control process 200 (Figs. 7A, 7B and 7C). In the acceleration control process 200, the controller 34 instructs the drive system 20 of the vehicle 10 to adjust the assigned axle torque to maintain the actual speed of the vehicle 10 within the permissible speed range 37 at each of the predetermined, upcoming locations. After executing the acceleration control process, the procedure 100 returns to block 104.

[0046] Figures 8A, 8B, and 8C show the acceleration control process 200. In block 114 (as described above), the controller 34 transitions to acceleration control (i.e., it begins the acceleration control process 200). The acceleration control process 200 then transitions to block 202. In block 202, the controller 34 uses the predicted speed table (PST) to identify an initial speed point that represents the minimum allowable speed v. min violated. In other words, control 34 identifies the first speed point in the PST predicted speed table that is lower than the minimum permissible speed v. min After block 202, the acceleration control process 200 continues to block 204.

[0047] In Block 204, starting from the first speed point identified in Block 202, the control 34 progresses forward in the table of expected speeds PST until Vi+1 >v i , to find the first local minimum of the expected velocity. In the acceleration control process 200, this first local minimum of the expected velocity is referred to as v. peak The procedure continues with block 206 after block 204. The first local minimum v peak The expected speed can correspond to a local altitude maximum in the EDT altitude preview table. Therefore, the controller 34 also determines the local altitude maximum in the EDT altitude preview table and its corresponding index i. peak in the elevation preview table EDT. The acceleration control process 200 then continues with block 206.

[0048] In block 206, the control unit 34 determines and stores the distance from the current location of the vehicle 10 to the local maximum altitude and the associated index i. peak in the altitude preview table EDT. The distance from the current location of vehicle 10 to the local altitude maximum is called the peak distance d. peak The acceleration control process 200 continues from block 206 to block 208. In block 208, the controller 34 sets the desired speed at the peak spacing d. peak to the minimum permissible speed v min After block 208, the acceleration control process 200 continues with block 210.

[0049] In block 210, the controller 34 calculates a scaled table of expected speeds, such as an updated UPST expected speed table, which is in Fig. 5 is shown. The controller 34 can use the following equation for this: vi,scaled=v0+(vi+v0)[v0−vminv0−vpeak] where: v0 is the current speed of the vehicle 10; v i a predicted speed of vehicle 10 at an index point i; v min the minimum permissible speed is; v peak the first local minimum of the predicted velocity determined in block 204; and v i,scaled the scaled, predicted speed of vehicle 10 at an index point i is.

[0050] Using the equation above, the controller 34 generates a scaled table of expected speeds. The controller 34 calculates this scaled table of expected speeds based on the minimum permissible speed v. min and the first local minimum v peak After block 210, the acceleration control process 200 transitions to block 212.

[0051] In block 212, the controller 34 calculates the required work W to achieve the minimum permissible speed v. min at the peak distance d peak To achieve this, the controller 34 can use the following equation: W=M(vmin2−vpeak2)2⋅1η where: m is the mass of the vehicle 10; v spitze the first local minimum of the predicted velocity determined in block 204; η is a calibratable (and / or learned) engine-road efficiency factor; v min the minimum permissible speed is; W is the work required to reach the minimum permissible speed v min at the peak distance d peak is.

[0052] After determining the work effort W required to achieve the minimum permissible speed v min at the peak distance d peakThe acceleration control process 200 continues with block 214.

[0053] In block 214, the controller 34 calculates the set torque τ. req , which is required (if applied constantly) to achieve the minimum permissible velocity v min at the peak distance d peak to achieve this, using the following equation: τreq=W(ipeak)rw2[∑i=1ipeak(vi+1−vi)(vi+12−vi2)(xi+1−xi)(∑i=1ipeakvi)]−1 where: r w the radius of one of the wheels is 17 (i.e. the wheel radius); v i the expected speed at index point i in the scaled table of expected speeds generated in block 210; x i the distance from the current location of vehicle 10 to index point i in the scaled table of expected speeds generated in block 210 is; v i+1the expected speed at index point i+1 in the scaled table of expected speeds generated in block 210; i peak the index point (i.e., the location) at the first local minimum v peak the expected speed; i peak-1 the index point (i.e., the location) immediately before the first local minimum v peak the expected speed; and τ req The set torque is the torque required (with constant application) to maintain the minimum speed limit v defined by the driver. min to reach;

[0054] In block 214, efficiency is maximized when the required work W is supplied to the system at a constant rate. After block 214, the acceleration control process 200 transitions to block 216.

[0055] In block 216, the controller 34 recalculates the table of expected speeds, assuming that the assigned axle torque is kept constant at the sum of the set torque τ. req , which is required (if applied constantly) to achieve the minimum permissible velocity v min at the peak distance d peak to achieve, and the specified axle torque τ ss road load torque at the set speed v ss After block 216, the acceleration control process 200 moves to block 218.

[0056] In block 218, the control unit 34 determines whether there is a gap before the peak distance d. peak There are speed violations. If there are violations of the minimum speed before the top distance d peak If there is a problem, then the acceleration control process 200 returns to block 202. If there is a problem before the peak distance d peakIf there are violations of the maximum speed, then the controller 34 in block 112 begins the deceleration control process 300 (Figs. 8A, 8B, 8C and 8D). If there are no speed violations before the peak distance d peak If there is no such event, then the acceleration control process 200 continues with block 220.

[0057] In block 220, the control unit 34 sets the assigned motor torque to the sum of the set torque τ. req , which is required (if applied constantly) to achieve the minimum permissible velocity v min at the peak distance d peak to achieve, and the specified axle torque τ ss on the road load torque at the set speed v ss Furthermore, the controller 34 instructs the drive system 20 to generate an updated, instructed axis torque. This updated, instructed axis torque can be equal to the set torque τ. reqbe that which is required (if it is applied constantly) to achieve the minimum permissible speed v min at the peak distance d peak plus the specified axle torque τ ss road load torque at the set speed v ss to achieve this. Then the acceleration control process 200 continues with block 222.

[0058] Between blocks 220 and 222, vehicle 10 travels to preview point x1 in the elevation preview table EDT. In block 222, the controller 34 sets the peak spacing d. peak according to the following equation: dpeak=dpeak−dx where: d peak the gap between the leaders is; and dx is the distance between preview point x0 and preview point x1 in the elevation preview table EDT.

[0059] After block 222, the acceleration control process 200 continues with block 224. In block 224, the controller 34 determines whether the newly set peak spacing d peak is less than zero. If the newly set peak spacing d peak If the value is not less than zero, then the acceleration control process 200 returns to block 216. If the newly set peak spacing d peak If the value is less than zero, then the acceleration control process 200 transitions to block 226. In block 226, the controller 34 exits the acceleration control process.

[0060] Figures 9A, 9B, 9C, and 9D show the delay control process 300. In block 112 (as described above), the controller 34 transitions to delay control (i.e., it begins the delay control process 300). The delay control process 300 then transitions to block 302. In block 302, the controller 34 uses the predicted speed table PST to identify an initial speed point that represents the maximum allowable speed v. max violated. In other words, control 34 identifies the first speed point in the table of expected speeds PST that is greater than the maximum permissible speed v. max After block 302, the delay control process 300 continues to block 304.

[0061] In block 304, starting from the first speed point identified in block 302, the control unit 34 moves forward in the table of expected speeds PST until v i+j <v i , to find the first local maximum of the expected velocity. This first local maximum of the expected velocity is referred to as v in the deceleration control process 300. peak The procedure continues with block 306 after block 304. The first local maximum v peak The expected speed can correspond to a local altitude minimum in the altitude preview table EDT. Therefore, the controller 34 also determines the local altitude maximum in the altitude preview table EDT and the associated index i. peak in the elevation preview table EDT. Subsequently, the delay control process 300 continues with block 306.

[0062] In block 306, the control unit 34 determines and stores the distance from the current location of the vehicle 10 to the local minimum height and the associated index i. peak in the altitude forecast table EDT. The distance from the current location of the driven vehicle 10 to the local altitude minimum is called the peak distance d. peak The delay control process 300 continues to block 308 after block 304.

[0063] In block 308, the control unit 34 sets the desired speed at the peak spacing d. peak to the maximum permissible speed v max After block 308, the delay control process 300 continues with block 310.

[0064] In block 310, the controller 34 calculates a scaled table of expected speeds, such as an updated UPST expected speed table, which is in Fig. 5 is shown. The controller 34 can use the following equation for this: vi,scaled=v0+(vi−v0)[vmax−v0vpeak−v0] where: v0 is the current speed of the vehicle 10; v i a predicted speed of vehicle 10 at an index point i; v max the maximum permissible speed is; v peak the first local maximum of the predicted velocity determined in block 304; and v i,sclaed the scaled, predicted speed of vehicle 10 at an index point i is.

[0065] Using the equation above, the controller 34 generates a scaled table of expected speeds. The controller 34 calculates this scaled table of expected speeds based on the maximum permissible speed v. max and the first local maximum v peakAfter block 310, the delay control process 300 transitions to block 312.

[0066] In block 312, the controller 34 calculates the required work W to achieve the maximum permissible speed v. max at the peak distance d peak To achieve this, the controller 34 can use the following equation: W=m(vmin2−vpeak2)2⋅1η where: m is the mass of the vehicle 10; v peak the first local maximum of the predicted velocity determined in block 304 is; η is a calibratable engine-road efficiency factor; v max the maximum permissible speed is; W is the work required to reach the maximum permissible speed v min at the peak distance d peak is.

[0067] After determining the work effort W required to reach the maximum permissible speed vmax at the peak distance d peak The delay control process 300 continues with block 314.

[0068] In block 314, the controller 34 calculates the set reduction of the torque τ. req , which is required (if applied constantly) to achieve the maximum permissible speed v max at the peak distance d peak to achieve this, using the following equation: τreq=W(ipeak)rw2[∑i=1ipeak−1(vi+1−vi)(vi+12−vi2)(xi+1−xi)(∑i=1ipeakvi)]−1 where: r w the radius of one of the wheels is 17 (i.e. the wheel radius); v i the expected speed at index point i in the scaled table of expected speeds generated in block 210; x ithe distance from the current location of vehicle 10 to index point i in the scaled table of expected speeds generated in block 210 is; v i+1 the expected speed at index point i+1 in the scaled table of expected speeds generated in block 210; i Spitze the index point (i.e., the location) at the first local minimum v peak the expected speed; i peak-1 the index point (i.e., the location) immediately before the first local minimum v peak the expected speed; and τ req The set torque is the torque required (with constant application) to achieve the maximum speed limit v defined by the driver. max to reach;

[0069] In block 314, efficiency is maximized when the required work W is supplied to the system at a constant rate. After block 314, the delay control process 300 transitions to block 316.

[0070] In block 316, the controller 34 recalculates the table of expected speeds, assuming that the assigned axle torque is kept constant at the sum of the set torque reduction τ. req , which is required (if applied constantly) to achieve the maximum permissible speed v max at the peak distance d peak and the assigned axle torque τ ss road load torque at the set speed v ss to achieve this. After block 316, the delay control process 300 transitions to block 318.

[0071] In block 318, the control unit 34 determines whether there is a gap before the peak distance d. peakThere are speed violations. If there are violations of the maximum speed before the peak value d peak If there are violations of the minimum speed before the peak distance d, the delay control process 300 returns to block 302. peak If there are any, then the control unit 34 begins the acceleration control process 200 (Figs. 7A, 7B and 7C) at block 114. If there are no speed violations before the peak distance d peak If there is a delay, then the delay control process 300 moves to block 320.

[0072] In block 320, the controller 34 compares the absolute value of the set torque reduction τ. req , which is required (if applied constantly) to achieve the maximum permissible speed v max at the peak distance d peakto achieve this, with the absolute value of the torque required to operate the air conditioner 29 (i.e., the maximum generator torque). If the absolute value of the set torque reduction τ req , which is required (if applied constantly) to achieve the maximum permissible speed v max at the peak distance d peak If the set torque required to operate the air conditioner 29 is greater than the absolute value of the torque, then the delay control process 300 continues with block 322. If the absolute value of the set torque reduction τ req , which is required (if applied constantly) to achieve the maximum permissible speed v max at the peak distance d peak If the torque required for the operation of the air conditioning system 29 is not greater than the absolute value of the torque, then the delay control process 300 continues with block 324.

[0073] In block 324, the control unit 34 maintains the assigned axis torque τ. ss upright. Furthermore, the set reduction in torque τ is... req , which is required (if applied constantly) to achieve the maximum permissible speed v max at the peak distance d peak This is achieved via battery regeneration. During battery regeneration, the drive system 20 charges the vehicle's battery 21. After block 324, the deceleration control process 300 transitions to block 340.

[0074] In block 340, vehicle 10 travels to preview point x1 in the elevation preview table EDT. After block 340, the delay control process 300 transitions to block 342.

[0075] In block 342, the control unit 34 sets the peak spacing d. peak based on the following equation: dpeak=dpeak−dx where: d peak the gap between the leaders is; and dx is the distance between the preview point x0 and the preview point x1 in the elevation preview table EDT.

[0076] After block 342, the delay control process 300 continues with block 344.

[0077] In block 344, the control unit 34 determines whether the newly set peak spacing d peak is less than zero. If the newly set peak value distance d peak If the value is not less than zero, then the delay control process 300 returns to block 316. If the newly set peak spacing d peak If the value is less than zero, then the delay control process 300 continues to block 346. In block 346, the controller 34 exits the delay control.

[0078] In block 322, the controller 34 instructs the drive system 20 to initiate maximum battery regeneration. During maximum battery regeneration, the drive system 20 charges the vehicle 10's battery 21. In the second deceleration mode, the drive system 20 drives a compressor 31 of the air conditioning system 29. In block 322, the controller 34 sets the absolute value of the configured torque reduction τ. req , which (with constant application) is required to achieve the maximum permissible speed v max at the peak distance d peak to achieve an absolute value equal to the set reduction of torque τ req , which (with constant application) is required to achieve the maximum permissible speed v max at the peak distance d peak to achieve, minus the torque required to operate the air conditioning unit 29. After block 322, the delay control process 300 passes to block 326.

[0079] In block 326, the controller 34 determines whether the air conditioning unit 29 is switched on. If the air conditioning unit 29 is switched on, the delay control process 300 continues with block 328. If the air conditioning unit 29 is switched off, the delay control process 300 continues with block 330.

[0080] In block 328, the controller 34 compares the absolute value of the newly set, adjusted reduction of the torque τ. req , which is required (if applied constantly) to achieve the maximum permissible speed v max at the peak distance d peak to achieve this, with the absolute value of the torque required to operate the air conditioning system 29 (i.e., the maximum air conditioning compressor torque). The maximum air conditioning compressor torque is the maximum torque required to operate the compressor 31 of the air conditioning system 29. If the absolute value of the set torque reduction τreq , which is required (if applied constantly) to achieve the maximum permissible speed v max at the peak distance d peak If the set torque reduction τ is greater than the absolute value of the torque required to operate the air conditioner 29, then the delay control process 300 switches to block 332. req , which is required (if applied constantly) to achieve the maximum permissible speed v max at the peak distance d peak If the torque required for the operation of the air conditioning system 29 is not greater than the absolute value of the torque, then the delay control process 300 continues with block 334.

[0081] In block 332, the controller 34 sets the maximum air conditioning compressor load to maximum for the current climate settings. In block 332, the controller 34 sets the absolute value of the newly set, adjusted torque reduction τ. req , which is required (if applied constantly) to achieve the maximum permissible speed v max at the peak distance d peak to achieve, equal to the absolute value of the adjusted reduction of torque τ req , which is required (if applied constantly) to achieve the maximum permissible speed v max at the peak distance d peak to achieve, minus the maximum torque required to operate the compressor 31 of the air conditioning system 29. After block 332, the delay control process 300 continues with block 330.

[0082] In block 334, the control unit 34 maintains the assigned axis torque τ. ssupright. In addition, the set reduction of torque τ is determined via the air conditioning compressor load (i.e., the load of compressor 31 of the air conditioning system 29). req provided, which is required (if applied constantly) to achieve the maximum permissible speed v max at the peak distance d peak to achieve this. After block 334, the delay control process 300 transitions to block 340. In block 330, the controller 34 compares the absolute value of the newly set, adjusted torque reduction τ. req , which is required (if applied constantly) to achieve the maximum permissible rotational speed v max at the peak distance d peak to achieve, with the absolute value of the torque required for the operation of the air conditioning system 29. If the absolute value of the newly set, adjusted reduction of the torque τ req, which is required (if applied constantly) to achieve the maximum permissible speed v max at the peak distance d peak If the required torque for the operation of the air conditioning system 29 is greater than the absolute value of the torque, then the delay control process 300 continues with block 336. If the absolute value of the newly set, adjusted torque reduction τ req , which is required (if applied constantly) to achieve the maximum permissible speed v max at the peak distance d peak If the torque required to operate the air conditioning system 29 is not greater than the absolute value of the torque, then the delay control process 300 continues with block 338.

[0083] In block 336, the controller 34 sets the virtual pedal input to zero (fully extended). In other words, the controller 34 instructs the drive system 20 to generate zero torque. In block 336, the controller 34 instructs the brake system 26 to actuate in order to reduce the remaining assigned axle torque τ. ss to provide. After block 336, the delay control process 300 transitions to block 340.

[0084] In block 338, the control unit 34 sets the assigned motor torque to the sum of the set torque reduction τ. req , which is required (if applied constantly) to achieve the maximum permissible speed v max at the peak distance d peak to achieve, and the specified axle torque τ ss on the road load torque at the set speed v ssIn other words, the control unit 34 instructs the drive system 20 to apply the assigned axle torque to the sum of the set torque reduction τ. req , which is required (if applied constantly) to achieve the maximum permissible speed v max at the peak distance d peak to achieve, and the specified axle torque τ ss on the road load torque at the set speed v ss , to reduce. After block 338, the delay control process 300 transitions to block 340.

[0085] Figures 10A and 10B schematically show a flowchart of the forward control algorithm or process 400 of the speed control method 100 ( Fig. 8) As described above, the advance control process 400 begins in block 109. Then, the advance control process 400 moves to block 402. In block 402, the controller 34 calculates and generates a table of the times the driven vehicle 10 needs to reach each of the distance break points x0, x1, x2, etc. (i.e., the first distance table in Fig. 6) using the predicted open-road speeds (i.e., predicted speeds table PST or updated predicted speeds table UPST if the instructed axle torque has been adjusted). In other words, the controller 34 is programmed to generate a table of the times the driven vehicle 10 needs to reach each of the predetermined locations (i.e., the first distance table FDT in Fig. 6), using the predicted speed table (i.e., the predicted speed table PST or the updated predicted speed table UPST if the assigned axle torque has been adjusted). After block 402, the forward control process 400 proceeds to block 404. Alternatively, the controller 34 can execute blocks 402 and 404 concurrently to minimize the time required to execute the forward control process 400.

[0086] In block 404, the controller 34 calculates and generates a similar table for the tracked vehicle 11. Specifically, taking into account the initial tracking distance between the driven vehicle 10 and the tracked vehicle 11, the speed of the tracked vehicle 11, and the acceleration of the tracked vehicle 11, the controller 34 calculates how long the tracked vehicle 11 needs to reach the same distance breakpoints x0, x1, x2, etc. (i.e., the first distance table in Fig. 6) As described above, the controller 34 can determine the initial tracking distance between the driven vehicle 10 and the tracked vehicle 11 at the first distance break point x0 (first predetermined upcoming location), the speed of the tracked vehicle 11, and the acceleration of the tracked vehicle 11 using the sensor devices 40, such as radars or forward-facing cameras. Therefore, the controller 34 generates the second distance table SDT ( Fig. 6), which contains the times the tracked vehicle needs to reach each of the predetermined, upcoming locations. Next, the advance control process 400 moves to Block 406.

[0087] In block 406, the controller calculates 34 for all predetermined, upcoming locations in the first distance table FDT ( Fig. 6) and the second distance table SDT ( Fig. 6), where the distance x iThe difference between the time required by the driven vehicle 10 to reach each of the predetermined upcoming locations (as shown in the first distance table FDT) and the time required by the tracked vehicle 11 to reach each of the predetermined upcoming locations is used to determine each of the tracking times at each predetermined upcoming location, thus generating the tracking time table FTT. To do this, the controller 34 subtracts at each predetermined upcoming location (i.e., distance x) i ), which is smaller than the predetermined calibratable distance, the time the tracked vehicle 11 needs to cover the distance x i to achieve, from the time the driven vehicle 10 needs to travel the same distance x i to achieve the tracking times at each of the predetermined, upcoming locations (i.e., at each distance x)i to obtain. The distance x i can be considered point x i to be designated, and the time required to cover the distance x i to achieve this can be expressed as a function of time t(x) or t(x). i ). The forward control process 400 then transitions to block 408.

[0088] In block 408, control 34 determines whether any point in the array (i.e., the table) generated in block 406 is smaller than the predetermined minimum time threshold. In other words, control 34 compares the track times to the predetermined minimum time threshold to determine if at least one of the track times (calculated in block 406) is smaller than the predetermined minimum time threshold. The predetermined minimum time threshold is equal to a minimum track time t. minmultiplied by a first safety factor α. If none of the tracking times (determined in block 406) is smaller than the predetermined minimum time threshold, then the advance control process 400 transitions to block 410.

[0089] In block 410, the controller 34 instructs the drive system 20 to maintain the assigned axle torque. In other words, the controller 34 instructs the drive system 20 to maintain the assigned axle torque when it is determined that any of the detected tracking times is equal to or greater than the predetermined minimum time threshold. Following block 410, the forward control process 400 proceeds to block 412.

[0090] In block 412, control 34 exits the forward control process 400, and procedure 100 continues with block 104. In other words, in block 412, the forward control process 400 has passed its test.

[0091] Returning to Block 406: If the control system 34 determines that at least one of the tracking times is less than the predetermined minimum time threshold, then the forward control process 400 moves to Block 414.

[0092] In block 414, the controller 34 instructs the drive system 20 of the driven vehicle 10 to reduce the directed axle torque by a torque setting to prevent each of the tracking times at each of the predetermined upcoming locations from being shorter than the predetermined minimum time threshold, in response to the detection that at least one of the tracking times is shorter than the predetermined minimum time threshold. As a result, the controller 34 prevents the driven vehicle 10 from reaching the tracked vehicle 11 during speed control. Specifically, if a violation of the predetermined minimum time threshold is anticipated before a predetermined calibratable distance D, the axle torque command is reduced to prevent the driven vehicle 10 from following the tracked vehicle 11 too closely.The control unit 34 commands the drive system 20 to modify the specified axis torque so that at distance x. crit (i.e., the distance at which the injury occurs): Vveh(xcrit)=Vf(xcrit)and(t(xcrit)−tf(xcrit))=βtmin∗ where: V veh (x crit ) a speed of the driven vehicle 10 at a distance x crit (i.e., the distance at which the injury occurs); V f (x crit ) the speed of the pursued vehicle 11 at a distance x crit (i.e., the distance at which the injury occurs); t(x crit ) a tracking time of the driven vehicle 10 at a distance x crit (i.e., the distance at which the injury occurs); t f (x crit ) a pursuit time of the pursued vehicle 11 at distance xcrit (i.e. the distance at which the violation occurs); tmin∗ the predetermined minimum time threshold; and β is a second safety factor that is larger than the first safety factor α to avoid a violation of the predetermined minimum time threshold. β is a second calibratable safety factor that is larger than the first safety factor α to prevent a violation of the predetermined minimum time threshold. This ensures that the controller 34 maintains an acceptable tracking time. βtmin∗ The system aims for and adjusts the speed of the tracked vehicle 11 to this minimum tracking time. The axle torque change (i.e., the torque adjustment) required to achieve these conditions is summarized in the following relationship: τaz=rwm[[vc−vf(xcrit)][tc+tf(xcrit)−βtmin∗]]−1xN∑i=0N−1aiΔxi where: Δτ aza change in axle torque to meet a variety of auto-tracking distance conditions; v c the current speed of the driven vehicle; v f(xcrit) a speed of the tracked vehicle at a distance x crit is; x crit a distance at which a violation of the predetermined minimum time threshold occurs; t c a current tracking time; t f(xcrit) a time that the tracked vehicle needs to cover the distance x crit to reach; a i a vehicle acceleration of the driven vehicle with index i. Δx i an incremental distance between cell i and cell i+1; r w a rolling radius of a wheel of the driven vehicle in millimeters; and m is the mass of the driven vehicle in kilograms; β is a second safety factor that is larger than the first safety factor to avoid a violation of the predetermined minimum time threshold; and tmin∗ the predetermined minimum time threshold.

[0093] After block 414, the procedure continues with block 416. In block 416, given the new axle torque command (i.e., the torque adjustment) determined in block 414, the controller 34 recalculates the table of expected speeds PST of the driven vehicle 10 and the tracked vehicle 11, as well as the time / distance tables (i.e., the first distance table FDT, the second distance table SDT, and the track time table FTT). The forward control algorithm 400 then returns to block 406.

Claims

[1] Speed ​​control method (100) for controlling a powered vehicle (10), comprising: (102) Receiving a maximum permissible speed, a minimum permissible speed and a set speed by a control (34) of the driven vehicle (10); (104) Instructing a drive system by means of the control (34) to generate an instructed axle torque in order to maintain the set speed; (102) Monitoring the current speed of the driven vehicle (10); (106) Monitoring the height of a terrain at predetermined, upcoming locations of the powered vehicle (10); (108) Determining the expected speeds of the driven vehicle (10) at each of the predetermined upcoming locations using the current speed of the driven vehicle (10) and the elevation (E) of the terrain (Trr) at the predetermined upcoming locations; Monitoring the current speed of a tracked vehicle (11), wherein the tracked vehicle (11) is driving directly in front of the driven vehicle (10); Determining the expected speeds of the tracked vehicle (11) at each of the predetermined, upcoming locations using the current speed of the tracked vehicle (11) and the elevation (E) of the terrain at the predetermined, upcoming locations; (406) Determining a plurality of pursuit times at each of the predetermined, forthcoming locations using the expected speeds of the driven vehicle (10) and the expected speeds of the pursued vehicle (11), each of the plurality of pursuit times being a time required for the driven vehicle (10) to reach the pursued vehicle (11); (408) Compare each of the multiple tracking times with a predetermined minimum time threshold; (109, 408) Determine whether at least one of the multiple tracking times is smaller than the predetermined minimum time threshold; (414) in response to the determination that at least a plurality of tracking times is less than the predetermined minimum time threshold, instructing the drive system (20) of the driven vehicle (10) by the control (34) to reduce the instructed axle torque by a torque setting to prevent each of the plurality of tracking times at each of the predetermined upcoming locations from being less than the predetermined minimum time threshold; (108) Generating a table of predicted speeds using the predicted speeds of the driven vehicle (10) at each of the predetermined, upcoming locations of the driven vehicle (10), wherein the driven vehicle (10) includes a user interface (23) configured to allow a user to set the maximum permissible speed and the minimum permissible speed; (402) Generating a table of times required by the powered vehicle (10) to reach each of the predetermined upcoming locations, using the table of expected speeds; (404) Generating a table of the times required by the tracked vehicle (11) to reach each of the predetermined, upcoming locations; wherein the times required by the tracked vehicle (11) to reach each of the predetermined upcoming locations are determined using the expected speeds of the tracked vehicle (11) at each of the predetermined upcoming locations, a vehicle acceleration of the tracked vehicle (11) and an initial distance between the driven vehicle (10) and the tracked vehicle (11) at a first of the predetermined upcoming locations; Determining the speed of the tracked vehicle (11), the acceleration of the tracked vehicle (11) and the initial distance between the driven vehicle (10) and the tracked vehicle (11) at the first of the predetermined upcoming locations using one or more radars of the driven vehicle (10); Determining a difference between the times required by the driven vehicle (10) to reach each of the predetermined, imminent locations, using the table of expected speeds, and the times required by the tracked vehicle (11) to reach each of the predetermined, imminent locations, to determine each of the plurality of tracking times; in response to determining that each of the plurality of tracking times is equal to or greater than the predetermined minimum time threshold, instructing the drive system (20) of the driven vehicle (10) by the control (34) to maintain the instructed axle torque; Determining the torque setting, wherein: the predetermined minimum time threshold is equal to a minimum tracking time multiplied by a first safety factor; and the torque setting is a function of a current speed of the driven vehicle (10), a current speed of the tracked vehicle (11) and a vehicle acceleration of the driven vehicle (10) at the predetermined, upcoming locations; where the torque setting is calculated using the following equation: Δτaz=rwm[[vc−vf(xcrit)][tc−tf(xcrit)−βtmin∗]]−1xN∑i=0N−1aiΔxi where: Δτaz a change in axle torque to meet a variety of auto-tracking distance conditions; v c the current speed of the driven vehicle (10) is; v f(xcrit) a speed of the pursued vehicle (11) at a distance; x crit a distance at which a violation of the predetermined minimum time threshold occurs; t c a current tracking time; t f(xcrit) a time that the tracked vehicle (11) needs to cover the distance x crit to reach; a i a vehicle acceleration of the driven vehicle (10) with index i. Δx j an incremental distance between cell i and cell i+1; r w a rolling radius of a wheel of the driven vehicle (10) in millimeters; and m is a mass of the driven vehicle (10) in kilograms; β is a second safety factor that is larger than the first safety factor to avoid a violation of the predetermined minimum time threshold; and t*min the predetermined minimum time threshold. [2] Vehicle system (89), comprising: a drive system (20), and a control unit (34) that communicates with the drive system (20); wherein the control unit (34) is programmed to execute the speed control method (100) for controlling a driven vehicle (10) according to claim 1.

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