A system that controls the vehicle's recovery mode.
The control system improves vehicle recovery assistance by dynamically adjusting braking forces based on traction and environmental conditions, ensuring effective traction maintenance during recovery operations.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- JAGUAR LAND ROVER LTD
- Filing Date
- 2024-06-05
- Publication Date
- 2026-06-25
AI Technical Summary
Existing vehicle recovery assistance systems face challenges in maintaining traction during recovery processes due to terrain characteristics and the weight of the object being recovered, leading to potential loss of traction and unsuccessful recovery.
A control system that determines the traction force of each wheel and adjusts braking to maintain traction by applying different braking forces to wheels based on their proximity to the hitch point and environmental conditions, using processors to receive traction and torque data and output control signals to the vehicle's braking system.
The system enhances traction control during recovery, allowing vehicles to efficiently move objects without significant wheel slip by dynamically adjusting braking forces based on traction thresholds and environmental factors.
Smart Images
Figure 2026520959000001_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a vehicle control system and a control method for controlling a recovery assistance mode of a vehicle. Aspects of the invention relate to a control system, a system, a vehicle, and a method.
Background Art
[0002] It is known to use a vehicle to provide recovery assistance to another malfunctioning vehicle, a slippery road surface such as mud or sand, or an object immobilized by an obstacle on the ground. When performing recovery assistance, usually, the vehicle is connected to a recovery vehicle via a hitch point and a towing rope. Thereafter, the vehicle starts driving and pulls the object to another location. This is for obtaining further assistance or moving the object to a location where it can move. However, due to factors such as the characteristics of the terrain on which the vehicle travels and the weight of the object, it may be difficult for the vehicle to maintain traction throughout the recovery process, which may prevent the success of the recovery.
[0003] The present invention aims to solve one or more drawbacks related to the prior art.
Summary of the Invention
[0004] Aspects and embodiments of the present invention provide a control system, a system, a vehicle, a method, and computer-readable instructions as recited in the claims.
[0005] The present disclosure provides a technique for improving the recovery assistance of a vehicle. This technique determines the traction of the vehicle's wheels when torque is applied, and controls the braking applied to the wheels as the determined traction approaches a predetermined traction threshold.
[0006] According to one aspect of the present invention, a control system is provided for controlling a vehicle recovery mode for recovering an object connected to the vehicle's hitch point. The control system includes one or more processors configured to receive a traction force signal indicating a threshold of traction force required by one or more of the vehicle's wheels to move the object. The one or more processors are also configured to receive torque data from the vehicle's torque supply system. The torque data indicates the torque acting on one or more of the vehicle's wheels, and based on the torque data, the traction force of one or more of the vehicle's wheels is determined. Furthermore, the one or more processors are configured to output a control signal to the vehicle's braking system to control the braking of one or more of the wheels as the determined traction force approaches the traction force threshold.
[0007] In this way, the recovery vehicle is less likely to lose traction during the recovery process, allowing for more efficient recovery. The traction threshold corresponds to the amount of traction required by each wheel of the first vehicle to move the object. As torque is applied to the drivetrain and the traction approaches the traction threshold, braking can be controlled to increase traction between the vehicle's wheels and the surface on which they are located. In this regard, the traction threshold required for wheels near the hitch point may be higher than that for wheels further away from the hitch point. This is due to the additional load from the object at the hitch point. Therefore, wheels near the hitch point may require a different amount of braking force than those further away from the hitch point. Thus, each wheel may have the same or different traction thresholds, and similarly, the same or different braking forces may be applied to each wheel.
[0008] The control system includes one or more controllers, each comprehensively comprising at least one electronic processor having an electrical input for receiving input signals, and at least one memory device electrically connected to at least one electronic processor, which stores commands. The at least one electronic processor is configured to access at least one memory device and execute its commands to: receive traction force signals indicating a threshold of traction force required for one or more wheels of the vehicle to move an object; receive torque data from the vehicle's torque supply system, which indicates the torque acting on one or more wheels of the vehicle; determine the traction force of one or more wheels of the vehicle based on the torque data; and output control signals to the vehicle's brake system to control the brakes on one or more wheels as the determined traction force approaches the traction force threshold.
[0009] Optionally, one or more processors may be configured to output control signals to the vehicle's braking system to apply brakes to one or more wheels as the determined traction force approaches the traction force threshold, and to reduce the brakes at a predetermined speed when the determined traction force exceeds the traction force threshold.
[0010] In this way, the vehicle's brakes are preloaded until the traction force reaches a threshold, increasing the traction force between the vehicle and the ground. Then, once the actual traction force reaches the threshold, the brakes are gradually dampened, allowing the vehicle to slowly begin moving without significant wheel slip.
[0011] Optionally, one or more processors may be configured to jointly determine a predetermined speed depending on a determined traction force. In this case, the predetermined speed increases as the determined traction force decreases with increasing vehicle speed.
[0012] In this way, as the vehicle begins to move forward and the amount of traction decreases with increasing speed, the applied brakes are reduced more rapidly.
[0013] Optionally, one or more processors may be collectively configured to determine a predetermined rate based at least partially on one or more environmental conditions of the vehicle.
[0014] In this way, the braking reduction rate is adjusted according to the vehicle's environmental conditions. For example, if the road surface on which the vehicle is located is wet, icy, loose, or prone to damage, the braking is reduced at a slower rate. Optionally, one or more environmental conditions may include one or more of the terrain mode, temperature, and signals indicating the operation of one or more of the vehicle's windshield wipers.
[0015] Optionally, the predetermined speed may include a first predetermined speed for the first wheel set and a second predetermined speed for the second wheel set.
[0016] In this way, the braking of each wheelset (e.g., front wheels or rear wheels) is damped at different speeds. This allows for the maintenance of traction on wheels that are prone to slipping during recovery (e.g., axles with less vertical load). For example, by damping the braking of wheels closer to the hitch point at a faster speed and the braking of wheels further away from the hitch point at a slower speed, traction on these wheels can be maintained for a longer period. It is understood that the first wheelset is connected to the first axle, and the second wheelset is connected to the second axle.
[0017] Optionally, one or more processors can be configured to output control signals to the vehicle's braking system, reducing braking to a first wheelset to near zero and braking to a second wheelset to a predetermined level. For example, the first wheelset might include a pair of wheels close to the hitch point, while the second wheelset might include a pair of wheels further away from the hitch point.
[0018] In this way, a small amount of braking is applied to wheels prone to slipping throughout the entire auxiliary recovery operation. For example, maintaining a small amount of braking on wheels far from the hitch point where there is little vertical load can improve the traction of these wheels.
[0019] Optionally, the traction force signal may include resistance data indicating the coefficient of friction between one or more wheels of the vehicle and the surface on which the vehicle is located. In this case, one or more processors may be further configured to determine a threshold traction force required by one or more wheels of the vehicle to move an object, based on the resistance data and the vehicle's weight distribution.
[0020] In this way, the traction threshold for one or more wheels is determined based on the coefficient of friction between the wheel and the ground (e.g., estimated by the traction resistance system) and the vehicle's weight distribution. In this regard, the weight distribution may be uneven due to factors such as the vehicle's inclination or the load exerted by the object on the hitch point. Therefore, different traction thresholds may be determined for each wheel. Optionally, the weight distribution may be determined based on the height and / or air pressure of the suspension system at each wheel of the vehicle.
[0021] The traction force signal may include a target limit of torque that the vehicle's drivetrain should apply to move the object. In this case, one or more processors are further configured to determine a threshold of traction force required by one or more wheels of the vehicle to move the object, depending on the target limit of torque to be applied and the radius of one or more wheels.
[0022] The target torque limit corresponds to the amount of longitudinal force that the drivetrain must act on the wheels of the first vehicle to move the object from a stationary position while maintaining traction. On the other hand, the traction threshold corresponds to the amount of traction force required by the vehicle's wheels to move the object. Therefore, the traction threshold can be determined by dividing the target torque limit to be applied by the wheel radius. In such cases, the traction threshold determined from the target torque limit can be used to refine the estimation of the coefficient of friction.
[0023] Optionally, one or more processors may be further configured to receive gradient data indicating the gradient of the vehicle, resistance data indicating the rolling resistance between the vehicle and the surface on which the vehicle is located, load data indicating the load from the object to the hitch point, and to determine a target limit value of the torque that the vehicle's drivetrain should apply to move the object, based on the gradient data, resistance data, and load data.
[0024] Optionally, one or more wheels may include a pair of wheels close to the hitch point. One or more wheels may also include a pair of wheels further away from the hitch point.
[0025] According to another aspect of the invention, a system is provided that includes the control system and a vehicle braking system.
[0026] Optionally, the system may also include a vehicle torque transmission system.
[0027] In yet another embodiment, a vehicle equipped with the above system or the above control system is provided.
[0028] As yet another aspect, a method for controlling a recovery mode of a vehicle to recover an object connected to a hitch point of the vehicle is provided. The method includes receiving a traction force signal indicating a threshold value of a traction force required for one or more wheels of the vehicle to move the object. The method also includes receiving torque data from a torque supply system of the vehicle. Here, the torque data indicates the torque acting on one or more wheels of the vehicle, and based on the torque data, the traction force of one or more wheels of the vehicle is determined. Further, as the determined traction force approaches the threshold value, a control signal is output to a brake system of the vehicle to control the brakes of the one or more wheels.
[0029] According to yet another aspect of the invention, computer-readable instructions configured to execute the method as described above when executed by a computer are provided.
[0030] In the scope of the present application, various aspects, embodiments, examples, and alternatives described in the foregoing paragraphs, claims, and / or the following description and drawings, particularly their individual features, are explicitly intended to be adopted independently or in any combination. That is, all embodiments and / or features of any embodiment can be combined in any manner and / or combination as long as those features do not conflict with each other. The applicant reserves the right to amend the originally filed claims or to file new claims accordingly. This also includes the right to amend the originally filed claims to depend on or incorporate features of other claims that were not originally so claimed.
Brief Description of the Drawings
[0031] One or more embodiments of the present invention will be described, by way of example only, with reference to the accompanying drawings. In the drawings:
[0032] [Figure 1] FIG. 1 is a block diagram showing a control system according to an embodiment of the present invention.
[0033] [Figure 2A] Figure 2A shows a schematic diagram of a vehicle according to an embodiment of the present invention.
[0034] [Figure 2B] Figure 2B shows a schematic diagram of the rear view of the vehicle shown in Figure 2A.
[0035] [Figure 3] Figure 3 shows a first flowchart illustrating the operations performed by the control system shown in Figure 1 according to an embodiment of the present invention.
[0036] [Figure 4] Figure 4 is a second flowchart showing the operations performed by the control system shown in Figure 1 according to an embodiment of the present invention.
[0037] [Figure 5] Figure 5 is a schematic diagram showing the operation of the vehicle in Figure 2A during the operation performed by the control system in Figure 1.
[0038] [Figure 6A] Figure 6A is a schematic diagram showing the operation of the vehicle in Figure 2A during the operation performed by the control system in Figure 1.
[0039] [Figure 6B] Figure 6B is a schematic diagram showing the operation of the vehicle in Figure 2A during the operation performed by the control system in Figure 1. [Modes for carrying out the invention]
[0040] Referring to Figure 1, a vehicle control system 100 is shown. The control system 100 shown in Figure 1 comprises one controller 110, but it will be understood that this is merely an example. The controller 110 includes processing means 120 and storage means 130. The processing means 120 is one or more electronic processing devices 120 that execute computer-readable commands. The storage means 130 is one or more storage devices 130. The storage means 130 is electrically connected to the processing means 120. The storage means 130 is configured to store commands, and the processing means 120 is configured to access the storage means 130 and execute the commands stored therein.
[0041] The controller 110 includes an input means 140 and an output means 150. The input means 140 may include an electrical input unit 140 of the controller 110. The output means 150 may include an electrical output unit of the controller 110. The input means 140 is configured to receive a traction force signal 160 indicating a threshold traction force required for one or more wheels of the vehicle to move an object connected to the vehicle's hitch point. Optionally, the traction force signal 160 indicates a target limit of torque applied to the vehicle's drivetrain during object recovery assistance, from which the traction force threshold is derived. The traction force signal 160 includes one or more of a gradient signal, a resistance signal, and a load signal from which the traction force threshold and / or the target limit of torque are derived. The gradient signal is an electrical signal indicating the gradient of the vehicle. The gradient signal is received from the vehicle's inertial measuring device. The resistance signal is an electrical signal indicating the rolling resistance between the vehicle and the surface on which the vehicle is located, and / or the coefficient of friction between the vehicle and the surface on which the vehicle is located. Resistance signals may be received from the vehicle's traction resistance system. Load signals are electrical signals that indicate changes in the load on the vehicle. Load signals are received from the vehicle's suspension system and include data indicating changes in one or more characteristics of the vehicle's suspension system, such as the height and / or air pressure of the vehicle's front and / or rear suspensions. This indicates changes in the load on the vehicle.
[0042] The input means 140 is also configured to receive a torque signal 162 from the vehicle's torque supply system. The torque signal 162 is an electrical signal indicating the amount of torque supplied to the vehicle's drivetrain and / or one or more wheels. The input means 140 may optionally be configured to receive environmental condition signals 164 from one or more sensors of the vehicle indicating one or more environmental conditions under which the vehicle is operating. For example, the environmental condition signals 164 may include one or more of the following: a terrain mode signal indicating the vehicle's terrain mode, a temperature signal from a temperature sensor indicating the ambient temperature, and a signal indicating the operation of the vehicle's windshield wipers. The input means 140 may further optionally be configured to receive a recovery mode signal 166 from a user via the vehicle 200's human-machine interface (HMI). This signal instructs the controller 110 to start driving the vehicle in a recovery mode to assist in the recovery of the target.
[0043] The output means 150 is configured to output a brake control signal 170 to the vehicle's brake system to control one or more of the vehicle's braking characteristics. The output means 150 may optionally be configured to output a torque control signal 172 to the vehicle's torque supply system. The torque control signal 172 indicates a target torque limit that the vehicle's drivetrain should apply during the assisted recovery of the subject. The output means 150 may further optionally be configured to output a driver control signal 174 to the vehicle's human-machine interface (HMI) requesting the vehicle's driver to move the vehicle. If the vehicle is an autonomous or semi-autonomous vehicle, it is understood that the control signal 174 may be output to the autonomous control system.
[0044] Figure 2A shows a vehicle 200 according to an embodiment of the present invention. The vehicle 200 includes the controller 100 shown in Figure 1. The controller 110 is mounted inside the vehicle 200 and can communicate with the brake system 220 of the vehicle 200 so that it can transmit a brake control signal 170 to the brake system 220. Furthermore, the controller 110 can also communicate with a torque supply system 225 located inside the vehicle 200 and can receive a torque signal 162 from the torque supply system 225. It can also transmit a torque control signal 172 to the torque supply system 225 as needed. The vehicle 200 may be an EGO vehicle, that is, a vehicle equipped with autonomous driving technology or semi-autonomous driving technology that can sense the environment and navigate without direct input from a human driver.
[0045] Vehicle 200 has at least one hitch point (hitch point) for connecting vehicle 200 to an object that needs to be recovered or moved to another location. For example, vehicle 200 may have a first hitch point 210A located near the front wheel set 280A, 280B on the front of vehicle 200. This is merely an example, and it goes without saying that the first hitch point 210A may be located at any suitable location on the front of vehicle 200. Similarly, multiple hitch points may be located on the front of vehicle 200.
[0046] Figure 2B shows a rear view of the vehicle 200 in Figure 2A. The vehicle 200 may also be provided with a second hitch point 210B located near the rear wheels 280C, 280D at the rear of the vehicle 200 for connecting the vehicle 200 to an object requiring recovery. This is merely an example, and the second hitch point 210B may be located at any suitable position at the rear of the vehicle 200. Similarly, multiple hitch points may be provided at the rear of the vehicle 200. It is also understood that the vehicle 200 may have either or both of the first hitch point 210A and the second hitch point 210B. The hitch points 210A and 210B provide connection points for attaching ropes or other connecting means to the vehicle 200. This connects the vehicle 200 to an object requiring recovery.
[0047] The torque transmission system 225 may be configured to supply torque to at least one wheel 280A-D. Similarly, the brake system 220 may be configured to supply brake torque to at least one wheel 280A-D. In this regard, it will be understood that the wheels 280A-D are controlled individually and torque and brake torque may be applied directly to them. Optionally, the front wheel set 280A, 280B may be connected to the first axle, and the rear wheel set 280C, 280D may be connected to the second axle. Thus, the torque supply system 225 is configured to supply torque to either or both of the first and second axles, thereby supplying torque to at least one wheel 280A-D. Similarly, the brake system 220 is configured to supply brake torque to either or both of the first and second axles, thereby providing braking force to at least one wheel 280A-D.
[0048] Naturally, vehicle 200 can be operated to assist in the recovery of any suitable object, including but not limited to a second vehicle, trailer, boat, rock, log, or any object whose weight does not exceed the power capacity of vehicle 200.
[0049] Figure 3 is a flowchart 300 according to an embodiment of the present invention. The flowchart 300 shows the steps that the control system 100 performs when controlling the recovery mode of a vehicle 200, such as the vehicle 200 shown in Figures 2A and 2B. In particular, the memory 130 may contain computer-readable instructions that, when executed by the processor 120, perform the method 300 according to an embodiment of the present invention.
[0050] In step 310, the control system is configured to receive a traction force signal 160 indicating a threshold traction force required for one or more wheels 280A-D of the vehicle 200 to move an object connected to the hitch points of the vehicle 200. One or more wheels 280A-D may include pairs of wheels that are close to the hitch points 210A, 210B. Optionally, one or more wheels 280A-D may further include pairs of wheels that are located away from the hitch points 210A, 210B.
[0051] Optionally, the traction force signal 160 is generated by the controller 110 based on receiving data regarding the coefficient of friction between the vehicle 200 and the surface on which the vehicle 200 is located (for example, estimated by the vehicle 200's traction resistance system) as the input signal 160.
[0052] Alternatively, the traction force signal 160 is additionally generated by the controller 110 based on the input signal 160 receiving data regarding the target torque limit applied to the drivetrain of the vehicle 200 during the support recovery of the target. Optionally, this target torque limit may also be generated by the controller 110 based on the input signal 160 receiving data regarding the gradient of the vehicle 200, the rolling resistance of the vehicle 200, and the loads acting on the hitch points 210A and 210B by the target. This will be discussed later with reference to Figure 4.
[0053] Generally, the traction force is determined by one of the following elements: the amount of torque acting on the wheels of the vehicle 200; the radius of the wheels 280A-D; the gradient of the vehicle 200; the coefficient of friction between the wheels 280A-D and the underside 270 (e.g., estimated by the traction resistance system of the vehicle 200); and the weight of each wheel set 280A-D. The weight of each wheel set 280A-D can be based on the weight of the vehicle 200 at zero gradient, and it is understood that the weight of the vehicle 200 is stored as data in the memory means 130. Alternatively, or additionally, the weight of each wheel set 280A-D may also be estimated, but not limited to, variations in data received from the suspension system of the vehicle 200, such as changes in suspension height or air pressure (these indicate changes in weight distribution).
[0054] Figures 6A-B illustrate an example of how to determine the traction force. Figure 6A shows vehicle 200 before load is applied to hitch points 210A and 210B. The maximum traction force required to move vehicle 200 is typically defined as the product of the coefficient of friction μ at each wheelset 280A-B and 280C-D of vehicle 200 and the weight (mass × gravity) mg (generally represented by C). Assuming that the front wheels 280A-B and rear wheels 280C-D are approximately equidistant from the center point of the vehicle (i.e., the center of mass) at zero gradient, the weight of each wheelset 280A-B and 280C-D (approximately shown as A and B) is approximately 1 / 2 mg, and the suspension height and / or air pressure (approximately shown as D and E) are roughly equal. As shown in Figure 6B, when an object (not shown) is connected to the rear hitch point 210B (e.g., via a tow rope 260), this results in a load transfer from the front wheels 280A to the rear wheels 280C, and the center of gravity (indicated by C) shifts towards the rear wheels 280C-D. As a result, the weight on each wheelset 280A-B and 280C-D changes. Consequently, the suspension data may show changes in suspension height and air pressure at both ends of the vehicle 200, suggesting a new weight distribution. For example, the suspension height at the front of the vehicle 200 (indicated by D) may increase, while the suspension height at the rear of the vehicle 200 (indicated by E) may decrease due to the additional load on the rear hitch point 210B. As a result, the position of the center of gravity (indicated by C) changes, so the weight on the front wheels 280A-B (indicated by A) decreases to 3 / 8 mg (3 / 8 of the total weight), while the weight on the rear wheels 280C-D (indicated by B) may increase to 5 / 8 mg (5 / 8 of the total weight). This example shows the case where the gradient is zero, but naturally, if the gradient is not zero, the weight distribution will be further affected. For example, if vehicle 200 is facing uphill, the load transfer to the rear wheels 280C-D may increase as a result. Similarly, if vehicle 200 is facing downhill, the amount of load transfer to the rear wheels 280C-D will be less than when the gradient is zero, and depending on the degree of the incline, the load may instead be transferred to the front wheels 280A-B (i.e., the load on the rear wheels 280C-D decreases).
[0055] Thus, in step 310, the processing means 120 determines the traction force threshold based on the coefficient of friction between the wheels 280A-D and the underside 270 (for example, estimated by the traction resistance system of the vehicle 200) and the weight of each wheel set 280A-D by executing commands stored in the storage means 130. Therefore, it will be understood that the traction force threshold will be higher for the wheels 280A-D that receive the largest vertical load (i.e., weight). For example, using the above example, the traction force threshold will be higher for the rear wheels 280C-D compared to the front wheels 280A-B, which receive less vertical load.
[0056] The torque at each wheel 280A-D can also be defined as the traction force pmg multiplied by the radius of the wheel 280A-D. Therefore, the processing unit 120 may, additionally or alternatively, be configured to determine a traction force threshold based on a target limit value of the applied torque. This target limit value is received as an input signal 160 or generated by the controller 110, as described later with reference to Figure 4. Given a target limit value of the torque to be applied, the traction force threshold is calculated by dividing the target limit torque by the wheel radius to obtain the traction force threshold at each wheel 280A-D. Optionally, the traction force threshold at each wheel 280A-D may be further adjusted by the weight distribution in each wheel set 280A-D. This increases the traction force limit again at the wheel receiving the largest vertical load.
[0057] Thus, in step 310, the processing means 120 determines a threshold traction force based on the target torque limit value and the radius of the wheels 280A-D of the vehicle 200 (which may be stored as data in the storage means 130) by executing an instruction stored in the storage means 130.
[0058] Optionally, the processing means 120 may be configured to adjust the friction coefficient estimated by the traction resistance system 200 based on a traction force threshold determined from the target torque limit. In this regard, if the traction force threshold determined from the target torque limit is higher than the traction force threshold determined from the estimated friction coefficient, the friction coefficient estimation can be refined, for example, by increasing the friction coefficient. This ensures that the resulting traction force threshold matches the threshold determined from the target torque limit. Similarly, the processing means 120 may be configured to adjust or verify the target torque limit based on the traction force threshold determined from the friction coefficient estimated by the traction resistance system 200. In step 320, when torque is applied to the drive system to move the vehicle 200, the control system 100 is configured to receive torque data of the vehicle 200. The torque data is received as an input signal 162 in the input means 140 of the controller 110 and includes data indicating the torque applied to one or more wheels of the vehicle 200. From the torque data, in step 330, the processing means 120 is configured to determine the traction force of the wheels 280A-D of the vehicle 200 while torque is being applied. This is also done based on the amount of torque applied to one or more wheels 280A-D of the vehicle 200 and the radius of the wheels 280A-D.
[0059] Once the processing means 120 determines the traction force of one or more wheels 280A-D of the vehicle 200, in step 340, the controller 110 outputs a control signal 170. This causes the vehicle 200's braking system 220 to control the brakes applied to one or more wheels 280A-D of the vehicle 200 as the measured traction force approaches the traction force threshold received or determined in step 310. For example, the control signal 170 causes the braking system 220 to pre-load the brakes applied to the wheels 280A-D of the vehicle 200 as the measured traction force approaches the threshold, thereby increasing the traction force between the wheels of the vehicle 200 and the ground 270. Then, when the measured traction force exceeds the traction force threshold, the braking force applied at a predetermined speed is gradually reduced. This allows the vehicle 200 to start moving slowly without large wheel slip. In this regard, the measured traction force may reach a level that exceeds the threshold. At that level, the threshold is based on estimated parameters such as the estimated coefficient of friction and the target torque limit. When the measured traction force reaches the traction force threshold and the vehicle 200 begins to move, the traction force of the vehicle 200 decreases in proportion to the increase in speed. Therefore, it becomes possible to gradually reduce the applied braking force and increase the torque supplied by the torque supply system 225 in a controlled manner.
[0060] Optionally, the processing means 120 may be configured to determine a predetermined speed at which the brakes are reduced, depending on the traction force determined in step 330. This predetermined speed decreases as the measured traction force decreases with increasing speed. In this regard, the traction force may be continuously determined as torque is applied to one or more wheels 280A-D of the vehicle 200. Therefore, as the traction force decreases and as the speed of the vehicle 200 increases, the brakes applied to one or more wheels can be reduced more rapidly. Optionally, when the measured traction force reaches a threshold of traction force, the predetermined speed at which the brakes are reduced may be associated with the decrease in traction force with increasing speed as a percentage of the traction force threshold. For example, each time the measured traction force decreases by an amount equivalent to 10% of the threshold, the brakes can be reduced and reduced by a corresponding percentage (e.g., 10%).
[0061] Furthermore, or alternatively, the processing means 120 may be configured to determine a first predetermined rate for the first wheel set and a second predetermined rate for the second wheel set. For example, the first wheel set has a pair of wheels near the hitch point (e.g., wheels 280C, 280D when the rear hitch point 210B is in use), and the second wheel set has a pair of wheels away from the hitch point (e.g., wheels 280A, 280B when the rear hitch point 210B is in use). In this way, the brakes on each axle are damped at different speeds to maintain traction on the wheels 280A-D (e.g., the pair of wheels on the axle with less vertical load) which are more prone to slipping during restoration. For example, by damping the brakes on the wheels closer to the hitch point at a faster speed and the brakes on the wheels further away from the hitch point at a slower speed, it is possible to maintain traction on these wheels for a longer period of time.
[0062] Furthermore, or alternatively, the processing means 120 may be configured to determine a predetermined speed at which the brakes are reduced in response to one or more environmental conditions of the vehicle 200. In this regard, the control system 100 may be configured to receive one or more environmental conditions as input signals 164 in the input means 140 of the controller 110. The input signals 164 include one or more of the following: a terrain mode signal indicating the terrain mode of the vehicle, a temperature signal from a temperature sensor indicating the ambient temperature, and a signal indicating the operation of one or more wipers of the vehicle 200. The processing means 120 is configured to determine a predetermined deceleration rate based on the received environmental conditions. For example, if the terrain mode of the signal indicates terrain where traction resistance may be reduced (e.g., snow terrain mode, sand terrain mode, mud terrain mode), the brakes applied to one or more wheels may be reduced at a relatively slower speed compared to the speed used in normal road driving mode. As another example, if the temperature signal indicates that the ambient temperature is below 0°C and the road surface on which the vehicle 200 is traveling may be frozen, traction resistance may be reduced. In this case, the brakes applied to one or more wheels may be reduced at a relatively slower speed compared to the braking speed used at temperatures above 0°C. As yet another example, if a signal is received indicating that one or more of the windshield wipers have been activated, it means that the road surface on which vehicle 200 is traveling is wet. Therefore, the traction resistance is reduced. In this case, the brakes applied to one or more wheels can be dampened at a relatively slower rate compared to when the road is dry.
[0063] Furthermore, or alternatively, the control signal 170 may be configured to cause the braking system 220 to reduce the braking force applied to the first wheelset (e.g., the pair of wheels closer to the hitch point) to near zero, and the braking force applied to the second wheelset (e.g., the pair of wheels further from the hitch point) to a predetermined level. In this regard, it is understood that the predetermined level may be an adjustable value depending on factors such as terrain mode, gradient, and other environmental conditions. Thus, the predetermined level may be determined from a lookup table of values associated with different operating variables. In this way, a small amount of brake is applied to the wheels most susceptible to the effects of slip throughout the entire assist recovery operation. For example, maintaining a small amount of brake on wheels far from the hitch point with a small vertical load (e.g., the front wheels 280A-B when the rear hitch point 210B is in use) can improve the traction of these wheels.
[0064] Figure 4 shows a flowchart 400 according to an embodiment of the present invention. Flowchart 400 shows additional steps performed by the control system 100 when controlling the recovery mode of a vehicle 200, such as the vehicle 200 shown in Figures 2A and 2B. Referring to Figure 5, this flowchart can be used in conjunction with method 300 described with reference to Figure 3. In particular, memory 130 may contain computer-readable instructions that, when executed by the processor 120, perform method 400 according to an embodiment of the present invention. In the example shown in Figure 5, vehicle 200 is provided with assisted recovery to a recovery vehicle 250. The front hitch point 255A of the recovery vehicle 250 is attached to the rear hitch point 21OB of vehicle 200 by a connecting means such as a tow rope 260. This is merely an example, and it goes without saying that the recovery vehicle 250 can be replaced with any object that requires recovery or movement to another location.
[0065] Optionally, in step 410, the control system is configured to receive user input data from the human-machine interface of the vehicle 200. The user input data is received as an input signal 166 in the input means 140 of the controller 100 and includes data indicating a request to start operation of the vehicle 200 in recovery mode.
[0066] In step 420, the control system 100 is configured to acquire tilt data of the vehicle 200. The tilt data is acquired as an input signal 160 in the input means 140 of the controller 110 and includes data indicating the tilt of the vehicle 200 as measured by the vehicle's inertial measuring unit (IMU). It is understood that the tilt of the vehicle 200 indicates the tilt of the surface 270 on which the vehicle 200 is located. In the example shown in Figure 5, the surface 270 is substantially horizontal, but it is understood that the surface 270 may be tilted, for example, if the vehicle 200 is on a slope.
[0067] In step 430, the control system 100 is configured to receive traction resistance data for the vehicle 200. The traction resistance data is received as another input signal 160 in the input means 140 of the controller 110 and includes data indicating the rolling resistance between the vehicle 200 and the surface 270 on which the vehicle 200 is located, more specifically between the wheels of the vehicle 200 and the surface 270 below. The rolling resistance depends on the vertical load on the wheels (illustrated by arrow A in Figure 5) and the rolling resistance coefficient between the wheels and the road surface 270. The rolling resistance coefficient is a measure of the resistance force generated by the wheels when they move over a deformable road surface such as mud. For example, the rolling resistance coefficient of a tire set running on a smooth paved road will be lower than that of a tire set running on mud or sand. The traction resistance data is measured by the traction resistance system of the vehicle 200. In this regard, it is understood that the rolling resistance coefficient can be estimated in relation to the gradient and speed of the vehicle 200 using various systems within the vehicle 200, such as torque sensors and torque measurements from the powertrain.
[0068] In step 440, the control system 100 is configured to receive a load signal including suspension system data for the vehicle 200. The suspension system data is received as a further input signal 160 in the input means 140 of the controller 110 and includes data indicating a change in the height of the vehicle 200's suspension (illustrated by arrow B in Figure 5) near at least one of the hitch points 210A, 210B (i.e., a change in the height B of the suspension at the front and / or rear of the vehicle 200). The suspension system data may also include data indicating the displacement of the suspension system. This displacement is measured by one or more position sensors, for example. Alternatively, if the suspension system is an auto-leveling air suspension system, the suspension system data may include data indicating a change in the air pressure supplied to the suspension system to change or maintain the vehicle height of the vehicle 200. As previously stated, a change in the height B of the suspension system, or a change in the air pressure within the suspension system, indicates a change in the load on hitch point 210B, because this increase in load causes a corresponding increase in the vertical load A, which compresses the suspension. The automatic horizontal adjustment air suspension system operates against this compressive force. Therefore, the suspension system data of the vehicle 200 can be used by the processor 120 to determine the load on the hitch point 210B. For example, as shown in Figure 5, when a recovery vehicle 250 is connected to the vehicle 200 via the rear hitch point 210B and tension is applied to the towing rope 260, the vehicle 200 experiences an increase in load at the hitch point 210B. This causes a proportional increase in the vertical load B, resulting in a displacement of the rear suspension or a change in the amount of air supplied to the rear suspension. In this regard, it is understood that the amount of load on the hitch point 210B depends on the weight of the recovery vehicle 250, the gradient of the road surface 270 on which the recovery vehicle 250 is located, and the direction in which the vehicle 200 is towing the object along that gradient (i.e., uphill or downhill).
[0069] Steps 420, 430, and 440 can be performed in parallel or sequentially, and it goes without saying that the data can be received simultaneously or in any order as input signal 160.
[0070] In step 450, the control system 100 is configured to determine a target torque limit to be applied by the drivetrain of the vehicle 200, based on the load determined from the gradient data, traction resistance data, and suspension system data. In this regard, the processing means 120 receives an input signal 160 from the input means 140 and executes a command stored in the storage means 130 to determine the target torque limit to be applied by the drivetrain. This target torque limit corresponds to the magnitude of the longitudinal force that the drivetrain needs to act on the wheels of the vehicle 200. This moves the recovery vehicle 250 from its stationary position while maintaining sufficient traction between the wheels 200 and the ground 270, thereby avoiding wheel slippage.
[0071] Once the processing means 120 determines a target limit value for the torque applied by the drive system of the vehicle 200, the processing means 120 uses this target limit value for torque to determine the required traction force threshold, as described in step 310 above.
[0072] Optionally, once a target torque limit is determined, the controller 110 may, in step 460, output a control signal 172 to prompt the vehicle's torque supply system 220 to control the drivetrain when power is supplied to it. In this regard, the torque supply system 220 may be configured to control the drivetrain so that the amount of torque applied by the drivetrain does not exceed the determined target limit when power is supplied to it.
[0073] Optionally, when an initial target torque limit is output to the torque supply system 220, the controller 110 is configured in step 470 to output a signal 174 to the human-machine interface of the vehicle 200, thereby instructing the driver of the vehicle 200 to begin moving the vehicle 200 forward to move the target (e.g., the recovery vehicle 250) if not already done. Once the initial target torque limit is determined and output to the torque supply system 220, the target torque limit can be adjusted throughout the entire assisted recovery operation by repeatedly performing steps 420-450. In this regard, the control system 100 is configured to repeatedly receive the input signal 160, and the determined target torque limit is changed if one or more of the gradient signal, resistance signal, or load signal changes.
[0074] In this regard, the input signal 160 can be received at any appropriate time, but is not limited to, before torque is applied by the torque supply system 220, when torque is applied by the torque supply system 220, and repeatedly whether or not torque is applied by the torque supply system 220. Thus, the input signal 160 is received at the first point before assisted towing is initiated, or when the vehicle 200 is connected to the target (e.g., recovery vehicle 250), has advanced far enough for the towing rope 260 to be under tension, and the initial load has been transmitted from the target to the hitch points 210A, 210B of the vehicle 200. At this time, rough measurements of towing resistance data and suspension system data are received and input as the input signal 160, and the initial target torque limit is determined. Thus, the target torque limit is first determined in step 450, after the recovery mode is activated in step 310, and the initial load is sensed through the change in the input signal 160. Subsequently, as support recovery is performed and torque is applied by the torque supply system 220, data related to the input signal 160 is repeatedly received, and the target torque limit is continuously adjusted and refined as further data is received. In this regard, when a target torque limit is determined, if the drive system applies torque up to that target limit and no movement of the vehicle 200 is detected, the target torque limit can be gradually increased until the vehicle 200 begins to move. Similarly, as the vehicle 200 moves, for example, if suspension data indicates that the vertical load at hitch points 210A and 210B has decreased due to the vehicle 200 traveling downhill, the target torque limit can be gradually decreased.
[0075] It will be understood that the present invention can be modified in various ways without departing from the scope of this application.
Claims
1. A control system for controlling the recovery mode of a vehicle to recover an object connected to the vehicle's hitch point, comprising one or more processors collectively configured, One or more wheels of the vehicle receive a traction force signal indicating a threshold traction force required to move the object; Receiving torque data from the torque supply system of the vehicle, wherein the torque data represents the torque acting on one or more wheels of the vehicle; Based on the torque data, determine the traction force of one or more wheels of the vehicle; A control system configured to output a control signal to the vehicle's brake system and control the brakes of one or more wheels as the determined traction force approaches a traction force threshold.
2. The control system according to claim 1, wherein the one or more processors are configured to output the control signal to the vehicle's braking system to apply the brakes to the one or more wheels as the determined traction force approaches the traction force threshold, and to begin reducing the brakes at a predetermined speed when the determined traction force exceeds the traction force threshold.
3. The one or more processors are configured to determine the predetermined speed depending on the determined traction force, The control system according to claim 2, wherein the predetermined speed increases as the vehicle speed increases and the determined traction force decreases.
4. The control system according to claim 2 or 3, wherein one or more processors are configured, at least in part, to determine the predetermined speed based on one or more environmental conditions of the vehicle.
5. The control system according to claim 4, wherein the one or more environmental conditions include one or more of terrain mode, temperature, and a signal indicating the operation of one or more wipers of the vehicle.
6. The control system according to any one of claims 2 to 5, wherein the predetermined speed includes a first predetermined speed for a first wheel set and a second predetermined speed for a second wheel set.
7. The control system according to any one of claims 2 to 6, wherein one or more processors are configured to output the control signal to the brake system of the vehicle, thereby reducing the braking force to the first wheel set to near zero and reducing the braking force to the second wheel set to a predetermined level.
8. The control system according to claim 6 or 7, wherein the first wheel set includes a pair of wheels close to the hitch point, and the second wheel set includes a pair of wheels away from the hitch point.
9. The traction force signal includes resistance data indicating the coefficient of friction between one or more wheels of the vehicle and the surface on which the vehicle is located. The control system according to any one of claims 1 to 8, wherein the one or more processors are further configured to determine the threshold traction force required by the one or more wheels of the vehicle to move the object, based on the resistance data and the weight distribution of the vehicle.
10. The traction force signal includes a target limit of torque that the vehicle's drivetrain should apply to move the object. The control system according to any one of claims 1 to 9, wherein the one or more processors are configured to determine the traction threshold required by the one or more wheels of the vehicle to move the object, depending on the target limit of the torque to be applied and the radius of the one or more wheels.
11. The aforementioned one or more processors Receive gradient data indicating the gradient of the vehicle; Resistance data indicating the rolling resistance between the vehicle and the surface on which the vehicle is located is received; The system receives load data indicating the load from the target to the hitch point; Based on the gradient data, resistance data, and load data, the system is configured to determine the target limit of the torque that the vehicle's drivetrain should apply to move the object. The control system according to claim 10.
12. A system comprising the control system described in any one of claims 1-11 and a vehicle braking system.
13. The system according to claim 12, including a torque supply system for the vehicle.
14. A vehicle comprising the system according to any one of claims 12 to 13, or the control system according to any one of claims 1 to 11.
15. A method for controlling the recovery mode of a vehicle for recovering an object to which an object has been towed to the vehicle's hitch point, One or more wheels of the vehicle receive a traction force signal indicating the traction force threshold required to move the object; By receiving torque data from the vehicle's torque supply system, the torque data indicates the torque acting on one or more wheels of the vehicle; Based on the torque data, determine the traction force of one or more wheels of the vehicle; A method for controlling the brakes of one or more wheels by outputting a control signal to the vehicle's brake system as the determined traction force approaches a traction force threshold.