Control system for a vehicle and procedures

Abstract

A control system (10LSP) for a motor vehicle that is configured to: Receiving propulsion demand information (410) indicating a quantity of propulsion required by a powertrain (129, 130) of the vehicle (100); Controlling a quantity of drive torque exerted by the drive train (129, 130) on one or more road wheels, depending at least partially on the drive requirement information; Receiving gradient information indicating a gradient of a driving surface (530); and Receiving speed information that displays the vehicle's speed over ground, wherein the control system is configured to automatically cause a braking system (12d, 540) to apply a braking force (330, 430) to one or more of the road wheels while the single-pedal creep function (590) is active, in order to substantially prevent the vehicle (100) from rolling backward, depending at least partially on the gradient information and speed information, wherein the control system is configured to adjust the level of the applied braking force (330) depending at least partially on the drive requirement information (410), wherein the control system is configured to adjust the amount of braking force (330, 430) applied depending at least partially on the drive requirement information (410), includes that the control system is configured to automatically and gradually apply braking force (330, 430) when an accelerator pedal (161) is released, wherein the control system is configured to disable the single-pedal creep function (590) in response to exceeding a vehicle speed threshold (100).

Description

INTRODUCTION THROUGH REFERENCE

[0001] The contents of the jointly pending British patent applications GB 2 507 622 A and GB 2 499 461 A are hereby incorporated by reference. The contents of US patent no. US 7 349 776 B2 and the pending international patent applications WO 2013 / 124 321 A1 and WO 2014 / 139 875 A1 are hereby incorporated by reference. The contents of British patent applications GB 2 492 748 A and GB 2 499 279 A, ​​as well as British patents GB 2 492 655 A and GB 2 508 464 A, are also hereby incorporated by reference. TECHNICAL AREA

[0002] The present disclosure relates to a vehicle control system and a control method, and in particular, but not exclusively, to a control system and a method for controlling the operation of one or more vehicle systems or subsystems in a land-based vehicle capable of operating in a variety of diverse and extreme terrain and conditions. Aspects of the invention relate to a control system, a control system, a vehicle, a method, a non-volatile, computer-readable carrier medium containing computer-readable code, a computer program product executable on a processor, a computer-readable medium, and a processor. BACKGROUND

[0003] It is known that a control system for a motor vehicle is designed to control one or more vehicle subsystems. US 7,349,776 B2 discloses a vehicle control system comprising a variety of subsystem controls, including an engine management system, a transmission control, a steering control, a brake control, and a suspension control. The subsystem controllers are each capable of operating in a variety of subsystem functions or configuration modes. The subsystem controls are connected to a vehicle mode control, which directs the subsystem controls to assume a required operating mode to provide a range of driving modes for the vehicle. Each of the driving modes corresponds to a specific driving condition or set of driving conditions, and in each mode, each of the subsystems is set to the operating mode most appropriate for those conditions.These conditions depend on the types of terrain the vehicle can travel over, such as grass / gravel / snow, mud and ruts, rock crawling, sand, and a highway mode called "Special Program Off" (SPO). The vehicle mode control may be referred to as the Terrain Response (TR) (RTM) system or control. The driving modes may also be called terrain modes, terrain reaction modes, or control modes.

[0004] As mentioned above, for each of the driving modes, each of the subsystems is set to the operating mode most suitable for those conditions. The applicant has acknowledged that the particular configuration of a subsystem in a given driving mode may not be optimal for actual conditions, or that a driver may have a particular preference for the way in which one or more of the subsystems are configured in a given driving mode, which differs from the standard configuration corresponding to that driving mode. For example, the sand driving mode may not provide optimal vehicle performance when driving on wet or damp sand compared to dry sand.

[0005] US 2002 / 0029914 A1 discloses a device for controlling the driving speed of a motor vehicle, which has an accelerator pedal that is biased into a rest position in the opposite direction of its actuation and can be moved from the rest position to a neutral position, from where further movement of the accelerator pedal against the spring bias leads to an increase in the drive torque of the motor vehicle's drive system. A device for detecting the deactivated position of the accelerator pedal is connected to a brake force generator and, in the non-functional position of the accelerator pedal, causes the brake force generator to perform a target braking force. To make the device more convenient, the brake force generator alternatively builds up the target braking force in a controlled manner when the accelerator pedal reaches its malfunctioning position and / or reduces the built-up braking force in a controlled manner when the accelerator pedal ceases to be in its malfunctioning position.According to another alternative, the device for detecting the malfunctioning position of the accelerator pedal causes the brake force generator to reduce the specified braking force in accordance with the accelerator pedal movement when the accelerator pedal is moved from the rest position to the neutral position, and vice versa.

[0006] US 2011 0065548 A1 discloses a method for restarting the engine of a vehicle that has stopped on an incline. The method comprises the steps of engaging a gear in a transmission that connects the engine and the vehicle's wheels in a way that allows the vehicle to move, using brake pressure to actuate the wheel brakes and generate a wheel torque that keeps the vehicle stationary on the incline, initiating an engine restart, operating the engine to generate a wheel torque equal to or greater than the wheel torque with a road gradient, and releasing the brake pressure.

[0007] EP 1 800 985 B1 discloses a system for controlling the coasting deceleration of a vehicle, consisting of a motor / generator arranged in the vehicle's drivetrain. A control unit is configured to determine the driver's demand for deceleration while idling, accompanied by an accelerator releasing the accelerator pedal. The control unit is further configured to control the motor / generator so that the vehicle decelerates according to the determined driver demand.

[0008] Finally, DE 10 2016 104 048 A1 discloses an exemplary creep torque selection method, which includes selecting a level of reverse creep torque for a vehicle. This selection is independent of the level of forward creep torque for the vehicle.

[0009] Against this background, the present invention was conceived. Embodiments of the invention may provide a device, a method, or a vehicle that solves the problems mentioned above. Further objectives and advantages of the embodiments of the invention will become apparent from the following description, claims, and drawings. SUMMARY OF THE INVENTION

[0010] Various aspects and features of the present invention are defined in the claims.

[0011] In an exemplary embodiment, a control system for a motor vehicle is provided, which is configured to: Receiving drive demand information indicating the amount of drive power required from a vehicle's powertrain; Controlling a quantity of drive torque that the drivetrain exerts on one or more road wheels, depending at least partially on information about the drive requirement; Receiving gradient information indicating a gradient of a driving surface; and Receiving speed information that displays the vehicle's speed over ground, wherein the control system is automatically configured to cause a braking system to apply a braking force to one or more of the road wheels in order to substantially prevent the vehicle from rolling backwards depending at least partially on the gradient information and speed information, wherein the control system is configured to adjust the level of braking force applied depending at least partially on the drive requirement information, wherein the control system is configured to adjust the amount of braking force applied depending at least partially on the drive demand information, comprising the control system which is configured to cause the amount of braking force applied to increase progressively as the amount of drive demand decreases.

[0012] Embodiments of the present invention have the advantage that the vehicle's progress in the terrain can be controlled by reference to the driving requirements information, without the need for an additional separate input of the braking request into the system.

[0013] It is understood that some embodiments of the present invention allow the driver to control the vehicle's speed while traversing rocky terrain comfortably using the drive torque demand control, without the driver having to separately control the application of braking force by the braking system. Rather, the control causes the braking system to be automatically activated depending on the amount of driver torque required when encountering an obstacle. This reduces the driver's workload, allowing the driver to focus more attention on steering the vehicle across the terrain.

[0014] Therefore, if a vehicle is in the process of mounting a rock or boulder in a path of the vehicle, and the amount of drivetrain torque applied to one or more drive wheels decreases, the control system automatically increases the amount of braking force applied by the braking system.

[0015] It is understood that in vehicles with four road wheels, each wheel is typically a braking wheel, onto which a braking force can be applied by a braking system, which may be a foundation braking system, for example, a fluid-operated braking system in which fluid-actuated brake pads are brought into contact with brake discs, as is known in engineering. In some four-wheeled vehicles, each wheel may be a drive wheel, onto which a drive torque can be applied by a drivetrain. Such vehicles are generally referred to as all-wheel drive vehicles (known as a "4×4" configuration).Embodiments of the present invention are not limited to all-wheel drive vehicles, and embodiments of the present invention are also suitable for use in vehicles with a different number of road wheels and a different number of drive wheels, such as two drive wheels, for example in a vehicle with four road wheels (known as a '4x2' configuration).

[0016] Optional, wherein the control system is configured to adjust the level of braking force applied depending at least partially on the driving requirements, comprising the control system which is configured automatically and incrementally to apply braking pressure when an accelerator pedal is released.

[0017] The control system can be automatically configured to cause the braking system to apply a braking force to one or more braked wheels to substantially prevent the vehicle from rolling backward when the vehicle speed drops to substantially zero, where the gradient information indicates that the gradient of the driving surface exceeds a predetermined gradient amount, and the drive requirement information indicates that the amount of drive required by the drivetrain is below a predetermined drive requirement amount.

[0018] Optionally, the specified drive requirement amount essentially corresponds to the minimum drive requirement needed to prevent the vehicle from rolling backward on the current driving surface, whereby the specified drive requirement amount is determined at least partially depending on the gradient information.

[0019] Optionally, the predetermined amount of driver drive requirement is essentially zero. The control system may include a drive torque control device. The drive torque control device may be automatically configured to assume the initial state when the driver releases the drive request. The drive torque control device may include preloading means, such as an elastically expandable or compressible preload element, like a spring element. The input device for the drive request may include a conventional accelerator pedal input device, a hand-operated rotary throttle input device, a hand-operated lever device, or another suitable device. Essentially, the driver drive requirement can be indicated as zero when the input device for the drive request is in the initial state.

[0020] Optionally, the control system is configured to adjust the amount of braking force applied depending at least partially on the drive requirement information, comprising the control system to cause the amount of braking force applied to gradually decrease as the amount of drive requirement increases.

[0021] Optional, wherein the control system is configured to adjust the amount of braking force applied depending at least partially on the drive requirement information, comprising the control system to cause the amount of braking force applied to decrease gradually as the amount of drive requirement increases, wherein the amount of braking force depends at least partially on the gradient information and the drive requirement information.

[0022] In some embodiments, the level of braking force can decrease progressively with increasing drive demand, rather than abruptly and in steps.

[0023] Optionally, wherein the control system is configured to adjust the amount of braking force applied, depending at least partially on the drive demand information, further comprising the control system which is configured to cause the amount of braking force applied to gradually decrease to essentially zero as the amount of drive demand increases, wherein the amount of braking force depends at least partially on the gradient information and the drive demand information.

[0024] In some embodiments, the braking force can be gradually reduced to zero as the drive demand increases. This means that when the braking force is reduced, it is done relatively smoothly and progressively, rather than abruptly and in steps. Thus, the braking force is not reduced stepwise to a predetermined value and then abruptly to zero. It should be understood that this does not preclude the possibility that the amount of braking force, which gradually reduces to a non-zero value, remains essentially constant for a certain period and is then gradually reduced to zero.

[0025] Optional, wherein the control system is configured to adjust the amount of braking force applied depending at least partially on the drive demand information, comprising the control system to effect a reduction in the amount of braking force applied as the amount of drive demand increases, wherein the amount of braking force depends at least partially on the gradient information and drive demand information, wherein the control system is configured to maintain a predetermined amount of applied braking force while the vehicle is moving forward when the amount of drive demand is sufficiently high.

[0026] This function has the advantage that, when a wheel of the vehicle drives over a rock or boulder, a lot of the jerking of the vehicle when the wheel protrudes over the rock or boulder, and the amount of driving torque required for further movement, can be significantly reduced.

[0027] It is to be understood that the predetermined amount of applied braking force, which is maintained by the control system during the forward movement of the vehicle, when the amount of drive demand is sufficiently high, can subsequently be gradually reduced to essentially zero.

[0028] Optional, wherein the control system is configured to maintain a predetermined amount of applied braking force while the vehicle is moving forward, comprising the control system that is configured to limit the vehicle speed to a predetermined speed limit.

[0029] In some embodiments, the predetermined amount of applied braking force can be the amount of braking force required to limit the vehicle speed to the predetermined speed limit.

[0030] The control system may include an electronic processor with an electrical input for receiving drive requirement information, gradient information, and velocity information; and an electronic storage device electrically coupled to the electronic processor and containing instructions stored therein. where the processor is configured to access the memory device and execute the instructions stored therein, so that it is operational: Controlling a quantity of drive torque that the drivetrain exerts on one or more road wheels, depending at least partially on information about the drive requirement; automatically cause a braking system to exert a braking force on one or more of the road wheels in order to substantially prevent the vehicle from rolling backward, depending at least partially on gradient and speed information; and to adjust the level of braking force depending, at least partially, on the information regarding the drive requirement.

[0031] In one aspect of the invention for which protection is sought, a vehicle is provided which includes a control system according to a previous claim.

[0032] In a further embodiment, a method for controlling a vehicle is provided, which is implemented by means of a control system, wherein the method comprises: Receiving information about drive demand, indicating the amount of drive power required from a vehicle's powertrain; Control of a quantity of drive torque that the drivetrain exerts on one or more road wheels, depending at least partially on the drive requirement information; Receiving gradient information indicating a gradient of a driving surface; and Receiving speed information that displays the vehicle's speed over ground, wherein the method involves automatically causing a braking system to exert a braking force on one or more of the road wheels to essentially prevent the vehicle from rolling backward, depending at least partially on gradient and speed information, and automatic adjustment of the applied braking force depending at least partially on the drive requirement information, where the automatic adjustment of the amount of braking force applied, depending at least partially on the drive requirement information, includes causing the amount of braking force applied to increase progressively as the amount of drive requirement decreases.

[0033] The procedure may include the braking system automatically applying a braking force to one or more brake wheels to substantially prevent the vehicle from rolling backward when the vehicle speed falls substantially to zero, with gradient information indicating that the gradient of the driving surface exceeds a predetermined gradient quantity, and drive requirement information indicating that the drive quantity requested by the drivetrain is below a predetermined drive requirement quantity.

[0034] Optionally, the specified drive requirement amount essentially corresponds to the minimum drive requirement needed to prevent the vehicle from rolling backward on the current driving surface, the method including determining the specified drive requirement amount depending at least partially on the gradient information.

[0035] Optionally, adjusting the amount of applied braking force depending at least partially on the drive requirement information includes causing a reduction in the amount of applied braking force as the amount of drive requirement increases.

[0036] Optionally, adjusting the amount of braking force applied, which depends at least partially on the drive requirement information, includes causing an increase in the amount of applied braking force when the amount of drive requirement decreases.

[0037] Optionally, adjusting the amount of braking force applied, depending at least partially on the drive demand information, includes causing a reduction in the amount of braking force applied as the amount of drive demand increases, making the amount of braking force dependent at least partially on the gradient information and the drive demand information, wherein the method includes maintaining a predetermined amount of applied braking force while the vehicle is moving forward when the amount of drive demand is sufficiently high.

[0038] Optionally, maintaining a predetermined amount of applied braking force while moving the vehicle forward includes maintaining a sufficient amount of braking force to limit the vehicle speed to a predetermined speed limit.

[0039] In some embodiments, the specified speed limit can be a function of the accelerator pedal position.

[0040] In one aspect of the invention for which protection is sought, a non-volatile, computer-readable carrier medium is provided which carries a computer-readable code for controlling a vehicle in order to carry out the method of another aspect.

[0041] In one aspect of the invention for which protection is sought, a computer program product executable on a processor is provided to implement the method of another aspect.

[0042] In one aspect of the invention for which protection is sought, a computer-readable medium is provided which is loaded with the computer program product of another aspect.

[0043] In one aspect of the invention for which protection is sought, a processor is provided which is configured to implement the method of another aspect or the computer program product of another aspect.

[0044] In one aspect of the invention for which protection is sought, a motor vehicle is provided with a control system that assists a driver in driving a vehicle over rocky terrain by automatically controlling the application of the vehicle's braking system to (1) prevent rolling backward when a driver releases an accelerator pedal while mounting a step-like obstacle, such as a rock, and / or (2) prevent sliding forward when the vehicle mounts the step-like obstacle. Thus, a driver is essentially only required to control the vehicle's accelerator pedal and, in the case of a vehicle not configured for automatic steering, to steer the vehicle. The function of automatic brake control in this manner may be referred to as "creep mode," "one-pedal creep mode," or any other suitable title.The function can be triggered automatically when one or more conditions are met, and / or automatically selected by a user if required. In the case of automatic triggering, in some embodiments the function can be triggered when the control system detects that the vehicle has stopped abruptly because a wheel of the vehicle has struck an obstacle at low speed, whereby the vehicle's backward roll can be prevented essentially immediately by applying the braking system.For example, if the vehicle has come to a standstill and the control system determines that the level of drivetrain torque developed essentially at the moment the vehicle stopped is sufficient to maintain progress across the terrain (relative to the instantaneous slope of the road surface, based on the vehicle's orientation), the control system may determine that a wheel of the vehicle has encountered a step-like obstacle requiring additional drivetrain torque. The control system may then automatically engage single-pedal creep mode. If the vehicle is traveling in the selected single-pedal creep mode and a step-like obstacle is detected, the control system may automatically re-extend the braking system to prevent rolling backward. The single-pedal creep function can only be used at or below a critical speed, such as…must be operated at 6 km / h, 10 km / h or another suitable speed.

[0045] Some embodiments of the invention provide a control system that assists the driver in traversing rocky terrain using a single pedal (accelerator) to control engine torque and braking force. If the vehicle encounters an abrupt step, such as a rock or boulder, the control system applies a braking force to prevent rolling backward without the driver needing to use the brake pedal. The driver then presses the accelerator pedal, and the control system gradually releases the braking force as the drive torque increases, allowing the vehicle to mount the step without rolling backward. A certain amount of braking force is maintained while the vehicle overcomes the step, preventing excessive forward slippage as the vehicle mounts the step.

[0046] This has the advantage that less experienced drivers can traverse rocky terrain with increased vehicle stability, thus reducing the likelihood of excessive jerking. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The present invention will now be described by way of example only with reference to the accompanying drawings, in which: Fig. is a schematic representation of a vehicle according to an embodiment of the present invention; Fig. is a block diagram illustrating a vehicle control system according to an embodiment of the invention, including various vehicle subsystems under the control of the vehicle control system; Fig. is a flowchart that represents a control loop for controlling the vehicle of the embodiment of Fig. 1 represents; Fig. is a flowchart that represents a section of a procedure for controlling the vehicle of the embodiment of Fig. 1 illustrates; Fig. is a flowchart that describes a method for controlling the vehicle of the embodiment of Fig. 1 illustrates; and Fig. is a flowchart that describes another method for controlling the vehicle of the embodiment of Fig. 1 illustrates. DETAILED DESCRIPTION

[0048] Fig. Figure 100 represents a vehicle 100 according to an embodiment of the invention, which is intended to be suitable for off-road use, i.e., for use on terrain other than normal asphalt roads and paved roads. The vehicle 100 has a drivetrain 129 comprising an engine 121 connected to a drivetrain 130 with an automatic transmission 124 controlled by a transmission control unit 124C. The transmission 124 has a transmission mode selector switch 124L, which allows the driver to select the desired transmission mode from Park (P), Drive (D), Neutral (N), and Reverse (R).

[0049] The drivetrain 130 is arranged to drive a pair of front vehicle wheels 111, 112 by means of a front differential 135F and a pair of front drive shafts 118. The drivetrain 130 also includes an auxiliary drivetrain section 131, which is arranged to drive a pair of rear wheels 114, 115 by means of an auxiliary drive shaft 132, a rear differential 135, and a pair of rear drive shafts 139. It is understood that the embodiments of the present invention are suitable for use with vehicles in which the transmission 124 is arranged to drive only one pair of front wheels or only one pair of rear wheels (i.e., front-wheel drive vehicles or rear-wheel drive vehicles), or selectable two-wheel drive / four-wheel drive vehicles, or permanent all-wheel drive vehicles. In the embodiment of Fig. In the first instance, the transmission 124 can be detachably connected to the auxiliary drive section 131 by means of a transfer case 137, thus enabling either two-wheel drive or all-wheel drive. It should be understood that embodiments of the invention may be suitable for vehicles with more than four wheels or fewer than four wheels.

[0050] In the present embodiment, the transfer case 137 can be operated in a high-ratio ("hi") or low-ratio ("lo") configuration, in which a gear ratio between an input shaft and an output shaft is selected to achieve a high or low ratio. The high-ratio configuration is suitable for general road or highway operation, while the low-ratio configuration is better suited for overcoming certain off-road terrain conditions and other low-speed applications such as towing. In some embodiments, the transfer case 137 can be operated in only one gear ratio configuration and not in one of two.

[0051] The vehicle 100 has an accelerator pedal 161, a brake pedal 163, and a steering wheel 181. The steering wheel 181 is supported by a steering column 181SC. The steering wheel 181 has a cruise control selector switch 181C attached to it for activating an on-highway cruise control system 10CC, which is implemented in software by a vehicle central control unit, referred to as the vehicle control unit (VCU) 10, and described in more detail below. The steering wheel 181 is also equipped with a selector switch 181LSP for the slow-speed progress control system for selecting the operation of an LSP control system 10LSP, which may also be referred to as an off-road speed control system or terrain speed control system. The LSP control system 10LSP is also implemented in software by the VCU 10.In addition to the cruise control system 10CC and LSP control system 10LSP, the VCU 10 is configured to implement a Hill Descent Control (HDC) system 10HDC, which limits the maximum vehicle speed when descending a slope by automatically applying a braking (or brake) system 12d ( . Fig. 2) limited, which is described in more detail below. The HDC system 10HDC can be activated via the Human Machine Interface (HMI) module 32.

[0052] The VCU 10 receives a variety of signals from various sensors and subsystems 12 provided on the vehicle 100.

[0053] Fig. Figure 1 is a schematic diagram that further illustrates the operation of the VCU 10. The VCU 10 controls a variety of vehicle subsystems 12, including, but not limited to, an engine management system 12a, a transmission system 12b comprising the transmission 124 and the transmission control unit 124C, an electronic power steering system 12c (ePAS unit), the braking system 12d, and a suspension system 12e. These vehicle subsystems can be considered an initial group of subsystems. Although five subsystems are depicted as being under the control of the VCU 10, in practice a larger number of vehicle subsystems can be integrated into the vehicle and be controlled by the VCU 10.The VCU 10 includes a subsystem control module 14, which supplies control signals via line 13 to each of the vehicle subsystems 12 to initiate the control of the subsystems in a manner appropriate to the driving condition, such as the terrain over which the vehicle is traveling (terrain conditions). The subsystems 12 also communicate with the subsystem control module 14 via signal line 13 to report information about the subsystem's status. In some embodiments, a hydraulically operated power steering system may be provided instead of an ePAS unit 12c.

[0054] The vehicle is configured to be operated by the VCU 10 in one of several predetermined control modes, depending on the mode selected by the driver. For this purpose, a drive mode selector switch in the form of a rotary knob is provided in the switching package 170. In each control mode, the subsystems 12 are instructed to operate in a predetermined subsystem configuration mode suitable for a specific type of terrain.The control modes include a Grass, Gravel, Snow Control Mode (GGS Mode), suitable for driving the vehicle in grass, gravel, or snowy terrain; a Mud, Slip, and Sludge Control Mode (MR Mode), suitable for driving the vehicle in mud and slush; a Rock Crawl / Block Mode (RC Mode), suitable for driving the vehicle in rocky or scree-covered terrain; a Sand Mode, suitable for driving the vehicle in sandy terrain (or deep, soft snow); and a Special Program Off Mode (SP Off Mode or SPO Mode, also known as Highway or "On-Highway" Mode), which provides a suitable compromise or general-purpose mode for all terrain conditions, and especially for driving the vehicle on highways and regular roadways. Many other control modes are also provided, including those disclosed in US2003 / 0200016, the contents of which are hereby incorporated by reference.

[0055] The different terrain types are grouped according to their friction and roughness. For example, it makes sense to group grass, gravel, and snow as terrain with low friction and a smooth surface, and it makes sense to group rocky and scree-covered terrain as terrain with high friction and very high roughness.

[0056] In some embodiments, the VCU 10 can be automatically configured to determine the most suitable driving mode under specific driving conditions. An example of how this can be achieved is explained in more detail to the present applicant in British patent GB2492655, the contents of which are incorporated herein by reference, as mentioned above.

[0057] In the present embodiment, the user determines the subsystem control mode in which the subsystems are to be operated by selecting a desired system control mode (operating mode). The HMI module 32 comprises a screen (not shown) and a user-friendly switchpack 170. The switchpack 170 allows the user to select the desired subsystem control mode. A selector switch module 20 of the VCU 10 receives a signal 170S from the switchpack 170, as shown in Fig. Figure 2 shows the selected control mode. The selector switch transmits the selected control mode to the subsystem control unit 14 via subsystem signal line 30.

[0058] It is understood that the subsystem control unit 14 itself can directly control the vehicle subsystems 12a-12e via the signal line 13, or alternatively, each subsystem can be controlled by its own associated intermediate control unit (not shown in the diagram). Fig. (2 shown) can be equipped to control the respective subsystem 12a-12e. In the latter case, the subsystem controller 14 can only output the identity of the selected subsystem control mode to each subsystem 12a-12e, instead of executing the actual control steps for the subsystems. The intermediate controller(s) can, in practice, form an integral part of the main subsystem controller 14.

[0059] When the user selects RC mode, the VCU 10 is configured to allow a driver to control the application of drive torque and braking torque to the wheels 111, 112, 114, 115 of the vehicle 100 by means of a single input control, in the present embodiment the accelerator pedal 161, to cause the vehicle 100 to creep over an obstacle that has a relatively abrupt incline, such as a boulder.

[0060] It is assumed that the system of the invention is embodied in the example VCU 10; however, it is assumed that the system is not limited to being contained in a single processor or a single controller, and that the various functions can be distributed across two or more controllers. It is understood that the processor is associated with a memory containing a readable code that is issued so that the controller can perform the method of the invention. To implement this single-pedal creep function, the VCU 10 monitors the gradient of the road surface over which the vehicle 100 is traveling, with respect to speed information in the form of a vehicle reference speed signal Sv, which is received from a brake controller belonging to the brake system 12d, and a signal indicating gradient information, referred to as the gradient signal 11GS, which is received from a gradient sensor 11G.is received, and an accelerator pedal signal 161S, which indicates the position of the accelerator pedal in relation to a range of its permissible travel. The accelerator pedal signal 161S is a measure of the driving request information.

[0061] Regarding the Fig. This is a simplified version of the procedure performed by the VCU 10.

[0062] With reference to Fig. The VCU 10 monitors the accelerator pedal position 310, which indicates the amount of drive torque requested by the driver for the vehicle's powertrain. The VCU 10 also continues to monitor the gradient 320 of the surface over which the vehicle 100 is traveling and adjusts the braking force 330 applied by the braking system 12d to prevent the vehicle 100 from rolling backwards in the opposite direction. The VCU 10 continues to perform these steps iteratively while the single-pedal creep function is activated to ensure the vehicle does not roll backwards.

[0063] With reference to Fig. The VCU 10 receives drive requirement information 410, for example from the accelerator pedal position 310, and is operational to control the drive torque 420 applied to the wheels of the vehicle 100. The VCU 10 then adjusts the braking force 430 at the wheels of the vehicle 100 to ensure forward movement is possible while largely preventing the vehicle 100 from rolling backward. The VCU 10 continues to perform these steps iteratively while the single-pedal creep function is activated to ensure that the vehicle does not roll backward.

[0064] The in the Fig. The described procedures continue to operate simultaneously and ensure that the progress desired by the vehicle user can be achieved, while largely preventing the vehicle from rolling backward.

[0065] Fig. is a flowchart that describes the operation of vehicle 100 of an embodiment of the Fig. illustrated.

[0066] At step 510, the vehicle 100 operates with the single-pedal creep function, which is activated by a driver. It should be understood that the single-pedal creep function can also be referred to as "creep mode". The transmission 124 is in forward driving mode D.

[0067] In step 520, the driver receives the drive demand information from the VCU 10 via an accelerator pedal input derived from accelerator pedal position 310. The drive demand information is analogous to the amount of drive power the driver requests from the vehicle's drivetrain.

[0068] At step 530, gradient information is received from the VCU 10, as indicated by the gradient signal 11GS. The gradient information is representative of the gradients of the terrain that vehicle 100 is currently traversing.

[0069] In step 540, the level of braking force exerted by the vehicle's braking system on one or more wheels or axles is set based on the drive requirement information received in step 520 and the gradient information received in step 530. The level of braking force is determined to essentially prevent the vehicle from rolling backward, i.e., from moving in a direction opposite to the one selected by the driver via the transmission.

[0070] At step 550, the VCU determines whether the vehicle is moving forward. If the vehicle is not moving forward, the process returns to step 520. If the vehicle is moving forward, the process continues with step 560.

[0071] In step 560, the braking force applied to one or more wheels or one or more axles of the vehicle 100 is essentially maintained at the same level to ensure further forward movement of the vehicle.

[0072] In step 570, the drive demand information is compared to a threshold value to determine whether the vehicle's driver is requesting an increase in vehicle speed via the accelerator pedal input. If the drive demand is not greater than the threshold value, the process returns to step 520 and continues with the loop. If the drive demand information is greater than the threshold value, the process continues with step 580.

[0073] At step 580, the braking force applied to one or more wheels or one or more axles of the vehicle 100 is essentially reduced to zero in order to continue the forward movement of the vehicle 100 and increase the speed as requested by the driver via the accelerator pedal input.

[0074] At step 590, the single-pedal creep function is automatically deactivated because the vehicle's drive system has requested that the vehicle's speed rise above the threshold, and such a rollback of the vehicle is no longer likely.

[0075] If the VCU 10 detects that the vehicle 100 has come to a standstill due to the presence of an obstacle in its path, which involves a relatively abrupt incline, the VCU 10 automatically activates the single-pedal creep function. Alternatively, the single-pedal creep function (step 510) can be activated by a driver by selecting the function from a menu accessible via the HMI module 32. In some embodiments, the single-pedal creep function can only be activated by a driver when the vehicle is essentially stationary.

[0076] It is understood that when the single-pedal creep function is activated (step 510), the vehicle 100 is automatically configured to apply braking force to the wheels 111, 112, 114, 115 of the vehicle 100 in order to prevent the vehicle 100 from rolling backward against the direction of travel. It is understood that in the present embodiment, the direction of travel is determined by reference to the selected transmission mode. Thus, if the transmission 124 is in a mode corresponding to forward travel, such as D-mode, then reverse movement is considered a direction opposite to the forward direction of travel in D-mode.

[0077] The VCU 10 is configured to determine that the vehicle 100 has come to a standstill due to an obstacle in its path if the vehicle 100 comes to a standstill with the accelerator pedal 161 depressed at a position (step 520) where forward movement of the vehicle 100 would be expected for the prevailing slope of the road surface (see step 530, determined by reference to the gradient signal 11GS). Thus, the VCU 10 determines that the amount of drivetrain torque developed by the drivetrain 129 is insufficient to allow the vehicle 100 to progress across the terrain and causes the application of braking force to prevent it from rolling backward (step 540).In the present embodiment, the VCU 10 determines a minimum amount of drive demand (step 520) required to move the vehicle 100 forward across the terrain, based on the prevailing slope of the road surface (step 530), this minimum amount of drive demand being referred to as a preset drive demand. If the amount of drivetrain torque to be developed is less than this preset drive demand, the VCU 10 causes braking force to be applied to prevent rolling backward (540).

[0078] In the present embodiment, the VCU 10 is configured to cause the braking system 12d to develop a brake pressure P1 that depends on the gradient of the road surface, which is determined by the VCU 10 when the vehicle 100 comes to a standstill. It is understood that the value of P1 is higher for steeper gradients than indicated by the gradient signal 11GS.

[0079] With the brake system 12d engaged, the VCU 10 monitors the accelerator pedal position 161 based on the accelerator pedal position signal 161S (step 520). As the amount of drivetrain torque requested by the driver increases (determined by the pedal position signal 161S), the VCU 10 progressively reduces the braking force applied by the brake system 12d (by reducing the brake fluid pressure), while ensuring that sufficient braking force is maintained to prevent the vehicle 100 from rolling backward (step 540). The VCU 10 is configured to allow the brake pressure to be reduced from the first predefined pressure value P1 to a second predefined pressure value P2, which is also dependent on the gradient of the road surface, determined by reference to the prevailing value of the gradient signal 11GS (step 530).If the drivetrain torque is sufficient to overcome the braking force with the brake pressure substantially at value P2, vehicle 100 begins mounting the obstacle. The value of P2 is arranged such that it is low enough to allow the vehicle drivetrain 129 to cause vehicle 100 to mount the obstacle, but high enough to prevent vehicle 100 from bouncing forward after mounting the obstacle.

[0080] It is understood that when the driver reduces the required torque by releasing the accelerator pedal 161 (step 570), the VCU 10 is configured to gradually increase the brake pressure back to a value P1, which is repeatedly calculated based on the gradient value indicated by the gradient signal 11GS, in order to prevent downshifting (step 540). It is understood that the feature of the VCU 10 automatically applying braking force when the accelerator pedal 161 is released has the advantage of reducing the driver's workload when approaching an obstacle.

[0081] As mentioned above, the VCU 10 is configured such that the second preset pressure value, P2, is determined to be sufficient to reduce forward slippage when the vehicle 100 encounters the object and continues moving forward, while allowing the forward movement of the vehicle 100 (step 550) without excessive additional drivetrain torque to overcome the braking force specified by the braking system 12d. Maintaining the braking force when encountering an obstacle, and thus reducing forward jerk, has the advantage of improving vehicle stability when overcoming obstacles in the vehicle 100's path. The preset brake pressure values, P1 and P2, can be considered corresponding preset braking force amounts, which are the braking force amounts generated by these brake pressure values.

[0082] In the present embodiment, the VCU 10 is configured to monitor the vehicle speed and attempt to limit it to a predetermined speed limit, where the predetermined speed limit is a function of the accelerator pedal position. If an increase in vehicle speed is observed as a result of decreasing resistance to forward motion, the VCU 10, if necessary, increases the braking force applied by the brake system 12d to maintain the vehicle speed substantially equal to the predetermined speed limit for the respective accelerator pedal position.

[0083] However, if the driver depresses the accelerator pedal 161 by an amount sufficient to cause the vehicle 100 to accelerate, so that the vehicle speed exceeds a predetermined maximum speed value when the single-pedal creep function is in operation (step 570), the VCU 10 is configured to disable the single-pedal creep function (step 590). In the present embodiment, the predetermined maximum speed value is 6 km / h, although other values ​​may be useful in some embodiments.

[0084] When the VCU 10 deactivates the single-pedal creep function, the VCU 10 gradually reduces the brake pressure in the brake system 12d to a value corresponding to the current position of the brake pedal 163 (step 580).

[0085] It is understood that the braking system 12d reacts as usual to the pressing of the brake pedal 163, regardless of whether the single pedal creep function is active or not.

[0086] Fig. is a flowchart that describes the operation of vehicle 100 of the embodiment of Fig. 1 illustrates.

[0087] In step S101, vehicle 100 operates with VCU 10 in RC driving mode, with the single-pedal creep function activated by a driver 510. It should be understood that the single-pedal creep function can also be referred to as "creep mode". The transmission 124 is in forward driving mode D.

[0088] At step S103, the VCU 10 checks whether the vehicle 100 is moving in the direction corresponding to the selected transmission mode, in this example the forward direction, since forward driving mode D is selected. If step S103 determines that the vehicle is moving forward, the VCU 10 continues at step S101; otherwise, the VCU 10 continues at step S105.

[0089] At step S105, the VCU 10 activates the brake system 540, 12d by causing the brake fluid pressure in brake system 12d to reach an initial pressure value P1. The value of P1 is calculated based on the gradient of the driving surface 530, which is determined by reference to the gradient signal 11GS.

[0090] In step S107, the VCU 10 checks the position of the accelerator pedal 161 using the accelerator pedal position signal 161S, 520. As the powertrain torque requested by the driver increases by 520, the VCU 10 reduces the brake pressure P, 540 from the brake system 12d to a second pressure value P2, which is calculated as a function of the gradient signal 11GS and the accelerator pedal position signal 161S.

[0091] At step S109, the VCU 10 determines whether vehicle 100 550 is moving forward, relative to the vehicle speed signal Sv. If vehicle 100 is not moving forward, the VCU 10 continues at step 520, S107. If vehicle 100 is moving forward, the VCU 10 continues at step 560, S111.

[0092] In step S111, the VCU 10 causes the brake system 12d to apply further brake pressure 560 at a value P2, which is determined according to the gradient signal 11GS and the accelerator pedal position signal 161S. The value of P2 is determined by the VCU 10 with reference to a database that provides values ​​of P2 as a function of the gradient signal 11GS and the accelerator pedal position signal 161S. It is understood that in the present embodiment, the database is populated with values ​​that were empirically determined during a calibration procedure, which can be carried out, for example, by field tests.

[0093] At step S113, the VCU 10 checks whether the vehicle speed (as indicated by the speed signal Sv) exceeds a predetermined value. In the present embodiment, as mentioned above, the predetermined value is essentially 6 km / h, although other values ​​may be useful in some alternative embodiments. If the vehicle speed does not exceed 6 km / h, the VCU 10 proceeds to step S111. If the vehicle speed exceeds 6 km / h, the VCU 10 proceeds to step S115.

[0094] At step S115, the VCU 10 prepares to terminate the single-pedal creep function 590 and controls a gradual decrease in brake pressure to a value corresponding to the current position of the brake pedal 163. If the brake pedal 163 is not depressed, the VCU 10 causes a gradual reduction in brake pressure to a value corresponding to a base brake pressure 580, which in some embodiments is a value essentially equal to atmospheric pressure. Once the brake pressure has been reduced to the value corresponding to the current position of the brake pedal 163, the single-pedal creep function is automatically terminated by the VCU 10.

[0095] It is understood that when the single-pedal creep function is in operation and the VCU 10 controls a reduction or increase of the brake pressure 540, the rate of reduction and / or the rate of increase may depend, at least partially, on the gradient of the driving surface 530. In some embodiments, it is particularly advantageous that the rate of increase of the brake pressure increases with increasing gradient, since the increased gravitational force causes the vehicle 100 to roll backward. Thus, if the vehicle 100 is in RC driving mode with the single-pedal creep function inactive and the vehicle 100 encounters an obstacle that causes the vehicle 100 to stop, or if the accelerator pedal 161 is released when the single-pedal creep function is active, the rate at which the braking force is applied to prevent rollback may increase with increasing gradient, relative to the gradient signal 11GS.

[0096] It is understood that the braking force requested by the user of the vehicle via the position of the brake pedal, or automatically applied by the system in response to the position of the accelerator pedal, can be applied to the brake wheel by applying a braking torque by an electric motor, possibly in the form of regenerative braking, instead of or in combination with the vehicle's foundation.

[0097] It is understood that when discussing brake pressure, the braking system could apply a braking force as a negative torque through an electric motor or similar device to generate a force equivalent to the specified brake pressure or braking pressure value at the respective wheel or axle. Such a braking force can be applied by one or more electric motors, one or more elements of the foundation braking system, or a combination of both, through methods such as brake mixing.

[0098] Vehicles that combine one or more electric motors with an internal combustion engine are called hybrid electric vehicles (HEVs). Plug-in hybrid electric vehicles (PHEVs) are a subset of HEVs and have the ability to charge their energy storage devices using grid electricity; as such, they generally have larger energy storage capacities. Battery electric vehicles (BEVs) include one or more electric motors but no internal combustion engine and therefore must be charged using grid electricity. Each of the one or more electric motors can be assigned to a single wheel or axle of the vehicle.It should be noted that the drive power required by the powertrain, as defined by the position of the accelerator pedal in such HEVs, PHEVs or BEVs, is supplied by one or more wheels or one or more axles of the vehicle by the one or more electric motors, the internal combustion engine or a combination of both.

[0099] It is understood that the embodiments described above serve only as examples and not to limit the invention, the scope of which is defined in the attached claims.

[0100] Throughout the description and claims of this specification, the words "include" and "contain" and variations of the words, for example "comprise" and "encompass", are means "including but not limited to", and are not intended to exclude (and not exclude) any other units, additives, components, whole numbers or steps.

[0101] Throughout this specification, the singular includes the plural unless the context requires otherwise. In particular, when the indefinite article is used, the specification is to be understood as considering both plurality and singularity unless the context requires otherwise.

[0102] Features, integers, characteristics, compounds, chemical units or groups described in connection with a particular aspect, embodiment or example of the invention are to be understood as applicable to any other aspect, embodiment or example described herein unless they are inconsistent therewith.

[0103] The reader is hereby made aware of all papers and documents submitted in connection with this application at the same time as or prior to this specification and which are publicly available with this specification, and the contents of all such papers and documents are incorporated herein by reference.

Claims

[1] A control system (10LSP) for a motor vehicle that is configured to: Receiving propulsion demand information (410) indicating a quantity of propulsion required by a powertrain (129, 130) of the vehicle (100); Controlling a quantity of drive torque exerted by the drive train (129, 130) on one or more road wheels, depending at least partially on the drive requirement information; Receiving gradient information indicating a gradient of a driving surface (530); and Receiving speed information that displays the vehicle's speed over ground, wherein the control system is configured to automatically cause a braking system (12d, 540) to apply a braking force (330, 430) to one or more of the road wheels while the single-pedal creep function (590) is active, in order to substantially prevent the vehicle (100) from rolling backward, depending at least partially on the gradient information and speed information, wherein the control system is configured to adjust the level of the applied braking force (330) depending at least partially on the drive requirement information (410), wherein the control system is configured to adjust the amount of braking force (330, 430) applied depending at least partially on the drive requirement information (410), includes that the control system is configured to automatically and gradually apply braking force (330, 430) when an accelerator pedal (161) is released, wherein the control system is configured to disable the single-pedal creep function (590) in response to exceeding a vehicle speed threshold (100). [2] Control system according to claim 1, which is automatically configured to cause the braking system (12d) to exert a braking force (330, 430) on one or more road wheels to substantially prevent the vehicle (100) from rolling backward when the vehicle speed drops substantially to zero, wherein the gradient information indicates that the gradient of the road surface (530) exceeds a predetermined gradient quantity, and the drive requirement information (410) indicates that the quantity of drive required by the drive train (129, 130) is below a predetermined drive requirement quantity. [3] Control system according to claim 2, wherein the predetermined drive requirement amount essentially corresponds to the minimum required drive requirement to prevent the vehicle (100) from rolling backward on an immediate driving surface, wherein the predetermined drive requirement amount is determined at least partially depending on the gradient information. [4] Control system according to a preceding claim, wherein the control system is configured to adjust the amount of braking force (330, 430) applied depending at least partially on the drive requirement information (410), comprising the control system which is configured to cause the amount of applied braking force (330) to decrease stepwise as the amount of drive requirement increases. [5] Control system according to a preceding claim, wherein the control system is configured to adjust the amount of braking force (330, 430) applied depending at least partially on the drive requirement information (410), comprising the control system configured to cause the amount of applied braking force (330) to decrease progressively with increasing amount of drive requirement, wherein the amount of braking force (330, 430) depends at least partially on the gradient information and the drive requirement information (410). [6] Control system according to claim 5, wherein the control system is configured to adjust the amount of braking force (330, 430) applied depending at least partially on the drive requirement information (410), further comprising the control system which is configured to cause the amount of applied braking force (330) to gradually decrease to essentially zero as the amount of drive requirement increases, wherein the amount of braking force (330, 430) depends at least partially on the gradient information and the drive requirement information (410). [7] Control system according to claim 5 or claim 6, wherein the control system is configured to adjust the amount of braking force (330, 430) applied depending at least partially on the drive requirement information (410), further comprising the control system which is configured to cause the amount of applied braking force (330) to decrease gradually as the amount of drive requirement increases, wherein the control system is configured to maintain a predetermined amount of applied braking force (330) while the vehicle (100) is moving forward when the amount of drive requirement is sufficiently high. [8] Control system according to claim 7, wherein the control system is configured to maintain a predetermined amount of applied braking force (330, 430) while the vehicle (100) is moving forward, comprising the control system which is configured to limit the vehicle speed to a predetermined speed limit. [9] Control system according to a preceding claim, comprising an electronic processor with an electrical input for receiving drive requirement information (410), gradient information and velocity information; and an electronic storage device electrically coupled to the electronic processor and comprising instructions stored therein, wherein the processor is configured to access the storage device and execute the instructions stored therein, so that it is operational: Controlling a quantity of drive torque exerted by the drive train (129, 130) on one or more road wheels, depending at least partially on the drive requirement information; automatically cause a braking system (12d, 540) to exert a braking force (330, 430) on one or more of the road wheels in order to substantially prevent the vehicle (100) from rolling backward, depending at least partially on the gradient and speed information; and to adjust the level of braking force (330, 430) depending at least partially on the information regarding the drive requirement. [10] Control system according to one of the preceding claims, wherein the braking system (12d, 540) comprises a foundation braking system. [11] Control system according to one of the preceding claims, wherein the braking system (12d, 540) comprises an electric motor. [12] Vehicle (100) comprising a control system (10L) according to a preceding claim. [13] Method for controlling a vehicle (100) implemented by means of a control system, the method comprising: Receiving information about the drive demand indicating a quantity of drive required from a drive train (129, 130) of the vehicle (100); Controlling a quantity of drive torque exerted by the drive train (129, 130) on one or more road wheels, depending at least partially on the drive requirement information (410); Receiving gradient information indicating a gradient of a driving surface (530); and Receiving speed information that displays the vehicle's speed over ground, wherein the method comprises: automatically causing a braking system (12d, 540) to exert a braking force (330, 430) on one or more of the road wheels to substantially prevent the vehicle (100) from rolling backward, depending at least partially on the gradient information and speed information, while the single-pedal creep function (590) is active, and automatic adjustment of the level of applied braking force depending at least partially on the information on the drive requirement, wherein the automatic adjustment of the amount of braking force (330, 430) applied depending at least partially on the driving requirement information includes the automatic and progressive increase of the amount of applied braking force (330) when releasing an accelerator pedal (161), the procedure further includes: deactivating the single pedal creep function (590) in response to exceeding a threshold value of the vehicle speed (100). [14] Method according to claim 13, comprising the automatic application of a braking force (330, 430) to the one or more brake wheels by the braking system (12d, 540) to substantially prevent the vehicle (100) from rolling backward when the vehicle speed falls substantially to zero, wherein the gradient information indicates that the gradient of the driving surface (530) exceeds a predetermined gradient quantity, and the drive requirement information (410) indicates that the drive quantity required by the drive train (129, 130) is below a predetermined drive requirement quantity. [15] Method according to claim 14, wherein the predetermined amount of drive requirement essentially corresponds to the minimum required drive requirement to prevent the vehicle (100) from rolling backward on the current driving surface, wherein the method comprises determining the predetermined amount of drive requirement as a function of at least part of the gradient information. [16] Method according to any one of claims 13 to 15, wherein adjusting the amount of applied braking force (330) as a function of at least part of the drive requirement information (410) comprises causing a reduction in the amount of applied braking force (330) with increasing amount of drive requirement. [17] Method according to any one of claims 13 to 16, wherein adjusting the amount of applied braking force (330) as a function of at least partially the drive requirement information (410) causes a reduction in the amount of applied braking force (330) as the drive requirement increases, wherein the amount of braking force (330, 430) depends at least partially on the gradient information and the drive requirement information (410), wherein the method comprises maintaining a predetermined amount of applied braking force (330) when moving the vehicle (100) forward when the amount of drive requirement is sufficiently high. [18] Method according to claim 17, wherein maintaining a predetermined amount of applied braking force (330, 430) during the forward movement of the vehicle (100) comprises maintaining a sufficient amount of braking force (330, 430) to limit the vehicle speed to a predetermined speed limit. [19] Non-volatile, computer-readable carrier medium with a computer-readable code for controlling a vehicle (100) for carrying out the method according to any one of claims 13 to 18. [20] A computer program product executable on a processor to perform the method according to any one of claims 13 to 18. [21] Processor arranged to perform the method according to any one of claims 13 to 18 or the computer program product according to claim 20.

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