Control system and method for controlling a vehicle

Abstract

It controls at least one vehicle subsystem and manages the dynamic movement of the vehicle. [Solution] The control system 1 is configured to select one of a plurality of subsystem control modes in response to the determination of the type of terrain on which the vehicle 5 is traveling. Each of the plurality of subsystem control modes defines one or more configurable control parameters for controlling the operation of at least one vehicle subsystem 3. The control system is configured to determine the type of terrain on which the vehicle is traveling based on at least one terrain indicator parameter. Depending on the determined terrain type, one of the plurality of subsystem control modes is selected and configured to set one or more configurable control parameters in the selected subsystem control mode based on at least one terrain indicator parameter.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a control system and method for controlling a vehicle. More specifically, but not limited thereto, the control system and method are suitable for a control system that controls at least one vehicle subsystem to control the dynamic behavior of the vehicle. Aspects of the present invention also relate to a vehicle.

BACKGROUND ART

[0002] It is known to provide a control system for controlling the operation of one or more vehicle subsystems provided in a vehicle. A plurality of subsystem control modes may be defined to control the operation of the vehicle subsystems. The subsystem control modes may be associated with specific driving conditions or terrain types. The control system is configured to switch the subsystem control modes according to the current situation. Subsystem control modes may be defined for a wide range of driving conditions, for example to account for variations due to terrain type. However, constant changes of the subsystem control modes may be perceived as uncomfortable by the user. Furthermore, manual operation of the system may become excessively complicated.

[0003] An object of the present invention is to overcome one or more drawbacks associated with the prior art.

SUMMARY OF THE INVENTION

[0004] Aspects and embodiments of the present invention provide a control system, a vehicle and a method as set forth in the appended claims.

[0005] According to an aspect of the present invention, a control system is provided for controlling at least one vehicle subsystem to control the dynamic operation of a vehicle. The control system is configured to select one of a plurality of subsystem control modes based on the determination of the type of terrain on which the vehicle is traveling. Each of the plurality of subsystem control modes defines one or more configurable control parameters for controlling the operation of at least one vehicle subsystem. The control system comprises one or more processors that jointly perform the following processes. Receiving at least one input signal that includes at least one terrain indicator parameter indicating the type of terrain the vehicle is traveling on; Determining the type of terrain the vehicle is traveling on based on at least one terrain indicator parameter; and Select one of several subsystem control modes depending on the determined terrain type. One of the selected subsystem control modes defines one or more control parameters for at least one vehicle subsystem for operation on a determined terrain type. Here, one or more processors are configured to set one or more configurable control parameters in one of a selection of subsystem control modes, depending on at least one terrain indicator parameter.

[0006] The control system is configured to select one of several subsystem control modes. Each subsystem control mode defines one or more configurable control parameters that are set based on at least one terrain indicator parameter. One or more configurable control parameters can be changed to adjust the subsystem control mode. One or more configurable control parameters can be adjusted without changing the selected subsystem control mode. In other words, one or more configurable control parameters are customizable within the selected subsystem control mode. One or more processors can monitor at least one terrain indicator parameter and adjust one or more configurable control parameters in response to changes in at least one terrain indicator parameter. One or more processors may be configured to output control signals for setting one or more configurable control parameters.

[0007] The selected subsystem control mode remains unchanged while setting one or more configurable control parameters in accordance with at least one terrain indicator parameter. Setting one or more configurable control parameters may involve changing or varying one or more configurable control parameters in accordance with the terrain indicator parameter. One or more configurable control parameters may be dynamically adjusted within the selected subsystem control mode. One or more configurable control parameters may be changed within one or more limits defined for the selected subsystem control mode.

[0008] The control system includes one or more controllers, each having at least one electronic processor having an electrical input for receiving input signals, and at least one memory device electrically connected to the at least one electronic processor, in which instructions are stored. The at least one electronic processor is configured to access the at least one memory device and execute the instructions stored therein to control at least one vehicle subsystem and control the dynamic operation of the vehicle. The at least one electronic processor may be configured to receive at least one input signal, including at least one terrain indicator parameter indicating the type of terrain the vehicle is traveling on. The at least one electronic processor may be configured to select one of a plurality of subsystem control modes depending on the determined terrain type. The selected subsystem control mode defines one or more control parameters for at least one vehicle subsystem to operate on the determined terrain type. The at least one electronic processor may also be configured to set one or more configurable control parameters based on at least one terrain indicator parameter in the selected mode of the plurality of subsystem control modes. The at least one electronic processor may be configured to output a control signal for setting one or more configurable control parameters.

[0009] A subsystem control mode may include one or more of the following: general driving control mode; grass / gravel / snow (GGS) control mode; mud and rut control mode; sand control mode; and rock driving control mode. Other subsystem control modes may be defined. For example, a dedicated snow control mode may be defined.

[0010] At least one input signal includes at least one terrain indicator parameter indicating the type of terrain the vehicle is traveling on. The at least one terrain indicator parameter directly or indirectly indicates the type of terrain. The at least one terrain indicator parameter includes, for example, one or more of the following: vehicle rolling resistance; surface friction or coefficient of friction (μ); surface roughness; and the gradient of the road surface on which the vehicle is traveling. The at least one terrain indicator parameter is measured directly by one or more sensors mounted on the vehicle. For example, the at least one terrain indicator parameter may correspond to the vehicle's dynamic driving parameters. Alternatively, or in addition, the at least one terrain indicator parameter may be determined based on signals (or sets of signals) received from one or more sensors mounted on the vehicle.

[0011] One or more sensors may include one or more of the following: one or more wheel speed sensors for measuring the speed of each wheel; a vehicle pitch sensor; a yaw sensor; a longitudinal acceleration sensor; a torque sensor; a gradient sensor; a brake pedal position sensor; an accelerator pedal position sensor; one or more motion sensors or accelerometers; and one or more tire pressure monitoring sensors.

[0012] At least one terrain indicator parameter may include at least one variable that represents the characteristics of the terrain type on which the vehicle is traveling. One or more processors may be collectively configured to compare the variable with a predefined threshold and, based on whether the variable is greater than or less than the predefined threshold, modify one or more configurable control parameters.

[0013] At least one variable may include an estimated rolling resistance. A predefined threshold may be the rolling resistance threshold. One or more configurable control parameters may be modified based on whether the estimated rolling resistance is greater than or less than a predefined rolling resistance threshold. The estimated rolling resistance is used, for example, to distinguish between shallow snow and deep snow. One or more processors determine that the terrain type includes or consists of deep snow terrain based on whether the estimated rolling resistance is greater than the rolling resistance threshold. Conversely, one or more processors determine that the terrain type includes or consists of shallow snow terrain based on whether the estimated rolling resistance is less than the rolling resistance threshold. One or more configurable control parameters may be modified based on whether the terrain type consists of or consists solely of shallow snow terrain or deep snow terrain. This distinction may be made without changing to a different subsystem control mode. For example, while snow control mode or grass / gravel / snow control mode is selected, the configurable control parameters may change.

[0014] At least one variable may include a surface friction estimate. A predefined threshold may be a surface friction threshold. One or more configurable control parameters are modified based on whether the surface friction estimate is greater than or less than a predefined surface friction threshold. The surface friction estimate is used, for example, to distinguish between gravel and wet grass. One or more processors determine whether a terrain type includes or consists of gravel terrain based on whether the surface friction estimate is greater than the rolling resistance threshold. Conversely, one or more processors determine whether a terrain type includes or consists solely of wet grass terrain based on whether the surface friction estimate is less than the rolling resistance threshold.

[0015] At least one variable may include a surface roughness estimate. A predefined threshold may include a surface roughness threshold. One or more configurable control parameters are modified based on whether the surface roughness estimate is greater than or less than a predefined surface roughness threshold. The surface roughness threshold is used, for example, to distinguish between gravel and road (paved surface). One or more processors determine that the terrain type includes or consists of gravel based on whether the surface friction estimate is greater than the surface roughness threshold. Conversely, one or more processors determine that the terrain type includes or consists of roads based on whether the surface roughness estimate is less than the rolling resistance threshold.

[0016] The type of terrain a vehicle is traveling on may be determined based on one or more atmospheric indicator parameters. These parameters indicate the atmospheric conditions at that time. Atmospheric conditions can be indirect indicators of the terrain. One or more atmospheric indicator parameters may be used in addition to one or more terrain indicator parameters to determine the terrain type. One or more atmospheric indicator parameters may include one or more of the following: ambient temperature, measured precipitation (such as rainfall), and relative humidity. One or more atmospheric indicator parameters may be estimated or measured. For example, one or more atmospheric indicator parameters may be measured by sensors mounted on the vehicle. Alternatively, in addition to this, one or more atmospheric indicator parameters may be estimated based on weather forecasts related to the vehicle's geographical location, for example. It will be understood that the terrain type may also be determined without one or more atmospheric indicator parameters. In other words, the terrain type may be determined based on one or more terrain indicator parameters excluding one or more atmospheric indicator parameters.

[0017] At least one of the multiple subsystem control modes may include multiple auxiliary subsystem control modes. Each of the multiple auxiliary subsystem control modes may define one or more modified control parameters for controlling the operation of at least one vehicle subsystem. One or more configurable control parameters are set by selecting one of the multiple auxiliary subsystem control modes. One or more configurable control parameters may be set by selecting different of the multiple auxiliary subsystem control modes. The auxiliary subsystem control modes may include one or more of the following: auxiliary control mode for grassland; auxiliary control mode for sand use; and auxiliary control mode; auxiliary control mode for hard sand; and auxiliary control mode for soft sand.

[0018] Multiple subsystem control modes may include a grassland-gravel-snow (GGS) control mode. The grassland-gravel-snow (GGS) control mode may include multiple auxiliary subsystem control modes. An auxiliary subsystem control mode may include a grassland auxiliary subsystem control mode for driving on terrain types consisting of or comprising grassland. An auxiliary subsystem control mode may include a deep snow auxiliary subsystem control mode for driving on terrain types consisting of or comprising deep snow. An auxiliary subsystem control mode may include a shallow snow auxiliary subsystem control mode for driving on terrain types consisting of or comprising shallow snow. In at least certain embodiments, the control system may be configured to select one auxiliary subsystem control mode, for example, either a deep snow or shallow snow auxiliary subsystem control mode. The auxiliary subsystem control mode is performed within the range of the selected subsystem control mode, i.e., without changing the selected subsystem control mode.

[0019] Multiple subsystem control modes may include a sandy ground control mode. A sandy ground control mode may include multiple auxiliary subsystem control modes. An auxiliary subsystem control mode may include a hard sandy ground auxiliary subsystem control mode for operation on terrain types consisting of hard sandy ground or composed of hard sandy ground. An auxiliary subsystem control mode may include a soft sand auxiliary subsystem control mode for operation on terrain types consisting of soft sandy ground or soft sand. In at least certain embodiments, the control system may be configured to select one auxiliary subsystem control mode, for example, either a hard sand or soft sand auxiliary subsystem control mode. An auxiliary subsystem control mode may be selected within the range of the selected subsystem control modes, i.e., without changing the selected subsystem control mode.

[0020] One or more processors may be collectively configured to determine the probabilities of a plurality of auxiliary subsystem control modes based on at least one terrain indicator parameter. These probabilities of auxiliary subsystem control modes indicate the suitability of each auxiliary subsystem control mode. One of the plurality of auxiliary subsystem control modes is selected based on the determination that the auxiliary subsystem control node probability for that auxiliary subsystem control mode is greater than the probability threshold for the auxiliary subsystem control mode. In at least certain embodiments, the auxiliary subsystem control mode is selected based on the probabilities of a plurality of auxiliary subsystem control modes. One or more processors may be configured to output a selection signal indicating the selected auxiliary subsystem control mode. One or more processors may be collectively configured to output an auxiliary subsystem control mode selection signal indicating the selected auxiliary subsystem control mode.

[0021] One or more processors may be collectively configured to determine subsystem control mode probabilities for each of a plurality of terrain indicator parameters based on at least one terrain indicator parameter. The subsystem control mode probabilities may provide an index indicating the suitability of each subsystem control mode. One or more processors may also be collectively configured to select one of a plurality of subsystem control modes based on the determination that the subsystem control mode probability is greater than a subsystem control mode probability threshold. Subsystem control mode probabilities may be determined for each of the plurality of subsystem control modes. The subsystem control mode probabilities may serve as an index indicating the suitability of each subsystem control mode. Each subsystem control mode probability may be determined based on at least one terrain indicator parameter.

[0022] One of a plurality of subsystem control modes may be selected based on a determination that the probability of that subsystem control mode is greater than a probability threshold for the subsystem control mode. In at least certain embodiments, the subsystem control mode is selected based on the probabilities of a plurality of subsystem control modes. One or more processors may be collectively configured to output a subsystem control mode selection signal indicating the selected subsystem control mode from among the plurality of subsystem control modes.

[0023] In at least certain embodiments, the probability threshold for a subsystem control mode may be greater than the probability threshold for an auxiliary subsystem control mode. Thus, one of the auxiliary subsystem control modes may be selected with a lower probability than the probability required to select one of the subsystem control modes.

[0024] The one or more configurable control parameters may include one or more torque curves for controlling operation of the propulsion system. Alternatively or additionally, the one or more configurable control parameters may include one or more gear shift maps for controlling selection of a drive ratio of the transmission system. Alternatively or further, the one or more configurable control parameters may include one or more front wheel steering maps for controlling the front wheel steering system. Alternatively or further, the one or more configurable control parameters may include one or more brake maps for controlling the brake system. Alternatively or additionally, the one or more configurable control parameters may include one or more suspension height settings for controlling the suspension system. Alternatively or additionally, the one or more configurable control parameters may include one or more differential configurations for controlling the differential system. Alternatively or additionally, the one or more configurable control parameters may include one or more wheel slip thresholds for controlling the traction control system. Alternatively or additionally, the one or more configurable control parameters may include one or more damper settings for controlling the ride comfort control system. Alternatively or additionally, the one or more configurable control parameters may include one or more rear wheel steering maps for controlling the rear wheel steering system.

[0025] According to a further aspect of the present invention, there is provided a vehicle comprising the control system described herein.

[0026] According to a further aspect of the present invention, there is provided a method of controlling at least one vehicle subsystem to control dynamic behavior of a vehicle. The method comprises: determining a terrain type on which the vehicle is traveling based on at least one terrain indicator parameter; selecting one of a plurality of subsystem control modes based on a terrain type for which it is determined that the vehicle is traveling, wherein the one subsystem control mode selected from the plurality of subsystem control modes defines one or more control parameters for at least one vehicle subsystem for operation on the determined terrain type; Here, each of the plurality of subsystem control modes defines one or more configurable control parameters for controlling operation of the at least one vehicle subsystem. The method includes setting one or more configurable control parameters in a selected one of the plurality of subsystem control modes based on at least one terrain indicator parameter.

[0027] According to a further aspect of the present invention, there are provided computer-readable instructions that, when executed by one or more processors, cause the one or more processors to perform the methods described herein.

[0028] Within the scope of the present application, it is explicitly intended that the various aspects, embodiments, examples, and alternatives described in the preceding paragraphs, claims, and / or the following description and drawings, in particular the individual features thereof, may be employed independently or in any combination. That is, all embodiments and / or all features of the embodiments may be combined in any manner and / or combination, so long as such features are not mutually inconsistent. The applicant reserves the right to amend the originally filed claims, or to file new claims in accordance therewith. This includes the right to amend the originally filed claims to be dependent on and / or incorporate any feature of any other claim, even if not originally so claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] One or more embodiments of the present invention will be described below, by way of example only, with reference to the accompanying drawings.

[0030] [Figure 1] Figure 1 shows a schematic diagram of a vehicle equipped with a control system according to an embodiment of the present invention.

[0031] [Figure 2] Figure 2 shows a plan view of the vehicle shown in Figure 1.

[0032] [Figure 3] Figure 3 shows a schematic diagram of a control system for controlling at least one vehicle subsystem according to an embodiment of the present invention.

[0033] [Figure 4A] Figure 4A is a schematic diagram of the vehicle's propulsion system, which can be configured according to terrain index parameters.

[0034] [Figure 4B] Figure 4B is a schematic diagram of the vehicle's transmission system, which can be set according to terrain index parameters.

[0035] [Figure 4C] Figure 4C is a schematic diagram of a vehicle steering system that can be configured according to terrain indicator parameters.

[0036] [Figure 4D] Figure 4D is a schematic diagram of a vehicle's braking system that can be configured according to terrain indicator parameters.

[0037] [Figure 4E] Figure 4E is a schematic diagram of a vehicle suspension system that can be configured according to terrain index parameters.

[0038] [Figure 4F] Figure 4F is a schematic diagram of the vehicle's differential system, which can be configured according to terrain index parameters.

[0039] [Figure 4G]Figure 4G is a schematic diagram of a vehicle traction control system that can be configured according to terrain indicator parameters.

[0040] [Figure 4H] Figure 4H is a schematic diagram of a vehicle damper control system that can be set according to terrain index parameters.

[0041] [Figure 4I] Figure 4I is a schematic diagram of the vehicle's rear-wheel steering system, which can be configured according to terrain index parameters.

[0042] [Figure 5] Figure 5 shows a first block diagram of a method for controlling at least one vehicle subsystem in a grass, gravel, and snow (GGS) control mode according to an embodiment of the present invention.

[0043] [Figure 6] Figure 6 shows a first second block diagram of a method for controlling at least one vehicle subsystem in a sand control mode according to an embodiment of the present invention.

[0044] [Figure 7] Figure 7 is a schematic diagram of a control unit configured to select one of several auxiliary subsystem control modes according to the auxiliary mode selection probability. [Modes for carrying out the invention]

[0045] A control system 1 and method 400 for controlling the operation of at least one subsystem 3(n) of a vehicle 5, according to embodiments of the present invention, will be described with reference to the accompanying drawings. As described herein, the control system 1 comprises a vehicle control unit 7 for controlling the operation of at least one vehicle subsystem 3(n).

[0046] In this specification, Vehicle 5 is described with reference to a coordinate system consisting of a longitudinal axis X, a horizontal axis Y, and a vertical axis Z. Reference symbols in this specification include integer suffixes to distinguish multiple identical components on Vehicle 5. The same suffix applies to related components, for example, components constituting the same subassembly of Vehicle 5. The integer n is used herein to identify a signal or event associated with one of several corresponding features of Vehicle 5.

[0047] As shown in Figure 1, the control system 1 is installed in a vehicle 5 having four wheels 9(1)-9(4). The wheels 9(1)-9(4) consist of first and second front wheels 9(1) and 9(2) located on the front axle, and first and second rear wheels 9(3) and 9(4) located on the rear axle. The vehicle 5 is an automobile, a sports utility vehicle (SUV), or a utility vehicle. As shown in Figures 1 and 2, the vehicle 5 in this embodiment is an automobile. The vehicle 5 is equipped with one or more torque generating devices 11, such as an internal combustion engine (ICE) and / or an electric drive system. The vehicle 5 may be a battery electric vehicle (BEV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), or an internal combustion engine (ICE) vehicle. The front wheels 9(1), 9(2) and / or the rear wheels 9(3), 9(4) may be driven by one or more torque generating devices 11. Vehicle 5 is two-wheel drive, with only the front wheels 9(1)-9(2) being driven. The torque generator 11 includes an internal combustion engine 11 for driving the front wheels 9(1) and 9(2) of vehicle 5. Alternatively, or in addition to this, the internal combustion engine 11 may also drive the rear wheels 9(1) and 9(2) of vehicle 5. Vehicle 5 may also include one or more electric drive units (not shown).

[0048] Figures 1 and 2 show the control system 1 for vehicle 5. Vehicle 5 is suitable for off-road use, i.e., use on terrain other than normal paved roads. The control system 1 controls one or more vehicle subsystems 3(n), including but not limited to the propulsion (or engine) system 3(1), transmission system 3(2), front-wheel steering system 3(3), brake system 3(4), suspension system 3(5), differential system 3(6), traction control system 3(7), ride (damping) system 3(8), and rear-wheel steering system 3(9). The vehicle subsystems 3(n) may be controlled independently of each other, or two or more vehicle subsystems 3(n) may be controlled in combination with each other. The propulsion system 3(1) and transmission system 3(2) together form a powertrain system. Although nine subsystems are shown under the control of the control system 1, in reality, more vehicle subsystems 3(n) may be installed in vehicle 5 and controlled by the control system 1. In this specification, it is stated that a vehicle subsystem 3(n) has individual control units. It will be understood that the control units of multiple vehicle subsystems 3(n) may be integrated, for example, within a centralized control unit.

[0049] The control system 1 includes a vehicle control unit 7. The vehicle control unit 7 shown in Figure 3 includes one controller 110, but it should be understood that this is merely an example. The controller 110 includes processing means 120 and storage means 130. The processing means 120 may be one or more electronic processing devices 120 that operably execute computer-readable instructions. The storage means 130 may be 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 instructions, and the processing means 120 is configured to access the storage means 130 and execute the instructions stored therein. The controller 110 includes input means 140 and output means 150. The input means 140 may include an electrical input 140 of the controller 110. The output means 150 may include an electrical output 150 of the controller 110.

[0050] The vehicle control unit 7 is configured to output a control signal 155 to control one or more of the vehicle subsystems 3(n). The control signal 155 configures the subsystems 3(n) in a manner suitable for the driving conditions of the vehicle 5. The control signal 155 may, for example, configure the vehicle subsystems 3(n) to control the vehicle 5 based on the determination of the type of terrain (hereinafter referred to as terrain type) on which the vehicle 5 is driving. The control signal 155 includes an electrical signal 155 output from the electrical output 150.

[0051] The vehicle control unit 7 receives a plurality of input signals 160 from vehicle sensors 13(n) provided on the vehicle 5. The input signals 160 represent various parameters related to the vehicle's motion and state. The input signals 160 are used to provide, or to calculate, a plurality of terrain index parameters 165(n) that indicate the type of terrain on which the vehicle 5 is traveling. The vehicle control unit 7 is configured to determine an appropriate control strategy for one or more vehicle subsystems 3(n) based on the terrain index parameters 165(n). In this embodiment, the vehicle control unit 7 is configured to classify the terrain into one of the following terrain types: on-road; grass / gravel / snow; mud and ruts; sand; and rocky terrain. The terrain classification can be modified, for example, to reduce or add terrain types.

[0052] The vehicle subsystem 3(n) is controlled based on a selection from among a plurality of subsystem control modes 170(n). Each subsystem control mode 170(n) defines one or more operating parameters of the vehicle subsystem 3(n). The vehicle subsystem 3(n) is controlled based on the selected subsystem control mode 170(n). A plurality of subsystem control modes 170(n) are predefined. As described herein, each of the plurality of subsystem control modes 170(n) corresponds to one or more terrain types. The subsystem control modes 170(n) constitute the vehicle subsystem 3(n). The vehicle control unit 7 is configured to select one of the plurality of subsystem control modes 170(n) based on one or more of a plurality of terrain index parameters 165(n). For each subsystem control mode 170(n), a mode selection probability (weighted) 31(n) is calculated based on the terrain index parameter 165(n). The vehicle control unit 7 selects one of the subsystem control modes 170(n) based on the calculated mode selection probability. The vehicle control unit 7 compares the mode selection probabilities for each subsystem control mode 170(n) to determine the subsystem control mode 170(n) suitable for the current operating conditions. For example, the vehicle control unit 7 integrates the mode selection probabilities 31(n) for each subsystem control mode 170(n). This integration determines a positive difference between the calculated mode selection probability 31(n) for the currently selected subsystem control mode 170(n) and the calculated mode selection probabilities 31(n) for each of the other subsystem control modes 170(n). If the integrated value exceeds a predetermined threshold, or if the current subsystem control mode selection probability 31(n) is zero or less than or equal to the predetermined threshold, the vehicle control unit 7 can change the selected subsystem control mode 170(n).

[0053] Each of the multiple subsystem control modes 170(n) is associated with a corresponding one of several terrain classifications. The subsystem control modes 170(n) include: General driving control mode 170(1); Grass / Gravel / Snow (GGS) control mode 170(2); Mud / Rut Driving Control Mode 170(3); Sand Driving Control Mode 170(4); and Rock Driving Control Mode 170(5). General driving control mode 170(1) is suitable for driving on public roads and, for example, allows the suspension to be set to prioritize ride comfort. Grass / Gravel / Snow (GGS) control mode 170(2) adjusts throttle response and sets the transmission to prioritize traction. Mud / Rut Control Mode 170(3) allows wheelspin to enable driving on muddy terrain. Sand Driving Control Mode 170(4) maps throttle response to maintain momentum on sandy terrain. The rock crawl control mode 170(5) includes setting the throttle map or torque map of the internal combustion engine 11 to perform a rock crawl operation. The rock crawl control mode also includes controlling the transfer case to select a low gear ratio.

[0054] Vehicle 5 is equipped with a plurality of vehicle sensors 13(n) for measuring external variables. Sensors 13(n) are configured to measure the operating parameters of vehicle 5 and output sensor signals 15(n) indicating the measured variables. Sensor signals 15(n) are supplied to the vehicle control unit 7 as input signals 160. Sensor signals 15(n) are electrical signals. In this embodiment, sensors 13(n) are configured to provide continuous (i.e., uninterrupted) indication of the operating parameters. Sensor signals 15(n) provide a quantized representation of the measured operating parameters.

[0055] In this embodiment, the sensors 13(n) include a wheel speed sensor 13(1) for measuring the speed of each wheel 9(1)-9(4); a vehicle pitch sensor 13(2); a yaw sensor 13(3); a longitudinal acceleration sensor 13(4); a torque sensor (or torque estimator) 13(6); a gradient sensor (or gradient estimator) 13(7); a brake pedal position sensor 13(8); an accelerator pedal position sensor 13(9); longitudinal, lateral, and vertical motion sensors 13(10); and a tire pressure monitoring system (TPMS) 13(11). One or more sensors may be provided to measure one or more atmospheric index parameters 185(n). For example, sensor 13(n) includes an ambient temperature sensor 13(5) configured to measure ambient temperature AMT. The wheel speed sensor 13(1) outputs a wheel speed signal 15(1) indicating the measured wheel speed of each wheel 9(1)-9(4). The vehicle pitch sensor 13(2) outputs a vehicle pitch signal 15(2) indicating the measured vehicle pitch angle of the vehicle 5 (i.e., the measured rotation of the vehicle 5 around the horizontal axis Y). The yaw sensor 13(3) outputs a yaw signal 15(3) indicating the measured yaw angle of the vehicle 5 (i.e., the measured rotation of the vehicle 5 around the vertical axis Z). The longitudinal acceleration sensor 13(4) outputs a longitudinal acceleration signal 15(4) indicating the measured longitudinal acceleration of the vehicle 5 (i.e., the acceleration of the vehicle 5 along the longitudinal axis X). The ambient temperature sensor 13(5) outputs an ambient temperature signal 15(4) indicating the measured ambient temperature. The torque sensor 13(6) outputs a torque signal 15(6) indicating the torque (Nm) generated by the internal combustion engine 11 (and / or electric traction motor). The gradient sensor 13(7) outputs a gradient signal 15(7) indicating the measured or estimated gradient of the road surface on which the vehicle 5 is traveling. The brake pedal sensor 13(8) outputs a pedal signal 15(8). This indicates the position of the brake pedal (not shown), for example, the degree to which the brake pedal is depressed. The accelerator pedal sensor 13(9) outputs an accelerator pedal signal 15(9). This outputs an accelerator pedal signal 15(9) that indicates the position of the accelerator pedal (not shown), for example, the degree to which the accelerator pedal is depressed.The vertical, horizontal, and vertical motion sensors 13(10) output motion signals indicating the motion of the vehicle 5 along the respective reference axes X, Y, and Z. The vehicle 5 may be equipped with an inertial measurement unit (not shown). The inertial measurement unit may, for example, include one or more accelerometers. One or more of the pitch sensor 13(2), yaw sensor 13(3), vertical accelerometer 13(4), and vertical, horizontal, and vertical motion sensors 13(10) may be incorporated into the inertial measurement unit.

[0056] The friction estimator 17 is provided to estimate the coefficient of friction (μ) of the road surface on which the vehicle 5 is traveling. The coefficient of friction (μ) is estimated, for example, based on the detection of wheel slip events. The road surface roughness estimator 19 is provided to determine the road surface roughness parameter SFR, which quantifies the roughness of the road surface on which the vehicle 5 is traveling. The road surface roughness SFR is defined based on a certain scale, for example, as a percentage (%) of an upper limit. The road surface roughness SFR estimator 19 can quantify the surface roughness SFR, for example, based on signals received from any of the longitudinal, lateral, or vertical motion sensors 13(10). The ambient temperature AMT is measured by the ambient temperature AMT sensor 13(5).

[0057] As described above, the vehicle control unit 7 is configured to select one of several subsystem control modes 170(n) corresponding to the current terrain type. A mode selection probability (weighted) 31(n) is determined for each subsystem control mode 170(n). The mode selection probability 31(n) indicates the likelihood that the associated subsystem control mode 170(n) is suitable for the terrain type on which the vehicle 5 is traveling. The mode selection probability 31(n) may consist of, for example, one or more of the following:

[0058] The probability of selecting a general driving mode 31(1) associated with the general driving control mode 170(1).

[0059] The probability of selecting the grass / gravel / snow (GGS) mode associated with grass / gravel / snow (GGS) control mode 170(2) is 31(2).

[0060] Mud / rut control mode selection probability 31(3) associated with mud / rut control mode 170(3).

[0061] The sand mode selection probability 31(4) is associated with sand control mode 170(4).

[0062] The rock crawl mode selection probability 31(5) associated with rock crawl control mode 170(5).

[0063] The mode selection probability 31(n) is determined based on one or more terrain index parameters 165(n). As described herein, the terrain index parameters 165(n) may be derived from variables measured by sensor 13(n). These variables represent, for example, the operating conditions or states of the vehicle subsystem 3(n). In this embodiment, the mode selection probability 31(n) is also determined based on one or more atmospheric condition indices 185(n). One or more atmospheric condition indices 185(n) include ambient temperature AMT measured by temperature sensor 3(5). For each subsystem control mode 170(n), the mode selection probability 31(n) is calculated. The calculated mode selection probabilities 31(n) are compared to determine which of the plurality of subsystem control modes 170(n) is suitable for the current driving conditions. The mode selection probability 31(n) of the currently selected subsystem control mode 170(n) is compared with each of the other mode selection probabilities (n). In this embodiment, each mode selection probability 31(n) is integrated with respect to time. The integral of the mode selection probability 31(n) for the currently selected subsystem control mode 170(n) is compared with the integrals of each other subsystem control mode (n). The difference between the integrals calculated for the selected subsystem control mode 170(n) and each of the other subsystem control modes 170(n) is calculated. Subsystem control mode 170(n) is changed to one of the other subsystem control modes 170(n) based on the determination that the difference calculated for that subsystem control mode 170(n) is greater than or equal to a threshold.

[0064] The vehicle control unit 7 is configured to select one of a plurality of subsystem control modes 170(n). Each subsystem control mode 170(n) sets up one or more vehicle subsystems 3(n) for the associated terrain type. The subsystem control mode 170(n) can define, for example, one or more control parameters for controlling the operation of at least one vehicle subsystem 3(n). As described herein, the subsystem control mode 170(n) according to this embodiment comprises one or more configurable control parameters CCP(n). One or more configurable control parameters CCP(n) define the operating parameters of the corresponding vehicle subsystem 3(n). The configurable control parameters CCP(n) are modified based on one or more terrain index parameters 165(n). One or more terrain index parameters 165(n) indicate the structure or configuration of the terrain type on which the vehicle 5 is traveling. The configurable control parameters CCP(n) may also be modified, if necessary, based on one or more atmospheric index parameters 185(n). One or more atmospheric index parameters 165(n) indicate ambient conditions such as temperature. One or more atmospheric index parameters 165(n) may provide indirect information about the type of terrain on which the vehicle 5 is traveling. A configurable control parameter CCP(n) reconfigures the vehicle subsystem 3(n) within a range of operating parameters defined by the selected subsystem control mode 170(n). The vehicle subsystem 3(n) is then controlled according to the current terrain type. These changes can be implemented without changing to a different subsystem control mode 170(n).

[0065] One or more configurable control parameters CCP(n) are defined for one or more vehicle subsystems 3(n). The configurable control parameters CCP(n) can be modified to configure the associated vehicle subsystems (3) for operation on the current road or terrain type. Examples of configurable control parameters CCP(n) are provided below. It will be understood that one or more of the configurable control parameters CCP(n) described herein may be omitted.

[0066] The propulsion system 3(1) defines a first configurable control parameter CCP(1) consisting of or encompassing one or more torque curves TC(n). The transmission system 3(2) defines a second configurable control parameter CCP(2), which consists of one or more gear shift maps GM(n) for controlling the drive ratio selection. The front wheel steering system 3(3) defines a third configurable control parameter CCP(3), which consists of one or more front wheel steering maps FWSM(n). The brake system 3(4) defines a fourth configurable control parameter CCP(4), which consists of one or more brake maps BM(n). The suspension system 3(5) defines a fifth configurable control parameter CCP(5), which consists of one or more suspension height settings SC(n). The differential system 3(6) defines a sixth configurable control parameter CCP(6), which consists of one or more differential configurations DC(n), which includes or consists of one or more differential configurations DC(n). The traction control system 3(7) defines a seventh configurable control parameter CCP(7), which includes or consists of one or more wheel slip thresholds STH(n). The ride system 3(8) defines an eighth configurable control parameter CCP(8), which includes one or more damper settings DS(n). The rear wheel steering system 3(9) defines a ninth configurable control parameter CCP(9), which includes or consists of one or more rear wheel steering maps RWSM(n). A configurable control parameter CCP(n) for one or more vehicle subsystems 3(n) may include two or more configurations. In this embodiment, the configurable control parameter CCP(n) associated with each vehicle subsystem 3(n) includes first, second, and third configurations. The first configuration of each configurable control parameter CCP(n) is referred to herein as the default configuration and is associated, for example, with a general driving control mode. The second and third configurations are described herein in relation to the first configuration, for example, to define higher and / or lower operating parameters related to the same vehicle subsystem 3(n).Table A outlines the configurable control parameters CCP(n).

[0067] [Table A]

[0068] The operation of the vehicle control unit 7 will now be explained with respect to the GGS control mode 170(2). The GGS control mode 170(2) sets up one or more vehicle subsystems 3(n) to drive the vehicle on terrain classified as grassland / gravel / snow. The GGS mode selection probability 31(2) is determined based on one or more of the following terrain indicator parameters 165(n). Rolling resistance of vehicle 5 (N) 90; The estimated coefficient of friction (μ) of the road surface on which vehicle 5 is traveling; and Road surface roughness SFR parameter.

[0069] It will be understood that other topographic indicator parameters 165(n) may be used to determine the GGS mode selection probability 31(2). The GGS mode selection probability 31(2) may optionally be determined based on one or more atmospheric indicator parameters 185(n), such as ambient temperature AMT.

[0070] Rolling resistance Frr represents the force resisting the motion of vehicle 5 on the ground surface. On a flat surface (i.e., without gradient), rolling resistance Frr can be calculated using the following formula: [Mathematics 1] Frr=f·m·g Here, Frr is rolling resistance (N); f is the rolling resistance coefficient; m is the vehicle mass (kg); and g is the acceleration due to gravity (9.81 m / s²). 2 )

[0071] The rolling resistance Frr on an inclined surface (gradient α) can be calculated using the following formula. [Math 2] Frr = f·m·g·cos(α) Here: Frr is rolling resistance (N); f is the rolling resistance coefficient; m represents the vehicle mass (kg); g is the acceleration due to gravity (9.81 m / s²). 2 ); and α is the gradient (°).

[0072] The rolling resistance coefficient f is greater on deformable surfaces. For example, the rolling resistance coefficient f is greater on terrain with shallow snow than on terrain with grass. Furthermore, the rolling resistance coefficient f can vary even within the same terrain type. In the case of snow terrain, the rolling resistance coefficient f usually increases as the snow depth increases.

[0073] The GGS control mode 170(2) includes a plurality of configurable control parameters CCP(n). The configurable control parameters CCP(n) define the operating parameters of the vehicle subsystem 3(n). The control system 1 is configured to change the configurable control parameters CCP(n) based on one or more terrain indicator parameters 165(n). The configurable control parameters CCP(n) are changed based on a determination of whether one or more terrain indicator parameters 165(n) indicate that the vehicle 5 is traveling on terrain that includes or consists solely of deep snow (referred to herein as deep snow terrain). Deep snow, as used herein, is changed based on a determination of whether it indicates a predetermined depth (for example, a depth corresponding to the radius of wheels 9(1)-9(4)). Conversely, shallow snow, as used herein, refers to snow with a depth less than a predetermined depth. Other depths may be defined to distinguish between shallow snow and deep snow. The control system 1 determines that the terrain type is deep snow terrain based on one or more terrain indicator parameters 165(n). When GGS control mode 170(2) is selected, the control system 1 determines that the terrain type is deep snow terrain based on the rolling resistance Frr. The rolling resistance threshold RRT is predefined. The rolling resistance threshold RRT is defined as 2300N. The rolling resistance threshold RRT may be less than or greater than 2300N. Other terrain index parameters 165(n) may be used in this determination.

[0074] The terrain type may optionally be determined based on one or more atmospheric index parameters 185(n). One or more atmospheric index parameters 185(n) may be used in combination with terrain index parameters 165(n) to determine the terrain type. In this embodiment, one or more atmospheric index parameters 185(n) include the ambient temperature AMT measured by the ambient temperature sensor 3(5). The control system 1 positively determines that the terrain type is deep snow terrain based on the determination that the ambient temperature AMT is less than the temperature threshold TTH and the rolling resistance Frr is greater than the rolling resistance threshold RRT. Conversely, the control system 1 determines that the terrain type is not deep snow terrain based on the determination that the ambient temperature AMT is greater than the temperature threshold TTH and / or the rolling resistance Frr is less than the rolling resistance threshold RRT. In this embodiment, the temperature threshold TTH is defined as -5°C. The temperature threshold may be less than or greater than -5°C.

[0075] The control system 1 is configured to change one or more of several configurable control parameters CPP(n) based on a positive determination that the terrain type is deep snow terrain. The control system 1 is configured to run (or maintain) one or more configurable control parameters CCP(n) in their default (or standard) settings based on a negative determination that the terrain type is deep snow terrain. Multiple configurable control parameters CCP(n) may be grouped together to form one or more auxiliary subsystem control modes 175(n). One or more auxiliary subsystem control modes 175(n) may be selected within the currently selected subsystem control mode 170(n). The subsystem control mode 170(n) and one or more auxiliary subsystem control modes 175(n) have a hierarchical structure. One or more auxiliary subsystem control modes 175(n) are selectable within subsystem control mode 170(n). As described herein, one or more auxiliary subsystem control modes 175(n) are selected based on one or more terrain indicator parameters 165(n). One or more auxiliary subsystem control modes 175(n) are optionally selected based on one or more atmospheric index parameters 165(n).

[0076] In this example, based on a positive determination that the terrain type is deep snow terrain, auxiliary subsystem control mode 175(1) is selected within GGS control mode 170(2). This is called deep snow auxiliary subsystem control mode 175(1). Deep snow auxiliary subsystem control mode 175(1) is predefined. Alternatively, or in addition to this, auxiliary subsystem control mode 175(2) may be selected based on the determination that the terrain type is shallow snow terrain (hereinafter referred to as shallow snow terrain). This is called shallow snow auxiliary subsystem control mode 175(2). Alternatively, in addition to this, auxiliary subsystem control mode 175(3) may be selected based on the determination that the terrain contains gravel or is composed of gravel. This is called gravel auxiliary subsystem control mode 175(n). When GGS control mode 170(2) is selected, the said or each auxiliary subsystem control mode 175(n) is selectable. It will be understood that with respect to one or more of the other control modes 170(n), one or more auxiliary subsystem control modes 175(n) may be defined. The configurable control parameters CCP(n) related to the vehicle subsystem 3(n) are described below.

[0077] The internal combustion engine 11 constitutes part of the propulsion system 3(1). As schematically shown in Figure 4A, the propulsion system 3(1) includes a propulsion control unit 21 having one or more electronic processors. The propulsion control unit 21 is configured to control the operation of the internal combustion engine 11. The propulsion control unit 21 defines a first configurable control parameter CCP(1) for controlling the operation of the internal combustion engine 11. As described herein, the control system 1 is configured to modify the first configurable control parameter CCP(1) based on one or more terrain index parameters 165(n). The control system 1 may also optionally modify the first configurable control parameter CCP(1) based on one or more atmospheric index parameters 185(n). The first configurable control parameter CCP(1) includes a torque curve TC(n) for the internal combustion engine 11. The propulsion control unit 21 defines a plurality of torque curves TC(n). The torque curves TC(n) are different from each other. For example, the torque curves TC(n) may have different profiles and may vary the supply of maximum torque. The first configurable control parameter CCP(1) is changed by changing the selected torque curve TC(n). The torque curve TC(n) is selected based on one or more terrain indicator parameters 165(n). The propulsion control unit 21 defines the first torque curve TC(1), the second torque curve TC(2), and the third torque curve TC(3). The first torque curve TC(1) represents the default or normal torque curve of the internal combustion engine 11. The first torque curve TC(1) represents the default or normal torque curve for the internal combustion engine 11. The first torque curve TC(1) is selected when the vehicle 5 is operating in the general driving control mode 170(1). The second torque curve TC(2) represents the responsive torque curve for the internal combustion engine 11. The second torque curve TC(2) helps to increase torque supply in response to torque demands. This is suitable for driving on terrain with high surface resistance, such as deep snow or soft sand. The third torque curve TC(3) provides a gentler torque supply in response to torque requirements.This is suitable for driving on terrain with a low coefficient of friction, such as snow, ice, or wet grass, because it facilitates starting while avoiding or reducing wheel spin, thereby improving traction. The torque curve TC(n) is predefined. It will be understood that fewer than three or more torque curves TC(n) may be defined for selection by control system 1.

[0078] The third torque curve TC(3) has a suppressed response and is suitable for road surfaces with a low coefficient of friction. The second torque curve TC(2) has an enhanced response and is suitable for road surfaces with high resistance such as deep snow or soft sand. The control system 1 requests the selection of one of the first, second, and third torque curves TC(1)-TC(3) based on one or more terrain index parameters 165(n). The control signal 155 controls the propulsion system 3(1) to select one of the first, second, and third torque curves TC(1)-TC(3). Based on the determination that GGS control mode 170(2) is selected, the control system 1 is configured to change the first configurable control parameter CCP(1) as follows.

[0079] Based on the determination that the terrain type is grassland, the third torque curve TC(3) is selected.

[0080] Based on the determination that the terrain type is gravel, the first torque curve TC(1) is selected.

[0081] In response to the determination that the terrain type is gravel, a third torque curve TC(3) is selected.

[0082] Based on the determination that the terrain type is shallow snow, the first torque curve TC(1) is selected.

[0083] Based on the determination that the terrain type is hard sandy ground, the first torque curve TC(1) is selected.

[0084] Based on the determination that the terrain type is soft sand, the second torque curve TC(2) is selected.

[0085] The process of selecting one of the first, second, or third torque curves TC(1)-TC(3) is performed independently of the selected subsystem control mode 170(n). Therefore, the selected torque curve TC(n) can be changed based on one or more terrain indicator parameters 165(n) without changing the subsystem control mode 170(n).

[0086] As schematically shown in Figure 4B, the transmission system 3(2) comprises a transmission control unit 31 and a transmission 33. The transmission 33 is drastically connected to the internal combustion engine 11 and is operable to selectively engage one of a plurality of drive ratios. The drive ratios typically consist of a plurality of forward drive ratios, reverse drive ratios, and neutral (or disengaged) drive ratios. At least one transmission control unit 31 comprises one or more electronic processors. At least one transmission control unit 31 is configured to control the operation of the transmission 33.

[0087] The transmission control unit 31 defines a second configurable control parameter CCP(2) for controlling the operation of the transmission 33. As described herein, the control system 1 outputs a control signal 155 to set the second configurable control parameter CCP(2) based on one or more terrain indicator parameters 165(n). The second configurable control parameter CCP(2) includes a gear shift map GM(n) for controlling the selection of the drive ratio by the transmission 31. Multiple gear shift maps GM(n) are defined. The second configurable control parameter CCP(2) is modified by changing the selected gear shift map GM(n). Each gear shift map GM(n) defines an upshift pattern and / or downshift pattern for the transmission 33. The gear ratio map GM(n) may define, for example, the relationship between each drive ratio and driving parameters of the vehicle 5, such as torque (Nm) and / or speed (km / h). The gear ratio map GM(n) may use other parameters, such as engine speed (rpm). The transmission control unit 31 defines a first gear shift map GM(1), a second shift map GM(2), and a third shift map GM(3). In this embodiment, the control system 1 is configured to control the transmission system 3(2) to select one of the first gear shift map GM(1), the second gear shift map GM(2), and the third gear shift map GM(3). The first gear shift map GM(1) represents the default or normal shift map of the transmission 31. The second shift map GM(2) represents the high-rpm shift map of the transmission 31. The high-rpm shift map defines a higher engine speed (rpm) for shifting gears. The second shift map GM(2) may delay the selection of high-rpm gears compared to the first (default) shift map GM(1). This usually results in higher engine speeds (rpm), and for example, as the engine speed increases, one or more lower gears (e.g., 1st to 4th gear) will be maintained. This allows the engine to continue operating at or near its peak power output.The second shift map GM(2) may be selected when driving on terrain including high-resistance surfaces such as snow or soft sand. The third gear shift map GM(3) represents a low-speed gear shift map for transmission 31. The low-speed gear shift map defines the low engine speeds (rpm) at which gear changes are performed. The third gear shift map GM(3) may select higher gears earlier compared to the first (default) gear shift map GM(1). The third gear shift map GM(3) may prioritize the selection (or holding) of higher gears compared to the first (default) shift map GM(1). This usually results in a decrease in engine speed (rpm), and as engine speed increases, for example, downshifts in lower gears (such as 1st to 4th gear) occur earlier. This may delay or avoid the occurrence of maximum power in certain engine speed ranges. A third gear shift map GM(3) may be selected when driving on terrain including low-friction surfaces such as grass. The first, second, and third gear shift maps GM(1)-GB(3) are predefined. It will be understood that fewer than three or more gear shift maps may be defined for selection by the control system 1. The transmission system 3(2) may optionally include a transfer case 35 that is operable to selectively engage the high drive ratio and the low drive ratio. At least one transmission control unit 31 is configured to control the operation of the transfer case 35. The control system 1 may optionally control the transmission system 3(2) and control the selection of the high drive ratio and the low drive ratio.

[0088] The control system 1 outputs a control signal 155 requesting the selection of one of the first, second, and third gear shift maps GM(1)-GM(3) based on one or more terrain indicator parameters 165(n). The control signal 155 controls the transmission system 3(1) to select one of the first, second, and third gear shift maps GM(1)-GM(3). Based on the determination that GGS control mode 170(2) is selected, the control system 1 is configured to change the second configurable control parameter CCP(2) as follows.

[0089] Based on the determination that the terrain type is grassland, the second gear shift map GM(2) is selected.

[0090] Based on the determination that the terrain type is gravel, the first gear shift map GM(1) is selected.

[0091] Based on the determination that the terrain type is shallow snow terrain, the second gear shift map GM(2) is selected.

[0092] Based on the determination that the terrain type is deep snow terrain, the third gear shift map GM(3) is selected.

[0093] Based on the determination that the terrain type is hard sand, the first gear shift map GM(1) is selected.

[0094] Based on the determination that the terrain type is soft sand, the third gear shift map GM(3) is selected.

[0095] The process of selecting either the first or second gear shift map GM(1) or GM(2) is performed independently of the selected subsystem control mode 170(n). Therefore, either the first or second gear shift map GM(1) or GM(2) can be selected without changing the subsystem control mode 170(n).

[0096] As schematically shown in Figure 4C, the front wheel steering system 3(3) comprises a front wheel steering control unit 41 and a steering wheel 43 for steering the front wheels 9(1)-9(2). The front wheel steering system 3(3) also comprises a steering assist actuator 45 for assisting the steering of the vehicle 5. A steering angle sensor 47 is provided to measure the steering angle of the steering wheel 43. In this embodiment, the steering assist actuator 45 is an electric actuator. In a modified example, the steering assist actuator 45 is a hydraulic actuator. The front wheel steering control unit 41 comprises one or more electronic processors. The front wheel steering control unit 41 is configured to control the operation of the steering assist actuator 43. The front wheel steering control unit 41 defines a third configurable control parameter CCP(3) for controlling the operation of the steering assist actuator 45. As described herein, the control system 1 is configured to change one or more third configurable control parameters CCP(3) in response to one or more terrain indicator parameters 165(n). The third configurable control parameter CCP(3) consists of front wheel steering maps FWSM(n) for the steering assist actuator 45. Multiple front wheel steering maps FWSM(n) are defined. The third configurable control parameter CCP(3) is changed by changing the selected front wheel steering map FWSM(n). The front wheel steering map FWSM(n) defines the relationship between the steering input and the magnitude of the assist generated by the steering assist actuator 43. The steering input is a variable measured by the steering angle sensor 47. The steering input consists of the steering angle and / or the rate of change of the steering angle. In this embodiment, the steering control unit 41 defines a first front wheel steering map FWSM(1), a second front wheel steering map FWSM(2), and a third front wheel steering map FWSM(3).The control system 1 is configured to control the front wheel steering system 3(3) to select one of the following: a first front wheel steering map FWSM(1), a second front wheel steering map FWSM(2), and a third front wheel steering map FWSM(3). The first front wheel steering map FWSM(1) represents the default or normal front wheel steering map for the steering assist actuator 45. The second front wheel steering map FWSM(2) represents a stiff front wheel steering map (i.e., reduced assist) for the steering assist actuator 45. The third front wheel steering map FWSM(3) represents a light front wheel steering map (i.e., increased assist) for the steering assist actuator 45. The front wheel steering maps FWSM(1)-FWSM(3) are predefined. It will be understood that it is possible to define fewer than three or more front wheel steering maps FWSM(n) and select them by the control system 1.

[0097] The second front wheel steering map FWSM(2) provides a heavier steering input and is suitable for surfaces with a low coefficient of friction. This is because it tends to delay the steering input, thereby reducing the risk of the vehicle 5 entering unstable dynamic states such as oversteer. The third front wheel steering map FWSM(3) provides a lighter steering input and is suitable for surfaces with high resistance, such as deep snow or soft sand, reducing the burden on the driver. The control system 1 outputs a control signal 155 requesting the selection of one of the first, second, and third front wheel steering maps FWSM(1)-FWSM(3) based on one or more terrain index parameters 165(n). The control signal 155 controls the front wheel steering system 3(3) to select one of the first and second front wheel steering maps FWSM(1) or FWSM(2). Based on the determination that GGS control mode 170(2) is selected, the control system 1 is configured to change the third configurable control parameter CCP(3) as follows.

[0098] Based on the determination that the terrain type is grassland, the second front wheel steering map FWSM(2) is selected.

[0099] Based on the determination that the terrain type is gravel, the first front wheel steering map FWSM(1) is selected.

[0100] In response to the determination that the terrain type is gravel, the second front wheel steering map FWSM(2) is selected.

[0101] In response to the determination that the terrain type is shallow snow, the third front wheel steering map FWSM(3) is selected.

[0102] Based on the determination that the terrain type is hard sand, the first front wheel steering map FWSM(1) is selected.

[0103] Based on the determination that the terrain type is soft sand, the third front wheel steering map FWSM(3) is selected.

[0104] The process of selecting one of the first, second, or third front wheel steering maps FWSM(1)-FWSM(3) is performed independently of the selected subsystem control mode 170(n). Therefore, the selected front wheel steering map FWSM(n) can be changed based on one or more terrain indicator parameters 165(n) without changing the subsystem control mode 170(n).

[0105] As schematically shown in Figure 4D, the brake system 3(4) comprises a brake control unit 51 and a plurality of friction brakes 53(1)-53(4) for applying braking (deceleration) force to each wheel 9(1)-9(4) of the vehicle 5. Alternatively, braking can also be performed by one or more electric motors provided on the vehicle 5. The friction brakes 53(1)-53(4) are operated in response to the operation of the brake pedal 55. A brake pedal sensor 57 is provided to detect the position of the brake pedal 55. The brake control unit 51 comprises one or more electronic processors. The brake control unit 51 defines a fourth configurable control parameter CCP(4) for controlling the operation of the friction brakes 53(1)-53(4). As described herein, the control system 1 is configured to change one or more of the fourth configurable control parameters CCP(4) in response to one or more terrain index parameters 165(n). A fourth configurable control parameter CCP(4) includes brake maps BM(n) for friction brakes 53(1)-53(4). Multiple brake maps BM(n) are defined. The fourth configurable control parameter CCP(4) is changed by changing the selected brake map BM(n). Each brake map BM(n) defines a relationship between the braking force applied by the friction brakes 53(1)-53(4) in response to the brake input. For example, the brake system 3(4) can change the relationship between the braking force generated by the friction brakes 53(1)-53(4) and the stroke of the brake pedal 55. In this embodiment, at least a first brake map BM(1) and a second brake map BM(2) are defined. The first brake map BM(1) represents a default or normal brake map. The second brake map BM(2) represents a map with a longer stroke of the brake pedal 55. The first brake map BM(1) and the second brake map BM(2) are predefined. It will be understood that two or more brake maps BM(n) may be defined for selection by control system 1.

[0106] The control system 1 outputs a control signal 155 that requests the selection of one of the first and second brake maps BM(1) and BM(2) based on one or more terrain indicator parameters 165(n). The control signal 155 controls the brake system 3(4) to select one of the first and second brake maps BM(1) and BM(2). Based on the determination that GGS control mode 170(2) is selected, the control system 1 is configured to change the fourth configurable control parameter CCP(4) as follows.

[0107] Based on the determination that the terrain type is grassland, the second brake map BM (2) is selected.

[0108] In response to the determination that the terrain type is grassland, the first brake map BM(1) is selected.

[0109] In response to the determination that the terrain type is shallow snow, the second brake map BM(2) is selected.

[0110] In response to the determination that the terrain type is deep snow, the second brake map BM(2) is selected.

[0111] Based on the determination that the ground type is hard sand, the first brake map BM(1) is selected.

[0112] Based on the determination that the ground type is soft sand, the second brake map BM(2) is selected.

[0113] The process of selecting either the first or second brake map BM(1) or BM(2) is performed independently of the selected subsystem control mode 170(n). Therefore, the brake maps BM(1) and BM(2) can be changed based on one or more terrain indicator parameters 165(n) without changing the subsystem control mode 170(n).

[0114] As schematically shown in Figure 4E, the suspension system 3(5) consists of a suspension control unit 61 and a plurality of suspension units 63(1)-63(4). The control system 1 is configured to control the suspension system 3(5) based on one or more terrain index parameters 165(n). The suspension units 63(1)-63(4) are associated with each wheel 9(1)-9(4) of the vehicle 5. In this embodiment, the suspension system 3(5) is a height-adjustable suspension. The height of each suspension unit 63(1)-63(4) is adjustable. The suspension system 3(5) may be, for example, an air suspension or a mechanically variable suspension. The height of the suspension system 3(5) is controlled to raise and lower the vehicle body by, for example, controlling the inflation and deflation of one or more air bladders provided in the suspension units 63(1)-63(4). In a further modification, the suspension 3(5) comprises one or more actuators configured to control the movement of the vehicle body. The control system 1 is configured to control the suspension system 3(5) to adjust, for example, the height of one or more of the suspension units 63(1)-63(4).

[0115] The suspension control unit 61 defines a fifth configurable control parameter CCP(5) for controlling the operation of the suspension units 63(1)-63(4). As described herein, the control system 1 is configured to change one or more fifth configurable control parameters CCP(5) in accordance with one or more terrain indicator parameters 165(n). The fifth configurable control parameter CCP(5) includes a suspension height setting SC(n) for each suspension unit 63(1)-63(4). Multiple suspension height settings SC(n) are defined. The fifth configurable control parameter CCP(5) is changed by changing the selected suspension height setting SC(n). In this embodiment, the suspension control unit 61 defines a first suspension height setting SC(1), a second suspension height setting SC(2), and a third suspension height setting SC(3). The first suspension height setting SC(1) represents a control mode in which the height of the units 63(1)-63(4) is automatically adjusted. The second suspension height setting SC(2) represents a first off-road setting in which suspension units 63(1)-63(4) are set to a first (intermediate) suspension height. The third suspension height setting SC(3) is a second off-road setting in which suspension units 63(1)-63(4) are set to a second (high) suspension height, and the second suspension height is higher than the first suspension height. Suspension height settings SC(n) are predefined. It will be understood that there may be fewer than three or more suspension height settings SC(n) for selection by the control system 1.

[0116] The control system 1 outputs a control signal 155 requesting the selection of one of the first, second, and third suspension height settings SC(1)-SC(3) based on one or more terrain indicator parameters 165(n). The control signal 155 controls the suspension system 3(5) to select one of the first, second, and third suspension height settings SC(1)-SC(3). Based on the determination that GGS control mode 170(2) is selected, the control system 1 is configured to change the fifth configurable control parameter CCP(5) as follows.

[0117] Based on the determination that the terrain type is grassland, the first suspension height setting SC(1) is selected.

[0118] In response to the determination that the terrain type is gravel, the first suspension height setting SC(1) is selected.

[0119] In response to the determination that the terrain type is shallow snow, the first suspension height setting SC(1) is selected.

[0120] In response to the determination that the terrain type is deep snow, the third suspension height setting SC(3) is selected.

[0121] Based on the determination that the terrain type is hard sand, the first suspension height setting SC(1) is selected.

[0122] Based on the determination that the terrain type is soft sand, the first suspension height setting SC(1) is selected.

[0123] The process of selecting one of the suspension height settings SC(n) is performed independently of the selected subsystem control mode 170(n). Therefore, the suspension height setting SC(n) can be changed based on one or more terrain indicator parameters 165(n) without changing the subsystem control mode 170(n).

[0124] As schematically shown in Figure 4F, the differential system 3(6) comprises a differential control unit 71 and one or more lockable differentials 73(n). The control system 1 is configured to control the differential system 3(6) based on one or more terrain indicator parameters 165(n). The differential system 3(6) may consist of, for example, one or more central differentials, rear differentials, and front differentials. In this embodiment, the differential system 3(6) consists of a central differential 73(1), a rear differential 73(2), and a front differential 73(3). The differential control unit 71 consists of one or more electronic processors.

[0125] The differential control unit 71 defines one or more sixth configurable control parameters CCP(6) for controlling the operation of the differentials 73(n). As described herein, the control system 1 is configured to change one or more sixth configurable control parameters CCP(6) in accordance with one or more terrain indicator parameters 165(n). The sixth configurable control parameter CCP(6) includes a differential configuration DC(n) for each of the lockable differentials 73(n). Multiple differential configuration DC(n) are defined. The sixth configurable control parameter CCP(6) is changed by changing the selected differential configuration DC(n). The differential configuration DC(n) defines an operating state (lock / unlock) for each of the central differential 73(1), rear differential 73(2), and front differential 73(3). The differential control unit 71 defines a first differential configuration DC(1), a second differential configuration DC(2), and a third differential configuration DC(3). The control system 1 controls the differential system 3(6) and is configured to select one of these differential configurations DC(n). The first differential configuration DC(1) defines a state in which the locking and unlocking of the central differential 73(1), rear differential 73(2), and front differential 73(3) are performed automatically. The second differential configuration DC(2) defines a configuration in which the central differential 73(1) is locked. The third differential configuration DC(3) defines a configuration in which both the central differential 73(1) and the rear differential 73(2) are locked. It will be understood that there may be fewer than three or more differential configurations DC(n) that can be selected by the control system 1. It will also be understood that the lock torque and vehicle-speed unlock torque of each differential will vary depending on the vehicle 5.

[0126] The control system 1 outputs a control signal 155 that requests the selection of one of the first, second, and third differential configurations DC(1)-DC(3) based on one or more terrain indicator parameters 165(n). The control signal 155 controls the differential system 3(6) to select one of the first, second, and third differential configurations DC(1)-DC(3). Based on the determination that GGS control mode 170(2) is selected, the control system 1 is configured to change the first configurable control parameter CCP(1) as follows.

[0127] In response to the determination that the terrain type is grassland, the second differential configuration DC(2) is selected.

[0128] In response to the determination that the terrain type is gravel, the second differential configuration DC(2) is selected.

[0129] In response to the determination that the terrain type is shallow snow, the first differential configuration DC(1) is selected.

[0130] In response to the determination that the terrain type is deep snow, the third differential configuration DC(3) is selected.

[0131] Based on the determination that the terrain type is hard sand, the first differential configuration DC(1) is selected.

[0132] Based on the determination that the terrain type is soft sand, the second differential configuration DC(2) is selected.

[0133] The process of selecting either differential configuration DC(1) or DC(2) is performed independently of the selected subsystem control mode 170(n). Therefore, the differential configuration DC(n) can be changed based on one or more terrain indicator parameters 165(n) without changing the subsystem control mode 170(n).

[0134] As schematically shown in Figure 4G, the traction control system 3(7) may be configured to control one or more vehicle subsystems 3(n) to maintain traction. The control system 1 is configured to control the traction control system 3(7) based on one or more terrain indicator parameters 165(n). The traction control system 3(7) includes a traction control unit 81. The traction control system 3(7) is configured to monitor the wheel speed of each wheel 9(1)-9(4) and to detect wheel slip events in one or more of the wheels 9(1)-9(4). The traction control system 3(7) may be configured, for example, to control the brake system 3(4) in response to the detection of a wheel slip event, and to control the application of braking (deceleration) force to one or more of the wheels 9(1)-9(4). A wheel slip event is detected by comparing a measured variation in wheel speed with a wheel speed threshold. A wheel slip event is detected if the variation in wheel speed is determined to be greater than the wheel speed threshold. The wheel slip threshold can be increased to reduce the sensitivity of wheel slip detection. Alternatively, the wheel slip threshold can be decreased to increase the sensitivity of wheel slip detection. The traction control unit 81 defines one or more seventh configurable control parameters CCP(7) for controlling the operation of the brake system 3(4). As described herein, the control system 1 is configured to modify one or more seventh configurable control parameters CCP(7) based on one or more terrain indicator parameters 165(n). The seventh configurable control parameter CCP(7) includes a wheel slip threshold STH(n) for detecting wheel slip events. Multiple wheel slip thresholds STH(n) are defined. The seventh configurable control parameter CCP(7) is modified by changing the selected wheel slip threshold STH(n).

[0135] The traction control unit 81 defines a first wheel slip threshold STH(1) and a second wheel slip threshold STH(2). The control system 1 is configured to control the traction control system 3(7) to select either the first wheel slip threshold STH(1) or the second wheel slip threshold STH(2). The first, second, and third wheel slip thresholds STH(1), STH(2), and STH(3) are different from each other. The first wheel slip threshold STH(1) is the default amount of wheel slip. The second wheel slip threshold STH(2) is smaller than the first wheel slip threshold STH(1) and allows for a smaller amount of wheel slip. The third wheel slip threshold STH(3) is larger than the first wheel slip threshold STH(1) and allows for a larger amount of wheel slip. The wheel slip thresholds STH(1)-STH(3) are predefined. It will be understood that three or more wheel slip thresholds may be defined for selection by control system 1.

[0136] The first wheel slip threshold STH(1) is the default setting and is suitable for use on high friction surfaces such as asphalt. The second wheel slip threshold STH(2) is defined to reduce wheel spin and is suitable for use on low friction surfaces or uneven surfaces, such as mud or ruts. The third wheel slip threshold STH(3) is defined to increase wheel spin and is suitable for use on high-resistance surfaces such as deep snow or soft sand. The third wheel slip threshold STH(3) may also be suitable for deformed surfaces such as off-road surfaces, gravel, and ruts to avoid sudden traction intervention. The control system 1 outputs a control signal 155 requesting the selection of either the first or second wheel slip threshold STH(1) or STH(2) based on one or more terrain index parameters 165(n). The control signal 155 controls the traction control system 3(7) to select one of the first, second, and third wheel slip thresholds STH(1)-STH(3). Based on the determination that GGS control mode 170(2) is selected, the control system 1 is configured to change the first configurable control parameter CCP(1) as follows.

[0137] Based on the determination that the terrain type is grassland, a second wheel slip threshold STH(2) is selected.

[0138] In response to the determination that the terrain type is gravel, a third wheel slip threshold STH(3) is selected.

[0139] In response to the determination that the terrain type is shallow snow, a second wheel slip threshold STH(2) is selected.

[0140] Based on the determination that the terrain type is deep snow terrain, a third wheel slip threshold STH(3) is selected.

[0141] Based on the determination that the terrain type is hard sand, a third wheel slip threshold STH(3) is selected.

[0142] Based on the determination that the terrain type is soft sand, a third wheel slip threshold STH(3) is selected.

[0143] The process of selecting either the first or second wheel slip threshold STH(1) or STH(2) is performed independently of the selected subsystem control mode 170(n). Therefore, the wheel slip thresholds STH(1) and STH(2) can be changed based on one or more terrain indicator parameters 165(n) without changing the subsystem control mode 170(n).

[0144] As schematically shown in Figure 4H, the ride comfort control system 3(8) consists of a ride comfort control unit 91 and a plurality of dampers 93(1)-93(4). The dampers 93(1)-93(4) are provided to control the damping of each suspension unit 63(1)-63(4). The control system 1 is configured to control the ride system 3(5) based on one or more terrain index parameters 165(n). The dampers 93(1)-93(4) are associated with each suspension unit 63(1)-63(4). The dampers 93(1)-93(4) are adjustable. The control system 1 is configured to control the ride system 3(8) to adjust the damping stiffness of the dampers 93(1)-93(4).

[0145] The suspension control unit 61 defines an eighth configurable control parameter CCP(8) for controlling the operation of dampers 93(1)-93(4). As described herein, the control system 1 is configured to change one or more eighth configurable control parameters CCP(8) based on one or more terrain indicator parameters 165(n). The eighth configurable control parameter CCP(8) consists of damper settings DS(n) for each of the dampers 93(1)-93(4). Multiple damper settings DS(n) are defined. The eighth configurable control parameter CCP(8) is changed by changing the selected damper setting DS(n). In this embodiment, the damper control unit 91 defines a first damper setting DS(1), a second damper setting DS(2), and a third damper setting DS(3). The first damper setting DS(1) represents the default setting for dampers 93(1)-93(4). The second damper setting DS(2) represents a soft setting for dampers 93(1)-93(4). The third damper setting DS(3) represents a stiff setting for dampers 93(1)-93(4). Damper settings DS(n) are predefined. It will be understood that fewer than three or more damper settings DS(n) may be defined for selection by control system 1.

[0146] The control system 1 requests the selection of one of the first, second, and third damper settings DS(1), DS(2), and DS(3) depending on one or more of the terrain indicator parameters 165(n). The control signal 155 controls the ride system 3(8) to select one of the first, second, and third damper settings DS(n). Based on the determination that GGS control mode 170(2) is selected, the control system 1 is configured to change the eighth configurable control parameter CCP(8) as follows.

[0147] Based on the determination that the terrain type is grassland, the second damper setting DS(2) is selected.

[0148] Based on the determination that the terrain type is gravel, the first damper setting DS(1) is selected.

[0149] Based on the determination that the terrain type is shallow snow terrain, the first damper setting DS(1) is selected.

[0150] Based on the determination that the terrain type is deep snow terrain, the third damper setting DS(3) is selected.

[0151] Based on the determination that the terrain type is hard sand, the first damper setting DS(1) is selected.

[0152] Based on the determination that the terrain type is soft sand, the third damper setting DS(3) is selected.

[0153] The process of selecting one of the damper settings DS(n) is performed independently of the selected subsystem control mode 170(n). Therefore, the damper setting DS(n) can be changed based on one or more terrain indicator parameters 165(n) without changing the subsystem control mode 170(n).

[0154] As schematically shown in Figure 4I, the rear-wheel steering system 3(3) comprises a rear-wheel steering control unit 101 for steering the rear wheels 9(3)-9(4). The rear-wheel steering system 3(3) also includes a rear-wheel steering actuator 105 for assisting the steering of the vehicle 5. The rear-wheel steering control unit 101 comprises one or more electronic processors. The rear-wheel steering control unit 101 is configured to control the operation of the rear-wheel steering actuator 105. The rear-wheel steering control unit 101 defines a ninth configurable control parameter CCP(9) for controlling the operation of the rear-wheel steering actuator 105. As described herein, the control system 1 is configured to change one or more ninth configurable control parameters CCP(9) based on one or more terrain indicator parameters 165(n). The ninth configurable control parameter CCP(9) consists of rear-wheel steering maps RWSM(n) for the rear-wheel steering actuator 105. Multiple rear-wheel steering maps RWSM(n) are defined. The ninth configurable control parameter CCP(9) is changed by changing the selected rear wheel steering map RWSM(n). Each rear wheel steering map RWSM(n) defines the relationship between a steering input (or steering request) and the magnitude of the rear wheel steering angle generated by the rear wheel steering actuator 105. In this embodiment, the rear wheel steering control unit 101 defines a first rear wheel steering map RWSM(1) and a second rear wheel steering map RWSM(2). The control system 1 is configured to control the rear wheel steering system 3(3) to select either the first rear wheel steering map RWSM(1) or the second rear wheel steering map RWSM(2). The first rear wheel steering map RWSM(1) represents the default or normal rear wheel steering map for the steering assist actuator 45. The first rear wheel steering map RWSM(1) controls the rear wheel steering actuator 105 to generate a rear wheel steering angle that is out of phase with the front wheel steering angle.In other words, the rear wheels 9(3) and 9(4) steer in the opposite direction to the front wheels 9(1) and 9(2). The second rear wheel steering map RWSM(2) controls the rear wheel steering actuator 105 to generate a rear wheel steering angle that is in phase with the front wheel steering angle. In other words, the rear wheels 9(3) and 9(4) steer in the same direction as the front wheels 9(1) and 9(2). The rear wheel steering maps RWSM(1)-RWSM(3) are predefined. It will be understood that two or more rear wheel steering maps RWSM(n) can be defined for selection by the control system 1.

[0155] The first rear-wheel steering map RWSM(1) provides rear-wheel steering that is out of phase with the front-wheel steering. This is the default setting and is suitable for driving on public roads. The second rear-wheel steering map RWSM(2) provides rear-wheel steering that is in phase with the front-wheel steering. In-phase steering input generates lateral (crab-like) movement. This is suitable for fine-tuning the steering angle to reduce the risk of the vehicle entering dynamic states such as oversteer (e.g., oversteer). Its characteristics may vary depending on the steering angle and vehicle speed. The control system 1 outputs a control signal 155 requesting the selection of one of the first, second, and third rear-wheel steering maps RWSM(1)-RWSM(3) based on one or more terrain index parameters 165(n). The control signal 155 controls the rear-wheel steering system 3(9) to select one of the first and second rear-wheel steering maps RWSM(1) and RWSM(2). Based on the determination of whether GGS control mode 170(2) is selected, the control system 1 is configured to change the ninth configurable control parameter CCP(9) as follows.

[0156] Based on the determination that the terrain type is grassland, the second rear-wheel steering map RWSM(2) is selected.

[0157] Based on the determination that the terrain type is gravel, the first rear-wheel steering map RWSM(1) is selected.

[0158] In response to the determination that the terrain type is shallow snow, the first rear-wheel steering map RWSM(1) is selected.

[0159] In response to the determination that the terrain type is deep snow, the second rear-wheel steering map RWSM(2) is selected.

[0160] Based on the determination that the terrain type is hard sand, the first rear-wheel steering map RWSM(1) is selected.

[0161] Based on the determination that the terrain type is soft sand, the second rear-wheel steering map RWSM(2) is selected.

[0162] The process of selecting one of the first, second, or third rear-wheel steering maps RWSM(1)-RWSM(3) is performed independently of the selected subsystem control mode 170(n). Therefore, the selected rear-wheel steering map RWSM(n) can be changed based on one or more terrain indicator parameters 165(n) without changing the subsystem control mode 170(n).

[0163] The control system 1 is configured to change the configurable control parameter CCP(n) based on a determination of whether or not the terrain type is deep snow terrain. The control system 1 can determine that the terrain type is shallow snow terrain based on a determination that the ambient temperature AMT is lower than the temperature threshold TTH and the rolling resistance Frr is lower than the rolling resistance threshold RRT. Alternatively, in addition to the above, the control system 1 may determine that the terrain type is shallow snow terrain based on a determination that the ambient temperature AMT is higher than the temperature threshold TTH and the estimated road surface friction coefficient (μ) is lower than the first road surface friction threshold SFT1. The first road surface friction threshold SFT1 may be predefined. For example, the first road surface friction threshold SFT1 may correspond to a friction coefficient of 0.4. Based on the determination that the terrain type is shallow snow terrain, the control system 1 can change one or more configurable control parameters CCP(n).

[0164] Alternatively, in addition to the above, the control system 1 determines that the terrain type is gravel based on the judgment that the ambient temperature AMT is greater than the temperature threshold TTH, the estimated surface friction (μ) is greater than the first surface friction threshold SFT1, and less than the second surface friction threshold SFT2. The second surface friction threshold SFT2 may be predefined. For example, the second surface friction threshold SFT2 may correspond to a friction coefficient of 0.8. Based on the determination that the terrain type is gravel, the control system 1 may change one or more configurable control parameters CCP(n).

[0165] Alternatively, or in addition, control system 1 may determine that the terrain type is grassland based on the determination that the following conditions are met: (i) the ambient temperature AMT is greater than the temperature threshold TTH; and (ii) the estimated surface friction coefficient (μ) is less than the first surface friction threshold SFT1. Based on the determination that the terrain type is grassland, control system 1 may change one or more configurable control parameters CCP(n).

[0166] Alternatively, in addition to the above, the control system 1 may determine that the terrain type is gravel based on the determination that the following conditions are met: (i) the ambient temperature AMT is greater than the temperature threshold TTH; (ii) the estimated surface friction coefficient (μ) is greater than the first surface friction threshold SFT1 and less than the second surface friction threshold SFT2; and (iii) the surface roughness SRT is within a predetermined surface roughness range. The surface roughness range is defined by the first (lower) surface roughness threshold SRT1 and / or the second (upper) surface roughness threshold SRT2. In this embodiment, the lower surface roughness threshold SRT1 is defined as 10%, and the upper surface roughness threshold SRT2 is defined as 35%. Other values ​​may also be used to define the surface roughness thresholds SRT1 and SRT2. The control system 1 may change one or more configurable control parameters CCP(n) depending on the determination that the terrain type is gravel. The control system 1 may be configured to suppress the determination that the terrain type is grassland, snow, or deep snow when it is determined that the surface roughness exceeds a first surface roughness threshold SRT1.

[0167] A method 400 for controlling the operation of at least one vehicle subsystem 3(n) will be described with reference to the block diagram 410 shown in Figure 5. GGS control mode 170(2) is selected (block 420). The selection of GGS control mode 170(2) is based on one or more terrain index parameters and one or more atmospheric index parameters 185(n). One or more atmospheric index parameters 185(n) include ambient temperature AMT. Ambient temperature AMT is compared to a temperature threshold TTH. A determination is made as to whether ambient temperature AMT is less than the temperature threshold TTH (block 430). In this embodiment, the temperature threshold TTH is defined as -5°C. If ambient temperature AMT is less than the temperature threshold TTH, the rolling resistance Frr is compared to the rolling resistance threshold RRT. In this embodiment, the rolling resistance threshold RRT is defined as 2000N. Other values ​​may be assigned to the rolling resistance threshold RRT. The rolling resistance threshold RRT may be greater than or less than 2000N. It is determined whether the rolling resistance Frr is less than the rolling resistance threshold RRT (block 440). Based on the determination that the rolling resistance Frr is greater than the rolling resistance threshold RRT, it is determined that the vehicle 5 is traveling on deep snow terrain (block 450). One or more first configurable control parameters CCP(1) are defined based on the determination that the vehicle 5 is traveling on deep snow terrain. Method 400 includes changing one or more configurable control parameters CCP(n) based on the determination that the terrain type is deep snow terrain (block 460).

[0168] As described above, the rolling resistance Frr is compared with the rolling resistance threshold RRT (block 440). Based on the determination that the rolling resistance Frr is less than the rolling resistance threshold RRT, it is determined that vehicle 5 is traveling on shallow snow terrain (block 470). Method 400 includes changing one or more configurable control parameters CCP(n) based on the determination that the terrain type is shallow snow terrain (block 480).

[0169] If the ambient temperature AMT is greater than the temperature threshold TTH (block 430), the estimated road surface friction coefficient (μ) is compared with the first road surface friction threshold SFT1. A check is performed to determine whether the estimated road surface friction coefficient (μ) is smaller than the first road surface friction threshold SFT1, that is, whether μ<SFT1 (block 490). The first surface friction threshold SFT1 is defined as 0.4 in the present embodiment. The first surface friction threshold SFT1 may be smaller or larger than 0.4. Based on the determination that the estimated surface friction (μ) is less than the first road surface friction threshold SFT1, it is determined that the vehicle is traveling on wet grassland (block 500). The method 400 includes modifying one or more configurable control parameters CCP(n) based on the determination that the terrain type is wet grassland terrain (block 510). If the ambient temperature AMT falls below the temperature threshold TTH (block 430), it may be determined that the terrain has changed from the wet grassland terrain (block 500) to the shallow snow terrain (block 470).

[0170] If the estimated surface friction coefficient (μ) is greater than the first surface friction threshold SFT1 (block 490), the estimated surface friction coefficient (μ) is compared with the second surface friction threshold SFT2. A determination is made as to whether the estimated surface friction coefficient (μ) is smaller than the second surface friction threshold SFT2, that is, whether SFT1<μ<SFT2 (block 560). Based on the determination that the estimated road surface friction coefficient (μ) is smaller than the second road surface friction threshold SFT2 (that is, SFT1<μ<SFT2), it is determined that the vehicle 5 is traveling on a gravel surface (block 570). In the present embodiment, the second road surface friction threshold SFT2 is defined as 0.8. The second road surface friction threshold SFT2 may be smaller or larger than 0.8. The method 400 includes modifying one or more configurable control parameters CCP(n) based on the determination that the terrain type is gravel surface (block 580).

[0171] If the estimated surface friction coefficient (μ) is greater than the second surface friction threshold SFT2 (block 560), the surface roughness SFR (%) is compared with the surface roughness SFR threshold. It is determined whether the surface roughness SFR (%) is within the surface roughness range (block 590). Based on the determination that the road surface roughness (%) is within the surface roughness range, it is determined that the vehicle is traveling on gravel (block 570). Based on the determination that vehicle 5 is traveling on gravel, one or more first configurable control parameters CCP(1) are defined. Method 400 includes changing one or more configurable control parameters CCP(n) in response to the determination that the terrain type is gravel (block 580). It includes changing one or more configurable control parameters CCP(n) based on the determination that the type of ground surface is gravel (block 580).

[0172] If the surface roughness SFR(%) is outside the specified range (block 560), a different subsystem control mode 170(n) may be selected. For example, general driving control mode 170(1) may be selected. This process continues while vehicle 5 is in motion.

[0173] Table B below shows the configuration of the vehicle subsystem 3(n) in GGS control mode 170(2) depending on whether the terrain type is determined to be shallow snow or deep snow. Shallow snow is characterized by snow with a depth below a predetermined depth threshold, while deep snow has a depth exceeding a predetermined depth threshold. This table shows the configurable control parameter CCP(n) selected for each vehicle system 3(n). The configurable control parameter CCP(n) is defined based on one or more terrain index parameters 165(n). As described herein, one or more terrain index parameters 165(n) are used to distinguish between shallow snow terrain and deep snow terrain. The configurable control parameter CCP(n) is changed depending on whether the terrain type is determined to consist of shallow snow or deep snow. The configurable control parameter CCP(n) for each terrain type in GGS control mode 170(2) is summarized in Table B.

[0174] [Table B]

[0175] The control system 1 and method 400 according to the above embodiment have been described with particular reference to GSS control mode 170(2). It will be understood that the control system 1 and method 400 described herein can be used to reconfigure the vehicle subsystem 3(n) when any of the other control modes 170(n) are selected. For example, the control system 1 and method 400 can be used to reconfigure the vehicle subsystem 3(n) when sand control mode 170(4) is selected based on the hardness of the sandy terrain. A threshold for rolling resistance can be defined to distinguish between sandy terrain with a soft composition and sandy terrain with a hard composition. One or more of the configurable control parameters CCP(n) described herein may be changed according to the determination. The control system 1 and method 400 will now be described with respect to sand control mode 170(4).

[0176] Table C below shows the configuration of the vehicle subsystem 3(n) in sandy ground control mode 170(4), depending on whether the ground type is determined to consist of hard sand or soft sand. Hard sand is characterized as compacted sand or relatively shallow sand. In contrast, soft sand is characterized as relatively deep sand, for example, in dunes. This table shows the configurable control parameters CCP(n) selected for each of the vehicle systems 3(n). The configurable control parameters CCP(n) are defined based on one or more terrain index parameters 165(n). The configurable control parameters CCP(n) may optionally be defined based on one or more atmospheric index parameters 185(n). One or more terrain index parameters 165(n) are used to distinguish between hard sand and soft sand within sandy ground control mode 170(4). As described later, the configurable control parameter CCP(n) changes depending on whether the terrain type consists of hard sand or soft sand. The configurable control parameter CCP(n) for each of these terrain types within the sandy terrain control mode 170(4) is summarized in Table C.

[0177] [Table C]

[0178] Method 400 includes distinguishing between soft sand mode and hard sand mode when operating in sand control mode 170(4). Method 400 for controlling at least one vehicle subsystem 3(n) in sand control mode 170(4) is described below. Figure 6 shows a block diagram 600 representing the control process. Sand control mode 170(2) is selected (block 6100). The tire pressure monitoring sensor 13(11) outputs a tire pressure signal 15(11) indicating the measured tire pressure of each wheel 9(1)-9(4). When driving on sand, the tire pressure may be reduced (manually or automatically) to improve traction. This method includes comparing the measured tire pressure with a predefined tire pressure threshold TPT. If the measured tire pressure of each wheel 9(1)-9(4) is lower than a predefined tire pressure threshold TPT, the method 400 includes determining that the vehicle 5 is in an operating state suitable for driving on sand (block 620). The method also includes determining whether the vehicle 5 is pre-configured for driving on sand (block 630). For example, the vehicle 5 may be pre-configured for driving on sand by manually selecting a dedicated control mode. The sand control mode 170(4) is configured for driving on soft sand (block 640) based on the positive determination that the vehicle 5 is pre-configured for driving on sand (block 630). If the vehicle is not pre-configured for driving on sand, the rolling resistance Frr is compared with the rolling resistance threshold RRT (block 650). The rolling resistance threshold RRT is predefined. In this embodiment, the rolling resistance threshold RRT is defined as 2000N. The rolling resistance threshold RRT may be less than or greater than 2000N. If the rolling resistance Frr is less than the rolling resistance threshold RRT, the terrain type is determined to be hard sand (block 660). Method 400 includes changing one or more configurable control parameters CCP(n) based on the determination that the terrain type is hard sand. If the rolling resistance Frr is greater than the rolling resistance threshold RRT, the terrain type is determined to be soft sand (block 670).Method 400 includes modifying one or more configurable control parameters CCP(n) based on the determination that the terrain type is soft sand (block 480).

[0179] The control system 1 and method 400 according to the above embodiment apply one or more Boolean operators to any or all of the terrain indicator parameters 165(n) to select an auxiliary subsystem control mode 175(n). A configurable control parameter CCP(n) is defined based on the determined auxiliary subsystem control mode 175(n) to control the vehicle subsystem 3(n). In one embodiment, the auxiliary subsystem control mode 175(n) may be determined based on an auxiliary subsystem control mode probability 180(n). This modified example is shown in Figure 6. The auxiliary subsystem control mode probability 180(n) is an indicator of the suitability of each auxiliary subsystem control mode 175(n). The auxiliary subsystem control mode probability 180(n) may be determined using the same method described herein to select any of the vehicle subsystem control modes 170(n). The auxiliary subsystem control mode probability 180(n) is calculated for each auxiliary subsystem control mode 175(n). The auxiliary subsystem control mode probabilities 180(n) are compared with each other to determine which of the multiple auxiliary subsystem control modes 175(n) is suitable for the current driving conditions. The vehicle control unit 7 can integrate the mode selection probabilities 180(n) of each auxiliary subsystem control mode 175(n). This integration identifies a positive difference between the calculated mode selection probability 180(n) of the currently selected auxiliary subsystem control mode 175(n) and the calculated mode selection probability 180(n) of each of the other auxiliary subsystem control modes 170(n). The vehicle control unit 7 can change the selected subsystem control mode 170(n) if the integrated value exceeds a predetermined threshold, or if the current subsystem control mode selection probability 180(n) is zero or less than or equal to the subsystem control mode probability threshold. Since subsystem control mode 175(n) is a subset of vehicle subsystem control mode 170(n), the threshold for changing the selected auxiliary subsystem control mode 175(n) may be set lower than the threshold applied to select any of the subsystem control modes 170(n).

[0180] It will be understood that various changes and modifications can be made to the control system 1 and method 400 described herein without departing from the scope of the present invention.

Claims

1. A control system that controls at least one vehicle subsystem to control the dynamic operation of a vehicle, The control system is configured to select one of several subsystem control modes based on the determination of the type of terrain the vehicle is traveling on. Each of the plurality of subsystem control modes defines one or more configurable control parameters for controlling the operation of at least one vehicle subsystem, The control system includes one or more processors, The one or more processors described above are: Receiving at least one input signal including at least one terrain index parameter indicating the type of terrain on which the vehicle is traveling; Determining the type of terrain on which the vehicle is traveling based on the at least one terrain index parameter; and It is configured to select one of the plurality of subsystem control modes based on the determined type of terrain, The selected subsystem control modes define one or more configurable control parameters for at least one vehicle subsystem to operate in the determined terrain type, A control system in which one or more processors are collectively configured to set one or more configurable control parameters in a selected subsystem control mode from among a plurality of subsystem control modes, based on the at least one terrain index parameter.

2. In the control system according to claim 1, The at least one terrain index parameter includes at least one variable that represents the characteristics of the type of terrain on which the vehicle is traveling, A control system comprising one or more processors collectively configured to compare at least one variable with a predetermined threshold and to change one or more configurable control parameters in response to a determination of whether the at least one variable is greater than or less than the predetermined threshold.

3. In the control system according to claim 2, The at least one variable includes an estimate of rolling resistance, and the predetermined threshold is a predetermined rolling resistance threshold. A control system in which one or more configurable control parameters are changed based on a determination of whether the estimated value of the rolling resistance is greater than or less than a predetermined threshold of rolling resistance.

4. In the control system according to claim 2 or claim 3, The at least one variable includes an estimated road surface friction value, and the predetermined threshold is a predetermined surface friction threshold. A control system in which one or more configurable control parameters are changed according to whether the estimated surface friction value is greater than or less than a predetermined surface friction threshold.

5. In a control system according to any one of claims 2, 3, or 4, The at least one variable includes a surface roughness estimate, and the predetermined threshold is a predetermined surface roughness threshold. A control system in which one or more configurable control parameters are changed according to whether the estimated surface roughness value is greater than or less than a predetermined surface roughness threshold.

6. In the control system according to any one of claims 1 to 5, At least one of the plurality of subsystem control modes includes a plurality of auxiliary subsystem control modes, Each of the above-mentioned auxiliary subsystem control modes defines one or more modification control parameters for controlling the operation of at least one vehicle subsystem, A control system in which the setting of one or more configurable control parameters includes selecting a different of the multiple auxiliary subsystem control modes.

7. In the control system according to claim 6, The one or more processors described above are: The probability of a plurality of auxiliary subsystem control modes is determined based on the aforementioned at least one terrain index parameter, wherein the probability of the plurality of auxiliary subsystem control modes provides an index of the suitability of each of the plurality of auxiliary subsystem control modes. Selecting one auxiliary subsystem control mode from among the aforementioned plurality of auxiliary subsystem control modes, wherein the selection of the one auxiliary subsystem control mode is based on the determination that the probability of the one auxiliary subsystem control mode exceeds an auxiliary subsystem control mode probability threshold, A control system configured to perform the following actions.

8. In a control system according to any one of claims 1 to 7, The one or more processors described above are: The process involves determining the subsystem control mode probability for each of the aforementioned plurality of terrain indicator parameters based on at least one of the aforementioned terrain indicator parameters, wherein the plurality of subsystem control mode probabilities provide an indicator of the suitability of each of the plurality of auxiliary subsystem control modes. The process involves selecting one auxiliary subsystem control mode from among the aforementioned plurality of auxiliary subsystem control modes, wherein the selection of the auxiliary subsystem control mode is based on the determination that the subsystem control mode probability is greater than the subsystem control mode probability threshold. A control system configured to perform the following actions.

9. A control system according to claim 7 or 8, wherein the auxiliary subsystem control mode probability threshold is smaller than the subsystem control mode probability threshold.

10. In the control system according to any one of claims 1 to 9, The one or more configurable control parameters are: A first configurable control parameter, including one or more torque curves for controlling the operation of the propulsion system; A second configurable control parameter, including one or more gear shift maps for controlling the selection of the drive ratio of the transmission system; A third configurable control parameter, including one or more front wheel steering maps for controlling the front wheel steering system; A fourth configurable control parameter, including one or more brake maps for controlling the brake system; A fifth configurable control parameter, including one or more suspension height settings for controlling the suspension system; A sixth configurable control parameter, which includes one or more differential device configurations for controlling a differential system; A seventh configurable control parameter, which includes one or more wheel slip thresholds for controlling the traction control system; An eighth configurable control parameter, which includes one or more damper settings for controlling the ride comfort system; and A control system comprising one or more of the following 9th configurable control parameters, each containing one or more rear-wheel steering maps for controlling a rear-wheel steering system.

11. A vehicle comprising the control system according to any one of claims 1 to 10.

12. A method for controlling at least one vehicle subsystem in order to control the dynamic operation of a vehicle, Determining the type of terrain the vehicle is traveling on based on at least one terrain indicator parameter; This includes selecting one of a plurality of subsystem control modes based on the determined terrain type on which the vehicle is traveling, One of the selected subsystem control modes defines one or more control parameters for at least one vehicle subsystem for operation in the determined terrain type, Each of the plurality of subsystem control modes defines one or more configurable control parameters for controlling the operation of at least one vehicle subsystem, A method for setting one or more configurable control parameters in a selected subsystem control mode based on the at least one terrain index parameter.

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