Improvements to vehicle speed control

Abstract

Control system (10) for a vehicle (100), comprising: a torque control means for automatically applying a positive or negative torque to one or more wheels of a vehicle (100) as required, in order to cause a vehicle (100) to move in accordance with a target speed value; a path prediction means for predicting a path of the vehicle (100) in a direction of movement; a detection means for detecting one or more objects (195, 195A-C) in front of the vehicle (100); and a determination means for determining whether one or more objects (195, 195A-C) detected by the detection means are outside the predicted path;and control device, configured, at least in part, to automatically and temporarily reduce the vehicle speed automatically, depending on the distance of one or more detected objects (195, 195A-C) from the predicted path, when it is determined that one or more detected objects (195, 195A-C) are outside the predicted path; wherein reducing the vehicle speed comprises the control device limiting the vehicle speed to a speed limit, and wherein the predetermined speed limit is determined by multiplying a current speed value by an object proximity reduction factor less than one, wherein a value of the object proximity reduction factor is determined depending on the distance of one or more detected objects (195, 195A-C) from the predicted path and a height of one or more detected objects (195, 195A-C).

Description

INCLUSION BY REFERENCEThe contents of co-pending patent applications GB 2 507 622 A and GB 2 499 461 A are hereby incorporated by reference. The contents of U.S. Patent No. U.S. Pat. No. 7,349,776 B2 and the co-pending patent applications WO 2013 / 124 321 A1 and WO 2014 / 139 875 A1 are hereby incorporated by reference. The contents of British Patent Applications GB 2 492 748 A, GB 2 492 655 A and GB 2 499 279 A and British Patent GB 2 508 464 B are also incorporated herein by reference.FIELD OF THE INVENTIONThe invention relates to a system for controlling the speed of a vehicle. More particularly, but not limited to, the invention relates to a system for controlling the speed of a land vehicle that can travel on various and extreme terrain types.PRIOR ARTIn known vehicle cruise control systems, often referred to as cruise control systems, the vehicle speed once set by the user is maintained without further intervention by the user to improve the ride experience for the user by reducing workload. The cruise control speed (or set speed) is adjustable by the vehicle operator, typically by pressing a button when the vehicle is travelling at the desired speed. Plus and minus keys serve to step the speed change while the speed control is set.DE 10 2010 031 038 A1 relates to a method for assisting a driver of a motor vehicle in a driving maneuver, in which the environment of the vehicle is detected and it is checked whether at least one object is located in the environment of the vehicle and it is subsequently determined whether the vehicle approaches the object and a warning is output to the driver when the vehicle approaches the object up to a critical distance.DE 10 2007 036 417 A1 relates to a method for operating a distance control system for vehicles, in which the distance between a vehicle and a target object located in front of the vehicle is controlled as a function of the situation, taking into account predictive route data, by accelerating or decelerating system interventions.U.S. Pat. No. 7,349,776 B2 discloses a vehicle control system that has a plurality of subsystem control units, including an engine management system 28, a transmission control unit 30, a steering control unit 48, a brake control unit 62 and a suspension control unit 82.Once the user has selected a speed at which the vehicle is to be held, the vehicle is held at that speed as long as the user does not apply a brake or, in the case of a manual transmission vehicle, a clutch pedal. The speed control system takes its speed signal from a drive shaft speed sensor or wheel speed sensors. When the brake pedal or clutch pedal is actuated, the cruise control system is deactivated so that the user may override the cruise control system to change vehicle speed without resistance by the system. If the cruise control system is active, the vehicle speed will increase if the user sufficiently actuates the accelerator pedal, but if the user takes his foot off the accelerator pedal, then the vehicle will return to the preset speed by scrolling.These systems can normally only be operated above a certain speed, typically in the range of about 15-20 km / h, and are ideal under circumstances in which the vehicle is travelling in constant traffic conditions, and in particular on expressways and freeways. Under congestion conditions, but where vehicle speeds vary greatly, cruise control systems are ineffective and particularly when the systems are inoperative due to a minimum speed requirement. A minimum speed requirement is frequently imposed on cruise control systems to reduce the likelihood of low speed impact, for example, parking. These systems are thus ineffective under certain driving conditions (e.g., low speed) and are automatically deactivated under circumstances where a user may feel undesirable to do so.More sophisticated cruise control systems are incorporated into the engine management systems and may include adaptive functionality that takes into account the distance to the vehicle ahead using a radar system. For example, the vehicle may be equipped with a forward radar detection system so that the speed of the preceding vehicle is detected and a safe following speed and distance are automatically maintained without the request for user input. When the preceding vehicle is slowed or when another object is detected by the radar sensing system, the system sends a signal to the engine or brake system to correspondingly slow the vehicle to maintain a safe following distance.Known cruise control systems are further deactivated when a wheel slip event is detected that requires intervention by a traction control system (TCS) or a stability control system (SCS). Accordingly, they are not well suited to maintain vehicle motion during driving under off-road conditions in which these cases occur comparatively frequently.Some vehicles have been designed for off-highway use and low speed cruise control systems for these vehicles. Under off-highway conditions, low speed cruise control systems allow a driver, particularly an inexperienced driver, to focus on activities such as steering.Low speed cruise control systems suitable for terrain deployment may be configured to move at a speed that is below the user determined set speed depending on the unevenness of the terrain in which the vehicle is travelling. Nevertheless, the applicant of the present invention has recognized that there may be cases other than driving in rough driving circumstances in which a decreased vehicle speed would be useful for a user to master the terrainIt is also known to provide a control system to control one or more vehicle subsystems. US 7 349 776 B2 discloses a vehicle control system comprising several subsystems including an engine management system, a transmission control unit, a steering control unit, a brake control unit and a suspension control unit. The subsystem controllers are each operable in a plurality of subsystem function or configuration modes. The subsystem controllers are connected to a vehicle mode controller which controls the subsystem controllers to transition to a required function mode to provide multiple driving modes for the vehicle. Each of the driving modes corresponds to a particular driving condition or set of particular driving conditions, and in each mode, each of the subsystems is set to the most suitable function mode under those conditions. These conditions are related to various types of terrain over which the vehicle may be driven, such as grass / gravel / snow, slush and track grooves, creep on rocks, sand, and a highway mode called "special programs off" (SPO). The vehicle mode controller may be referred to as a terrain response (TR)(RTM) system or controller. The driving modes may also be referred to as terrain modes, terrain response modes, or control modes.GB 2 492 655 B discloses a control system for a motor vehicle in which the most suitable terrain mode for the terrain over which the vehicle is predominantly driven is automatically determined by the control system. The control system then causes the vehicle to operate in the off-road mode deemed most suitable.This invention has been made in consideration of this. Embodiments of the invention provide an apparatus, method or vehicle according to claims 1, 18 and 19, respectively, which addresses the above problems. Other objects and advantages of the present invention will become apparent from the description, the remaining claims and the drawings below.SUMMARY OF THE INVENTIONIn one aspect of the invention to be protected, a control system for a vehicle is provided, comprising:torque control means for automatically causing positive or negative torque to be applied to one or more wheels of a vehicle as required to cause a vehicle to move in accordance with a desired speed value;path prediction means for predicting a path of the vehicle in a moving direction;detecting means for detecting one or more objects in front of the vehicle;determining means for determining whether one or more objects detected by said detecting means are outside said predicted path; andA control means configured to automatically temporarily reduce vehicle speed based at least in part on a distance of the one or more detected objects from the predicted path when it is determined that the one or more detected objects are outside the predicted path.It should be appreciated that the path prediction means may predict a path of the vehicle based at least in part on a vehicle location and a steering angle. In some embodiments, the detecting means comprises a vehicle-mounted stereoscopic camera arrangement for obtaining 3D point cloud data, wherein the path predicting means predicts the path ahead of the vehicle based on the path having a curvature corresponding to the steering angle, the vehicle being at the origin of a reference frame of the 3D point cloud data. Alternatively, any other technology suitable for generating a 3D point cloud of the area in front of the vehicle may be employed, such as any 3D imaging technique, such as a scanning radar or lidar system.Optionally, automatically decreasing the vehicle speed includes the control means determining the vehicle speed in a case where one or more detected objects are within a predetermined distance of the predicted path.According to the invention, reducing the vehicle speed comprises the control means limiting the vehicle speed to a speed limit and wherein the speed limit is determined at least in part depending on the distance of the one or more detected objects from the predicted path and / or a height of the one or more detected objects.Optionally, the control system is configured wherein the speed limit is arranged to also decrease as the distance of the one or more detected objects from the predicted path decreases.The control system may be operable to determine a distance from which to begin the temporary reduction of the vehicle speed.Optionally, the speed limit may be a predetermined speed limit.Optionally, the control system is configured wherein automatically decreasing the vehicle speed comprises the control means decreasing the vehicle speed at least in part depending on the identity of a selected one of a plurality of driving modes in which the vehicle is operating.Optionally, the control system is configured, wherein in each driving mode at least one of a plurality of vehicle subsystems is caused to operate in a predetermined one of a plurality of configuration modes of that subsystem, the subsystem configuration mode being determined depending on the selected driving mode.Optionally, the control system is configured, wherein the subsystems include a powertrain subsystem, a brake subsystem, and / or a suspension subsystem.Optionally, the control system is configured wherein the torque control means comprises an electric controller configured to communicate with a powertrain controller and a brake controller.Optionally, the control system is configured to further temporarily automatically reduce the vehicle speed depending on a comfort indicator generated in response to a control input provided by a user.The control input may be generated using a switch, a rotary switch, a touch screen interface, or other suitable means. It should be appreciated that if the vehicle speed is already sufficiently low with respect to the comfort indicator and there is no further reason for decreasing the speed, the vehicle speed may not be decreased in response to the comfort indicator.Optionally, the control system comprises: an electronic processor configured to receive information from the sensing means indicating that one or more sensed objects are present in front of the vehicle; and an electronic storage device electrically coupled to the electronic processor and having instructions stored thereon, the processor configured to access the storage device and execute the instructions stored therein to be operable to:causing a positive or negative torque to be applied to one or more wheels of a vehicle to cause a vehicle to move in accordance with a desired speed value;predicting a path of the vehicle in a moving direction; anddetermining whether one or more objects detected by the detecting means are outside the predicted path and, depending at least in part on a distance of the one or more detected objects from the predicted path, automatically temporarily decreasing the vehicle speed when it is determined that the one or more detected objects are outside the predicted path.The sensing means may comprise a stereoscopic camera or lidar system.The control system may further include a proximity sensor.The control means may be configured to predict the decreased vehicle speed based on data from the proximity sensor.The control means may be configured to determine when the vehicle has passed the object and increase the vehicle speed.The path prediction means may be configured to predict a path of the vehicle in a direction of movement to receive image data, point cloud data and / or steering angle data.In a further aspect of the invention to be protected, there is provided a vehicle comprising a control system according to any preceding aspect.In another aspect of the invention to be protected, there is provided a method of controlling the speed of a vehicle implemented by a control system comprising:automatically causing a positive or negative torque to be applied to one or more wheels of a vehicle to cause a vehicle to move in accordance with a desired speed value; andpredicting a path of the vehicle in a moving direction; anddetermining whether one or more detectable objects are present in front of the vehicle;wherein the method further comprises determining whether one or more detectable objects are present in front of the vehicle outside the predicted path, wherein if it is determined that one or more detectable objects are present in front of the vehicle and are outside the predicted path, the method comprises automatically decreasing the vehicle speed at least in part depending on a distance of the one or more detected objects from the predicted path.In one aspect of the invention to be protected, there is provided a non-transitory carrier medium containing computer readable code for controlling a vehicle to carry out the method of another aspect.In one aspect of the invention to be protected, there is provided a computer program product executable on a processor to implement the method of another aspect.In one aspect of the invention to be protected, there is provided a computer readable medium from which the computer program product according to another aspect is loaded.In one aspect of the invention to be protected, there is provided a processor arranged to implement the method according to another aspect or the computer program product according to another aspect.Within the scope of this application, it is expressly intended that the various aspects, embodiments, examples and alternatives presented in the preceding paragraphs, in the claims and / or in the following description and drawings, and in particular their individual features, may be taken into account independently of each other or in any combination. This means that all embodiments and / or features of any embodiment may be combined in any manner and / or combination, provided that these features are not incompatible. The applicant reserves the right to alter any originally filed claim or to submit any new claim accordingly, including the right to alter any originally filed claim to depend on and / or integrate any feature of any other claim, although in this manner it has not been previously claimed.BRIEF DESCRIPTION OF THE DRAWINGSThe present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: FIG. 1 shows a schematic illustration of a vehicle according to an embodiment of the invention in plan view; FIG. 2 shows the vehicle from FIG. 1 in a side view; FIG. 3 is a high-level schematic diagram of an embodiment of the vehicle control system according to the present invention including a cruise control system and a low-speed travel control system; FIG. 4 shows a steering wheel of a vehicle according to the embodiment from FIG. 1 ; FIG. 5 shows a vehicle according to the embodiment of FIG. 1 as the vehicle (a) approaches an object and (b) passes the object and approaches a gap between two other objects; and FIG. 6 is a flow chart illustrating operation of a vehicle according to the embodiment of FIG. 1.DETAILED DESCRIPTIONReferences herein to a block, such as a function block, are intended to include references to software code for performing the function or action provided in response to one or more inputs. The code may be in the form of a software routine or function called by a host computer program, or it may be code that constitutes a portion of a stream of code that does not constitute a separate routine or function. To more easily illustrate the operation of embodiments of the invention, reference is made to a functional block.FIG. 1 shows a vehicle 100 according to an embodiment of the present invention. The vehicle 100 includes a propulsion system 129 that includes an engine 121 connected to a powertrain 130 with automatic transmission 124. It is to be understood that embodiments of the present invention are also suitable for use in manual transmission, continuously variable transmission, or other type of transmission vehicles.In the embodiment of FIG. 1, the transmission 124 may be set to one of a plurality of operating modes using a transmission mode rotary switch 124S, which are a park mode, a reverse mode, a neutral mode, a drive mode, or a sport mode. The rotary switch 124S provides an output signal to a powertrain controller 11 and, in response, the powertrain controller 11 causes the transmission 124 to operate in accordance with the selected transmission mode.The drive system 130 is arranged to drive a pair of vehicle front wheels 111, 112 using a front differential 137 and a pair of front drive shafts 118. The power plant 130 further comprises a power plant auxiliary section 131 arranged to drive a pair of rear wheels 114, 115 by means of an auxiliary drive shaft or a propeller shaft 132, a rear differential 135, and a pair of rear drive shafts 139.Embodiments of the invention are suitable for use with vehicles in which the transmission is located to drive only a pair of front wheels or only a pair of rear wheels (i.e., front drive vehicles or rear drive vehicles) or two-wheel / all-wheel drive vehicles. In the embodiment of FIG. 1, the transmission 124 is detachably connectable to the engine auxiliary portion 131 via a power transmission unit (PTU) 131P that enables operation in a two-wheel drive mode or an all-wheel drive mode. It is noted that embodiments according to the invention may possibly be suitable for vehicles having more than four wheels or in which only two wheels are driven, for example two wheels of a vehicle with three wheels or a vehicle with four wheels or a vehicle with more than four wheels.A control apparatus for the vehicle engine 121 includes a central control apparatus 10 referred to as the vehicle control apparatus (VCU) 10, the transmission control apparatus 11, a brake control apparatus 13 (an anti-lock brake system (ABS) control apparatus), and a steering control apparatus 170C. The ABS control unit 13 represents a part of a brake system 22 (FIG. 3 ). The VCU 10 receives and outputs a plurality of signals from various sensors and subsystems (not shown) provided on the vehicle. The VCU 10 includes a low-speed travel (LSP) control system 12 (which may be referred to as a low-speed control system) illustrated in FIG. 3, a stability control system (SCS) 14, a cruise control system 16, and a downhill driving assist (HDC) control system 12HD. The SCS 14 improves safety in the vehicle 100 by detecting and handling loss of traction or steering control. When a decrease in traction or steering control is detected, the SCS 14 is operable to automatically command the ABS controller 13 to apply one or more brakes of the vehicle to direct steering of the vehicle 100 in the direction the user wishes to move. In the illustrated embodiment, the SCS 14 is implemented with the VCU 10. In some alternative embodiments, the SCS 14 may be implemented by the ABS controller 13.Although not shown in detail in FIG. 3, the VCU 10 further includes a traction control (TC) function block. The TC function block is implemented in software code that is executed in a computing device of the VCU 10. The ABS controller 13 and TC function block provide outputs indicative of, for example, TC activity, activity, braking interventions on individual wheels, and engine torque requests from the VCU 10 to the engine 121 in the event of a wheel slip event. Each of the above-mentioned circumstances indicates a wheel slip event. In some embodiments, the ABS controller 13 implements the TC function block. Other vehicle subsystems, such as the control systems or similar systems, may also be included.As mentioned above, the vehicle 100 further includes a cruise control system 16 operable to automatically maintain a vehicle speed at a selected speed when the vehicle is advancing at a speed in excess of 25 km / h. The cruise control system 16 is equipped with a cruise control HMI (human machine interface) 18 whereby the user can input a target vehicle speed to the cruise control system 16 in a known manner. In an embodiment of the invention, input controls for the cruise control system are mounted on the steering wheel 171 (FIG. 5 ). The cruise control system 16 may be turned on by depressing a cruise control selection key 176. When the cruise control system 16 is turned on, pressing a "set speed" button 173 sets the current value of a cruise control set speed (cruise_set-speed) parameter to the current vehicle speed. By pressing a "+" key 174, the value for cruise_set-speed may be increased, while by pressing a "-" key 175, the value for cruise_set-speed may be decreased. A resume key 173R is provided that is operable to control the cruise control system 16 to restore the cruise control to the cruise set-speed value upon release by the driver. It should be appreciated that known highway cruise control systems, including the present system 16, are configured such that when the user applies the brake or, in manual transmission vehicles, a clutch pedal, the vehicle speed control by the cruise control system 16 is canceled and the vehicle 100 returns to a manual mode of operation requiring user input through an accelerator pedal or through a brake pedal to maintain vehicle speed. Moreover, detecting a wheel slip event, such as initiated by a loss of traction, also has the effect of cancelling control of vehicle speed by the cruise control system 16. The cruise control by the system 16 is resumed when the driver then presses the resume button 173R.The cruise control system 16 monitors the vehicle speed and any deviation from the target vehicle speed is automatically adjusted so that the vehicle speed is maintained at a substantially constant value, typically above 25 km / h. In other words, the cruise control system is ineffective at speeds below 25 km / h. The cruise control HMI 18 may be further configured to issue a warning to the user of the status of the cruise control system 16 via a visual display on the HMI 18. In the present embodiment, the cruise control system 16 is configured to allow the value for cruise_set-speed to be set to any value in the range 25-150 km / h.The LSP control system 12 further provides a speed-based control system for the user that allows the user to select a very low target speed at which the vehicle can travel without requiring pedal inputs from the user to maintain vehicle speed. Low speed (or cruise) control functionality is not provided by the highway cruise control system 16, which only operates at speeds above 25 km / h.In the present embodiment, the LSP control system 12 is activated by operating the selection button of the LSP control system 178 on the steering wheel 171. The system 12 is operable to jointly or individually apply selective control for powertrain, traction control, and brake actuation to one or more wheels of the vehicle 100.The LSP control system 12 is configured to allow a user to input a desired value for the target vehicle speed, in the form of a set speed parameter (user_set-speed), via a low-speed travel controller HMI (LSP HMI) 20 (FIGS. 1, 3 ) for which particular input buttons 173- 175 are shared with the cruise control system 16 and the HDC control system 12WD. Insofar as the vehicle speed is within the allowable range for operation of the LSP control system 12 (which in the present embodiment is in the range of 2 to 30 km / h, although other ranges are also useful) and there are no further restrictions on the vehicle speed controlled by the LSP control system 12, the LSP control system 12 regulating the vehicle speed in accordance with the LSP control system set speed value LSP_set-speed which is substantially set to the value for user_set-speed. Unlike the cruise control system 16, the LSP control system 12 is configured to operate independent of the occurrence of a traction event. That is, the LSP control system 12 does not cancel the cruise control when wheel slip is detected. Rather, the LSP control system 12 actively manages vehicle behavior when wheel slip is detected.That is, it should be appreciated that the LSP control system 12 provides torque control means for automatically causing positive or negative torque to be applied to wheels 111, 112, 114, 115 of a vehicle 100 as required to cause the vehicle 100 to advance in accordance with the set speed value LSP_set-speed, which may also be referred to as a target speed value.The LSP control HMI 20 is provided in the vehicle cabin to be easily accessible to the user. The user of the vehicle 100 may input the desired value for user_set-speed, as mentioned previously, to the LSP control system 12 via the "set speed" key 173 and the "+" / "-" keys 174, 175 in a similar manner as in the cruise control system 16. The LSP HMI 20 further includes a visual display through which information and instructions on the status of the LSP control system 12 may be output to the user.The LSP control system 12 receives input from the ABS controller 13 of the vehicle braking system 22 indicative of the extent to which the user has applied the brake via the brake pedal 163. The LSP control system 12 further receives input from an accelerator pedal 161, which indicates the extent to which the user has operated the accelerator pedal 161, and input from the transmission 124. The latter input may include signals indicative of, for example, the speed of an input shaft of transmission 124, a torque converter slip value, and a transmission ratio request. Other inputs to the LSP control system 12 include an input from the cruise control HMI 18 representative of the status (ON / OFF) of the cruise control system 16, an input from the LSP control HMI 20, and an input from a grade sensor 45 indicative of a grade of the road surface over which the vehicle 100 is driven. In the present embodiment, the gradient sensor 45 is a gyroscopic sensor. In some alternative embodiments, LSP control system 12 receives a signal indicative of road surface grade from another controller, such as ABS controller 13. The ABS controller 13 may determine a grade based on a plurality of inputs, optionally based at least in part on signals indicative of a longitudinal acceleration and a lateral acceleration of the vehicle and a signal indicative of a vehicle reference speed (v_actual), which is a signal indicative of an actual vehicle speed over the ground. Methods for calculating the reference vehicle speed, for example, based on vehicle wheel speeds, are known. The vehicle reference speed may be determined as, for example, the speed of the slowest rotating wheel or as an average speed of all wheels. Other ways to calculate the vehicle reference speed are possible suitable in some embodiments, including via a camera device or a radar sensor.The HDC system 12HD is activated by pressing a button 177 included in the HDC system HMI 20HD and attached to the steering wheel 171. When the HDC system 12WD is active, the system 12WD controls the brake system 22 to limit the vehicle speed to a value corresponding to that of an HDC set-speed parameter HDC_set-speed that can be controlled in a similar manner as the set speed of the cruise control system 16 and the LSP control system, with the same buttons 173, 173R, 174, 175. The HDC system 12HD is operable to set the value for cruise_set-speed to any value in the range 2-30 km / h. The HDC set speed parameter may also be referred to as a target HDC speed. Unless the user releases the HDC system 12WD by actuating the accelerator pedal 161 when the HDC system 12WD is active, the HDC system 12WD controls the brake system 22 (FIG. 3 ) to prevent the vehicle speed from exceeding the value HDC_set-speed. In the present embodiment, the HDC system 12WD is inoperative to apply positive drive torque. Rather, the HPC system 12WD is only operable to cause a negative brake torque to be applied via the brake system 22.It will be appreciated that the VCU 10 is configured to implement a known terrain response (TR) (RTM) system of the type described above in which the VCU 10 controls the settings of one or more vehicle systems or subsystems, such as the powertrain control system 11, depending on a selected driving mode. The driving mode may be selected by a user via a driving mode selector 141S (FIG. 1 ). The driving modes may also be referred to as terrain modes, terrain response (TR) modes, or control modes.In the embodiment of FIG. 1, four driving modes are provided: a "highway" driving mode suitable for driving on a relatively hard planar driving surface having a relatively high coefficient of friction between the driving surface and the wheels of the vehicle; a "sand" driving mode suitable for driving on sandy terrain, this is terrain characterized at least in part by a relatively high resistivity, a relatively high deformability or elasticity, and a relatively low coefficient of friction; a "grass, gravel or snow" (GGSN) driving mode suitable for driving over grass, gravel or snow which are relatively slippery surfaces (i.e., having a relatively low coefficient of friction between surface and wheel and typically less resistivity than sand); a drive mode "Creep on Rocks" (RC) suitable for slow driving on a rocky surface; and a drive mode "Match and Track Grooves" (MR) suitable for driving on matching terrain with track grooves. Other driving modes may be provided additionally or instead. In the present embodiment, the selection element 141S also allows a user to select an "automatic driving mode selection condition" operation mode in which the VCU 10 automatically selects the most suitable driving mode, as described in detail below. In some embodiments, the highway driving mode may be referred to as a "special purpose program out" (SPO) mode because it corresponds to a default driving mode and does not need to consider special factors such as a comparatively low coefficient of friction or very rough surfaces.To prevent or at least reduce passenger discomfort due to rapid changes in the acceleration rate (jerks) when the LSP control system 12 controls vehicle speed, the LSP control system 12 limits the change in the acceleration of the vehicle 100 so that it does not exceed a predetermined maximum value. The maximum allowable rate of change of the acceleration or the maximum allowable jerk value is provided by the parameter LSP_J_MAX. The LSP control system 12 further limits the maximum value of the acceleration rate to a value LSP_A_MAX.The values for LSP_A_MAX and LSP_J_MAX are set, at least in part, depending on TR mode and vehicle speed. In some embodiments, including the present embodiment, the values for TR_mode=Sand are higher than the corresponding values for TR_mode=SPO, GGSN, or MR due to the higher resistance on a vehicle 100 travelling through sand as compared to a vehicle travelling on a dry asphalt highway surface, a grass, gravel, or snow surface, or on a matching surface or on a surface with track grooves.The LSP control system 12 causes the vehicle 100 to operate in accordance with the value for LSP_set-speed.To effect the application of the required positive or negative torque, the VCU 10 may cause positive or negative torque to be applied to the vehicle wheels via the powertrain 129, and / or a braking force to be applied to the vehicle wheels via the brake system 22, either or both of which may be employed to implement the change in torque required to maintain a required vehicle speed. In some embodiments, torque is individually applied to the vehicle wheels, for example, by powertrain torque vectoring, to maintain the vehicle at the required speed. Alternatively, in some embodiments, torque may be applied to the wheels together, for example, in vehicles with propulsion systems where torque vectoring is not possible. In some embodiments, the powertrain controller 11 may be operable to implement torque vectoring to one or more wheels by controlling a power plant component, such as a rear drive unit, a front drive unit, a differential, or another suitable component. For example, one or more components of the propulsion system 130 may include one or more clutches operable to enable a particular torque to be applied to one or more wheels to be varied. Other arrangements may also be suitable.When a powertrain 129 includes one or more electric machines, for example one or more prime movers and / or generators, the powertrain controller 11 may be operable to modulate torque applied to one or more wheels to implement torque vectoring via one or more electric machines.In some embodiments, the LSP control system 12 may receive a wheel_slip signal (also labeled 48 in FIG. 3 ) indicative of an occurring wheel slip event. The signal 48 is also provided in the vehicle's highway cruise control system 16, which in the latter case initiates a cancellation or cancellation mode of operation in the highway cruise control system 16 such that automatic control of vehicle speed by the highway cruise control system 16 is interrupted or cancelled. However, the LSP control system 12 is not arranged to abort or interrupt operation upon receipt of the wheel_slip signal 48. Rather, the system 12 is arranged to monitor and then manage wheel slip to reduce the workload of the driver. During a wheel slip event, the LSP control system 12 continues to compare the measured vehicle speed with the value LSP_set-speed, and continues to automatically regulate torque applied to the vehicle wheels (via the powertrain 129 and the brake system 22) to maintain the vehicle speed at the selected value. Thus, it is noted that the LSP control system 12 is configured differently from the cruise control system 16 for which wheel slip occurrence has the effect that the effect of canceling the cruise control function so that the manual operation of the vehicle can be resumed, or that the cruise control can be resumed by pressing the resume key 173R or the set speed key 173 by the cruise control system 16.The vehicle 100 is further provided with additional sensors (not shown) that represent various parameters associated with vehicle motion and status. These may be inertial systems that apply exclusively to the LSP or HDC control systems 12, 12WD, or a portion of an occupant restraint system, or any other subsystem that may provide data from sensors such as gyroscopes and / or accelerometers that may indicate vehicle body motion and provide useful input to the LSP and / or HDC control system 12, 12WD. The signals from the sensors provide or are used to calculate a plurality of driving condition indicators (also referred to as terrain indicators) that indicate the nature of the terrain conditions over which the vehicle 100 is moving.Sensors (not shown) on vehicle 100 include, but are not limited to, sensors that output persistent sensor outputs to VCU 10, including wheel speed sensors as mentioned above, an ambient temperature sensor, an ambient pressure sensor, tire pressure sensors, wheel joint sensors, gyroscopic sensors for sensing vehicle yaw, roll, and pitch angles and rates, a vehicle speed sensor, a longitudinal acceleration sensor, an engine torque sensor (or engine torque estimator), a steering angle sensor, a steering angle speed sensor, a pitch angle sensor (or pitch estimator), a lateral acceleration sensor, which may be part of SCS 14, a brake pedal position sensor, a brake pressure sensor, an accelerator pedal position sensor, longitudinal, lateral, and vertical motion sensors, and water detection sensors, forming a part of a vehicle wart assist system (not shown). In other embodiments, only a selection of the above sensors may be employed.The VCU 10 further receives a signal from the steering controller 170C. The steering controller 170C is in the form of an electronic power steering unit (ePAS) 170C. The electronic control unit 170C provides a signal to the VCU 10 indicative of the steering force applied to steerable road wheels 111, 112 of the vehicle 100. The force corresponds to that applied to the steering wheel 171 by a user in combination with the steering force generated by the ePAS unit 170C. The ePAS unit 170C further provides a signal representative of a steering wheel rotational position or steering angle.In the present embodiment, the VCU 10 evaluates the various sensor inputs to determine the probability that each of the plurality of TR modes (control modes or driving modes) will be appropriate for the vehicle subsystems, each control mode corresponding to a particular type of terrain over which the vehicle is driving (e.g., match and track grooves, sand, grass / gravel / snow) as described above.When the user has selected the operation of the vehicle in the automatic driving mode selection state, the VCU 10 selects the most suitable one of the control modes and is configured to automatically control the subsystems in accordance with the selected mode. This aspect of the invention is described in more detail in our co-pending patent applications GB2492748, GB2492655 and GB2499279, the contents of which are incorporated herein by reference as previously stated.As previously indicated, the condition of the terrain in which the vehicle is driven (as determined with reference to the selected control mode) may be employed in the LSP control system 12 to determine an appropriate increase or decrease in vehicle speed. For example, if the user selects a user_set-speed value that is inappropriate for the condition of the terrain in which the vehicle is driven, the system 12 is operable to automatically set the value for LSP_set-speed to a value below user_set-speed. For example, in some cases, the user-selected speed may not be achievable or unsuitable for particular terrain, particularly uneven or rough terrain. If the system 12 selects a set speed (a value for LSP_set-speed) that is different from a user-selected set speed user _set-speed, then a visual indication of the speed limit is provided to the user via the LSP HMI 20 to indicate that an alternative speed has been accepted.Other arrangements may also be suitable.In the present embodiment, the vehicle 100 is equipped with a stereoscopic camera system 185C to generate stereo color image pairs using a pair of color video cameras. A stream of dual video image data is fed from the cameras to the VCU 10, which processes the received image data to generate a 3D point cloud dataset. The path of the vehicle with respect to the 3D point cloud path is also predicted. This can be achieved with any path prediction technology based on the 3D point cloud dataset or the images of the video camera to determine the most likely vehicle path. The predicted path may be determined using an algorithm that analyzes features of the image data or cloud of points to detect the presence of a road or road that the vehicle 100 appears to follow. Alternatively, in a simple version, the path prediction may be based solely on a measured steering angle and on the current location of the vehicle with respect to the 3D point cloud. Optionally, a combination of steering angle and path prediction based on the point cloud may be employed. The predicted path is defined with reference to the centerline of a path that the vehicle 100 is to follow and includes the area swept by the vehicle 100 as it is driven over the predicted path. Thus, the width of the predicted path substantially corresponds to the width W of the vehicle 100. In the embodiment of FIG. 1, the vehicle 100 has a wheel base L. The steering angle may be based on driver input or, when the vehicle is autonomously moving, steering requests from a vehicle controller.Once the predicted path is identified, the VCU 10 determines whether relevant objects are present in front of the vehicle 100 but outside of the predicted path of the vehicle 100. The VCU 10 uses detection means provided by an algorithm to detect all relevant objects in front of the vehicle 100 based on the 3D point cloud. The size of any such relevant objects and their distance from the predicted path is estimated by the VCU 10 and it is determined whether the presence of any relevant objects justifies a reduction in vehicle speed. Thus, the VCU 10 provides determining means for determining whether one or more objects detected by means of the detecting means are outside the predicted path.In the present embodiment, the VCU 10 is configured to consider objects as relevant only when they are greater than a predetermined height and within a predetermined distance from the vehicle 100. In the present embodiment, the predetermined height is about 0.5 m, although other values of a predetermined height may be employed in some embodiments. The predetermined distance is 5 m in the present embodiment, although other distances may be useful.In the present embodiment, when the VCU 10 has determined that there is no relevant object in front of the vehicle, the VCU 10 is configured to set an allowable maximum value for LSP_set-speed, LSP_set-speed_max to be used in the LSP control system 12 and the HDC control system 12HD.In the present embodiment, the value for LSP_set-speed_max is at least partially dependent on the distance of any relevant objects from the predicted path and the estimated height of those relevant objects. The greater the height of the relevant object, the lower the value for LSP_set-speed_max, i.e., the higher the value by which the LSP_set-speed_max is below the value for LSP_set-speed that was inserted before decreasing the value. Similarly, the value for LSP_set-speed_max decreases as the distance of a relevant object from the predicted path decreases.For example, the value for LSP_set-speed may be decreased by a lesser value when the predicted path passes through an opening in a comparatively low wall (where the driver's view of objects behind the wall is comparatively unobstructed), or by a greater value when the predicted path passes through an opening of similar size in a comparatively high wall (which more obstructs the driver's view of objects behind the wall). Similarly, the value for LSP_set-speed may be decreased by a larger value as the vehicle 100 approaches a comparatively high tree that is comparatively close to the predicted path, compared to a case where a comparatively low busch is similarly close to the predicted path.In the present embodiment, the VCU 10 calculates a value for LSP_set-speed_max to be input to the LSP control system 12 based on the object height H, the object distance D from the predicted path, and the current value for LSP_set-speed. The value for LSP_set-speed_max is determined according to the invention by multiplying the current value for LSP_set-speed by an object proximity reduction factor which is less than one, so that the value for LSP_set-speed_max is always less than the value for LSP_set-speed, the value for the object proximity reduction factor depending on the value for object height H and distance D from the predicted path.In some alternative embodiments, the value for LSP_set-speed_max is derived from the distance of a relevant object from the predicted path and the height of the object using a look-up table. If the current value for LSP_set-speed is less than the value for LSP_set-speed _max from the look-up table, or equal, then no reduction of LSP_set-speed is performed.In some embodiments, the object proximity reduction factor is further dependent on the TR mode in which the vehicle 100 is currently operating. In some embodiments, the amount of deceleration is lower when the vehicle is operating in the SPO (Highway) TR mode compared to the GGSN, MR, and RC modes. This is because when the vehicle 100 is in the SPO mode, it is expected to be driven on comparatively surfaces having a comparatively high friction coefficient. In the case of modes GGSN and MR, the vehicle 100 is expected to be driven on a comparatively slippery surface, while in mode RC, the vehicle 100 is expected to be driven on a comparatively rough surface. It should be appreciated that other arrangements may be suitable in some embodiments.When it is determined that one or more relevant objects are present, the VCU 10 calculates a value for LSP_set-speed_max for each relevant object. The VCU 10 then regulates the value for LSP_set-speed such that the speed of the vehicle 100 does not exceed the value for LSP_set-speed_max calculated for each relevant object when the vehicle 100 reaches a position where a foremost portion of the vehicle 100 is at the same height as the corresponding relevant object.It should be appreciated that, as previously indicated, the value for LSP_set-speed used by the VCU 10 may be lower than the user-requested value, user_set-speed, for example, depending on one or more factors, such as roughness of the surface over which the vehicle 100 is driven to control occupant comfort. This latter reduction may be automatically implemented by the LSP control system 12 regardless of the presence of relevant objects in front of the vehicle 100. Thus, some embodiments of the invention have the feature that the value for LSP_set-speed is further decreased when a relevant object is detected. The reduction occurs when the vehicle 100 is sufficiently close to the object even if the value for LSP_set-speed by the occupant comfort LSP control system 12 is already set lower than the value for user_set-speed.In the present embodiment, the VCU 10 is configured to determine, for each relevant object in front of the vehicle 100, the required distance to cause the vehicle 100 to slow from a speed corresponding to the predominant value for LSP_set-speed (which may be less than but not greater than the value for user_set-speed) or the actual value of the vehicle speed, when different from the predominant value for LSP_set-speed, to a speed corresponding substantially to LSP_set-speed_max once the vehicle 100 is within a predetermined distance from a location on the predicted path at which a foremost portion of the vehicle 100 is at the same height as the relevant object. In the present embodiment, the predetermined distance is calculated at least in part depending on the value for LSP_set-speed and LSP_set-speed_max, wherein the predetermined distance is greater than the difference between LSP_set-speed and LSP_set-speed_max.The VCU 10 determines the distance required to decelerate the vehicle 100 from the current value LSP_set-speed to the new value LSP_set-speed_max, with reference to stored maximum allowable rate values for acceleration / deceleration of the vehicle 100 controlled by the LSP control system 12, LSP_A_MAX, and the corresponding maximum allowable rate of change value for acceleration (or jerks), LSP_J_MAX, for the predominant TR mode. The LSP control system 12 then begins to slow the vehicle 100 at a sufficient distance from the relevant object to allow the speed to decrease to the value LSP_set-speed_max at the time the vehicle 100 is within the predetermined range of the relevant object.In the present embodiment, the VCU 10 calculates the predetermined distance, s, at which the deceleration should be started according to the equation: here, v=current vehicle speed, u=minimal allowable value for LSP_set-speed, a= L_A_MAX, and d=buffer distance from the relevant object at which the vehicle 100 will have decelerated to the decreased speed LSP_set-speed_max.The deceleration is initiated by setting the value for LSP_set-speed to the value LSP_set-speed_max. The LSP control system 12 then automatically causes the vehicle speed to be decreased to a value substantially corresponding to LSP_set-speed= L_set-speed_max, as described above.It should be appreciated that the values for LSP_A_MAX and LSP_J_MAX may be dependent, at least in part, on the predominant measured or estimated value of the coefficient of friction, as well as on the TR mode in which the vehicle 100 is operating. This feature has the advantage that a likelihood that the vehicle 100 experiences wheel slip may be reduced.It should be noted that when a relevant object is detected, the actual value for the vehicle speed may be different from the predominant value for LSP_set-speed. For example, a user may have recently increased or decreased the value for user_set-speed, resulting in a change in the value for LSP_set-speed, and the LSP control system 12 may be engaged in bringing the actual vehicle speed to the new value for LSP_set-speed. The VCU 10 is configured to consider any such differences between actual speed and LSP_set-speed, and ensure that the vehicle 100 can slow down to an actual speed that does not exceed LSP_set-speed_max when the vehicle 100 reaches the predetermined distance from the next relevant object. In the present embodiment, the value for LSP_set-speed_max is calculated based on the value for LSP_set-speed at which the LSP control system 12 attempts to operate the vehicle 100 when identifying one or more relevant objects.It should be appreciated that the LSP control system 12 may attempt to employ a value for LSP_set-speed in the absence of relevant objects, for example, taking into account occupant comfort, and to employ an updated value for LSP_set-speed_max by the LSP control system 12, given any changes in the value for LSP_set-speed to be employed in the absence of any relevant objects. In some embodiments, the LSP controller 12 may be configured to not allow a changed value to be used for LSP_set-speed_max that is higher than the value currently used when the vehicle 100 is within the predetermined range of a relevant object.It should be noted that after reducing the vehicle speed to LSP_set-speed_max, the VCU 10 continues to prevent the value of LSP_set-speed from exceeding LSP_set-speed_max until the vehicle 100 has passed the relevant object. However, based on the 3D point cloud data captured by camera system 185C and, if available, using data attached to vehicle 100 at corresponding locations around the periphery of vehicle 100 and obtained in the following described in more detail by proximity sensors 191, VCU 10 attempts to repeatedly refine the value of LSP_set-speed_max as vehicle 100 approaches the relevant object. The proximity sensors 191 thus allow the LSP adjustment speed to be refined and the method generally can be performed even when the object has moved out of the field of view of the camera system 185C. As described in greater detail below, the proximity sensors enable the LSP control system 12 to track and identify the object when the vehicle has passed the object sufficiently far to end the temporary reduction of LSP_set-speed_max and return to the previous value for LSP_set-speed.FIG. 5( a) shows a vehicle 100 traveling on a road or a route R. At the illustrated location of the vehicle 100, the VCU 10 has determined that the predicted path of the vehicle corresponds to the dashed line PP. The VCU 10 has determined that there are three relevant objects in front of the vehicle, shown at 195A, 195B, and 195C. The VCU 10 has further calculated the height H of each relevant object and the distance D of each object from a center line of the predicted path PP. Note that, as stated above, the predicted path PP in the present embodiment is defined as the area swept by the moving vehicle 100 with reference to the center line of the path to be followed by the vehicle 100. The distance of an object from the predicted path PP may be considered to correspond to the following value: the distance D of the object from the center line of the predicted path minus half of the width W of the vehicle, i.e., (D-W / 2).As the vehicle 100 approaches the first relevant object 195A, the VCU 10 causes the vehicle speed to decrease to a value LSP_set-speed_max before the vehicle 100 reaches the relevant object 195A. As the vehicle 100 approaches and passes through the relevant object 195A, as illustrated in FIG. 5( b), the VCU 10 in the present embodiment uses a set of proximity sensors 191 attached to the vehicle 100 at corresponding locations around the periphery of the vehicle 100 to detect the object 195A. Thus, the VCU 10 is able to capture when the vehicle 100 has passed the relevant object 195A, even if the object may no longer be visible to the stereoscopic camera system 185C. Once the vehicle 100 has passed the object 195A, the VCU 10 causes the vehicle 100 to resume operation at a value for LSP_set-speed that substantially corresponds to user_set-speed, unless a lower value is deemed more suitable by the LSP control system 12 due to comfort conditions as described above.In the case of the scenario illustrated in FIG. 5, at the location of the vehicle 100 shown in FIG. 5( b), the two foremost proximity sensors 191 on the left side of the vehicle 100 have detected the presence of the first relevant object 195A. The VCU 10 tracks the path of the object 195A past the vehicle 100 using the sensors 191 on the side of the vehicle 100 on which the object 195A is located. Once the VCU 10 determines that the vehicle 100 has passed the object 195A, the LSP control system 12 is then permitted to set the value for LSP_set-speed to a higher value that is higher than LSP_set-speed_max, as appropriate.In the scenario depicted in FIG. 5 (b), it can be seen that the relevant objects 195B, 195C detected by the VCU 10 define a gap G through which the vehicle 100 must fit. In the present embodiment, the VCU 10 is configured such that when two or more relevant objects are detected in front of the vehicle 100 with substantially the same distance from the vehicle 100 with respect to the center line of the predicted path PP, and at least one object is present on each side of the predicted path PP, the VCU 10 determines the size of the gap G between the objects. In the present embodiment, the VCU 10 calculates the average distance of the objects 195B, 195C from the predicted path, (G-W) / 2, where W is the width of the vehicle 100. The VCU 10 then calculates the value for LSP_set-speed_max that would be employed if the vehicle 100 passed a single object that is one-half this average distance from the vehicle 100, i.e., a distance (G-W) / 4 from the vehicle 100. The value for LSP_set_speed is then regulated such that the vehicle speed does not exceed this value for LSP_set-speed_max as the vehicle 100 approaches and passes the gap.In some alternative embodiments, the VCU 10 uses a separate look-up table to determine the value for LSP_set-speed_max when the predicted path passes through a gap between relevant objects.As the vehicle 100 approaches a relevant object 195, the VCU 10 monitors the proximity of the vehicle 100 to the object 195 and may further decrease the value for LSP_set-speed_max as the vehicle 100 approaches the object 195, depending on the object from the predicted path PP. It should be noted that the predicted path PP is refined repeatedly as the vehicle 100 travels, thereby enabling more accurate determination of the distance of a relevant object 195 from the predicted path PP as the vehicle 100 approaches the object 195.It should be appreciated that if it is determined that there are multiple objects 195 (or obstacles 195), the VCU 10 may individually calculate a value for LSP set-speed_max for each object 195 (or obstacle 195) in front of the vehicle 100. Moreover, when there is a gap G between two or more objects 195 that will be passed at substantially the same position along predicted paths PP, the VCU 10 may calculate another value for LSP_set-speed_max in consideration of the size of the gap G as described above. The VCU 10 may compare the value for LSP_set-speed_max calculated in consideration of the gap G with values for LSP_set-speed_max calculated based on the fact that the objects 195 are isolated, and set the value for LSP_set-speed_max to the smaller of the values for LSP_set-speed_max calculated in this manner. This feature has the advantage that when the vehicle 100 passes through the gap closer to one object 195 than the other, resulting in a value for LSP_set-speed_max that is less than calculated for the gap G, the value for LSP_set-speed_max can be set to the lower value.It should be appreciated that the value of LSP_set-speed_max v may be dependent on one or more factors, such as a parameter, factor, or setting related to a driver desired ride comfort level. For example, the vehicle may include a driver-operable control element, such as a rotary switch or a touchscreen interface function, that enables a driver to specify the level of ride comfort desired for the vehicle occupants. The VCU 10 may set the value for LSP_set-speed_max, at least in part, depending on the desired comfort level indicated by the driver-operated operator. For example, one or more look-up tables may be provided that allow the VCU 10 to determine the required value for LSP_set-speed_max as a function of the desired level of comfort indicated by the driver-operated operator.FIG. 6 is a flowchart illustrating the method of vehicle control implemented by the present embodiment.In step S 101, the VCU 10 analyzes the video stream received from the camera system 185C to identify the presence of relevant objects 195.In step S 103, the VCU 10 determines whether relevant objects 195 are present in the image data. If such objects 195 are present, the VCU 10 proceeds to step S 105, otherwise the VCU 10 proceeds to step S 101.In step S 105, the VCU 10 calculates a value for LSP_set-speed_max with respect to each relevant object 195.In step S 107, the VCU 10 calculates the value for the predetermined range of each object 195 identified in step S 101 at which the speed needs to be reduced to the value for LSP_set-speed_max corresponding to each object 195.In step S 109, the VCU 10 determines the position along the predicted path PP at which the deceleration is required to start.In step S 111, the VCU 10 determines whether the vehicle 100 has reached or passed the location where the deceleration is to start. If the vehicle 100 has not reached this location, the VCU 10 repeats step S 111, otherwise the VCU 10 proceeds to step S 113.In step S 113, the VCU 10 sets the value for LSP_set-speed substantially equal to LSP_set-speed_max because the vehicle 100 has now reached or passed the location where the speed reduction is to begin. It should be noted that in certain situations, the VCU 10 may determine that a relevant object 195 is present in front of the vehicle 100 if there is not sufficient time available to reduce the vehicle speed to the value LSP_set-speed_max before the object 195 is reached. Nevertheless, the VCU 10 sets the value of LSP_set-speed to LSP_set-speed_max, and uses the maximum allowable deceleration rate to decrease the vehicle speed.In step S 115, the VCU 10 attempts to detect the relevant object 195 using proximity sensors 191 while the vehicle 100 is passing the object 195.In step S 117, the VCU 10 determines whether the relevant object 195 has been detected at the expected location. If this is not the case, the VCU 10 proceeds to step 125 on the assumption that the object 195 has most likely been incorrectly recognized and does not exist. If the object 195 has been detected, the VCU 10 proceeds to step S119.In step S 119, the VCU 10 attempts to track the position of the relevant object 195 with respect to the vehicle 100 using proximity sensors 191 as the vehicle 100 passes the object 195. If the VCU 10 determines that the object 195 can no longer be tracked with the sensors 191 before the sensors 191 indicate that the vehicle 100 has passed the object, the VCU 10 monitors the distance travelled by the vehicle 100 beyond the last known position of the object 195.In step S 121, the VCU 10 determines whether the proximity sensors 19 indicate that the vehicle 100 has passed the object 195. If the sensors 191 indicate that the vehicle 100 has passed the object 195, the VCU 10 proceeds to step S 125; otherwise, the VCU 10 proceeds to step S 123.In step S 123, the VCU 10 determines whether the vehicle has already moved two vehicle lengths beyond the last known location of the object. If the vehicle 100 has not yet moved beyond this distance, the VCU 10 continues to step S 119; otherwise, the VCU 10 continues to step S 125.In step S125, the value for LSP_set-speed is no longer limited to LSP_set-speed_max.Some embodiments of the invention enable vehicle operation with higher silence in approaching objects near a predicted path by reducing the workload of the driver. This is because the driver does not need to manually decrease the value for user_set-speed to decrease the vehicle speed as it approaches objects that are close to a predicted path, or to override the regulation of the vehicle speed by the LSP control system 12, the vehicle speed appears too high as it approaches these objects. Rather, the vehicle 100 proactively detects the presence of objects in the vicinity of the predicted path and decreases the speed accordingly.It should be appreciated that some embodiments of the invention have the advantage that sudden overbraking by a driver in high resistance terrain, such as sand, may be prevented in response to the presence of one or more objects near the predicted path of the vehicle 100. This is because the vehicle 100 automatically causes a decrease in speed, if necessary, so that one or more objects are passed at a speed at which the driver is more likely to feel comfortable. Some embodiments of the invention result in significantly higher quietness of the vehicle when driving over variable terrain with objects such as trees, rocks or rocks near the predicted path.It is to be understood that the above-described embodiments are given by way of example only and are not intended to limit the invention, the scope of which is defined in the appended claims.Throughout the specification and claims of this specification, the words "comprise" and "include", and variations of the words such as "comprising" or "comprises" mean "including, but not limited to", and are not intended to exclude (and not exclude) other parts, additives, components, numbers, and steps.In the specification and claims of this specification, the singular includes the plural, unless otherwise required by context. In particular, it is to be understood that when indefinite articles are employed, the specification is to be understood as including both plural and singular, unless otherwise required by context.Features, integers, characteristics described in connection with a particular aspect, embodiment, or example of the invention are considered applicable to any other aspect, embodiment, and example unless otherwise incompatible.

Claims

A control system (10) for a vehicle (100) comprising: torque control means for automatically causing positive or negative torque to be applied to one or more wheels of a vehicle (100) as required to cause a vehicle (100) to move in accordance with a target speed value; path prediction means for predicting a path of the vehicle (100) in a direction of movement; detection means for detecting one or more objects (195, 195A-C) in front of the vehicle (100); determination means for determining whether one or more objects (195, 195A-C) detected by the detection means are outside the predicted path; and control means configured to automatically temporarily reduce vehicle speed when the one or more detected objects (195, 195A-C) is determined to be outside the predicted path, at least in part depending on a distance of the one or more detected objects (195, 195A-C) from the predicted path; wherein decreasing the vehicle speed comprises the control means limiting the vehicle speed to a speed limit and wherein the predetermined speed limit is determined by multiplying a current speed value by an object proximity reduction factor less than one, wherein a value of the object proximity reduction factor is dependent on the distance of the one or more detected objects (195, 195A-C) from the predicted path and a height of the one or more detected objects (195, 195A-C).The control system (10) of claim 1, wherein automatically decreasing the vehicle speed comprises the control means decreasing the vehicle speed in the event that one or more detected objects (195, 195A-C) are at a predetermined distance from the predicted path.The control system (10) of claim 1 or 2, wherein the greater the height of the one or more detected objects (195, 195A-C), the lower the speed limit.The control system (10) of any preceding claim, wherein the speed limit is arranged to also decrease as the distance of the one or more detected objects (195, 195A-C) from the predicted path decreases.The control system (10) of claim 4 operable to determine a distance from which to begin the temporary reduction of the vehicle speed.The control system (10) of claim 4 or 5, wherein the speed limit is a predetermined speed limit.A control system (10) according to any preceding claim, wherein automatically decreasing the vehicle speed comprises the control means decreasing the vehicle speed at least in part depending on the identity of a selected one of a plurality of driving modes in which the vehicle (100) is operating.The control system (10) of claim 7, wherein in each driving mode, at least one of a plurality of vehicle subsystems is caused to operate in a predetermined one of a plurality of configuration modes of that subsystem, the subsystem configuration mode being determined in dependence on the selected driving mode.The control system (10) of claim 7 or 8, wherein the subsystems include a powertrain subsystem, a brake subsystem, and / or a suspension subsystem.The control system (10) of any preceding claim, wherein the torque control means comprises an electrical controller configured to communicate with a powertrain controller (11) and a brake controller (13).The control system (10) of any preceding claim, further configured to temporarily automatically decrease the vehicle speed further in response to a comfort indicator generated in response to a control input provided by a user.A control system (10) according to any preceding claim, wherein the control system comprises: an electronic processor to receive information from the sensing means indicating that one or more sensed objects (195, 195A-C) are present in front of the vehicle (100); and an electronic storage device electrically coupled to the electronic processor and having instructions stored thereon, the processor configured to access the storage device and execute the instructions stored therein such that it is operable to: cause a positive or negative torque to be applied to one or more wheels of a vehicle (100) to cause a vehicle (100) to move in accordance with a desired speed value; predict a path of the vehicle (100) in a direction of movement; and determining whether one or more objects detected by the detecting means (195, 195A-C) are outside the predicted path and, depending at least in part on a distance of the one or more detected objects (195, 195A-C) from the predicted path, automatically temporarily decreasing the vehicle speed when it is determined that the one or more detected objects (195, 195A-C) are outside the predicted path.The control system (10) of any preceding claim, wherein the sensing means comprises a stereoscopic camera (185C) or a lidar system.The control system (10) of any preceding claim, further comprising a proximity sensor (19, 191).The control system (10) of claim 14, wherein the control means is configured to predict the decreased vehicle speed based on data from the proximity sensor (19, 191).The control system (10) of claim 14 or 15, wherein the control means is configured to determine when the vehicle (100) has passed the object (195, 195A-C) and increase the vehicle speed.The control system (10) according to any one of the preceding claims, wherein the path prediction means for predicting a path of the vehicle (100) in a direction of movement is configured to receive image data, cloud point data and / or steering angle data.A vehicle (100) comprising a control system (10) according to any preceding claim.A method of controlling the speed of a vehicle (100) implemented using a control system (10), comprising: automatically causing a positive or negative torque to be applied to one or more wheels of a vehicle (100) to cause a vehicle (100) to move in accordance with a desired speed value; and predicting a path of the vehicle (100) in a direction of movement; and determining whether one or more detectable objects (195, 195A-C) are present in front of the vehicle (100); wherein the method further comprises determining whether one or more detectable objects (195, 195A-C) are present in front of the vehicle (100) outside the predicted path, wherein if it is determined that one or more detectable objects (195, 195A-C) are present in front of the vehicle (100) and are outside the predicted path, the method comprises automatically temporarily decreasing the vehicle speed at least in part depending on a distance of the one or more detected objects (195, 195A-C) from the predicted path; wherein decreasing the vehicle speed comprises the control means limiting the vehicle speed to a speed limit and wherein the predetermined speed limit is determined by multiplying a current speed value by an object proximity reduction factor less than one, wherein a value of the object proximity reduction factor is dependent on the distance of the one or more detected objects (195, 195A-C) from the predicted path and a height of the one or more detected objects (195, 195A-C).A non-transitory computer readable carrier medium containing computer readable code for controlling a vehicle (100) to perform the method of claim 19.A computer program product executable on a processor to implement the method of claim 19.A computer readable medium having loaded thereon the computer program product of claim 21.A processor arranged to implement the method of claim 19 or the computer program product of claim 21.

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