Speed control system and method for vehicle

Abstract

Aspects of the invention relate to a speed control system (15) for a vehicle (10), a method and a vehicle (10). The system causes the vehicle (10) to drive at the target speed value. A speed control system (15) receives a turn indicator status signal indicative of a condition of a turn signal indicator control of a vehicle. The system (15) determines a turn indicator target speed limit from the turn indicator status signal and controls the vehicle according to the turn indicator target speed limit.

Description

Technical Field

[0001] The present disclosure relates to a control system and method for a vehicle. Aspects of the present invention relate to a speed control system for a vehicle, a system for controlling the speed of a vehicle, a vehicle, a method of controlling the speed of a vehicle, and a non-transitory computer readable storage medium.

[0002] The contents of WO 2013 / 124321 are hereby incorporated by reference. Background Art

[0003] It is known to provide speed control systems for vehicles, in particular speed control systems for causing a vehicle to operate in accordance with a target speed value. It is desirable to provide an improved speed control system for assisting a driver in traversing terrain.

[0004] It is an object of the present invention to address one or more of the disadvantages associated with the prior art. Summary of the invention

[0005] Aspects and embodiments of the present invention provide a speed control system, a system for controlling the speed of a vehicle, a vehicle and a method of controlling the speed of a vehicle as claimed in the accompanying claims.

[0006] According to one aspect of the present invention, there is provided a speed control system for a vehicle, the speed control system being configured to cause the vehicle to operate according to a target speed, the speed control system comprising one or more controllers, the speed control system being configured to:

[0007] receiving a turn indicator status signal indicating a condition of a turn signal indicator control of the vehicle;

[0008] determining a turn indicator target speed limit based on the turn indicator status signal; and

[0009] The vehicle is controlled according to the turn indicator target speed limit.

[0010] Embodiments of the present invention provide advantages of vehicle stability and reduced driver workload. This is at least in part because the applicant has recognized that by automatically reducing speed based on the vehicle's turn indicator status, excessive braking immediately before a turn can be avoided because the vehicle automatically reduces speed before the turn when a left turn indicator or a right turn indicator is selected. By triggering a speed reduction in response to turn indicator information, user enjoyment can be improved.

[0011] Optionally, the speed control system is configured to receive a terrain indicator parameter indicative of a property of terrain on which the vehicle is travelling, wherein the turn indicator target speed limit is determined in dependence on the terrain indicator parameter.

[0012] An advantage of this feature is that the speed can be reduced to a speed suitable for initiating a turn on the terrain the vehicle is traveling on. The turn indicator target speed limit may be lower for relatively slippery and / or brittle surfaces such as grass, gravel or snow than for less slippery and / or more stable surfaces such as asphalt or concrete.

[0013] Optionally, the terrain indicator parameters are determined according to:

[0014] a signal indicating the driver's selection of terrain type; or

[0015] A signal indicative of terrain type generated by another vehicle system based on vehicle sensor information.

[0016] A system that selects or automatically identifies the type of terrain (or nature of terrain) does not form part of the present invention, but generally allows for differentiation of surfaces such as rock, mud, sand, and snow to better adapt the vehicle systems to the terrain on which the vehicle is traveling. The signal indicative of the driver's selection of the type of terrain may, for example, be a signal indicative of the driving mode in which the vehicle is operating, such as a terrain response (TR) mode. The TR mode may, for example, be a TR mode selected by the driver or a TR mode automatically selected by the vehicle based on vehicle sensor information.

[0017] Optionally, the speed control system is configured to receive an occupant comfort parameter indicative of a desired occupant comfort level, and wherein the turn indicator target speed limit is further determined at least in part based on the occupant comfort parameter.

[0018] The advantage of this feature is that it can enhance user enjoyment because the vehicle speed can be closely aligned with the occupant's expectations. It will be appreciated that in some embodiments, selecting an increased comfort level will reduce the turn indicator target speed limit. However, this may have the disadvantage of increased travel time. Therefore, the user can set the desired comfort value according to their preferences.

[0019] Optionally, the speed control system is configured to receive map information indicating a geographical location of one or more paths ahead of the vehicle, wherein the turn indicator target speed limit is determined based on the map information.

[0020] Optionally, the speed control system is configured to:

[0021] determining a predicted route for the vehicle based on the map information and the turn indicator status signal; and

[0022] Determine turn indicator target speed limits based on predicted routes.

[0023] Optionally, the turn indicator state signal comprises a left turn indicator state signal or a right turn indicator state signal, and the speed control system is configured to:

[0024] determining a predicted route of the vehicle based on the map information and the left turn indicator status signal or the right turn indicator status signal; and

[0025] Determine turn indicator target speed limits based on predicted routes.

[0026] It will be appreciated that in the event that there is an intersection ahead of the vehicle, the turn indicator state signal can help the speed control system predict the likely path of the vehicle when it reaches the intersection. Thus, when the intersection is reached, the speed control system can set the turn indicator target speed limit to a value appropriate for the predicted path of the vehicle.

[0027] Optionally, the speed control system is configured wherein the lower the turn indicator target speed limit, the sharper the turn predicted to be made on the predicted route.

[0028] Optionally, the speed control system is configured to:

[0029] receiving vehicle turn information indicating that the vehicle is turning; and

[0030] Limit vehicle speed based on vehicle turning information.

[0031] It will be appreciated that turning information refers to information regarding a turn of the vehicle about an axis that is substantially vertical relative to the vehicle, which is an axis that is perpendicular to the longitudinal and lateral axes of the vehicle.

[0032] Optionally, the vehicle turning information includes information indicating at least one of the following:

[0033] The vehicle's lateral acceleration; and

[0034] The vehicle's yaw rate,

[0035] The speed control system is configured to limit vehicle speed based at least in part on one or both of vehicle lateral acceleration and yaw rate.

[0036] It will be appreciated that the speed control system may be configured to at least partially limit the vehicle speed to a vehicle turning speed limit when the lateral acceleration or yaw rate exceeds a respective predetermined value for a respective predetermined period of time. In addition to or in lieu of the lateral acceleration and / or yaw rate information, the vehicle turning information may include information indicative of a steering wheel position, vehicle path information such as information indicative of a radius of curvature of the vehicle path, or any other suitable information.

[0037] The vehicle turning speed limit may be determined based at least in part on the lateral acceleration rate, the vehicle turning speed limit value being lower for higher values ​​of the lateral acceleration rate than for lower values ​​of the lateral acceleration rate.

[0038] The vehicle turning speed limit value may be determined based at least in part on the yaw rate, the vehicle turning speed limit value being lower for higher values ​​of yaw rate than for lower values ​​of yaw rate.

[0039] Optionally, the speed control system is configured to limit the vehicle speed based on the vehicle turn information and terminate limiting the vehicle speed to the turn indicator target speed limit when the vehicle turn information indicates that the vehicle speed should be reduced to a value equal to or less than the turn indicator target speed limit.

[0040] Optionally, the speed control system is configured wherein, when the speed control system terminates limiting the vehicle speed to the turn indicator target speed limit, the speed control system subsequently does not permit limiting the vehicle speed to the turn indicator target speed limit until after the turn indicator status signal indicates that the condition of the turn indicator corresponds to neither a left turn nor a right turn.

[0041] In another aspect of the present invention, there is provided a system for controlling the speed of a vehicle, the system comprising:

[0042] A speed control system according to another aspect; and

[0043] A turn indicator is configured to output a turn indicator status signal indicating a condition of the turn indicator.

[0044] In another aspect of the invention, there is provided a vehicle comprising a speed control system of a previous aspect or a system of a previous aspect.

[0045] In one aspect of the present invention, there is provided a method for controlling the speed of a vehicle implemented by a speed control system, the method comprising causing the vehicle to operate according to a target speed, the method further comprising:

[0046] receiving a turn indicator status signal indicating a condition of a turn indicator of the vehicle;

[0047] determining a turn indicator target speed limit based on the turn indicator status signal; and

[0048] The vehicle is controlled according to the turn indicator target speed limit.

[0049] According to a further aspect of the present invention, there is provided a non-transitory computer-readable storage medium storing instructions which, when executed by one or more electronic processors, cause the one or more electronic processors to perform the method of the previous aspect.

[0050] In one aspect of the present invention, a method for controlling the speed of a vehicle implemented by a speed control system is provided, the method comprising:

[0051] causing the vehicle to operate according to a target speed; and

[0052] receiving a turn indicator status signal indicating a condition of a turn indicator of the vehicle,

[0053] The method includes limiting a vehicle speed based at least in part on the turn indicator status signal.

[0054] It is expressly intended that the various aspects, embodiments, examples and alternatives set forth in the preceding paragraphs, in the claims and / or in the following description and drawings, and in particular individual features thereof, may be employed independently or in any combination within the scope of the present application. That is, all embodiments and / or features of any embodiment may be combined in any manner and / or combination, unless such features are incompatible. Applicants reserve the right to change any originally filed claim or to file any new claim accordingly, including the right to amend any originally filed claim to be subordinate to any other claim and / or to incorporate any features of any other claim, even though protection was not originally claimed in this manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] One or more embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0056] Figure 1 shows a schematic representation of a vehicle having a speed control system according to an embodiment of the present invention;

[0057] Figure 2 shows a schematic representation of a steering wheel of a vehicle having a speed control system according to an embodiment of the invention;

[0058] Figure 3 shows a schematic representation of a speed control system according to an embodiment of the present invention;

[0059] Figure 4 Shown in Figure 1 A graph showing a vehicle speed VREF versus time in an example scenario encountered by a vehicle;

[0060] Figure 5 It is shown Figure 3 A flowchart of the operation of a maximum indicator setting speed calculation portion of a speed control system;

[0061] Figure 6 It is shown Figure 3 A flowchart of the operation of a maximum set speed calculation portion of a speed control system; and

[0062] Figure 7 is composed of a vehicle control unit or system (VCU) configured to implement Figure 3 A schematic diagram of an electronic controller of an embodiment of a speed control system. DETAILED DESCRIPTION

[0063] The contents of WO 2013 / 124321 are hereby incorporated by reference.

[0064] Figure 1 1 is a schematic diagram of a vehicle 10 according to an embodiment of the present invention. The vehicle 10 has a prime mover or motor 11 in the form of an internal combustion engine. The engine 11 is coupled to a transmission 12 by means of a coupling device 13. The coupling device 13 is arranged to allow the transmission 12 to gradually reach a speed compatible with the motor speed when the vehicle 10 accelerates from a standstill. The coupling device 13 is typically a friction clutch, a torque converter, etc. The transmission 12 is arranged to drive a pair of rear wheels 10RW and, in addition, optionally a pair of steerable front wheels 10FW. An accelerator pedal 1 allows the driver to control the amount of torque generated by the motor 11 under the control of a powertrain controller 17, while a brake pedal 2 allows the driver to apply the braking system under the control of a brake controller 16. A driving mode selector 19 is provided, by means of which the driver can select a road driving mode or one of a plurality of off-road driving modes, the plurality of off-road driving modes including a grass / gravel / snow (GGS) driving mode, a sand (S) driving mode, and a mud and rut (MR) driving mode. In some embodiments, the selector also allows selection of an "auto response mode" in which the vehicle 10 automatically determines the best driving mode at any given moment. The driving mode may be referred to as a "terrain response" (or "TR") mode.

[0065] The vehicle 10 has a vehicle control unit (VCU) 15 which is operable to implement a low speed vehicle speed control function or system. The low speed vehicle speed control function may also be referred to as an "off-road" or "off-highway" speed control function or system or an off-road or off-highway cruise control function or system. The low speed vehicle speed control function is operable if the vehicle speed VREF does not exceed a predetermined maximum speed. In the present embodiment, the predetermined maximum speed is 30 km / h. Above 30 km / h, the VCU 15 is operable to implement a higher speed control function or system. The VCU 15 may be described as implementing a low speed control system or a higher speed control system. Both the low speed control system and the higher speed control system functions are controlled by a user via input controls mounted to a steering wheel 171 of the vehicle 10. In Figure 2171 is shown in more detail in . It will be appreciated that a low speed vehicle speed control function or system may be useful when driving in off-highway driving conditions, while a higher speed control function or system may be useful when driving in on-highway driving conditions (e.g., on a relatively smooth, dry asphalt or concrete driving surface).

[0066] The input controls include a "set speed" control 173, actuation of which sets the value of the parameter driver_set_speed to be substantially equal to the current vehicle speed. Pressing the "+" (or "plus") button 174 allows the set speed to be increased, while pressing the "-" (or "minus") button 175 allows the set speed to be decreased. In some embodiments, if the speed control function is in an inactive state, the speed control function is activated when the "+" button 174 is pressed.

[0067] In the present embodiment, the VCU 15 is configured to implement an active speed control system (or "active cruise control") when the higher speed control system is operating. The active speed control system is configured to keep the vehicle 10 behind the leading vehicle at a predetermined distance in certain circumstances, as will be explained. The steering wheel 171 also has a pair of following distance control buttons 178, 179 for setting the value of the parameter distance_following, which is the distance that the driver expects the vehicle 10 to keep behind the leading vehicle. The VCU 15 is operable to control the vehicle 10 to keep a certain distance behind the leading vehicle, which is substantially equal to the distance represented by the parameter distance_following. The first button 178 of the buttons is operable to increase the value of the parameter distance_following, and thus increase the distance between the vehicle 10 and the leading vehicle, while the second button 179 of the buttons is operable to reduce the value of the parameter distance_following. The vehicle 10 has a radar module 5, which is mounted to the front of the vehicle and is arranged to project a radar beam in the front direction of the vehicle 10. The module 5 is arranged to detect radiation reflected by a leading vehicle and to determine the distance of the leading vehicle from the vehicle 10 (as the "host" vehicle). The module 5 is provided with a signal indicative of the current speed of the host vehicle 10. From this signal and data about the distance of the leading vehicle from the host vehicle 10 over time, the module 5 is able to calculate the speed of the leading vehicle. Other arrangements for determining the distance to the leading vehicle and the speed of the leading vehicle are also useful. In some embodiments, no active speed control functionality is provided and the following distance control buttons 178, 179 are omitted. In some embodiments, the radar module 5 is omitted.

[0068] Higher speed control systems are not the subject of the present application. Unless otherwise stated, the remainder of this specification relates to lower speed control systems.

[0069] When the low speed control system is activated, the VCU 15 controls the speed of the vehicle 10 according to a target speed value, which is set to be substantially equal to the set speed driver_set_speed selected by the driver or a lower value (if this is desired), as described in more detail below. The VCU 15 achieves this by calculating the maximum allowed speed max_set_speed of the vehicle 10 at a given moment. Unless a lower value is desired, the VCU 15 sets the value of max_set_speed to the value of the driver set speed driver_set_speed, as described in more detail below. The VCU 15 controls the speed of the vehicle 10 according to max_set_speed as the target speed value of the vehicle by making the vehicle speed VREF equal to the value of max_set_speed.

[0070] Then, the VCU 15 outputs the acceleration target value acc_tgt at a given time to the powertrain controller 30 (or control system) and the brake controller 16 (or control system) so as to keep the vehicle speed determined by the reference vehicle reference speed VREF at a desired value. If the driver overrides the speed control system and VREF exceeds 30 km / h, the speed control system suspends operation until VREF drops to 30 km / h or less. In some embodiments, the VCU 15 additionally or alternatively outputs the acceleration target value acc_tgt at a given time to different vehicle systems.

[0071] The driver can set the value of driver_set_speed of the low speed control system to the current vehicle speed VREF (assuming VREF does not exceed 30km / h) by pressing the "set speed" control 173 while the vehicle 10 is traveling. When the VCU 15 detects that the "set speed" control 173 is pressed, the VCU 15 takes a snapshot of the current speed VREF of the vehicle 10 and sets the value of driver_set_speed to correspond to the current speed. (It should be understood that if VREF exceeds 30km / h and the set speed control 173 is pressed, a higher speed control system is activated. In this embodiment, if the higher speed control system is activated because the value of driver_set_speed has been set to a value exceeding 30km / h, the low speed control system will not automatically reactivate once the speed drops below 30km / h.)

[0072] As described above, when the vehicle 10 is traveling along a road and the higher speed control system is active, i.e., VREF and driver_set_speed exceed the minimum allowed set speed set_speed_min (30 km / h in this embodiment), the VCU 15 is operable to allow the user to command the VCU 15 to maintain the current vehicle speed by pressing the set speed control 173. In the absence of traffic ahead of the vehicle 10 or other factors requiring a lower speed (see below), the VCU 15 controls the speed VREF of the vehicle 10 to maintain VREF substantially equal to the set speed value driver_set_speed.

[0073] In this embodiment, if the VCU 15 (by means of the radar module 5) detects the presence of a leading vehicle in front of the vehicle 10, the VCU 15 is operable to reduce the speed of the host vehicle 10 according to the speed of the leading vehicle so as to maintain a distance of not less than a prescribed distance behind the leading vehicle. The prescribed distance may be set by the driver by means of the "following distance" control buttons 178, 179 as described above. This function is only available when the higher speed control system is activated.

[0074] The vehicle 10 has a human-machine interface (HMI) in the form of a touch screen 18, by means of which the VCU 15 can communicate with the user. As described above, when the low-speed speed control system is in an activated state, the VCU 15 is operable to calculate the maximum permissible value max_set_speed of the set speed according to the terrain on which the vehicle is traveling. Therefore, the VCU 15 is operable to limit the maximum speed at which it will control the vehicle 10 to operate according to the terrain. Embodiments of the present invention allow for improved vehicle stability when operating under off-road conditions with reduced driver intervention. That is, since the VCU 15 determines the maximum permissible value max_set_speed of the set speed and limits the set speed accordingly, the driver does not need to intervene to reduce the value of the vehicle's set speed when the main terrain requires it, and to increase the set speed when the main terrain allows it.

[0075] Figure 3 The manner in which the value of max_set_speed is determined by the VCU 15 is shown. The VCU 15 comprises a "maximum set speed calculation" part (or "engine") 15a, a "maximum indicator set speed calculation" part (or "engine") 15b and a "vehicle acceleration calculation" part (or "engine") 15c.

[0076] Additionally, the input to the "maximum set speed calculation" portion (or "engine") 15a includes a "lateral acceleration limit calculation" portion 15d.

[0077] The "Vehicle Acceleration Calculation" section 15c is configured to calculate the desired acceleration rate of the vehicle 10 at a given moment based on received inputs, including inputs from the "Maximum Set Speed ​​Calculation" section 15a and the "Maximum Indicator Set Speed ​​Calculation" section 15b. The "Vehicle Acceleration Calculation" section 15c is configured to calculate the desired acceleration rate of the vehicle to maintain the value of the vehicle speed VREF equal to the value of max_set_speed received by the "Vehicle Acceleration Calculation" section 15c from the "Maximum Set Speed ​​Calculation" section 15a. Therefore, the VCU 15 controls the vehicle speed VREF according to the target speed value determined for max_set_speed.

[0078] The "maximum set speed calculation" portion 15a of the VCU 15 is configured to receive inputs corresponding to a plurality of vehicle parameters in addition to the current value of driver_set_speed. As described above, the "maximum set speed calculation" portion 15a outputs a value of max_set_speed that is no greater than the value of driver_set_speed, but may be lower if the "maximum set speed calculation" portion 15a determines that driving conditions require it, as described in more detail below. The parameters are: (a) a current vehicle surface friction coefficient reference value μmeas, which is a value calculated by the VCU 15 based on the value of one or more parameters (such as the amount of torque applied to the wheel that causes excessive wheel slip); (b) an expected surface friction coefficient value μTRmode corresponding to the currently selected vehicle driving mode, which is a prescribed value for each driving mode; (c) a current value of the steering angle "STEERING ANGLE, δ", which corresponds to the steerable wheel angle or steering wheel position; (d) a current yaw rate of the vehicle (which is determined by the output of a reference accelerometer) "YAW RATE"; (e) a current measured value of lateral acceleration "MEASURED LAT.ACC." (which is also determined by the output of a reference accelerometer); and (f) a current measured value of surface roughness "SURFACE ROUGHNESS" (which is determined by a reference suspension articulation). In some embodiments, the VCU 15 may also receive (g) a signal "GPSLOCATION" indicating the current location of the vehicle (determined by reference to the global satellite positioning system (GPS) output); and (h) information "CAMERA" obtained with the aid of a camera system. The information obtained with the aid of a camera system may include, for example, an alert in the event that it is determined that the vehicle 10 may be about to leave an off-road lane or track.

[0079] The "lateral acceleration limit calculation" section 15d of the VCU 15 is configured to determine the maximum permissible lateral acceleration rate max_lat_acc of the vehicle 10 during the driving process based on the surface friction coefficient reference value μmeas and the surface friction coefficient expected value μTRmode. The VCU 15 uses this max_lat_acc value to limit the value of max_set_speed when the vehicle is turning to prevent understeering.

[0080] In the present embodiment, the "maximum set speed calculation" portion 15a of the VCU 15 is also operable to calculate the radius of curvature of the path of the vehicle 10 on the terrain based on the steering angle. The VCU 15 compares this radius of curvature with the vehicle yaw rate and the measured lateral acceleration. If the VCU 15 detects that understeer is present, the VCU 15 is operable to reduce the value of max_set_speed accordingly. In some embodiments where a signal indicative of the current position of the vehicle is received, the VCU 15 may also take into account the path of travel of the vehicle as determined by the reference position signal to improve the reliability of the determination of the amount of understeer (if any) present.

[0081] In some embodiments, yaw rate and measured lateral acceleration are not used to determine the amount of understeer present. Other arrangements may also be used.

[0082] The "maximum set speed calculation" section 15a of the VCU 15 also determines the value of max_set_speed based on the value of the surface roughness of the terrain on which the vehicle 10 is driving. The value of max_set_speed may decrease as the surface roughness increases.

[0083] In this embodiment, the VCU 15 also receives the following signals:

[0084] (1) Indicates the turn signal indicator control 21 of the vehicle 10 ( Figure 1 )'s state or "condition" of the turn indicator status signal indicator_status;

[0085] (2) a signal TRmode indicating the driving mode (TRmode) in which the vehicle is currently operating; and

[0086] (3) A value of a comfort parameter “COMFORT” indicating a comfort level required by an occupant of the vehicle.

[0087] It should be understood that the turn indicator status signal indicator_status provides a left turn indicator status signal when the turn signal indicator control 21 is set to indicate a left turn, and provides a right turn indicator status signal when the turn signal indicator control 21 is set to indicate a right turn.

[0088] In the present embodiment, the signal TRmode is a signal indicative of the driver's selection of a terrain type by means of the driving mode selector 19. It may therefore be considered to provide a terrain indicator parameter which the VCU 15 may use to determine an appropriate speed for the vehicle 10 at a given moment.

[0089] In some embodiments, when the driving mode selector 19 is set to select the "automatic response mode" as described above, the terrain indicator parameter provided by the signal TRmode may be a signal indicating the preferred driving mode at any given moment determined automatically by the vehicle 10, rather than indicating the driver's selection of a terrain type.

[0090] The signal or input indicating the desired level of occupant comfort described in this embodiment is user-selectable and may therefore be referred to as a user-selectable input indicating the desired level of occupant comfort or the desired value of an occupant comfort parameter or comfort parameter or the desired occupant comfort level or comfort parameter value, or indicating the desired comfort level for an occupant of the vehicle.

[0091] The "maximum indicator set speed calculation" section 15b of the VCU 15 is configured to calculate the value of the maximum allowed vehicle speed indicator_set_speed based on the indicator_status signal and the TRmode signal. The value of indicator_set_speed can also be described as a turn indicator target speed limit. The value of indicator_set_speed is output to the "maximum set speed calculation" section 15a of the VCU 15, which takes into account the value of indicator_set_speed when determining the value of max_set_speed to be output to the "vehicle acceleration calculation" section 15c. In the present embodiment, the "maximum set speed calculation" section 15a limits the value of max_set_speed output therefrom so that it does not exceed the value of indicator_set_speed, as described below.

[0092] In the present embodiment, if the indicator_status signal indicates that the turn signal indicator control 21 is not activated, i.e., the turn signal indicator control 21 is in a neutral position, i.e., in a position where it does not signal a left turn or a right turn, the "maximum indicator set speed calculation" portion 15b of the VCU 15 is configured to output a value of indicator_set_speed corresponding to the maximum permissible value of the vehicle set speed when the low speed control system is in operation, which is 30 km / h in the present embodiment. This makes it so that when the turn signal indicator control 21 is in the neutral position, the "maximum indicator set speed calculation" portion 15b does not cause the speed of the vehicle 10 to decrease.

[0093] As described above, when the speed control system 15 is in an active state, i.e. the VCU 15 is controlling the vehicle speed according to the target speed value given by the value of max_set_speed, the "maximum indicator set speed calculation" part 15b of the VCU 15 is configured to calculate the value of the maximum allowed vehicle set speed indicator_set_speed at a given moment, i.e. the maximum allowed value of the vehicle speed based on the indicator_status signal and the TRmode signal.

[0094] In the present embodiment, the value of indicator_set_speed is independent of the comfort parameter value. However, in some alternative embodiments, the value of indicator_set_speed depends at least in part on the comfort parameter value. For higher values ​​of the comfort parameter value (which corresponds to a higher level of desired occupant comfort), the value of indicator_set_speed may be lower.

[0095] In this embodiment, when the vehicle 10 is operating in the Sand TR mode, the value of indicator_set_speed is higher, ie the reduction in vehicle speed when driving in the Sand mode is less severe. This is at least in part to ensure that the vehicle maintains forward motion when driving on sand.

[0096] In the present embodiment, for a given set of driving conditions, the value of indicator_set_speed is arranged to be highest in the sand mode and lowest in the grass gravel snow (GGS) TR mode. The other TR modes are in between, depending on the expected cornering speed of the surface. In the present embodiment, for a given set of inputs to the max_set_speed calculation section 15a, the value of indicator_set_speed is higher when the vehicle is operating in the road TR mode compared to mud and ruts, because it can be assumed that the customer can turn at a higher speed on an asphalt driving surface than on a mud driving surface.

[0097] In the present embodiment, the "maximum indicator set speed calculation" portion 15b of the VCU 15 also outputs a signal min_acc_rate to the "vehicle acceleration calculation" portion 15c. The value of min_acc_rate corresponds to the minimum allowable rate at which the vehicle decelerates from the current vehicle speed VREF based on the value of the comfort parameter and the TR mode in which the vehicle 10 is operating. It should be understood that in the present embodiment, the minimum allowable rate of deceleration is lower for higher desired comfort levels. It should be understood that the minimum allowable rate of deceleration is set so that the VCU 15 can control the time or distance over which the vehicle speed is reduced to a value that does not exceed the determined value of indicator_set_speed, thereby preventing the time or distance from becoming too large. Excessive time or distance may cause driver inconvenience caused by relatively slow progress over terrain.

[0098] It should be understood that when the indicator_status signal indicates that the turn signal indicator control 21 is activated, thereby signaling a left turn or a right turn, the value of indicator_set_speed becomes the value calculated by the "maximum indicator set speed calculation" section 15b based on the signal TRmode, rather than being set to output the value of indicator_set_speed corresponding to the maximum allowable value of the vehicle set speed when the low speed control system is operating as discussed above. Then, the max_set_speed calculation section 15a ensures that the value of max_set_speed does not exceed the value of indicator_set_speed. Therefore, if the value of max_set_speed calculated based on input other than the indicator_set_speed signal is greater than the value of indicator_set_speed, the value of max_set_speed is set to the value of indicator_set_speed, and the VCU 15 causes the vehicle to operate according to the new max_set_speed value, i.e., indicator_set_speed. Therefore, the vehicle speed VREF is made equal to the value of max_set_speed, which is equal to indicator_set_speed.

[0099] It should be appreciated that the VCU 15 continuously monitors the vehicle lateral acceleration and yaw rate, and determines when the vehicle 10 is turning based on the values ​​of the lateral acceleration and yaw rate. In some embodiments, the VCU 15 may also include the steering wheel angle as a factor when determining when the vehicle 10 is turning. It should be appreciated that the values ​​of the lateral acceleration, yaw rate, and steering wheel angle may provide information indicating that the vehicle may be turning, and may be considered a source of vehicle turning information.

[0100] The VCU 15 continues to calculate the value of max_set_speed based on the various inputs described above, and once a turn is initiated, the VCU 15 typically reduces the value of max_set_speed to below the value of indicator_set_speed. The reduction in max_set-speed may be more severe when driving on delicate surfaces such as grass or surfaces with a relatively low coefficient of friction.

[0101] When the indicator_status signal indicates that the turn signal indicator control 21 is in a position corresponding to signaling a left or right turn, and the value of max_set_speed decreases below the value of indicator_set_speed due to, for example, an increase in the value of lateral acceleration and / or yaw rate, the VCU 15 determines that a turn has been initiated. The VCU 15 then ignores the value of indicator_set_speed when determining the value of max_set_speed until the turn signal indicator control 21 is reset to the neutral position. This is to avoid inconvenience to the driver by maintaining a reduced vehicle speed in the event that the turn signal indicator control 21 cannot be cancelled after the turn is completed, i.e., because the turn signal indicator control 21 fails to resume the neutral position when the turn is completed.

[0102] Figure 4 The following situation is shown: before time t=t1, the vehicle 10 is traveling on the ground at a speed VREF=V1, with the turn signal indicator control 21 in the neutral position. The "maximum indicator set speed calculation" portion 15b of the VCU 15 is outputting a value of indicator_set_speed corresponding to the maximum allowed value when driving off-road (i.e., 30km / h). The VCU 15 causes the vehicle 10 to operate according to a set target speed, which, as described above, is equal to the value of max_set_speed calculated based on the input to the max_set_speed calculation portion 15a, and effectively ignores the signal indicator_set_speed. Therefore, the VCU 15 causes the vehicle speed VREF to be substantially equal to max_set_speed.

[0103] At time t1, the driver activates the turn signal indicator control 21 to indicate a left turn or a right turn. The "maximum indicator set speed calculation" portion 15b of the VCU 15 then calculates the value of the maximum allowed vehicle set speed indicator_set_speed at a given moment based on the TRmode signal. Figure 4 In the example shown, the value of indicator_set_speed is V2. The value of indicator_set_speed is output to the "maximum set speed calculation" portion 15a. The "maximum set speed calculation" portion 15a ensures that the output value of max_set_speed therefore does not exceed the value of indicator_set_speed.

[0104] As described above, the "maximum indicator set speed calculation" section 15b of the VCU 15 also calculates the value of min_acc_rate and outputs the value to the "vehicle acceleration calculation" section 15c. The "vehicle acceleration calculation" section 15c then causes the vehicle speed VREF to decrease from the current speed V1 to the value of max_set_speed, which in this example is limited to indicator_set_speed V2, at a rate not less than the value of min_acc_rate. It should be understood that in some cases, the value of max_set_speed may already be below the value of indicator_set_speed due to other input values ​​of the "maximum set speed calculation" section 15a, such as surface roughness, in which case the value of max_set_speed will not be set to the value of indicator_set_speed until the condition requiring max_set_speed to drop below indicator_set_speed is no longer met.

[0105] like Figure 4 As shown, during the period from time t1 to time t2, the vehicle speed VREF decreases to a value V2. From time t2 to time t3, the VCU 15 causes the vehicle 10 to operate according to a target speed set equal to the value of indicator_set_speed, i.e., the VCU 15 causes the vehicle speed VREF to be substantially equal to indicator_set_speed. At time t3, the vehicle 10 begins the intended turn, and the VCU 15 determines, by means of the "maximum set speed calculation" section 15a, that the vehicle speed should be limited to a value less than the current value of indicator_set_speed based on the value of the yaw rate and / or the measured lateral acceleration.

[0106] It should be understood that when the indicator_status signal indicates that the turn signal indicator control 21 is in a position corresponding to signaling a left or right turn, and the value of max_set_speed decreases below the value of indicator_set_speed due to the value of lateral acceleration and / or yaw rate, the VCU 15 determines that a turn has been initiated. Then, as described above, the VCU 15 ignores the value of indicator_set_speed when determining the value of max_set_speed until the turn signal indicator control 21 is reset to the neutral position. Figure 4 As shown, at time t3, the "maximum set speed calculation" section 15a outputs the value of max_set_speed to the "vehicle acceleration calculation" section 15c, which has dropped to the value V3, and the "vehicle acceleration calculation" section 15c drops the vehicle speed VREF to the value V3. Figure 4 , this is shown as occurring at time t4, at which time the appropriate speed V3 for the turn is reached.

[0107] Meanwhile, the "maximum indicator set speed calculation" portion 15b continues to output the value of indicator_set_speed calculated based on TRmode until the indicator_status signal indicates that the turn signal indicator control 21 is in the neutral position.

[0108] Figure 5 The operation of the "maximum indicator setting speed calculation" section 15b is shown in FIG.

[0109] At step 101, the "maximum indicator set speed calculation" portion 15b determines whether the signal indicator_status indicates that the turn signal indicator control 21 is in an activated state. If the signal indicator_status indicates that the turn signal indicator control 21 is in an inactive state, the method continues at step S103, otherwise the method proceeds to step S105.

[0110] At step S103, when the vehicle is operating off-road with the off-road speed control system activated, the "maximum indicator set speed calculation" portion 15b sets the value of indicator_set_speed to the maximum permissible value of the set speed, in this embodiment a value of 30 kph. The method then continues at step S101.

[0111] At step 105, the "maximum indicator set speed calculation" portion 15b calculates the value of indicator_set_speed based on the TRmode in which the vehicle is operating.

[0112] At step S107, the "maximum indicator set speed calculation" section 15b outputs the value of indicator_set_speed to the "maximum set speed calculation" section 15a.

[0113] At step S109, the "maximum indicator setting speed calculation" portion 15b calculates the value of min_acc_rate based on the TRmode the vehicle is operating in and the received value of the comfort parameter. For higher comfort parameter values, the value of min_acc_rate is lower to reduce occupant discomfort caused by vehicle 10 deceleration.

[0114] At step S111, the "maximum indicator setting speed calculation" portion 15b outputs the value of min_acc_rate to the "vehicle acceleration calculation" portion 15c.

[0115] Then, the method continues at step S101 .

[0116] Figure 6 The operation of the "maximum set speed calculation" portion 15a is shown in FIG.

[0117] At step S201, the "maximum set speed calculation" portion 15a determines the value of the maximum permitted vehicle speed max_set_speed under the control of the low speed control system, taking into account the input received as described above.

[0118] At step S203, the "maximum set speed calculation" part 15a determines whether the value of indicator_set_speed is lower than the value of max_set_speed calculated by reference to other inputs received. If the value of indicator_set_speed is not lower than the value of max_set_speed calculated by reference to other inputs received, the method continues at step S205, otherwise the method continues at step S207.

[0119] At step S205, the "maximum set speed calculation" portion 15a sets the value of max_set_speed thus outputted to the value of max_sed_speed calculated by reference to the input other than the received indicator_set_speed value. The method then continues at step S201.

[0120] At step S207, the "maximum set speed calculation" portion 15a sets the value of max_set_speed thus output as the value of indicator_set_speed. The method then continues at step S209.

[0121] At step S209, the "maximum set speed calculation" portion 15a determines whether the max_set_speed value calculated by reference to inputs other than the received indicator_set_speed value is less than the value of indicator_set_speed due to the vehicle turning. If this is the case, the method continues at step S211, otherwise step S207 is repeated.

[0122] At step S211, the "maximum set speed calculation" portion 15a sets the max_set_speed value thus outputted to the value of max_set_speed calculated by referring to the input other than the received indicator_set_speed value, and ignores the value of indicator_set_speed.

[0123] At step S213, the "maximum set speed calculation" part 15a checks the value of indicator_set_speed to check whether the value corresponds to the maximum allowed value of max_set_speed, thereby indicating that the indicator has been cancelled, i.e., the indicator is no longer active. If the value of indicator_set_speed does not correspond to the maximum allowed value, which indicates that the indicator has not been cancelled, the method continues at step S211, otherwise the method continues at step S201.

[0124] It should be understood that in some embodiments, at step S213, the "maximum set speed calculation" portion 15a may determine whether the indicator has been cancelled by referring to the signal indicator_status.

[0125] As described above, in some embodiments, the "maximum set speed calculation" portion 15a may be configured to receive one or both of the following: a signal indicating the current position of the vehicle (which is determined by reference to a global satellite positioning system (GPS) output); and information obtained by means of a camera system. By way of example, the information obtained by means of a camera system may include an alert if it is determined that the vehicle 10 may be about to leave an off-road lane or track.

[0126] In the case where the "maximum set speed calculation" portion 15a is configured to receive a signal indicating the current position of the vehicle (which is determined by reference to a global satellite positioning system (GPS) output), the "maximum set speed calculation" portion 15a can refer to map information in the form of map data corresponding to the current position of the vehicle 10, and predict the possible path of the vehicle ahead based on the map data, which map data can be referred to as the geographical location of one or more paths ahead of the vehicle. The "maximum set speed calculation" portion 15a can also take into account the indicator_status signal indicating the direction that the turn signal indicator control 21 has been set to indicate, i.e., indicating a left turn or a right turn ahead. Therefore, the VCU 15 can intelligently predict the route or path of the vehicle 10 based on the indicator_status signal and the map data, and therefore predict the severity of the turn that the vehicle may need to cross ahead. Therefore, the VCU can determine the predicted route or predicted path of the vehicle 10.

[0127] The value of this feature can be understood by considering the following situation: the first track that the vehicle 10 is following curves to the right, but there is a second track that branches off the first track to the left and needs to leave the first track. However, in some cases, leaving the first track to follow the second track may not require the vehicle 10 to change direction, but to move directly forward. The VCU 15 can determine that although the driver has chosen to activate the turn signal indicator control 21 to indicate a left turn ahead, there is no need to reduce speed because the predicted path requires little or no change of direction. However, alternatively, in some embodiments, the VCU 15 can trigger a speed reduction when the terrain is expected to change (which requires a speed reduction) when reaching the second track.

[0128] In some example scenarios, there may be a left turn and a right turn ahead, both of which require a change of direction, with the left turn being sharper than the right turn and requiring a more abrupt change of direction. Upon detecting that the driver has chosen to activate the turn signal indicator control 21 to indicate a left turn ahead, the "maximum indicator set speed calculation" portion 15b may set the value of indicator_set_speed to a lower value than if the driver had chosen to activate the turn signal indicator control 21 to indicate a right turn ahead, based on the more abrupt change of direction required for the predicted path.

[0129] It should be appreciated that other arrangements may be useful in some implementations.

[0130] Figure 7 is configured to implement Figure 3 Schematic diagram of an electronic controller 15' of a speed control system of an embodiment of the present invention.

[0131] It will be appreciated that various changes and modifications can be made to the present invention without departing from the scope of the present application.

Claims

1. A speed control system for a vehicle, the speed control system being configured to cause the vehicle to operate according to a target speed, the speed control system comprising one or more controllers, the speed control system being configured to: receiving a turn indicator status signal indicative of a condition of a turn signal indicator control of the vehicle; determining a turn indicator target speed limit based on the turn indicator status signal; and The vehicle is controlled according to the turn indicator target speed limit.

2. A speed control system according to claim 1, configured to receive a terrain indicator parameter indicative of a property of terrain on which the vehicle is travelling, wherein: The turn indicator target speed limit is determined based on the terrain indicator parameters.

3. The speed control system according to claim 2, wherein: The terrain indicator parameters are determined according to: a signal indicating the driver's selection of terrain type; or A signal indicative of terrain type generated by another vehicle system based on vehicle sensor information.

4. A speed control system according to any preceding claim, configured to receive an occupant comfort parameter indicative of a desired level of occupant comfort, and wherein: The turn indicator target speed limit is further determined based at least in part on the occupant comfort parameter.

5. A speed control system according to any preceding claim, configured to receive map information indicating the geographical location of one or more paths ahead of the vehicle, wherein: The turn indicator target speed limit is determined based on the map information.

6. The speed control system according to claim 5, configured to: determining a predicted route for the vehicle based on the map information and the turn indicator status signal; and The turn indicator target speed limit is determined based on the predicted route.

7. The speed control system according to claim 5, wherein: The turn indicator state signal comprises a left turn indicator state signal or a right turn indicator state signal, and the speed control system is configured to: determining a predicted route of the vehicle based on the map information and the left turn indicator state signal or the right turn indicator state signal; and The turn indicator target speed limit is determined based on the predicted route.

8. A speed control system according to any preceding claim, configured to: receiving vehicle turning information indicating that the vehicle is turning; and The vehicle speed is limited according to the vehicle turning information.

9. The speed control system according to claim 8, wherein: The vehicle turning information includes information indicating at least one of the following: The vehicle's lateral acceleration; and The yaw rate of the vehicle, The speed control system is configured to limit the vehicle speed based at least in part on one or both of the vehicle lateral acceleration and the yaw rate.

10. A speed control system according to any one of claims 8 or 9, configured to limit the vehicle speed based on the vehicle turning information, and to terminate limiting the vehicle speed to the turn indicator target speed limit when the vehicle turning information indicates that the vehicle speed should be reduced to a value equal to or less than the turn indicator target speed limit.

11. A speed control system according to claim 3 or any one of claims 4 to 10 as dependent on claim 3, configured wherein, when the speed control system terminates limiting the vehicle speed to the turn indicator target speed limit, the speed control system subsequently does not allow limiting the vehicle speed to the turn indicator target speed limit until the turn indicator status signal indicates that the condition of the turn indicator corresponds to neither a left turn nor a right turn.

12. A system for controlling the speed of a vehicle, the system comprising: A speed control system according to any preceding claim; as well as A turn signal indicator control is configured to output a turn indicator status signal indicating a condition of the turn signal indicator control.

13. A vehicle comprising a speed control system according to any one of claims 1 to 11 or a system according to claim 12.

14. A method of controlling the speed of a vehicle implemented by a speed control system, the method comprising causing the vehicle to operate according to a target speed, the method further comprising: receiving a turn indicator status signal indicating a condition of a turn indicator of the vehicle; determining a turn indicator target speed limit based on the turn indicator status signal; as well as The vehicle is controlled according to the turn indicator target speed limit.

15. A non-transitory computer-readable storage medium storing instructions which, when executed by one or more electronic processors, cause the one or more electronic processors to perform the method of claim 14.

Images