Vehicle speed control system and method

Abstract

Aspects of the present invention relate to a speed control system (15), method, and vehicle (10). The system causes the vehicle (10) to travel at a target speed value. The speed control system (15) receives a turn indicator status signal indicating the status of the vehicle's turn indicator control. The system (15) determines a turn indicator target speed limit in response to the turn indicator status signal and controls the vehicle in accordance with the turn indicator target speed limit.

Description

Technical Field

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

[0002] The content of WO2013 / 124321 is incorporated herein by reference.

Background Art

[0003] It is known to provide a speed control system for a vehicle, particularly a speed control system for operating a vehicle according to a target speed value. It is desirable to provide an improved speed control system for assisting a driver in overcoming terrain.

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to solve one or more drawbacks associated with the prior art.

Means for Solving the Problems

[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 for controlling the speed of a vehicle as set forth in the appended claims.

[0006] According to one aspect of the present invention, there is provided a system for controlling the speed of a vehicle, the speed control system being configured to operate the vehicle according to a target speed, the speed control system including one or more controllers, receiving a direction indicator status signal indicating a status of vehicle direction indicator control; determining a direction indicator target speed limit according to the direction indicator status signal; and controlling the vehicle according to the direction indicator target speed limit is configured as follows.

[0007] Embodiments of the present invention have the advantage of being able to reduce the stability of the vehicle and the driver's workload. This is at least partially because, when the left or right turn indicator is selected by automatically reducing the speed according to the state of the vehicle's direction indicator, the vehicle automatically reduces the speed before turning, so the applicant recognized that excessive braking just before turning can be avoided. By triggering a speed reduction according to the information of the direction indicator, the user's enjoyment may be improved.

[0008] Optionally, the speed control system is configured to receive a terrain indicator parameter indicating the nature of the terrain on which the vehicle is traveling, and the direction indicator target speed limit is determined according to the terrain indicator parameter.

[0009] The advantage of this function is that the speed can be reduced to a speed suitable for starting a direction change on the terrain on which the vehicle is traveling. In the case of a relatively slippery or brittle road surface such as grass, gravel, or snow, the direction indicator target speed limit may be lower than that of a non-slip or robust road surface such as tarmac or concrete.

[0010] Optionally, the terrain indicator parameter is a signal indicating the driver's selection of the terrain type; or a signal indicating the terrain type generated by another vehicle system according to the vehicle sensor information is determined accordingly.

[0011] A system that selects or automatically recognizes the type of terrain (or the nature of the terrain) does not form part of the present invention, but typically can distinguish surfaces such as rock, mud, sand, snow, etc., and can more appropriately adapt the vehicle system to the terrain on which the vehicle travels. A signal indicating the driver's selection of the type of terrain may be, for example, a signal indicating the driving mode in which the vehicle is operating, such as a terrain response (TR) mode. The TR mode may be, for example, a TR mode selected by the driver or automatically selected by the vehicle based on vehicle sensor information.

[0012] Optionally, the speed control system is configured to receive a passenger comfort parameter indicating a desired level of passenger comfort, and the turn indicator target speed limit is determined at least in part further in response to the passenger comfort parameter.

[0013] The advantage of this function is that the user satisfaction is improved because the vehicle speed gets closer to the passenger's expectation. In some embodiments, it should be understood that increasing the comfort level results in a decrease in the turn indicator target speed limit. However, this has the disadvantage of increasing the travel time. Therefore, the user can set the value of the desired comfort according to their preference.

[0014] Optionally, the speed control system is configured to receive map information indicating the geography of one or more routes ahead of the vehicle, and the turn indicator target speed limit is determined according to the map information.

[0015] Optionally, the speed control system determines the predicted route of the vehicle based on the map information and the turn indicator status signal; and determines the turn indicator target speed limit based on the predicted route is configured to be.

[0016] Optionally, the turn indicator status signal includes a left turn indicator status signal or a right turn indicator status signal, and the speed control system Determine a predicted route of a vehicle according to map information and a left turn indicator status signal or a right turn indicator status signal; and Determine a direction indicator target speed limit according to the predicted route It is configured as follows.

[0017] When there is a junction in front of the vehicle, it should be understood that the direction indicator status signal may help the speed control system predict the expected route of the vehicle when it reaches the junction. Therefore, the speed control system can set the direction indicator target speed limit to a value suitable for the predicted route of the vehicle when it reaches the junction.

[0018] Optionally, the speed control system is configured such that the sharper the turning angle predicted to occur on the predicted route, the lower the direction indicator target speed limit.

[0019] Optionally, the speed control system Receives vehicle turning information indicating that the vehicle is turning; and Limits the vehicle speed according to the vehicle turning information It is configured as follows.

[0020] It should be understood that the turning information means information regarding the turning of the vehicle around an axis substantially perpendicular to the vehicle, which is an axis perpendicular to the longitudinal and lateral axes of the vehicle.

[0021] Optionally, the vehicle turning information Vehicle lateral acceleration; and Information indicating at least one of the yaw rates of the vehicle Including The speed control system is configured to limit the vehicle speed at least partially depending on one or both of the vehicle lateral acceleration and the yaw rate.

[0022] It should be understood that the speed control system may be configured to limit the vehicle speed to the vehicle turning speed limit, at least partially, when the lateral acceleration or yaw rate exceeds their respective predetermined values. In addition to, or instead of, the lateral acceleration and / or yaw rate information, the vehicle turning information can include information indicating the position of the steering wheel, vehicle path information such as information indicating the radius of curvature of the vehicle path, or other appropriate information.

[0023] The turning speed limit of the vehicle is determined based at least in part on the lateral acceleration rate, and the turning speed limit value of the vehicle is lower for a higher value of the lateral acceleration rate compared to a lower value of the lateral acceleration rate.

[0024] The turning speed limit value of the vehicle is determined based at least in part on the yaw rate, and the turning speed limit value of the vehicle is lower when the value of the yaw rate is high than when the value of the yaw rate is low.

[0025] Optionally, the speed control system limits the vehicle speed according to the vehicle turning information, and when the vehicle turning information indicates that the vehicle speed should be reduced to a value below the direction indicator target speed limit, the speed control system is configured to terminate the limitation of the vehicle speed to the direction indicator target speed limit.

[0026] Optionally, when the speed control system terminates the limitation of the vehicle speed to the direction indicator target speed limit, the speed control system is configured not to permit subsequent limitation of the vehicle speed to the direction indicator target speed limit until the direction indicator status signal indicates that the status of the direction indicator does not correspond to either a left turn or a right turn.

[0027] In a further aspect of the present invention, A speed control system according to another aspect; and A direction indicator configured to output a direction indicator status signal indicating the status of the direction indicator A system for controlling the speed of a vehicle is provided.

[0028] In another aspect of the present invention, a vehicle is provided that includes the speed control system of the foregoing aspect or the system of the foregoing aspect.

[0029] In one aspect of the present invention, a method for controlling the speed of a vehicle executed by a speed control system is provided, the method including operating the vehicle according to a target speed, and further, receiving a direction indicator status signal indicating the status of a direction indicator of the vehicle; determining a direction indicator target speed limit according to the direction indicator status signal; and controlling the vehicle according to the direction indicator target speed limit is included.

[0030] In a further aspect of the present invention, a non-transitory computer-readable storage medium storing instructions that, when executed by one or more electronic processors, cause the one or more electronic processors to execute the method of the foregoing aspect is provided.

[0031] In one aspect of the present invention, a method for controlling the speed of a vehicle executed by a speed control system is provided, the method including operating the vehicle according to a target speed, and receiving a direction indicator status signal indicating the status of a direction indicator of the vehicle is included, the method including limiting the vehicle speed at least partially depending on the direction indicator status signal.

[0032] Within the scope of this application, it is explicitly intended that the various aspects, embodiments, examples, and alternatives described in the preceding paragraph, claims, and / or the following description and drawings, particularly their individual features, can be adopted independently or in any combination. That is, all embodiments and / or features of embodiments can be combined in any way and / or combination as long as such features are not incompatible. The applicant reserves the right to amend the originally filed claims or to file new claims accordingly. This includes the right to amend the originally filed claims to be dependent on the features of other claims or to incorporate the features of other claims, even if they were not originally claimed as such.

[0033] One or more embodiments of the present invention will be described by way of example only with reference to the accompanying drawings.

Brief Description of the Drawings

[0034]

Figure 1

Figure 2

Figure 3

Figure 4

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Figure 7

Best Mode for Carrying Out the Invention

[0035] The content of WO2013 / 124321 is incorporated herein by reference.

[0036] FIG. 1 is a schematic view 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 a coupling 13. The coupling 13 is arranged such that when the vehicle 10 is accelerated from a stationary state, the transmission 12 can gradually reach a speed compatible with the motor speed. The coupling 13 is typically a friction clutch, a torque converter, or the like. The transmission 12 is configured to drive a pair of rear wheels 10RW and optionally also a pair of steerable front wheels 10FW. By means of an accelerator pedal 1, the driver can control the amount of torque generated by the motor 11 under the control of a powertrain controller 17, and by means of a brake pedal 2, the driver can apply a braking system under the control of a brake controller 16. A driving mode selector 19 is provided, using which the driver can select one of a plurality of off-road driving modes including an on-road driving mode, or 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 enables the vehicle 10 to select an "automatic response mode" in which the vehicle automatically determines the optimal driving mode at any given time. The driving mode may be referred to as the "terrain response" (or "TR") mode.

[0037] Vehicle 10 is equipped with a vehicle control unit (VCU) 15 that is operable to execute a low-speed vehicle speed control function or system. The low-speed vehicle speed control function is also 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 when the vehicle speed VREF does not exceed a predetermined maximum speed. In this embodiment, the predetermined maximum speed is 30 km / h. When exceeding 30 km / h, the VCU 15 is operable to execute a higher-speed control function or system. The VCU 15 can be described as implementing a low-speed control system or a high-speed control system. The functions of both the low-speed control system and the high-speed control system are controlled by the user via an input control attached to the steering wheel 171 of the vehicle 10. The steering wheel 171 is shown in more detail in FIG. 2. It should be understood that the low-speed vehicle speed control function or system is useful during off-highway driving conditions, and the high-speed control function or system is useful during on-highway driving conditions such as on a relatively smooth and dry paved road surface or a concrete driving surface.

[0038] The input control includes a "set speed" control 173, and when this is actuated, the value of the parameter driver_set_speed is set to be approximately equal to the current vehicle speed. Pressing the "+" (or "plus") button 174 increases the set speed, and pressing the "-" (or "minus") button 175 decreases the set speed. In some embodiments, when the speed control function is not active when the "+" button 174 is pressed, the speed control function becomes active.

[0039] In this embodiment, the VCU 15 is configured to execute an active speed control system (or "active cruise control") when the high-speed speed control system is operating. The active speed control system is configured to maintain a predetermined distance behind a preceding vehicle for the vehicle 10 in certain situations, as will be described later. The wheel 171 also has a pair of following distance control buttons 178, 179 for setting the value of the parameter distance_following. This parameter is the distance that the driver wants to maintain the vehicle 10 behind the preceding vehicle. The VCU 15 can be operated to control the vehicle 10 to maintain a distance substantially equal to the distance represented by the parameter distance_following behind the preceding vehicle. The first button 178 can be operated to increase the value of the parameter distance_following, and thus increase the distance between the vehicle and the preceding vehicle, while the second button 179 can be operated to decrease the value of the parameter distance_following. The vehicle 10 has a radar module 5 attached to its front surface and configured to project a radar beam in the forward direction of the vehicle 10. The module 5 is configured to detect the radiation reflected by the preceding vehicle and determine the distance between the preceding vehicle and the vehicle 10 ("host" vehicle). A signal indicating the current speed of the host vehicle 10 is provided to the module 5. From this signal and data regarding the change in the distance from the host vehicle 10 to the leading vehicle as a function of time, the module 5 can calculate the speed of the leading vehicle. Other configurations for determining the distance from the leading vehicle and the speed of the leading vehicle are also useful. In some embodiments, the active speed control function is not provided and the subsequent following distance control buttons 178, 179 are omitted. In some embodiments, the radar module 5 is omitted.

[0040] The high-speed speed control system is not the subject of this application. The remainder of this specification relates to the low-speed speed control system unless otherwise specified.

[0041] When the low-speed speed control system is activated, the VCU 15 controls the speed of the vehicle 10 in accordance with the target speed value that is substantially equal to the set speed selected by the driver, driver_set_speed, or a lower value if desired as described in more detail below. The VCU 15 performs this by calculating the maximum allowable speed max_set_speed of the vehicle 10 at a particular point in time. The VCU 15 sets the value of max_set_speed to the value of the driver set speed driver_set_speed, except when a lower value is desired as described in more detail below. The VCU 15 controls the speed of the vehicle 10 in accordance with max_set_speed, which is the target speed value of the vehicle, by making the speed of the vehicle VREF equal to the value of max_set_speed.

[0042] Next, the VCU 15 outputs the target value of acceleration acc_tgt at a particular point in time to the power train controller 30 (or control system) and the brake controller 16 (or control system) so that the vehicle speed determined with reference to the vehicle reference speed VREF maintains the desired value. When the driver disables the speed control system and VREF exceeds 30 km / h, the speed control system stops operating until VREF is 30 km / h or less. In some embodiments, the VCU 15 outputs the target value of acceleration acc_tgt to another vehicle system additionally or alternatively.

[0043] The driver can set the value of driver_set_speed of the low-speed speed control system to the current vehicle speed VREF (on the condition that VREF does not exceed 30 km / h) by pressing the "Speed Setting" control 173 during the running of the vehicle 10. When the VCU 15 detects that the "Set Speed" control 173 has been pressed, it acquires 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 30 km / h and the set speed control 173 is pressed, a higher-speed speed control system will be activated. In this embodiment, since the value of driver_set_speed is set to a value exceeding 30 km / h, when the higher-speed speed control system is activated, the low-speed speed control system will not automatically restart even if the speed drops below 30 km / h.)

[0044] As described above, when the vehicle 10 is running along the road and the higher-speed speed control system is active, that is, when VREF and driver_set_speed exceed the minimum allowable set speed set_speed_min (30 km / h in this embodiment), the VCU 15 operates so that the user can instruct the VCU 15 to maintain the current vehicle speed by pressing the set speed control 173. When there is no traffic in front of the vehicle 10 or there are no other factors requiring low speed (see below), the VCU 15 controls the speed VREF of the vehicle 10 to maintain VREF approximately equal to the set speed value driver_set_speed.

[0045] In this embodiment, when the VCU 15 detects (by the radar module 5) that there is a preceding vehicle in front of the vehicle 10, the VCU 15 can operate to reduce the speed of the host vehicle 10 according to the speed of the preceding vehicle in order to maintain a distance greater than the specified distance behind the preceding vehicle. The specified distance can be set by the driver using the "Inter-vehicle Distance" control buttons 178, 179 as described above. This function can only be used when the higher-speed speed control system is active.

[0046] Vehicle 10 is equipped with a human-machine interface (HMI) in the form of a touch screen 18, through which the VCU 15 can communicate with the user. As described above, when the low-speed speed control system is active, the VCU 15 operates to calculate the maximum allowable value max_set_speed of the set speed according to the terrain on which the vehicle is traveling. Therefore, the VCU 15 can operate to limit the maximum speed for controlling the vehicle 10 according to the terrain. Embodiments of the present invention can reduce driver intervention and improve the stability of the vehicle when operating under off-highway conditions. That is, since the VCU 15 determines the maximum allowable value max_set_speed of the set speed and limits the set speed accordingly, the driver does not need to intervene to lower the value of the vehicle set speed when the terrain requires it, nor does the driver need to intervene to increase the set speed when the terrain permits.

[0047] Figure 3 shows how the VCU 15 determines the value of max_set_speed. The VCU 15 includes 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. Further, the input to the "maximum set speed calculation" part (or "engine") 15a includes a "lateral acceleration limit calculation" part 15d.

[0048] The "vehicle acceleration calculation" part 15c is configured to calculate the desired acceleration of the vehicle 10 at a specific point in time based on the received input including the input from the "maximum set speed calculation" part 15a and the "maximum indicator set speed calculation" part 15b. The "vehicle acceleration calculation" part 15c is configured to calculate the desired acceleration of the vehicle so as to maintain the value of the vehicle speed VREF equal to the value of max_set_speed received by the "vehicle acceleration calculation" part 15c from the "maximum set speed calculation" part 15a. Therefore, the VCU 15 controls the vehicle speed VREF according to the target speed value for determining max_set_speed.

[0049] The "maximum set speed calculation" part 15a of the VCU15 is configured to receive inputs corresponding to several vehicle parameters in addition to the current value of driver_set_speed. As described above, the "maximum set speed calculation" part 15a outputs a value of max_set_speed that is not greater than the value of driver_set_speed, but as will be described in more detail below, it may be smaller if the "maximum set speed calculation" part 15a determines that the driving conditions so require. The parameters are as follows: (a) The reference value of the current vehicle's surface friction coefficient, "μmeas", is a value calculated by the VCU15 based on the value of one or more parameters such as the amount of torque applied to a wheel that has induced excessive wheel slip; (b) The value of the predicted surface friction coefficient corresponding to the currently selected vehicle driving mode, "μTRmode", is a value defined for each driving mode; (c) The current value of the steering angle corresponds to the steerable road wheel angle, or, in some embodiments, corresponds to the position of the steering wheel, "steering angle, δ"; (d) The current yaw rate of the vehicle (determined with reference to the output of the accelerometer), "yaw rate"; (e) The current measured value of the lateral acceleration, "MEASURED LAT.ACC." (determined with reference to the output of the accelerometer); (f) The current measured value of the surface roughness, "SURFACE ROUGHNESS" (determined with reference to the articulation of the suspension). In some embodiments, the VCU15 may also receive (g) a signal indicating the current position of the vehicle, "GPS position" (determined with reference to the output of the Global Positioning System (GPS) or other global navigation satellite systems or other positioning systems), and / or (h) information obtained by a camera system, "camera". The information obtained by the camera system or image system may include, for example, warnings in the case where it is determined that the vehicle 10 may deviate from the off-road lane or the track.

[0050] The "Lateral Acceleration Limit Calculation" section 15d of the VCU 15 is configured to determine the maximum allowable lateral acceleration max_lat_acc of the vehicle 10 during travel from the reference value μmeas of the road surface friction coefficient and the expected value μTRmode of the road surface friction coefficient. The VCU 15 uses this value of max_lat_acc to limit the value of max_set_speed when the vehicle is cornering and prevent understeer.

[0051] In this embodiment, the "Maximum Set Speed Calculation" section 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 yaw rate and the measured lateral acceleration of the vehicle. When the VCU 15 detects the presence of understeer, the VCU 15 is operable to reduce the value of max_set_speed accordingly. In some embodiments where a signal indicating the current position of the vehicle is received, the VCU 15 can also consider the travel path of the vehicle determined with reference to the position signal and enhance the reliability of the determination of the amount of understeer present (if any).

[0052] In some embodiments, the yaw rate and the measured lateral acceleration are not used for determining the amount of understeer. Other configurations are also useful.

[0053] The "Maximum Set Speed Calculation" section 15a of the VCU 15 also determines the value of max_set_speed according to the value of the surface roughness of the terrain on which the vehicle 10 travels. When the surface roughness increases, the value of max_set_speed may decrease.

[0054] In this embodiment, the VCU 15 also receives the following signals: (1) A direction indicator status signal, indicator_status (FIG. 1), indicating the status or "state" of the direction indicator control 21 of the vehicle 10; (2) A signal TR mode indicating the driving mode (TR mode) in which the vehicle is currently operating; and The value of the comfort parameter "COMFORT" indicating the level of comfort required by the vehicle occupants.

[0055] The direction indicator status signal indicator_status should be understood to provide a left turn indicator status signal when the direction indicator control 21 is set to indicate a left turn, and to provide a right turn indicator status signal when the direction indicator control 21 is set to indicate a right turn.

[0056] In this embodiment, the signal TR mode is a signal indicating the driver's selection of the terrain type by the operation mode selector 19. Therefore, it is conceivable to provide a terrain indicator parameter that can be used when the VCU 15 determines the appropriate speed of the vehicle 10 at a given moment.

[0057] In some embodiments, the terrain indicator parameter provided by the signal TR mode may not indicate the driver's selection of the terrain type, but rather a signal indicating the priority operation mode at any given time automatically determined by the vehicle 10 when the operation mode selector 19 is set to select the "automatic response mode" as described above.

[0058] The signal or input indicating the desired level of occupant comfort described in this embodiment is selectable by the user, and thus may be referred to as a user-selectable input indicating the desired level of occupant comfort, the desired value of the occupant comfort parameter, the comfort parameter, or the desired level of comfort required by the vehicle occupants, the value of the comfort parameter, or the level of comfort.

[0059] The "Maximum Indicator Setting Speed Calculation" part 15b of the VCU15 is configured to calculate the value of the maximum allowable vehicle speed indicator_set_speed based on the indicator_status signal and the TRmode signal. The value of indicator_set_speed is also called the direction indicator target speed limit. The value of indicator_set_speed is output to the "Maximum Setting Speed Calculation" section 15a of the VCU15, and the VCU15 determines the value of max_set_speed output to the "Vehicle Acceleration Calculation" section 15c in consideration of the value of indicator_set_speed. In this embodiment, the "Maximum Setting Speed Calculation" section 15a restricts the value of max_set_speed output therefrom so that it does not exceed the value of indicator_set_speed as shown below.

[0060] In this embodiment, when the indicator_status signal indicates that the direction indicator control 21 is not operating, that is, when the direction indicator control 21 is in the neutral position where it emits neither a left turn nor a right turn signal, the "Maximum Indicator Setting Speed Calculation" part 15b of the VCU15 is configured to output a value of indicator_set_speed corresponding to the maximum allowable value of the vehicle setting speed (30 km / h in this embodiment) when the low-speed speed control system is operating. This is to prevent the "Maximum Indicator Setting Speed Calculation" part 15b from reducing the speed of the vehicle 10 when the direction indicator control 21 is in the neutral position.

[0061] As described above, the "Maximum Indicator Setting Speed Calculation" part 15b of the VCU15 is configured to calculate the value of the maximum allowable vehicle setting speed indicator_set_speed at a predetermined time point, that is, the maximum allowable value of the vehicle speed based on the indicator_status signal and the TRmode signal, when the speed control system 15 is active, that is, when the VCU15 controls the vehicle speed according to the value of the target speed specified by the value of max_set_speed.

[0062] In this embodiment, the value of indicator_set_speed is independent of the value of the comfort parameter value. However, in other embodiments, the value of indicator_set_speed is at least partially dependent on the comfort parameter value. The value of indicator_set_speed may be lower as the comfort parameter value is higher, which corresponds to a higher desirable level of passenger comfort.

[0063] In this embodiment, when the vehicle 10 is operating in the sand TR mode, the value of indicator_set_speed becomes higher, that is, the decrease in vehicle speed when driving in the sand mode is less. This is at least partially to ensure that the progress of the vehicle is maintained when driving on sand.

[0064] In this embodiment, for a given set of driving conditions, the value of indicator_set_speed is adjusted to be the highest in the sand mode and the lowest in the grass / gravel / snow (GGS) TR mode. Other TR modes are in between the two modes according to the expected turning speed on that road surface. In this embodiment, since it can be assumed that customers can turn at a higher speed on a paved road surface compared to a dirt road driving surface, for a given set of inputs to the max_set_speed calculation unit 15a, the value of indicator_set_speed when the vehicle is operating in the highway TR mode is higher than in the case of a dirt road or rut.

[0065] In this embodiment, the "maximum indicated set speed calculation" section 15b of the VCU 15 also outputs the signal min_acc_rate to the "vehicle acceleration calculation" section 15c. The value of min_acc_rate corresponds to the minimum allowable deceleration rate of the vehicle 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. In this embodiment, it should be understood that the higher the required comfort level, the lower the minimum allowable deceleration rate. The minimum allowable deceleration rate is set so that the VCU 15 controls the time or distance during which the vehicle speed is decelerated to a value not exceeding the determined value of indicator_set_speed, and the time or distance does not become excessively long. If the time or distance is too long, the progress on the terrain becomes relatively slow, which may cause inconvenience to the driver.

[0066] When the indicator status signal indicates that the direction indicator control 21 is activated to indicate a left turn or a right turn, the value of the indicator set speed is not set to output the value of the indicator set speed corresponding to the maximum allowable value of the vehicle set speed when the low-speed speed control system is operating as described above, but should be understood to be the value calculated by the "maximum indicator set speed calculation" section 15b based on the signal TR mode. Next, 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 an 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 operates the vehicle according to the new value of max_set_speed, 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.

[0067] It should be understood that the VCU15 continuously monitors the lateral acceleration and yaw rate of the vehicle and determines when the vehicle 10 is turning based on the values of the lateral acceleration and yaw rate. In some embodiments, the VCU15 can also include the angle of the steering wheel as an element when determining when the vehicle 10 is turning. The values of the lateral acceleration, yaw rate, and angle of the steering wheel can potentially provide information indicating that the vehicle may be turning and can be considered as sources of vehicle turning information.

[0068] The VCU15 continues to calculate the value of max_set_speed based on the various inputs described above, and the VCU15 typically reduces the value of max_set_speed below the value of indicator_set_speed when a turn is initiated. When driving on a fragile surface such as grass or a surface with a relatively low coefficient of friction, the reduction in max_set-speed can be more significant.

[0069] When the indicator_status signal indicates that the direction indicator control 21 is in a position indicating a left or right turn, and the value of max_set_speed falls below the value of indicator_set_speed, for example, due to an increase in the value of the lateral acceleration and / or yaw rate, the VCU15 determines that the direction change has been initiated. Thereafter, the VCU15 ignores the value of indicator_set_speed when determining the value of max_set_speed until the direction indicator control 21 is reset to the neutral position. This is to prevent the vehicle speed from remaining reduced and causing inconvenience to the driver in the event that the direction indicator control 21 cannot be cancelled after the turn is completed, i.e., when the direction indicator control 21 cannot return to the neutral position until the turn is completed.

[0070] Figure 4 shows a scenario where, before time t = t1, vehicle 10 is traveling on the ground at a speed VREF = V1 with the direction indicator control 21 in the neutral position. The "maximum indicator set speed calculation" part 15b of the VCU 15 outputs the value of indicator_set_speed corresponding to the maximum allowable value during off-road driving, i.e., 30 km / h. The VCU 15 operates vehicle 10 according to a target speed set equal to the value of max_set_speed calculated based on the input to the max_set_speed calculation unit 15a, and effectively ignores the signal indicator_set_speed as described above. Therefore, the VCU 15 makes the vehicle speed VREF substantially equal to max_set_speed.

[0071] At time t1, the driver activates the direction indicator control 21 to indicate a left or right turn. Next, the "maximum indicator set speed calculation" part 15b of the VCU 15 calculates the value of indicator_set_speed, the maximum allowable vehicle set speed at a specific point in time, based on the TRmode signal. In the example shown in Figure 4, the value of indicator_set_speed is V2. The value of indicator_set_speed is output to the "maximum set speed calculation" part 15a. The "maximum set speed calculation" part 15a thereby ensures that the value of the max_set_speed output does not exceed the value of indicator_set_speed.

[0072] In the "Maximum Indicator Setting Speed Calculation" section 15b of the VCU15, the value of min_acc_rate is also calculated and this value is output to the "Vehicle Acceleration Calculation" section 15c as described above. Next, the "Vehicle Acceleration Calculation" section 15c decreases the vehicle speed VREF from the current speed V1 to the value of max_set_speed at a speed greater than or equal to the value of min_acc_rate. In this example, max_set_speed is limited to V2 of indicator_set_speed. It should be understood that depending on the situation, due to other input values to the "Maximum Setting Speed Calculation" section 15a such as surface roughness, the value of max_set_speed may already be lower than the value of indicator_set_speed. In that case, the value of max_set_speed is not set to the value of indicator_set_speed until the condition requiring max_set_speed to be lower than indicator_set_speed is no longer satisfied.

[0073] As shown in FIG. 4, the vehicle speed VREF decreases to the value V2 over the period from time t1 to time t2. From time t2 to time t3, the VCU15 operates the vehicle 10 according to a target speed set equal to the value of indicator_set_speed. That is, the VCU15 makes the vehicle speed VREF substantially equal to indicator_set_speed. At time t3, the vehicle 10 starts a predicted turn, and the VCU15 determines that it is necessary to limit the vehicle speed to a value lower than the current value of indicator_set_speed based on the yaw rate and / or the measured lateral acceleration value by the "Maximum Setting Speed Calculation" section 15a.

[0074] The indicator status signal indicates that the direction indicator control 21 is in a position indicating a left or right turn. When the value of max_set_speed is lower than the value of indicator_set_speed based on the values of the lateral acceleration and / or yaw rate, it should be understood that the VCU 15 determines that the direction change has started. Thereafter, the VCU 15 ignores the value of indicator_set_speed when determining the value of max_set_speed until the direction indicator control 21 is reset to the neutral position as described above. As shown in FIG. 4, at time t3, the "maximum set speed calculation" section 15a outputs to the "vehicle acceleration calculation" section 15c the value of max_set_speed that decreases to the value V3, and the "vehicle acceleration calculation" section 15c decreases the vehicle speed VREF to the value V3. In FIG. 4, this is shown as occurring at time t4 when the speed V3 suitable for the turn is reached.

[0075] On the other hand, the "maximum indicator set speed calculation" section 15b continues to output the value of the indicator set speed calculated based on the TR mode until the indicator status signal indicates that the direction indicator control 21 is in the neutral position.

[0076] The operation of the "maximum indicator set speed calculation" section 15b is shown in FIG. 5.

[0077] In step 101, the "maximum indicator set speed calculation" section 15b determines whether the signal indicator status indicates that the direction indicator indicator control 21 is active. If the signal indicator status indicates that the direction indicator indicator control 21 is not active, the method proceeds to step S103; otherwise, the method proceeds to step S105.

[0078] In step S103, the "maximum indicator set speed calculation" part 15b sets the value of indicator_set_speed to the maximum allowable value of the set speed (30 kph in this embodiment) when the off-road speed control system is active and the vehicle is operating off-road. Thereafter, the method proceeds to step S101.

[0079] In step 105, the "maximum indicator set speed calculation" section 15b calculates the value of indicator_set_speed based on the TR mode in which the vehicle is operating.

[0080] In 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.

[0081] In step S109, the "maximum indicator set speed calculation" section 15b calculates the value of min_acc_rate based on the TR mode in which the vehicle is operating and the value of the received comfort parameter. In order to reduce the discomfort of the occupants due to the deceleration of the vehicle 10, the higher the value of the comfort parameter, the lower the value of min_acc_rate.

[0082] In step S111, the "maximum indicator set speed calculation" section 15b outputs the value of min_acc_rate to the "vehicle acceleration calculation" section 15c.

[0083] Next, the method proceeds to step S101.

[0084] The operation of the "maximum set speed calculation" part 15a is shown in FIG. 6.

[0085] In step S201, the "maximum set speed calculation" part 15a determines the value of max_set_speed, which is the maximum allowable vehicle speed when under the control of the low-speed speed control system, taking into account the input received as described above.

[0086] In 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 with reference to other received inputs. If the value of indicator_set_speed is not lower than the value of max_set_speed calculated with reference to other received inputs, the method proceeds to step S205; otherwise, the method continues to proceed to step S207.

[0087] In step S205, the "maximum set speed calculation" part 15a sets the value of max_set_speed output to the value of max_set_speed calculated with reference to inputs other than the received indicator_set_speed value. Then, the method proceeds to step S201.

[0088] In step S207, the "maximum set speed calculation" part 15a sets the value of max_set_speed output to the value of indicator_set_speed. Then, the method proceeds to step S209.

[0089] In step S209, the "maximum set speed calculation" part 15a determines whether the value of max_set_speed calculated with reference to inputs other than the received indicator_set_speed value is smaller than the value of indicator_set_speed due to the turning of the vehicle. If it is smaller, it proceeds to step S211; if it is not smaller, it repeats step S207.

[0090] In step S211, the "maximum set speed calculation" part 15a sets the value of max_set_speed calculated with reference to inputs other than the received indicator_set_speed value to the value of max_set_speed output thereby, and ignores the value of indicator_set_speed.

[0091] In step S213, the "maximum set speed calculation" part 15a checks the value of indicator_set_speed to check whether it corresponds to the maximum allowable value of max_set_speed. This indicates that the indicator has been canceled, that is, it is no longer active. If the value of indicator_set_speed does not correspond to the maximum allowable value, that is, if the indicator has not been canceled, the method proceeds to step S211, and otherwise, the method continues to proceed to step S201.

[0092] In some embodiments, it should be understood that in step S213, the "maximum set speed calculation" part 15a can determine whether the indicator has been canceled by referring to the signal indicator_status.

[0093] As described above, in some embodiments, the "maximum set speed calculation" part 15a may be configured to receive either or both of a signal indicating the current position of the vehicle (determined with reference to the output of a global positioning system (GPS)) and information acquired by the camera system. By way of example, the information acquired by the camera system may include a warning when it is determined that the vehicle 10 is about to deviate from the off-road lane or the track.

[0094] When the "maximum set speed calculation" unit 15a is configured to receive a signal indicating the current position of the vehicle (determined with reference to the output of the global positioning system (GPS)), the "maximum set speed calculation" unit 15a refers to map information in the form of map data corresponding to the current position of the vehicle 10, and can predict possible routes ahead of the vehicle based on the map data (which may refer to the terrain of one or more routes ahead of the vehicle). The "maximum set speed calculation" part 15a can also take into account the direction indicated by the indicator_status signal that the direction indicator control 21 is set to indicate a left turn or a right turn. 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 thus the intensity of the turns that the vehicle may need to pass through ahead. Therefore, the VCU can determine the predicted route or path of the vehicle 10.

[0095] The value of this function can be understood by considering a situation where the first truck that the vehicle 10 is following is turning right, but there is a second truck branching off from the first truck, so the vehicle needs to deviate to the left from the first truck. However, when leaving the first truck and following the second truck, the vehicle 10 may not need to change direction and may only need to move straight ahead. Even if the driver selects to activate the direction indicator control 21 to indicate a left turn ahead, the VCU 15 may determine that there is little or no need to reduce the speed because there is little or no need to change direction on the predicted route. Alternatively, in some embodiments, the VCU 15 may still predict the possibility of terrain changes when reaching the second truck and trigger a speed reduction, and a speed reduction may be required.

[0096] In some scenario examples, there are left and right turns ahead, both of which require a change in direction, but the left turn is sharper than the right turn and a sharper change in direction is required. When it is detected that the driver has selected to activate the direction indicator control 21 to indicate a left turn, the "maximum indicator setting speed calculation" part 15b can set the value of indicator_set_speed to a lower value based on the sharper change in direction required for the predicted route than when the driver has selected to activate the direction indicator control 21 to indicate a right turn.

[0097] In some embodiments, it should be understood that other arrangements may be useful.

[0098] FIG. 7 is a schematic diagram of an electronic control unit 15' configured to implement the speed control system of the embodiment of FIG. 3.

[0099] It is understood that various changes and modifications can be made to the present invention without departing from the scope of the present invention.

Claims

1. A vehicle speed control system configured to operate a vehicle according to a target speed and including one or more controllers, receiving a direction indicator status signal indicating a status of direction indicator control of the vehicle; determining a direction indicator target speed limit according to the direction indicator status signal; and controlling the vehicle according to the direction indicator target speed limit A speed control system configured as described above.

2. The speed control system according to claim 1, configured to receive a terrain indicator parameter indicating a nature of terrain on which the vehicle is traveling, and the direction indicator target speed limit is configured to be determined according to the terrain indicator parameter.

3. The terrain indicator parameter is a signal indicating a driver's selection of a terrain type; or a signal indicating a terrain type generated by another vehicle system according to vehicle sensor information The speed control system according to claim 2, determined according to the above.

4. The speed control system according to any one of claims 1 to 3, configured to receive a passenger comfort parameter indicating a desired level of passenger comfort, and the direction indicator target speed limit is configured to be determined at least partially further according to the passenger comfort parameter.

5. The speed control system according to any one of claims 1 to 4, configured to receive map information indicating a terrain of one or more routes in front of the vehicle, and the direction indicator target speed limit is configured to be determined according to the map information.

6. determining a predicted route of the vehicle according to the map information and the direction indicator status signal; and determining the direction indicator target speed limit according to the predicted route The speed control system according to claim 5, configured as described above.

7. The direction indicator status signal includes a left direction indicator status signal or a right direction indicator status signal, and the speed control system determines 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 determines the direction indicator target speed limit based on the predicted route The speed control system according to claim 5, configured as described above.

8. receiving vehicle turning information indicating that the vehicle is turning; and Limit the vehicle speed according to the vehicle turning information The speed control system according to any one of claims 1 to 7, which is configured to

9. The vehicle turning information includes Vehicle lateral acceleration; and Yaw rate of the vehicle including information indicating at least one of, The speed control system is configured to limit the vehicle speed at least partially depending on one or both of the vehicle lateral acceleration and the yaw rate. The speed control system according to claim 8.

10. Limit the vehicle speed according to the vehicle turning information, and when the vehicle turning information indicates that the vehicle speed should be reduced below the direction indicator target speed limit value, end limiting the vehicle speed to the direction indicator target speed limit value. The speed control system according to claim 8 or 9, which is configured to

11. When the speed control system finishes limiting the vehicle speed to the direction indicator target speed limit, the speed control system does not permit limiting the vehicle speed to the direction indicator target speed limit thereafter until the direction indicator state signal indicates that the state of the direction indicator does not correspond to either a left turn or a right turn. The speed control system according to any one of claims 3 or claims 4 to 10 dependent on claim 3.

12. The speed control system according to any one of claims 1 to 11; and A direction indicator control configured to output a direction indicator state signal indicating the state of the direction indicator control A system for controlling the speed of a vehicle, including

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

14. A method for controlling the speed of a vehicle executed by a speed control system, including operating the vehicle according to a target speed, the method further comprising Receiving a direction indicator state signal indicating the state of the direction indicator control of the vehicle; Determining a direction indicator target speed limit according to the direction indicator state signal; and Controlling the vehicle according to the direction indicator target speed limit including, method.

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

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