Turn assist control device

Abstract

To provide a turning assist control device capable of performing control intervention matched with the intention of a driver.SOLUTION: The turn assist control device includes a control unit 17. The control unit 17 detects a corner located in front of the vehicle 10 based on the detection information from the detection device 11 that detects the front of the vehicle 10, and controls any one or more of the driving force distribution of the front and rear wheels, the braking force distribution of the inner and outer wheels, and the driving force distribution in the vehicle 10 according to the distance from the vehicle 10 to the corner at the time when the operation information indicating the operation on the steering 12 is input.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a turn assist control system. [Background technology]

[0002] Patent Document 1 discloses a technology for obtaining map information and corner information from a camera, and controlling the steering amount and driving force to be appropriate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-147541 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned Patent Document 1, only map information and information from a camera are used, and the driver's steering operation is not reflected, so it is not possible to accurately determine whether control intervention is appropriate. For this reason, in the above-mentioned Patent Document 1, when the driver has a strong intention to control the vehicle, the control intervention may become a hindrance, and there is a risk that the control may not be optimal for each driver.

[0005] The present disclosure has been made in view of the above, and has an object to provide a turning assist control device that can intervene in control in accordance with the driver's intention. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the objectives, the turning assist control device of the present disclosure is a turning assist control device that assists in turning a vehicle and is equipped with a processor, wherein the processor detects a corner located in front of the vehicle based on detection information from a detection device that detects the front of the vehicle, and controls one or more of the distribution of driving force between the front and rear wheels of the vehicle, the distribution of braking force between the inner and outer wheels, and the distribution of driving force according to the distance from the vehicle to the corner at the time when operation information indicating an operation on the steering is input. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide an effect of enabling control intervention that matches the driver's intention. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram showing a functional configuration of a vehicle according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a flowchart showing an outline of processing executed by a control unit provided in a vehicle according to an embodiment of the present disclosure. [Figure 3] FIG. 3 is a diagram schematically showing the distance between a corner start point A (curve start point (R start point)) and the vehicle when the vehicle is traveling according to an embodiment of the present disclosure. [Figure 4] FIG. 4 is a diagram illustrating an outline of a determination method performed by a determination unit included in a vehicle according to an embodiment of the present disclosure. [Figure 5] FIG. 5 is a diagram illustrating an example of a distance discrimination map recorded by a distance discrimination map recording unit included in a vehicle according to an embodiment of the present disclosure. [Figure 6] FIG. 6 is a diagram illustrating an example of a front / rear distribution of driving force during cornering of a vehicle according to an embodiment of the present disclosure. [Figure 7] FIG. 7 is a diagram showing an example of braking and driving force distribution to inner and outer wheels during turning assistance while the vehicle is turning according to an embodiment of the present disclosure. [Figure 8]FIG. 8 is a diagram illustrating an example of turning assist control performed by a drive control unit included in a vehicle according to an embodiment of the present disclosure with respect to the distance from the vehicle to a corner start point A in a region β. DETAILED DESCRIPTION OF THE INVENTION

[0009] A vehicle equipped with a turning assist control device according to an embodiment of the present disclosure will be described below with reference to the drawings. Note that the components in the following embodiments include those that are easily replaceable by those skilled in the art, or those that are substantially identical. Furthermore, the drawings referred to in the following description merely show a schematic representation of the shape, size, and positional relationship to the extent that the contents of the present disclosure can be understood. In other words, the present disclosure is not limited to the shape, size, and positional relationship illustrated in each drawing.

[0010] [Vehicle functional configuration] Fig. 1 is a block diagram showing the functional configuration of a vehicle according to an embodiment of the present disclosure. Vehicle 10 shown in Fig. 1 is assumed to be, for example, a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), an electric vehicle (EV), or a fuel cell electric vehicle (FCEV). Vehicle 10 includes a detection device 11, a steering wheel 12, a detection device 13, a drive device 14, a recording unit 15, a display unit 16, and a control unit 17.

[0011] The detection device 11 is configured using a GPS (Global Positioning System) sensor, a camera, and the like. For example, the detection device 11 receives signals from multiple GPS satellites or transmitting antennas, calculates position information regarding the position (longitude and latitude) of the vehicle 10 based on the received signals, detects a corner start point located ahead of the vehicle 10 from the calculated position information, and outputs this detection result to the control unit 17. Here, the corner start point is a position where a straight road changes to a curve. Note that the detection device 11 detects the corner start point using a GPS sensor, but the corner start point may also be detected using multiple pieces of image data that are consecutive in time and captured continuously by a camera.

[0012] The detection device 13 detects the steering angle and operation speed according to the operation of the steering wheel 12 by the driver, and transmits the detection results to the control unit 17. The detection device 13 is configured using a steering sensor and the like.

[0013] The drive unit 14 is configured using drive wheels, an engine, a motor, an inverter, brakes, etc., and drives the vehicle 10 under the control of the control unit 17. The drive unit 14 is capable of increasing the yaw moment during turning, and performs, for example, distribution of drive force between the front and rear wheels of the vehicle 10 and distribution of drive force between the inner and outer wheels. Specifically, under the control of the control unit 17, the drive unit 14 drives in accordance with control signals input from the control unit 17 that control one or more of the distribution of drive force between the front and rear wheels of the vehicle 10, the distribution of braking force between the inner and outer wheels, and the distribution of drive force.

[0014] The recording unit 15 is configured using a recording medium such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The recording unit 15 has a program recording unit 151 that records various programs executed by the vehicle 10, and a distance discrimination map recording unit 152 for driving the turning assist control of the control unit 17. The distance discrimination map will be described in detail later.

[0015] The display unit 16 is configured using a liquid crystal display, an organic electroluminescent display (EL display), or the like, and displays various types of information under the control of the control unit 17.

[0016] The control unit 17 is realized using a processor having hardware such as an FPGA (Field-Programmable Gate Array) or a CPU (Central Processing Unit), and a memory that is a temporary storage area used by the processor and stores software (programs) capable of executing applications (hereinafter simply referred to as "apps"). The control unit 17 has a recognition unit 171, a detection unit 172, a determination unit 173, a calculation unit 174, and a drive control unit 175. In one embodiment, the control unit 17 functions as a turning assist control device.

[0017] The recognition unit 171 recognizes the corner start point A based on the detection result obtained by the detection device 11.

[0018] The detection unit 172 detects the start of a steering operation by the driver based on the detection result obtained by detecting the steering angle and operation speed according to the operation of the driver from the detection device 13.

[0019] The determination unit 173 determines whether the start of the steering operation detected by the detection unit 172 is an operation for cornering.

[0020] The calculation unit 174 calculates the distance between the steering operation start point detected by the detection unit 172 and the corner start point A recognized by the recognition unit 171.

[0021] The drive control unit 175 executes turning assist control to assist the turning of the drive unit 14, according to the distance calculated by the calculation unit 174. Specifically, the drive control unit 175 executes turning assist control to control one or more of the distribution of driving force between the front and rear wheels of the vehicle 10, the distribution of braking force between the inner and outer wheels, and the distribution of driving force, according to the distance from the vehicle 10 to the corner at the time when operation information indicating an operation on the steering wheel 12 is input.

[0022] [Processing of the control section] Next, a description will be given of the processing executed by the control unit 17. Fig. 2 is a flowchart showing an outline of the processing executed by the control unit 17.

[0023] As shown in Fig. 2, first, the recognition unit 171 recognizes a corner start point A based on the detection result detected by the detection device 11 (step S101). Fig. 3 is a diagram schematically showing the distance between the corner start point A (curve start point (R start point)) and the vehicle 10 while the vehicle 10 is traveling. As shown in Fig. 3, the recognition unit 171 recognizes the corner start point A based on the detection result detected by the detection device 11.

[0024] Next, the detection unit 172 detects the start of a steering operation by the driver based on the detection result of the detection device 13 detecting the steering angle and operation speed according to the operation by the driver (step S102).

[0025] The determination unit 173 determines whether the start of the steering operation detected by the detection unit 172 is an operation for cornering (step S103).

[0026] Fig. 4 is a diagram showing an outline of the determination method used by the determination unit 173. In Fig. 4(a) and (b), the horizontal axis represents distance. In Fig. 4(a), the vertical axis represents the steering angle, and in Fig. 4(b), the vertical axis represents the steering wheel operation speed. In Fig. 4(a) and (b), curves L1 and L11 represent changes in steering when the driver turns the corner toward corner start point A, and curves L2 to L4, L12, and L13 represent changes in steering when the driver avoids an obstacle or the like on the road.

[0027] The determination unit 173 determines whether the start of the steering operation detected by the detection unit 172 is an operation for cornering if the steering angle and the steering operation speed each satisfy the following conditions (1) and (2).

[0028] First, condition (1) will be described. In the case shown in Fig. 4(a), the determination unit 173 determines whether the steering angle input from the detection device 13 continues to increase over time and is equal to or less than threshold value X. If the steering angle continues to increase over time and is equal to or less than threshold value X (see curve L1), the determination unit 173 determines that the start of the steering operation is an operation for cornering. In contrast, if the steering angle does not continue to increase over time and is not equal to or less than threshold value X (see curves L2, L3, and L4), the determination unit 173 determines that the start of the steering operation is not an operation for cornering.

[0029] Next, condition (2) will be described. In the case shown in Fig. 4(b), the determination unit 173 determines whether the steering operation speed input from the detection device 13 increases continuously over time and is equal to or greater than threshold Y and equal to or less than threshold Z. If the steering operation speed increases continuously over time and is equal to or greater than threshold Y and equal to or less than threshold Z (see curve L11), the determination unit 173 determines that the start of the steering operation is an operation for cornering. If the steering operation speed does not increase continuously over time and is equal to or greater than threshold Y and equal to or less than threshold Z (see curves L12 and L13), the determination unit 173 determines that the start of the steering operation is not an operation for cornering.

[0030] In this way, the determination unit 173 determines whether the start of the steering operation detected by the detection unit 172 is an operation for cornering by using the steering angle and the steering operation speed, respectively, and determines whether the above conditions (1) and (2) are met. If conditions (1) and (condition) 2 are met, the determination unit 173 determines that the start of the steering operation is an operation for cornering, and excludes handle operations other than the target cornering operation. Note that the thresholds X to Z can be changed as appropriate depending on the distance between the vehicle 10 and the corner start point A and the speed of the vehicle 10.

[0031] Returning to FIG. 2 and step S103, the description will be continued. In step S103, if the determination unit 173 determines that the start of the steering operation detected by the detection unit 172 is an operation for cornering (step S103: Yes), the control unit 17 proceeds to step S104. On the other hand, if the determination unit 173 determines that the start of the steering operation detected by the detection unit 172 is not an operation for cornering (step S103: No), the control unit 17 ends this process.

[0032] In step S104, the calculation unit 174 calculates the distance between the steering operation start point and the corner start point A. Specifically, the calculation unit 174 calculates the distance between the corner start point A and the position information of the vehicle 10 detected by the detection device 11 at the steering operation start point.

[0033] Next, determination unit 173 determines whether the distance calculated by calculation unit 174 is within region α of the distance discrimination map recorded by distance discrimination map recording unit 152 (step S105). FIG. 5 is a diagram showing an example of a distance discrimination map recorded by distance discrimination map recording unit 152. In FIG. 5, the vertical axis represents distance. As shown in FIG. 5, determination unit 173 determines whether the distance calculated by calculation unit 174 is within region α of the distance discrimination map recorded by distance discrimination map recording unit 152. If determination unit 173 determines that the distance calculated by calculation unit 174 is within region α of the distance discrimination map recorded by distance discrimination map recording unit 152 (step S105: Yes), control unit 17 proceeds to step S114. On the other hand, if the judgment unit 173 determines that the distance calculated by the calculation unit 174 is not within the area α of the distance discrimination map recorded by the distance discrimination map recording unit 152 (step S105: No), the control unit 17 proceeds to step S106.

[0034] In step S106, determination unit 173 determines whether the distance calculated by calculation unit 174 is within region β of the distance discrimination map recorded by distance discrimination map recording unit 152. If determination unit 173 determines that the distance calculated by calculation unit 174 is within region β of the distance discrimination map recorded by distance discrimination map recording unit 152 (step S106: Yes), control unit 17 proceeds to step S112, which will be described later. On the other hand, if determination unit 173 determines that the distance calculated by calculation unit 174 is not within region β of the distance discrimination map recorded by distance discrimination map recording unit 152 (step S106: No), control unit 17 proceeds to step S107, which will be described later.

[0035] In step S107, determination unit 173 determines whether the distance calculated by calculation unit 174 is within region γ of the distance discrimination map recorded by distance discrimination map recording unit 152. If determination unit 173 determines that the distance calculated by calculation unit 174 is within region γ of the distance discrimination map recorded by distance discrimination map recording unit 152 (step S107: Yes), control unit 17 proceeds to step S113, which will be described later. On the other hand, if determination unit 173 determines that the distance calculated by calculation unit 174 is not within region γ of the distance discrimination map recorded by distance discrimination map recording unit 152 (step S107: No), control unit 17 determines that vehicle 10 is entering a corner (step S108), and proceeds to step S109.

[0036] In step S109, the determination unit 173 determines whether or not tire slip has occurred on the vehicle 10 based on the driving status of the drive unit 14. If the determination unit 173 determines that tire slip has occurred on the vehicle 10 (step S109: Yes), the control unit 17 proceeds to step S114. On the other hand, if the determination unit 173 determines that tire slip has not occurred on the vehicle 10 (step S109: No), the control unit 17 proceeds to step S110, which will be described later.

[0037] In step S110, the determination unit 173 determines whether the crosswind at the current position corresponding to the position information of the vehicle 10 detected by the detection device 11 is stronger than the threshold value. If the determination unit 173 determines that the crosswind at the current position corresponding to the position information of the vehicle 10 detected by the detection device 11 is stronger than the threshold value (step S110: Yes), the control unit 17 proceeds to step S114. On the other hand, if the determination unit 173 determines that the crosswind at the current position corresponding to the position information of the vehicle 10 detected by the detection device 11 is not stronger than the threshold value (step S110: No), the control unit 17 proceeds to step S111.

[0038] In step S111, the determination unit 173 determines whether or not the driver has performed an abrupt steering operation, based on the detection result of the steering operation of the steering wheel 12 detected by the detection device 13. If the determination unit 173 determines that the driver has performed an abrupt steering operation (step S111: Yes), the control unit 17 proceeds to step S114. On the other hand, if the determination unit 173 determines that the driver has not performed an abrupt steering operation (step S111: No), the control unit 17 ends this process.

[0039] In step S112, the drive control unit 175 executes turning assist control to assist the turning of the drive unit 14, in accordance with the distance calculated by the calculation unit 174. After step S112, the control unit 17 proceeds to step S108 described above.

[0040] Fig. 6 is a diagram showing an example of front / rear distribution of driving force while the vehicle 10 is turning. Fig. 7 is a diagram showing an example of braking and inner / outer wheel distribution of driving force while the vehicle 10 is turning with turn assist. In Fig. 6, the vertical axis indicates the driving force distribution rate to the rear wheels. Also, in Fig. 7, arrow A indicates the driving force, arrow B indicates the brake, and the length of each arrow indicates the magnitude of the force.

[0041] As shown in FIG. 6, in order to increase the yaw moment of the vehicle 10, the drive control unit 175 performs turning assist control on the drive unit 14 to increase the weight of the front wheels of the vehicle 10 when the vehicle 10 decelerates as it enters a corner, and to increase the weight of the rear wheels of the vehicle 10 when the vehicle 10 accelerates after entering the corner.

[0042] Also, as shown in FIG. 7, in the inner / outer wheel distribution of braking and driving force in the drive unit 14, the drive control unit 175 brakes the inner wheel side in the turning direction to decelerate it, and accelerates the outer wheel side to increase the driving force.

[0043] 8 is a diagram showing an example of turning assist control by the drive control unit 175 with respect to the distance from the vehicle 10 to the corner start point A in the region β. The horizontal axis represents time, Fig. 8(a) represents the amount of braking and driving force distribution between the inner and outer wheels (0 to 100%), and Fig. 8(b) represents the driving force distribution rate to the rear wheels.

[0044] As shown by curve L21 in Fig. 8(a), the drive control unit 175 does not perform turning assist control when there is a certain distance or more between the inner and outer wheel distribution of the braking and driving force of the drive unit 14, which directly affects the lateral behavior of the vehicle 10. Furthermore, as shown by curves L22 and L23 in Fig. 8(b), the drive control unit 175 gradually and smoothly changes the front / rear distribution of the driving force of the drive unit 14 according to the distance, and controls the distribution rate on the deceleration side, which has a greater influence in the lateral direction, so that the change becomes smaller until the distance approaches region γ.

[0045] In this way, the drive control unit 175 performs turning assist control by controlling one or more of the distribution of driving force between the front and rear wheels of the vehicle 10, the distribution of braking force between the inner and outer wheels, and the distribution of driving force.

[0046] Returning to FIG. 2, the description of step S113 and subsequent steps will be continued. In step S113, the drive control unit 175 executes turning assist control. Specifically, as shown in Figures 8(a) and 8(b), the drive control unit 175 executes turning assist control to reduce deceleration at the rear wheels of the vehicle 10. After step S113, the control unit 17 proceeds to step S108 described above.

[0047] In step S114, the drive control unit 175 stops the turning assist control. Specifically, for example, as shown by curve L3 in FIG. 4, if the driver suddenly performs a steering operation on the steering wheel 12 (step S111: Yes), the drive control unit 175 stops the turning assist control because the behavior of the vehicle 10 changes suddenly before and after the steering operation due to the intervention of the turning assist control. In addition, if the road on which the vehicle 10 is traveling has low μ due to ice or the like and the tires of the vehicle 10 slip (for example, step S109: Yes), or if a strong crosswind causes the vehicle 10 to sway sideways (step S110: Yes), the drive control unit 175 stops the turning assist control because the intervention of the turning assist control would result in excessive oversteer. After step S114, the control unit 17 ends this process.

[0048] According to the embodiment described above, the control unit 17 detects a corner located ahead of the vehicle 10 based on detection information from the detection device 11 that detects the area ahead of the vehicle 10, and controls one or more of the distribution of driving force between the front and rear wheels of the vehicle 10, the distribution of braking force between the inner and outer wheels, and the distribution of driving force depending on the distance from the vehicle 10 to the corner at the time when operation information indicating an operation on the steering wheel 12 is input, thereby enabling control intervention that matches the driver's intentions.

[0049] Further advantages and modifications will readily occur to those skilled in the art. The invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

[0050] Although some of the embodiments of the present application have been described in detail above with reference to the drawings, these are merely examples, and the present invention can be implemented in other forms that have undergone various modifications and improvements based on the knowledge of those skilled in the art, including the aspects described in the disclosure of the present invention. [Explanation of symbols]

[0051] 10 vehicles 11 Detection devices 12 Steering 13 Detection equipment 14 Drive unit 15 Recording section 16 Display 17 Control Unit 151 Program Recording Section 152 Distance discrimination map recording unit 171 Recognition part 172 Detection unit 173 Judgment section 174 Calculation Unit 175 Drive control unit

Claims

[Claim 1] A turning assist control device that assists a vehicle in turning, a processor; The processor: Detecting a corner located in front of the vehicle based on detection information from a detection device that detects a front of the vehicle; controlling at least one of a distribution of driving force between front and rear wheels of the vehicle, a distribution of braking force between inner and outer wheels, and a distribution of driving force in accordance with a distance from the vehicle to the corner at a time when operation information indicating an operation on the steering wheel is input; Turning assistance control device.

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