JP2017065486A - Control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an energy consumption amount in turning assistance of a vehicle while suppressing discomfort for steering operation.SOLUTION: There is provided with a control device for a vehicle comprising: a power steering adjustment section adjusting an assist amount of a steering by a power steering mechanism based on third state quantity calculated by comparing first state quantity related to a shape of a traveling road of the vehicle and second state quantity related to a traveling state of the vehicle; and a steering stability control section adjusting a control amount for controlling a driving power distribution of left and right wheels based on the third state quantity. In the control device for the vehicle, when the third state quantity is greater than a predetermined value, the steering stability control section adjusts the control amount such that the larger an amount of the assist amount adjusted by the power steering adjustment section is, the smaller the control amount is while the power steering adjustment section is adjusting the assist amount such that the assist amount becomes larger in comparison with a reference assist amount obtained on the basis of steering input of a driver.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a vehicle control device.

  2. Description of the Related Art In recent years, a technique for generating a yaw moment by controlling the driving force distribution of left and right wheels according to the traveling state of a vehicle is known. Further, a technique for assisting a driver's turning by a power steering mechanism in accordance with a traveling state of the vehicle is known.

  For example, in Patent Document 1, in order to improve the turning performance and the steering feeling, it is overbased on the deviation between the standard yaw rate preset according to the steering angle and the vehicle speed and the actual yaw rate detected by the yaw rate sensor. In the electric power steering device that detects the steer state and controls the assist motor to suppress oversteer, the left and right driving force distribution device that controls the yaw moment of the vehicle by controlling the driving force distribution of the left and right wheels A technique is disclosed in which the control gain calculation unit reduces the control gain for oversteer suppression when the amount of distribution to the wheels is increased.

JP 2010-58688 A

  A yaw moment can be generated by generating a driving force difference between the left and right wheels by controlling the driving force distribution between the left and right wheels. Thereby, turning of the vehicle can be supported. However, when it is attempted to achieve an equivalent turning amount by only assisting turning of the vehicle by controlling the driving force distribution of the left and right wheels, compared with the case of assisting turning of the vehicle by assisting the turning of the driver by the power steering mechanism. Thus, more energy is consumed in the control.

  On the other hand, in the driver steering assist by the power steering mechanism, the driver's load in the steering can vary depending on the control amount, so the vehicle turning support is realized only by the driver steering assist by the power steering mechanism. Attempting to do so may cause a sense of incongruity in steering.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to reduce the amount of energy consumed in turning support of a vehicle while suppressing a sense of incongruity with respect to steering. Another object of the present invention is to provide a new and improved vehicle control apparatus.

  In order to solve the above-described problem, according to one aspect of the present invention, a first state quantity related to the shape of a traveling path of a vehicle is compared with a second state quantity related to the traveling state of the vehicle. Based on the calculated third state quantity, a power steering adjustment unit for adjusting the steering assist amount by the power steering mechanism, and for controlling the driving force distribution of the left and right wheels based on the third state quantity And a steering control unit that adjusts the control amount of the vehicle. When the third state amount is greater than a predetermined value, the power steering adjustment unit is obtained based on the steering input of the driver. The assist amount is adjusted to be larger than a reference assist amount to be obtained, and the steering control unit has a larger amount of the assist amount adjusted by the power steering adjustment unit. Etc., the control apparatus for a vehicle and adjusting the control amount so as to decrease is provided.

  The power steering adjustment unit adjusts the assist amount so as to increase as the third state amount increases when the third state amount is larger than the predetermined value, and the steering control unit The control amount may be adjusted such that when the third state quantity is larger than the predetermined value, the control quantity is decreased as the third state quantity increases.

  The power steering adjustment unit adjusts the assist amount so as to increase as the third state amount increases when the third state amount is larger than the predetermined value, and the steering control unit The control amount may be adjusted such that when the third state quantity is larger than the predetermined value, the control quantity is decreased as the third state quantity increases.

  The first state quantity is a first reference yaw rate obtained from the curvature of the traveling path and the vehicle speed, and the second state quantity is a second reference yaw rate obtained from a steering steering amount and the vehicle speed. The third state quantity may be a difference between the first reference yaw rate and the second reference yaw rate.

  The first state quantity is a value indicating a direction of a point ahead on the traveling path with respect to a current position of the center of the vehicle, and the second state quantity is a value indicating a direction in which the vehicle body of the vehicle is currently facing. The third state quantity may be calculated based on an angle formed by the direction of a point ahead of the current position at the center of the vehicle by a predetermined distance on the traveling path and the direction in which the vehicle body of the vehicle is currently facing. Good.

  The first state quantity is a value indicating a position of a forward point on the traveling path, and the second state quantity is a value indicating a position of a point on the direction in which the vehicle body of the vehicle is currently facing, The third state quantity may be calculated based on a lateral deviation of the vehicle between a point ahead on the traveling path and a point on the direction in which the vehicle body currently faces.

  The steering control unit includes a control target yaw rate calculation unit that calculates the control target yaw rate from a vehicle model that defines a relationship between the control target yaw rate of the vehicle, the vehicle speed, and the steering amount, and is generated in the vehicle. A feedback yaw rate calculation unit for calculating a feedback yaw rate for comparison with the control target yaw rate, and a control target moment as the control amount based on a comparison result between the control target yaw rate and the feedback yaw rate. The control target moment calculation unit adds a steady target damping moment and a transient target inertia compensation moment that are calculated based on the comparison result, respectively. The moment is calculated and the third state Based on the amount of transition, it may adjust the target inertia compensating moment.

  The feedback yaw rate calculation unit obtains the second reference yaw rate and the actual yaw rate detected from the yaw rate sensor, and the comparison value calculated by comparing the second reference yaw rate and the actual yaw rate is small. The feedback yaw rate may be calculated from the second reference yaw rate and the actual yaw rate by increasing the distribution of the second reference yaw rate and increasing the distribution of the actual yaw rate when the comparison value is large.

  As described above, according to the present invention, while suppressing the uncomfortable feeling associated with the intervention of the steering assist control, a predetermined turning amount associated with the steering of the driver is ensured, and the energy consumption in the turning assistance of the vehicle is reduced. It becomes possible to reduce.

1 is a schematic diagram illustrating an example of a schematic configuration of a vehicle according to an embodiment of the present invention. It is a mimetic diagram for explaining support of turning of vehicles by a control device concerning the embodiment. It is explanatory drawing which shows an example of a function structure of the control apparatus which concerns on the same embodiment. It is explanatory drawing which shows an example of the map showing the relationship between the difference ((gamma) _diff) of a 2nd reference | standard yaw rate and an actual yaw rate, and weighting gain ((kappa)). It is explanatory drawing which shows an example of the map showing the relationship between the differential value of the difference (Δγ_Std) between the first reference yaw rate and the second reference yaw rate and the counter change amount (ΔCnt). It is explanatory drawing which shows an example of the map showing the relationship between the differential value (DELTA (gamma) _Std) of a 1st reference | standard yaw rate and a 2nd reference | standard yaw rate, and an inertia compensation moment correction gain (TransAdjustGain). It is explanatory drawing which shows an example of the map showing the relationship between the difference ((DELTA) gamma_Std) of a 1st reference | standard yaw rate and a 2nd reference | standard yaw rate, and a steering assist raising request value (RequestForStearingAssist). It is explanatory drawing which shows an example of the map showing the relationship between the difference (Δγ_Std) between the first reference yaw rate and the second reference yaw rate and the damping moment correction gain (DampAdjustGain). It is a flowchart which shows an example of the flow of the process which the control apparatus which concerns on the same embodiment performs. It is a schematic diagram which shows each setting value of a steering angle and vehicle speed. It is a schematic diagram which shows the test result about each of the relationship between a steering angle and the yaw rate which generate | occur | produces in a vehicle, and each transition of the moving amount | distance to a horizontal direction. It is a schematic diagram which shows the test result about each of the transition of the absolute value of the relationship between the yaw rate which generate | occur | produces in a vehicle, and a motor request torque total amount, and a motor request torque total amount. It is a schematic diagram which shows the test result about transition of power consumption. It is a schematic diagram which shows each setting value of a steering angle and vehicle speed. It is a schematic diagram which shows the test result about each of the relationship between a steering angle and the yaw rate which generate | occur | produces in a vehicle, and each transition of the moving amount | distance to a horizontal direction. It is a schematic diagram which shows the test result about the transition of the absolute value of the fluctuation component of steering of the steering of the motor required torque total amount and the transition of the target inertia compensation moment (MgTransTgt). It is a schematic diagram which shows the test result about transition of power consumption.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

<1. Vehicle configuration>
First, an overall configuration of a vehicle 1000 according to the present embodiment will be described with reference to FIG. FIG. 1 is a schematic diagram illustrating an example of a schematic configuration of a vehicle 1000 according to the present embodiment. As shown in FIG. 1, a vehicle 1000 includes front wheels 100, 102, rear wheels 104, 106, motors 108, 110, 112, 114 that drive the front wheels 100, 102 and rear wheels 104, 106, and front wheels. Wheel speed sensors 116, 118, 120, 122 for detecting wheel speeds of 100, 102 and rear wheels 104, 106, a steering wheel 124, a steering angle sensor 130, a power steering mechanism 140, and a yaw rate sensor 150, , An acceleration sensor 160, an external recognition unit 170, and a control device 200.

  The vehicle 1000 according to the present embodiment is provided with motors 108, 110, 112, and 114 for driving the front wheels 100 and 102 and the rear wheels 104 and 106, respectively. For this reason, it is possible to individually control the driving torque for each of the front wheels 100 and 102 and the rear wheels 104 and 106. Therefore, the yaw moment can be generated by controlling the driving force distribution of the left and right wheels of the front wheels 100 and 102 or the rear wheels 104 and 106. In the present embodiment, the yaw moment is generated by individually controlling the driving torque of the left and right wheels of the rear wheels 104 and 106 and generating a driving force difference. Based on the operation instruction of the control device 200, the motors 112 and 114 corresponding to the rear wheels 104 and 106 are driven to control the driving torque of the left and right wheels of the rear wheels 104 and 106. Thereby, the control device 200 controls the driving force distribution of the left and right wheels of the rear wheels 104 and 106.

  The yaw moment may be generated by controlling the driving force distribution of the left and right wheels of the front wheels 100 and 102. Further, the yaw moment may be generated by controlling the driving force distribution of the left and right wheels for both the front wheels 100 and 102 and the rear wheels 104 and 106, respectively. In addition, from the configuration of the vehicle 1000 according to the present embodiment, one of the motors 108 and 110 that drive the front wheels 100 and 102 or the motors 112 and 114 that drive the rear wheels 104 and 106 may be omitted.

  The power steering mechanism 140 assists the driver's steering via the steering wheel 124. The power steering mechanism 140 assists in turning based on a reference assist amount calculated by a power steering control device (not shown). The reference assist amount is calculated according to the driver's steering input such as steering steering torque or steering rotation speed. For example, a larger value is calculated as the reference assist amount as the steering torque by the driver is larger. The steering steering torque by the driver is detected by a torque sensor provided in the power steering mechanism 140. The driver's steering assist by the power steering mechanism 140 is realized by driving an electric motor, for example. In the present embodiment, the control device 200 adjusts the steering assist amount by the power steering mechanism 140. Thereby, the turning support of the vehicle 1000 is realized.

  The steering angle sensor 130 detects the steering angle θh corresponding to the operation of the steering wheel 124 by the driver. The yaw rate sensor 150 detects the actual yaw rate γ of the vehicle 1000. Wheel speed sensors 116, 118, 120 and 122 detect vehicle speed V of vehicle 1000. The acceleration sensor 160 detects the acceleration of the vehicle 1000.

  The external recognition unit 170 includes a pair of left and right cameras having image sensors such as a CCD sensor and a CMOS sensor. The external recognition unit 170 captures an external environment outside the vehicle and indicates the shape of a traveling path on which the host vehicle travels. Can be recognized as image information. Information indicating the shape of the traveling path of the vehicle 1000 acquired by the external recognition unit 170 is used for calculation by the control device 200. In addition, when using information indicating the shape of a traveling path on which the host vehicle travels included in information acquired from the outside such as navigation information, the external recognition unit 170 may be omitted from the configuration of the vehicle 1000.

  The control device 200 includes a CPU (Central Processing Unit) that is an arithmetic processing device, a ROM (Read Only Memory) that stores programs used by the CPU, calculation parameters, and the like, a program used in the execution of the CPU, and changes as appropriate in the execution of the CPU. RAM (Random Access Memory) that temporarily stores parameters to be stored.

  Control device 200 controls the operation of each device constituting vehicle 1000. Specifically, the control device 200 issues an operation instruction to each actuator to be controlled using an electrical signal. More specifically, the control device 200 controls driving of the motors 112 and 114 corresponding to the rear wheels 104 and 106. Thereby, the control device 200 controls the driving force distribution of the left and right wheels of the rear wheels 104 and 106. Further, the control device 200 adjusts the steering assist amount by the power steering mechanism 140. In the present embodiment, turning control of the vehicle 1000 is realized by the control of the driving force distribution of the left and right wheels of the rear wheels 104 and 106 by the control device 200 and the adjustment of the steering assist amount by the power steering mechanism 140. .

  FIG. 2 is a schematic diagram for explaining turning assistance of the vehicle 1000 by the control device 200 according to the present embodiment. In the control of the driving force distribution of the left and right wheels of the rear wheels 104 and 106, the control device 200 can generate a yaw moment by generating a driving force difference between the left and right wheels of the rear wheels 104 and 106. Thereby, the turning of the vehicle 1000 can be supported. In the example shown in FIG. 2, the vehicle 1000 is turning counterclockwise by the driver's steering. Here, as shown in the left diagram of FIG. 2, a forward driving force is generated on the right rear wheel 106, and the driving force generated on the left rear wheel 104 is suppressed with respect to the right rear wheel 106. Thus, the moment can be generated in a direction that supports the counterclockwise turning. Thereby, it is possible to support the counterclockwise turning of the vehicle 1000. Further, as shown in the right side of FIG. 2, a forward driving force is generated on the right rear wheel 106, and a driving force is generated backward on the left rear wheel 104, thereby assisting the counterclockwise turning. A moment can be generated in the direction. Thereby, it is possible to support the counterclockwise turning of the vehicle 1000.

  In the adjustment of the steering assist amount by the power steering mechanism 140, when the driver operates the steering wheel 124, the control device 200 adjusts the steering assist amount so as to reduce the driver's load. The turning of the vehicle 1000 can be supported. In the example shown in FIG. 2, the vehicle 1000 is turning counterclockwise by the steering wheel 124 being operated counterclockwise by the driver. Here, the counterclockwise turning of the vehicle 1000 can be supported by assisting the torque necessary for the counterclockwise operation of the steering wheel 124 by the driver with an electric motor or the like.

  Moreover, the control apparatus 200 receives the information output from each sensor from the said sensor. The control apparatus 200 may communicate with each sensor using CAN (Controller Area Network) communication. Note that the functions of the control device 200 according to the present embodiment may be divided by a plurality of control devices. In this case, the plurality of control devices may be connected to each other via a communication bus such as CAN. . According to the control device 200 according to the present embodiment, the amount of energy consumed in turning support of the vehicle can be reduced while suppressing a sense of discomfort associated with the intervention of the steering support control and securing a predetermined turning amount for the steering of the driver. It becomes possible to reduce. Details of the control device 200 will be described later.

<2. Functional configuration of control device>
FIG. 3 is an explanatory diagram illustrating an example of a functional configuration of the control device 200 according to the present embodiment. As shown in FIG. 3, the control device 200 according to the present embodiment includes a first reference yaw rate (γ_Std1) calculation unit 210, a second reference yaw rate (γ_Std2) calculation unit 220, a subtraction unit 230, and a steering control unit. 240, a motor required torque calculation unit 250, and a power steering adjustment unit 260.

(2-1. First reference yaw rate calculation unit)
The first reference yaw rate calculation unit 210 corresponds to a yaw rate that is predicted to occur in the vehicle 1000 when the vehicle 1000 travels along the traveling path based on the curvature R and the vehicle speed V of the traveling path of the vehicle 1000. One reference yaw rate γ_Std1 is calculated. Specifically, the first reference yaw rate calculation unit 210 calculates the curvature R and the vehicle speed V of the traveling path obtained based on the information indicating the shape of the traveling path of the vehicle 1000 output from the external recognition unit 170 using the following formula. By substituting into (1), the first reference yaw rate γ_Std1 is calculated. The first reference yaw rate γ_Std1 is an example of a first state quantity related to the shape of the traveling path of the vehicle 1000.

(2-2. Second reference yaw rate calculation unit)
The second reference yaw rate calculation unit 220 calculates a second reference yaw rate γ_Std2 corresponding to the model value of the yaw rate generated in the vehicle 1000 based on the steering amount and the vehicle speed V. The second reference yaw rate γ_Std2 is an example of a second state quantity related to the traveling state of the vehicle 1000. Specifically, the second reference yaw rate calculation unit 220 solves the following equations (2) and (3) representing a general two-wheel model, thereby solving the second reference yaw rate γ_Std2 (equation ( 2) and γ) in equation (3) are calculated.

The variables and constants are as follows.
<Variable>
γ: vehicle yaw rate V: vehicle speed δ: tire steering angle (front wheel steering angle)
θh: steering angle <constant>
lf: Distance from the vehicle center of gravity to the center of the front wheel lr: Distance from the vehicle center of gravity to the center of the rear wheel m: Vehicle weight Kf: Cornering power (front)
Kr: Cornering power (rear)
Gh: Conversion gain from steering angle to tire rudder angle (steering gear ratio)

  Since the tire steering angle δ in Expression (2) and Expression (3) cannot be directly sensed, the second reference yaw rate calculation unit 220 divides the steering angle θh by the conversion gain Gh using Expression (4). To calculate the tire steering angle δ. A steering gear ratio is used as the conversion gain Gh. Note that the second reference yaw rate calculation unit 220 may calculate the tire steering angle δ from the steering steering angle θh using a general steering model that defines the relationship between the steering steering angle θh and the tire steering angle δ. . The second reference yaw rate calculation unit 220 calculates the second reference yaw rate γ_Std2 by substituting the calculated tire steering angle δ and vehicle speed V into the equations (2) and (3).

  Further, the second reference yaw rate calculation unit 220 may calculate the second reference yaw rate γ_Std2 using the steering steering torque detected by the torque sensor provided in the power steering mechanism 140 as the steering amount. Specifically, the second reference yaw rate calculation unit 220 calculates the tire steering angle δ from the steering steering torque using a general steering model that defines the relationship between the steering steering torque and the tire steering angle δ. Then, the second reference yaw rate γ_Std2 is calculated by substituting the calculated tire steering angle δ and the vehicle speed V into the equations (2) and (3).

(2-3. Subtraction unit)
The subtracting unit 230 subtracts the second reference yaw rate γ_Std2 calculated by the second reference yaw rate calculating unit 220 from the first reference yaw rate γ_Std1 calculated by the first reference yaw rate calculating unit 210 to thereby obtain a difference between γ_Std1 and γ_Std2. A deviation Δγ_Std is obtained. That is, the deviation Δγ_Std is obtained by the following equation (5). The deviation Δγ_Std, which is the difference between γ_Std1 and γ_Std2, is an example of a third state quantity calculated by comparing the first state quantity and the second state quantity.

  The deviation Δγ_Std, which is the third state quantity, is the driving of the left and right wheels performed by the control device 200 as an index for determining the amount of turning support of the vehicle 1000 that is expected to be necessary for the vehicle 1000 to travel along the traveling path. This is used for controlling the power distribution and adjusting the steering assist amount by the power steering mechanism 140.

  The technical scope of the present invention is not limited to examples in which γ_Std1 and γ_Std2 are used as the first state quantity and the second state quantity, respectively. For example, as the first state quantity and the second state quantity, a value indicating the direction of a forward point on the traveling path with respect to the current position at the center of the vehicle 1000 and a value indicating the direction in which the vehicle body of the vehicle 1000 faces the present are used. May be. In that case, the control device 200 may calculate the third state quantity based on an angle formed by the direction of the forward point on the traveling path with respect to the current position at the center of the vehicle 1000 and the direction in which the vehicle body currently faces. Further, as the first state quantity and the second state quantity, a value indicating a position of a point ahead on the traveling path and a value indicating a position of a point on the direction in which the vehicle body of the vehicle 1000 currently faces may be used. . In that case, the control device 200 may calculate the third state quantity based on a lateral deviation of the vehicle 1000 between a point ahead on the traveling path and a point on the direction in which the vehicle body currently faces.

  The forward point on the traveling path is, for example, a reference point on the traveling path that the vehicle 1000 can reach in the future. Further, the point on the direction in which the vehicle body currently faces is, for example, a predetermined gazing point in front of the vehicle detected by the external recognition unit 170. Note that the control device 200 determines the angle between the direction of the forward point on the traveling path with respect to the current position at the center of the vehicle 1000 and the direction in which the vehicle body currently faces, or the forward point on the traveling path and the point on the direction in which the vehicle body currently faces. A value corresponding to the deviation Δγ_Std may be calculated as the third state quantity by converting the lateral deviation of the vehicle 1000 into a parameter corresponding to the tire steering angle δ. Specifically, the value converted as the tire steering angle δ, the vehicle speed V, and γ obtained from the equations (2) and (3) can be obtained as a value corresponding to the deviation Δγ_Std.

(2-4. Flight control unit)
The steering control unit 240 includes a control target yaw rate (γ_Tgt) calculation unit 241, a subtraction unit 243, a feedback yaw rate calculation unit 245, a subtraction unit 247, and a control target moment calculation unit 249.

  The steering control unit 240 calculates a control amount for controlling the driving force distribution of the left and right wheels. Specifically, the steering control unit 240 calculates a control target moment MgTgt, which is a yaw moment generated in the vehicle 1000, as the control amount, and outputs it to the motor required torque calculation unit 250. Thereby, the motor required torque calculation unit 250 controls the driving force distribution of the left and right wheels to generate the calculated control target moment MgTgt. The steering control unit 240 according to the present embodiment adjusts the control target moment MgTgt based on the deviation Δγ_Std that is the difference between the first reference yaw rate γ_Std1 and the second reference yaw rate γ_Std2. Hereinafter, the operation control unit 240 will be described separately for each functional configuration.

  The control target yaw rate calculation unit 241 calculates the control target yaw rate γ_Tgt for the steering control from the following formula (6) representing a general two-wheel model. The control target yaw rate γ_Tgt is calculated by substituting each value for the right side of the equation (6) of the plane two-wheel model. The target stability factor SfTgt in the equation (6) is generally calculated from the following equation (7) as a constant representing the characteristics of the actual vehicle.

The variables and constants are as follows.
<Variable>
γ: vehicle yaw rate V: vehicle speed δ: tire steering angle (front wheel steering angle)
<Constant>
l: vehicle wheel base if: distance from vehicle center of gravity to center of front wheel lr: distance from vehicle center of gravity to center of rear wheel m: vehicle weight Kf: cornering power (front)
Kr: Cornering power (rear)

  The plane two-wheel model represented by Expression (6) is a vehicle model in which the relationship between the vehicle speed V and the steering amount is defined by the target stability factor SfTgt. The target stability factor SfTgt in equation (6) may be set to a value different from the constant calculated from equation (7). The control target yaw rate γ_Tgt is calculated from the equation (6) using the vehicle speed V and the tire steering angle δ as variables. The tire steering angle δ in Expression (6) is calculated by, for example, dividing the steering angle θh by the conversion gain Gh using Expression (4), in the same manner as the calculation process of the second reference yaw rate γ_Std2 described above. . The tire steering angle δ may be calculated from the steering angle θh using a general steering model that defines the relationship between the steering angle θh and the tire steering angle δ. The tire steering angle δ may be calculated from the steering steering torque using a general steering model that defines the relationship between the steering steering torque and the tire steering angle δ.

  The control target yaw rate γ_Tgt used in the operation control unit 240 is calculated from information about the external environment acquired by the external recognition unit 170 configured by a stereo camera or the like or included in external information such as navigation information. May be. Further, the control target yaw rate γ_Tgt used in the operation control unit 240 is calculated using the formula (4) based on the control target yaw rate calculated from the information on the outside environment, the steering angle θh, and the vehicle speed V. The control target yaw rate may be calculated from the weighted state quantity.

  The subtraction unit 243 obtains a difference γ_diff between the second reference yaw rate γ_Std2 and the actual yaw rate γ by subtracting the actual yaw rate γ from the second reference yaw rate γ_Std2. The difference γ_diff is an example of a comparison value calculated by comparing the second reference yaw rate γ_Std2 with the actual yaw rate γ. The difference γ_diff obtained by the subtraction unit 243 is input to the feedback yaw rate calculation unit 245. Here, since the difference γ_diff corresponds to a parameter representing the road surface condition, the subtracting unit 243 corresponds to a component that acquires a parameter representing the road surface condition.

  The feedback yaw rate calculation unit 245 receives the second reference yaw rate γ_Std2 from the second reference yaw rate calculation unit 220 and the actual yaw rate γ from the yaw rate sensor 150. The feedback yaw rate calculation unit 245 calculates a feedback yaw rate γ_F / B for comparison with the control target yaw rate γ_Tgt as the yaw rate generated in the vehicle 1000. Specifically, the feedback yaw rate calculation unit 245 calculates the feedback yaw rate γ_F / B based on the difference γ_diff between the second reference yaw rate γ_Std2 and the actual yaw rate γ. More specifically, the feedback yaw rate calculation unit 245 increases the distribution of the second reference yaw rate γ_Std2 when the difference γ_diff is small, and increases the distribution of the actual yaw rate γ when the difference γ_diff is large. A feedback yaw rate γ_F / B is calculated from the reference yaw rate γ_Std2 and the actual yaw rate γ. The calculated feedback yaw rate γ_F / B is input to the subtraction unit 247.

  The feedback yaw rate calculation unit 245 first calculates the weighting gain κ based on the difference γ_diff between the second reference yaw rate γ_Std2 and the actual yaw rate γ. Then, the feedback yaw rate calculation unit 245 calculates the feedback yaw rate γ_F / B by weighting the second reference yaw rate γ_Std2 and the actual yaw rate γ with the weighting gain κ based on the following equation (8).

  FIG. 4 is an explanatory diagram showing an example of a map M10 representing the relationship between the difference γ_diff between the second reference yaw rate γ_Std2 and the actual yaw rate γ and the weighting gain κ. The feedback yaw rate calculation unit 245 calculates the weighting gain κ based on the difference γ_diff using, for example, the map M10 illustrated in FIG. The value of the weighting gain κ shown in FIG. 4 is between 0 and 1 corresponding to the reliability of the vehicle model used for calculating the second reference yaw rate γ_Std2 expressed by the equations (2) and (3). Value. The difference γ_diff between the second reference yaw rate γ_Std2 and the actual yaw rate γ is used to calculate the weighting gain κ as an index for improving the reliability of the vehicle model. As shown in FIG. 4, the map M10 is set so that the weighting gain κ increases as the absolute value of the difference γ_diff decreases.

  In the map M10 shown in FIG. 4, the threshold TH1_P is a weighting gain κ switching threshold (+ side), the threshold TH2_P is a weighting gain κ switching threshold (+ side), and the threshold TH1_M is a weighting gain κ switching threshold (−side). , Threshold TH2_M indicates a switching threshold (−side) of the weighting gain κ. Note that the magnitude relationship between the positive side threshold value is threshold TH1_P <threshold value TH2_P, and the magnitude relationship between the negative side threshold value is threshold value TH1_M> threshold value TH2_M.

  A region A1 of the map M10 shown in FIG. 4 is a region where the difference γ_diff approaches 0, a region where the S / N ratio is small, and a region where the tire characteristics are linear (dry road surface), and the second reference yaw rate γ_Std2 The reliability of the vehicle model used for the calculation is high. Accordingly, the feedback yaw rate γF / B is calculated with the weighting gain κ = 1 and the distribution of the second reference yaw rate γ_Std2 as 100% according to the equation (8). Thereby, the influence of the noise of the yaw rate sensor 150 included in the actual yaw rate γ can be suppressed, and the sensor noise can be excluded from the feedback yaw rate γ_F / B. Therefore, it is possible to suppress the vibration of the vehicle 1000 and improve the riding comfort.

  In particular, in the driving support control, the amount by which the vehicle 1000 turns based on the estimated travel path from the straight traveling state before the vehicle 1000 enters the corner is foresight controlled. Therefore, not only when the vehicle 1000 is turning but also when the vehicle 1000 is traveling straight, it is possible to move the vehicle 1000 straight without causing vibrations by eliminating the influence of sensor noise.

  As described above, an area where the reliability of the vehicle model used for calculating the second reference yaw rate γ_Std2 can be designated from the difference γ_diff. As shown in FIG. 4, when driving on a dry road surface (high μ) and where the steering amount is small (turning with a low curvature, etc.), the difference γ_diff is weighted so that the weighting gain κ becomes 1. Associating the gain κ is assumed as an example of coefficient setting by the map M10. The planar two-wheel model described above assumes a region where the relationship between tire slip angle and lateral acceleration (tire cornering characteristics) is linear. In the region where the cornering characteristics of the tire are non-linear, the yaw rate and lateral acceleration of the actual vehicle become non-linear with respect to the tire steering angle and slip angle, and the yaw rate defined by the plane two-wheel model deviates from the yaw rate sensed by the actual vehicle. To do. For this reason, if a model that takes into account the nonlinearity of the tire is used, control based on the yaw rate becomes complicated. However, according to the present embodiment, the reliability of the vehicle model used for calculating the second reference yaw rate γ_Std2 differs by γ_diff. It is possible to easily determine based on

  Further, a region A2 of the gain map M10 shown in FIG. 4 is a region where the difference γ_diff is large, which corresponds to a wet road surface, a snow road, or a turn with a high G, and the tire is slipping. It is a limit area. In this region, the reliability of the vehicle model used for calculating the second reference yaw rate γ_Std2 is low, and the difference γ_diff is larger. For this reason, the feedback yaw rate γ_F / B is calculated with the weighting gain κ = 0 and the distribution of the actual yaw rate γ as 100% from the equation (8). Thus, feedback accuracy is ensured based on the actual yaw rate γ, and feedback control of the yaw rate reflecting the behavior of the actual vehicle is performed. Therefore, the turning of the vehicle 1000 can be optimally controlled based on the actual yaw rate γ. Further, since the tire is in a slipping region, even if the signal of the yaw rate sensor 150 is affected by noise, it is difficult for the driver to feel the vibration of the vehicle 1000, so that a reduction in riding comfort can also be suppressed. For the setting of the low μ region A2 shown in FIG. 4, the region where the weighting gain κ = 0 may be determined from the design requirements, and the steering stability performance and the ride when the vehicle 1000 actually travels on the low μ road surface. You may decide experimentally from comfort etc.

  An area A3 of the map M10 shown in FIG. 4 is an area (nonlinear area) in which a transition from a linear area to a limit area is performed, and the second reference yaw rate is considered in consideration of the tire characteristics of the actual vehicle 1000 as necessary. The distribution (weighting gain κ) between γ_Std2 and the actual yaw rate γ is linearly changed. In the transition from the region A1 (high μ region) to the region A2 (low μ region) or in the region transitioning from the region A2 (low μ region) to the region A1 (high μ region), the torque associated with the sudden change of the weighting gain κ In order to suppress fluctuations and fluctuations in the yaw rate, the weighting gain κ is calculated by linear interpolation.

  4 corresponds to a case where the actual yaw rate γ is greater than the second reference yaw rate γ_Std2. For example, when an incorrect parameter is input to the vehicle model used to calculate the second reference yaw rate γ_Std2 and the second reference yaw rate γ_Std2 is erroneously calculated, control is performed using the actual yaw rate γ by the map M10 in the region A4. It can be performed. Further, according to the map M10 in the area A4, even when the second reference yaw rate γ_Std2 is temporarily smaller than the actual yaw rate γ due to the phase delay of the actual yaw rate γ accompanying the filter processing, the actual yaw rate γ Control can be performed using. Note that the range of the set value of the weighting gain κ is not limited to 0 to 1, and the configuration can be changed so that an arbitrary value can be taken as long as the range is established as vehicle control. It falls into the category that can be achieved with technology.

  The control target yaw rate γ_Tgt is input from the control target yaw rate calculation unit 241, and the feedback yaw rate γ_F / B is input from the feedback yaw rate calculation unit 245 to the subtraction unit 247. The subtracting unit 247 obtains the yaw rate correction amount Δγ_Tgt by subtracting the feedback yaw rate γ_F / B from the control target yaw rate γ_Tgt. That is, the yaw rate correction amount Δγ_Tgt is calculated from the following equation (9). The calculated yaw rate correction amount Δγ_Tgt is output to the control target moment calculator 249. The yaw rate correction amount Δγ_Tgt is an example of a comparison result between the control target yaw rate γ_Tgt and the feedback yaw rate γ_F / B.

  The control target moment calculation unit 249 includes an attenuation control moment calculation unit 249a, an inertia compensation moment calculation unit 249b, an attenuation moment gain calculation unit 249c, a differentiation unit 249d, a differentiation unit 249e, an inertia compensation moment gain calculation unit 249f, And an adding unit 249g. Based on the yaw rate correction amount Δγ_Tgt which is the difference between the target yaw rate γ_Tgt and the feedback yaw rate γ_F / B, the control target moment calculation unit 249 uses the control target moment MgTgt as a control amount for controlling the left and right wheel driving force distribution. calculate.

  The control target moment calculation unit 249 calculates the control target moment MgTgt based on the yaw rate correction amount Δγ_Tgt, and corrects the control target moment MgTgt with the adjustment gain, thereby ensuring stability during low-frequency steering steering. In addition, the vehicle response performance at the time of high-frequency steering steering is made compatible, and the steering stability performance is controlled from the viewpoints of both steady behavior and transient behavior when the vehicle turns. Therefore, the control target moment calculation unit 249 includes a damping control moment calculation unit (steady term calculation unit) 249a that calculates a steady target damping moment MgDampTgt, which is a parameter for improving the convergence performance when the vehicle turns, and the vehicle. An inertia compensation moment calculation unit (transient term calculation unit) 249b that calculates a transient target inertia compensation moment MgTransTgt, which is a parameter for compensating for 1000 yaw inertia. The control target moment calculator 249 calculates the control target moment MgTgt by adding the target damping moment MgDampTgt and the target inertia compensation moment MgTransTgt. Hereinafter, calculation of the control target moment MgTgt by the control target moment calculation unit 249 will be described in detail.

  The damping control moment calculation unit 249a calculates a yaw rate correction amount Δγ_Tgt from a coefficient D1 (damping moment calculation coefficient) applied to the yaw rate γ in the following equation (10) in which a well-known plane two-wheel model (yaw motion) is arranged with respect to the yaw moment. Is used to calculate the basic amount MgDamp of the target damping moment MgDampTgt, which is a parameter for improving the convergence performance when the vehicle turns.

That is, the basic amount MgDamp is calculated from the following equation (11). The coefficient D1 corresponds to 2 / V (l _f ² K _f + l _r ² K _r ) applied to γ in the equation (10).

  The damping control moment calculation unit 249a calculates the target damping moment MgDampTgt by multiplying the basic amount MgDamp by the damping moment correction gain DampAdjustGain calculated by the damping moment gain calculation unit 249c. That is, the target damping moment MgDampTgt is calculated from the following equation (12). The calculated target damping moment MgDampTgt is input to the adding unit 249g.

  The damping moment gain calculation unit 249c calculates a damping moment correction gain DampAdjustGain based on the deviation Δγ_Std, and outputs it to the damping control moment calculation unit 249a. Here, the deviation Δγ_Std is used to calculate the damping moment correction gain DampAdjustGain as an index for the amount of support for turning of the vehicle 1000 that is expected to be necessary for the vehicle 1000 to travel along the traveling path.

  A control target moment MgTgt, which is a control amount for controlling the distribution of driving force between the left and right wheels, is obtained by adding the target damping moment MgDampTgt and the target inertia compensation moment MgTransTgt. The target damping moment MgDampTgt is determined according to the damping moment correction gain DampAdjustGain calculated based on the deviation Δγ_Std. Therefore, the control target moment MgTgt is adjusted based on the deviation Δγ_Std. In the present embodiment, the adjustment based on the deviation Δγ_Std of the control target moment MgTgt performed by the operation control unit 240 and the adjustment based on the deviation Δγ_Std of the steering assist amount by the power steering mechanism 140 performed by the power steering adjustment unit 260 described later, It is possible to reduce the amount of energy consumed in turning support of the vehicle while suppressing a sense of incongruity with respect to steering. Details of the calculation of the damping moment correction gain DampAdjustGain based on the deviation Δγ_Std will be described later.

  The inertia compensation moment calculation unit 249b calculates a coefficient T1 (inertia compensation moment calculation coefficient) applied to the yaw acceleration in the equation (10) in which a known plane two-wheel model (yaw motion) is arranged with respect to the yaw moment, the yaw rate correction amount Δγ_Tgt. Is multiplied by the differential value of, the basic amount MgTrans of the target inertia compensation moment MgTransTgt, which is a parameter for compensating the yaw inertia when the vehicle turns, is calculated. That is, the basic amount MgTrans is calculated from the following equation (13). The coefficient T1 corresponds to I (yaw inertia moment of the vehicle) applied to dγ / dt in the equation (10). The differential value of the yaw rate correction amount Δγ_Tgt is obtained by the differentiating unit 249d and input to the inertia compensation moment calculating unit 249b.

  The inertia compensation moment calculator 249b calculates a target inertia compensation moment MgTransTgt by multiplying the basic amount MgTrans by the inertia compensation moment correction gain TransAdjustGain calculated by the inertia compensation moment gain calculator 249f. That is, the target inertia compensation moment MgTransTgt is calculated from the following equation (14). The calculated target inertia compensation moment MgTransTgt is input to the adding unit 249g.

  The inertia compensation moment gain calculation unit 249f calculates an inertia compensation moment correction gain TransAdjustGain based on the transition of the deviation Δγ_Std that is the difference between the first reference yaw rate γ_Std1 and the second reference yaw rate γ_Std2, and the inertia compensation moment calculation unit To 249b. Therefore, the target inertia compensation moment MgTransTgt is adjusted based on the transition of the deviation Δγ_Std. The differential value of the deviation Δγ_Std is obtained by the differentiating unit 249e and input to the inertia compensation moment gain calculating unit 249f. Here, the differential value of the deviation Δγ_Std is used for the calculation of the inertia compensation moment correction gain TransAdjustGain as an index for measuring the degree of the fluctuation of the vehicle body caused by the fluctuation of the road surface state or the fluctuation of the steering.

  As described above, the control target moment calculation unit 249 adjusts the target inertia compensation moment MgTransTgt based on the transition of the deviation Δγ_Std. Here, the adjustment of the target inertia compensation moment MgTransTgt is realized by calculating the inertia compensation moment correction gain TransAdjustGain based on the transition of the deviation Δγ_Std. Hereinafter, calculation of the inertia compensation moment correction gain TransAdjustGain will be described in detail.

  The inertia compensation moment gain calculation unit 249f determines whether or not a state in which the degree of vehicle wobbling is greater than a predetermined level (hereinafter also referred to as vehicle wobbling state) continues based on the transition of the differential value of the deviation Δγ_Std. Determine whether. For example, the greater the absolute value of the differential value of the deviation Δγ_Std, the greater the degree of wobbling of the vehicle body. Therefore, the inertia compensation moment gain calculating unit 249f determines that the absolute value of the differential value of the deviation Δγ_Std is greater than a predetermined value. The vehicle body state is determined to be a vehicle body wobbling state. The inertia compensation moment gain calculation unit 249f, when it is determined that the vehicle body wobbling state continues, is compared with the case where it is not determined that the vehicle body wobbling state continues, A small value is calculated as the correction gain TransAdjustGain. Thereby, the stable performance of the vehicle can be ensured by suppressing the transient movement of the vehicle 1000 that may occur when the degree of wobbling of the vehicle body is large.

  For example, the inertia compensation moment gain calculation unit 249f uses the map M20 illustrated in FIG. 5 to determine whether or not the vehicle body wobbling state continues continuously based on the transition of the differential value of the deviation Δγ_Std. Increase or decrease the counter value. FIG. 5 is an explanatory diagram showing an example of a map M20 that represents the relationship between the differential value of the deviation Δγ_Std that is the difference between the first reference yaw rate γ_Std1 and the second reference yaw rate γ_Std2, and the counter change amount ΔCnt.

  As shown in FIG. 5, the counter change amount ΔCnt is a positive value when the differential value of the deviation Δγ_Std is greater than or equal to the threshold value TH_HIGH, and is negative when the absolute value of the differential value of the deviation Δγ_Std is less than or equal to the threshold value TH_LOW. The map M20 is set so that the threshold value TH_HIGH and the threshold value TH_LOW are such that the threshold value TH_HIGH> the threshold value TH_LOW. Further, when the absolute value of the differential value of the deviation Δγ_Std is larger than the threshold value TH_LOW and smaller than the threshold value TH_HIGH, the map M20 is set so that the counter change amount ΔCnt becomes zero.

  Based on the map M20, the inertia compensation moment gain calculation unit 249f increases the counter value by the positive counter change amount ΔCnt when the absolute value of the differential value of the deviation Δγ_Std is equal to or greater than the threshold value TH_HIGH, and the absolute value of the differential value of the deviation Δγ_Std If the value is less than or equal to the threshold value TH_LOW, the counter value is decreased by a negative counter change amount ΔCnt. Further, based on the map M20, the inertia compensation moment gain calculation unit 249f holds the counter value when the absolute value of the differential value of the deviation Δγ_Std is larger than the threshold value TH_LOW and smaller than the threshold value TH_HIGH. The inertia compensation moment gain calculation unit 249f determines that the vehicle body wobbling state continues continuously when the counter value is equal to or greater than a predetermined threshold value. On the other hand, the inertia compensation moment gain calculation unit 249f determines that the vehicle body wobbling state does not continue continuously when the counter value is smaller than the predetermined threshold value.

  The inertia compensation moment gain calculation unit 249f calculates a smaller value as the inertia compensation moment correction gain TransAdjustGain when the counter value is greater than or equal to a predetermined threshold value, compared to when the counter value is smaller than the predetermined threshold value. The inertia compensation moment gain calculation unit 249f calculates the inertia compensation moment correction gain TransAdjustGain using, for example, the map M30 illustrated in FIG. 6 when the counter value is equal to or greater than a predetermined threshold value. FIG. 6 is an explanatory diagram showing an example of a map M30 representing the relationship between the differential value of the deviation Δγ_Std, which is the difference between the first reference yaw rate γ_Std1 and the second reference yaw rate γ_Std2, and the inertia compensation moment correction gain TransAdjustGain. In the map M30 shown in FIG. 6, the inertia compensation moment correction gain TransAdjustGain is set to a value between 0 and 1 according to the absolute value of the differential value of the deviation Δγ_Std, and the counter value is smaller than a predetermined threshold value. It is set to be 1. For example, in the map M30 shown in FIG. 6, the inertia compensation moment correction gain TransAdjustGain is set to 1 when the absolute value of the differential value of the deviation Δγ_Std is equal to or smaller than the threshold value TH1_T, and the absolute value of the differential value of the deviation Δγ_Std is set to the threshold value. In the case of TH1_T to threshold value TH2_T, the absolute value of the differential value of deviation Δγ_Std is set to decrease, and is set to 0 if the absolute value of the differential value of deviation Δγ_Std is greater than or equal to the threshold value TH2_T.

  The inertia compensation moment gain calculation unit 249f compares the counter value with a value smaller than the predetermined threshold when the counter value is equal to or larger than the predetermined threshold and when the absolute value of the differential value of the deviation Δγ_Std is larger than the predetermined value. Then, a small value may be calculated as the inertia compensation moment correction gain TransAdjustGain. For example, in the map M30 shown in FIG. 6, the inertia compensation moment correction gain TransAdjustGain may be set to be a value smaller than 1 when the absolute value of the differential value of the deviation Δγ_Std is larger than the threshold value TH1_T. As a result, when the degree of wobbling of the vehicle body is small, the response performance of the vehicle 1000 is emphasized, while by suppressing the transient movement of the vehicle 1000 that may occur when the degree of wobbling of the vehicle body is large, the vehicle 1000 Stable performance can be ensured. Further, when the degree of wobbling of the vehicle body is large, by reducing the target inertia compensation moment MgTransTgt, it is possible to reduce the control target moment MgTgt which is a control amount for controlling the driving force distribution of the left and right wheels. Therefore, even in a situation where steering wobbling is included, unnecessary energy consumption can be suppressed by suppressing unnecessary torque control that can occur with the wobbling component. Therefore, the amount of energy consumed to support the turning of the vehicle 1000 can be more effectively reduced.

  In addition, the range of the set value of the inertia compensation moment correction gain TransAdjustGain is not limited to 0 to 1, but the configuration can be changed so that an arbitrary value can be taken as long as the range is established as vehicle control. It falls into the category that can be achieved by the technology of the present invention.

  The addition unit 249g receives the target damping moment MgDampTgt from the damping control moment calculation unit 249a, and receives the target inertia compensation moment MgTransTgt from the inertia compensation moment calculation unit 249b. The adding unit 249g obtains the control target moment MgTgt by adding the target damping moment MgDampTgt and the target inertia compensation moment MgTransTgt. That is, the control target moment MgTgt is calculated from the following equation (15). The calculated control target moment MgTgt is output to the motor required torque calculation unit 250.

(2-5. Required motor torque calculation unit)
The motor required torque calculation unit 250 controls the left and right wheel driving force distribution for realizing the control target yaw rate γ_Tgt from the control target moment MgTgt calculated by the operation control unit 240. Specifically, the motor request torque calculation unit 250 calculates the motor request torque of each of the motors 112 and 114 corresponding to the rear wheels 104 and 106 based on the control target moment MgTgt output from the operation control unit 240. Then, each of the motors 112 and 114 is driven with the calculated required motor torque. Thereby, a turning moment for realizing the control target yaw rate γ_Tgt can be applied to the vehicle by the difference in driving force between the left and right wheels of the rear wheels 104 and 106.

(2-6. Power steering adjustment unit)
The power steering adjustment unit 260 adjusts the steering assist amount by the power steering mechanism 140. Specifically, the power steering adjustment unit 260 adjusts the steering assist amount by the power steering mechanism 140 based on the deviation Δγ_Std that is the difference between the first reference yaw rate γ_Std1 and the second reference yaw rate γ_Std2. For example, the power steering adjustment unit 260 adjusts the steering assist amount by the power steering mechanism 140 by calculating the steering assist raising request value RequestForStearingAssist based on the deviation Δγ_Std and outputting it to the power steering mechanism 140. The power steering mechanism 140 assists in turning by using an assist amount obtained by raising a reference assist amount obtained based on a driver's steering input according to a ratio indicated by a steering assist raising request value RequestForStearingAssist.

(2-7. Adjustment of steering assist amount and adjustment of control target moment MgTgt)
Hereinafter, the adjustment of the steering assist amount by the power steering mechanism 140 performed by the power steering adjustment unit 260 described later will be described together with the adjustment of the control target moment MgTgt performed by the operation control unit 240. Here, the adjustment of the control target moment MgTgt is realized by calculating the damping moment correction gain DampAdjustGain based on the deviation Δγ_Std.

  For example, the power steering adjustment unit 260 calculates the steering assist raising request value RequestForSteeringAssist based on the deviation Δγ_Std using the map M40 shown in FIG. FIG. 7 is an explanatory diagram illustrating an example of a map M40 that represents a relationship between a deviation Δγ_Std that is a difference between the first reference yaw rate γ_Std1 and the second reference yaw rate γ_Std2 and the steering assist raising request value RequestForStearingAssist. In FIG. 7 (FIG. 8), threshold values TH1 to TH4 respectively indicate switching threshold values of the steering assist raising request value RequestForStearingAssist (damping moment correction gain DampAdjustGain). Note that the magnitude relationship between the thresholds TH1 to TH4 is set such that threshold TH1 <threshold TH2 <threshold TH3 <threshold TH4.

  When the deviation Δγ_Std is larger than a predetermined value, the power steering adjustment unit 260 sets the steering assist amount by the power steering mechanism 140 to be larger than the reference assist amount obtained based on the driver's steering input. adjust. For example, as shown in FIG. 7, in the map M40, when the deviation Δγ_Std is larger than the threshold value TH3, the steering assist raising request value RequestForStearingAssist is set to a reference assist amount (control amount) calculated as a reference value by the power steering system. A value corresponding to the premium rate is set.

  On the other hand, the damping moment gain calculation unit 249c calculates the damping moment correction gain DampAdjustGain based on the deviation Δγ_Std, for example, using the map M50 shown in FIG. FIG. 8 is an explanatory diagram showing an example of a map representing a relationship between a deviation Δγ_Std that is a difference between the first reference yaw rate γ_Std1 and the second reference yaw rate γ_Std2 and the damping moment correction gain DampAdjustGain.

  When the deviation Δγ_Std is larger than a predetermined value, the steering control unit 240 adjusts the control target moment MgTgt so as to decrease as the amount adjusted by the power steering adjustment unit 260 of the steering assist amount increases. For example, as shown in FIGS. 7 and 8, in the map M50, when the deviation Δγ_Std is larger than the threshold value TH3, the damping moment correction gain DampAdjustGain is the steering assist raising request value RequestForStearingAssist calculated by the power steering adjustment unit 260. A larger value is set to be smaller.

  According to the control device 200 according to the present embodiment, turning of the vehicle 1000 is supported by controlling the driving force distribution of the left and right wheels and adjusting the steering assist amount by the power steering mechanism 140. Accordingly, it is possible to suppress a sense of incongruity with respect to steering that may occur when assisting turning of the vehicle 1000 is realized only by assisting the steering of the driver by the power steering mechanism 140.

  Further, it is considered that the greater the deviation Δγ_Std, the greater the amount of support for turning the vehicle 1000 that is expected to be necessary. Here, in the turning support by controlling the left and right wheel driving force distribution, more energy is consumed in the control than in the case where the turning of the vehicle is supported by the steering assist by the power steering mechanism 140. According to the control device 200 according to the present embodiment, when the support amount of turning of the vehicle 1000 that is expected to be necessary is relatively large, the turning assistance of the vehicle 1000 is assisted by the driver's steering assistance by the power steering mechanism 140. Is done. Accordingly, the amount of control in controlling the driving force distribution between the left and right wheels is reduced. Therefore, the amount of energy consumed in turning support of the vehicle 1000 can be reduced.

  Here, the threshold value TH3 is appropriately set in the turning support of the vehicle 1000 in consideration of the control of the uncomfortable feeling accompanying the intervention of the steering support control, the priority for reducing the amount of energy consumption, and the securing of the turning amount for a predetermined steering input. obtain. For example, by increasing the threshold TH3, it is possible to perform turning support by the driving force distribution control while delaying the timing at which the steering support control intervenes, and it is possible to suppress the uncomfortable feeling associated with the intervention of the steering support control as much as possible. On the other hand, by reducing the threshold value TH3, it is possible to compensate for the turning amount of the vehicle with respect to a predetermined steering input while intervening steering assist control at an early stage and increasing the effect of reducing the amount of energy consumption. Further, the threshold value TH3 is set to a value of the deviation Δγ_Std such that the turning support amount of the vehicle 1000 that is expected to be necessary becomes the upper limit value of the turning support amount that can be realized by controlling the driving force distribution of the left and right wheels. May be.

  Further, the power steering adjustment unit 260 may adjust the steering assist amount by the power steering mechanism 140 so that the deviation Δγ_Std increases as the deviation Δγ_Std increases when the deviation Δγ_Std is larger than a predetermined value. For example, in the map M40 shown in FIG. 7, the steering assist raising request value RequestForStearingAssist is set so as to increase as the deviation Δγ_Std increases in a section where the deviation Δγ_Std is the threshold value TH3 to the threshold value TH4.

  On the other hand, the operation control unit 240 may adjust the control target moment MgTgt so that the deviation Δγ_Std decreases as the deviation Δγ_Std increases when the deviation Δγ_Std is larger than a predetermined value. For example, in the map M50 shown in FIG. 8, the damping moment correction gain DampAdjustGain is set so as to decrease as the deviation Δγ_Std increases in the section where the deviation Δγ_Std is the threshold value TH3 to the threshold value TH4.

  Accordingly, as the turning support amount of the vehicle 1000 that is expected to be larger increases, the turning assistance of the driver by the power steering mechanism 140 with respect to the turning support amount of the vehicle 1000 by controlling the driving force distribution of the left and right wheels The ratio of the amount of support for turning the vehicle 1000 can be increased. Therefore, the amount of energy consumed in turning support of the vehicle 1000 can be reduced more effectively.

  Further, the power steering adjustment unit 260 may not adjust the steering assist amount by the power steering mechanism 140 when the deviation Δγ_Std is smaller than a predetermined value. For example, as shown in FIG. 7, in the map M40, when the deviation Δγ_Std is smaller than the threshold value TH3, the steering assist raising request value RequestForSteeringAssist is set to zero.

  On the other hand, the operation control unit 240 may adjust the control target moment MgTgt so that the deviation Δγ_Std increases as the deviation Δγ_Std increases when the deviation Δγ_Std is smaller than a predetermined value. For example, in the map M50 shown in FIG. 8, the damping moment correction gain DampAdjustGain is set so as to increase as the deviation Δγ_Std increases in the section where the deviation Δγ_Std is the threshold value TH1 to the threshold value TH2.

  Accordingly, when the turning support amount of the vehicle 1000 that is expected to be necessary is relatively small, the vehicle by controlling the driving force distribution of the left and right wheels according to the turning support amount of the vehicle 1000 that is expected to be necessary. Support for 1000 turns. Further, the turning of the vehicle 1000 is not supported by the driver's steering assist by the power steering mechanism 140. Therefore, the predetermined turning amount accompanying the steering of the driver can be ensured while effectively suppressing the uncomfortable feeling associated with the intervention of the steering assist control.

  Note that the power steering adjustment unit 260 may adjust the steering assist amount by the power steering mechanism 140 by outputting the front wheel steering angle assist request value δReq to the power steering mechanism 140. The power steering mechanism 140 assists the steering by changing the front wheel steering angle based on the assist request value δReq for the front wheel steering angle. Specifically, the power steering adjustment unit 260 calculates the front wheel steering angle assist request value δReq based on the deviation Δγ_Std that is the difference between the first reference yaw rate γ_Std1 and the second reference yaw rate γ_Std2. More specifically, as shown in the following equation (16), the front wheel steering angle assist request value δReq is obtained by multiplying the steering correction gain SteerGain by the front wheel steering angle reference value δStd. For example, the power steering adjustment unit 260 calculates the front wheel steering angle assist request value δReq by changing the steering correction gain SteerGain in the equation (16) between 0 and 1 based on the deviation Δγ_Std. As the steering correction gain SteerGain, for example, 0 may be calculated when the deviation Δγ_Std is smaller than the threshold value TH3, and an assist request value corresponding to the deviation Δγ_Std may be calculated when the deviation Δγ_Std is larger than the threshold value TH3.

<3. Operation>
FIG. 9 is a flowchart illustrating an example of a flow of processing performed by the control device 200 according to the present embodiment. As shown in FIG. 9, first, the first reference yaw rate calculation unit 210 calculates the first reference yaw rate γ_Std1 (step S502). Next, the second reference yaw rate calculation unit 220 calculates the second reference yaw rate γ_Std2 (step S504). Then, the subtracting unit 230 subtracts the second reference yaw rate γ_Std2 from the first reference yaw rate γ_Std1, thereby calculating a deviation Δγ_Std that is a difference between γ_Std1 and γ_Std2 (step S506).

  Subsequently, the damping moment gain calculation unit 249c calculates a damping moment correction gain DampAdjustGain based on the deviation Δγ_Std (step S508). Next, the inertia compensation moment gain calculation unit 249f calculates the inertia compensation moment correction gain TransAdjustGain based on the differential value of the deviation Δγ_Std (step S510). Then, the power steering adjustment unit 260 calculates the steering assist raising request value RequestForStearingAssist based on the deviation Δγ_Std and outputs it to the power steering mechanism 140 (step S512).

  Subsequently, the control target yaw rate calculation unit 241 calculates the control target yaw rate γ_Tgt (step S514). Next, the feedback yaw rate calculation unit 245 calculates the feedback yaw rate γ_F / B (step S516). Then, the subtraction unit 247 calculates the yaw rate correction amount Δγ_Tgt by subtracting the feedback yaw rate γ_F / B from the control target yaw rate γ_Tgt (step S518).

  Subsequently, the damping control moment calculation unit 249a calculates a target damping moment MgDampTgt (step S520). Next, the inertia compensation moment calculation unit 249b calculates the target inertia compensation moment MgTransTgt (step S522). Then, the adding unit 249g adds the target damping moment MgDampTgt and the target inertia compensation moment MgTransTgt to calculate the control target moment MgTgt (step S524).

  In order to confirm the effect of the present invention, a test was performed on each control amount, vehicle behavior, and power consumption in each of an example and a comparative example that perform control according to the present embodiment. According to the present embodiment, the test was performed under the condition that the power steering adjustment unit 260 adjusts the turning assist amount by the power steering mechanism 140 to be larger than the reference assist amount. In such a condition, according to the present embodiment, the control target moment MgTgt is set to be smaller as the amount adjusted by the power steering adjustment unit 260 of the steering assist amount by the damping moment gain calculation unit 249c is larger. Adjusted.

  First, with reference to FIGS. 10 to 13, test results for the example and the comparative example 1 in a state in which the steering does not fluctuate will be described. In FIG. 11 to FIG. 13, the solid line indicates the result of an example in which control is performed by the control device 200 according to the present embodiment described above. In addition, the broken line does not perform the control corresponding to the adjustment of the steering assist amount by the power steering mechanism 140 performed by the power steering adjustment unit 260 according to the present embodiment, but only supports the turning by the difference in driving force between the left and right wheels. The result about the comparative example 1 is shown.

  In both the example and the comparative example 1, a test was performed in the case of running by steering as shown in the upper diagram of FIG. Further, as shown in the lower diagram of FIG. 10, the vehicle speed V is constant.

  The upper diagram of FIG. 11 is a schematic diagram showing test results on the relationship between the steering angle and the yaw rate generated in the vehicle. As shown in the upper diagram of FIG. 11, the yaw rate corresponding to each steering angle is almost the same in both the example and the comparative example 1. Moreover, the lower figure of FIG. 11 is a schematic diagram showing test results regarding the transition of the amount of movement of the vehicle in the lateral direction. As shown in the lower diagram of FIG. 11, the amount of movement of the vehicle in the horizontal direction at each time almost coincided in both the example and the comparative example 1. From this result, even when the adjustment of the steering assist amount by the power steering mechanism 140 according to the present embodiment is performed, the control corresponding to the adjustment of the steering assist amount by the power steering mechanism 140 is not performed. It was confirmed that equivalent vehicle behavior can be realized.

  The upper diagram of FIG. 12 is a schematic diagram showing the test results on the relationship between the yaw rate generated in the vehicle and the total required motor torque. Here, the motor request torque total amount is a total value of the motor request torque of each motor. As shown in the upper diagram of FIG. 12, in the embodiment, the absolute value of the total required torque of the motor corresponding to each yaw rate is substantially smaller than that in the first comparative example. Further, the lower diagram of FIG. 12 is a schematic diagram showing test results on the transition of the absolute value of the total motor required torque. As shown in the lower diagram of FIG. 12, in the example, the absolute value of the motor required torque total amount at each time is generally smaller than that in the first comparative example.

  FIG. 13 is a schematic diagram showing test results regarding the transition of power consumption. The power consumption in the comparative example 1 is calculated based on the total required motor torque. Further, the power consumption in the embodiment is obtained by adding the power corresponding to the raising amount from the reference assist amount of the steering assist amount by the power steering mechanism 140 to the power calculated based on the total required torque amount of the motor. . As shown in FIG. 13, for the example, the area S1 obtained by integrating the power consumption at each time is the same as the area S2 obtained by integrating the power consumption at each time for Comparative Example 1. In comparison, it is generally small. Therefore, the power consumption in the embodiment is generally smaller than the power consumption in Comparative Example 1. From the results, it was confirmed that the power consumption in turning support of the vehicle 1000 can be reduced according to the present invention.

  Next, with reference to FIG. 14 to FIG. 17, test results for the example and the comparative example 2 in a state where the steering is unstable will be described. In FIG. 15 and FIG. 16, the solid line indicates the result for the above-described embodiment. Further, the alternate long and short dash line indicates Comparative Example 2 in that control corresponding to adjustment of the target inertia compensation moment MgTransTgt by the control target moment calculation unit 249 is not performed as compared with the control device 200 according to the present embodiment. .

  In both Example and Comparative Example 2, a test was conducted for the case of running by steering as shown in the upper diagram of FIG. Further, as shown in the lower diagram of FIG. 14, the vehicle speed V is constant.

  The upper diagram of FIG. 15 is a schematic diagram showing the test results on the relationship between the steering angle and the yaw rate generated in the vehicle. As shown in the upper diagram of FIG. 15, the yaw rate corresponding to each steering angle is almost the same in both the example and the comparative example 2. Further, the lower diagram of FIG. 15 is a schematic diagram showing test results on the transition of the amount of movement of the vehicle in the lateral direction. As shown in the lower diagram of FIG. 15, the amount of movement of the vehicle in the lateral direction at each time almost coincided in both Example and Comparative Example 2. From the result, even when the target inertia compensation moment MgTransTgt according to the present embodiment is adjusted, the vehicle behavior equivalent to the case where the control corresponding to the adjustment of the target inertia compensation moment MgTransTgt is not performed can be realized. Was confirmed.

  The upper part of FIG. 16 is a schematic diagram showing test results regarding the transition of the target inertia compensation moment MgTransTgt. As shown in the upper diagram of FIG. 16, in the example, the absolute value of the target inertia compensation moment MgTransTgt at each time is substantially smaller than that in the comparative example 2. Further, the lower diagram of FIG. 16 is a schematic diagram showing test results on the transition of the absolute value of the steering fluctuation component of the total required torque of the motor. The steering noise component of the total required motor torque is the total required motor torque caused by the steering steering fluctuation corresponding to the difference between the steering steering amount shown in the upper diagram of FIG. 14 and the steering steering amount shown in the upper diagram of FIG. It is a component. As shown in the lower diagram of FIG. 16, in the example, the absolute value of the component occupied by the steering fluctuation in the total motor required torque at each time is generally smaller than that in the comparative example 2. Therefore, in the embodiment, compared with the comparative example 2, the absolute value of the motor required torque total amount at each time is substantially small.

  FIG. 17 is a schematic diagram showing test results on the transition of power consumption for each of the example, comparative example 1, and comparative example 2. In addition, the result about the comparative example 1 shown in FIG. 17 is a test result on the conditions similar to the Example and the comparative example 2 about the comparative example 1 which only supports the turning by the driving force difference between the left and right wheels. is there. The power consumption in the comparative example 2 is equivalent to the amount of increase from the reference assist amount of the steering assist amount by the power steering mechanism 140 to the power calculated based on the total required motor torque, similarly to the power consumption in the embodiment. It is obtained by adding the power to be added. As shown in FIG. 17, the area S10 obtained by integrating the power consumption at each time for the example is obtained by integrating the power consumption at each time for each of Comparative Example 1 and Comparative Example 2. Compared with each of the area of the area | region S20 and the area of area | region S30, it becomes small in general. Therefore, the power consumption in the embodiment is substantially smaller than the power consumption in each of the comparative examples 1 and 2. From the result, it was confirmed that the power consumption amount for turning support of the vehicle 1000 can be more effectively reduced by adjusting the target inertia compensation moment MgTransTgt by the inertia compensation moment gain calculating unit 249f according to the present embodiment.

<4. Conclusion>
As described above, according to each embodiment of the present invention, when the deviation Δγ_Std is larger than a predetermined value, the power steering adjustment unit 260 compares it with the reference assist amount obtained based on the driver's steering input. The steering assist amount by the power steering mechanism 140 is adjusted so as to increase. Further, when the deviation Δγ_Std is larger than a predetermined value, the steering control unit 240 adjusts the control target moment MgTgt so that the larger the amount adjusted by the power steering adjustment unit 260 of the steering assist amount, the smaller the deviation Δγ_Std becomes. To do. Accordingly, it is possible to suppress a sense of incongruity with respect to steering that may occur when assisting turning of the vehicle 1000 is realized only by assisting the steering of the driver by the power steering mechanism 140. Further, when the turning support amount of the vehicle 1000 that is expected to be necessary is relatively large, the turning support of the vehicle 1000 is performed by the driver's steering assistance by the power steering mechanism 140. Accordingly, the amount of control in controlling the driving force distribution between the left and right wheels is reduced. Therefore, the amount of energy consumed in turning support of the vehicle 1000 can be reduced.

  In addition, although the example which performs turning assistance control by control of front wheel steering and driving force distribution was demonstrated above, the technical scope of this invention is not limited to the example concerned, For example, 4WS which controls the steering angle of a front-and-rear wheel You may perform turning assistance control by control of this system and driving force distribution.

  Further, the processing described using the flowchart in the present specification may not necessarily be executed in the order shown in the flowchart. Some processing steps may be performed in parallel. Further, additional processing steps may be employed, and some processing steps may be omitted.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can make various modifications or application examples within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

100, 102 Front wheels 104, 106 Rear wheels 108, 110, 112, 114 Motors 116, 118, 120, 122 Wheel speed sensor 124 Steering wheel 130 Steering angle sensor 140 Power steering mechanism 150 Yaw rate sensor 160 Acceleration sensor 170 External recognition unit 200 Control Device 210 First reference yaw rate calculation unit 220 Second reference yaw rate calculation unit 240 Operation control unit 241 Control target yaw rate calculation unit 245 Feedback yaw rate calculation unit 249 Control target moment calculation unit 249a Damping control moment calculation unit 249b Inertia compensation moment calculation unit 249c Damping moment gain calculation unit 249f Inertia compensation moment gain calculation unit 250 Motor required torque calculation unit 260 Power steering adjustment unit 1000 Vehicle

Claims (8)

On the basis of the third state quantity calculated by comparing the first state quantity related to the shape of the traveling path of the vehicle and the second state quantity related to the running state of the vehicle, A power steering adjustment unit for adjusting the assist amount of the rudder,
A steering control unit that adjusts a control amount for controlling the driving force distribution of the left and right wheels based on the third state quantity;
In a vehicle control device comprising:
When the third state amount is larger than a predetermined value, the power steering adjustment unit adjusts the assist amount to be larger than a reference assist amount obtained based on a driver's steering input. The steering control unit adjusts the control amount so that the larger the amount of the assist amount adjusted by the power steering adjustment unit is, the smaller the control amount is. The power steering adjustment unit adjusts the assist amount so that the third state amount increases as the third state amount increases when the third state amount is larger than the predetermined value;
The operation control unit adjusts the control amount so that the third state amount decreases as the third state amount increases when the third state amount is larger than the predetermined value.
The vehicle control device according to claim 1. The power steering adjustment unit does not adjust the assist amount when the third state amount is smaller than the predetermined value,
The operation control unit adjusts the control amount so that the third state amount increases as the third state amount increases when the third state amount is smaller than the predetermined value.
The vehicle control device according to claim 1. The first state quantity is a first reference yaw rate obtained from a curvature of the traveling path and a vehicle speed,
The second state quantity is a second reference yaw rate obtained from a steering amount and the vehicle speed,
The third state quantity is a difference between the first reference yaw rate and the second reference yaw rate.
The control apparatus of the vehicle as described in any one of Claims 1-3. The first state quantity is a value indicating a direction of a forward point on the traveling path with respect to a current position of the center of the vehicle,
The second state quantity is a value indicating a direction in which the vehicle body of the vehicle is currently facing,
The third state quantity is calculated based on an angle formed by a direction of a point ahead of a predetermined distance on the traveling path with respect to a current position of the center of the vehicle and a direction in which the vehicle body of the vehicle is currently facing.
The control apparatus of the vehicle as described in any one of Claims 1-3. The first state quantity is a value indicating a position of a forward point on the traveling path,
The second state quantity is a value indicating the position of a point on the direction in which the vehicle body of the vehicle is currently facing,
The third state quantity is calculated based on a lateral deviation of the vehicle between a point ahead on the traveling path and a point on the direction in which the vehicle body is currently facing.
The control apparatus of the vehicle as described in any one of Claims 1-3. The operation control unit is
A control target yaw rate calculation unit that calculates the control target yaw rate from a vehicle model that defines the relationship between the control target yaw rate of the vehicle, the vehicle speed, and the steering amount;
A feedback yaw rate calculation unit that calculates a feedback yaw rate for comparison with the control target yaw rate as the yaw rate generated in the vehicle;
A control target moment calculator for calculating a control target moment as the control amount based on a comparison result between the control target yaw rate and the feedback yaw rate;
The control target moment calculation unit calculates the control target moment by adding a steady target damping moment and a transient target inertia compensation moment calculated based on the comparison result, and the third state quantity The vehicle control device according to claim 4, wherein the target inertia compensation moment is adjusted based on a transition of the vehicle.   The feedback yaw rate calculation unit obtains the second reference yaw rate and the actual yaw rate detected from the yaw rate sensor, and the comparison value calculated by comparing the second reference yaw rate and the actual yaw rate is small. 8. The feedback yaw rate is calculated from the second reference yaw rate and the actual yaw rate by increasing the distribution of the second reference yaw rate, and increasing the distribution of the actual yaw rate when the comparison value is large. The vehicle control device described in 1.

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