JP6976114B2 - Vehicle control device - Google Patents

Description

The present invention relates to a vehicle control device capable of switching between driver-centered control and vehicle attitude control.

According to Patent Document 1, when the steering speed is high, the moment corresponding to the deviation between the target yaw rate and the actual yaw rate is set as the first inertia compensating moment, and the moment corresponding to the side slip angle corresponding to the front and rear tire positions is set as the second inertia compensating moment. The distribution of the second inertia compensation moment is made larger than the first inertia compensation moment, and when the steering speed is slow, the distribution of the first inertia compensation moment is made larger than the second inertia compensation moment to generate the controlling driving force. Furthermore, by changing the ratio of the first and second inertia compensation moments so that the ratio of the first inertia compensation moment becomes larger on a slippery road surface, the distribution of the front and rear moments changes, and both turning performance and stability are achieved. Is planned.

According to Patent Document 2, the direction of mutual moments with respect to the first controlled variable (understeer suppression) based on the deviation between the target yaw rate and the actual yaw rate and the second controlled variable (oversteer suppression) based on the skid angle velocity. Is selected from the absolute value of the first control amount and the second control amount, whichever is larger, and the sum of the first and second control amounts is controlled by the actuator. By generating a moment as an amount, the controllability of the vehicle is improved.

According to Patent Document 3, the steering characteristics of the rear wheels are changed according to the deviation between the target yaw rate and the actual yaw rate to reduce the deviation, and when the detected skid angle or skid angular velocity becomes large, the target yaw rate is reduced. The deviation from the actual yaw rate is reduced immediately.

According to Patent Document 4, the yaw moment that reduces the deviation between the target slip angle and the actual slip angle of the rear wheels, which is determined according to the degree of turning desired by the driver, and the yaw moment that reduces the deviation between the target yaw rate and the actual yaw rate are The lower the spin state amount of the vehicle, the larger the weight of the yaw moment according to the yaw rate deviation, and the higher the spin state amount, the larger the weight of the yaw moment according to the slip angle deviation.

Japanese Unexamined Patent Publication No. 2016-190536 Japanese Patent No. 4890062 Japanese Unexamined Patent Publication No. 5-301574 Japanese Unexamined Patent Publication No. 9-99826

In Patent Document 1, when the moment distribution is switched according to the steering speed, it depends on the steering of the driver. Therefore, for example, if the driver has a slow steering speed, the effect of the second inertia compensation moment cannot be fully exerted. It impairs stability.
In Patent Document 2, when a moment is generated only by the sideslip angular velocity without using the sideslip angle, when a "scene of gradually skidding" as seen on a low μ road surface such as a snowy road is encountered, the sideslip angular velocity is used. The controlled amount according to the yaw rate deviation becomes larger than the controlled amount, which may promote spin.

In Patent Document 3, lowering the target yaw rate according to the skid angle and the skid angular velocity is effective in suppressing spin, but may increase the risk of drift out.
In Patent Document 4, for example, when the target slip angle is calculated from the vehicle speed and the steering angle, the target slip angle changes when the driver's steering becomes unstable when the spin state amount is high, so that the target slip angle is adjusted according to the slip angle deviation. The effect of spin suppression by the yaw moment may be impaired.

The present invention has been made to solve the above problems, and in a vehicle having a means by which the driver can arbitrarily determine the turning characteristics, a yaw for suppressing spin when there is a danger of spin. It is an object of the present invention to provide a vehicle control device capable of achieving both driver-based vehicle motion and attitude control-based vehicle motion by commanding a moment, and achieving both turning performance and stability.

The vehicle control device of the present invention is
The yaw response characteristic setting means 16 that can change the yaw response characteristic of the vehicle 1 by the operation of the driver, and the road surface friction coefficient estimation means 17 that estimates the road surface friction coefficient from at least the actual lateral acceleration.
The target yaw rate calculation means 24 for calculating the target yaw rate from the yaw response characteristics and the road surface friction coefficient, and
The skid angular velocity calculating means 27 for calculating the skid angular velocity from at least the vehicle speed, the actual yaw rate, and the actual lateral acceleration of the vehicle 1 and the like.
A vehicle control device including at least a skid angle calculating means 28 for calculating a skid angle from the skid angular velocity.
A set value-oriented moment command unit 18 for calculating a yaw moment based on the target yaw rate and / or a yaw moment based on the deviation between the target yaw rate and the actual yaw rate.
The skid-corresponding moment command unit 19 that calculates the yaw moment based on the skid angular velocity and the skid angle,
A command yaw moment calculation unit 21 that calculates a command yaw moment commanded to the vehicle 1 from yaw moments calculated by each of the set value-oriented moment command unit 18 and the skid-corresponding moment command unit 19.
It is provided with a control drive force control device 23 that controls a traveling drive source of the vehicle using a given control drive command and the command yaw moment.
The set value-oriented moment command unit 18 determines the yaw moment according to the yaw response characteristic set in the yaw response characteristic setting means, the steering angle, and the vehicle speed, and the side slip corresponding moment command unit 19 sets the yaw response characteristic. The yaw moment is calculated based on the sideslip angular velocity and the magnitude of the sideslip angle regardless of the yaw response characteristics, the steering angle, and the vehicle speed set in the means 16.

According to the vehicle control device having this configuration, in the vehicle 1 having the yaw response characteristic setting means 16 which is a means by which the driver can arbitrarily determine the turning characteristic, the target turning characteristic arbitrarily set by the driver is set. The yaw moment for realization is commanded by the set value-oriented moment command unit 18, and when there is a danger of spin regardless of the target turning characteristic, the yaw moment for suppressing spin is commanded by the skid-compatible moment command unit 19. .. As a result, "driver-centered vehicle motion" and "posture control-based vehicle motion" are compatible, and turning performance is compatible with stability.

Specifically, the set value-oriented moment command unit 18 calculates the yaw moment based on the deviation between the target yaw rate and the actual yaw rate with the first moment command unit 18a that calculates the yaw moment based on the target yaw rate. It has a second moment command unit 18b for calculation.
The first moment command unit 18a is a command unit that calculates the yaw moment that realizes the target yaw rate, and performs feedforward control. The second moment command unit 18b calculates the yaw moment that reduces the deviation between the target yaw rate and the actual yaw rate, and performs feedback control.
The sideslip corresponding moment command unit 19 calculates the yaw moment for suppressing spin from at least the sideslip angular velocity calculated from the vehicle speed, the actual yaw rate, and the actual lateral acceleration, and the magnitude of the sideslip angle. That is, spin control is performed.
In this case, when the road surface friction coefficient is high, the yaw moment calculated by the first moment command unit 18a becomes dominant and the turning characteristics requested by the driver are realized, and the second moment command unit 18b realizes the turning characteristics. The calculated yaw moment supports the first moment command unit and suppresses driftout. However, if it is determined from the skid angular velocity and the skid angle that there is a risk of spin, the yaw moment calculated by the skid-corresponding moment command unit 19 becomes dominant and commands the spin in advance. prevent. In other words, the skid-corresponding moment command unit 19 commands the yaw moment in the direction opposite to the turning direction at an early stage when there is a risk of spin regardless of the driver's intention.
As a result, it is possible to achieve both driver-based vehicle motion and posture control-based vehicle motion, and to achieve both turning performance and stability.

In the present invention, the side slip corresponding moment command unit 19 has a threshold value Β _{T for the side slip angular velocity and a threshold value Β T} for the side slip angle, and the size of the side slip angular velocity exceeds the threshold value Β _{T for the side slip angular velocity.} Or, the threshold value Β _{T for the skid angle.}
The yaw moment may be output according to the magnitude of the skid angle exceeded.
By providing such a dead zone, it is possible to adjust the command timing.

In the case of this configuration, the side slip corresponding moment command unit 19 is provided with a _{threshold value Β T} for the side slip angle _{velocity and a threshold value Β T} for the side slip angle so as to change the values according to the road surface friction coefficient. May be good.
Threshold · beta _T in accordance with the road surface friction _coefficient, can be controlled command timing of yaw moment by changing the beta _T.

In the present invention, the side slip corresponding moment command unit 19 has a threshold value Β _{T for the side slip angular velocity and a threshold value Β T} for the side slip angle, respectively, when the road surface friction coefficient is smaller than the value before a predetermined time. The threshold _{values, Β T} , and Β _T may be reduced, and if the road surface friction coefficient is larger than the value before a predetermined time, the respective threshold values, Β _T , and Β _T may be increased.
By reducing the threshold values, Β _{T and Β T} , spin can be quickly suppressed on a low μ path.

In the present invention, the side slip corresponding moment command unit 19 may command the yaw moment only when the vehicle 1 is inward with respect to the turning direction.
This makes it possible to prevent interference with the set value-oriented moment command unit 18, specifically, interference with the second moment command unit 18b.
The "when the vehicle turns inward with respect to the turning direction" is, in other words, when the skid angular velocity or the skid angle turns outside with respect to the direction of the vehicle 1.

In the present invention, the target yaw rate calculation means 24 is set in the yaw response characteristic setting means 16 when the road surface friction coefficient estimated by the road surface friction coefficient estimation means 17 is smaller than the value before a predetermined time. When the yaw response characteristic is closer to the original yaw response characteristic of the vehicle and the road surface friction coefficient is larger than the value before a predetermined time, the yaw response characteristic set in the yaw response characteristic setting means 16 from the original yaw response characteristic of the vehicle. You may try to get closer to.
When the coefficient of friction on the road surface becomes small, the safety can be improved by reducing the effect of the first moment command unit 18a.
Specifically, when the road surface friction coefficient μ is low, the yaw response characteristic arbitrarily set by the driver as μ decreases is brought closer to the yaw response characteristic originally possessed by the vehicle 1, so that the first moment command unit The yaw moment calculated at 18a becomes zero. The second moment command unit 18b generates a yaw moment so as to follow the actual yaw rate to the target yaw rate that realizes the original yaw response characteristic of the vehicle, and the side slip corresponding moment command unit 19 is provided at each of the sideslip angular velocity and the sideslip angle. By lowering the thresholds, Β _T , and Β _T as μ decreases, it becomes easier to generate yaw moments and spin is suppressed.

The vehicle control device of the present invention includes a yaw response characteristic setting means that can change the yaw response characteristic of the vehicle by the operation of the driver, a road surface friction coefficient estimation means that estimates the road surface friction coefficient from at least the actual lateral acceleration, and the yaw response characteristic. A target yaw rate calculating means for calculating the target yaw rate from the road surface friction coefficient, a skidding angular velocity calculating means for calculating the skidding angular velocity from at least the vehicle speed, the actual yaw rate, and the actual lateral acceleration, and at least the skidding angular velocity calculated from the skidding angular velocity. A setting for calculating a yaw moment based on the target yaw rate and / or a yaw moment based on the deviation between the target yaw rate and the actual yaw rate. The yaw calculated by the value-oriented moment command unit, the sideslip corresponding moment command unit that calculates the yaw moment based on the sideslip angular velocity and the sideslip angle, and the set value-oriented moment command unit and the sideslip correspondence moment command unit. A command yaw moment calculation unit that calculates a command yaw moment commanded to the vehicle from a moment, and a control drive force control device that controls a traveling drive source of the vehicle using a given control drive command and the command yam moment. The set value-oriented moment command unit determines the yaw moment according to the yaw response characteristic set in the yaw response characteristic setting means, the steering angle, and the vehicle speed, and the skid-corresponding moment command unit sets the yaw response characteristic. The driver can arbitrarily determine the turning characteristics in order to calculate the yaw moment based on the sideslip angular velocity and the magnitude of the sideslip angle regardless of the yaw response characteristics and the steering angle and the vehicle speed set in the means. In a vehicle with possible means, when there is a danger of spinning, a yaw moment is commanded to suppress the spin, and both the driver-centered vehicle motion and the attitude control-based vehicle motion are compatible, and turning performance and stability are achieved. It is possible to achieve both sex.

It is explanatory drawing which shows the conceptual structure of the control system of the vehicle which carries the vehicle control device which concerns on one Embodiment of this invention. It is a block diagram which shows the conceptual structure of the vehicle control device. It is a glass showing the magnitude of the yaw moment commanded by each yaw moment calculation means due to the change of the road surface friction coefficient when the sign steering is performed by the vehicle control device. It is a graph showing the relationship between the yaw response characteristic gain which determines the yaw response characteristic and the yaw moment calculated by the first yaw moment calculation means in the first yaw moment calculation means of the vehicle control device. It is a graph showing the relationship between the yaw rate deviation and the yaw moment in the second yaw moment calculation means of the vehicle control device. It is a graph which shows the relationship between the side slip angular velocity and the yaw moment in the third yaw moment calculation means of the vehicle control device. It is a graph which shows the relationship between the side slip angle and the yaw moment in the third yaw moment calculation means of the vehicle control device. It is a graph which shows the slip of a vehicle while turning. It is sectional drawing which shows an example of an in-wheel motor drive device.

An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view of a vehicle 1 in which an in-wheel motor drive device 3 is mounted on four wheels. The in-wheel motor drive device may be abbreviated as "IWM" in the figure. As shown in FIG. 9, for example, the in-wheel motor drive device 3 decelerates and transmits the wheel bearing 5, the electric motor 4, and the rotational output of the electric motor 4 to the hub wheel 5a, which is the rotating wheel of the wheel bearing 5. A speed reducer 6 is provided, and the wheel of the wheel 2 is attached to the hub wheel 5a. The electric motor 4 is an AC motor such as a synchronous motor, and has a stator 4a and a rotor 4b. The in-wheel motor drive device 3 includes a wheel rotation speed sensor 7.

In FIG. 1, the vehicle 1 includes an accelerator / brake sensor 11, a vehicle speed sensor 12, a steering angle sensor 13, a yaw rate sensor 14, a lateral acceleration sensor 15, and a yaw response characteristic setting means 16, and these signals are main. Is input to the ECU 8. The inverter device 9 of each wheel 2 is instructed by the control driving force control device 23 via the ECU 8 and the yaw moment calculation device 20. The accelerator / brake sensor 11 collectively refers to an accelerator sensor that detects the amount of depression of the accelerator pedal and a brake sensor that detects the amount of depression of the brake pedal. The yaw response characteristic setting means 16 is a means capable of arbitrarily setting yaw response characteristics in a plurality of stages or steplessly by operating a predetermined operation switch (not shown) provided in the vehicle interior by a driver. , It has a means for performing an operation and a means for storing the setting characteristics. The yaw response characteristic setting means 16 may be configured to switch between two stages, for example, a sporty running mode and a normal running mode.

The vehicle 1 has a road surface friction coefficient estimation unit 17 that estimates the road surface friction coefficient from a signal output from the ECU 8, a set value-oriented moment command unit 18 and a skid-compatible moment command unit 19 that constitute the yaw moment calculation device 20, and commands. It has a yaw moment calculation unit 21. The set value-oriented moment command unit 18 includes a first moment command unit 18a for calculating a yaw moment from a signal output from the ECU 8 and a second moment command unit 18b. The yaw moments calculated from these command units 18 and 19 are input to the command yaw moment calculation unit 21 that calculates the yaw moment commanded to the vehicle 1. After the commanded yaw moment is determined, the inverter torque command device 22 outputs a current equivalent to the command torque to the inverter device 3 of each wheel 2 constituting the control driving force control device 23.

The set value-oriented moment command unit 18 is a means for calculating the yaw moment based on the target yaw rate and / or the yaw moment based on the deviation between the target yaw rate and the actual yaw rate. The yaw moment is determined according to the set yaw response characteristics, steering angle, and vehicle speed.
The sideslip corresponding moment command unit 19 is a means for calculating the yaw moment based on the sideslip angular velocity and the sideslip angle, and the sideslip is irrespective of the yaw response characteristics and the steering angle and the vehicle speed set in the yaw response characteristic setting means 16. The yaw moment is calculated based on the angular velocity and the magnitude of the skid angle.

FIG. 2 is a schematic diagram showing the system configuration of the vehicle 1 mainly using the vehicle control device 20. In this vehicle 1, the road surface friction coefficient obtained from the road surface friction coefficient estimation unit 17 is used, and the first moment command unit 18a and the second moment command unit 18b constituting the set value-oriented moment command unit 18 and the skid-corresponding moment. The command value of the yaw moment is output from each of the three command units including the command unit 19. These yaw moments are input to the command yaw moment calculation unit 21, and the command yaw moment calculation unit 21 outputs one command yaw moment.
The control driving force calculation device 32 calculates the control driving force to be distributed to each wheel 2 using the command yaw moment based on the accelerator / brake torque command commanded from the ECU 8. The inverter torque command device 33 receives the control driving force and generates an inverter torque command value to be output to the inverter device 9 of each wheel 2. The control driving force calculation device 32 and the inverter torque command device 33 constitute the control drive force control device 23.
The actual lateral acceleration is input from the ECU 8 to the road surface friction coefficient estimation unit 17. Since the magnitudes of the actual lateral acceleration and the road surface friction coefficient are approximately the same, the road surface friction coefficient estimation unit 17 estimates the road surface friction coefficient from the actual lateral acceleration and outputs it.

The first moment command unit 18a has a target yaw rate calculation means 24 and a first yaw moment calculation means 31. The vehicle speed, steering angle, and yaw response characteristics are input to the target yaw rate calculation means 24 from the ECU 8, and the road surface friction coefficient is input from the road surface friction coefficient estimation means 17. The target yaw rate calculation means 24 calculates the target yaw rate from these values and outputs the target yaw rate to the yaw rate deviation calculation means 25 constituting the first moment command unit 18a and the second moment command unit 18b. The first yaw moment calculation means 18a to which the target yaw rate is input calculates the yaw moment for realizing the target yaw rate and outputs it to the command yaw moment calculation unit 21.

The target yaw rate is input to the yaw rate deviation calculating means 25 in the second moment command unit 18b, and the actual yaw rate is input from the ECU 8. The yaw rate deviation calculation means 25 calculates the yaw rate deviation from these values and outputs the yaw rate deviation to the second yaw moment calculation means 26 constituting the second yaw moment command unit 18b. The second yaw moment calculation means 26 calculates a yaw moment that reduces the input yaw rate deviation, and outputs the yaw moment to the command yaw moment calculation unit 21.

The vehicle speed, the actual yaw rate, and the actual lateral acceleration are input from the ECU 8 to the sideslip angular velocity calculation means 27 in the sideslip corresponding moment command unit 19. The sideslip angular velocity calculation means 27 calculates the sideslip angular velocity from these values and outputs them to the sideslip angle calculation means 28 and the third yaw moment calculation means 29. The sideslip angle calculation means 28 calculates the sideslip angle from the input sideslip angular velocity. The side slip angle velocity, the side slip angle, and the road surface friction coefficient are input to the third yaw moment calculation means 29. Third yaw moment calculating unit 29 is not equipped with a threshold · beta which changes according to the road surface friction coefficient _{T (threshold} for slip angular velocity) and the threshold value beta _{T (threshold} value corresponding to the side slip angle), the threshold value for slip angular velocity -For _{the magnitude exceeding Β T} and the skid angle, the yaw moment is calculated according to the magnitude exceeding the _{threshold Β T and output to the command yaw moment calculation unit 21.}

The command yaw moment calculation unit 21 is one yaw according to a predetermined rule from the yaw moments output from each of the first yaw moment calculation means 31, the second yaw moment calculation means 26, and the third yaw moment calculation means 29. The moment is calculated and output to the control driving force calculation device 32. In this embodiment, the yaw moments calculated by the first to third yaw moment calculation means 31, 26, 29 are simply added to obtain the one yaw moment.
The control driving force calculation device 32 inputs the input yaw moment and the accelerator / brake command torque output from the ECU 8, calculates the control driving force commanded to each wheel 2 from these values, and inverts the inverter torque. Output to the command device 33.
When the command control driving force of each wheel 2 is input from the control drive force calculation device 32, the inverter torque command device 33 converts the command control drive force corresponding to these command control drive forces into an inverter torque command value and the inverter device of each wheel 2. Command 9. The inverter device 2 of each wheel 2 converts the input torque command value into a current value, and drives the in-wheel motor drive device 3 mounted on each wheel 2.

The outline of the operation of the above configuration will be described. This vehicle control device has a yaw response characteristic setting means 16 as a means by which the driver can arbitrarily determine the turning characteristic, and the yaw for realizing the target turning characteristic arbitrarily set by the driver. When there is a danger of spinning regardless of the target turning characteristics, the moment and the yaw moment to suppress the spin are commanded to achieve both "driver-centered vehicle motion" and "attitude control-based vehicle motion". Achieves both turning performance and stability.

Specifically, the vehicle 2 has a set value-oriented moment command unit 18 as a means for determining a target yaw rate based on the yaw response characteristics arbitrarily set by the driver in the yaw response characteristic setting means 16, which is the target. The first moment command unit 18a (which performs feed forward control) that calculates the yaw moment that realizes the yaw rate, and the second moment command unit 18b (feedback control) that calculates the yaw moment that reduces the deviation between the target yaw rate and the actual yaw rate. It has at least a sideslip corresponding moment command unit 19 (which performs spin control) that calculates the yaw moment that suppresses spin from the sideslip angular velocity calculated from the vehicle speed, the actual yaw rate, and the actual lateral acceleration. It also includes a road surface friction coefficient estimation unit 17 that estimates the road surface friction coefficient from at least the actual lateral acceleration.

When the road friction coefficient is high, the yaw moment calculated by the first moment command unit 18a becomes dominant to realize the turning characteristics requested by the driver, and the yaw calculated by the second moment command unit 18b is realized. The moment supports the first moment command unit 18a and suppresses drift-out. However, when it is determined from the sideslip angular velocity and the sideslip angle that there is a risk of spin, the yaw moment calculated by the sideslip corresponding moment command unit 19 becomes dominant to prevent spin.
As described above, since the command yaw moment calculation means 21 simply adds the yaw moments calculated by the first to third yaw moment calculation means 31, 26, 29, the skid-corresponding moment unless spinning is performed. The command yaw moment of the command unit 19 is zero, and the command yaw moment of the first moment command unit 18a becomes dominant. However, when there is a sign of spin, the skid correspondence moment is higher than the command yaw moment of the first moment command unit 18a. The command yaw moment of the command unit 19 is overwhelmingly large and dominant. However, the command yaw moment of the first moment command unit 18a does not become zero.

When the road friction coefficient is low, the yaw calculated by the first moment command unit 18a is obtained by approaching the yaw response characteristic originally possessed by the vehicle 1 from the yaw response characteristic arbitrarily set by the driver as μ decreases. The moment becomes zero. The second moment command unit 26 generates a yaw moment so as to follow the actual yaw rate to the target yaw rate that realizes the original yaw response characteristic of the vehicle, and the side slip corresponding moment command unit 19 is provided at each of the sideslip angular velocity and the sideslip angle. By lowering the thresholds, Β _T , and Β _T as μ decreases, it becomes easier to generate yaw moments and spin is suppressed.

Hereinafter, the details of the action and the supplement of the above configuration will be given.
FIG. 3 shows yaws commanded by the first to third yaw moment calculation means 31, 26, 29 due to a change in the road surface friction coefficient during sine steering (steering that changes the direction of steering in a sine wave shape). It shows the magnitude of the moment. When the road surface friction coefficient is large, the first yaw moment calculated by the first yaw moment calculating means 31 is the largest, the second yaw moment calculated by the second yaw moment calculating means 26 is smaller, and the third yaw moment is calculated. The third yaw moment calculated by means 29 becomes zero unless it becomes a spin tendency. As the coefficient of friction of the road surface decreases, the risk of spin increases, so the third yaw moment becomes the largest, the second yaw moment follows the third yaw moment, and the first yaw moment is extremely small or zero. become.

FIG. 4 is a graph showing the relationship between the yaw response characteristic gain that determines the yaw response characteristic and the yaw moment calculated by the first yaw moment calculation means 31 in the first yaw moment calculation means 31. The ● mark indicates the yaw response characteristic gain arbitrarily set by the driver, and the ○ mark indicates the yaw response characteristic gain that has changed as the road friction coefficient decreases. Assuming that the steering angle and the vehicle speed are the same, increasing the yaw response characteristic gain produces an inward turning yaw moment, and decreasing the yaw response characteristic gain produces an outward turning yaw moment. Due to the decrease in the road friction coefficient, the yaw response characteristic gain (●) arbitrarily set by the driver approaches the original yaw response characteristic gain (1) of the vehicle. On the contrary, if the road surface friction coefficient increases, the yaw response characteristic gain (1) originally set by the driver approaches the yaw response characteristic gain (●) arbitrarily set by the driver.

FIG. 5 is a graph showing the relationship between the yaw rate deviation and the yaw moment in the second yaw moment calculating means 26. When the target yaw rate is larger than the actual yaw rate, the vehicle 1 tends to be prone, and this is solved by generating the yaw moment inward when turning. On the contrary, when the target yaw rate is smaller than the actual yaw rate, the vehicle 1 tends to spin, and the yaw moment is generated outward by turning to solve the problem.

FIG. 6 shows the relationship between the sideslip angular velocity and the yaw moment in the third yaw moment calculation means 29. When the side slip angular velocity, which changes from moment to moment _{, exceeds the threshold value, Β T} , the yaw moment is commanded according to the excess magnitude. However, when the road surface friction coefficient decreases, the yaw moment can be immediately generated and the spin can be suppressed even on a low μ road by reducing the _{threshold value Β T.}

FIG. 7 shows the relationship between the skid angle and the yaw moment in the third yaw moment calculation means 29. When the side slip angle, which changes from moment to moment _{, exceeds the threshold value, Β T} , the yaw moment is commanded according to the excess magnitude. However, when the road surface friction coefficient decreases, the yaw moment can be immediately generated and spin can be suppressed even on a low μ road by reducing the _{threshold value Β T.}

FIG. 8 shows the slip of the vehicle 1 while turning. The figure on the left side shows a state in which the vehicle 1 faces the outside of the turn with respect to the tangential direction of the turning circle, and this state is "US (understeer, drift-out state)". The figure on the right side shows a state in which the vehicle faces the inside of the turn with respect to the tangential direction of the turning circle, and this state is "OS (oversteer, spin state)". In the third yaw moment calculation means 29, the yaw moment is commanded only in the state on the right side of FIG. 8, that is, in the OS.

Here, the formula for obtaining the skid angular velocity is shown in (1), and the formula for finding the skid angle is shown in (2). The skid angular velocity is calculated from the actual lateral acceleration Gy, the vehicle speed V, and the actual yaw rate ya, and the skid angle is calculated from the time integral of the skid angular velocity.

According to the vehicle control device of this embodiment, the yaw moments of the first moment command unit 18a and the second moment command unit 18b, which have a high priority for steering by the driver, and the sideslip, which has a high priority for attitude control, are supported. By changing the magnitude of the yaw moment of the moment command unit 19 according to the coefficient of friction of the road surface, both turning performance and stability are achieved.

Although the embodiment has been described when applied to a four-wheel drive vehicle, the present invention can be applied to a two-wheel drive vehicle having front wheels or rear wheels. Further, the present invention is not limited to a vehicle provided with an in-wheel motor drive device 3, and any vehicle in which the left and right wheels 2 can be driven independently has a drive source such as an electric motor on a chassis (not shown). It can also be applied to vehicles.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 ... Vehicle 2 ... Wheel 3 ... In-wheel motor drive device 4 ... Electric motor 8 ... ECU
9 ... Inverter device 11 ... Accelerator / brake sensor 12 ... Vehicle speed sensor 13 ... Steering angle sensor 14 ... Yaw rate sensor 15 ... Lateral acceleration sensor 16 ... Yaw response characteristic setting means 17 ... Road surface friction coefficient estimation unit 18 ... Set value-oriented moment command unit 18a ... 1st moment command unit 18b ... 2nd moment command unit 19 ... Side slip corresponding moment command unit 20 ... Yaw moment calculation device 21 ... Command yaw moment calculation unit 24 ... Target yaw rate calculation means 25 ... Yaw rate deviation calculation means 26 ... Second Yaw moment calculation means 27 ... Side slip angular velocity calculation means 28 ... Side slip angle calculation means 29 ... Third yaw moment calculation means 31 ... First yaw moment calculation means 32 ... Control driving force calculation device 33 ... Inverter torque command device

Claims (6)

A yaw response characteristic setting means that can change the yaw response characteristics of the vehicle by the operation of the driver,
A road surface friction coefficient estimation means that estimates the road surface friction coefficient from at least the actual lateral acceleration,
A target yaw rate calculation means for calculating a target yaw rate from the yaw response characteristics and the road surface friction coefficient, and
A sideslip angular velocity calculating means for calculating the sideslip angular velocity from at least the vehicle speed, the actual yaw rate, and the actual lateral acceleration of the vehicle.
A vehicle control device including at least a skid angle calculating means for calculating a skid angle from the skid angular velocity.
A set value-oriented moment command unit that calculates the yaw moment based on the target yaw rate and / or the yaw moment based on the deviation between the target yaw rate and the actual yaw rate.
A skid-corresponding moment command unit that calculates the yaw moment based on the skid angular velocity and the skid angle,
A command yaw moment calculation unit that calculates a command yaw moment commanded to the vehicle from yaw moments calculated by each of the set value-oriented moment command unit and the skid-corresponding moment command unit.
It is equipped with a control drive force control device that controls a traveling drive source of the vehicle using a given control drive command and the command yaw moment.
The set value-oriented moment command unit determines the yaw moment according to the yaw response characteristic set in the yaw response characteristic setting means, the steering angle, and the vehicle speed, and the side slip corresponding moment command unit is used in the yaw response characteristic setting means. set regardless the yaw response characteristic and the steering angle and the vehicle speed, the yaw moment calculated based on the magnitude of the sideslip angle and the slip angular velocity,
When the road surface friction coefficient estimated by the road surface friction coefficient estimating means is smaller than the value before a predetermined time, the target yaw rate calculating means is based on the yaw response characteristics set in the yaw response characteristic setting means to be original to the vehicle. A vehicle control device that approaches the yaw response characteristic and, when the road surface friction coefficient is larger than the value before a predetermined time, approaches the yaw response characteristic set in the yaw response characteristic setting means from the vehicle's original yaw response characteristic. In the vehicle control device according to claim 1, the set value-oriented moment command unit is based on a first moment command unit that calculates a yaw moment based on the target yaw rate and a deviation between the target yaw rate and the actual yaw rate. A vehicle control device having a second moment command unit for calculating the yaw moment. In the vehicle control device according to claim 1 or 2, the sideslip corresponding moment command unit includes a threshold value Β _{T for the sideslip angular velocity and a threshold value Β T} for the sideslip angle, and the threshold value for the sideslip angular velocity. A vehicle control device that outputs a yaw moment according to a magnitude that exceeds the skid angular velocity of Β _{T , or a threshold value Β T for the skid angle that exceeds the skid angle.} In the vehicle control device according to claim 3, the skid-corresponding moment command unit _{changes the threshold value Β T for the skid angular velocity and the threshold Β T} for the skid angle according to the road surface friction coefficient. Vehicle control device to let. In the vehicle control device according to claim 3 or 4, the skid-corresponding moment command unit is provided with a threshold value Β _{T for the skid angular velocity and a threshold value Β T} for the skid angle, and the road surface friction coefficient is set for a predetermined time. Previous small when each threshold · beta than the value _T, beta _T was reduced, the road surface friction coefficient is a predetermined time before the case of larger than the value each threshold · beta _T, the vehicle control to increase the beta _T Device. In the vehicle control device according to any one of claims 1 to 4, the skid-corresponding moment command unit commands a yaw moment only when the vehicle turns inward with respect to the turning direction. Control device.

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