JP2006327335A - Torque distribution controller for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a torque distribution controller for a vehicle capable of obtaining higher turning performance by realizing neutral steering even during driving on a split μ road. <P>SOLUTION: The vehicle includes: a torque distribution controller for controlling at least one of torque distribution of front and rear wheels, and left and right wheels; and split μ road driving detectors (steps S3 and S5) for detecting driving on a split μ road which causes different road surface friction coefficients between the left and right wheels. The torque distribution controller controls the torque distribution so that a steering characteristic may be changed to the neutral steering side when driving on the split μ road turning is detected by the split μ road driving detector. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention belongs to the technical field of a torque distribution control device for a vehicle provided with torque distribution control means for controlling torque distribution of at least one of front and rear wheels and left and right wheels.

Conventionally, there is known a mechanical four-wheel drive vehicle that realizes neutral steer during turning by controlling the front-rear distribution at 30:70 to 70:30 and the rear-wheel left-right distribution at 100: 0 to 0: 100 in a stepless manner ( For example, see Patent Document 1). In a vehicle having this structure, the corner turning state is detected by at least one of the steering angle, the differential rotational speed of the left and right front wheels, and the lateral acceleration.
JP 2004-189067 A

  However, with conventional mechanical four-wheel drive vehicles, it is assumed that the road surface friction coefficient with which the left and right wheels contact each other is the same, so that neutral steer can be achieved depending on the vehicle speed and turning radius when entering the corner. Because it controls left and right torque distribution, the cornering force required for tires on the low μ road side cannot be obtained when turning on split μ roads with different road surface friction coefficients on the left and right wheels, and the target neutral steer cannot be achieved. was there.

  For example, when entering a split μ road corner where the turning outer wheel side is a low μ road and the turning inner wheel side is a high μ road, the cornering force of the tire on the turning outer wheel side becomes smaller than the cornering force of the tire on the turning inner wheel side, and the steering characteristic As for, it tends to be understeer.

  The present invention has been made paying attention to the above problem, and an object of the present invention is to provide a vehicle torque distribution control device capable of obtaining high turning performance by realizing neutral steering even during split μ road turning. .

In order to achieve the above object, in the present invention, in a vehicle provided with torque distribution control means for controlling torque distribution of at least one of front and rear wheels and left and right wheels,
A split μ road turning detection means for detecting split μ road turning with a difference in coefficient of friction between the left and right wheels is provided,
The torque distribution control means controls the torque distribution so that the steering characteristic is changed to the neutral steer side when the split μ road turning detection is detected by the split μ road turning detection means.

  Therefore, in the vehicle torque distribution control apparatus according to the present invention, the torque distribution control means is configured to change the steering characteristic to the neutral steer side when the split μ road turning detection is detected by the split μ road turning detection means. Distribution is controlled. For example, when the outer wheel side is traveling on a split μ road having a low μ, it is possible to prevent the vehicle from being understeered by generating a yaw moment on the oversteer side by torque distribution control. As a result, high turning performance can be obtained by realizing neutral steer even when the vehicle is turning on a split μ road.

  Hereinafter, the best mode for carrying out a vehicle torque distribution control apparatus according to the present invention will be described based on a first embodiment shown in the drawings.

First, the configuration will be described.
FIG. 1 is an overall system diagram showing a hybrid four-wheel drive vehicle to which the torque distribution control device of Embodiment 1 is applied.
As shown in FIG. 1, the hybrid four-wheel drive vehicle of Embodiment 1 includes a CPU 101, an auxiliary battery 102, a high-power battery 301, an FR inverter 302, a first motor 303, a generator 304, and an engine 305. , Power split mechanism 306, RR inverter 307, second motor 308, third motor 309, accelerator sensor 401, brake sensor 402, DC / DC converter 403, steering angle sensor 404, GPS 405 A wheel speed sensor 406, and a road surface μ estimation device 407.

The CPU 101 monitors the high-power battery 301, calculates the input / output possible electric energy according to the SOC, temperature, and deterioration state, and controls the FR inverter 302 based on this, thereby the first motor 303 (front drive) And the generator 304 are operated, and the engine 305 is controlled. In addition, by controlling the RR inverter 307, the second motor 308 (for the right rear drive) and the third motor 309 (for the left rear drive) are operated to control the torque distribution control of the left and right rear wheels to achieve neutral steering. Do.
Further, the steering angle is detected using the steering angle sensor 404, the vehicle speed is detected using the wheel speed sensor 406 (vehicle speed detection means), and the turning radius of the corner on the traveling course is detected using the GPS 405 (turning) Radius detection means).
In addition, the ground road surface μ of each of the four wheels is estimated using the road surface μ estimation device 407, and it is determined that the vehicle has entered the split μ road surface corner where the road surface μ of the left and right wheels is different. Using the gap, the torque distribution to the second motor 308 and the third motor 309 is controlled to improve the turning performance.

  The auxiliary battery 102 serves to provide an operating power source for the CPU 101. In this system, power is supplied by a DC / DC converter 403 that uses a high-power battery 301 as a power source.

  The high-power battery 301 assists vehicle travel by supplying electric power to the first motor 303 via the FR inverter 302, and the electric power generated by the first motor 303 being regenerated and the generator 304 are It plays a role of collecting the generated power via the FR inverter 302. In addition, when the second motor 308 and the third motor 309 are powered, the vehicle is assisted by supplying electric power via the RR inverter 307, and the second motor 308 and the third motor 309 generate power. In this case, it also has a role of collecting power via the RR inverter 307.

  The FR inverter 302 is directly controlled by the CPU 101. The electric energy of the high-power battery 301 is supplied to the first motor 303 according to the generated torque and the rotational speed of the engine 305, and the electric energy generated by operating the generator 304 is returned to the high-power battery 301. The first motor 303, the generator 304, and the engine 305 are directly connected to the planetary gear mechanism (incorporated in the power split mechanism 306). It cannot be activated.

  The first motor 303 is for front drive and generates drive torque independently when the vehicle speed is low. Further, when the vehicle speed is high, the driving torque of the engine 305 is assisted. Further, when decelerating, it generates electric energy by generating power (regenerative action), and has the role of returning it to the high-power battery 301 via the FR inverter 302. Further, the control is applied with the motor rotation speed = vehicle speed.

  The generator 304 basically has no starter in a hybrid electric vehicle. At the start of the vehicle to which this system is applied, power is supplied from the high-power battery 301 and the engine 305 is started by operating as a motor. During normal travel, electric energy is generated (power generation) by balancing the first motor 303 and the engine 305 and is returned to the high-power battery 301. Sometimes, it is possible to cope with rapid acceleration by supplying the first motor 303 directly.

  The engine 305 is directly controlled by the CPU 101. Specifically, when the vehicle speed is high, torque is generated to drive the vehicle.

  The power split mechanism 306 has a planetary gear mechanism, and an engine 305 is directly connected to the carrier, a first motor 303 is connected to the ring gear, and a generator 304 is directly connected to the sun gear. The transmission equivalent of the conventional system is also configured inside.

  The RR inverter 307 is directly controlled by the CPU 101. It plays a role of supplying / recovering the electric energy of the high-power battery 301 in accordance with the generated torque and the rotational speed of the second motor 308.

  The second motor 308 is in charge of right rear driving as a 4WD vehicle during normal traveling, and generates torque in the traveling course increase caused by the inner wheel difference during turning traveling, thereby contributing to improvement in traveling and steering stability.

  The third motor 309 is in charge of left rear drive as a 4WD vehicle during normal travel, and generates torque in the travel course increase caused by the inner wheel difference during turning travel, thereby contributing to improved travel and steering stability.

  The brake sensor 402 transmits to the CPU 101 the brake pedal stroke amount that the driver has depressed when decelerating.

  The DC / DC converter 403 converts the energy from the high voltage battery 301 into 12V and supplies it to the auxiliary battery 102. That is, it has the same function as an alternator in a conventional engine vehicle.

  The steering angle sensor 404 has a function of transmitting a steering angle detected by a driver's steering operation to the CPU 101.

  The GPS (Global Positioning System) 405 extracts the turning radius and gradient of the corner that exists up to the destination, and presents each information to the CPU 101.

  The wheel speed sensor 406 is connected to the front two wheels, and transmits the detected value to the CPU 101 as the wheel speed.

  The road surface μ estimation device 407 estimates the ground road surface μ of each of the four wheels and transmits it to the CPU 101.

  Next, the operation will be described.

[Torque distribution control processing]
FIG. 2 is a flowchart showing the flow of torque distribution control processing executed by the CPU 101 of the first embodiment. Each step will be described below (torque distribution control means).

  In step S1, the rotational speeds of the wheel speed sensor 406 and the second motor 308 and the rotational speed of the third motor 309 are detected, and the average value thereof is used as the vehicle speed data in this control, and the process proceeds to step S2.

  In step S2, following the vehicle speed detection in step S1, the turning radius of each corner on the travel route is confirmed by GPS 405, and the process proceeds to step S3.

  In step S3, following the travel route confirmation in step S2, whether or not the vehicle is turning is determined based on the detected value from the rudder angle sensor 404. If the vehicle is turning, the process proceeds to step S4 and goes straight. If it is running, the process proceeds to step S6.

  In step S4, following the determination during turning traveling in step S3, the road surface μ estimation device 407 confirms the estimated values of the ground road surface μ of the left and right wheels, and the process proceeds to step S5.

In step S5, following the estimation of the ground road surface μ of the left and right wheels in step S4, it is determined whether or not the vehicle is currently traveling on the split road surface μ. If yes, the process proceeds to step S7. The process proceeds to S6.
Here, “split μ road judgment” refers to, for example, the average value of the road surface μ where the left front wheel is in contact with the road surface μ where the left rear wheel is in contact, and the road surface μ where the right front wheel is in contact with the right rear wheel. The difference between the average value of the road surface μ with which the wheel is grounded is defined as a μ gap, and when the absolute value of the μ gap (= | μ gap |) exceeds the split μ road determination threshold μ ₀ , the split μ road (See FIG. 4).

  In step S6, following the determination in step S3 and the determination in step S5 that the vehicle is not in a split μ road corner, normal control (for example, control for realizing neutral steering during turning) is executed, and the process returns to return. To do.

In step S7, following the determination that it is split μ road corner traveling in step S5, the torque distribution control change speed is set based on the vehicle speed obtained in step S1 and the turning radius obtained in step S2. The process proceeds to step S8.
Here, as shown in FIG. 3, the setting of the “torque distribution control change speed” is such that the higher the vehicle speed and the smaller the turning radius, the larger the torque distribution control change speed, and conversely, the lower the vehicle speed, Further, the larger the turning radius, the smaller the torque distribution control change speed.

  In step S8, following the setting of the torque distribution control change speed in step S7, it is determined whether or not there is no braking request from the driver based on the detection value of the brake sensor 402. If Yes, the process proceeds to step S9. In this case, the process proceeds to step S10.

In step S9, following the determination in step S8 that there is no braking request, power / power running or regenerative / power running for the left and right rear wheels, the higher the vehicle speed and the larger the μ gap, the torque to the left and right wheels. Torque distribution control is executed to increase the difference in distribution amount, and the process proceeds to return.
Here, the “difference in torque distribution amount to the left and right wheels” determines, for example, a difference in torque distribution amount proportional to the vehicle speed, and multiplies this by the correction coefficient obtained from the map shown in FIG. 4 and | μ gap |. To calculate. For example, when the correction coefficient is k and the turning outer wheel side is a low μ road, the torque distribution ratio between the turning inner wheel and the turning outer wheel is 1: k (> 1).
In addition, “powering / powering” and “regeneration / powering” can be used separately, for example, in a region where the difference in torque distribution to the left and right wheels is smaller than the set value, select “powering / powering” and In a region where the difference in torque distribution amount is equal to or greater than the set value, “regeneration / power running” is selected which can provide a larger difference in torque distribution amount than “power running / power running”.

In Step S10, following the determination that there is a braking request in Step S8, regeneration / regeneration is performed on the left and right rear wheels. The higher the vehicle speed and the larger the μ gap, the difference in the torque distribution amount to the left and right wheels. Torque distribution control to increase the value is executed, and a return is made.
For example, when the turning outer wheel side is a low μ road, the regenerative braking torque distribution is set so that the regeneration amount of the turning inner wheel is larger than the regeneration amount of the turning outer wheel.

[Torque distribution control function]
As shown in FIG. 5 (a), the torque distribution control according to the first embodiment is illustrated by taking the case of entering a split μ road corner, which is a right turn corner and the outside of the turning center line is a low μ road compared to the inside. The operation will be described.

  First, when the proposed torque distribution control is not applied, as shown in FIG. 5 (b), even if the split μ road is entered at time t1, the torque for the rear left and right wheels is not changed before entering the split μ road. And is continuously applied to the rear left and right wheels with the same torque value (positive torque). For this reason, the cornering force required for the tire on the turning inner wheel side is obtained, but the cornering force required for the tire on the turning outer wheel side cannot be obtained, and as a trace situation with respect to the target turning locus, the cornering force on the left and right wheels is Due to the difference, an understeer tendency that gradually bulges outward from the target turning trajectory is shown.

  On the other hand, in the first embodiment, when entering the split μ road corner, when braking is not performed, and when both the left and right rear wheels perform torque distribution control in a power running pattern, in the flowchart of FIG. , Step S1, Step S2, Step S3, Step S4, Step S5, Step S7, Step S8, and Step S9. The torque distribution control change speed is set based on the vehicle speed and the turning radius in Step S7. The difference in torque distribution amount to the left and right rear wheels is set according to the vehicle speed and the absolute value of the μ gap.

  Therefore, as shown in FIG. 6, when the split μ road determination is made at time t1, the left wheel torque out of the torque for the rear left and right wheels is a power running (positive torque) with the same torque value as before entering the split μ road. The right wheel torque is continuously applied, and is given by the power running (positive torque) based on the torque value that decreases with the torque distribution control change speed set from the torque value before entering the split μ road. When the torque distribution amount difference between the left and right rear wheels set at time t2 is reached, the right wheel torque maintains the power running torque value at that time. For this reason, the understeer moment acting on the vehicle due to the difference in tire cornering force between the turning inner and outer wheels is canceled by the oversteer moment acting around the center of gravity of the vehicle due to the drive torque difference between the left and right rear wheels. Neutral steer that follows the target turning trajectory with understeer tendency suppressed. Note that the pattern for performing torque distribution control by powering both the left and right rear wheels is effective when, for example, the vehicle speed is low, the μ gap has a small absolute value, and the difference in torque distribution to the left and right rear wheels is small. It is.

  Further, in the first embodiment, when entering the split μ road corner, without brake braking, and when performing torque distribution control with a power running on one of the left and right rear wheels and a regeneration pattern on the other, In the flowchart of FIG. 2, the flow proceeds from step S1, step S2, step S3, step S4, step S5, step S7, step S8, and step S9. In step S7, the torque distribution control change speed is determined by the vehicle speed and the turning radius. In step S9, the difference in torque distribution amount to the left and right rear wheels is set according to the vehicle speed and the absolute value of the μ gap.

  Therefore, as shown in FIG. 7, when the split μ road determination is made at time t1, the left wheel torque out of the torque for the rear left and right wheels is a power running (positive torque) with the same torque value as before entering the split μ road. The right wheel torque is continuously applied, and is given by regeneration (negative torque) based on the torque value that decreases with the torque distribution control change speed set from the torque value before entering the split μ road. When the torque distribution amount difference between the left and right rear wheels set at time t2 is reached, the right wheel torque is maintained at the regenerative torque value at that time. For this reason, the understeer moment acting on the vehicle due to the difference in tire cornering force between the turning inner and outer wheels is canceled by the oversteer moment acting around the center of gravity of the vehicle due to the difference between the driving torque and braking torque of the left and right rear wheels, and the trace with respect to the target turning trajectory The situation shows a neutral steer where the understeer tendency is suppressed and follows the target turning trajectory. The pattern for performing torque distribution control by powering one of the left and right rear wheels and regenerating the other is, for example, a high vehicle speed and a large absolute value of the μ gap, and the amount of torque distribution to the left and right rear wheels. This is effective when the difference is large.

  Further, in the first embodiment, when entering the split μ road corner, with brake braking, and when performing torque distribution control in a regeneration pattern for both the left and right rear wheels, in the flowchart of FIG. The flow proceeds from S1, Step S2, Step S3, Step S4, Step S5, Step S7, Step S8, and Step S10. In Step S7, the torque distribution control change speed is set by the vehicle speed and the turning radius. In Step S10, The difference in the amount of regenerative torque distribution to the left and right rear wheels is set according to the vehicle speed and the absolute value of the μ gap.

  Therefore, as shown in FIG. 8, when the brake operation is performed at time t1, the torque for the rear left and right wheels is changed from powering to regeneration, and when the split μ road determination is made at time t2, the setting is made. The torque distribution control speed decreases (the change speed of the right wheel is greater than that of the left wheel), and shifts from power running to regeneration (negative torque). When the difference in torque distribution amount between the left and right rear wheels set at time t3 (the right wheel torque is more negative than the left wheel torque), the regenerative torque value at that time is maintained. For this reason, the understeer moment acting on the vehicle due to the difference in tire cornering force between the turning inner and outer wheels is canceled out by the oversteer moment acting around the center of gravity of the vehicle due to the braking torque difference between the left and right rear wheels. Neutral steer that follows the target turning trajectory with understeer tendency suppressed. In addition, the vehicle is decelerated by the regenerative braking of the left and right rear wheels in response to the braking request.

Next, the effect will be described.
In the vehicle torque distribution control apparatus according to the first embodiment, the following effects can be obtained.

  (1) Split μ road turning that detects split μ road turning traveling in which there is a difference in road surface friction coefficient between left and right wheels in a vehicle equipped with torque distribution control means for controlling torque distribution of at least one of the front and rear wheels and the left and right wheels Travel detection means (step S3, step S5) is provided, and the torque distribution control means distributes the torque so that the steering characteristic is changed to the neutral steer side when the split μ road turning detection is detected by the split μ road turning detection means. Therefore, even during split μ road turning, high turning performance can be obtained by realizing neutral steer.

  (2) A vehicle speed detecting means for detecting the vehicle speed and a μ gap detecting means for detecting a μ gap, which is a difference in road surface friction coefficient between the left and right wheels, are provided, and the torque distribution control means increases the vehicle speed. In addition, the larger the μ gap, the larger the difference in torque distribution between the left and right wheels, so the higher the vehicle speed and the larger the μ gap, the stronger the degree of understeer and oversteer of the steer characteristics. Accordingly, understeer and oversteer can be prevented by the optimum moment amount for obtaining neutral steer regardless of the vehicle speed and μ gap.

  (3) A vehicle speed detecting means for detecting the vehicle speed and a turning radius detecting means for detecting the turning radius are provided, and the torque distribution control means changes the torque distribution control as the vehicle speed is higher and the turning radius is smaller. In order to increase speed, the higher the vehicle speed and the smaller the turning radius, the steer characteristic shifts to an understeer tendency or an oversteer tendency with a sharp change, regardless of whether the vehicle speed is high or low or the turning radius is large or small. It is possible to prevent an understeering tendency or an oversteering tendency due to an optimum response speed.

  (4) The torque distribution control means controls the amount of drive torque distributed to the left and right wheels. For example, when entering the split μ road corner at a low speed or entering the split μ road corner with a large turning radius. Thus, when the steering characteristic becomes a weak understeer tendency or a weak oversteer tendency, a difference in torque distribution between the left and right wheels that cancels out a small moment with good response can be obtained.

  (5) The torque distribution control means controls the distribution amount of driving torque to one of the left and right wheels and the distribution amount of braking torque to the other, for example, when entering the split μ road corner at high speed Large left and right wheel torque distribution required to cancel out a large moment when the steering characteristic becomes a strong understeer tendency or a strong oversteer tendency when entering a tight corner of a split μ road with a small turning radius, etc. A quantity difference can be made.

  (6) The torque distribution control means controls the amount of braking torque distributed to the left and right wheels. When a braking request is made during split μ road turning, the vehicle is decelerated in response to the braking request and simultaneously steered. It is possible to prevent the characteristic from becoming an understeer tendency or an oversteer tendency.

  (7) The left and right wheels are independently driven by two motors, and the torque distribution control means obtains the drive torque distribution amount by motor power running and the braking torque distribution amount by motor regeneration. The torque distribution control to the wheels can be executed with high response, and the energy efficiency can be improved by performing the regenerative operation.

  (8) The vehicle includes an engine 305 and a first motor 303 that drive one of the front and rear wheels, and a second motor that independently drives the left and right wheels of the other auxiliary driving wheel of the front and rear wheels. 308 and a third motor 309, and the torque distribution control means is configured to detect the split μ road turning travel by the split μ road turning travel detecting means when the second motor 308 and the third motor 309 are detected. Since the output of the third motor 309 is controlled, torque split optimization control can be executed by the motor output control with high response during split μ road turning, effectively preventing understeering and oversteering, and energy efficiency Can be achieved.

  The vehicle torque distribution control device according to the present invention has been described based on the first embodiment. However, the specific configuration is not limited to the first embodiment, and the claims relate to each claim. Design changes and additions are allowed without departing from the scope of the invention.

  In the first embodiment, as the torque distribution control means, an example in which only the left and right wheel torque distribution control is performed is shown. However, the torque distribution control unit may perform only the front and rear wheel torque distribution control or may perform both the front and rear wheel and left and right wheel torque distribution control. Applicable. Incidentally, in the case of front and rear wheel torque distribution control, the steering performance tends to be understeered by increasing the front wheel torque distribution over the rear wheel torque distribution, and conversely, the steering performance is overrun by increasing the rear wheel torque distribution over the front wheel torque distribution. Steer tendency. In addition, in the case of left and right wheel torque distribution control, the steer performance tends to be under-steered by increasing the inner torque distribution of the turning inner wheel torque distribution than the outer torque distribution of the outer turning wheel. Tends to oversteer.

  In the first embodiment, as a torque distribution control means, a preferred example is shown in which the torque difference between the left and right wheels is determined by the absolute value of the vehicle speed and the μ gap, and the torque distribution control change speed is determined by the vehicle speed and the turning radius, as the split μ road turning. However, the torque difference between the left and right wheels and the torque distribution control change speed may be given by a predetermined fixed value. In short, when the split μ road turning detection is detected by the split μ road turning detection means, the torque distribution control means changes the steering characteristic to the neutral steer side (= direction to reduce the understeer tendency or oversteer tendency). Any device that controls the above is included in the present invention.

  In the first embodiment, the driving torque is obtained by the power running operation of the motor and the braking torque is obtained by the regenerative operation of the motor. However, the driving torque may be obtained by the engine, and the braking torque may be obtained by the hydraulic brake or the motor. It may be obtained by a brake or the like.

  In the first embodiment, the torque distribution control device for the front four-wheel drive-based hybrid four-wheel drive vehicle is shown, but the present invention can also be applied to a rear-wheel drive-based hybrid four-wheel drive vehicle. Further, the present invention can be applied not only to a hybrid four-wheel drive vehicle equipped with an engine and a motor but also to a four-wheel drive vehicle driven by a motor or engine. Further, in the first embodiment, the example in which the motor output of the auxiliary driving wheel is directly controlled as the front and rear wheel torque distribution control means has been shown. However, as described in the prior art, a transfer clutch or differential limiter is included in the driving system. The present invention can also be applied to a device that includes a clutch or the like and controls torque distribution by controlling the clutch engaging force.

1 is an overall system diagram showing a hybrid four-wheel drive vehicle to which a torque distribution control device of Embodiment 1 is applied. 3 is a flowchart illustrating a flow of torque distribution control processing executed by a CPU according to the first embodiment. It is a figure which shows an example of the torque distribution control change speed map by the vehicle speed and turning radius which are used by the torque distribution control of Example 1. FIG. It is a figure which shows an example of the torque distribution amount correction coefficient map by (micro | micron | mu) gap amount used by the torque distribution control of Example 1. FIG. Figure showing the right turn corner and the entrance to the split μ road corner where the outside of the turning center line is a low μ road compared to the inside and the split μ, left wheel torque, right wheel torque, It is a time chart which shows each characteristic of a trace condition and brake ON / OFF. 6 is a time chart showing characteristics of split μ, left wheel torque, right wheel torque, trace status, and brake ON / OFF when the torque distribution control of the first embodiment is applied to both the left and right wheels by powering. 4 is a time chart showing characteristics of split μ, left wheel torque, right wheel torque, trace status, and brake ON / OFF when the torque distribution control of the first embodiment is applied by powering one of the left and right wheels and regenerating the other. . 6 is a time chart showing characteristics of split μ, left wheel torque, right wheel torque, trace status, and brake ON / OFF when the torque distribution control of the first embodiment is applied to both the left and right wheels by regeneration.

Explanation of symbols

101 CPU
102 Auxiliary battery
301 Heavy battery
302 FR inverter
303 1st motor
304 generator
305 engine
306 Power split mechanism
307 Inverter for RR
308 Second motor
309 Third motor
401 Accelerator sensor
402 Brake sensor
403 DC / DC converter
404 Rudder angle sensor
405 GPS
406 Wheel speed sensor
407 Road μ estimation device

Claims (8)

In a vehicle provided with torque distribution control means for controlling torque distribution of at least one of the front and rear wheels and the left and right wheels,
A split μ road turning detection means for detecting split μ road turning with a difference in coefficient of friction between the left and right wheels is provided,
The torque distribution control means controls the torque distribution so that the steering characteristic is changed to the neutral steer side when the split μ road turning detection is detected by the split μ road turning detection means. apparatus. In the vehicle torque distribution control device according to claim 1,
Vehicle speed detection means for detecting the vehicle speed;
A μ gap detecting means for detecting a μ gap, which is a difference in friction coefficient of the road surface on which the left and right wheels contact each other, and
The vehicle torque distribution control device is characterized in that the torque distribution control means sets a larger difference in torque distribution amounts to the left and right wheels as the vehicle speed is higher and the μ gap is larger. In the torque distribution control device for a vehicle according to claim 1 or 2,
Vehicle speed detection means for detecting the vehicle speed;
A turning radius detecting means for detecting a turning radius;
The torque distribution control device according to claim 1, wherein the torque distribution control means increases the torque distribution control change speed as the vehicle speed is higher and the turning radius is smaller. The vehicle torque distribution control device according to any one of claims 1 to 3,
The torque distribution control means controls the amount of drive torque distributed to the left and right wheels. The vehicle torque distribution control device according to any one of claims 1 to 3,
The torque distribution control means controls the distribution amount of driving torque to one of the left and right wheels and the distribution amount of braking torque to the other of the left and right wheels. The vehicle torque distribution control device according to any one of claims 1 to 3,
The torque distribution control means for controlling the distribution of braking torque to the left and right wheels. The torque distribution control device for a vehicle according to any one of claims 1 to 6,
It has a drive system that drives the left and right wheels independently by two motors,
The vehicle torque distribution control device, wherein the torque distribution control means obtains a drive torque distribution amount by motor power running and a braking torque distribution amount by motor regeneration. The torque distribution control device for a vehicle according to any one of claims 1 to 7,
The vehicle includes an engine and a first motor that drive one of the front and rear wheels, and a second motor and a third motor that independently drive the left and right wheels of the other auxiliary driving wheel of the front and rear wheels, respectively. Is a hybrid four-wheel drive vehicle equipped with
The torque distribution control means controls the output of the second motor and the third motor when the split μ road turning detection is detected by the split μ road turning detection means.

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