JP2006217711A - Vehicle controller of electric automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle controller of an electric automobile in which the comfortableness of an occupant can be enhanced by controlling the driving force of a vehicle while ensuring traveling stability thereby favorably suppressing variation in a body posture. <P>SOLUTION: In a vehicle (1) where an outer rotor type drive motor (4) is provided in each wheel (2), the driving force of the right front wheel (2FR) is increased independently when the right front portion of a body ascends and the driving force of the right front wheel is decreased independently when the right front portion of the body descends. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle control device for an electric vehicle, and more particularly to a technique for suppressing a change in vehicle attitude.

The posture of the vehicle body changes depending on the traveling state and the road surface state. For example, when acceleration or deceleration is performed, so-called pitching, which is a vertical change in the front-rear direction of the vehicle body, occurs, and when turning, so-called rolling, which is a vertical change in the left-right direction of the vehicle body, occurs. Further, a part of the vehicle body may rise or fall due to road surface unevenness.
In order to suppress such a change in vehicle body posture, the vehicle is provided with a suspension device (suspension), a shock absorber (damper), and the like.

Although the ride comfort and handling stability of the vehicle are determined by the settings of these suspensions and dampers, it is difficult to achieve both ride comfort and handling stability.
Therefore, a technology has been developed to control the vehicle body posture by controlling the driving force of the vehicle to complement the functions of the suspension and the damper.
For example, when the front wheel part (front) of the vehicle body is raised, the moment in the direction of raising the front due to the reaction force from the road surface is reduced by reducing the output torque of the vehicle, and when the front is lowered, There is a technique for increasing the moment in the direction of raising the front due to the reaction force from the road surface applied to the drive wheels by increasing the output torque of the vehicle and suppressing the pitching of the vehicle (see Patent Document 1).
JP 62-12305 A

However, in the technique disclosed in Patent Document 1, since the overall output torque is reduced during acceleration in order to suppress the pitching of the vehicle body, the driving force necessary for acceleration cannot be obtained sufficiently, and the entire output torque during deceleration is not obtained. Since the output torque is increased, the braking force necessary for deceleration may not be obtained sufficiently, which is not preferable.
As described above, in Patent Document 1, the overall output torque is controlled and the reaction force from the road surface is increased or decreased to suppress the pitching of the vehicle, so that the running stability of the vehicle is impaired. There's a problem.

Further, in Patent Document 1, there is a problem that it is not possible to control the change in the vehicle body posture caused by road surface unevenness.
Furthermore, referring now to FIG. 4, a schematic diagram illustrating the anti-squat angle in a typical vehicle is shown. As shown in the figure, in the general vehicle configured to transmit the driving force generated from the motor or the internal combustion engine from the drive shaft 100 to the driving wheel 102 including the above-mentioned Patent Document 1, the mounting position of the lower arm 104 and the suspension A line L1 ′ drawn from the instantaneous rotation center O ′ determined by the mounting angle 106 to an action point B (center of the drive wheel 102 connected to the drive shaft 100) for transmitting force from the drive wheel 102 to the vehicle body; The angle βf with respect to the horizontal line L2 ′ from the action point B was relatively small.

The angle is an anti-squat angle that affects the control width of the anti-squat generated by the driving force with respect to the so-called squat phenomenon of the vehicle, which is the vertical displacement of the vehicle body. It becomes easy to obtain an effect.
However, it is difficult for a conventional vehicle to take a large anti-squat angle, and the effect of anti-squat is not obtained so much.

  The present invention has been made to solve the above-described problems, and the object of the present invention is to satisfactorily suppress changes in vehicle body posture by controlling the driving force of the vehicle while ensuring traveling stability. Another object of the present invention is to provide a vehicle control device for an electric vehicle that can improve the ride comfort of the occupant.

  In order to achieve the above object, in the vehicle control device for an electric vehicle according to claim 1, a traveling drive motor provided on each of the front wheel and the rear wheel of the vehicle for driving the wheel, and the vehicle body of the vehicle A vehicle body posture displacement detecting means for detecting posture displacement, and a driving force control means for controlling the driving force of the wheel driving drive motor according to the vehicle body posture displacement detected by the vehicle body posture displacement detecting means. It is characterized by that.

Thus, in an in-wheel motor electric vehicle equipped with a driving motor for each wheel, the vehicle body posture change is controlled by independently controlling the driving force of each wheel according to the vehicle body posture displacement of the electric vehicle. Suppress.
In the vehicle control apparatus for an electric vehicle according to claim 2, the vehicle body posture displacement detecting means is provided at each of a right front portion, a left front portion, a right rear portion, and a left rear portion of the vehicle body, and the driving force control means is a right front portion or a left front portion. When the vehicle body posture displacement detecting means detects an upward displacement, the driving force of the driving motor provided on the right front wheel or the left front wheel is increased, respectively, and the vehicle body posture of the right front portion or the left front portion is increased. When the displacement detecting means detects a downward displacement, the driving force of the driving motor provided on the right front wheel or the left front wheel is decreased, respectively, and the vehicle body posture displacement detecting means at the right rear or left rear is raised. When the displacement in the direction is detected, the driving force of the driving motor provided on the right rear wheel or the left rear wheel is decreased, respectively, and the vehicle body posture displacement detection means at the right rear portion or the left rear portion is displaced downward. The When you issue is characterized by increasing the respective driving force of the traveling drive motor provided on the right rear wheel or the left rear wheel.

As a result, when the right front or left front is raised, the driving force of the right front wheel or left front wheel is increased, when it is lowered, the driving force is decreased, and when the right rear or left rear is raised, the right rear wheel Alternatively, the driving force of the left rear wheel is decreased, and when it is lowered, the driving force is increased.
The vehicle control apparatus for an electric vehicle according to claim 3 is characterized in that the driving force to be increased or decreased by the driving force control means is limited within a predetermined range.

  Thus, the driving force used for suppressing the vehicle body posture change is limited within a predetermined range.

According to the vehicle control apparatus for an electric vehicle of claim 1 of the present invention using the above means, the electric vehicle of the in-wheel motor can obtain a wide control width of the anti-squat because the anti-squat angle is large. Further, by providing an in-wheel motor for each wheel, the driving force can be controlled independently for each wheel.
Accordingly, by independently controlling the driving force of the corresponding wheel according to the change in the vehicle body posture of the vehicle, the vehicle body posture change can be sufficiently suppressed, and the riding comfort of the vehicle can be improved. .

According to the vehicle control device for an electric vehicle of the second aspect, by controlling the driving force of each wheel, it is possible to generate a rising force and a lowering force in each part of the vehicle body and suppress a change in the posture of the vehicle body. .
According to the vehicle control device for an electric vehicle of claim 3, by limiting the driving force used for suppressing the change in the vehicle body posture, the driving force necessary for traveling of the vehicle can be ensured, and the traveling stability of the vehicle Can be maintained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Referring to FIG. 1, there is shown a schematic configuration diagram of an electric vehicle equipped with a vehicle control device according to the present invention. With reference to FIG. 2, the anti-squat angle of an electric vehicle equipped with a vehicle control device according to the present invention is shown. A schematic diagram is shown.
As shown in FIG. 1, a vehicle 1 is a four-wheel drive electric vehicle in which each wheel 2 is provided with a drive motor 4 (running drive motor) independently.

Specifically, a right front drive motor 4FR is provided in the right front wheel 2FR, a left front drive motor 4FL in the left front wheel 2FL, a right rear drive motor 4RR in the right rear wheel 2RR, and a left rear drive motor 4RL in the left rear wheel 2RL. Yes.
These drive motors 4 are so-called outer rotor type in- hibits composed of a rotor 4a provided on the inner periphery of the wheel 2 and a stator 4b fixed to the vehicle body via a knuckle (not shown). It is a wheel motor.

  In the vehicle 1 equipped with such an outer rotor type in-wheel motor, as shown in FIG. 2, the instantaneous rotation center O determined by the mounting position of the lower arm 6 and the mounting angle of the suspension 8 is the same as the conventional one. A portion for transmitting force from 2 to the vehicle body is a stator 4 b portion of the drive motor 4. Here, since the portion of the stator 4b can be approximated to a contact point between the wheel 2 and the ground, the contact point can be regarded as an action point A, and from this, a line L1 drawn from the action point A to the instantaneous rotation center O. And the anti-squat angle αf, which is an angle between the operating point A and the horizontal line L2, is larger than the conventional one.

As a result, the outer rotor type in-wheel motor can have a large control width of the anti-squat.
The driving force of each driving motor 4 depends on the electric power supplied from the traveling battery 10 provided in the vehicle 1 via the inverters 12FR, 12FL, 12RR, 12RL corresponding to the driving motor 4. appear.

Further, the vehicle 1 is provided with an APS (accelerator position sensor) 14 that detects an accelerator operation amount, a BPS (brake position sensor) 16 that detects a brake operation amount, and a handle angle sensor 18 that detects a handle angle.
In addition, vehicle height sensors 22FR, 22FL, 22RR, and 22RL (also referred to as vehicle height sensors 22) are provided in the vicinity of each wheel 2 of the vehicle body. Vertical displacement from the reference position at the right front, left front, right rear, and left rear is detected (vehicle body posture detection means). Here, the reference position is based on the vehicle body posture when the vehicle 1 is stopped, for example.

Further, the vehicle 1 is equipped with a TCU (torque control unit) 30 (driving force control means) for controlling the driving force generated by each driving motor 4, and the TCU 30 includes the inverter 12, the APS 14, It is connected to various devices such as the BPS 16, the handle angle sensor 18, and the vehicle height sensors 22.
The operation of the vehicle control apparatus for an electric vehicle according to the present invention configured as described above will be described below.

Referring to FIG. 3, a driving force control routine of each driving motor 4 executed in the TCU 30 is shown in a flowchart, and will be described below based on the flowchart.
Note that the driving force that is increased or decreased by the driving force control is limited to a predetermined value (for example, within 20% of the driving force necessary for traveling) in order to ensure the driving force necessary for traveling of the vehicle 1. ing. Further, when the driving force is reduced, the reduced result may be a negative driving force.

First, in step S10, it is determined from the vehicle height sensor 22FR provided at the right front portion of the vehicle body whether the right front portion is displaced upward, that is, whether it is in the raised state. If the determination result is true (Yes), the process proceeds to step S11.
In step S11, the driving force of the drive motor 4FR provided in the right front wheel 2FR is increased, and the process proceeds to step S20.

On the other hand, if the determination result of step S10 is false (No), the process proceeds to step S12.
In step S12, it is determined from the vehicle height sensor 22FR whether the right front portion is displaced downward, that is, whether it is in a lowered state. If the determination result is true (Yes), the process proceeds to step S13.
In step S13, the driving force of the drive motor 4FR provided in the right front wheel 2FR is decreased, and the process proceeds to step S20.

If the determination result in step S12 is false (No), that is, if the right front portion is not displaced, the process proceeds to the next step S20 as it is.
In step S20, it is determined from the vehicle height sensor 22FL provided at the left front portion of the vehicle body whether the left front portion is displaced upward, that is, whether it is in the raised state. If the determination result is true (Yes), the process proceeds to step S21.

In step S21, the driving force of the drive motor 4FL provided in the left front wheel 2FL is increased, and the process proceeds to step S30.
On the other hand, if the determination result of step S20 is false (No), the process proceeds to step S22.
In step S22, it is determined from the vehicle height sensor 22FL whether the left front portion is displaced downward, that is, whether it is in a lowered state. If the determination result is true (Yes), the process proceeds to step S23.

In step S23, the driving force of the drive motor 4FL provided in the left front wheel 2FL is decreased, and the process proceeds to step S30.
If the determination result in step S22 is false (No), that is, if the left front portion is not displaced, the process proceeds to the next step S30 as it is.
In step S30, it is determined from the vehicle height sensor 22RR provided at the right rear portion of the vehicle body whether the right rear portion is displaced upward, that is, whether it is in the raised state. If the determination result is true (Yes), the process proceeds to step S31.

In step S31, the driving force of the drive motor 4RR provided in the right rear wheel 2RR is decreased, and the process proceeds to step S40.
On the other hand, if the determination result of step S30 is false (No), the process proceeds to step S32.
In step S32, it is determined from the vehicle height sensor 22RR whether the right rear part is displaced downward, that is, whether it is in a lowered state. If the determination result is true (Yes), the process proceeds to step S33.

In step S33, the driving force of the drive motor 4RR provided in the right rear wheel 2RR is increased, and the process proceeds to step S40.
If the determination result in step S32 is false (No), that is, if the right rear portion is not displaced, the process proceeds to the next step S40 as it is.
In step S40, it is determined from the vehicle height sensor 22RL provided at the left rear part of the vehicle body whether the left rear part is displaced upward, that is, whether it is in an ascending state. If the determination result is true (Yes), the process proceeds to step S41.

In step S41, the driving force of the drive motor 4RL provided in the left rear wheel 2RL is decreased, and the routine is exited.
On the other hand, if the determination result of step S40 is false (No), the process proceeds to step S42.
In step S42, it is determined from the vehicle height sensor 22RL whether the left rear portion is displaced downward, that is, whether it is in a lowered state. If the determination result is true (Yes), the process proceeds to step S43.

In step S43, the driving force of the driving motor 4RL provided in the left rear wheel 2RL is increased, and the routine is exited.
If the determination result in step S42 is false (No), that is, if the left rear portion is not displaced, the routine is exited as it is.
As described above, when the right front part and the left front part of the vehicle body are raised, the driving force of the right front wheel 2FR and the left front wheel 2FL is increased so that the anti-squat is generated by the driving force and acts downward in the vehicle body part. The increase can be suppressed by improving the force. Further, when the right front part and the left front part of the vehicle body are lowered, the anti-squat force can be reduced by reducing the driving force of the right front wheel 2FR and the left front wheel 2FL, whereby the increase can be suppressed.

  In addition, when the right rear part and the left rear part of the vehicle body are lowered, the anti-squat force, which is the upward working force at the rear part of the vehicle body, is improved by increasing the driving force of the right rear wheel 2RR and the left rear wheel 2RL. Lowering can be suppressed. Further, when the right rear portion and the left rear portion of the vehicle body are raised, the lowering can be suppressed by reducing the anti-squat force by reducing the driving force of the right rear wheel and the left rear wheel.

Further, since the vehicle 1 is an outer rotor type four-wheel in-wheel motor electric vehicle, the driving force can be controlled independently for each wheel, and the control range of the anti-squat by the driving force control is large and sufficient. An effect of suppressing vehicle body change can be obtained.
As a result, the riding comfort of the vehicle 1 can be improved.
In addition, the driving force used to suppress the change in the vehicle body posture is limited so as to secure a necessary amount for traveling of the vehicle, so that the traveling of the vehicle 1 is not hindered and the traveling stability of the vehicle 1 is maintained. be able to.

  Here, if the accelerator operation amount, the brake operation amount, and the change amount of the handle angle detected by the APS 14, BPS 16, and the handle angle sensor 18 are equal to or greater than a predetermined value, the degree of change in the posture of the vehicle caused by acceleration / deceleration or turning motion is increased. It is also possible to control the driving force of the driving motor 4 provided on each wheel 2 so as to attenuate. By doing so, the same effect as a general damper can be obtained by controlling the driving force.

Although the description of the embodiment of the vehicle control apparatus for an electric vehicle according to the present invention is finished as above, the embodiment is not limited to the above embodiment.
For example, in the above embodiment, the vertical displacement on the left and right sides of the vehicle body is detected by the vehicle height sensors 22FR, 22FL, 22RR, and 22RL, but any device that can detect the posture displacement of the vehicle body may be used. The displacement of the suspension may be detected.

  Moreover, in the said embodiment, although the attitude | position change degree of the vehicle 1 of the vehicle 1 is detected using APS14, BPS16, the handle | steering-wheel sensor 18, etc., it is not restricted to this, Even if it detects with another apparatus. I do not care.

It is a schematic block diagram of the vehicle provided with the vehicle control apparatus which concerns on this invention. It is a schematic diagram which shows the anti squat angle of the vehicle which concerns on this invention. It is a part of flowchart which shows the driving force control routine of each drive motor performed in TCU in the vehicle control apparatus of the electric vehicle which concerns on this invention. It is a schematic diagram which shows the anti squat angle in a common vehicle.

Explanation of symbols

1 vehicle 2 wheel 4 drive motor (traveling drive motor)
14 APS
16 BPS
18 Handle angle sensor 22 Vehicle height sensor (body posture detection means)
30 TCU (driving force control means)

Claims (3)

A driving motor for driving the wheels provided on the front and rear wheels of the vehicle;
Vehicle body posture displacement detecting means for detecting the vehicle body posture displacement of the vehicle;
Driving force control means for independently controlling the driving force of the wheel driving drive motor according to the vehicle body posture displacement detected by the vehicle body posture displacement detecting means;
A vehicle control device for an electric vehicle, comprising: The vehicle body posture displacement detecting means is provided at each of a right front portion, a left front portion, a right rear portion, and a left rear portion of the vehicle body,
The driving force control means includes
When the vehicle body posture displacement detecting means at the right front part or the left front part detects an upward displacement, the driving force of the traveling drive motor provided on the right front wheel or the left front wheel is increased,
When the vehicle body posture displacement detecting means at the right front part or the left front part detects a downward displacement, the driving force of the driving motor provided on the right front wheel or the left front wheel is decreased, respectively.
When the vehicle body posture displacement detecting means at the right rear part or the left rear part detects an upward displacement, the driving force of the driving motor provided on the right rear wheel or the left rear wheel is reduced, respectively.
When the vehicle body posture displacement detecting means at the right rear part or the left rear part detects a downward displacement, the driving force of the driving motor provided on the right rear wheel or the left rear wheel is increased, respectively. The vehicle control device for an electric vehicle according to claim 1.   3. The vehicle control apparatus for an electric vehicle according to claim 1, wherein the driving force that is increased or decreased by the driving force control means is limited within a predetermined range.

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