WO2013005903A1

WO2013005903A1 - Apparatus for controlling a pitch motion of an in-wheel motor-driven electric vehicle

Info

Publication number: WO2013005903A1
Application number: PCT/KR2011/010104
Authority: WO
Inventors: 김영렬; 왕지남
Original assignee: 주식회사 유디엠텍
Priority date: 2011-07-07
Filing date: 2011-12-26
Publication date: 2013-01-10
Also published as: KR101265053B1; KR20130005867A

Abstract

Provided is an apparatus for controlling a pitch motion of an in-wheel motor-driven electric vehicle. The apparatus for controlling the pitch motion of the in-wheel motor-driven electric vehicle according to the present invention includes a suspension system including a spring extensible or compressible according to a driving force of a corresponding wheel that is rotated depending on the torque of the in-wheel motors of each of the left and right front wheels and left and right rear wheels of an electric vehicle having six wheels or a braking force generated by friction between the corresponding wheel and a road, wherein the driving or braking force is applied to a frame as a component force which restricts a vertical motion of the frame generated by an angle between a virtual link and the road, due to a pitching motion during the driving of the vehicle.

Description

Pitch motion controller of in-wheel motor driven electric vehicle

The present invention relates to a pitch motion control apparatus for an in-wheel motor-driven electric vehicle, and more particularly, to a technology for reducing the forward and backward rotational movement of a vehicle generated during driving of the vehicle through torque control of the in-wheel motor.

In the electric vehicle, the electric drive motor is a device that generates a driving force to rotate the wheel by replacing the engine of the existing internal combustion engine vehicle with its original function. The electric drive motor has the advantage of producing the commanded torque very quickly and accurately as compared to the engine of the internal combustion engine, and in the case of the in-wheel motor in which the electric drive motor is installed in the wheels, each wheel can be independently driven. Thus, the in-wheel motor-driven electric vehicle has excellent controllability and independent driving force of the in-wheel motor. For this reason, in recent years, in-wheel motor-driven electric vehicles have been actively developed and researched on wheel slip control and yaw motion control by turning the vehicle using excellent controllability and independent driving force of the electric drive motor.

However, in the field of in-wheel motor-driven electric vehicles, technology development and research on improving the ride comfort of the occupants have not been made by reducing the pitch movement, which is a rotational movement in the front and rear directions of the vehicle.

A pitch motion control apparatus for an in-wheel motor-driven electric vehicle is proposed, which reduces the pitch movement of the vehicle body to rotate in the front-rear direction by using independent braking force or driving force control characteristics of each wheel of the in-wheel motor.

The pitch motion control apparatus of an in-wheel motor-driven electric vehicle according to an aspect of the present invention, the front wheel and the left and right rear wheels of the six-wheeled electric vehicle, the wheel and the road surface that rotates in accordance with the torque of the in-wheel motor The driving force or braking force of the wheel generated by friction is the angle between the virtual link of the suspension system and the road surface, and it is stretched or compressed as it acts on the body by the component force that hinders the vertical movement of the body due to the pitch movement while driving. It includes a suspension equipped with a spring.

The directions of the braking force or driving force of the left and right front wheels and the left and right rear wheels are the same, and the direction of the braking force or the driving force of the left and right middle wheels of the six-wheeled electric vehicle is opposite to the direction of the braking force or the driving force of the left and right front wheels and the left and right rear wheels. It can have

The sum of the driving force or braking force of all wheels of the six-wheeled electric vehicle generated by friction with the road surface becomes "0", and the driving force of all wheels of the six-wheeled electric vehicle generated by friction with the road surface or The sum of the turning moments produced by the braking force can be "0".

According to another aspect of the present invention, a pitch motion control apparatus for an in-wheel motor-driven electric vehicle includes: a first subtractor configured to output a deviation between a target pitch speed of a driver and a pitch speed of the electric vehicle output from a six-wheeled electric vehicle; A second subtractor outputting a deviation between a target longitudinal speed of a driver and a longitudinal speed of the electric vehicle output from the electric vehicle; A first PI controller configured to proportionally integrate and control a value output from the first subtractor, thereby outputting a component force that hinders vertical movement of the vehicle body; A torque converter for multiplying the component force by the wheel radius of a six-wheeled electric vehicle of the same size and outputting a pitch motion control torque to be applied to the left and right front wheels and the left and right rear wheels for pitch motion control; A second PI controller configured to proportionally integrate a value output from the second subtractor to output a driving torque for following a target longitudinal speed of the driver; A torque forming unit for obtaining torques of all wheels of the six-wheeled electric vehicle by using the pitch movement control torque and the drive torque output from the second PI controller; For each of the left and right front and rear wheels of a six-wheeled electric vehicle, the driving or braking force of the wheel generated by friction between the wheel and the road surface rotating according to the torque of the in-wheel motor is displayed. This suspension angle includes a suspension device having a spring that is extended or compressed by acting on the vehicle body as a component that prevents the vertical movement of the vehicle body due to the pitch movement while driving the vehicle, the torque of the wheel obtained from the torque forming unit An electric vehicle that measures and outputs a pitch speed, a pitch angle, and a longitudinal speed of the electric vehicle being driven by the rotation of the wheel using a pitch speed sensor, a pitch angle sensor, and a speed sensor; And an application unit determining whether the pitch movement control torque is applied to the torque forming unit according to whether the pitch angle and the pitch speed of the electric vehicle coincide with each other.

The target pitch speed of the driver may be set to zero.

The torque of all the wheels can be obtained using the following equation.

[수학식][Equation]

At this time,

Is the pitch motion control torque to be applied to the left and right front wheels and the left and right rear wheels for pitch motion control,

Is the driving torque for following the driver's target longitudinal speed,

Is the torque of the left front wheel,

Is the torque of the right front wheel,

Is the torque of the left middle wheel,

Is the torque of the right middle wheel,

Is the torque of the left rear wheel and

Represents the torque of the right rear wheel.

The applicator may include: a determining unit configured to check whether the pitch angles and pitch speeds of the electric vehicle coincide with each other and to output “1” if they match and output “0” if they do not match; And a multiplier configured to multiply and output an output value of the determination unit and the pitch motion control torque value.

According to the pitch motion control apparatus of an in-wheel motor-driven electric vehicle according to an embodiment of the present invention, by using the independent braking force or driving force control characteristics of the in-wheel motor to reduce the pitch angle accompanying the pitch motion of the vehicle body generated during the driving of the vehicle As a result, the phenomenon of rotational movement in the front-rear direction of the vehicle generated while the vehicle is running can be reduced.

1 is a relationship between the vertical movement of the rear tire road surface ground point and the virtual link of the suspension system.

2 is a view showing the direction and pitching angle of the inertia force during vehicle braking.

3 is a diagram in which a middle wheel generates a braking force or a driving force opposite to a braking force or a driving force of a front and rear wheel in a six-wheeled vehicle to which an embodiment of the present invention is applied;

4 shows an ideal suspension model.

5 shows an actual suspension model.

6 is a view showing a suspension model according to an embodiment of the present invention.

7 is a view showing the configuration of a pitch motion control apparatus for an in-wheel motor-driven electric vehicle according to an embodiment of the present invention.

8 illustrates a road surface profile for vehicle pitch motion simulation.

9 is a view showing a simulation result for a vehicle pitch motion in a time domain.

10 is a diagram showing simulation results for a vehicle pitch motion in a frequency domain.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention; In describing the embodiments of the present invention, when it is determined that detailed descriptions of related known functions or configurations may obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, terms to be described below are terms defined in consideration of functions in the present invention, which may vary according to intention or custom of a user or an operator. Therefore, the definition should be made based on the contents throughout the specification.

The pitch motion control apparatus for an in-wheel motor-driven electric vehicle according to an embodiment of the present invention includes a suspension device that enables vertical motion for each wheel of the left and right front wheels and the left and right rear wheels. By this suspension, the road-grounding center point of the wheel tire can have a vertical movement trajectory of the ground point as shown in FIG. 1 when the wheel is viewed from the side. The up-and-down movement trajectory of this ground point is related to the anti-dive / anti-lift characteristics in the movement of the vehicle, and is moved by the rotation of the virtual link as shown in FIG. And the road surface has a predetermined angle (

)

Let's take a look at this anti-dive / anti-lift feature.

When the vehicle accelerates or decelerates, the body moves in pitch due to the inertia force acting on the center of gravity of the vehicle.

For example, as shown in FIG. 2, when the vehicle decelerates by the braking force, the moment of inertia of the vehicle due to the deceleration acts in the forward direction of the vehicle, resulting in a moment in the direction in which the vehicle body is inclined forward. This increases and the load decreases in the case of the rear wheels, so that the vehicle eventually dives.

At this time, the virtual link of the front wheel suspension and the virtual wheel of the rear wheel suspension receiving the braking force due to the braking force acting on the road surface, respectively, the predetermined first angle formed with the road surface (

) And second angle (

), The component force is generated in the upward direction of the vehicle body by the first angle, and the front wheel suspension spring is extended (stretched) by the component force generated in this upward direction, and the component force is generated downward in the vehicle body by the second angle. The rear wheel suspension spring is compressed by the force generated in the downward direction, thereby reducing the dive phenomenon of the vehicle.

As shown in Figure 2, the instantaneous rotation center of the virtual link of the front wheel suspension (

Instantaneous rotation center of the virtual link of the rear suspension, so that the position of

If the position of the) is designed to be in front of the rear wheels, it can produce a force that interferes with the pitch movement of the body caused by the braking of the vehicle. This component reduces the vertical movement of the body, which is the anti-dive / anti-lift characteristics.

In other words, using the anti-dive / anti-lift characteristics created by the suspension system, the braking force or driving force generated by friction with the road surface of the wheel rotated by the torque of the in-wheel motor is the angle between the virtual link of the suspension device and the road surface. As a result, the spring of the suspension device can be stretched or compressed by acting on the vehicle body by the component force in the vertical direction of the vehicle body.

In this case, when the pitch movement of the vehicle is reduced while driving the vehicle, the braking force or driving force generated on the wheels on the road surface by the torque of the in-wheel motor becomes the same direction in both front and rear wheels, thereby obstructing the original traveling direction of the vehicle. It is not desirable.

In detail, the direction of the component force that prevents the up and down movement of the vehicle body should act in the upper direction of the vehicle body in the left and right front wheels, and in the case of the left and right rear wheels, in the downward direction of the vehicle body. In the direction of the vehicle, the left and right rear wheels should act in the upper direction of the vehicle body.

To this end, the direction of the component force that hinders the vertical movement of the vehicle body to reduce the pitch movement of the vehicle body to rotate in all directions should be in the upward direction in the left and right front wheels, and in the downward direction in the left and right rear wheels, For this purpose, the direction of the braking force or driving force by the torque of the in-wheel motors of the left and right front wheels becomes the braking force, and the direction of the braking force or the driving force by the torque of the in-wheel motors of the left and right rear wheels must also be the braking force.

Similarly, when a pitch motion in which the vehicle body rotates in the rear direction occurs, the direction of the component force hindering the vertical movement of the vehicle body to reduce it should be downward in the left and right front wheels and upward in the left and right rear wheels. For this purpose, the direction of the braking force or driving force by the torque of the in-wheel motors of the left and right front wheels becomes the driving force, and the direction of the braking force or the driving force by the torque of the in-wheel motors of the left and right rear wheels must also be the driving force.

That is, the directions of braking force or driving force of the front and rear wheels for reducing the pitch motion of the vehicle coincide. However, the matching of the direction of braking force or driving force of the front and rear wheels is not preferable because it is to change the magnitude of the braking force or driving force for the vehicle to originally drive desired. Therefore, the control of the braking force or the driving force of the in-wheel motor for reducing the pitch movement of the vehicle is not applicable because it interferes with the original movement of the vehicle.

However, the present invention can reduce the pitch motion of the vehicle by controlling the braking force or the driving force of the in-wheel motor without disturbing the movement of the vehicle in the case of a six-wheel drive vehicle having a left and right front wheel and a left and right rear wheel. .

That is, in order to reduce the pitch movement of the vehicle, the braking force or the driving force in the same direction is generated in the left and right front wheels and the left and right rear wheels of the six-wheel drive vehicle, and in the opposite direction of the left and right front wheels and the left and right rear wheels in the middle wheel of the six-wheel drive vehicle. To generate braking or driving force. That is, the braking force or driving force of the left and right front wheels and the left and right rear wheels and the braking force or driving force of the left and right middle wheels cancel each other, thereby reducing the pitch motion of the vehicle without disturbing the original movement of the vehicle.

In other words, in the case of the six-wheeled vehicle including the left and right middle wheels as illustrated in FIG. 3, the braking force or the driving force of the left and right middle wheels is the direction of the left and right front wheels even when the braking force or the driving force is reduced, respectively, to reduce the pitch movement. And if the offset to occur in the opposite direction to the force of the left and right rear wheels, the sum of their overall braking force or driving force is zero (0) can reduce the pitch motion without disturbing the original running of the vehicle.

In addition, the sum of the turning moments generated by the driving force or the braking force of all the wheels of the six-wheeled vehicle generated by the friction with the road surface may be "0". That is, when the distance from the vehicle center line (not shown) of FIG. 3 to the position where the braking force or driving force of each wheel is applied is t and the braking force or driving force by torque τ _p of the in-wheel motor is Fp, the turning moment is the left front wheel, (Τ _p × t)-(τ _p × t) +2 (τ _p × t) -2 (τ _p × t) + (τ _{p in the} order of right front wheel, left middle wheel, right middle wheel, left rear wheel and right rear wheel × t) - it is a (τ _p × t) is "0".

Referring to FIG. 2 again, a description will be given of the reduction of the pitch motion generated while driving the vehicle.

If the pitch movement as illustrated in FIG. 2 occurs while driving the vehicle, braking force is applied to both the left and right front wheels and the left and right rear wheels. The braking force on the left and right front wheels produces a component force acting upward on the vehicle body by the virtual link formed by the suspension as shown in FIG. 2, and the brake force on the left and right rear wheels creates a component force acting downward on the vehicle body. It acts as a force to reduce the pitch movement.

Means for limiting the vertical movement of the vehicle body in the existing internal combustion engine vehicle is to directly control the force in the vertical direction acting on the vehicle body, for this purpose it is possible to vary the damping coefficient of the damping force of the damper as a suspension element Skyhook control technique is used to determine damping coefficient with variable damper. Let's look at this.

Skyhook control is directly proportional to the speed of the vehicle M by installing a virtual skyhook manual damper on the virtual Inertia Reference and the spring mass M of the vehicle, as shown in FIG. 4. It is a method of generating attenuation force.

However, since this is not possible in practice, the equivalent damping force is generated by using the variable damper of the suspension as shown in FIG.

The equivalent damping coefficient in the actual suspension model can be obtained through Equation 1 below.

Equation 1

At this time,

Is the equivalent damping factor in the actual suspension model,

Is the equivalent damping factor in the ideal suspension model,

Is the vertical velocity of the body (spring weight),

Represents the up-down speed of the wheel (spring lower weight).

In addition, the equivalent damping force in FIG. 5 may be obtained only under the condition shown in Equation 2 below.

Equation 2

At this time, the equivalent damping force

ego

Occurs when all the cases are satisfied, or

ego

This may occur when all of the following conditions are satisfied. That is, an equivalent damping force may occur when the direction of the vehicle's up-down speed and the direction of the vehicle between the vehicle's up-down speed and the wheel's up-and-down speed coincide with each other.

Accordingly, the pitch motion control apparatus of the in-wheel motor-driven electric vehicle according to an embodiment of the present invention, according to the pitch motion to rotate the vehicle body back and forth while the vehicle is running by using the sky hook control method, the left and right front wheels and left and right of the six-wheeled electric vehicle The force generated in the direction of reducing the vertical motion of the electric vehicle body due to the stretching and compression of each suspension spring of the rear wheel is applied to the vehicle body, thereby increasing the vertical movement of the suspension springs of the left and right front wheels and the left and right rear wheels of the electric vehicle. It is possible to reduce the pitch movement of the vehicle body generated while driving the vehicle.

A model of the suspension applied to an embodiment of the present invention is shown in FIG.

As shown in Figure 6, the suspension model according to an embodiment of the present invention, a spring for supporting the wheel 4, the electric vehicle body 1 of the electric vehicle having an in-wheel motor (spring) (2) and a damper (3) for absorbing the vibration in the vertical direction of the electric vehicle body (1). At this time, the wheel 4 is a case in which the left and right front wheels, the left and right middle wheels and the left and right rear wheels of the electric vehicle are modeled and displayed by only one wheel. This is an example, and it is obvious that other embodiments are possible.

The driving force or braking force generated by the friction between the wheel and the road surface rotated by the torque of the in-wheel motor acts on the vehicle body by the component force that hinders the up and down movement of the vehicle body by the angle between the virtual link of the suspension device and the road surface. The spring of the suspension can be stretched or compressed.

At this time, the component force hindering the vertical movement of the body

Becomes a force applied to the vehicle body in order to reduce the movement of the vehicle body in the up and down direction due to the rotation of the vehicle body generated during driving of the electric vehicle in the front-rear direction. As a result, the component force impedes the up and down movement of the vehicle body.

Acts on the vehicle body, the spring of the suspension is stretched or compressed in a direction that obstructs the pitch movement of the vehicle body. As a result, the pitch motion generated while driving the vehicle can be reduced.

And components that interfere with the up and down movement of the body

Is a component that prevents the vertical movement of the vehicle body generated by each of the left and right front wheels of the electric vehicle and the vertical direction of the vehicle body generated by the left and right rear wheels of the electric vehicle. It can be divided into components that interfere with exercise.

The component force hindering the vertical movement of the vehicle body generated by each of the left and right front wheels is the driving force or braking force of each of the left and right front wheels generated by the friction between the road surface and each of the left and right front wheels rotated by the torque of the in-wheel motor. As the angle between each virtual link and the road surface, it acts on the car body by the component force that hinders the up and down movement of the car body, and expresses the force to stretch or compress the spring of each of the left and right front wheel suspensions.

The component force hindering the vertical movement of the vehicle body generated by each of the left and right rear wheels is the driving force or braking force of each of the left and right rear wheels generated by the friction between the road surface and the left and right rear wheels rotated by the torque of the in-wheel motor. As the angle formed by each virtual link and the road surface, it acts on the car body by the component force that hinders the up and down movement of the car body, and expresses the force to stretch or compress the springs of the left and right rear wheel suspensions.

7 is a view showing the configuration of the pitch motion control apparatus of the in-wheel motor-driven electric vehicle according to an embodiment of the present invention.

As shown in FIG. 7, the pitch motion control apparatus of an in-wheel motor-driven electric vehicle according to an exemplary embodiment of the present invention includes a first subtractor 10, a second subtractor 11, a first PI controller 12, and a first subtractor. 2 includes a PI controller 13, a torque converter 14, a torque forming unit 15, a six-wheeled electric vehicle 16, and a torque applying unit including a determination unit 17 and a multiplier 18.

The first subtractor 10 is a target pitch speed of the driver

And pitch speed of the vehicle output from the electric vehicle 16

Output the deviation of. In this case, the target pitch speed of the driver may be “O (Zero)”. This is for the electric vehicle occupant to have a comfortable ride so as not to be affected by the pitch movement.

The second subtractor 11 is the target longitudinal speed of the driver

Speed of the electric vehicle output from the electric vehicle and the electric vehicle 16.

Output the deviation of. At this time, the target longitudinal speed of the driver

Means the electric vehicle speed desired by the driver while driving the electric vehicle. The driver is responsible for the current vehicle speed of the electric vehicle in operation, ie the longitudinal speed of the electric vehicle.

Recognize and maintain the speed of the electric vehicle (vehicle) to accelerate or decelerate. In order to maintain the speed of the electric vehicle, the state of the current accelerator pedal is maintained, the accelerator pedal is further pressed for acceleration, and the deceleration pedal is mainly operated for deceleration. The operation of the driver's acceleration / deceleration pedal is the same as that of increasing or decreasing the torque of the in-wheel motor or the command of the regenerative braking torque, and thus is equivalent to the role of the second PI controller 13 in FIG. 6. Because the PI controller applies the torque applied to the in-wheel motor from the driver's target longitudinal speed and the current electric vehicle's longitudinal speed deviation, that is, drive torque for following the driver's target longitudinal speed.

This is because

The first PI controller 12 proportionally integrates the value output from the first subtractor 10 and outputs a component force that prevents the up and down movement of the vehicle body.

The torque converter 14 multiplies the wheel radius of the six-wheeled electric vehicle of the same size by the component force that hinders the up and down movement of the vehicle body. Pitch motion control torque applied to left and right front wheel and left and right rear wheel

Outputs

The second PI controller 13 proportionally integrates the value output from the second subtractor 11 to drive the target torque to follow the target longitudinal speed of the driver.

Outputs

The torque forming unit 15 is a pitch motion control torque output from the torque converting unit 14.

And drive torque output from the second PI controller 13

Torque of left front wheel

Torque on right front wheel

, Left middle wheel torque

And right middle wheel torque

, Left rear wheel torque

And right rear wheel torque

Obtain

At this time, the torque of the left front wheel, the torque of the right front wheel, the torque of the left middle wheel, the torque of the right middle wheel, the torque of the left rear wheel and the torque of the right rear wheel can be obtained using Equation 3 below.

Equation 3

At this time,

Is the driving torque for following the driver's target longitudinal speed,

Is the torque of the left front wheel,

Is the torque of the right front wheel,

Is the torque of the left middle wheel,

Is the torque of the right middle wheel,

Is the torque of the left rear wheel and

Represents the torque of the right rear wheel. In this case, the torque for reducing the pitch motion of the middle wheel is opposite to that of the front and rear wheels, and has a double value.

The electric vehicle 16 includes six wheels, and the driving force of the wheels generated by friction between the wheels and the road surface which rotates according to the torque of the in-wheel motor among the left and right front wheels and the left and right rear wheels of the six wheels. Or a suspension provided with a spring that extends or compresses as the braking force acts on the vehicle body by a component force that prevents the vertical movement of the vehicle body due to the pitch movement while driving the vehicle as much as the angle between the virtual link of the suspension system and the road surface. . At this time, the directions of braking force or driving force of the left and right front wheels and the left and right rear wheels are the same, and the direction of the braking force or driving force of the left and right middle wheels of the six-wheeled electric vehicle is opposite to the direction of the braking force or the driving force of the left and right front wheels and the left and right rear wheels, and the size of the driving force is doubled. Can have In addition, the sum of driving force or braking force of all wheels of the six-wheeled electric vehicle generated by friction with the road surface becomes "0", and the driving force or braking force of all wheels of the six-wheeled electric vehicle generated by friction with the road surface is generated. The turn moment sum can be "0".

In addition, the electric vehicle 16 may calculate the pitch speed, the pitch angle, and the longitudinal speed of the electric vehicle being driven by the rotation of each wheel according to the respective torque values obtained by the torque forming unit 15, respectively. Measure and output by using a sensor and a speed sensor.

Torque application part is pitch angle of vehicle

And pitch speed

Determine whether or not the pitch motion control torque output from the torque converter is applied to the torque forming unit 15 according to the direction of the match, and includes a determiner 17 and a multiplier 18. The determination unit 17 outputs "1" only when the pitch angle of the vehicle and the direction of the pitch speed coincide, and outputs "0" when it does not match. The multiplier 18 multiplies and outputs the value output from the determination unit 17 with the value output to the torque converter 14. That is, only when the pitch angle of the vehicle and the direction of the pitch speed coincide with each other, the torque forming unit 15 receives the pitch motion control torque output from the torque converting unit 14 only when the output of the determining unit 17 is "1". To apply.

8 is a diagram illustrating a road surface profile for simulating a vehicle pitch motion.

The road surface of FIG. 8 is a so-called SIGNSWEEP road surface, and the curvature of the road surface has a SINE shape, and as the vehicle progresses, the size of the SINE curvature decreases but the frequency of the SINE curvature increases.

9 is a diagram illustrating a simulation result of a vehicle pitch motion in a time domain.

As shown, FIG. 9 is a result of the vehicle traveling on the road surface of FIG. 8 at a speed of 40 kph, compared with the case in which the pitch motion control is performed with the control according to an embodiment of the present invention. It can be seen that the pitch motion is reduced.

FIG. 10 shows that the pitch motion is reduced in a frequency range of 1 to 2 Hz, which is a frequency range in which a person feels sensitive to the pitch motion of the vehicle, by converting the result in the time domain of FIG. 9 into the frequency domain.

So far, the present invention has been described with reference to the embodiments. Those skilled in the art will understand that the present invention may be implemented in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. Therefore, the scope of the present invention should not be construed as being limited to the above-described examples, but should be construed to include various embodiments within the scope of the claims and equivalents thereof.

The present invention can be used in the field of manufacturing in-wheel motor-driven electric vehicles.

Claims

For each of the left and right front and rear wheels of a six-wheeled electric vehicle, the driving or braking force of the wheel generated by friction between the wheel and the road surface rotating according to the torque of the in-wheel motor is displayed. In-wheel motor-driven electric vehicle, characterized in that it comprises a suspension provided with a spring that extends or compresses as it acts on the vehicle body by the component force that prevents the vertical movement of the vehicle body due to the pitch movement while driving the vehicle by this angle Pitch motion control device.
The method of claim 1,

The directions of braking force or driving force of the left and right front wheels and the left and right rear wheels are the same, and the direction of the braking force or the driving force of the left and right middle wheels of the six-wheeled electric vehicle is opposite to the direction of the braking force or the driving force of the left and right front wheels and the left and right rear wheels. Characterized in that it has a pitch motion control device of the in-wheel motor drive electric vehicle.
The method according to claim 1 or 2,

The sum of the driving force or braking force of all wheels of the six-wheeled electric vehicle generated by friction with the road surface becomes "0", and the driving force of all wheels of the six-wheeled electric vehicle generated by friction with the road surface or A pitch motion control device for an in-wheel motor-driven electric vehicle, characterized in that the sum of turning moments generated by the braking force becomes "0".
A first subtractor outputting a deviation between a target pitch speed of a driver and a pitch speed of the electric vehicle output from the six-wheel electric vehicle;

A second subtractor outputting a deviation between a target longitudinal speed of a driver and a longitudinal speed of the electric vehicle output from the electric vehicle;

A first PI controller configured to proportionally integrate and control a value output from the first subtractor, thereby outputting a component force that hinders vertical movement of the vehicle body;

A torque converter for multiplying the component force by the wheel radius of a six-wheeled electric vehicle of the same size and outputting a pitch motion control torque to be applied to the left and right front wheels and the left and right rear wheels for pitch motion control;

A second PI controller configured to proportionally integrate a value output from the second subtractor to output a driving torque for following a target longitudinal speed of the driver;

A torque forming unit for obtaining torques of all wheels of the six-wheeled electric vehicle by using the pitch movement control torque and the drive torque output from the second PI controller;

For each of the left and right front and rear wheels of a six-wheeled electric vehicle, the driving or braking force of the wheel generated by friction between the wheel and the road surface rotating according to the torque of the in-wheel motor is displayed. This suspension angle includes a suspension device having a spring that is extended or compressed by acting on the vehicle body as a component that prevents the vertical movement of the vehicle body due to the pitch movement while driving the vehicle, the torque of the wheel obtained from the torque forming unit An electric vehicle that measures and outputs a pitch speed, a pitch angle, and a longitudinal speed of the electric vehicle being driven by the rotation of the wheel using a pitch speed sensor, a pitch angle sensor, and a speed sensor; And

And an application unit for determining whether the pitch motion control torque is applied to the torque forming unit according to whether the pitch angle and the pitch speed of the electric vehicle coincide with each other.
The method of claim 4, wherein

The pitch movement control device of the in-wheel motor drive electric vehicle, characterized in that the target pitch speed of the driver is set to zero.
The method of claim 4, wherein

The torque of all the wheels is calculated using the following equation, pitch motion control apparatus of the in-wheel motor drive electric vehicle.

[Equation]

At this time,
Is the pitch motion control torque to be applied to the left and right front wheels and the left and right rear wheels for pitch motion control,
Is the driving torque for following the driver's target longitudinal speed,
Is the torque of the left front wheel,
Is the torque of the right front wheel,
Is the torque of the left middle wheel,
Is the torque of the right middle wheel,
Is the torque of the left rear wheel and
Represents the torque of the right rear wheel.
The method of claim 4, wherein

The directions of the braking force or driving force of the left and right front wheels and the left and right rear wheels are the same, and the direction of the braking force or the driving force of the left and right middle wheels of the six-wheeled electric vehicle is opposite to the direction of the braking force or the driving force of the left and right front wheels and the left and right rear wheels. Characterized in that it has a pitch motion control device of the in-wheel motor drive electric vehicle.
The method of claim 4, wherein

The sum of the driving force or braking force of all wheels of the six-wheeled electric vehicle generated by friction with the road surface becomes "0", and the driving force of all wheels of the six-wheeled electric vehicle generated by friction with the road surface or A pitch motion control device for an in-wheel motor-driven electric vehicle, characterized in that the sum of turning moments generated by the braking force becomes "0".
The method according to any one of claims 4 to 8,

The application unit,

A determination unit which checks whether the direction of the pitch angle and the pitch speed of the electric vehicle coincides, and outputs "1" if they match and outputs "0" if they do not match; Wow

And a multiplier configured to multiply the output value of the determination unit by the pitch motion control torque value and output the multiplier.