KR101499995B1 - Device and method controlling motor position and creep of fuel cell vehicle - Google Patents

Abstract

The present invention relates to a motor position and creep control device for an electric vehicle and a control method thereof. More particularly, the present invention relates to a control method for a motor position and creep control device of an electric vehicle, To a motor position and a creep control device of an electric vehicle capable of preventing the motor from being pushed and released when the motor is stopped or restarted from the back road by causing the motor to perform position control or creep torque control.

To this end, the present invention provides a control system for a vehicle, comprising: a start determining unit for determining whether to enter a motor position control or a creep torque control by using detection information of an uphill angle sensor for detecting a backlash angle of a running road at the time of brake release after stopping a vehicle; A motor position control unit for calculating a motor torque for backlash compensation and a motor torque for maintaining the motor position and maintaining the position of the motor; A creep torque control unit for generating a creep torque of the motor through a time delay when the brake is released, and controlling the motor speed to a constant level; And a controller for controlling the motor position and the creep of the electric vehicle.

Fuel cell, vehicle, motor, position, jungle judgment, creep, torque, backlash, brake

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a motor position and creep control apparatus for an electric vehicle,

The present invention relates to a motor position and creep control device for an electric vehicle and a control method thereof, and more particularly, To a motor position and a creep control device of an electric vehicle capable of preventing the motor from being pushed and released when the motor is stopped or restarted from the back road by causing the motor to perform position control or creep torque control.

Since the idle torque of the engine is transmitted to the torque converter and the transmission even in the case where the ordinary gasoline engine vehicle does not step on the excel pedal and the brake pedal while the vehicle is running, creep traveling is performed while the vehicle keeps running at a small speed.

As shown in the attached FIG. 5, the vehicle in the running state of the backlit road is subjected not only to the rolling resistance but also to the slope resistance as mgsinθ. Due to the tilting resistance, After stopping, release the brake pedal and the vehicle will be pushed back.

In order to get out of the situation where the vehicle is pushed backward, the driver operates again to prevent the vehicle from being pushed, such as by stepping on the brake pedal or operating the accelerator pedal.

In order to prevent the inconvenience of the operation for preventing the vehicle from being pushed back from the back road running, a certain amount of frictional brakes are maintained to prevent the throttle from being applied even when the excel pedal and the brake pedal are not applied. A creep control technique for releasing a friction brake and switching to a normal operation state is introduced.

On the other hand, since the electric vehicle travels only by the configuration of the motor drive system (motor, speed reducer, wheel) without a separate engine, idle torque by the motor is not automatically generated when the vehicle is stopped, and creep does not occur like the gasoline engine vehicle .

Therefore, the creep function must be realized through the motor torque control in order to make the creep function of the gasoline engine vehicle to the electric vehicle.

That is, a pure electric vehicle driven by a motor such as a fuel cell vehicle requires a creep control algorithm for generating a torque similar to the engine idle torque in order to satisfy the same running feeling as a general gasoline mass-produced vehicle, Along with the development of control algorithms, a technique to prevent jamming in stopping and restarting after stopping is also being studied.

Of course, in a vehicle driven by a motor alone such as a fuel cell and an electric vehicle, it is possible to easily control the motor driving force without introducing an additional system (for example, by determining the backlash and increasing the motor driving torque) It is possible to realize the prevention of the skidding of the vehicle.

That is, as shown in FIG. 4, it is possible to implement a method of determining the backlash by applying an angle sensor or a threshing judgment algorithm to the fuel cell and the electric vehicle, and increasing the motor torque according to the determined result, The method can be implemented simply because it is easy to directly control the motor driving force.

However, there is a need for a portion for calculating the necessary motor torque amount, and the amount of calculation depends on various parameters such as the angle of back and the number of passengers, thus requiring a lot of errors and experiments.

Particularly, when it is judged that the existing creep torque control logic is maintained, it is difficult to accurately calculate the amount of additional motor torque to be increased, and it is difficult to accurately maintain the position of the vehicle , The number of passengers, the angle of backing, etc. If the given environment changes, the amount of motor torque must be calculated again to maintain the position of the vehicle. Otherwise, the vehicle may be pushed forward or excessively pushed forward.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide a motor position control or a creep torque control for maintaining a stopped position based on a back angle measurement information when the brake is released while the vehicle is in motion. And the creep torque control is performed after checking the stabilization of the motor position at the stopped position in the motor position control. By doing so, it is possible to keep the jogging at the minimum on the back road without operation of the brake pedal and the accelerator pedal, The present invention provides a motor position and creep control device for an electric vehicle in which the current position of a vehicle can be maintained regardless of a change in the number of passengers and the like, and is then naturally switched to a creep torque mode.

According to an aspect of the present invention, there is provided a control system for a vehicle, comprising: a start determining unit for determining whether to enter a motor position control or a creep torque control using detection information of an angle sensor, Wow; A motor position control unit for calculating a motor torque for maintaining the motor position and maintaining the position of the motor; A creep torque control unit that generates a creep torque of the motor through a time delay and controls the motor speed to a constant level; And a controller for controlling the motor position and the creep of the electric vehicle.

In one preferred embodiment, the motor position control unit sets a target input angle by adding an offset angle to compensate for a steady state angle error to the current angle of the motor at the time of entry of the motor position control, Is input to the PD controller to calculate the torque for maintaining the motor position.

In another preferred embodiment, the creep torque control unit includes a torque converter hydraulic pressure modeling unit that generates a creep torque of the motor through a time delay, and a torque converter control unit that controls the torque of the motor to a level for keeping the motor speed constant. And a state model unit.

In addition, a filter is connected to the final torque output end of the creep torque control unit to adjust the change in creep torque so that the sudden change does not occur.

According to an aspect of the present invention, there is provided a control method for a vehicle, including: determining whether a vehicle is backlash by measuring a back angle of a running road when a brake is released, ; A motor position control step of increasing the motor torque to maintain the motor position when the back angle is smaller than the back angle judgment reference reference inclination angle, and when the back angle is larger than the back angle judgment reference reference inclination angle; A motor position stabilization check step of determining whether to continue the motor position or enter the creep torque control step after a certain time after entering the motor position control; A creep torque control step in which the motor torque is constantly increased from the stabilization torque for maintaining the motor position to the maximum creep torque as a starting point; The present invention provides a motor position and creep control method for an electric vehicle.

As a preferred embodiment of the present invention, there is provided a method of controlling a vehicle, comprising the steps of: calculating motor torque in consideration of backlash for prevention of shock to eliminate backlash when the vehicle is stopped at the time of braking while the vehicle is running; And a backlash compensation control step of controlling the backlash compensation.

The step of controlling the motor position includes: setting a target input angle by adding an offset angle to compensate for a steady state angle error to the current angle of the motor at the time of entry of the motor position control; Calculating a motor torque for maintaining a position of a motor by inputting a difference between a current angle and a target input angle to a PD controller; (Mgsin &thetas;) by the detection of each angle sensor is applied to the motor so that the final motor torque, which is the motor torque added to the torque corresponding to the backing load value, is supplied to the feedforward input so as to maintain the motor position; .

The motor position stabilization check step may include: if the torque change amount of the motor is smaller than the motor torque stabilization reference value and the position change amount of the motor is smaller than the motor position stabilization reference value, the stabilization determination count is performed to determine that the motor position is stably maintained A process; Determining whether a shift to a creep torque control step should be performed; .

Further, when the stabilization torque for maintaining the motor position is smaller than the maximum creep torque, the mode is switched to the creep torque control mode, and when the stabilization torque for maintaining the motor position is larger than the creep torque, the motor position is maintained.

The motor position control and the creep torque control are immediately released when the accelerator pedal or the brake pedal is depressed.

Through the above-mentioned means for solving the problems, the present invention provides the following effects.

According to the present invention, when the electric vehicle running only by the motor drive is stopped, the shock prevention mode for applying the backlash compensation torque is performed, the backlash judgment logic is executed, and the position control of the motor After the brake pedal is released, the motor position stabilization at the stopped position is checked and the creep torque control is performed so that the brake pedal and the accelerator pedal can be operated without any operation of the brake pedal and the accelerator pedal, It is possible to maintain the current position of the vehicle on the back road and to prevent the phenomenon such as jumping or sudden start regardless of changes in the angle and the number of passengers, thereby improving the driving stability.

In particular, the motor position control for applying the motor torque for maintaining the motor position before the vehicle is pushed is performed through the detection of the back angle sensor and the judgment angle determining logic using the back angle sensor, and the torque corresponding to the back- There is an advantage that stabilization for maintaining the position of the motor can be performed more quickly by applying to the torque.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a control block diagram showing a motor position and creep control device of an electric vehicle according to the present invention; FIG.

The present invention is to provide a motor position closed loop control method for maintaining the position of the motor (the rotor position of the motor) during traveling on the back side while compensating for the disadvantages of the conventional motor torque open loop control. A shock prevention mode for applying a backlash compensating torque at the time of stopping is executed and a tripping judgment logic is executed and a current position of the motor is fed back while being automatically switched to a position control mode upon release of the brake, The motor torque for maintaining the current position is automatically calculated and used for maintaining the position of the vehicle.

The motor position and creep control device 10 according to the present invention calculates the back angle of the traveling path based on the detection value of the back angle sensor 50 and determines whether or not the vehicle enters the motor position control or creep torque control mode A motor position control unit 20, and a creep torque control unit 30. As shown in Fig.

When the vehicle is stopped after the vehicle is stopped, the backlash determining unit 40 determines whether the vehicle enters the motor position control or creep torque control mode according to the back angle of the running road on which the vehicle is running.

That is, the back-up determining unit 40 determines whether to enter the motor position control or the creep torque control using the detection information of the back-up angle sensor that detects the back-up angle of the traveling road at the time of brake release after stopping the vehicle, If the measured backlash angle is smaller than the reference inclination angle for judging the backlash, it is determined to enter the creep torque control stage. If the measured backlash angle is greater than the reference inclination angle for judging the backlash, do.

The motor position control unit 20 controls the motor position (the rotor position of the motor). The motor position control unit 20 calculates an offset angle to compensate for the angular error of the steady state from the current angle of the motor at the time of entry of the motor position control. In addition, the target input angle is set, and the difference between the current angle and the target input angle is inputted to the PD controller to automatically calculate the motor torque for maintaining the position of the vehicle, that is, the position of the motor.

The creep torque control unit 30 includes a torque converter hydraulic pressure modeling unit 32 for forming a hydraulic pressure such as an actual torque converter and a torque converter steady state model unit 34. The torque converter hydraulic pressure modeling unit 32) causes a creep torque of the motor to be generated through a time delay when the brake is released to release the brake pedal when the vehicle is stopped by stepping on the brake pedal.

That is, due to the process of forming the torque converter hydraulic pressure by the torque converter hydraulic pressure modeling unit 32, the creep torque of the motor appears through the time delay.

The torque converter steady state model unit 34 simulates the characteristic that the motor torque transmission force increases as the input / output speed difference of the torque converter hydraulic pressure model increases, The torque control is performed to reduce the torque according to the increase of the motor torque.

A filter 36 is additionally connected to the final torque output end of the creep torque control unit 30 to adjust the change in creep torque so that the sudden change does not occur.

Hereinafter, the motor position and creep control method of the present invention based on the above-described configuration will be described.

FIG. 3 is a control block diagram illustrating a creep travel control method of an electric vehicle according to an embodiment of the present invention; FIG. And changes in the motor drive torque are shown.

The present invention is characterized by comprising a backlash compensating control step of removing a backlash to control shock prevention by backlash while a vehicle is stopped by applying a brake pedal and a backlash compensating step of measuring a backlash angle of a traveling road at the time of brake release, A motor position control step for increasing the motor torque to maintain the motor position when the back angle is larger than the inclination angle for judging the back angle, the motor position stabilization check step, the creep torque control step, etc. It is possible to prevent phenomena such as jumping or sudden start in a back road without operating a brake pedal and an accelerator pedal.

First, in the backlit road traveling situation, when the brake pedal is depressed, the vehicle is stopped and the backlash compensation control step for unconditionally removing the backlash is performed, thereby performing the shock prevention control by the backlash.

In other words, if a motor torque is suddenly applied in a situation where there is a backlash between the motor and the speed reducer or between the speed reducer and the traveling wheels, a great impact is applied to the reducer side to cause the vehicle body to momentarily shake, Motor position control is performed.

Therefore, in order to compensate for the error between the current angle of the motor and the steady state angle due to the backlash between the motor rotor and the speed reducer, i.e., when the brake is applied while the vehicle is running, the backlash is taken into consideration A backlash compensation control step is performed by a process of calculating a motor torque and a process of applying a torque to the motor at a level at which backlash can be eliminated.

At this time, motor torque for solving the backlash, that is, motor driving force (F1 in Fig. 3) for correcting the motor position error due to the backlash in the state in which the brake pedal is depressed is required to be small enough to eliminate backlash.

Next, when the brake is released when the brake pedal is released in the state where the shock prevention control by the backlash is performed, if the vehicle is on the back road, the back load suddenly occurs. Therefore, as a preceding step for preventing the vehicle from being pushed back, It proceeds.

That is, it is judged whether or not the motor enters into the motor position control or the creep torque control by using the detection information of the back angle sensor for detecting the back angle of the running path when the brake is released. If the back angle is smaller than the reference inclination angle for judging the back angle, So that the motor enters the motor position control mode when the back angle is larger than the reference inclination angle for judging the back plate.

In other words, if the angle of inclination of the angle sensor is inputted from the angle determining unit after the release of the brake pedal, if the angle of the angle of inclination is equal to or greater than the predetermined reference angle of inclination, the motor enters the motor position control mode before the vehicle is pushed, If the inclination angle is less than the inclination angle, the motor position control for maintaining the motor position is performed irrespective of the external load noise, so that torque necessary for maintaining the motor position is generated. As shown below, . ≪ / RTI >

In the motor position control mode, a target angle is set by adding an offset angle to the current angle of the motor at the entry of the motor position control to compensate for the angular error of the steady state. Calculating the motor torque to maintain the position of the motor by inputting the difference to the PD controller, calculating a motor torque at which the calculated motor torque is supplied as the feed forward input (mgsin &thetas; A process is performed in which the final motor torque added to the torque equivalent to the load value is applied to the motor to maintain the motor position.

Therefore, the stationary position of the vehicle, that is, the current position of the motor, is maintained regardless of the backlash load which causes the phenomenon that the vehicle is pushed on the backing road.

That is, as the back-up load is suddenly applied when releasing the brake pedal, the final motor torque calculated in order to maintain the motor position in the motor position control mode state, that is, the motor driving force (F2 in Fig. 3) And so on.

Particularly, the back angle by detection of the back angle sensor, i.e., back plate load value (mgsin &thetas;) is provided as a feedforward input to the motor position control unit for motor position control, So that the motor position retention can be more stabilized in a short period of time.

On the other hand, the backing load value (mgsinθ) input as the feedforward value is calculated by the backing angle and the vehicle weight, the backing angle is continuously measured from the backing angle sensor and the weight change is not detected, It can be sufficiently compensated in the motor position feedback control section.

Then, after a predetermined time, the motor position stabilization check step proceeds as follows.

The step of checking the motor position stabilization is a step of determining whether a motor torque change amount and a position change amount have occurred, and determining whether the position of the vehicle, that is, the position of the motor, is continuously maintained or converted to a creep torque.

For the motor position stabilization check, if the torque change amount of the motor is smaller than the motor torque stabilization reference value or the motor position change amount is smaller than the motor position stabilization reference value, the stabilization determination count is increased and the stabilization determination count is set to the stabilization determination reference counter value , It is determined that the motor position is stably maintained.

Therefore, the motor position stabilization check step is started after releasing the brake, and if it is determined that the motor position is stably maintained, it is determined whether or not the shift to the creep torque control step is required.

That is, when it is determined that the motor position control is stabilized, when the stabilization torque for maintaining the motor position is smaller than the maximum creep torque, the mode is switched to the creep torque control mode so that the stabilization torque for maintaining the motor position is gradually increased And the creep torque control is performed.

More specifically, when the stabilization torque for maintaining the motor position is smaller than the creep torque, the control is switched to the creep torque control stage so that the stabilized motor torque for maintaining the motor position is increased from the starting point to the maximum creep torque by the motor torque ), The vehicle slowly moves. On the other hand, when the stabilization torque for maintaining the motor position is larger than the creep torque, the motor position remains unchanged.

At this time, the above-described control for maintaining the motor position and the creep torque control are released by pressing the accelerator pedal or the brake pedal.

As described above, when the electric vehicle traveling only by the motor drive runs on the backing path, the backlash is removed when the vehicle is stopped, and the motor position control or the creep torque control is performed according to the determination of the backlash when the brake is released again. The present position of the vehicle, that is, the position of the motor is maintained, and then the mode is switched to the creep torque control mode. Thus, even if the vehicle restarts after stopping the start of the vehicle, the vehicle runs without jumping or sudden start.

1 is a control block diagram showing a motor position and creep control device of an electric vehicle according to the present invention;

2 is a flowchart for explaining a motor position and a creep control method of an electric vehicle according to the present invention,

FIG. 3 is a control block diagram of a motor position and creep control method of an electric vehicle according to the present invention,

FIG. 4 is a schematic view illustrating an example using an angle-of-inclination sensor or a forestry judgment algorithm in an existing electric vehicle;

5 is a schematic view for explaining a situation in which a vehicle is subjected to an inclined resistance during traveling on a back road.

Description of the Related Art

10: Motor position and creep control device

20: Motor position control section

30: Creep torque control section

32: Torque converter hydraulic forming model part

34: Torque converter steady state model part

36: Filter

40:

50: angle sensor

Claims (11)

A start determining unit for determining whether to enter the motor position control or the creep torque control using the detection information of the backing plate angle sensor for detecting the backing angle of the traveling path when the brake is released after the vehicle is stopped; A motor position control unit for calculating a motor torque for maintaining the motor position and maintaining the position of the motor; The torque converter hydraulic pressure modeling unit causes the torque torque of the motor to be generated through a time delay due to the hydraulic pressure forming process of the torque converter, and in order to maintain the speed of the motor at a constant speed by the torque converter steady state modeling unit, A creep torque control section for performing control to reduce the torque; And a controller for controlling the motor position and the creep of the electric motor. The method according to claim 1, The motor position control unit sets a target input angle by adding an offset angle to compensate for the angular error of the steady state to the current angle of the motor at the entry of the motor position control and outputs the difference between the current angle and the target input angle to the PD controller And calculates a torque for inputting and holding the motor position. delete The method according to claim 1, Wherein a filter is connected to a final torque output end of the creep torque control unit to adjust a change in creep torque so that a sudden change does not occur. Determining whether or not the vehicle enters the motor position control or the creep torque control by determining whether the vehicle is backlash to the back of the vehicle by measuring an angle of backlash of the running road when the brake is released; A motor position control step of increasing the motor torque to maintain the motor position when the back angle is smaller than the back angle judgment reference reference inclination angle, and when the back angle is larger than the back angle judgment reference reference inclination angle; A motor position stabilization check step of determining whether to continue the motor position or enter the creep torque control step after a certain time after entering the motor position control; A creep torque control step in which the motor torque is constantly increased from the stabilization torque for maintaining the motor position to the maximum creep torque as a starting point; And controlling the motor position and creep of the electric motor. The method of claim 5, Calculating a motor torque in consideration of backlash to prevent shock when the brake is applied while the vehicle is stopped and removing the backlash, and applying a calculated torque to the motor to eliminate the backlash, Further comprising the step of controlling the motor position and creep control of the electric motor. The method of claim 5, Wherein the back angle is determined by the back angle sensor in the back plate determining step. 6. The method of claim 5, wherein the motor position control step comprises: Setting a target input angle by adding an offset angle to compensate for a steady state angle error to the current angle of the motor at the time of entry of the motor position control; Calculating a motor torque for maintaining a position of a motor by inputting a difference between a current angle and a target input angle to a PD controller; (Mgsin &thetas;) by the detection of each angle sensor is applied to the motor so that the final motor torque, which is the motor torque added to the torque corresponding to the backing load value, is supplied to the feedforward input so as to maintain the motor position; And controlling the motor position and creep of the electric motor. 6. The method of claim 5, wherein the step of checking the motor position stabilization comprises: Determining that the motor position is stably maintained by performing a stabilization determination count if the torque change amount of the motor is smaller than the motor torque stabilization reference value or the motor position change amount is smaller than the motor position stabilization reference value; Determining whether a shift to a creep torque control step should be performed; And controlling the motor position and creep of the electric motor. The method of claim 9, When the stabilization torque for maintaining the motor position is smaller than the maximum creep torque, the mode is switched to the creep torque control mode, and when the stabilization torque for maintaining the motor position is larger than the creep torque, the motor position is maintained And creep control method. The method of claim 5, Wherein the motor position control and the creep torque control are released as soon as the accelerator pedal or the brake pedal is depressed.

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