KR100658770B1 - Pump operation control method and apparatus of motor for EHB system - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control apparatus for a hydraulic pump for generating brake hydraulic pressure and a control method thereof, and more particularly, to a control apparatus for a motor for applying a driving force to the hydraulic pump and a method thereof.

Conventionally, when the duty ratio of the PWM signal is set too high, the driving noise of the hydraulic pump is generated a lot. On the other hand, when the duty ratio of the PWM signal is set too low, the pressure of the accumulator increases. The piston is prevented from reciprocating due to the pressure difference between the two ends of the piston. As a result, the rotation of the hydraulic motor is forcibly stopped so that an overvoltage higher than the rated driving voltage is applied to the hydraulic motor to drive the hydraulic motor and the hydraulic motor. The furnace may be damaged.

The present invention has been made to solve the above problems, an object of the present invention is to calculate the hydraulic discharge amount discharged by the pump, to estimate the rotational speed of the motor corresponding to the calculated discharge amount, the estimated rotation of the motor The present invention provides a motor control apparatus and a method for driving a hydraulic pump to pulse-modulate control a motor to reach a speed.

Hydraulic Pump, Hydraulic Motor

Description

Pump control motor control device for hydraulic brake system and method thereof {Pump operation control method and apparatus of motor for EHB system}

1 is a block diagram for showing a hydraulic pump drive device in a conventional hydraulic brake system.

Figure 2 is a block diagram showing the configuration of a motor control apparatus for driving a hydraulic pump of the present invention.

Figure 3 is a block diagram for showing the control unit configuration of the motor control apparatus of the present invention.

Figure 4 is a flow chart showing the motor control method for driving the hydraulic pump of the present invention.

5 is a simplified configuration diagram of a hydraulic pump applied to the present invention.

* Description of the symbols for the main parts of the drawings *

10 brake hydraulic reservoir 20 hydraulic pump.

30: accumulator 40: hydraulic motor

50: pressure sensor 60: control unit

70: switching means 80: current sensor

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control apparatus for a hydraulic pump for generating brake hydraulic pressure and a control method thereof, and more particularly, to a control apparatus for a motor for applying a driving force to the hydraulic pump and a method thereof.

In general, hydraulic pumps in hydraulic brake systems such as electrohydraulic brake control, anti-lock brake control and traction control control are mechanically connected to the hydraulic motor so that the piston of the hydraulic pump reciprocates by the rotational movement of the hydraulic motor. do. This reciprocating motion generates a vacuum portion lower than atmospheric pressure at the pump inlet, and the vacuum liquid sucks up the brake fluid in the brake fluid reservoir and discharges it to the accumulator. The brake fluid in the accumulator is supplied to the wheel cylinder when necessary.

As shown in FIG. 1, the hydraulic pump driving device in the conventional hydraulic brake system provided with such a hydraulic pump includes a brake fluid reservoir 1, a hydraulic pump 2, an accumulator 3, a hydraulic motor 4, The pressure sensor 5 and the electronic controller 6 are included.

The brake fluid reservoir 1 is connected to the suction side of the hydraulic pump 2 and stores brake fluid. The accumulator 3 is connected to the discharge side of the hydraulic pump 2. The hydraulic pump 2 pumps the brake fluid from the brake fluid reservoir 1 to increase the brake fluid pressure in the accumulator 3. The hydraulic motor 4 is connected to the hydraulic pump 2 to drive the hydraulic pump 2.

The pressure sensor 5 is connected to the accumulator 3 to sense the brake fluid pressure in the accumulator 3.                         

The electronic controller 6 outputs a control signal for driving the hydraulic motor. When the brake pressure is detected by the pressure sensor 5 and the current pressure of the accumulator reaches the preset target pressure, the hydraulic motor 4 Outputs a control signal for stopping).

The switching element 7 interrupts the supply of the battery voltage Vbat to the hydraulic motor 4 according to the control signal of the electronic controller 6.

In the conventional hydraulic pump drive control apparatus, the hydraulic motor is driven by outputting a pulse width modulation (PWM) signal having a predetermined duty ratio to drive the hydraulic motor.

However, when the duty ratio of the PWM signal is set too high, the driving noise of the hydraulic pump is generated a lot. On the other hand, when the duty ratio of the PWM signal is set too low, the pressure of the accumulator increases as the pressure of the accumulator increases. The piston is prevented from reciprocating due to the pressure difference between the two ends of the piston. As a result, the rotation of the hydraulic motor is forcibly stopped so that an overvoltage higher than the rated driving voltage is applied to the hydraulic motor to drive the hydraulic motor and the hydraulic motor. The furnace may be damaged.

Usually, the rated motor voltage is set in consideration of the counter electromotive force generated by the rotation of the motor when designing a hydraulic motor. For example, if the battery voltage is 12V and the counter electromotive force generated during the rotation of the motor is 4V, the motor is designed to be driven by the rated driving voltage of 8V (12V-4V). When the rotation of the hydraulic motor is stopped, Even when no back electromotive force is generated in the hydraulic motor, an overvoltage of 12 V higher than the rated driving voltage of the motor is supplied, which may damage the hydraulic motor and the driving circuit for driving the hydraulic motor.

In addition, the reference pressure at the time of driving and stopping of the hydraulic motor is set, and when the pressure at the driving start point is reached, the driving is started, and when the pressure at the stopping point is reached, the motor stops and there is no pressure between the driving starting point and the pressure at the stopping point. There was a drawback that it could not perform more precise control because it did not take action.

The present invention has been made to solve the above problems, an object of the present invention is to calculate the hydraulic discharge amount discharged by the pump, to estimate the rotational speed of the motor corresponding to the calculated discharge amount, the estimated rotation of the motor The present invention provides a motor control apparatus and a method for driving a hydraulic pump to pulse-modulate control a motor to reach a speed.

In the present invention for achieving the above object, in the hydraulic pump drive motor control apparatus for pumping the braking hydraulic pressure to the accumulator by driving the motor, calculating the hydraulic discharge amount discharged by the pump, corresponding to the calculated discharge amount And estimating a rotational speed of the motor and outputting a control signal using the estimated rotational speed of the motor.

The control unit includes a torque estimator for estimating the torque applied to the motor, a hydraulic discharge amount calculator for calculating the discharge amount using the estimated torque and the pressure of the hydraulic pressure discharged from the pump, and a rotation speed calculation for calculating the rotational speed of the motor. The target rotational speed of the motor is calculated using the hydraulic discharge amount / rotation speed comparison table in which the rotational speed of the motor corresponding to the calculated hydraulic discharge amount is stored, the torque and the hydraulic discharge amount of the estimated motor, and the calculated target rotational speed and Characterized in that it consists of a motor controller for outputting a PWM signal for controlling the motor by proportional control of the actual rotation speed calculated by the rotation speed calculator.

In addition, the control method of the hydraulic pump drive motor configured as described above,

A first step of calculating the amount of hydraulic pressure discharged by the pump, a second step of estimating a target rotational speed of the motor using the calculated hydraulic pressure discharge amount, and a step of outputting a control signal using the estimated target rotational speed of the motor Characterized in that performed in three steps.

The first step is characterized by estimating the torque applied to the motor, calculating the amount of hydraulic pressure discharged using the estimated torque of the motor and the discharge pressure of the pump.

The second step is characterized in that the target rotational speed of the motor is calculated using the hydraulic discharge amount / rotational speed comparison table preset by the torque and the hydraulic discharge amount of the motor estimated in the first step.

In the third step, the control signal is output by proportionally controlling the target rotation speed estimated in the second step and the actual rotation speed.

The control signal of the third step is a pulse width modulation signal.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention.                     

Figure 2 is a block diagram showing the configuration of the motor control apparatus for driving a hydraulic pump of the present invention, Figure 3 is a block diagram for showing a control unit configuration of the motor control apparatus of the present invention, Figure 4 is a hydraulic pump driving motor of the present invention Flow chart showing a control method, Figure 5 is a simplified configuration of a hydraulic pump applied to the present invention.

First, referring to Figure 2, the configuration,

Detects the brake hydraulic pressure supplied to the accumulator 30 by the hydraulic pump 20 for pumping the brake hydraulic pressure in the brake fluid reservoir 10 in which the brake hydraulic pressure is stored and supplying the accumulator 30 to the accumulator 30. Pressure sensor 50, a hydraulic motor 40 for driving the hydraulic pump 20 by receiving a battery voltage BAT, and a current sensor 80 for detecting a current supplied to the hydraulic motor 40. ), The switching element 70 for intermitting the supply of the battery voltage BAT to the hydraulic motor 40, and the value detected from the pressure sensor 50 and the current sensor 80 to perform a predetermined operation. And a control unit 60 for outputting a control signal for controlling the rotational speed of the hydraulic motor 40 according to the calculation result.

The brake hydraulic reservoir 10 is connected to the suction side of the hydraulic pump 40 and stores the brake hydraulic pressure. The accumulator 30 is connected to the discharge side of the hydraulic pump 40. The hydraulic pump 40 pumps the brake hydraulic pressure from the brake hydraulic reservoir 10 to increase the brake hydraulic pressure in the accumulator 30. The hydraulic motor 40 is connected to the hydraulic pump 20 to drive the hydraulic pump 20.

The pressure sensor 50 is connected to the accumulator 30 to sense the brake hydraulic pressure in the accumulator 30.

As shown in FIG. 3, the controller 60

Torque estimator 61 for estimating the torque acting on the hydraulic motor 40 by inputting the discharge pressure of the hydraulic pump 20 output from the pressure sensor 50, and in the estimated torque and the hydraulic pump 20 The motor rotation speed which calculates the rotational speed of the current hydraulic motor 40 by inputting the hydraulic discharge amount calculator 62 which calculates the discharge amount using the discharged hydraulic pressure, and the current value output from the current sensor 80. Torque and hydraulic discharge amount of the hydraulic discharge amount / rotational speed comparison table 65 in which the calculator 63, the rotational speed of the hydraulic motor 40 corresponding to the calculated hydraulic discharge amount, and the estimated hydraulic motor 40 are stored. Calculates the target rotational speed of the hydraulic motor 40, and outputs a PWM signal for controlling the hydraulic motor 40 by proportionally controlling the calculated target rotational speed and the actual rotational speed calculated by the rotational speed calculator 63. It consists of a motor controller 64.

The control method is as shown in Figure 4,

Estimating a torque applied to the hydraulic motor 40, calculating a hydraulic discharge amount of the hydraulic pump 20 by using the estimated torque of the hydraulic motor 40, and using the calculated hydraulic discharge amount in advance Selecting a target rotational speed using the hydraulic discharge amount / rotational speed comparison table 65, and outputting a control signal so that the rotational speed of the current hydraulic motor 40 follows the selected target rotational speed.

The control signal is a pulse width modulation signal, and causing the rotational speed of the hydraulic motor 40 to follow the target rotational speed is achieved by changing the duty ratio of the pulse width modulation signal.

Hereinafter, the detailed operation will be described.

First, the control unit 60 calculates the hydraulic discharge amount output from the hydraulic pump 20, the hydraulic discharge amount of the torque T acting on the hydraulic motor 40 for driving the hydraulic pump 20 and the discharge side Since the pressure P is calculated, the pressure P on the discharge side is sensed by the pressure sensor 50, but the torque T is calculated by a predetermined arithmetic operation.

As shown in FIG. 5, the hydraulic pump 20 has a structure in which a circular cam 20a which is eccentric to the hydraulic motor 40 and converts the rotational motion of the motor into a reciprocating motion pushes the piston 20b. The torque T is closely related to the load of the hydraulic motor 40, that is, the force acting on the piston 20b of the hydraulic pump 20, the cross-sectional area of the piston 20b, and the degree of eccentricity.

The formula for calculating the torque T is as follows.

[Equation 1]

(Where T is the torque, A is the cross-sectional area of the piston, d is the eccentricity, P is the hydraulic pressure detected by the pressure sensor, and ㅡ is the direction of the torque.)

When the torque T is calculated as described above, the hydraulic discharge amount calculator 62 of the controller 60 calculates the hydraulic discharge amount of the hydraulic pump 20 by using the calculated torque T and the pressure P. Done.

The motor controller 64 inputs the calculated hydraulic discharge amount and selects a target rotational speed of the hydraulic motor 40 driving the hydraulic pump 20 by using a preset hydraulic discharge amount / rotation speed comparison table 65. . That is, the rotational speed of the motor corresponding to the hydraulic discharged pumping amount is selected using the hydraulic discharge amount / rotational speed comparison table 65. At this time, the motor rotational speed calculator 63 detects the current supplied to the hydraulic motor 40 output from the current sensor 80 to calculate the current rotational speed of the hydraulic motor 40. Is the same as

[Equation 2]

Where Φ is the rotational speed of the motor, V is the battery voltage, i is the current value detected by the current sensor, R is the motor resistance, k is the motor constant, and Duty ratio is the pulse width of the motor drive signal.

As described above, the motor rotational speed calculator 63 calculates the rotational speed of the current hydraulic motor 40, and the motor controller 64 outputs the current rotational speed and the output of the motor rotational speed calculator 63. The target rotational speed is input, and the pulse width modulation signal through the proportional control method is output to the switching means 70 so as to reach the target rotational speed. At this time, the main purpose of the proportional control is to eliminate the difference between the target rotational speed command and the current rotational speed command.                     

In addition, it is also possible to adjust the rotational speed of the hydraulic motor 40 by adjusting the duty ratio of the pulse width modulation signal.

The control unit 60 repeats the above process at intervals of a predetermined set time, thereby enabling almost real-time control.

 As described above, in the present invention, the discharge amount of the pump, that is, the rotational speed of the hydraulic motor is controlled based on the amount of hydraulic pressure actually discharged from the hydraulic pump and the actual rotational speed of the motor driving the hydraulic pump. Speed control can be implemented, thereby reducing operating noise during braking operation, providing a reliable product to the user.

Claims (10)

Hydraulic pump driving pumping braking hydraulic pressure to the accumulator by driving a hydraulic motor comprising a pressure sensor for measuring the discharge oil pressure of the hydraulic pump and a current measuring means for measuring the current supplied to the hydraulic motor for driving the hydraulic pump. In the motor control device for And a control unit for calculating the hydraulic discharge amount discharged by the hydraulic pump, estimating the rotational speed of the hydraulic motor corresponding to the calculated discharge amount, and outputting the hydraulic motor control signal using the estimated rotational speed of the hydraulic motor. Motor control device for driving the pump of the hydraulic brake system, characterized in that. The method of claim 1, The control unit inputs the discharge pressure of the hydraulic pump output from the pressure sensor to estimate the torque applied to the hydraulic motor, and the discharge amount by using the estimated torque and the discharge pressure of the hydraulic pump detected by the pressure sensor A hydraulic discharge amount calculator for calculating a pressure, a motor rotation speed calculator for calculating a rotation speed of a current hydraulic motor by inputting a current value output from the current sensor, and a hydraulic pressure in which a rotation speed of a hydraulic motor corresponding to the calculated hydraulic discharge amount is stored. The target rotational speed of the hydraulic motor is calculated using the discharge amount / rotation speed comparison table and the estimated torque and hydraulic discharge amount of the hydraulic motor, and the actual rotational speed calculated by the rotation speed calculator to follow the calculated target rotational speed is calculated. It consists of a motor controller that outputs a control signal for controlling the hydraulic motor by proportional control. A motor control device for driving the pump of the hydraulic brake system according to. The method of claim 2, Estimating torque in the torque estimator is a motor control device for driving a pump of a hydraulic brake system, characterized in that performed by the following equation. [Equation]

(Where T is the torque, A is the cross-sectional area of the piston in the pump, d is the eccentricity, P is the hydraulic pressure detected by the pressure sensor, ㅡ is the torque direction). The method of claim 2, The motor control apparatus for driving a pump of a hydraulic brake system, characterized in that calculating the current rotation speed in the motor rotation speed calculator is performed by the following equation. [Equation]

Where Φ is the rotational speed of the motor, V is the battery voltage, i is the current value detected by the current sensor, R is the motor resistance, k is the motor constant, and Duty ratio is the pulse width of the motor drive signal. The method of claim 2, And a control signal output from the motor controller is a pulse width modulated signal, and controls the rotation speed of the motor by adjusting the duty ratio of the pulse width modulated signal. In the motor control apparatus of a hydraulic brake system comprising a pressure sensor for measuring the discharge oil pressure of the hydraulic pump, and a current measuring means for measuring the current supplied to the hydraulic motor for driving the hydraulic pump, A first step of calculating the amount of hydraulic pressure discharged by the hydraulic pump, a second step of estimating a target rotational speed of the hydraulic motor by the calculated hydraulic discharge amount, and a current rotational speed following the estimated target rotational speed of the hydraulic motor The pump drive control method of the hydraulic brake system, characterized in that performed in a third step of outputting a motor control signal. The method of claim 6, The first step includes estimating the torque acting on the motor, and calculating the amount of hydraulic pressure discharged using the estimated torque of the motor and the discharge pressure of the pump sensed by the pressure sensor. Pump drive control method of brake system. The method of claim 6, The second step is a pump drive control method of the hydraulic brake system, characterized in that for selecting the target rotational speed of the motor using the hydraulic discharge amount / rotational speed comparison data preset in the hydraulic discharge amount calculated in the first step. The method of claim 6, The control signal of the third step is a pulse width modulation signal, the pump drive control method of the hydraulic brake system, characterized in that for controlling the rotational speed of the motor by adjusting the duty ratio of the pulse width modulation signal. The method of claim 7, wherein Estimate the torque applied to the motor is a pump drive control method of a hydraulic brake system, characterized in that performed by the following equation. [Equation]

(Where T is the torque, A is the cross-sectional area of the piston in the pump, d is the eccentricity, P is the hydraulic pressure detected by the pressure sensor, ㅡ is the torque direction).

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