KR20140036904A - Integrated control apparatus of logic for damping and restoration by mdps and control method thereof - Google Patents

Abstract

The present invention relates to a device for integrally controlling damping logic and restoration logic by an MDPS system which includes an aimed load determining unit which determines an aimed load based on a steering angle; an actual load estimating unit which estimates an actual load based on column torque and an MDPS output current; a controller which outputs the difference between the aimed load and the estimated actual load, feeds back the outputted value, and controlling the difference of the fed back value and the difference the aimed load and the estimated actual load; and a filter unit which filters the outputted value. The present invention reduces the number of parameters to be tuned by integrating the damping logic and the restoration logic which are separately operated in the past and performing damping and restoration functions with single logic, thereby simplifying a control by the MDPS system. [Reference numerals] (12) Size determining unit; (14) Sign determining unit; (22) Unit converting unit; (30) Control ratio; (AA) Steering angle; (BB) Column torque; (CC) MDPS output voltage; (DD) Frequency (Hz)

Description

INTEGRATED CONTROL APPARATUS OF LOGIC FOR DAMPING AND RESTORATION BY MDPS AND CONTROL METHOD THEREOF}

The present invention relates to an integrated control device and a control method of the damping logic and restoration logic by the MDPS, and more particularly, by integrating the damping logic and the restoration logic to exist separately to individually control by vehicle speed band, MDPS (Motor The present invention relates to an integrated control device for damping logic and restoration logic by MDPS and a control method thereof, which can simplify the control by driven power steering.

MDPS (Motor Driven Power Steering) is a device that facilitates steering by providing a part of the steering torque to be applied to the steering wheel by an auxiliary power source when the vehicle is steered. In other words, the driver's steering intention is monitored through a torque sensor directly connected to the steering wheel, and this signal is inputted by the MDPS to assist the steering power by driving the motor to provide a proper force in consideration of the speed of the current car.

Therefore, it is possible to maintain the stability of the vehicle body by reducing the driver's power by substituting a large force when stopping or driving at a low speed, and by subtracting a small force when driving at a high speed.

MDPS is a steering device that uses an electric monitor instead of the conventional hydraulically operated steering device to provide power, and provides an optimum steering power for each speed, which is environmentally friendly and reduces fuel economy.

Recently, the MDPS has added a damping logic for improving yaw stability during driving and steering of the vehicle and a restoring logic for improving steering resiliency of the vehicle to assist the driver in driving.

However, the existing MDPS has a complicated control because the damping logic and the restoring logic exist separately and are controlled by using different parameters as input values.In addition, the damping logic and the restoring logic are difficult to tune due to the large number of tuning parameters. There was a problem such as not being restored at a specific vehicle speed.

Prior art related to the present invention is Republic of Korea Patent Publication No. 10-2012-0053300 (2012.05.25. Publication, the name of the invention: MDPS control apparatus and method of a vehicle).

The present invention was devised to solve the above-mentioned problems, and by integrating the damping logic and the restoring logic which existed separately for the individual control of the vehicle speed, the present invention is applicable to the MDPS applicable to assisting the damping and restoring function regardless of the vehicle speed. It is an object of the present invention to provide an integrated control device for damping logic and restoration logic and a control method thereof.

In accordance with an aspect of the present invention, an integrated control device for damping logic and restoring logic by MDPS includes: a target load determining unit configured to determine a target load based on a steering angle; An actual load estimator for estimating an actual load based on the column torque and the MDPS output current; A controller for outputting an error between the target load and the estimated actual load and feeding back an output value to control a difference from the error; And a filter unit for filtering the output value.

In the present invention, the target load determination unit comprises: a size determination unit for extracting a load value corresponding to the steering angle from the load table to determine the size of the target load; And a sign determining unit configured to determine a sign of the target load as a positive number when the steering angle is 0 or more and to determine a sign of the target load as a negative number when the steering angle is less than zero.

In the present invention, the steering angle has a value exceeding zero when the steering wheel is rotated in the clockwise direction with respect to the neutral, and has a value less than zero when the steering wheel rotates in the counterclockwise direction.

In the present invention, the actual load estimating unit estimates the actual load by the sum of the MDPS output current measured one cycle before the column torque and the column torque.

In the present invention, the controller is a PID (Proportional Integral Derivative) controller.

In the present invention, the filter unit is characterized in that the low pass filter (LPF).

In accordance with another aspect of the present invention, an integrated control method of damping logic and restoration logic by MDPS includes determining a target load based on a steering angle; Estimating the actual load based on the column torque and the MDPS output current; Calculating an error between the target load and the actual load; Outputting an error between the target load and the estimated actual load, and feeding back an output value to control a difference from the error; And filtering the error between the loads.

The present invention determines the target load by extracting a load value corresponding to the steering angle from the load table in the step of determining the target load, and if the steering angle is 0 or more, determines the sign of the target load as a positive number, If the steering angle is less than zero, the sign of the target load is determined as a negative number.

In the present invention, the steering angle has a value exceeding zero when the steering wheel is rotated in the clockwise direction with respect to the neutral, and has a value less than zero when the steering wheel rotates in the counterclockwise direction.

The present invention is characterized in that the actual load is estimated by the sum of the MDPS output current measured one cycle before the column torque and the column torque in the step of estimating the actual load.

In the present invention, the controller is a PID (Proportional Integral Derivative) controller.

In the present invention, the filter unit is characterized in that the low pass filter (LPF).

According to the present invention, it is possible to assist the damping and restoration function with a single logic regardless of the vehicle speed by integrating the damping logic and the restoration logic, which were previously operated separately in different areas for each vehicle speed.

In addition, the present invention assists the damping and recovery function with a single logic through integrated parameters, thereby simplifying the control by MDPS by reducing the number of parameters to be tuned.

1 is a functional block diagram of an integrated control device for damping logic and restoration logic by MDPS according to an embodiment of the present invention.
FIG. 2 is a functional block diagram of an actual load estimator of an integrated control device for damping logic and restoration logic by MDPS according to an embodiment of the present invention.
3 is a flowchart illustrating an implementation process of a control method of an integrated control device for damping logic and restoration logic by MDPS according to an embodiment of the present invention.

Hereinafter, an integrated control device for damping logic and restoration logic by MDPS and a method of controlling the same according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, terms to be described below are terms defined in consideration of functions in the present invention, which may vary according to the intention or convention of a user or an operator. Therefore, definitions of these terms should be made based on the contents throughout the specification.

1 is a functional block diagram of an integrated control device for damping logic and restoration logic by MDPS according to an embodiment of the present invention.

FIG. 2 is a functional block diagram of an actual load estimator of an integrated control device for damping logic and restoration logic by MDPS according to an embodiment of the present invention.

1 and 2, the integrated control device of the damping logic and the restoring logic by the MDPS includes a target load determining unit 10, an actual load estimating unit 20, a controller 30, and a filter unit 40. .

The target load determiner 10 determines a target load required for damping and restoring the vehicle based on the steering angle, and determines the size of the target load 12 and the direction of the steering angle based on the magnitude of the steering angle. And a sign determination unit 14 for determining the sign of the target load based on the result.

In detail, the size determiner 12 extracts a load value corresponding to the size of the steering angle from the load table to determine the target load size. Therefore, the size determiner 12 includes a load table storing a load value corresponding to the size of the steering angle, and the load table corresponds to the size of the load as the size of the steering angle increases.

At this time, the load value corresponding to the size of the steering angle stored in the load table can be set differently according to the performance of the MDPS mounted for each vehicle.

The sign determination unit 14 determines the sign of the target load by determining a sign of the target load as a positive number if the steering angle is zero or more and a sign of the target load as a negative number when the steering angle is less than zero. At this time, the steering angle is set to have a value exceeding zero when the steering wheel is rotated in the clockwise direction based on when the steering wheel is in neutral and less than zero when the steering wheel is rotated in the counterclockwise direction.

As described above, the target load determiner 10 determines the size of the target load in the size determiner 12, and determines the sign of the target load in the code determiner 14.

The actual load estimator 20 estimates the actual load based on the column torque and the MDPS output current, and specifically assists the steering force in the torque measured in the column that the driver can detect and the MDPS that the driver cannot detect. In order to sum the output currents, the actual load is estimated.

Therefore, the actual load estimator 20 includes a unit converter 22 that converts A (amperes), which is a unit of current, into Nm (Newton meter), which is a unit of torque, for the sum of torques and currents having different units. .

In addition, since the current generated to assist steering in the MDPS and applied to the column is reflected as the column torque after one sampling period, the actual load estimator 20 uses the column measured in the same sampling period. The actual load is estimated by the sum of the MDPS output current and the column torque measured one cycle before the column torque (Z [n-1]) rather than the sum of the torque and MDPS output current.

The controller 30 outputs an error between the target load determined by the target load determiner 10 and the actual load estimated by the actual load estimator 20, and feeds back the output value to control the difference between the errors. In detail, the input value of the controller 30 is an error between the target load and the actual load, and serves to remove an error occurring in the process of transmitting the error between the loads.

Therefore, the controller 30 outputs an error between the loads passing through the controller 30, and feeds the output value back to the input of the controller 30 to control the difference between the output of the controller 30 and the error to be eliminated. In an embodiment, the controller 30 is a PID (Proportional Integral Derivative) controller.

The filter unit 40 filters the error between the loads output from the controller 30. In particular, the filter unit 40 in the present embodiment includes a low pass filter (LPF), which is included in the output of the controller 30. By filtering the component overshoot or undershoot signal, the error signal generated in the error between the calculated loads is eliminated.

In addition, by adding an error value between the target load and the estimated load filtered by the filter 40 to the control output of the MDPS, a damping and restoration function is performed. In other words, by calculating the load value and the actual load value required for the damping and recovery function in real time, the error between the loads is added to the control output of the MDPS to assist yaw stability and steering resiliency.

3 is a flowchart illustrating an implementation process of a control method of an integrated control device for damping logic and restoration logic by MDPS according to an embodiment of the present invention.

Referring to FIG. 3, a control method for an integrated control device for damping logic and restoration logic by MDPS according to an embodiment of the present invention, first, a controller (not shown) determines a target load based on a steering angle (S10). ).

Specifically, the size determiner 12 determines the size of the target load based on the size of the steering angle, and the code determiner 14 determines the sign of the target load based on the direction of the steering angle.

The size determiner 12 extracts a load value corresponding to the size of the steering angle from the load table to determine the target load size. Therefore, the size determiner 12 includes a load table storing a load value corresponding to the size of the steering angle, and the load table corresponds to the size of the load as the size of the steering angle increases.

The sign determination unit 14 determines the sign of the target load by determining the sign of the target load as + when the steering angle is 0 or more, and by determining the sign of the target load by − when the steering angle is less than 0. At this time, the steering angle is set to have a value exceeding zero when the steering wheel is rotated in the clockwise direction based on when the steering wheel is in neutral and less than zero when the steering wheel is rotated in the counterclockwise direction.

The target load determiner 10 determines the target load by combining the magnitude of the target load determined by the size determiner 12 and the code of the target load determined by the code determiner 14 (S10).

In this case, as an example of combining the magnitude of the target load and the sign of the target load, the code determination unit 14 outputs +1 if the steering angle is 0 or more, and -1 if the steering angle is less than 0. The target load may be determined by multiplying the output of the code determiner 14 by the target load determined by the size determiner 12, but the present exemplary embodiment is not limited thereto.

Next, the controller estimates the actual load based on the column torque and the MDPS output current (S20). In vehicles with MDPS, the steering force is assisted by the MDPS during steering wheel operation, so the total load is divided by the torque measured in the column that the driver can detect and the torque generated by the current output to assist the steering force in the MDPS that the driver cannot detect. Since it is a summation, the actual load is estimated by summing the torque measured at the column torque and the MDPS output current.

Therefore, the actual load estimator 20 converts A (amperes), which is a unit of current, into Nm (Newton meter), which is a unit of torque, through the unit converter 22 to add torques and currents having different units. Sum the column torque and the MDPS output current.

In addition, since the current generated in the MDPS to assist steering and applied to the column is substantially reflected as the column torque after one sampling period, the control unit in this embodiment controls the measured column torque and the MDPS output current in the same sampling period. Instead of summation, the actual load is estimated by the sum of the column torque and the MDPS output current, measured one cycle before the column torque (Z [n-1]).

In the process of determining the target load in the above-described step and estimating the actual load, the target load was first determined and the actual load was estimated later. However, since the present embodiment is not limited thereto, the target load may be determined after estimating the actual load. It is possible.

The controller calculates an error between the target load and the actual load (S30), and calculates an error between the target load determined by the target load determiner 10 and the actual load estimated by the actual load estimator 20 through the controller 30. And outputs the feedback value to control the difference from the error (S40).

In detail, the input value of the controller 30 is an error between the target load and the actual load, and serves to remove an error occurring in the process of transmitting the error between the loads. Therefore, the controller 30 outputs an error between the loads passing through the controller 30, and feeds the output value back to the input of the controller 30 to control the difference between the output of the controller 30 and the error to be eliminated. In an embodiment, the controller 30 is a PID (Proportional Integral Derivative) controller.

Next, the error between the load output from the controller 30 is filtered through the filter unit 40 (S50), in particular, in the present embodiment, the filter unit 40 includes a low pass filter (LPF) to the controller 30 By filtering the overshoot or undershoot signal of the high frequency component included in the output of the signal, the error signal generated in the error between the calculated loads is removed.

The controller performs a damping and restoration function by adding an error value between the target load and the estimated load filtered by the filter unit 40 to the control output of the MDPS. In other words, by calculating the load value and the actual load value required for the damping and recovery function in real time, the error between the loads is added to the control output of the MDPS, thereby assisting yaw stability and steering resiliency.

According to the present embodiment, the damping logic and the restoring logic, which were previously operated separately in different areas according to the vehicle speed band, may be integrated to assist the damping and restoration function with one logic regardless of the vehicle speed.

In addition, the present embodiment assists the damping and restoration function with one logic through integrated parameters, thereby simplifying the control by MDPS by reducing the number of parameters to be tuned.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, I will understand. Accordingly, the true scope of the present invention should be determined by the following claims.

10: target load determiner 12: size determiner
14: code determiner 20: actual load estimation unit
22: unit conversion unit 30: controller
40: filter part

Claims (12)

A target load determination unit to determine a target load based on the steering angle;
An actual load estimator for estimating an actual load based on the column torque and the MDPS output current;
A controller for outputting an error between the target load and the estimated actual load and feeding back an output value to control a difference from the error; And
Filter unit for filtering the output value
Damping logic and restoration logic integrated control device by MDPS comprising a.
The method of claim 1,
The target load determiner may include: a size determiner configured to determine a size of a target load by extracting a load value corresponding to the size of the steering angle from a load table; And
If the steering angle is greater than 0, the sign of the target load is determined to be positive, and if the steering angle is less than 0, a damping logic and restoring logic by MDPS, characterized in that it comprises a sign determining unit for determining the sign of the target load as a negative number. Integrated control unit.
3. The method of claim 2,
The steering angle has a value exceeding zero when the steering wheel is rotated in a clockwise direction based on when the steering wheel is in neutral, and has a value that is less than zero when the steering wheel is rotated in a counterclockwise direction. And integrated control of restoration logic.
The method of claim 1,
And the actual load estimating unit estimates the actual load by the sum of the column torque and the MDPS output current measured one cycle before the column torque.
The method of claim 1,
The controller is a PID (Proportional Integral Derivative) controller, characterized in that the integrated control device of the damping logic and restoration logic by MDPS.
The method of claim 1,
The filter unit is a low pass filter (LPF) characterized in that the integrated control device of the damping logic and restoration logic by MDPS.
Determining a target load based on the steering angle;
Estimating the actual load based on the column torque and the MDPS output current;
Calculating an error between the target load and the actual load;
Outputting an error between the target load and the estimated actual load, and feeding back an output value to control a difference from the error; And
Filter the error between loads
Integrated control method of damping logic and restoration logic by MDPS comprising a.
8. The method of claim 7,
In the step of determining the target load, the load value corresponding to the size of the steering angle is extracted from the load table to determine the size of the target load. If the steering angle is 0 or more, the sign of the target load is determined as a positive number, and the steering angle is determined. If less than 0, the sign of the target load is determined as a negative number, the integrated control method of damping logic and restoration logic by MDPS.
The method of claim 8,
The steering angle has a value exceeding zero when the steering wheel is rotated in a clockwise direction based on when the steering wheel is in neutral, and has a value that is less than zero when the steering wheel is rotated in a counterclockwise direction. Integrated control method of control and restoration logic.
8. The method of claim 7,
And estimating the actual load by the sum of the column torque and the MDPS output current measured one cycle before the column torque in the step of estimating the actual load.
8. The method of claim 7,
The controller is a PID (Proportional Integral Derivative) controller, characterized in that the integrated control method of the damping logic and restoration logic by MDPS.
8. The method of claim 7,
The filter unit is a low pass filter (LPF) characterized in that the integrated control method of the damping logic and the restoration logic by MDPS.

Images