KR102033310B1 - Steering return control apparatus of motor driven power steering and method thereof - Google Patents

Abstract

The present invention discloses a steering restoring control apparatus for an electric power steering apparatus and a method thereof. The steering restoring control apparatus of the electric power steering apparatus of the present invention comprises: a restoration time determining unit determining an application time of the auxiliary torque according to the column torque input from the torque sensor; A restoration torque calculation unit for receiving the vehicle speed and the steering angle from the vehicle speed sensor and the steering angle sensor and calculating the restoration torque based on a table according to the vehicle speed and the steering angle; An LKAS processor for processing a request torque input from the lane keeping assist apparatus; And a restoration command calculation unit configured to calculate a restoration command by applying a steering direction input from the steering angle sensor and an application time determined by the restoration time determination unit to any one of the restoration torque and the required torque according to the requested torque input state from the LKAS processor. Characterized in that it comprises a.

Description

Steering Restoration Control Device of Electric Power Steering System and its Method {STEERING RETURN CONTROL APPARATUS OF MOTOR DRIVEN POWER STEERING AND METHOD THEREOF}

The present invention relates to a steering restoring apparatus and a method of the electric power steering apparatus, and more particularly, to the steering restoring in the electric power steering apparatus for performing cooperative control with Lane Keeping Assistance System (LKAS). Steering Restoration Control Device and Electric Method of Electric Power Steering System to Reduce Error Due to Overlap of Auxiliary Torques by Selecting Torque or Restoring Torque According to Requested Torque Input State from Maintenance Aid It is about.

Lane Keeping Assistance System (LKAS) is a system that detects a lane through a sensor and changes the position information of the detected lane into a torque value to prevent lane departure of the vehicle.

For normal operation of the lane keeping assist device, a system for applying the required torque requested by the lane keeping aid to actual vehicle steering is required.

Motor Driven Power Steering (MDPS) enables steering of the vehicle by generating the actual torque generated by the driver when the driver turns the steering wheel.

Therefore, close coordination control with the electric power steering device is necessary for the normal operation of the lane keeping assist device.

That is, the electric power steering system adds the required torque of the lane keeping assist device and the column torque caused by the driver's steering, thereby preventing the vehicle from leaving the lane during the straight driving.

Background art of the present invention is disclosed in Republic of Korea Patent Publication No. 10-2009-0062135 (published on June 17, 2009, the name of the invention: lane maintenance assistance system).

In the case of the electric power steering device, if the driver inputs the steering input when turning the vehicle, and the driver determines that the turning is made to some degree, the driver slowly releases the steering wheel, but the steering wheel returns to the center by the restoring action.

The restoring action of the steering wheel is caused by the self alignment torque of the tire, which is a useful function when the vehicle speed of the vehicle is turning at 5 km / h to 30 km / h.

However, the Self Alignment Torque applied to the steering wheel is not sufficient to return the steering wheel to the center as the steering residual angle remains due to the frictional force of the steering system.

For this reason, in order to completely return the steering wheel to the center, it is inevitably given a function to assist the restoration action.

Therefore, the electric power steering apparatus improves the restoring performance to the center by assisting the restoring action of the steering wheel by applying the restoring torque calculated based on the vehicle speed and the steering angle.

In addition, in the case of an electric power steering apparatus that performs cooperative control with the lane keeping assist device, the vehicle maintains the straight state by applying a required torque for preventing lane departure after the turning is performed in the lane keeping assist device.

After steering is made, as the auxiliary torque for maintaining the center of the steering wheel is generated by both the electric power steering device and the lane keeping auxiliary device, the auxiliary torque is overlapped and an error occurs in the centering of the vehicle without accurate control. There is a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide the required torque input state from the lane maintaining assist device during steering restoration in an electric power steering device performing cooperative control with the lane maintaining assist device. The present invention provides a steering restoring control apparatus and method for an electric power steering apparatus that can reduce steering errors due to superposition of auxiliary torques by selecting a required torque or restoring torque.

The steering restoring control apparatus of the electric power steering apparatus according to the present invention comprises: a restoring time determining unit determining an application time of an auxiliary torque according to a column torque input from a torque sensor; A restoration torque calculation unit for receiving the vehicle speed and the steering angle from the vehicle speed sensor and the steering angle sensor and calculating the restoration torque based on a table according to the vehicle speed and the steering angle; An LKAS processor for processing a request torque input from the lane keeping assist apparatus; And a restoration command calculation unit configured to calculate a restoration command by applying a steering direction input from the steering angle sensor and an application time determined by the restoration time determination unit to any one of the restoration torque and the required torque according to the requested torque input state from the LKAS processing unit. Characterized in that it comprises a.

The present invention is characterized in that it further comprises a restraining limiter for limiting the restoring command calculated by the restoring command calculating unit.

In the present invention, the restoration time determining unit outputs a gain for applying the restoration torque or the required torque according to the column torque, and outputs gain 1 when the column torque is less than the first set value, and the column torque is greater than the second set value. In the case of gain 0, the gain is output so as to be inversely proportional to the column torque in a section in which the column torque is greater than or equal to the first set value and less than or equal to the second set value.

The steering restoring control method of the electric power steering apparatus according to the present invention includes the steps of restoring time determining unit determining the application time of the auxiliary torque according to the column torque input from the torque sensor; Restoring torque calculating unit receives the vehicle speed and the steering angle from the vehicle speed sensor and the steering angle sensor and calculates the restoration torque based on the table according to the vehicle speed and the steering angle; Determining, by the restoration command calculation unit, an input state of the required torque from the LKAS processor; And restoring command calculating unit calculates a restoring command by applying the steering direction input from the steering angle sensor and the application time determined by the restoring time determining unit to any one of the restoring torque and the requesting torque according to the determination result of the input state of the required torque. It characterized by including.

The present invention is characterized in that it further comprises the step of restoring restoring the restraining command calculated by the restoring command calculation unit to output.

In the present invention, the step of determining the application time of the auxiliary torque outputs a gain for applying the restoration torque or the required torque according to the column time recovery unit, the column torque is output gain 1 when the column torque is less than the first set value; The gain is output when the column torque exceeds the second set value, and the gain is output in inverse proportion to the column torque in a section in which the column torque is greater than or equal to the first set value and less than or equal to the second set value.

Steering restoration control device and method of the electric power steering apparatus according to the present invention is the auxiliary torque-in according to the required torque input state from the lane maintenance auxiliary device during steering restoration in the electric power steering device performing cooperative control with the lane maintenance auxiliary device By selecting the required torque or the recovery torque, the steering restoration can be performed, thereby reducing the error due to the overlap of the auxiliary torques and improving the on-center steering feeling.

1 is a block diagram showing a steering restoring control device of an electric power steering apparatus according to an embodiment of the present invention.
2 is a flowchart illustrating a steering restoration control method of an electric power steering apparatus according to an embodiment of the present invention.

Hereinafter, a steering restoration control apparatus and a method of an electric power steering apparatus according to an embodiment of the present invention with reference to the accompanying drawings. In this process, the thickness of the lines or the size of the components shown in the drawings may be exaggerated for clarity and convenience of description.

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.

As shown in FIG. 1, the steering restoring control apparatus for an electric power steering apparatus according to an exemplary embodiment of the present invention includes a torque sensor 10, a vehicle speed sensor 20, a steering angle sensor 30, and a restoring time determining unit 40. And a restoration limiting unit 70, including a restoration torque calculation unit 50, a restoration command calculation unit 60, and a LKAS processing unit 80.

The torque sensor 10 detects the column torque of the steering wheel to determine the steering force of the driver steering the steering wheel (not shown) to determine the application time of the restoration torque.

The vehicle speed sensor 20 detects a vehicle speed of the vehicle.

The steering angle sensor 30 detects a steering direction and a steering angle at which the driver steers the steering wheel.

The restoration time determination unit 40 determines the application time of the request torque or the restoration torque, which is the auxiliary torque, according to the column torque input from the torque sensor 10.

That is, when the driver steers the steering wheel, the application time of the required torque or the restoration torque is determined according to the steering force, and at that point, the column input from the torque sensor 10 through the decoupling can be maximized. Outputs gain for applying auxiliary torque according to torque.

At this time, if the column torque is less than the first set value, the gain 1 is output to maximize the restoration amount. If the column torque is greater than the second set value, the gain 0 is output to prevent the auxiliary torque from being applied. In a section where the column torque is greater than or equal to the first set value and less than or equal to the second set value, the gain is output in inverse proportion to the column torque so that the auxiliary torque is applied according to the column torque.

The restoration torque calculation unit 50 receives the vehicle speed and the steering angle from the vehicle speed sensor 20 and the steering angle sensor 30 and calculates the restoration torque based on a table according to the vehicle speed and the steering angle.

At this time, the table according to the vehicle speed and the steering angle is a map according to the driver's tuning. In the low vehicle speed range, the restoration torque is largely set so that the center restoration of the steering wheel can be performed smoothly.

Also, the large steering angle returns quickly, and when the steering wheel comes to the center portion, it can converge relatively slowly.

The LKAS processing unit 80 processes the required torque applied from the Lane Keeping Assistance System (LKAS) 90 to be applied to the electric power steering apparatus.

The lane keeping assistance device 90 detects lanes through a sensor (not shown) and changes the position information of the detected lanes to torque values to prevent lane departure of the vehicle. The required torque is generated and applied to the LKAS processing unit 80 so as to maintain it.

The restoration command calculation unit 60 selects one of the restoration torque and the required torque according to the requested torque input state from the LKAS processing unit 80, and the steering direction and the restoration time determination unit 40 input from the steering angle sensor 30. The restoration time is calculated by applying the application time determined in the above, so that the auxiliary torque does not overlap.

That is, the restoration command calculation unit 60 applies the application time determined by the restoration time determination unit 40 to the request torque when the request torque is input according to the request torque input state from the LKAS processing unit 80, and the request torque is applied. Is not input, the column torque corresponding to the steering force at which the driver steers the steering wheel by applying the application time determined by the restoration time determination unit 40 to the restoration torque calculated by the restoration torque calculation unit 50 is first. If it is less than the set value, gain 1 is multiplied and the restoring torque, which is the auxiliary torque, or the required torque is output to the maximum, and the restoring command is calculated to maximize the restoring amount. In this case, as the gain 0 is multiplied, the restoration command is calculated so that the required torque, which is the auxiliary torque, or the restoration torque is not applied, and is restored by the driver's steering force.

In addition, the restoring restraining unit 70 can solve the heterogeneity by preventing the restoring restoring when the restoring command calculated by the restoring command calculating unit 60 is calculated to be an unsuitable large value to operate the electric power steering device. Limit the restore command to the set limit value.

As described above, according to the steering restoring control apparatus of the electric power steering apparatus according to the present invention, in the electric power steering apparatus which performs cooperative control with the lane keeping auxiliary apparatus, the required torque input state from the lane keeping auxiliary apparatus during steering restoring is applied. Accordingly, by selecting the required torque, which is the auxiliary torque, or the restoration torque, the steering restoration can be performed, thereby reducing the error due to the overlap of the auxiliary torques and improving the on-center steering feeling.

2 is a flowchart illustrating a steering restoration control method of an electric power steering apparatus according to an embodiment of the present invention.

As shown in FIG. 2, in the steering restoration control method of the electric power steering apparatus, first, the restoration time determination unit 40 determines the application time of the auxiliary torque according to the column torque input from the torque sensor 10 (S10). .

That is, when the driver steers the steering wheel, the application time of the auxiliary torque is determined according to the steering force, and at that time, the column torque input from the torque sensor 10 through the decoupling can be maximized to maximize the recovery amount. Outputs gain for applying auxiliary torque.

At this time, if the column torque is less than the first set value, the gain 1 is outputted to maximize the restoration amount. If the column torque is greater than the second set value, the gain 0 is outputted so that the auxiliary torque is not applied. In a section in which the column torque is greater than or equal to the first set value and less than or equal to the second set value, the gain is output to be inversely proportional to the column torque so that the auxiliary torque is applied.

In addition, the restoration torque calculation unit 50 receives the vehicle speed and the steering angle from the vehicle speed sensor 20 and the steering angle sensor 30 and calculates the restoration torque based on the table according to the vehicle speed and the steering angle (S20).

That is, the restoration torque is calculated based on the table according to the vehicle speed and the steering angle.

At this time, the table according to the vehicle speed and the steering angle is a map according to the driver's tuning. In the low vehicle speed range, the restoration torque is largely set so that the center restoration of the steering wheel can be performed smoothly.

Also, the large steering angle returns quickly, and when the steering wheel comes to the center portion, it can converge relatively slowly.

Thereafter, the restoration command calculation unit 60 determines whether there is an input of the requested torque from the LKAS processing unit 80 (S30).

In order to prevent an error due to overlapping of the request torque input from the LKAS processor 80 and the recovery torque calculated by the recovery torque calculator, this is based on the request torque when the request torque is input from the LKAS processor 80. If the required torque is not input, the restoration command is calculated based on the restoration torque.

Therefore, when the requested torque is input in step S30, the required torque is selected (S40), and when the required torque is not input, the restored torque is selected (S45).

Then, the restoration command calculation unit 60 multiplies the gain for applying the application time determined by the restoration time determination unit 40 to the selected request torque or the restoration torque, and applies the steering direction input from the steering angle sensor 30 to apply the electric power. A restoration command for driving the power steering is calculated (S50).

That is, the restoration command calculation unit 60 applies the application time determined by the restoration time determination unit 40 to the restoration torque calculated by the restoration torque calculation unit 50 or the required torque input by the LKAS processing unit 80. If the column torque according to the steering force to steer the steering wheel is less than the first set value, gain 1 is multiplied, and the restoration command or the required torque is output as the maximum, and the restoration command is calculated to maximize the restoration amount. If the steering force for steering the steering wheel exceeds the second set value, the gain 0 is multiplied to calculate the restoration command so that the restoration torque, which is the auxiliary torque, or the required torque is not applied but is restored by the driver's steering force.

After the restoration command is calculated as described above, if the restoration command calculated by the restoration command calculation unit 60 by the restoration limit unit 70 is calculated to be a large value that is not suitable for the electric power steering device to operate, it inhibits stable restoration. Restoration command is limited to the set limit value to prevent this and resolve the heterogeneity.

That is, it is determined whether the restoration command is out of the limit value (S60). In this case, if the restoring command does not deviate from the limit value, the calculated restoring command is output (S80). However, if the restoring command deviates from the limit value, the restoring command is limited to within the limit value (S70), and this is output (S80).

As described above, according to the steering restoring control method of the electric power steering apparatus according to the present invention, in the electric power steering apparatus which performs cooperative control with the lane keeping auxiliary apparatus, the required torque input state from the lane keeping auxiliary apparatus during steering restoration is applied. Accordingly, by selecting the required torque, which is the auxiliary torque, or the restoration torque, the steering restoration can be performed, thereby reducing the error due to the overlap of the auxiliary torques and improving the on-center steering feeling.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and those skilled in the art to which the art belongs can make various modifications and other equivalent embodiments therefrom. Will understand.

Therefore, the technical protection scope of the present invention will be defined by the claims below.

10: torque sensor 20: vehicle speed sensor
30: steering angle sensor 40: restoring time determination unit
50: restoration torque calculation unit 60: restoration command calculation unit
70: restoring restriction 80: LKAS processing
90 lane keeping aid

Claims (6)

Restoration time determination unit for determining the application time of the auxiliary torque according to the column torque input from the torque sensor;
A restoration torque calculation unit which receives the vehicle speed and the steering angle from the vehicle speed sensor and the steering angle sensor and calculates the restoration torque based on a table according to the vehicle speed and the steering angle;
An LKAS processor for processing a request torque input from the lane keeping assist apparatus; And
A restoration command is calculated by applying the steering direction inputted from the steering angle sensor and the application time determined by the restoration time determination unit to any one of the restoration torque and the requested torque according to the requested torque input state from the LKAS processing unit. A steering restoring control apparatus for an electric power steering apparatus, comprising: a restoring command calculating unit.
2. The steering restoring control apparatus according to claim 1, further comprising a restoring limiting unit for limiting the restoring command calculated by the restoring command calculating unit.
The method of claim 1, wherein the restoration time determination unit outputs a gain for applying the restoration torque or the requested torque according to the column torque, and outputs gain 1 when the column torque is less than a first predetermined value, and the column An output of gain 0 when the torque exceeds the second set value, and outputting the gain such that the gain is inversely proportional to the column torque in a section in which the column torque is greater than or equal to the first set value and less than or equal to the second set value. Steering restoration control.
Determining, by the recovery point determining unit, an application point of the auxiliary torque according to the column torque input from the torque sensor;
Restoring torque calculation unit receives a vehicle speed and a steering angle from a vehicle speed sensor and a steering angle sensor to calculate a restoration torque based on a table according to the vehicle speed and steering angle;
Determining, by the restoration command calculation unit, an input state of the required torque from the LKAS processor; And
The restoration command calculation unit restores by applying the steering direction input from the steering angle sensor and the application time determined by the restoration time determination unit to any one of the restoration torque and the requested torque according to the determination result of the input state of the requested torque. Comprising a command; steering restoration control method of an electric power steering apparatus comprising a.
5. The steering restoring control method according to claim 4, further comprising a restoring limiting unit outputting the restoring instruction calculated by the restoring instruction calculating unit.
The method of claim 4, wherein the determining of the application point of the auxiliary torque comprises:
The restoration time determining unit outputs a gain for applying the restoration torque or the requested torque according to the column torque, and outputs gain 1 when the column torque is less than the first set value, and the column torque is the second set value. And outputting a gain 0 when the gain is exceeded, and outputting the gain so as to be inversely proportional to the column torque in a section in which the column torque is greater than or equal to the first set value and less than or equal to the second set value.

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