KR102548224B1 - Active roll stabilizer system and method thereof - Google Patents

Abstract

The present invention relates to an active roll stabilizer system and method capable of accurately measuring torque transmitted from a torque sensor to a stabilizer and adaptively compensating for an external impact.
A control method of an active roll stabilizer according to an embodiment of the present invention includes the steps of detecting motion information of a motor, calculating an alpha value for determining response characteristics based on the motion information, and the calculated alpha value. Selecting one of IP controller (integral-proportional controller), PI controller (proportional-integral controller), and IP-PI controller as a compensation module based on It includes steps to

Description

Active roll stabilizer system and method {ACTIVE ROLL STABILIZER SYSTEM AND METHOD THEREOF}

The present invention relates to an active roll stabilizer, and more particularly, to an active roll stabilizer system and method capable of accurately measuring torque transmitted from a torque sensor to the stabilizer and adaptively compensating for an external impact.

A stabilizing device is a device for improving the stability of a vehicle body when turning or rolling a vehicle. The stabilizing device rotates a stabilizer formed in the longitudinal direction using an actuator when the left and right wheels of the vehicle move up and down to generate a restoring force, thereby reducing the inclination of the vehicle body.

However, since the active roll stabilizer according to the prior art can only be controlled on/off, there is a problem in that control suitable for the driver's taste or characteristics cannot be performed. Therefore, the driver's characteristics, driving habits, and vehicle behavior do not correspond to each other, causing inconvenience to the driver in many cases.

Republic of Korea Patent Publication No.: 10-1998-0056931 (active roll control device for vehicles)

In order to solve the above problems, an active roll stabilizer system and method capable of providing more advanced roll stabilization by accurately measuring the torque transmitted from the torque sensor to the stabilizer and adaptively compensating for the external shock has been developed. making it a technical challenge.

In addition to the technical problems of the present invention mentioned above, other features and advantages of the present invention will be described below, or will be clearly understood by those skilled in the art from such description and description.

In order to achieve the above object, a control method of an active roll stabilizer according to an embodiment of the present invention includes the steps of detecting motion information of a motor, and calculating an alpha value for determining response characteristics based on the motion information. and selecting one of an IP controller (integral-proportional controller), a PI controller (proportional-integral controller), and an IP-PI controller as a compensation module based on the calculated alpha value, and based on the selected compensation module and compensating for the drive control value of the motor.

In the method for controlling an active roll stabilizer according to an embodiment of the present invention, the alpha value has a value of 0, 1 or between 0 and 1 in proportion to a reference measurement value detected from the motor.

In the method for controlling an active roll stabilizer according to an embodiment of the present invention, when the alpha value is 0, the IP controller is selected as the compensation module, and when the alpha value is 1, the PI controller is selected as the compensation module. and selecting the IP-PI controller as the compensation module when the alpha value is between 0 and 1.

An active roll stabilizer system according to an embodiment of the present invention includes a detection unit that detects motion information of a motor, a determination unit that calculates an alpha value for determining response characteristics based on the motion information, and a compensation unit that selects one of an IP controller (integral-proportional controller), a PI controller (proportional-integral controller), and an IP-PI controller as a compensation module based on the selected compensation module, and a driving control value of the motor based on the selected compensation module. and a drive controller that compensates for

In the active roll stabilizer system according to an embodiment of the present invention, the alpha value has a value of 0, 1 or between 0 and 1 in proportion to a reference measurement value detected from the motor.

The compensation unit of the active roll stabilizer system according to an embodiment of the present invention selects the IP controller as the compensation module when the alpha value is 0, and selects the PI controller as the compensation module when the alpha value is 1. and if the alpha value is between 0 and 1, the IP-PI controller is selected as the compensation module.

The method for controlling an active roll stabilizer according to an embodiment of the present invention can provide roll stabilization with more advanced performance by accurately measuring torque transmitted to the stabilizer and adaptively compensating for an external impact.

In addition, other features and advantages of the present invention may be newly identified through the embodiments of the present invention.

1 is a schematic block diagram of an active roll stabilizer system according to an embodiment of the present invention.
2 is a characteristic graph exemplarily illustrating a change in a pressing amount and torque transmitted to a damper.
FIG. 3 is a block diagram of the compensation unit shown in FIG. 1 .
4 is a schematic equation block diagram of an ARS system according to an embodiment of the present invention.
5 is a graph illustrating response characteristics according to alpha values.
6 is an example of a wheel for explaining the effect of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In order to clearly describe the present invention, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification.

Throughout the specification, when a part is said to be "connected" to another part, this includes not only the case where it is "directly connected" but also the case where it is "electrically connected" with another element interposed therebetween. . In addition, when a certain component is said to "include", this means that it may further include other components without excluding other components unless otherwise stated.

When a part is referred to as being “on” another part, it may be directly on top of the other part or may have other parts in between. In contrast, when a part is said to be “directly on” another part, there are no other parts in between.

Terms such as first, second and third are used to describe, but are not limited to, various parts, components, regions, layers and/or sections. These terms are only used to distinguish one part, component, region, layer or section from another part, component, region, layer or section. Accordingly, a first part, component, region, layer or section described below may be referred to as a second part, component, region, layer or section without departing from the scope of the present invention.

The terminology used herein is only for referring to specific embodiments and is not intended to limit the present invention. As used herein, the singular forms also include the plural forms unless the phrases clearly indicate the opposite. The meaning of "comprising" as used herein specifies particular characteristics, regions, integers, steps, operations, elements and/or components, and the presence or absence of other characteristics, regions, integers, steps, operations, elements and/or components. Additions are not excluded.

Terms indicating relative space such as “below” and “above” may be used to more easily describe the relationship of one part to another shown in the drawings. These terms are intended to include other meanings or operations of the device in use with the meaning intended in the drawings. For example, if the device in the figures is turned over, certain parts described as being “below” other parts will be described as being “above” the other parts. Thus, the exemplary term "below" includes both directions above and below. The device may rotate 90 degrees or other angles, and terms denoting relative space are interpreted accordingly.

Although not defined differently, all terms including technical terms and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs. Terms defined in commonly used dictionaries are additionally interpreted as having meanings consistent with related technical literature and currently disclosed content, and are not interpreted in ideal or very formal meanings unless defined.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein.

1 is a schematic block diagram of an active roll stabilizer (hereinafter referred to as ARS) system according to an embodiment of the present invention.

Referring to FIG. 1 , the ARS system according to an embodiment of the present invention includes a driving controller 101, a driving unit 103, a detection unit 105, and a compensating unit 107.

The driving controller 101 sets a target current value based on torque, vehicle speed, etc., and outputs a control signal to the driving unit 103 to drive the motor 111 . For example, the drive controller 101 receives torque information and operation information of the motor 111 from the detection unit 105, sets a target current value based on the received information, and sets the target current value for the drive unit 103. A control signal may be output so as to be driven by matching the current value.

The driving unit 103 drives the motor 111 in response to a control signal provided from the driving controller 101 .

The detection unit 105 detects motion information of the motor 111 . For example, the detection unit 105 senses and outputs a detection value detected by the motor 111 driven according to the target current value, for example, a feedback current value. The detector 105 may include a current sensor that detects a current in a winding or circuit of the motor 111 .

The compensator 107 calculates an error obtained by comparing the target current value and the feedback current value, compensates for the calculated error, and supplies the compensated error to the driving controller 101 . Accordingly, the driving controller 101 continuously controls the operation of the motor 111 based on the target current value compensated for the error.

In the illustrated example, the compensation contact 109 is preferably formed at the front end of the drive controller 101 . This is to reduce sudden signal changes formed in the signal path provided at the front end of the drive controller 101 when the compensation value calculated by the compensator 107 is applied to the target current value. According to the present invention, ripple can be reduced when controlling the driving of the motor 111 through the driving controller 101 .

The ARS system of the present invention receives motion information of a torque sensor and a motor for torque control, and performs torque and speed control accordingly. Meanwhile, inside an actuator connecting left and right wheels of a vehicle, a damper may be used at a middle portion to provide effects such as gear damage prevention and ride comfort improvement.

Looking at the graph of the pressing amount and torque transmitted to the damper in the ARS system of the present invention is as follows.

2 is a characteristic graph exemplarily illustrating a change in a pressing amount and torque transmitted to a damper. In FIG. 2, the pressing amount is expressed as an angle, that is, Angle.

Referring to FIG. 2 , it can be seen that torque transmission is relatively small at the initial stage of driving the motor 111 and increases as the pressing amount gradually increases. According to this angle-torque curve, it can be seen that a large amount of motor rotation is required to generate torque in the initial section.

When the ARS system targeting a specific torque drives on a road with a target torque of 0 (ie, a normal straight road with a steering angle of 0 degrees), an impact is transmitted to the stabilizer bar according to the roughness of the road surface. In this case, a torque of approximately ±1 to 5 Nm may be applied to the sensor. At this time, the actuator performs a motor operation to compensate for this. According to the illustrated graph, the actuator performs a motor operation for compensation of about ±3 degrees.

Meanwhile, on a normal straight road where control of the motor 111 is not required, the motor 111 must be controlled at a speed exceeding several thousand rpm. However, controlling the motor at a speed exceeding several thousand rpm is not easy due to mechanical inertia and frictional force of the motor 111 . In addition, a problem of an increase in battery current loss due to the control of the motor 111 may occur.

The ARS control method according to an embodiment of the present invention can solve the above problems. Hereinafter, embodiments of the present invention will be described in more detail.

FIG. 3 is a block diagram of the compensation unit shown in FIG. 1 .

Referring to FIG. 3 , the compensation unit includes a determination unit, an IP controller, a PI controller, and a PI-IP controller.

The compensation unit 107 is configured to compensate for the driving control value of the motor by using an error between an output value (feedback current) and a set value (target current value) using an arithmetic method such as integration, differentiation, or integral proportional. For example, the compensation unit 107 may include a proportional term, an integral term, and a derivative term.

The proportional term acts as a control proportional to the size of the error value in the current state.

The integral term acts to cancel the steady-state error.

The derivative term reduces overshoot and improves stability by braking sudden changes in the output value.

Since the IP controller 203 (integral-proportional controller) and the PI controller 205 (proportional-integral controller) are known technologies, a detailed description thereof will be omitted.

The determination unit 201 receives a detection value detected by the motor 11 from the detection unit 105, for example, a feedback current value, and calculates an alpha value that determines the response characteristics of the ARS system based on the received feedback detection value. . The alpha value is a value for setting a time constant for controlling driving of the motor 111, and the response speed at which the motor 111 operates is controlled according to the alpha value. Here, the alpha value may be a value proportional to an error value (reference measurement value). For example, the alpha value may have values of 0 and 1 in proportion to the reference measurement value. Also, the alpha value may have a value between 0 and 1.

In particular, the determination unit 201 of the present invention determines which one of the IP controller 203 (integral-proportional controller), the PI controller 205 (proportion-integral controller), and the IP-PI controller 207 based on the calculated alpha value. One can be selected as a compensation module. For example, the determination unit 201 compensates the drive control value of the motor 111 using the IP controller 203 when the calculated alpha value is 0. In addition, the determination unit 201 compensates for the drive control value of the motor 111 using the PI controller 205 when the alpha value is 1. In addition, the determination unit 201 compensates for the drive control value of the motor 111 using the IP-PI controller when the alpha value is between 0 and 1.

The PI controller 205 has overshoot and undershoot to secure fast response. In a system with a large load, this over/undershoot acts small, but in a small or no load, the over/undershoot becomes large, so as described above, energy consumption will increase.

Since the IP controller 203 has a small time constant and a relatively small overshoot, it does not quickly follow the system under no-load or no-load conditions.

The IP-PI controller 207 quickly performs control by performing PI control when an error value (reference measurement value) is large during control under a small or no load condition. In the case of a normal state with a small error value, control can be performed relatively slowly using the characteristics of the IP controller 203. Therefore, it is possible to reduce control noise in a stop or normal driving state of the vehicle, and rapidly control when the target control value fluctuates rapidly.

Since the PI-IP controller 207 manages two P gains, it has the advantage of being able to separately adjust the P gains according to the control situation.

Such an ARS system according to an embodiment of the present invention may be implemented with a formula block diagram as shown in FIG. 4 .

4 is a schematic equation block diagram of an ARS system according to an embodiment of the present invention, and FIG. 5 is a graph illustrating response characteristics according to alpha values.

An ARS system according to an embodiment of the present invention may be configured as shown in FIG. 4 . In addition, the alpha value of the parameter determining the time constant in FIG. 4 may be as shown in FIG. 5 .

Referring to FIG. 4 , as shown in Equation 1, response characteristics to the command speed may be varied by varying the alpha value.

Also, as shown in Equation 2, even if the alpha value is varied, the response characteristics to external impact are not affected.

In this way, the ARS control method of the present invention performs PI control when the error value (reference measurement value) is relatively large, thereby performing control quickly. And, in the case of a normal state with a small error value, control can be performed relatively slowly by using the characteristics of the IP controller 203. Therefore, it is possible to reduce control noise in a stop or normal driving state of the vehicle, and rapidly control when the target control value fluctuates rapidly.

6 is an example of a wheel for explaining the effect of the present invention.

Referring to FIG. 6 , in the case of estimating and controlling non-uniform torque rising from the road surface while the vehicle is driving, the control is performed at thousands of rpm or more to control the fast-changing torque. At this time, the present invention has an effect of reducing noise by filtering noise while maintaining control performance using the PI-IP controller 207.

If, in FIG. 6, in a situation where the interval is narrowed due to overshoot in the direction ①, when the instantaneous controller operates in the direction ②, the response of the system slows down by the corresponding angle. In this case, the present invention has an effect of uniformizing the control responsiveness in directions ① or ② by performing control near the origin using the IP controller 203 in a steady state.

Those skilled in the art to which the present invention pertains should understand that the embodiments described above are illustrative in all respects and not limiting, since the present invention can be embodied in other specific forms without changing the technical spirit or essential characteristics thereof. only do The scope of the present invention is indicated by the claims to be described later rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be construed as being included in the scope of the present invention. .

101: drive controller
103: driving unit
105: detection unit
107: compensation unit
111: motor

Claims (6)

Detecting motion information of the motor;
Calculating an alpha value for determining response characteristics based on the motion information;
selecting one of an IP controller (integral-proportional controller), a PI controller (proportional-integral controller), and an IP-PI controller as a compensation module based on the calculated alpha value; and
Compensating the drive control value of the motor based on the selected compensation module; Including,
The alpha value is,
Has a value of 0, 1 or between 0 and 1 in proportion to the reference measurement value detected from the motor,
When the alpha value is 0, select the IP controller as the compensation module;
When the alpha value is 1, the PI controller is selected as the compensation module;
and selecting the IP-PI controller as the compensation module when the alpha value is between 0 and 1. delete delete a detector for detecting motion information of the motor;
a determination unit calculating an alpha value for determining response characteristics based on the motion information;
a compensation unit that selects one of an IP controller (integral-proportional controller), a PI controller (proportional-integral controller), and an IP-PI controller as a compensation module based on the calculated alpha value; and
A drive controller that compensates for a drive control value of a motor based on the selected compensation module;
The alpha value is,
Has a value of 0, 1 or between 0 and 1 in proportion to the reference measurement value detected from the motor,
The compensation part,
When the alpha value is 0, select the IP controller as the compensation module;
When the alpha value is 1, the PI controller is selected as the compensation module;
Active roll stabilizer system for selecting the IP-PI controller as the compensation module when the alpha value is between 0 and 1. delete delete

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