KR102335229B1 - A method for presuming roll angle value of Active Rotary type Stabilizer for vehicles - Google Patents

Abstract

The present invention relates to a method for estimating the roll angle of an active rotation type stabilizer of a vehicle, and more particularly, to a driving determination that determines whether the current vehicle is traveling straight or turning based on detection values provided from a plurality of sensors installed in the vehicle while the vehicle is driving mode, a lateral acceleration calculation mode for calculating a first lateral acceleration value based on the value values provided from the plurality of sensors after the driving determination mode, and a first lateral acceleration value calculated by the lateral acceleration calculation mode; A lateral acceleration estimation mode in which a third lateral acceleration value is calculated using a second lateral acceleration value by reflecting a noise value added according to the driving state of the vehicle, and the third lateral acceleration value calculated by the lateral acceleration estimation mode By including a roll angle estimation mode for estimating the roll angle finally applied to the vehicle body using the driving roll moment value of the vehicle generated from It provides the advantage of providing a comfortable and comfortable riding experience.

Description

{A method for presuming roll angle value of Active Rotary type Stabilizer for vehicles}

The present invention relates to a method for estimating the roll angle of an active rotation type stabilizer of a vehicle, and more particularly, providing greater comfort to the user by estimating the roll angle of the vehicle that is changed according to the driving state of the vehicle and the current vehicle state It relates to a method for estimating the roll angle of an active rotary stabilizer of a vehicle that precisely controls the active rotary stabilizer so that the

In general, vibration generated from the road surface during vehicle driving is primarily mitigated through the wheels (tires) as a means for absorbing them, and the larger vibration transmitted through the wheels is used as a means for absorbing them 2 It is absorbed through the suspension system, giving passengers a more comfortable and comfortable ride.

In addition, this is to minimize the shaking phenomenon in the left and right directions of the vehicle that occurs when the road surface is curved up and down and when the traveling vehicle turns in the left and right directions. ARS: Active Rotary type Stabilizer)) is provided.

Conventionally, by mounting a stabilizer bar made of a single material to extend in the lateral direction of the vehicle body, the rolling of the vehicle body caused by a change in the relative behavior and posture of the left and right suspension devices while the vehicle is driving is prevented by the stabilizer bar itself It was common to stabilize the posture of the vehicle body by relaxing the roll stiffness possessed by the vehicle as a medium.

Such a stabilizer bar is manufactured by cutting a single round bar or pipe material to an appropriate length, molding the cut material to have the shape and rigidity required as a stabilizer bar, and then undergoing processes such as heat treatment, shot peening and painting.

However, the stabilizer bar made of a single material as described above is a passive stabilizer bar, and has the advantage of being easy to manufacture and having a low production cost. Since the roll phenomenon of the vehicle body is controlled using the

Accordingly, in recent years, the use of an ARS equipped with an actuator to adjust the roll stiffness of the stabilizer bar according to the situation is increasing.

The ARS is composed of two half stabilizer bars coupled to both ends of the actuator, and the actuator operates according to the size of the roll generated in the vehicle to adjust the roll stiffness of the stabilizer bar to stabilize the vehicle's posture. has been

1 is a conceptual diagram illustrating a connection state of an actuator and a stabilizer bar in the configuration of an active rotation type stabilizer for a vehicle according to the related art.

As shown in FIG. 1 , in the conventional ARS, a driving unit 60 made of a motor is provided on one side of a housing 55 , and a driving unit 60 is provided on the other side inside the housing 55 . ) is provided with a reduction unit 70 for decelerating the rotational force transmitted from the.

Here, on the outside of the housing 55 to which the driving unit 60 is adjacent, one of the above-described half stabilizer bars (hereinafter, referred to as a 'fixed stabilizer bar 80') surrounds the housing 55 of the motor. It is coupled to the motor cover 85 arranged to support the shaft by welding, and on the outside of the housing 55 adjacent to the reduction part 70, the remaining stabilizer bar (hereinafter, referred to as a 'rotation stabilizer bar 90') is It is connected to the final output end 71 of the reduction unit 70 in a spline gear meshing method to receive a predetermined rotational force.

Although not shown in the drawings, the reduction unit 70 receives rotational force provided from the motor shaft and rotates while the sun gear rotates, and a plurality of planetary gears around the sun gear mesh and revolve, and the plurality of orbiting planetary gears rotate around the sun gear. While simultaneously meshing with the ring gear type housing surrounding the

However, in order to operate the ARS according to the prior art, it is necessary to accurately calculate the body roll angle of the currently traveling vehicle. However, there is a problem in that accurate control of the ARS is difficult because only the roll angle estimated through various sensors installed in the vehicle is uniformly used.

In addition, when the ARS is operated, not only the driving roll moment value generated while the vehicle is driving, but also the acting roll moment value generated due to the operation of the ARS is fully considered, and then more accurate feedback There is a problem in that research to make the control take place in advance.

The present invention has been devised to solve the above technical problem, and by estimating the correct roll angle in consideration of the action roll moment value according to the operation of the active rotation type stabilizer of the vehicle, feedback control of the ARS can be achieved. It is an object of the present invention to provide a method for estimating the roll angle of an active rotating type stabilizer of a vehicle.

A preferred embodiment of the method for estimating the roll angle of the active rotary stabilizer of the vehicle according to the present invention is to determine whether the current vehicle is traveling straight ahead or turning based on detection values provided from a plurality of sensors installed in the vehicle while the vehicle is driving A driving determination mode, a lateral acceleration calculation mode in which a first lateral acceleration value is calculated based on values provided from the plurality of sensors after the driving determination mode, and a first lateral acceleration value calculated by the lateral acceleration calculation mode and a lateral acceleration estimation mode in which a third lateral acceleration value is calculated using a second lateral acceleration value by reflecting a noise value added according to the driving state of the vehicle, and the third lateral acceleration calculated by the lateral acceleration estimation mode The driving roll moment value of the vehicle generated from the acceleration value and the acting roll moment value generated by the operation of the active rotation type stabilizer (hereinafter referred to as 'ARS') are used to finally apply to the vehicle body and a roll angle estimation mode for estimating the roll angle to be used.

Here, in the driving determination mode, when at least one of the lateral acceleration value measured from the lateral acceleration sensor and the steering angle value measured from the steering angle sensor is within a set range, the driving determination mode is determined to be straight-line driving, and the lateral acceleration value and If the steering angle value is out of the set range, it is determined that the vehicle is turning.

In addition, the lateral acceleration estimation mode is characterized in that the second lateral acceleration value is calculated using the following Equation (1).

[Equation (1)]

In addition, in the lateral acceleration estimation mode, the third lateral acceleration is corrected by using an extended Kalman filter or an uncentred Kalman filter for the first lateral acceleration value and the second lateral acceleration value Calculate the value.

In addition, the roll angle estimation mode is characterized in that the traveling roll moment value is calculated from the following Equation (2) using the third lateral acceleration value.

[Equation (2)]

In addition, the roll angle estimation mode estimates an action roll moment value, which is a moment value in the same direction as the traveling roll moment value, from a torque value generated from the ARS in the Y-axis direction of the vehicle.

In addition, the said action roll moment value is calculated using the following formula (3), It is characterized by the above-mentioned.

[Equation (3)]

In addition, the roll angle is characterized in that the traveling roll moment value and the action roll moment value calculated with respect to the X-axis direction of the vehicle are calculated using the following Equation (4).

[Equation (4)]

The method further includes a feedback control mode for controlling the AR using the roll angle estimated by the roll angle estimation mode and the target roll angle of the current vehicle.

According to a preferred embodiment of the method for estimating the roll angle of the active rotary stabilizer for a vehicle according to the present invention, a more accurate roll angle is estimated in consideration of the action roll moment value according to the operation of the active rotary stabilizer, and this is again ARS) can be used as a feedback control mode, so it has the effect of providing a more comfortable and comfortable ride to the user.

1 is a schematic diagram showing a connection state of an actuator and a stabilizer bar in the configuration of an active rotation type stabilizer of a vehicle according to the prior art;
2 is a block diagram showing a preferred embodiment of a method for estimating a roll angle of an active rotation type stabilizer for a vehicle according to the present invention;
3 is a conceptual diagram illustrating a driving determination mode in the configuration of FIG. 2;
4 is a conceptual diagram illustrating a lateral acceleration estimation mode in the configuration of FIG. 2;
5A and 5B are conceptual views illustrating a process of calculating an action roll moment value by an operation of an ARS in the configuration of FIG. 2;
6 is a conceptual diagram illustrating a feedback control mode in the configuration of FIG. 2 .

Hereinafter, a preferred embodiment of a method for estimating a roll angle of an active rotation type stabilizer for a vehicle according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram showing a preferred embodiment of a method for estimating a roll angle of an active rotation type stabilizer for a vehicle according to the present invention, FIG. 3 is a conceptual diagram illustrating a driving determination mode among the configuration of FIG. 2, and FIG. 4 is FIG. It is a conceptual diagram showing the lateral acceleration estimation mode among the configuration of Fig. 5a and 5b are conceptual diagrams showing the calculation process of the action roll moment value by the operation of the ARS in the configuration of Fig. 2, Fig. 6 is Fig. 2 It is a conceptual diagram showing the feedback control mode among the configurations of .

Although not shown in the drawings of the present invention during the description of a preferred embodiment of the present invention, for the configuration shown in the drawings of the prior art, a separate reference number is not given, and the same reference number as the reference number of the prior art is indicated. do it with

A preferred embodiment of the method for estimating the roll angle of the active rotation type stabilizer of the vehicle according to the present invention is, as shown in FIG. A driving determination mode for judging whether traveling or turning driving, a lateral acceleration calculation mode for calculating a first lateral acceleration value based on the values provided from the plurality of sensors after the driving determination mode, and the lateral acceleration calculation mode a lateral acceleration estimation mode for calculating a third lateral acceleration value by using the second lateral acceleration value by reflecting the calculated first lateral acceleration value and a noise value added according to the driving state of the vehicle; The driving roll moment value of the vehicle generated from the third lateral acceleration value calculated by and a roll angle estimation mode for estimating a roll angle finally applied to the vehicle body using

In the case of an existing vehicle to which the active rotary type stabilizer of the vehicle (hereinafter referred to as 'ARS') is not applied, when estimating the roll angle, the existing algorithm (including mathematical expressions, etc.) is used. However, in the case of a vehicle to which ARS is applied, using the driving roll moment value generated by the driving vehicle during turning and the action roll moment value that the ARS acts in response to it, The roll angle should be estimated.

More specifically, the vehicle measures various data directly related to vehicle driving from a plurality of sensors previously installed on the vehicle body while driving. Based on these data, it is possible to determine whether the currently driving vehicle is driving straight or turning. In this case, the data used are lateral acceleration values, yaw rate values, vehicle speed and steering angle, and the like. The data may be continuously measured and provided while the method for estimating the roll angle of the active rotation type stabilizer of the vehicle according to the present invention is performed.

As described above, the driving determination mode is a step of determining whether the vehicle is traveling in a straight line or driving in a turning direction.

If the ARS is driven when the vehicle is driving in a straight line, there is a risk of impairing the driver's riding comfort and the stability of the vehicle while interfering with the movement of the vehicle. For this reason, higher reliability is required for the driving determination mode for judging the current driving state of the vehicle.

Data used for determining whether the driving state of the vehicle is straight driving or turning driving may be a lateral acceleration value and a steering angle among the above-described data. This is because, when the road itself has an inclination, the lateral acceleration value measured by the traveling vehicle is generated in a certain range, but the steering angle does not change at all within a certain range in some cases. In such a case, since the vehicle will be driving straight, the ARS should not be activated.

In this regard, as shown in FIG. 3 , when determining the driving state of the vehicle, if both the lateral acceleration value and the steering angle satisfy the given setting conditions, it is determined that the vehicle is traveling straight ahead, and the given setting conditions are determined by any one of the set conditions. If the values are not satisfied at the same time, it should be judged as turning driving.

In FIG. 3 , Ay is a lateral acceleration value, SWA is a steering wheel angle, and A and B are arbitrarily set conditions. That is, if at least one of the lateral acceleration value and the steering angle is within the range of A and B and satisfies the above-described setting conditions, the current vehicle is determined to be traveling straight ahead, and the lateral acceleration value and the steering angle satisfy both of the above two conditions. If it is not satisfied (or at the same time), that is, if it is out of the range of A and B, it is determined as turning driving.

Meanwhile, in a preferred embodiment of the method for estimating the roll angle of the active rotation type stabilizer of a vehicle according to the present invention, the lateral acceleration calculation mode refers to a lateral acceleration value measured through a plurality of sensors previously installed in the vehicle. Hereinafter, for convenience of description, a lateral acceleration value directly measured through a plurality of sensors will be referred to as a first lateral acceleration value.

In addition, in the lateral acceleration estimation mode, noise (noise) is included in the first lateral acceleration value measured through the above-described plurality of sensors due to internal and external factors. Considering such noise, a more accurate lateral acceleration value ( The lateral acceleration value to be finally obtained is referred to as a 'third lateral acceleration value'). Here, the lateral acceleration value considering noise (hereinafter referred to as a 'second lateral acceleration value') can be calculated through the following equation (1).

[Equation (1)]

Equation (1) is a mathematical model expression of the lateral acceleration value and the yaw rate, where Cf and Cr are the front/rear cornering stiffness of the vehicle, and vx is the vehicle speed. lf and lr are the distances from the center of gravity of the vehicle to the front and rear wheels, Iz is the moment of inertia of the z-axis of the vehicle, and δ is the wheel steering angle, which can be obtained from the actual steering angle and gear ratio.

When the second lateral acceleration value is calculated through Equation (1), the lateral acceleration estimation mode is performed using an extended Kalman filter or an undirected Kalman filter using the first lateral acceleration value and the second lateral acceleration value. The third lateral acceleration value, which is a corrected value, may be calculated using (Uncented Kalman Filter).

5 schematically shows the process of calculating the third lateral acceleration value. In FIG. 5 , Ay is a value obtained through Equation (1) and represents a second lateral acceleration value, and Ay_sen is a value obtained through a plurality of sensors installed in the vehicle and means a first lateral acceleration value.

The first lateral acceleration value Asen and the second lateral acceleration value Ay are lateral acceleration values corrected using an extended Kalman filter (EKF) or an undirected Kalman filter (UKF) method, as shown in FIG. 5 . A third lateral acceleration value can be estimated.

Meanwhile, in the prior art, the roll angle can be estimated using a certain modeling formula so that variables such as the above-described lateral acceleration value and yaw rate are substituted. Actually, the roll angle changes, but the lateral acceleration value and the yaw rate do not change. For this reason, in the embodiment of the present invention, in order to estimate the roll angle of the ARS-applied vehicle, it is not possible to simply substitute a constant modeling formula as in the prior art. shall.

More specifically, in the method for estimating the roll angle of the active rotation type stabilizer for a vehicle according to the present invention, the roll angle estimation mode includes calculating the running roll moment value from the following Equation (2) using the third lateral acceleration value. characterized.

[Equation (2)]

Equation (2) is a formula for calculating the roll moment of the vehicle. Here, in the lateral acceleration estimation mode, ay_com is a Kalman filter (EKF or UKF) using a first lateral acceleration value, which is a lateral acceleration value obtained through a sensor, and a second lateral acceleration value, a lateral acceleration value, which is calculated through Equation (1). ) is the third lateral acceleration value corrected using In addition, m is the mass of the vehicle's spring, and Kof and Kor mean the front/rear wheel roll stiffness of the vehicle. Finally, hs means the vertical distance from the line passing through the front/rear wheel roll center of the vehicle to the center of gravity.

After calculating the running roll moment value using Equation (2), as shown in FIG. 1 , the action roll moment value according to the operation of the ARS should be calculated.

The torque generated by the ARS is an action roll moment value that reduces the overall roll moment of the vehicle while operating in the opposite direction to the driving roll moment value.

However, the torque by the operation of the ARS is generated in the Y-axis of the vehicle, and the driving roll moment value of the vehicle is calculated based on the X-axis direction. For this reason, it is necessary to convert the Y-axis-based torque generated by the ARS into a torque value in the X-axis direction.

Referring to FIGS. 5A and 5B , the torque Ma generated by the ARS can be known through a sensor that measures it, and the overall sizes of the actuator 50 and the stabilizer bars 80 and 90 are already well known. there is a number

As shown in FIG. 5A , the ARS generates torque in the Y-axis direction of the vehicle, and through this, a vertical force such as F is generated at the ends of the fixed stabilizer bar 80 and the rotating stabilizer bar 90 . is created Here, c, which is the bent arm length of the fixed stabilizer bar 80 and the rotating stabilizer bar 90, is measurable, and the size of F can be inferred through a simple formula such as Equation (3). That is, through the force of F generated at the tips of the fixed stabilizer bar 80 and the rotating stabilizer bar 90, the action roll moment value of the ARS compared to the running roll moment value in the X-axis direction of the vehicle is calculated. can be estimated

[Equation (3)]

That is, as shown in FIG. 6 , the left/right lengths (a, b) of the fixed stabilizer bar 80 and the rotating stabilizer bar 90 of the ARS are already known. Finally, it is possible to estimate the action roll moment value generated by the operation of ARS). The acting roll moment value that can be estimated through this process is M_ars, and in the embodiment of the present invention, since the left and right wheels of the front part of the vehicle body and the left and right wheels of the rear part of the vehicle body are respectively provided with ARSs, the Mf_ars of the ARS provided in the front part and Mr_ars of the ARS provided in the rear part of the vehicle body are respectively estimated.

In a preferred embodiment of the method for estimating the roll angle of the active rotation type stabilizer of a vehicle according to the present invention, the roll angle estimation mode uses the driving roll moment value and the acting roll moment value to finally roll the roll of the ARS-driven vehicle. angle can be estimated.

As shown in Equation (4) below, the roll angle can be estimated by adding the action roll moment value generated by the operation of the ARS in Equation (2).

[Equation (4)]

After estimating the roll angle of the final vehicle using Equation (4), as shown in FIGS. 1 and 6 , the estimated roll angle is used for feedback control of the ARS.

The target roll angle is determined by the third lateral acceleration value calculated in the lateral acceleration estimation mode, and as shown in FIG. 6 , a PID controller or TDC (Time Delay Control) using the difference between the estimated roll angle and the target roll angle The feedback control of the ARS can be implemented with the torque and angle calculated using the same control algorithm as the controller.

A preferred embodiment of a method for estimating a roll angle of an active rotation type stabilizer for a vehicle according to the present invention has been described in detail with reference to the accompanying drawings. However, the embodiment of the present invention is not necessarily limited by the above-described preferred embodiment, and it is natural that various modifications and implementations within an equivalent range are possible by those skilled in the art to which the present invention pertains. something to do. Therefore, the true scope of the present invention will be determined by the claims to be described later.

50: actuator 60: drive unit
70: reduction part 80: fixed stabilizer bar
90: rotation stabilizer bar

Claims (9)

a driving determination mode for determining whether the current vehicle is traveling straight ahead or turning based on detection values provided from a plurality of sensors installed in the vehicle while the vehicle is driving;
a lateral acceleration calculation mode for calculating a first lateral acceleration value based on the values provided from the plurality of sensors after the driving determination mode;
The first lateral acceleration value calculated by the lateral acceleration calculation mode and the second lateral acceleration value reflecting the noise value added according to the driving state of the vehicle are combined with an Extended Kalman Filter and an Uncented Kalman Filter ), a lateral acceleration estimation mode for calculating a third lateral acceleration value by correcting it according to any one of;
The driving roll moment value of the vehicle generated from the third lateral acceleration value calculated by the lateral acceleration estimation mode and the active rotation type stabilizer (hereinafter referred to as 'ARS') are generated by the operation and a roll angle estimation mode for estimating a roll angle finally applied to the vehicle body by using an applied roll moment value.
The method according to claim 1,
The driving determination mode is,
If at least one of the lateral acceleration value measured from the lateral acceleration sensor and the steering angle value measured from the steering angle sensor is within the set range, it is determined that the vehicle is traveling straight ahead, and the lateral acceleration value and the steering angle value are out of the set range. In this case, a method of estimating the roll angle of an active rotating stabilizer of a vehicle that is determined to be turning driving.
The method according to claim 1,
The lateral acceleration estimation mode is,
The method for estimating the roll angle of an active rotation type stabilizer for a vehicle, characterized in that the second lateral acceleration value is calculated using the following Equation (1).
[Equation (1)]

delete The method according to claim 1,
The roll angle estimation mode is,
A method of estimating a roll angle of an active rotation type stabilizer of a vehicle for calculating the driving roll moment value from the following Equation (2) using the third lateral acceleration value.
[Equation (2)]

The method according to claim 1,
The roll angle estimation mode is,
A method of estimating a roll angle of an active rotation type stabilizer of a vehicle for estimating an acting roll moment value, which is a moment value in the same direction as the traveling roll moment value, from a torque value generated from the ARS in the Y-axis direction of the vehicle.
7. The method of claim 6,
The action roll moment value is,
A method for estimating the roll angle of an active rotation type stabilizer for a vehicle, characterized in that it is calculated using the following Equation (3).
[Equation (3)]

7. The method according to claim 5 or 6,
The roll angle is
The method for estimating the roll angle of an active rotation type stabilizer for a vehicle, characterized in that the traveling roll moment value and the acting roll moment value calculated based on the X-axis direction of the vehicle are calculated using the following Equation (4).
[Equation (4)]

The method according to claim 1,
and a feedback control mode for controlling the AR using the roll angle estimated by the roll angle estimation mode and the target roll angle of the current vehicle.

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