KR100402783B1 - A Method for Determining Torque Applied to Vehicle Dynamic Analysis - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering torque determination method applied to vehicle dynamics analysis. In the conventional dynamics analysis for steering stability analysis of a vehicle, a conventional method of directly applying a steering input to a steering system is a sudden change such as lane change. There is a problem in that it is actually difficult to drive the vehicle along a given path in the transition section and correction of the error is very difficult.

Accordingly, the present invention is to determine the steering torque for minimizing the deviation error when driving the vehicle by determining the steering torque from the target coordinates of the vehicle progress through the proportional-integral-differential controller, the command trace and error calculation reference point which are input elements of the dynamic analysis means Step 1: amplifying the error comparison coordinate (Y) of this error calculation reference point from (X, Y) by the amplifier 10 and determining the first steering torque by adding it to the abscissa (X): this first steering torque From the proportional amplifier (P) to determine the primary second steering torque by the gain set, and through the integrator 14 and the integral amplifier (I) to determine the secondary second steering torque and In addition, the 3rd second steering torque is determined by the gain amount set through the differential amplifier D according to the delay element 16 by the arbitrary sample rate, and the 1, 2, 3rd second steering torque is summed. Third adjustment applied under steering driving conditions It is composed of two steps to determine the scent torque.

Description

A Method for Determining Torque Applied to Vehicle Dynamic Analysis

The present invention relates to a steering torque determination method applied to vehicle dynamics analysis, and more particularly, a lane change for minimizing a deviation error when driving a vehicle by determining steering torque from a target coordinate of vehicle progress through a proportional-integral-differential controller. A steering torque determination method applied to vehicle dynamics analysis in which a simulation is performed.

In general, the performance of the vehicle means various functions of the vehicle as a mechanical assembly, and is classified into power performance, braking performance, steering stability performance and riding performance.

The dual steering stability performances are observed in terms of coordination stability, movement motility and turning performance. The movements that are the targets of the steering stability are generated by steering, and the motion is controlled by steering.

Most of these studies of steering stability are carried out through vehicle dynamics analysis, and one of the objectives of the study of steering stability through vehicle dynamics analysis is to design a vehicle that is easy to control.

In other words, in general, there are a lot of variables that affect the dynamic characteristics of the vehicle, and thus, the design and arrangement of each component is progressing to obtain the optimum dynamic characteristics through the vehicle dynamics analysis by these variables.

Therefore, the vehicle development can be made in the shortest time while minimizing the error of trial and error through the dynamic analysis of the vehicle.

Here, for the controllability of the vehicle controlled by a person in the analysis of the steering stability, technical means for the inherent response parameters of the vehicle itself and the subjective evaluation relationship of the controller itself are applied.

By the way, the conventional adjustment stability analysis has a problem that countless errors and trial and error occur from data to informatization.

This is because the existing method of directly applying the steering input to the steering system is actually difficult to drive the vehicle along a given path in a sudden transition section such as a lane change, and it is very difficult to correct the error.

In more detail, the steering system of the vehicle is divided into a rack-pinion method and a ball-nut method, as is well known. In order to perform J-turning and lane change analysis, the relative displacement and angle are respectively determined according to the steering system. Will be entered.

That is, as shown in FIG. 1, in the conventional case of the vehicle dynamics analysis such as J-turning and lane change, a simulation is performed using the sinusoidal steering input, which is determined to follow the same driving path as the actual vehicle test, for each vehicle as the rotation condition of the steering wheel. After reviewing the subcommittee's performance, the method is repeated according to the satisfaction or dissatisfaction.

However, it is very difficult to drive a vehicle along a given path in a sudden transition section such as a lane change by the conventional method of directly applying a steering input to a steering system.

The reason is that the slippage caused by friction between the road surface and the tire cannot be ignored, and thus the slippage error must be compensated for when the slippage occurs and leaves the given path.

Therefore, the J-turn and lane change analysis by the current steering input method has a number of problems.

First, excessive manpower and time are required in the vehicle driving test, it is difficult to accurately change lanes, the error probability of steering wheel rotation input is high during analysis, and the tuning time for lane change during analysis is increased.

In addition, it was difficult to find the correlation between the test and the analysis result, and the analysis result and the sensitivity analysis were difficult.

Accordingly, the present invention has been made to solve the above problems, the vehicle dynamics to determine the steering torque from the target coordinates of the vehicle progress through the proportional-integral-differential controller to minimize the deviation error during driving of the vehicle The purpose is to provide a steering torque determination method applied to the analysis.

1 is a conceptual diagram showing a conventional steering torque determination method,

2 is a conceptual diagram of a vehicle behavior state for explaining a steering torque determination method according to the present invention;

3 is a conceptual diagram of a proportional-integral-derivative controller showing a steering torque determination method according to the present invention.

-Explanation of symbols for the main parts of the drawings-

10-amplifier, 12,18,20-summer,

14-integrator, 16-delay factor,

I-integral amplifier, P-proportional amplifier,

D-differential amplifier.

DETAILED DESCRIPTION Hereinafter, the most preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention. . Other objects, features, and operational advantages, including the purpose, working effects, and the like of the present invention will become more apparent from the description of the preferred embodiment.

For reference, the embodiments disclosed herein are only presented by selecting the most preferred examples to help those skilled in the art from the various possible examples, the technical spirit of the present invention is not necessarily limited or limited only by this embodiment, Various changes and modifications are possible within the scope without departing from the technical spirit of the present invention, as well as other equivalent embodiments will be found.

Exemplary Drawing FIG. 2 is a conceptual diagram for explaining the present invention, and FIG. 3 is an explanatory diagram showing a steering torque determination method applied to vehicle dynamics analysis according to the present invention.

The present invention amplifies the error comparison coordinates (Y) of the error calculation reference point from the command trajectory and the error calculation reference point (X, Y), which are input elements of the dynamic analysis means, and adds them to the horizontal coordinate (X). Step 1 to determine the first steering torque by:

From the first steering torque, the primary second steering torque is determined by the gain amount set through the proportional amplifier P, and the secondary second steering is determined by the gain amount set through the integrator 14 and the integral amplifier I. In addition to determining the torque, the third and second third steering torques are determined by the gain amount set through the differential amplifier D according to the delay element 16 at an arbitrary sample rate. Steering torque determination method applied to vehicle dynamics analysis consisting of two stages to determine the third steering torque applied to steering driving condition by adding two steering torques.

As described above, the present invention provides a method for determining steering torque for minimizing deviation error through a proportional-integral-derived controller.

To this end, the present invention finally calculates the steering torque calculated according to the target coordinates from the dynamic analysis means including the command trace as the main argument of the steering system and the vehicle through the proportional-integral-differential controller.

For example, in the case of a large-scale bus such as FIG. 2, first, in the case of multi-body dynamics modeling, a vehicle model composed of a steering system, front and rear suspension systems, and a vehicle body using a dynamic analysis and design system (DADS), which is a general-purpose dynamic analysis means, is used. Decide

That is, as an example of multi-body dynamics modeling, if a large bus equipped with an air spring-equipped four-link axle suspension is selected as the applicable vehicle, the front and rear wheel suspensions of the large bus will be provided with two lower links that are responsible for braking and driving forces. It consists of one upper link, fan hard rod for lateral load, anti-roll bar for controlling roll movement, and air spring for maintaining constant vehicle posture and riding comfort according to load change from tolerance to loading. .

The steering system also consists of a steering top and bottom columns, a gearbox, a Pitman arm, front and rear drag links, and an idler arm with a gear ratio of 20.5: 1.

As a result, the total vehicle model of such a large bus is a total of 44 rigid bodies, seven cylindrical joints, nine rotary joints, three spherical joints, seven universal joints, 39 bushings, six springs and a damper. It consists of 26 speed conditions, 1 steering drive condition and 1 relative rotation condition, and the total number of degrees of freedom is 126.

On the other hand, the position control for causing the vehicle to follow the command trajectory, which is a given path, is generally performed at a position A away from the center of gravity CG of the vehicle, and this position is the error calculation reference point (X, Y). do.

It's like getting a driver to look ahead and get information on how to drive the vehicle.

That is, steering torque, which is an important factor among design methods for minimizing the deviation error in consideration of the error comparison coordinate (Y), the abscissa (X), the roll rate and yaw rate, and the speed of the vehicle Can be obtained through the proportional-integral-derivative controller.

Therefore, the error operation reference point (X, Y) becomes the main input function of the proportional-integral-derivative controller, and when explaining the flow of the proportional-integral-differential controller starting from this initial input function, the error comparison coordinate (Y) is It is amplified by the gain amount via the amplifier 10 and then summed in the abscissa X and the summer 12.

Here, the first steering torque is determined, which is amplified by the gain amount of the proportional amplifier P and converted into the primary second steering torque.

In addition, the first steering torque passes through the integrator 14, the integral amplifier I, the delay element 16, and the differential amplifier D.

That is, the first steering torque is amplified by the gain amount of the integral amplifier I through the integrator 14 and converted into the second secondary steering torque, and on the other hand, passes through the delay element 16 at an arbitrary sample rate. The resultant is summed in the summer 18 and then amplified by the gain of the differential amplifier D and converted into third order steering torque.

Finally, the first and second third and second steering torques are summed in the summer 20 to determine the third steering torque, which is applied to the steering joint between the steering upper column and the vehicle body as steering driving conditions.

Therefore, if a given path is determined during lane change or J-turn and the proportional-integral-derivative controller is applied to the entire vehicle model, the proportional gain, integral gain, derivative gain, sample rate, and target coordinates are adjusted in a sharp transition period. The dynamics of the vehicle can be identified easily and accurately.

According to the present invention as described above, it is easy to analyze by changing the gain value of the proportional-integral- derivative in the steering input when analyzing the steering stability of the vehicle model through the proportional-integral-derivative controller.

In addition, it is essential to secure steering input data through the test for steering input in the steering stability analysis of all vehicle models. However, the proportional-integral-differential controller saves manpower and time.

In addition, since the preliminary examination is possible in accordance with the change of the position and the characteristics of the chassis parts, the material cost is reduced.

Claims (1)

From the command trajectory and the error calculation reference point (X, Y), which are the input elements of the dynamic analysis means, the error comparison coordinate (Y) of the error calculation reference point is amplified by the amplifier 10 and summed with the abscissa (X). Step 1: Determine steering torque: From the first steering torque, the first and second steering torques are determined by the gain amount set through the proportional amplifier P, and the second and second steering is set by the gain amount set through the integrator 14 and the integral amplifier I. In addition to determining the torque, the third and second third steering torques are determined by the gain amount set through the differential amplifier D according to the delay element 16 at an arbitrary sample rate. A steering torque determination method applied to a vehicle dynamics analysis consisting of two steps of determining a third steering torque applied to steering driving conditions by adding two steering torques.