KR20030029701A - Method for sensing motion of cars - Google Patents

Abstract

PURPOSE: A method for detecting vehicle motions is provided to detect vertical movements of a vehicle body by installing a vertical direction movement detecting sensor as a relative displacement sensor or an acceleration sensor, and to show optimum performance by controlling vehicle movements without limiting tuning conditions to a fixed surface condition. CONSTITUTION: A vehicle motion detecting method is composed of a vertical direction acceleration sensor(10) detecting the vertical direction acceleration of a vehicle body and supplying the detected information to an Electronic Control Unit(ECU)(20), a vehicle speed sensor(12) detecting and delivering vehicle speed to the ECU, a steering angle sensor(14) detecting and sending traverse movements of the vehicle to the ECU, a brake sensor(16) detecting brake motions, and a throttle position sensor(18) detecting an opening of an air valve in operating an accelerator. The ECU performs optimum outputs of an actuator corresponding to detected signals supplied from all sensors and controls the damping force of a front(22) and rear wheel damper(24).

Description

Vehicle motion detection method {METHOD FOR SENSING MOTION OF CARS}

The present invention relates to a vehicle motion detection method, and more particularly, to a method of determining the behavior of the vehicle body by detecting the movement of the vehicle body in the vertical direction.

In the conventional electronically controlled suspension logic, the road surface is mainly classified into two to five types using an acceleration sensor in order to determine driving conditions of the vehicle. For example, gain control or phase of a control signal may be determined based on determining a driving condition of a vehicle as a normal road, a bad road, a wave road, a bump road, or the like. Phase control, etc., is performed to achieve the optimum actuator output.

However, the actual road surface is too vague to classify into 2 to 5 species. For example, when passing a road under construction, a very large impact is transmitted to the wheels due to the stepped road surface. In this case, the logic classified into 2 to 5 types described above recognizes as a bump and performs control. Therefore, the wrong road surface determination may cause confusion in the design / tuning related to the electronically controlled suspension device, and very much time / human resources are required to obtain a satisfactory performance on all road surfaces.

The present invention has been made in order to improve the above-mentioned shortcomings, by installing a vertical momentum sensing sensor such as an acceleration sensor or a relative displacement sensor in the vehicle body to detect the movement of the vehicle body in the vertical direction to detect the movement of the vehicle body movement The purpose is to provide a method.

According to an aspect of the present invention, there is provided a vehicle suspension system including a sensor for detecting a vertical momentum of a vehicle body, the method including: a first step of detecting a vertical momentum of the vehicle body; Calculating a magnitude and a frequency of a signal corresponding to the vertical momentum sensing; And determining a behavior of the vehicle body as a specific state by mapping the state of the vehicle body corresponding to the magnitude and frequency of the signal.

1 is a block diagram for implementing a vehicle motion detection method according to the present invention;

2 is a flowchart showing step by step an embodiment of a vehicle motion detecting method according to the present invention;

FIG. 3 is a schematic diagram illustrating an embodiment of mapping according to a magnitude and a frequency of a signal performed by the electronic control apparatus shown in FIG. 1. FIG.

<Description of the symbols for the main parts of the drawings>

10: vertical acceleration sensor 12: vehicle speed sensor

14: steering angle sensor 16: brake sensor

18: throttle position sensor 20: electronic control device

22: front wheel damper 24: rear wheel damper

Hereinafter, the embodiment of the present invention will be described in detail with reference to the following drawings.

1 is a block diagram for implementing a vehicle motion detection method according to the present invention, a vertical acceleration sensor 10, vehicle speed sensor 12, steering angle sensor 14, brake sensor (16), throttle position A sensor (Throttle Position Sensor: TPS) 18, an Electronic Control Unit (ECU) 20, a front wheel damper 22, and a rear wheel damper 24.

In the figure, the vertical acceleration sensor 10 detects the vertical acceleration of the vehicle body and provides it to the electronic control device 24. Instead of the vertical acceleration sensor 10, a relative displacement sensor of the vehicle body and the wheel may be used.

The vehicle speed sensor 12 detects a vehicle speed and provides the same to the electronic control apparatus 20.

The steering angle sensor 14 detects the steering angle and provides the steering angle to the electronic control apparatus 20. The steering angle sensor 14 is used to detect the lateral motion of the vehicle.

The brake sensor 16 detects a brake operation and provides the brake control unit 20 to the electronic control apparatus 20.

The throttle position sensor 18 detects the opening degree of the air valve during operation of the accelerator and provides it to the electronic control apparatus 20.

As described above, the type and type of sensor installed in the vehicle are determined according to the system performance or price of the vehicle.

In addition, the vehicle speed sensor 12, the brake sensor 16, and the throttle position sensor 18 may be used to control various conditions.

The electronic control device 20 implements an optimal actuator output in response to the sensing signals provided from the respective sensors 10 to 18 described above. For example, the electronic control apparatus 20 controls the respective damping forces of the front wheel damper 22 and the rear wheel damper 24 in response to the sensing signals provided from the respective sensors 10 to 18, respectively.

Dampers such as the front wheel damper 22 and the rear wheel damper 24 include two-stage to stepless variable dampers, and are generally classified into a step motor type and a solenoid type according to the actuator type. . The damper is designed using a combination of singular and actuator types, taking into account mounting performance, performance and cost.

The logic mounted on the electronic control device 20 is applied to various logic such as adaptive, sky-hook and fuzzy according to the configuration of the sensor and the damper, the driving situation of the vehicle The logic is configured using information input from each sensor to figure out the information.

Figure 2 is a flow chart showing step by step an embodiment of a vehicle motion detection method according to the present invention.

First, the electronic control apparatus 20 receives the vertical acceleration detection signal of the vehicle body from the vertical acceleration sensor 10 and detects the vertical movement amount of the vehicle body (step 2). At this time, the electronic control apparatus 20 removes a direct current (DC) signal from the vertical acceleration detection signal of the vehicle body and passes a dead band filter to pass only a signal of a set value or more so as to pass the vertical momentum of the vehicle body. Detect.

The electronic controller 20 calculates the magnitude of the signal by taking the absolute value of the signal Sdb past the dead band filter (| Sdb |) and passing it through the low pass filter (| Sdb | _Ipf). The electronic control apparatus 20 determines the level of the frequency by comparing the current value and the previous value of the signal past the dead band filter (step 4). At this time, if both the current value and the previous value are "0", the counter "min1" is decremented. If the present value multiplied by the previous value is greater than "0", the counter "min2" is decremented. Otherwise, the counter "max1" is incremented. Here, "min1, min2, max1" is an arbitrary variable used to adjust the increase and decrease of the counter C.

In more detail, if the current value multiplied by the previous value is less than "0", the counter C is incremented. That is, when the signal is converted from negative to positive or positive to negative. If the product of the two values is greater than "0", the counter C is decremented. This is the case where the signal stays in an increased or decreased state. That is, in the case of a low frequency component. If both values are "0", the counter C decreases and converges to "0".

The electronic controller 20 determines the behavior of the vehicle body as a specific state based on mapping the state of the vehicle body as shown in FIG. Step 6). For example, when the frequency C calculated by the counter is small and the signal (Sdb_lpf) passing the low pass filter is small, the vehicle is traveling relatively flat. If the frequency (C) calculated by the counter is small and the signal (┃Sdb┃_lpf) passing through the low pass filter is rather large, the vehicle body is slightly smooth. If the frequency (C) calculated by the counter is small and the signal ('Sdb'_lpf) that has passed the low pass filter is very large, the vehicle body bounces greatly. If the frequency (C) calculated by the counter is large and the signal (┃Sdb┃_lpf) passing the low pass filter is small, a small shock is applied to the vehicle body (small shock). When the frequency (C) calculated by the counter is large and the signal (\ Sdb \ _lpf) passing through the low pass filter is rather large, a large shock is applied to the vehicle body (hard shock).

In FIG. 3, cut_amp1 and cut_amp2 are variables that are arbitrarily increased or decreased according to the designer's intention. In the above example, the state of the vehicle is divided into five, but this is only for understanding, and if necessary, the state of the vehicle may be divided into two or more by increasing or decreasing the number of cut_amps.

In this way, it is possible to grasp the driving state of the vehicle and to increase or decrease the phase of the control output of the electronic control apparatus according to each situation.

As described above, the present invention, by installing a vertical momentum detection sensor such as an acceleration sensor or a relative displacement sensor in the vehicle body to detect the movement of the vehicle body in the vertical direction to determine the behavior of the vehicle body. Therefore, the tuning conditions at the time of development of the electronically controlled suspension device are not limited to the road surface conditions that have been standardized, so that the control is performed according to the behavior of the vehicle body, thereby achieving more optimal performance.

Claims (4)

In a suspension system of a vehicle having a sensor for detecting the vertical momentum of the vehicle body: A first step of sensing a vertical momentum of the vehicle body; Calculating a magnitude and a frequency of a signal corresponding to the vertical momentum sensing; And determining the behavior of the vehicle body as one or more states by mapping the state of the vehicle body corresponding to the magnitude and frequency of the signal. The method of claim 1, wherein the first step of detecting the vertical momentum of the vehicle body by removing a direct current signal from the vehicle's vertical acceleration detection signal and passing through a dead band filter to pass only a signal above a set value. Vehicle motion detection method. 3. The method of claim 2, wherein the second step takes the absolute value of the signal past the dead band filter and passes the low pass filter to calculate the magnitude of the signal, and the current value and the previous value of the signal past the dead band filter. And determining the level of the frequency by comparing the two. The method of claim 3, wherein The third step may include: determining that the vehicle is relatively flat when the frequency is small and the signal passing the low pass filter is small; A 42nd step of determining that the vehicle body is slightly fluttered when the frequency is small and the signal passing the low pass filter is rather large; A fourth step of determining that the vehicle body is largely swung when the frequency is small and the signal passing the low pass filter is very large; A 44th step of determining that a small impact is applied to the vehicle body when the signal having a large frequency and the signal passing the low pass filter is small; And a forty-fifth step of determining that a large impact is applied to the vehicle body when the frequency is large and the signal passing the low pass filter is rather large.