JPH0741835B2 - Vehicle vibration control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle vibration control device, and more particularly to a vehicle vibration control device suitable for traveling on a curved road at high speed.

[Background of the Invention]

Conventionally, the structure described in JP-A-56-17754 is generally known as a device for reducing vehicle vibration and improving riding comfort. The configuration is such that a fluid pressure actuating mechanism (for example, a telescopic mechanism including a cylinder and a piston) is provided in parallel with a spring provided between a vehicle body and a bogie, the vibration acceleration of the vehicle body is detected, and the detection result is gained by a compensation circuit. The fluid pressure actuating mechanism is controlled by the signal obtained by adjusting the phase to reduce the vibration acceleration of the vehicle body. The compensation circuit is
Integral element Primary advance element (1 + T ₁ S, 1 + T ₃ S), primary delay element [Here, S: Laplace operator, T ₀ , T ₁ , T ₂ , T ₃ , T ₄ : time constant]. The frequency characteristics of gain (output / input) and phase of the compensating circuit are as shown in FIG. 1. The gain is slightly large in the extremely low frequency range of 0.8 Hz or less, and 0.8 Hz to 3 Hz. It is slightly small in the range, becomes large in the vicinity of 10 Hz, and then becomes small in the high frequency range. Corresponding to this, the phase is delayed by 30 degrees near 0.5 Hz, and 0.8 to 2 Hz.
The delay was gradually reduced in the range, advanced slightly in the 2 to 7 Hz range, and gradually increased above 7 Hz. With such characteristics, when there is a peak vibration of the vehicle body in the frequency range of 0.8 to 3 Hz, the vibration can be reduced by about 50% as compared with the case where the vehicle body is not controlled during traveling on a straight road. However, in the curved road as shown in FIG. 2, comprises a very low frequency components a ₂ by lateral acceleration detected by the vehicle body exceeds the centrifugal force in addition to the vibration components a _1, and, of polar low frequency components a ₂ Is larger than the vibration component a ₁ . Further, in the compensation circuit characteristic of FIG. 1, since the gain of the extremely low frequency component of 0.8 Hz or less is larger than the gain for the vibration component of 0.8 to 3 Hz range, the extremely low frequency component is generated in the output of the compensation circuit. The signal of a ₂ is very large and the signal of vibration component a ₁ is small. Therefore, the fluid pressure actuating mechanism may be strongly unilaterally pressed by the signal of the extremely low frequency component a ₂ at the same time when it enters the curved path, and there is a possibility that an impact is likely to occur. Further, since the signal of the vibration component a ₁ is small, the vibration component a ₁ is difficult to control and is not significantly reduced. Thus, a straight road has a sufficient control effect on vibration,
Sufficient consideration was not given to reducing vibration on curved roads.

[Object of the Invention]

An object of the present invention is to provide a vehicle vibration control device capable of exerting a sufficient vibration control effect not only on a straight road but also on a curved road.

[Outline of Invention]

In order to solve the above-mentioned inconvenience, first, a high-pass circuit is provided to reduce the gain in the extremely low frequency range. However, there is a limit to doing this without changing the gain in the vibration component range. Therefore, by subtracting the extremely low frequency waveform from the detected vibration acceleration waveform of the vehicle body, the compensation circuit output consists of only the vibration component. It is possible to do so. By the way, since the detection of the extremely low frequency waveform is required only on a curved road, it is necessary to detect an amount that is extremely small on a straight road and very large on a curved road. What can be considered to obtain the state change amount is the relative lateral displacement between the vehicle body and the bogie, that is, the lateral displacement of the spring in the case of control of lateral vibration. However, the lateral displacement is the third
As shown in the figure, since the maximum values of straight roads and curves are about the same, control is performed at a certain displacement b or more (the displacement b should be as small as possible considering the controllability at the entrance of the curve). As a result, the signal of displacement other than the acceleration is mixed in the control signal on the straight line, the controllability is deteriorated, and the displacements b ₁ and b ₂ (in FIG. 3) on the curved road have the same magnitude. Therefore, there are many unsuitable points such as the detection that the displacement b ₂ component is mainly detected. Therefore, the present invention is characterized in that the state change amount is determined by detecting the absolute inclination angle of the vehicle body and controlling the vibration based on this value. That is, the maximum value of the absolute inclination angle of the car body is
It is about 0.01 rad and about 0.1 rad on a curved road, which is an optimum value with a difference of about 5 to 10 times between a straight furnace and a curved road, and this value enables optimum vibration control.

Example of Invention

An embodiment of the present invention will be described below with reference to FIGS. In FIG. 4, reference numeral 1 is a vehicle body, 2 is a trolley for supporting the vehicle body 1, and 3 is a fluid pressure actuating mechanism provided between the vehicle body 1 and the dolly 2 with the operating direction arranged in the vehicle body left-right direction. Reference numeral 4 is an acceleration detector provided on the vehicle body 1 for detecting a lateral vibration acceleration, and 5 is an absolute inclination angle detector for detecting an absolute inclination angle θ of the vehicle body 1. Reference numeral 6 denotes a compensating circuit which outputs a control command signal for controlling the fluid pressure actuating mechanism 3 with the lateral vibration acceleration detected by the acceleration detector 4 and the absolute tilt angle θ detected by the absolute tilt angle detector 5 as control inputs. Then, it is composed of a first compensation circuit 7, a second compensation circuit 8 and a third compensation circuit 9. The first compensation circuit 7 receives the detection result of the acceleration detector 4 as an input, and integrates it in the same manner as a conventional compensation circuit. Primary advance element (1 + T ₁ S, 1 + T ₃ S), primary delay element It consists of The second compensation circuit 8 is connected to the first compensation circuit 7, and the transfer function Is a high-pass circuit at about 0.1 Hz or higher. [Where K ₁ : proportional constant, T: time constant] The third compensating circuit 9 receives the detection result of the absolute tilt angle detector 5 as an input, and outputs 0.5H of the input.
Low-pass circuit that selects only low-frequency components below z
0, a low-pass circuit 12 that selects only low-frequency components of about 0.5 Hz or less among the outputs of the second compensation circuit 8, and a gain setter as a gain setting unit that adjusts the gains of the outputs of the low-pass circuits 10 and 12. 11 and an output of the gain setting unit 11 and the output of the low-pass circuit 12 are compared, and a comparison circuit 13 that outputs a command to the gain setting unit 11 so that they are equal to each other. Reference numeral 14 denotes an adder / subtractor circuit which is built in the compensating circuit 6 and serves as an adding / subtracting means for adding the output of the third compensating circuit 9 to the output of the second compensating circuit 8 by reversing the sign. Reference numeral 15 is a servo valve that operates according to the output of the compensating circuit 6 and serves as a control unit that controls the pressure of the pressure fluid supplied from the pressure fluid source (not shown) to the fluid pressure operating mechanism 3.

In such a configuration, when the acceleration detector 4 detects the lateral vibration acceleration of the vehicle body 1 and outputs it to the first compensation circuit 7,
It is compensated by the first compensation circuit 7 and the output i ₁ is output. The frequency characteristic of this output i ₁ is 0.5 Hz as shown in Fig. 5 i ₁ /.
In the following, the lower the frequency, the larger the frequency. Then the output i ₁
Is input to the second compensation circuit 8 and a component of about 0.1 Hz or higher is selected by the high pass circuit. As a result, the frequency characteristic of the output i ₂ from the second compensation circuit 8 changes as shown by i ₂ / in FIG. That is, i ₂ / is a gain of the extremely low frequency component of about 0.5 Hz or less, which is made as small as possible within the range where the gain at the frequency of the yawing vibration of the vehicle body 1, for example, 1 Hz does not change. Almost to
A flat characteristic is obtained at 0.5 Hz or less. Accordingly, the waveform of the output i ₂ output i ₁ and the second compensation circuit 8 of the first compensation circuit 7 as shown in FIG. 6, very low frequency component shown i ₂ are each one-dot chain line in comparison with i ₁ C becomes smaller than the extremely low frequency component a ₂ . On the other hand, the output θ of the absolute tilt angle detector 5, that is,
As for i ₃ , as shown in Fig. 7, the extremely low frequency component of 0.5Hz or less has a difference of about 5 to 10 times in magnitude between the straight road and the curved road. Each is compensated by the setter 11 and becomes the output i ₄ . The output i ₄ is composed of only extremely low frequency components of about 0.5 Hz or less, and its magnitude d is almost equal to the magnitude of the extremely low frequency component C of i ₂ shown in FIG. 6 by the comparison circuit 13 and the gain setter 11. Compensated to be equal. Then, in the addition / subtraction circuit 14, the output i ₂ of the second compensation circuit 8 shown in FIG.
Is subtracted from the value obtained by inverting the sign of the output i ₄ of the third compensation circuit shown in FIG. As a result, the output i ₅ of the adder / subtractor circuit 14 has a waveform composed of only the vibration component a _{1 which} contains almost no extremely low frequency component C of about 0.5 Hz or less as shown in FIG. This corresponds to obtaining the frequency characteristic of i ₅ / shown by the dotted line in FIG. The output i ₅ of the compensating circuit 6 thus obtained is transmitted to the servo valve 15, and the servo valve 15 controls the fluid actuating mechanism 3.

With such a configuration, in addition to the conventional compensation of the lateral vibration acceleration of the vehicle body 1, the extremely low frequency component C is obtained from the absolute inclination angle θ of the vehicle body 1 by the third compensation circuit 9 by the value i ₄ Therefore, the output i ₅ finally obtained from the compensation circuit 9 has a value for suppressing only the vibration component a ₁ . Therefore, if the fluid pressure actuating mechanism 3 is controlled by the output i ₅ via the servo valve 15, it will be controlled at a value that does not include the extremely low frequency component due to the excessive centrifugal force acting on the vehicle body 1 during curved traveling. Therefore, a problem such as pressing the vehicle body 1 in one direction due to the excessive centrifugal force does not occur. Further, since the pushing of the vehicle body 1 in one direction is eliminated as described above, the collision between the vehicle body 1 and the lateral movement stopper of the vehicle body 1 can be prevented, and the impact applied to the vehicle body 1 can be greatly reduced.

〔The invention's effect〕

As described above, according to the present invention, it is possible to effectively reduce the vibration of the vehicle body when traveling on a straight road, and prevent problems caused by excess centrifugal force acting on the vehicle body when traveling on a curved road. The ride comfort can be greatly improved by exerting a sufficient vibration control effect during each of the traveling.

[Brief description of drawings]

FIG. 1 is a graph showing gain and phase characteristics of a compensation circuit in a conventional vibration control device, FIG. 2 is a graph showing a vibration acceleration waveform acting on a vehicle body when the vehicle is traveling on a straight road or a curved road, and FIG. FIG. 4 is a graph showing relative lateral displacement between the vehicle body and the bogie on a straight road or a curved road in the vibration control device of FIG. 4, FIG. 4 is a circuit diagram showing an embodiment of the vibration control device according to the present invention, and FIG. Is a graph showing the frequency characteristic of the output of the compensation circuit in the vibration control device of FIG. 4, and FIGS. 6, 7, and 8 are graphs showing the input and output waveforms of the compensation circuit in the vibration control device of FIG. Is. 1 ... Body, 2 ... Bogie, 3 ... Fluid pressure operating mechanism, 4 ...
... acceleration detector, 5 ... absolute tilt angle detector, 6 ... compensation circuit, 7 ... first compensation circuit, 8 ... second compensation circuit, 9 ...
… Third compensation circuit, 14 …… Addition / subtraction circuit, 15 …… Servo valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Higaki 502 Jinritsu-cho, Tsuchiura-shi, Ibaraki Machinery Research Institute, Hiritsu Manufacturing Co., Ltd. Mechanical Research Laboratory (72) Inventor Hideo Takai 794 Higashitoyoi, Kudamatsu City, Yamaguchi Prefecture Stock Company Hitachi Ltd., Kasado Plant

Claims (1)

[Claims] 1. A vehicle body, a bogie for supporting the vehicle body via a spring, a fluid pressure actuating mechanism provided in parallel with the spring, an acceleration detector for detecting a vibration acceleration of the vehicle body, and an absolute inclination angle of the vehicle body. A first compensating circuit including an absolute tilt angle detector for detecting the following, an integral element for compensating the detection result of the acceleration detector, a first-order leading element and a first-order lag element, and an extremely low frequency of the output of the first compensating circuit A second compensation circuit including a high-pass circuit excluding the component, a low-pass circuit for selecting an extremely low frequency component of the detection result of the absolute tilt angle detector, and a third compensation circuit including a gain setting means for adjusting the gain of the output of the low-pass circuit. A circuit, an adding / subtracting means for obtaining a difference between the output of the second compensating circuit and an output of the third compensating circuit, and a pressure of the pressure fluid which is operated by the output of the adding / subtracting means and is supplied to the fluid pressure operating mechanism. Vibration control device for a vehicle, characterized in that consisted with that control unit.