JPH04283125A - Vehicle vibration reducing device - Google Patents

Abstract

PURPOSE:To sufficiently reduce vehicle vibration level which a person can feel. CONSTITUTION:Vibration of vehicle is reduced by vibrating a radiator 1 by a vibration application device 6. Sensitive vibration level is determined based on the results of detection of each vibration detection means 100 which is provided at a plural number of target positions on vehicle and a weighted coefficient of each target position which is obtained by a weighted coefficient calculating means 101 in accordance with number of revolutions of an engine. When the sensitive vibration level is at a high target position, it is possible to reduce actual vibration level greatly.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle vibration reduction device.

0002

2. Description of the Related Art A vehicle vibration reduction device that reduces vehicle vibration by transmitting the vibration of an exciter to a radiator and causing the radiator to vibrate is provided with an acceleration sensor for detecting vehicle vibration. A vehicle vibration reduction device that performs feedback control of a vibrator based on the detection results of this acceleration sensor is known (
(Refer to Utility Model Application Publication No. 60-88141).

0003

[Problems to be Solved by the Invention] However, in order to reduce vibrations at a plurality of vibration reduction target positions on a vehicle, an acceleration sensor is provided at each target position, and based on the output of each acceleration sensor, the actual If the vibration exciter is controlled so as to uniformly reduce the vibration level of the vibration, the following problems will occur.

[0004] That is, at each target position, the degree of influence that the actual vibration level has on the sensory vibration level felt by humans (hereinafter referred to as "sensory vibration level") is different, and this influence varies depending on the engine speed. Therefore, if the actual vibration level is uniformly reduced at each target position, there will be target positions where the sensory vibration level cannot be sufficiently reduced. As a result, a problem arises in that the level of vibration felt by humans cannot be sufficiently reduced.

[0005]

[Means for Solving the Problems] In order to solve the above problems, according to the present invention, as shown in the configuration diagram of the invention in FIG. In a vehicle vibration reduction device that reduces vehicle vibration by vibrating a body 1, a plurality of vibration reduction devices are provided at a plurality of vibration reduction target positions on the vehicle to detect the actual vibration level at the target position. Each target position is determined from the detection means 100, the weighting coefficient calculating means 101, which calculates each weighting coefficient corresponding to each target position according to the engine speed, and each detection result of each vibration detection means 100, and each corresponding weighting coefficient. a sensory vibration level calculation means 102 for calculating the sensory vibration level at the target position; and an exciter control means 10 for controlling the vibrator 6 so that the higher the sensory vibration level at the target position, the greater the reduction in the actual vibration level.
3.

[0006]

[Operation] A perceptual vibration level is calculated from each detection result of each vibration detection means and each corresponding weighting coefficient determined according to the engine speed. The higher the target position has this sensory vibration level, the more the actual vibration level is reduced.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 2, the upper end of a radiator 1, which is a mass body, is supported by an upper support 3 via a support 2 made of rubber, and the radiator 1 is movable up and down. Lower tank 4 at the bottom of radiator 1
The side surface of the case 7 of the vibrator 6 is connected via the rubber bush 5.
is connected to. A support piston 8 at the lower end of the vibrator 6 is fixed on a center member 9. Center member 9 is
It is connected to a body frame to which an internal combustion engine (not shown) is attached.

The case 7 of the vibrator 6 is movable relative to the support piston 8. A piezoelectric element 10 is disposed within the case 7, and the piezoelectric element 10 expands and contracts depending on the level of applied voltage. Therefore, by controlling the voltage applied to the piezoelectric element 10, the case 7 of the vibrator 6 can be caused to vibrate.

The electronic control unit 20 is composed of a digital computer, and includes a ROM (read only memory) 22, a RAM (random access memory) 23, a CPU (microprocessor) 24, and an input port 25, which are interconnected by a bidirectional bus 21. and an output port 26.

Steering sensor 1 which is an acceleration sensor
1 is attached to a steering shaft near the steering wheel (not shown). A detection signal from the steering sensor 11 indicating the vibration acceleration of the steering wheel is input to the input port 25 via the A/D converter 27 . A floor sensor 12, which is an acceleration sensor, is attached to a floor in the vehicle interior (not shown). A detection signal from the floor sensor 12 indicating the vibration acceleration of the floor is input to the input port 25 via the A/D converter 28 . In this embodiment, the steering wheel and the floor are the vibration reduction target positions. A crank angle sensor 13 for detecting engine speed is connected to the input port 25.

On the other hand, the output port 26 is connected to the piezoelectric element 10 of the vibrator 6 via a drive circuit 29.

In order to cause the radiator 1 to generate vibrations that offset the vibrations generated in the vehicle, the piezoelectric element 10 of the vibrator 6 receives a detection signal from the steering sensor 11, a detection signal from the floor sensor 12, and a detection signal from the floor sensor 12. A voltage having a phase and a voltage value depending on the engine speed is applied. This causes the vibrator 6 to vibrate the radiator 1 so as to offset the vibrations of the vehicle.

By the way, at each target position where the vibration level is to be reduced, that is, in this embodiment, at the steering wheel and the floor, the degree of influence of the actual vibration level on the sensory vibration level felt by the person is determined. The degree of influence varies depending on the engine speed. For this reason, a problem arises in that even if the actual vibration level in the steering wheel and the floor are uniformly reduced, the perceived vibration level in either one cannot be sufficiently reduced.

FIG. 3 shows the vibration exciter 6 during idling operation.
The routine for controlling the is shown below. This routine is executed by interrupts at regular intervals.

Referring to FIG. 3, first, in step 40, the detection signal xs of the steering sensor 11, the detection signal xF of the floor sensor 12, and the engine speed N are read. Next, in step 41, it is determined whether the engine speed N has changed. If it is determined that the engine speed N has changed, the process proceeds to step 42, where the optimum phase initial value φi and optimum voltage initial value Vi are read from the map based on the engine speed N.

The initial value φi of the optimal phase and the initial value Vi of the optimal voltage are stored in advance in the ROM 22 (see FIG. 2) as a map based on the engine speed N, as shown in FIG.

Referring again to FIG. 3, in step 43, the weighting coefficient an at the mounting position of the steering sensor 11 and the weighting coefficient bn at the mounting position of the floor sensor 12 are read from the map based on the engine speed N. These weighting factors an, bn indicate the influence of the actual vibration level at each location on the sensory vibration level. Therefore, if the weighting factor is small, the sensory vibration level will be low even if the actual vibration level is high, and conversely, if the weighting factor is large, the sensory vibration level will be high even if the actual vibration level is low. The weighting coefficients an and bn are determined so that their sum becomes 1.

The weighting coefficients an, bn change depending on the engine speed. Therefore, weighting factors an,b
n is stored in advance in the ROM 22 (see FIG. 2) as a map based on the engine speed N, as shown in FIG.

In step 44, Y obtained from the following equation
The initial values φi and Vi are changed so that the vibration exciter 6 is feedback-controlled. Y=an xs 2 +bn xF 2 where xS
The reason why and xF are squared is to unify all of these values to positive values since xS and xF take negative values. Therefore, Y=an |xs |+bn |x
It may also be obtained as F |. xS and xF indicate the actual vibration levels of the steering wheel and the floor, respectively, and an xs 2 and bn xF 2 indicate the sensory vibration levels of the steering wheel and the floor, respectively.

In order to explain the operation of this embodiment in an easy-to-understand manner, numerical examples will be used as follows. for example,
Suppose that an = 0.2 and bn = 0.8 are determined at a certain rotation speed. At this time, Y is expressed by the following formula. Y=0.2xs 2 +0.8xF 2 In this case, if xs indicating the actual vibration level of the steering wheel is, for example, 10, and xF indicating the actual vibration level of the floor is, for example, 1, then this represents the sensory vibration level of the steering wheel. an xs 2 is 20, and bn xF 2 , which indicates the sensory vibration level of the floor, is 0.8. In this case, in order to minimize Y, the actual vibration level xs in the steering wheel, where the sensory vibration level is high, is
This will result in a greater reduction.

On the other hand, xS and xF are both 1, for example.
0, an xs 2 is 20, bn x
F 2 will be 80. In order to minimize Y in this case, the actual vibration level xF on the floor where the sensory vibration level is high is reduced to a greater extent than the actual vibration level at the steering wheel where the sensory vibration level is low. That is, even if the actual vibration levels xs, xF are the same, if one sensory vibration level is higher than the other, one actual vibration level will be reduced more than the other.

If it is determined in step 41 that N does not change, steps 42 and 43 are skipped and the process jumps to step 44. Step 4
4, the vibrator 6 is controlled by changing the phase φ and the voltage V so that Y is minimized.

As described above, according to this embodiment, the actual vibration level at the target position where the sensory vibration level is high is
The sensory vibration level can be sufficiently reduced so as to be more significantly reduced than the actual vibration level at the target position where the sensory vibration level is low.

Furthermore, since the sensory vibration level is determined based on the weighting coefficients an, bn determined according to the engine speed, the sensory vibration level can be sufficiently reduced even if the engine speed changes. You can force it.

[0025] In this embodiment, the reduction of the perceptual vibration level during idling operation has been described, but the present invention can also be applied to other operating conditions.

[0026]

[Effects of the Invention] The level of vibration felt by humans can be sufficiently reduced.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of the present invention.

FIG. 2 is an overall view of the vehicle vibration reduction device of the present invention.

FIG. 3 is a flowchart for controlling a vibrator.

FIG. 4 is a map of the initial value φi of the optimum phase and the initial value Vi of the optimum voltage.

FIG. 5 is a map of weighting coefficients an, bn.

[Explanation of symbols]

1...Radiator 6... Vibrator 11...Steering sensor 12...Floor sensor

Claims (1)

[Claims] Claim 1: A vehicle vibration reduction device that reduces vibration of a vehicle by transmitting vibrations from a vibration exciter to a mass body and causing the mass body to vibrate. a plurality of vibration detection means for detecting the actual vibration level of the target position, a weighting coefficient calculation means for calculating each weighting coefficient corresponding to each target position according to the engine rotation speed, and each of the vibration detection means. sensory vibration level calculating means for calculating a sensory vibration level at each of the target positions from each detection result of the means and each of the corresponding weighting coefficients; and a vibration exciter control means for controlling the vibration exciter so as to significantly reduce the vibration of the vehicle.