JPH06156037A - Control gain adjusting device for suspension - Google Patents

Abstract

(57) [Summary] [Purpose] Accurately evaluate the vibrations related to the sensation of the occupant,
Furthermore, to provide a suspension control gain adjusting device that remarkably improves the riding comfort by optimally controlling the characteristics of the suspension in accordance with an evaluation standard based on the occupant's feeling. [Structure] Based on a signal from a vibration state quantity detection sensor G associated with traveling, an evaluation value calculating means J for calculating at least two kinds of state evaluation values Ji and a content ratio of evaluation values which are occupant's sensory evaluation criteria are set. The state determination value H is calculated from the content ratio setting means N and the comprehensive evaluation value which changes momentarily based on the state evaluation value Ji and the content value ratio, and a predetermined threshold value H _opt.
And a gain setting means E for adjusting the gain of suspension control when the value is out of the range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension control gain adjusting device for adjusting a control gain of a device for controlling a suspension of a vehicle such as an automobile.

[0002]

2. Description of the Related Art An automobile encounters all running conditions from a flat road surface to a pavement repair road, to an irregular portion such as a seam on the road surface, and it is necessary to appropriately suppress vibrations according to the running condition.

In a conventional suspension control device for an automobile, it has been attempted to judge a change in a road surface, perform suspension control to positively change characteristics, and always give optimum control to improve ride comfort. It was For example, JP-A-6
In the device disclosed in Japanese Unexamined Patent Publication No. 0-261716, the sprung unsprung relative displacement X of an automobile and its rate of change dX are used as state quantities, the state evaluation value dX / X is determined from these values, and the range of possible values is set. Then, the state is determined by paying attention to the vibration component, for example, the state of the rugged component and the fluffy component is determined using a threshold value, and the determination results of both components are integrated to control the suspension.

[0004]

However, it has been found that in the above method, the control effect does not match the occupant's feeling of riding comfort and further fine adjustment is necessary. That is,
The surface condition of the road surface may be predominantly rugged components or fluffy undulations. In the conventional state determination, complicated vibration transmission systems (floor, seat, seat cushion) are used. As time passes, the vibration transmitted to the occupant changes, which causes a problem that sufficient ride comfort cannot be obtained. Generally, it is necessary to evaluate the riding comfort feeling in the running state by the main vibration evaluation amount transmitted by the occupant.Therefore, the evaluation amount according to the human vibration feeling must be introduced to accurately control the suspension characteristics of the vehicle. I have to.

Therefore, the present invention has been made in order to solve the above-mentioned problems of the prior art, and accurately evaluates the direct vibration related to the sensation of the occupant, and further, the evaluation standard based on the sensation of the occupant. It is an object of the present invention to provide a control gain adjusting device for a suspension that remarkably improves the riding comfort by optimally controlling the characteristics of the suspension.

[0006]

In order to achieve the above object, a control gain adjusting device for a suspension according to the present invention comprises:
As shown in FIG. 1, a plurality of vibration state amount detecting means for detecting a vibration state around the occupant when a seat is seated, and a plurality of sensory features that the occupant feels while the vehicle is traveling according to a predetermined arithmetic expression from the plurality of vibration state amounts. A plurality of evaluation value calculation means for calculating an evaluation value corresponding to, a plurality of evaluation values are weighted, a total evaluation value calculation means for calculating a total evaluation value of the plurality of evaluation values, and the total evaluation value Gain setting means for setting the gain of the suspension in comparison with the reference level.

[0007]

First, the principle of the present invention will be described. The correlation between the sensory evaluation value felt by the occupant while the vehicle was running and the plurality of vibration state quantities around the occupant when the seat was seated was calculated and subjected to multiple correlation analysis. As a result of this multiple correlation analysis, it was found that there are vibration state quantities that greatly contribute to the sensory evaluation value among the plurality of vibration state quantities, and these were selected. Then, these selected vibrational state quantities may correspond to major sensory components (eg, rugged component due to high frequency, fluffy component due to low frequency) of the actual sensory evaluation value by a predetermined multiple regression analysis. all right. Then, it was possible to construct a quantification formula for predicting a sensory component corresponding to the sensory component using the selected vibration state quantity. 2 important evaluation components
FIG. 2 shows the relationship between the state evaluation value obtained based on the state quantity in the case of types and the actual evaluation value.

Next, a plurality of state evaluation values J _i (i = A, B--) corresponding to the above important sensory components were derived. These state evaluation values J _i are shown in FIG. 3 for two cases of i = A and B. In the distribution of FIG. 3, the closer to the origin, the better the riding comfort.

Furthermore, the weighting of each sensory evaluation value J _i in the overall evaluation of the ride comfort of the occupant, that is, the evaluation value content ratio was calculated based on the sensory evaluation result. Based on this evaluation value content ratio, the overall evaluation level of the plurality of sensory evaluation values J _i was clarified.

As a result of the above examination, by introducing the content ratio of the sensory evaluation of the occupant into the sensory evaluation value J _i in accordance with the occupant's vibration sensation, an evaluation standard that matches the occupant's sensory evaluation tendency is provided. You can

[0011]

According to the present invention, the sensory evaluation value is obtained from the vibration state quantity detection signal, and the sensory evaluation value is weighted according to the content ratio to the overall evaluation to obtain the comprehensive evaluation value. Depending on the judgment, it is possible to adjust the control gain of the suspension and give the control characteristics that match the sensory evaluation of the occupant.

By adjusting the control gain of the suspension according to the present invention, it is possible to realize a vibration riding comfort that fits the vibration sensation of the occupant.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings. In the present embodiment, as shown in FIG. 4, a state quantity sensor G, which is a vibration state detecting means for detecting vibrations related to the sensation of an occupant, and sensor outputs X _1, X _2, X ₃ and Y _1, Y.
_2, an operation circuit than Y ₃ calculates the signal spectrum for each predetermined time, and spectrum integral value calculating circuit in a predetermined band width of the spectrum, comprising a band-by-band integral value of the spectrum from the logarithmic converter circuit for logarithmically converting Signal adjusting means S
A plurality of evaluation value calculating means J for obtaining a plurality of state evaluation values from the output signal from the signal adjusting means S, a content ratio setting means N for weighting the plurality of state evaluation values, and an evaluation value calculating means J. Comprehensive evaluation value computing means I for computing a comprehensive state evaluation value from both signals of the content ratio setting means N,
It comprises a gain setting means E for comparing the comprehensive evaluation value with a reference level and setting the gain of the suspension, and a control gain adjustment signal generator F.

As shown in FIG. 5, the state quantity sensor G of the present embodiment detects the vibration state quantity around the occupant.
Specifically, it consists of a vibration accelerometer embedded in the seat, a vibration accelerometer and a vibration velocity meter installed on the floor.

The signal adjusting means S calculates a signal spectrum from each state quantity sensor G at a predetermined time interval, obtains a spectrum integral value of the spectrum in a predetermined bandwidth, and further logarithmically transforms the integrated value. Is output. Then, the evaluation value calculation means J, out of the values obtained by logarithmically converting the integrated value,
A predetermined regression coefficient ai for the signal component in the frequency band 3 to 8 Hz
The first state evaluation value J _A represented by the multiple regression equation obtained by multiplying each item is calculated.

[0016]

## EQU1 ## J _A = a ₁ X _X1 + a ₂ X _X2 + a ₃ X _X3 Similarly, the second state evaluation value J _B is calculated as follows. At this time, a signal component in the frequency band 0.2 to 3 Hz is extracted.

[0017]

[Formula 2] J _B = a ₁ Y _X1 + a ₂ Y _X2 + a ₃ Y _X3 Next, the content ratio setting means N first weights the first state evaluation value J _A and the second state evaluation value J _B. Therefore, J _A : J _{B is set} to 6: 3, that is, the ratio is 2: 1. It should be noted that this ratio is an average value that is preset and can be corrected externally by the content ratio change switch.

According to the above example, the total evaluation value H calculated by the total evaluation value calculation means I is as follows.

[0019]

[Equation 3] However, n is a content ratio.

This equation shows the treatment of the state evaluation amount for each calculation cycle, and the treatment in this example is as shown in FIG. When the predetermined reference level in FIG. 6 is H _OPT , the gain setting means E gives the suspension change target value by the deviation amount between H _OPT and H. The gain setting means based on the deviation amount operates to switch the control gain setting so as to change the sensory evaluation values J _A and J _B in the vicinity of the origin in the figure. The output from the gain setting means E is output to the control gain adjustment signal generator F.

The control gain adjustment signal generator F operates in the gain adjustment stage of the control suspension to increase the displacement term coefficient gain in the active suspension, increase the equivalent rigidity in suspension control, and speed up the damping of vibration. Also, the speed term coefficient gain is reduced, and the equivalent damping coefficient in the suspension system control is also reduced, which acts to moderate the vibration convergence.

Next, a specific suspension structure in this embodiment will be described with reference to FIG. Note that FIG. 7 typically shows one front wheel and one rear wheel, that is, a suffix a,
Only c is shown.

The gas-liquid suspension is a front and rear wheel suspension, and includes a hydraulic pressure generator 44, an accumulator 45, four liquid quantity control valves 46a, 46b, 46c,
46d, four valve control devices 47a, 47b, 47c, 47d that control the liquid amounts of the four liquid amount control valves, and a liquid reservoir 4 that returns unnecessary oil and communicates with the suction side of the hydraulic pressure generation device 44.
8 and four actuators 50a, 50b, 50c, which communicate with the flow rate control valves 46a, 46b, 46c, 46d through pipes 49a, 49b, 49c, 49d, respectively.
50d and four gas springs 51a, 51b, which communicate with the pipe through the throttles 42a, 42b, 42c, 42d.
51c and 51d.

The hydraulic pressure generator 44 is a vane pump driven by an engine via a pulley, and accumulates hydraulic oil of a predetermined pressure in the accumulator 45 in advance. The vane pump is driven according to the rotation of the engine. This is because it is necessary to generate a larger force when turning or braking at high speed.

The accumulator 45 is composed of a metal container having a predetermined volume, and the inside of the container is divided into two by a rubber diaphragm. One chamber is filled with a gas such as nitrogen having a predetermined pressure, and the other chamber is filled with gas. It communicates with the discharge port of the pump through a pipe DP. This accumulator 45 compensates for the inoperability of the control device when the pump capacity is insufficient for the demand of the control device. Also,
By providing the accumulator 45, it is possible to reduce the capacity and size of the pump.

Flow control valves 46a, 46b, 46c, 46
Reference character d denotes a spool valve that moves axially in a cylinder provided with inflow and discharge ports and has a spool having a portion with a different outer diameter, and the positional relationship between the large diameter portion of the spool and the discharge port. By this, the opening area of the diaphragm is changed to control the discharge flow rate.

Valve control devices 47a, 47b, 47c, 47
Reference numeral d indicates that the nozzle flapper moves in response to the current of the output signal from the signal processing circuit to generate a differential pressure, and the differential pressure acts on both ends of the spool to move the spool. The spool is mechanically connected to the nozzle flapper, and when the spool moves, the spool moves the nozzle flapper in a direction that does not generate a differential pressure and fixes the valve opening. The actuators 50a and 50b are inserted between the lower arm LA of the wishbone type suspension of the front wheels and the vehicle body B, and stop the pistons Pa and Pb of the lower arms to the cylinders Ca and Cb.
Is locked to the vehicle body. Actuator 50c,
50b is disposed between the rear wheel RA and the vehicle body B, and has its pistons Pc and Pd locked to the arm RA and the cylinders Cc and Cd to the vehicle body B. Actuators 50a, 50b,
The cylinders Ca, Cb, Cc, Cd of 50c and 50d are connected to the pipe 49.
a, 49b, 49c, 49d through the flow control valve 4
The discharge ports 6a, 46b, 46c and 46d are connected to each other. The actuators used for the front and rear wheels are larger for the front wheels. This is to support the car body between the fulcrum of the lower arm LA and the wheels (arm ratio).

Gas springs 51a, 51b, 51c, 51d
Is composed of a metal container having a predetermined volume, the inside of the container is divided into two parts by a rubber diaphragm, one chamber is filled with a gas such as nitrogen having a predetermined pressure, and the other chamber is provided with throttles 42a, 42b. , 42c, 42d through the pipe 49
It communicates with a, 49b, 49c and 49d.

Therefore, the equivalent rigidity and damping performance of the suspension are adjusted by the output from the gain setting means,
Optimal riding comfort is ensured by controlling the four wheels.
FIG. 8 shows an example of the vibration acceleration waveform at the center of the sprung at the plot points on the state determination map of FIG. It can be seen that the waveform corresponding to each signal decreases rapidly by performing this vibration control.

In the apparatus of the present embodiment having the above-described structure, the vehicle is better when the damping force characteristic of the gas-liquid fluid spring is smaller by taking advantage of the soft spring characteristic of the gas-liquid fluid spring when the vehicle is traveling on a flat and good road. The ride comfort is good, and when passing through the irregular road surface, the degree of disturbance is recognized and the damping force characteristic of the gas-liquid fluid spring is set to a large state.
This has an advantage that the ride comfort can be optimized especially when the traveling state changes suddenly due to a sudden lane change or the like.

In this embodiment, the state quantity sensor G corresponds to the vibration state quantity detecting means, the signal adjusting means S and the evaluation value calculating means J correspond to the evaluation value calculating means, and the content rate setting means N.
The total evaluation value calculation means I corresponds to the total evaluation value calculation means, and the gain setting means E corresponds to the gain setting means.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration concept of the present invention.

FIG. 2 is a diagram showing a relationship between a state evaluation value obtained based on state quantities when there are two types of important evaluation components and an actual evaluation value.

FIG. 3 is a characteristic diagram showing a distribution of state evaluation values J _A and state evaluation values J _B.

FIG. 4 is a block diagram showing a schematic configuration of an example.

FIG. 5 is an explanatory diagram showing a mounting state of a vibration state quantity sensor.

FIG. 6 is a state determination map regarding the overall evaluation value H.

FIG. 7 is a configuration diagram showing a specific suspension structure in the example.

8 is a time chart showing an example of a vibration acceleration waveform at a sprung center at a plot point on the state determination map in FIG.

[Explanation of symbols]

 G state quantity sensor S signal adjusting means J evaluation value calculating means N content rate setting means I total evaluation value calculating means E gain setting means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Rikuo Ishiguro, Aichi-gun Nagakute-cho, Aichi-gun, Nagaminato 41-1 Yokomichi Toyota Central Research Institute Co., Ltd. Yokodomo 41-1 Toyota Central Research Institute Co., Ltd. (72) Inventor Masayoshi Takeda, 1-1, Showa-cho, Kariya City, Aichi Prefecture Nihon Denso Co., Ltd. (72) Inventor, Takayuki Nagai 1-1, Showa-cho, Kariya City, Aichi Prefecture Inside Nippon Denso Co., Ltd. (72) Inventor Hiroshi Ishikawa 1-1, Showa-cho, Kariya City, Aichi Prefecture Inside Nihon Denso Co., Ltd.

Claims (1)

[Claims] 1. A plurality of vibration state quantity detection means for detecting a vibration state around an occupant when a seat is seated, and a plurality of sensations that an occupant feels when a vehicle is traveling according to a predetermined arithmetic expression from the plurality of vibration state quantities. A plurality of evaluation value calculation means for calculating corresponding evaluation values, weighting the plurality of evaluation values, and a total evaluation value calculation means for calculating a total evaluation value of the plurality of evaluation values; A control gain adjusting device for a suspension, comprising: a gain setting means for setting a gain of the suspension in comparison with a level.