JPS61191405A - Method of controlling hard and soft characteristics of suspension for vehicle and its device - Google Patents

Abstract

PURPOSE:To control the hard and soft characteristics of the suspension of a vehicle and improve comfortableness to drive in the vehicle by receiving the radio waves containing the curvature of a curved road that are issued in front of the curved road and calculating the hard and soft characteristics value of the suspension when the vehicle passes through the curved road based on the said detected curvature and car speed. CONSTITUTION:When a vehicle is running, a CPU35 reads data with regard to the curving direction, curvature, and length of a curved road 50 from the radio waves 47 coming from a transmitting device 46 provided at the road side that is separated to this side from the admission point A of the curved road 50 only for the distance l1 while a receiving device 48 is receiving the radio waves. Then, the CPU determines the curving direction d, curvature R, and length L of the curved road 50 according to the program stored on a ROM36 and then integrates the running distance to be obtained based on the output of a car speed sensor 14. In addition, the CPU calculates the proper hard and soft characteristics value of the suspension of a vehicle from the said curvature R and car speed when the vehicle passes through the curved road and controls each of actuators 9 to 12 according to the calculation result and then controls the hard and soft characteristics of the suspension.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a suspension for a vehicle such as an automobile, and more particularly, it relates to a suspension for a vehicle such as an automobile, and more specifically, it relates to a suspension for a vehicle such as an automobile. The present invention relates to a method and apparatus for controlling the hardness and softness characteristics of a suspension.

Conventional technology When a vehicle such as an automobile turns, such as when driving on a curved road, centrifugal force acts on the vehicle body, causing the vehicle body to roll toward the outer wheels of the turn, reducing the steering stability of the vehicle. . For this reason, suspensions of vehicles such as automobiles have conventionally generally incorporated a stabilizer consisting of a set of torsion bars to improve the roll rigidity of the vehicle. In addition, with recent advances in electronic control technology, it is now possible to detect vehicle speed and wheel steering angle, and when these are above predetermined values, increase the damping force of the suspension, thereby reducing roll when the vehicle turns. This has already been done on some vehicles.

Problems to be Solved by the Invention In a vehicle equipped with a stabilizer, it is possible to reduce the roll of the vehicle body when the vehicle turns by increasing the spring constant of the stabilizer. Ride comfort deteriorates, and therefore, by increasing the spring constant of the stabilizer, it is not possible to sufficiently improve the steering stability when the vehicle turns while ensuring good ride comfort of the vehicle. In addition, in vehicles where the damping force of the shock absorber increases or decreases depending on the vehicle speed and the steering angle of the wheels, the damping force of the shock absorber will not be increased unless the wheels are steered by a predetermined amount or more, and if the steering angle exceeds a predetermined amount. Since there is a time lag from when it is detected that the damping force of the shock absorber is increased until the damping force of the shock absorber is increased, it is not possible to effectively and appropriately control the roll of the vehicle body, especially when the vehicle turns at medium and high speeds.

Furthermore, Japanese Patent Application Laid-Open No. 54-55923 discloses a control method and device in which information from a transmitting device installed on the roadside is used as an information source for controlling the running state of a vehicle.
This control method and device determines whether the vehicle speed when the vehicle is traveling on a curved road is within the safe speed range for the curved road by comparing it with information from a roadside transmitter. This is to ensure safety.
This control method and device cannot suppress the roll of the vehicle body when the vehicle travels on a curved road.

In view of the above-mentioned problems when conventional vehicles such as automobiles turn, the present invention provides a novel vehicle that can effectively and appropriately suppress body roll, especially when the vehicle travels on a curved road. The object of the present invention is to provide a method and apparatus for controlling the hardness and softness characteristics of a suspension for use in cars.

Means for Solving the Problems (1) According to the present invention, a method for controlling the hardness and softness characteristics of a suspension when a vehicle equipped with a suspension whose hardness and softness characteristics can be changed passes through a curved road. The curvature of the curved road is detected by receiving a spatial propagation wave that is radiated in front of the curved road and includes information on the curvature of the curved road when viewed in the direction of travel of the vehicle, and the curvature of the curved road is detected based on the curvature and the vehicle speed. a method for calculating appropriate hardness and softness characteristic values of the suspension when the vehicle passes through the curved road, and controlling the hardness and softness characteristics of the suspension based on the calculation results;
and a device for controlling the hardness and softness characteristics of the suspension when a vehicle equipped with a suspension that can change hardness and softness characteristics passes through a curved road, and the device controls the hardness and softness characteristics of the suspension when the vehicle passes through a curved road. a receiving device that receives a spatially propagating wave including information on curvature; a vehicle speed sensor that detects vehicle speed; an actuator that changes the stiffness and softness characteristics of the suspension; and a signal indicating the curvature from the receiving device and a signal from the vehicle speed sensor. This is achieved by a device having an arithmetic control device that calculates an appropriate stiffness characteristic value of the suspension when the vehicle passes through the curved road based on a vehicle speed signal, and controls the actuator based on the calculation result.

Effects and Effects of the Invention According to the control method and device of the present invention, the curvature of a curved road and the vehicle speed are determined before the curved road when viewed in the direction of travel of the vehicle, and the curvature of the curved road and the vehicle speed are determined based on the curvature of the curved road and the vehicle speed. Before entering the road, the appropriate hardness and softness characteristics of the suspension when the vehicle passes a curved road are calculated, and the hardness and softness characteristics of the suspension are controlled based on the appropriate hardness and softness characteristics values, so that the vehicle can easily pass through a curved road. It is possible to effectively and appropriately suppress the O-roll of the vehicle body when passing the vehicle.

According to one detailed feature of the control method of the present invention, by receiving a spatially propagating wave that is radiated in front of a curved road and includes information on the curvature of the curved road and the length of the curved road, as viewed in the traveling direction of the vehicle. The curvature and length of the curved road are detected, the appropriate hardness and softness characteristic values of the suspension when the vehicle passes through the curved road are calculated from the curvature and vehicle speed, and the hardness and softness characteristics of the suspension are calculated based on the calculation results. and determines whether the vehicle has substantially escaped from the curved road based on the length of the curved road and the vehicle speed, and when it is determined that the vehicle has substantially escaped from the curved road, the control is performed. It will be canceled.

Correspondingly, according to one detailed feature of the control device of the present invention, a spatially propagating wave is radiated in front of a curved road when viewed in the direction of travel of the vehicle and includes information on the curvature of the curved road and the length of the curved road. a receiving device that receives the information, a vehicle speed sensor that detects the vehicle speed, a seven-cut unit that changes the stiffness and softness characteristics of the suspension, and a vehicle that moves along the curved road based on a signal indicating the curvature from the receiving device and a vehicle speed signal from the vehicle speed sensor. Calculate appropriate hardness and softness characteristic values of the suspension when passing through the
and an arithmetic and control device that controls whether the vehicle has substantially escaped from the curved road based on a signal indicating the length of the curved road from the receiving device and a vehicle speed signal from the vehicle speed sensor. is determined, and when it is determined that the vehicle has substantially escaped from the curved road, the υ1111 is canceled.

According to another detailed feature of the control method of the present invention, the curved road is controlled by receiving a spatially propagating wave that is radiated in front of the curved road and includes information on the curvature of the curved road as viewed in the traveling direction of the vehicle. The curvature of the road is detected, the appropriate stiffness and softness characteristic values of the suspension when the vehicle passes through the curved road are calculated from the curvature and the vehicle speed, and the stiffness and softness characteristics of the suspension are controlled based on the calculation results, and the steering angle is adjusted. The control is canceled when the sensor detects that the steering angle of the wheels has become substantially zero.

Correspondingly, according to another detailed feature of the control device of the present invention, it receives a spatially propagating wave that is radiated in front of a curved road and includes information on the curvature of the curved road when viewed in the traveling direction of the vehicle. a receiving device for detecting the curvature, a vehicle speed sensor for detecting the vehicle speed, a steering angle sensor for detecting the steering angle of the wheels, an actuator for changing the stiffness and softness characteristics of the suspension, and a signal indicating the curvature from the receiving device and from the vehicle speed sensor. an arithmetic and control device that calculates an appropriate hardness and softness characteristic value of the suspension when the vehicle passes through the curved road based on a vehicle speed signal, and controls the actuator based on the calculation result; Based on the signal indicating the steering angle from the steering angle sensor, it is determined whether the vehicle has returned to a substantially straight-ahead state, and when it is determined that the vehicle has substantially returned to a straight-ahead state, the above-mentioned till Ill is determined. configured to release.

In this specification, "hardness and softness characteristics of suspension" means
It refers to the difficulty of relative vertical displacement between the vehicle body and the wheels, and specifically refers to the damping force of a shock absorber and/or the spring constant of a suspension spring. [Space propagation wave J means a wave that propagates in space and can transmit predetermined information, and may be, for example, a radio wave, a sound wave, light, etc.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be explained in detail below by way of example embodiments with reference to the accompanying figures.

Embodiment FIG. 1 is a perspective view showing the arrangement of various components of an embodiment of a vehicle suspension hard/soft characteristic control device according to the present invention applied to a vehicle equipped with an automatic transmission. Enlarged partial vertical sectional view showing the main parts of one front suspension shown in the figure, No. 3
The figure is a block diagram of the embodiment shown in Figure 1, Figure 4 is a block diagram of a transmitter installed on the roadside in front of a curved road when viewed from the direction of the vehicle's progress, and Figure 5 is a block diagram of the transmitter installed on the roadside in front of a curved road. FIG. 2 is an illustrative plan view showing a situation when a car travels on a curved road.

In these figures, especially in FIG. 1, 1 to 4 indicate shock absorbers provided corresponding to front wheels 5 and 6 and rear wheels 7 and 8, respectively, and 1a and 2a respectively indicate front wheels. Air springs provided corresponding to 5 and 6 are shown. Actuators 9 to 12 are provided at the upper end of each shock absorber, and although not shown in the figure, each actuator is provided on the piston of the corresponding shock absorber to communicate and connect the cylinder upper chamber and the cylinder lower chamber. By switching the effective passage cross-sectional area of the orifice in multiple stages, the damping force of each shock absorber can be switched and set in multiple stages including high level, medium level, and low level.

If you need a detailed explanation of the structure and operation of the variable damping force angle shock absorber, please refer to Automotive Technology Vol. 1.38 published by the Society of Automotive Engineers of Japan. No.

10.1984. Please refer to "About variable damping force type shock absorber" on pages 1168 to 1171.

As shown in detail in FIG. 2, the shock absorber 1 is connected to the vehicle body 103 at the upper end of its piston rod 101 by an upper support 102, and the actuator 9 is connected to a cooling ring 103 of the upper support 102.
is housed within.

The air spring 1a includes a disk member 105 fixed to a piston rod 101, a piston 107 fixed to a cylinder 106 of the shock absorber 1, and a disk member 105.
A rolling diaphragm 108 is provided between the piston 107 and the piston 107 and has a substantially O-shaped cross section, and a main air chamber 109 is defined by these rolling diaphragms 108 . The air spring 1a is caused by the piston 107 being driven upward in the figure relative to the disk member 105 as the wheels (not shown) bounce, and the air in the main air chamber 109 being compressed. It is designed to generate spring force.

A conduit 110 is fixed to the disc member 105 , and the main air chamber 109 is connected in communication with an auxiliary air chamber 112 having a constant volume of an auxiliary tank 111 through the conduit.
A normally closed electromagnetic on-off valve 41 that selectively establishes communication between the main air chamber 109 and the auxiliary air chamber 112 is provided in the middle. When the solenoid (not shown in the figure) is not energized, the electromagnetic on-off valve 41 maintains a closed state and cuts off communication between the main air chamber 109 and the auxiliary air chamber 112, thereby closing the air spring 1a. The spring constant of the air spring 1a is maintained at a high level, and when the solenoid is energized, the valve is opened to connect the main air chamber 109 and the auxiliary air chamber 112, thereby switching the spring constant of the air spring 1a to a low level. It functions as an actuator.

Although not shown in detail in the figure, the shock absorber 2 is also connected to the vehicle body like the shock absorber 1, and the air spring 2a is configured similarly to the air spring 1a, and has a normally closed electromagnetic on-off valve. 42 (see Figure 3)
By controlling the energization to the spring constant, the spring constant is switched between a high level and a low level. If it is necessary to control the spring constant in two or more stages, two or more auxiliary tanks may be installed, and in that case, each auxiliary tank communicates with the main air chamber through a separate dedicated pipe with an electromagnetic on-off valve in the middle. Alternatively, a plurality of auxiliary tanks having mutually different volumes may be configured to be selectively connected to the main air chamber via an electromagnetic switching valve including a closed position.

The instrument panel 13 in the vehicle interior is provided with a vehicle speed sensor 14 that is built into a vehicle speed meter provided on the instrument panel and detects the traveling speed of the automobile and outputs a vehicle speed signal indicating the traveling speed. A steering angle sensor 17 is provided at the tip of the steering column 15 for detecting the turning angle of the steering wheel 16, and therefore the steering angles of the front wheels 5 and 6, and outputting a steering angle signal indicating the steering angle. The throttle body of the internal combustion engine 18 is provided with a throttle position sensor 19 that detects the opening of a throttle valve provided in the throttle body and outputs a throttle opening signal indicating the opening. A brake pedal (not shown in the figure) installed in the vehicle interior closes when the brake pedal is depressed, and outputs a braking signal indicating that the vehicle is being braked. A stop lamp switch (SW) 20 is provided as a braking sensor.

A shift lever position signal is output to a position close to the shift lever 22 of the automatic transmission 21, which is closed when the shift lever is in the neutral range or parking range, and indicates that the shift lever is in the neutral range or parking range. A neutral start switch (SW) 23 is provided as a shift position sensor. A shock absorber 1 is located near the instrument panel 13.
A mode select switch unit 24 is provided for selecting the damping force control mode of 4 to 4, and this unit has a mode select switch (SW) 25 and a mode select switch (SW) as shown in FIG. )26
It is becoming more and more. The instrument panel 13 is provided with an indicator 27 that displays the damping force control mode selected by operating the switch unit 24 and the magnitude of the damping force of the shock absorber, and an indicator 27a that displays the magnitude of the spring constant of the air spring. There is. These components are communicatively connected to an electronic control unit 28 by conductors not shown in FIG.

As shown in FIG. 3, the electronic control device 28 drives a microcomputer 29, drive circuits 30 to 34 for driving actuators 9 to 12 and indicators 27, electromagnetic on-off valves 41 and 42, and indicators 27a. It consists of drive circuits 43 to 45 for the purpose of The microcomputer 29 may have a general configuration as shown in FIG.
tJ) 35, a read-only memory (ROM) 36,
It has a random access memory (RAM>37), an input boat device 38 and an output boat device 39, which are interconnected by a bidirectional common bus 40.

The input boat device 38 receives mode select signals from the mode select switches 25 and 26, a vehicle speed signal from the vehicle speed sensor 14, a steering angle signal from the steering angle sensor 17, and a throttle opening signal from the throttle position sensor 19. , a braking signal from the stop lamp switch 20 and a shift lever position signal from the neutral start switch 23 are input, and these signals are appropriately converted and output to the CPU and RAM 37 according to instructions from the CPU 35. . According to the program stored in the 80M36, the CPLI 35 determines the control mode of the damping force of the shock absorber according to the combination of mode select signals (on-off signals) according to the correspondence shown in Table 1 below.

That is, the CPIJ 35 determines that the control mode is the manual mode when the mode select signal from the switch 25 is an off signal, and in particular determines that the control mode is the manual mode when the mode select signal from the switch 26 is an off signal. (NORMΔ) is determined to be the fixed manual mode, and if the mode select signal from the switch 26 is an on signal, the control mode is set to sport (SPO).
(R)) It is determined that the mode is fixed manual mode.

When it is determined that the control mode is manual mode, the CPU 35 outputs control signals to the boat device 39 according to the program stored in the ROM 36, regardless of signals from various sensors and switches. Then, the drive signals are outputted to the drive circuits 30 to 33, and each drive circuit outputs a drive signal to the corresponding actuator 9 to 12. When the control mode is the normal fixed manual mode, the damping of each shock absorber is controlled. When the force is fixedly set at that low level and the control mode is a manual mode with sports fixed, the damping force of each shock absorber is fixedly set at that middle level.

Further, the CPU 35 determines that the control mode is the auto mode when the mode select signal from the switch 25 is an on signal, and in particular, when the mode select signal from the switch 26 is an off signal, the control mode is determined to be the auto mode. It is determined that the NORM△-based auto mode is selected, and if the mode select signal from the switch 26 is an on signal, the control mode is set to sport (S).
It is determined that the mode is PORT>based auto mode. Then, according to the program and map stored in the ROM 36, the CPU 35 adjusts the damping force of the shock absorber to a value suitable for ensuring the ride comfort of the vehicle and reducing changes in the vehicle's attitude, based on the output signals of each sensor and switch. Port device 3 that outputs control signals to control
9 to drive circuits 30 to 33, and the drive circuit outputs a drive signal to each corresponding actuator. In this case, if the control mode is normal-based auto mode, the damping force of the shock absorber is adjusted to low, medium, and high levels based on the signals from each sensor and switch, that is, depending on the vehicle driving condition. When the control mode is a sports-based auto mode, the damping force of the shock absorber is automatically switched between a medium level and a high level depending on the driving condition of the vehicle. In each of the above-mentioned control modes, the CPU 35 also outputs a control signal to the drive circuit 34 via the output port device 39, so that the indicator 27 displays each damping force control mode.

In addition, in the above-mentioned damping force 11.1J111, the damping force of the shock absorber is appropriately switched to a low level, medium level, or high level based on signals from various sensors such as the switch unit 24 and the vehicle speed sensor 14. By setting, the roll of the vehicle body when the vehicle turns, the auto body and nose dive when the vehicle accelerates and decelerates,
Shift auto that occurs when a shift operation is performed while the vehicle is stopped is suppressed, and the steering stability of the vehicle when traveling at high speeds is improved. Since such control does not constitute the gist of the present invention, a detailed explanation thereof will be omitted in this specification, but if necessary, the details of such control can be found in the application filed by the same applicant as the present applicant. Such patent application 1982-.
See No. 172146.

Further, in this specification, control of the shock absorber based only on signals from various sensors such as the above-mentioned switch unit 24 and vehicle speed sensor 14 will be referred to as normal damping force control.

The input boat device 38 of the microcomputer 29 includes:
Radio waves 47 emitted from the transmitter 46 shown in FIG.
is received by the receiving device 48, the radio wave 47
A receiving device 48 inputs signals regarding various types of information included in the information. As shown in FIG.
It is provided on the roadside at a distance of 11 from the approach point Δ of 0. The transmitting device 46 includes an oscillator 51, a buffer 52, and a modulator B53, and the carrier wave of the original oscillation frequency generated by the oscillator is inputted to the modulator 553 via the buffer 52. The transmitting device 46 also includes an encoder 54, a control circuit 55, and a multiplier 56, and the curvature direction d1 of the curved road 50 is the curvature R1 of the curved road. A code signal in a predetermined format indicating the length along the travel path to the escape point B of
3, the carrier wave is thereby modulated, and the thus modulated carrier wave is multiplied by a multiplier 56 to a predetermined frequency and is emitted from an antenna 57.

In particular, in the illustrated embodiment, the radio waves 47 are circularly polarized FM radio waves with unidirectionality, as indicated by hatching in FIG. The antenna 5 of the transmitting device 46 is tilted in a direction opposite to the direction of travel.
It is designed to be fired from 7 onwards. In FIG. 5, point C indicates the point at which the receiving device 48 of the automobile 49 becomes able to receive the radio waves 47, and a dot indicates the point at which the receiving device 48 becomes unable to receive the radio waves 47. Point E is a point on the traveling route of the car 49 and is located on the side of the transmitting device 46, and the distance 12 is the distance from point C to the receiving device @48. indicates the distance at which the radio wave 47 can be received, and 13 indicates the distance from the dot to point E. Distances II and 13 are preferably constant values that are unified between each transmitter, but distance II
and 13 are different for each transmitting device, these pieces of information are incorporated into the radio waves emitted from the transmitting device.

As shown in FIG. 3, the receiving GI device 48 includes an antenna 58, an amplifier 59, a mixer 60, an amplifier 61,
The high-frequency current of the radio wave received by the antenna 58 is amplified by the amplifier 59, frequency-converted by the mixer 60, amplified by the amplifier 61, and then amplified by the demodulator 62. The signal is demodulated into a digital signal indicating the curvature direction d of the curved road, the curvature R1, and the road length, and is then input to the input port device 38 of the microcomputer 29. The ROM 36 of the microcomputer 29 stores a map of the relationship between the curvature R of the curved road and the appropriate control level F of the damping force of the shock absorber, and the curvature R of the curved road and the appropriate gradient number of the air spring for each predetermined vehicle speed range. It stores a map of the relationship between the control level and the distance value.

Next, referring to the illustration in FIG. 5 and the flowcharts in FIGS. 6 and 7 showing the control flow of the embodiment shown in FIGS. 1 to 3, The operation of the embodiment and the control method of the present invention implemented by the apparatus of this embodiment will be described.

First, in the first step 1 of the flowchart shown in FIG.
2 is initialized, the damping force of each shock absorber 1 to 4 is set to a low level, and the air spring 1 is initialized.
The spring constants of a and 2a are set to a low level.

In the next step 2, the mode select switch 25
and 26, the vehicle speed detected by the vehicle speed sensor 14, the steering angle detected by the steering angle sensor 17, the throttle opening detected by the throttle position sensor 19, and the vehicle detected by the stop lamp switch. Normal damping force control is performed based on data on whether or not the brake is in a braking state and data on whether or not the neutral start switch 23 is closed.

In the next step 3, the radio waves 47 from the transmitter 46
It is determined whether or not the radio waves have been received, and if it is determined that the radio waves are not being received, step 2 is repeated, and if it is determined that the radio waves are being received, then step 2 is repeated. Proceed to the next step 4.

In step 4, data regarding the curve direction, curvature, and path length of the curved road 50 is read from the receiving device 48.

In the next step 5, the CPU 35 determines the curve direction d1, curvature R1, and road length of the curved road according to the program stored in the ROM 36, and the 8 values are stored in the RAM 3.
7 is stored.

In the next step 6, it is determined whether or not it is no longer possible to receive the radio waves 47, that is, whether the antenna 58 of the car 49 has reached a fixed point, and reception of radio waves is continued. If it is determined that the radio wave is present, step 6 is repeated, and if it is determined that radio waves cannot be received, the process proceeds to step 7.

In step 7, an instruction to start measuring the distance traveled by the automobile is issued, and as a result, the interrupt routine shown in FIG. 7 is repeatedly executed every .DELTA..degree.

In the flowchart shown in FIG. 7, when an instruction to start calculating the mileage is issued in step 7 described above, in the first step 21, the data is stored in the RAM 37 of the microcomputer 29. Data related to mileage will be cleared.

In the next step 22, data related to the vehicle speed is read from the vehicle speed sensor 14, and in the next step 23, the traveling distance ΔD of the car in a minute time Δ℃ is calculated by multiplying The calculation is performed and the calculation result is stored in RAM3.
7 is stored.

In the next step 24, by adding the travel distance ΔD for each minute time stored in the RAM 37, the cumulative value of the travel distance from the start of travel distance calculation to that point is calculated. Ru.

In the next step 25, it is determined whether or not an instruction to stop calculating the mileage has been issued, and if it is determined that the instruction has not been issued, then Steps 22 to 25 described above are repeated, and if it is determined that an instruction to stop calculating the mileage has been issued, the process is directly reset.

In step 8, which is performed after step 7 in the flowchart shown in FIG.
is read.

In the next step 9, R obtained in step 5 is
Based on the data on the curvature R of the curved road stored in the AM37 and the data on the vehicle speed V obtained in step 8, various settings suitable for suppressing the roll of the vehicle body when the automatic 1i49 passes the curved road 50 are determined. A control level F of the damping force of the shock absorber and a control level K of the spring constant of each air spring are calculated.

In the next step 1o, the actual damping force level Fa of each shock absorber set in step 2 is detected.

In the next step 12, by comparing the damping force control level F obtained in step 9 with the actual damping force level Fa obtained in step 10, the damping force is determined for each shock absorber. A force correction value Fc, that is, a value indicating how many steps the damping force control level should be increased or decreased from the actual damping force level is calculated, and the correction value is stored in the RAM 37.

In the next step 13, the accumulated distance calculated in step 24 of the flowchart shown in FIG. 7 is compared with the distance 11+la stored in the RAM 37, and 11+1. -Δl<Q≦ 11 + 1゜(Δ
1 is a constant value smaller than 1 and 13), it is determined whether the automobile 49 has reached the entry point of the curved road 50 or not. If it is determined that the vehicle has not reached the point A, the process proceeds to the next step 13, and if it is determined that the vehicle has reached the approach point A, the process proceeds to the next step 15. .

In step 13, the vehicle speed V is read from the vehicle speed sensor 14.

In the next step 14, it is determined whether the vehicle speed has changed by a predetermined amount of 67 or more by comparing the vehicle speed determined in step 8 and the vehicle speed determined in step 13. If it is determined that the vehicle speed has changed by a predetermined amount or more, the process returns to step 9, and if it is determined that the vehicle speed has changed by less than a predetermined amount, the process returns to step 1.
Return to 2.

In step 15, the damping force determined in step 11 is corrected by 1! A signal indicating F c is output from the output port device 39 to each drive circuit, thereby correcting the damping force of each shock absorber 1 to 4. Further, the signal indicating the control level of the spring constant obtained in step 9 is sent to the outer turning wheel via the output port device 39 based on the data on the curve direction d of the curved road obtained in step 5 and stored in the RAM 37. It is output to the drive circuit 43 or 44 corresponding to the air spring on the side, thereby increasing the spring constant of the air spring 1a or 2a on the outer turning wheel side.

In the next step 16, the length of the curved road obtained in step 5 and stored in the RAM 37 and the seventh
The cumulative value of the mileage calculated in step 24 of the flowchart shown in the figure and stored in the RAM 37,
Distance stored in ROM1. +1. From the data of
9 has reached the exit point B of the curved road. If it is determined that the vehicle has not reached the escape point, steps 15 and 16 are repeated, and if it is determined that the vehicle has reached the escape point, the next step 17 is performed. Proceed to.

In step 17, an instruction is issued to stop the travel distance calculation according to the flowchart shown in FIG. After step 17 is executed, the process returns to step 2, and steps 2 to 17 and steps 21 to 25 are repeated.

FIG. 8 shows a flowchart similar to FIG. 6 showing the control flow of another embodiment of the plate control device of the present invention. Note that steps in FIG. 8 that are substantially the same as those shown in FIG. 6 are given the same step numbers.

In this embodiment, steps 1 to 14 are the same as those in the above embodiment, except that in step 5, only the curvature direction d and curvature R of the curved road are determined and stored in the RAM 37 of the two microcomputers. It is executed in the same way as in the case of . If it is determined in step 12 that the automobile 49 has reached the entrance point of the curved road, the process proceeds to the next step 12a, and the distance traveled by the automobile is calculated according to the flowchart shown in FIG. An instruction is issued to stop the operation.

In the next step 15, the damping force of each shock absorber is corrected in the same manner as in the above embodiment, and the spring constant of the air spring is increased as necessary, and in the next step 16a, the damping force of each shock absorber is corrected. In step 16b, the steering angle θ detected by the steering angle sensor 17 is read.
In this case, whether or not the vehicle returned to a substantially straight-ahead state;
In other words, whether or not the steering angle θ is within a predetermined range including 0 (-
A determination is made as to whether or not θ weight≦θ≦θI (θ1 is a positive constant) is satisfied. If it is determined that the vehicle has not returned to a substantially straight-ahead state, step 1
5. Steps 16a1 and 16b are repeated, and if it is determined that the vehicle has returned to a substantially straight-ahead state, the process returns to step 2, and steps 2 to 16b are repeated.
and Steps 21-- of the flowchart shown in FIG.
25 is repeated.

Further, after a predetermined period of time after the vehicle reaches the entry point A of the curved road 50, the damping force of each shock absorber is controlled according to the control method and device of the present invention, and the spring constant υJI of each air spring is released. In an embodiment configured to perform the following steps, steps 16a and 16b in the flowchart shown in FIG. 8 may be performed in step 12 of FIG. This step is replaced with a step of determining whether or not a predetermined amount of time has elapsed since the determination that a predetermined amount of time has passed since the determination that the predetermined amount of time has passed. The process is repeated, and if a predetermined period of time or more has elapsed and it is determined that lζ is true, the process returns to step 2.

In each of the above-mentioned embodiments, the damping force of each shock absorber is controlled and the spring constant of each air spring is controlled. It may be configured such that only one of the spring constants of each air spring is controlled;
The spring constant of the air spring may be controlled not only on the outer turning wheel side but also on the inner turning wheel side. Furthermore, in the above-described embodiment, the spring constant of each air spring is controlled by increasing or decreasing the volume of their air chambers. The spring constant and vehicle height may be controlled by increasing the air pressure and reducing the air pressure in the air chamber of the air spring on the inner wheel side of the turn.

Further, in the embodiments described above, the air spring is incorporated only in the front suspension, but the air spring may be incorporated only in the rear suspension, or in both the front suspension and the V-suspension, or it may be incorporated in the suspension. The suspension spring may be any spring other than an air spring, as long as its spring constant can be increased or decreased by any suitable actuator. Also distance 11
may be O, in which case steps 12 to 14 of the flowchart of FIG. 6 are omitted, and steps 7, 12.12a, 1 of the flowchart of FIG.
3.14 is omitted.

Although the present invention has been described in detail with respect to specific embodiments above, the present invention is not limited to these embodiments, and various other embodiments are possible within the scope of the present invention. This will be obvious to those skilled in the art.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the arrangement of various components of an embodiment of a vehicle suspension hard/soft characteristic control device according to the present invention applied to a vehicle equipped with an automatic transmission, and FIG. An enlarged partial longitudinal sectional view showing the main parts of one front suspension shown in Figure 3.
The figure is a block diagram of the embodiment shown in Figure 1, Figure 4 is a block diagram of a transmitting device installed in front of a curved road when viewed from the direction of travel of the vehicle, and Figure 5 is a block diagram of the embodiment shown in Figure 1. FIG. 6 and FIG. 7 are flowcharts showing the control flow of the embodiment shown in FIGS. 1 to 3, and FIG. 7 is a flowchart similar to FIG. 6 showing the control flow of one embodiment of the hardness/softness characteristic control device for a suspension for use in vehicles; 1 to 4...Shock absorber, 1a, 2a...
Air spring, 5-8...Wheel, 9-12...Actuator, 13...Instrument panel, 1
4...Vehicle speed sensor, 15...Steering column,
16... Steering wheel, 17... Steering angle sensor. 18... Internal combustion engine, one... Throttle position sensor, 20... Stop lamp switch, 21...
・Automatic transmission, 22...Shift lever-123...Neutral start switch. 24...mode select switch unit, 25.
26...Mode select switch, 27.27a...
・Indicator, 28...Electronic control device, 2...
Microcomputer, 30-34... Drive circuit, 3
5... Central processing unit (CPU), 36... Read only memory (ROM>, 37... Random access memory (RAM), 38... Input board device, 39
... Output boat device, 40... Common bus, 41.
42...Electric! 1 on-off valve, 43-45... drive circuit,
46... Transmitting device, 47... Radio wave, 48... Receiving device, 49... Car, 50... Curved road, 51...
...Oscillator, 52...Buffer, 53...Modulator,
54... Encoder, 55... Control circuit, 56...
・Multiplier, 57.58...Antenna, 5...Amplifier, 60...Mixer, 61...Amplifier, 62...
demodulator, 101... piston rod, 102... upper support, 103... vehicle body, 104... casing, 105... disc member, 106... cylinder,
107... Piston, 108... Rolling diaphragm, 109... Main air chamber, 110... Conduit, 1
11...Auxiliary tank, 112...Auxiliary air chamber Patent applicant Toyota Motor Corporation! ll car corporation representative
Patent attorney Masa Akashi
Membrane bundle 1 Figure 2 Figure 4 Figure 5

Claims (2)

[Claims] (1) A method for controlling the hard and soft characteristics of the suspension when a vehicle equipped with a suspension whose hard and soft characteristics can be changed passes through a curved road, and the curve is radiated in front of the curved road when viewed from the direction of travel of the vehicle. The curvature of the curved road is detected by receiving a spatial propagation wave containing information on the curvature of the road, and an appropriate hardness/softness characteristic value of the suspension when the vehicle passes the curved road is determined from the curvature and vehicle speed. , a method of controlling the hardness and softness characteristics of the suspension based on the calculation result. (2) A device for controlling the hard and soft characteristics of the suspension when a vehicle equipped with a suspension whose hard and soft characteristics can be changed passes through a curved road, and the device is configured to control the hard and soft characteristics of the suspension when the vehicle passes through a curved road, and the device is configured to provide a device that is radiated in front of the curved road when viewed from the direction of travel of the vehicle. a receiving device that receives a spatially propagating wave containing information on road curvature; a vehicle speed sensor that detects vehicle speed; an actuator that changes the stiffness and softness characteristics of the suspension; a signal indicating the curvature from the receiving device; and the vehicle speed sensor. an arithmetic and control device that calculates an appropriate hardness and softness characteristic value of the suspension when the vehicle passes through the curved road based on a vehicle speed signal of the vehicle, and controls the actuator based on the calculation result.