JPH04113911A - Suspension controlling device - Google Patents

Abstract

PURPOSE:To control a vibration damping means of a vehicle in a mode to match the total running characteristics of the vehicle by changing the damping force of a sock absorber corresponding to the condition of a running characteristics control system of the vehicle. CONSTITUTION:A vehicle has a four wheel steering system 2 which can be changed between a normal mode and a sports mode, and a running characteristics control system 100 equipped with various systems 4-10. It also has a shock absorber 300 of which damping force characteristics can be changed, and a sock absorber controller 200 for changing the damping force characteristics. In this constitution, a means 400 for inputting a signal for indicating a condition into which the running characteristics control system 100 of the vehicle is changed to the controller 200 is added. The controller 200 also includes a memorizing means 202 to memorize changing procedures 1-4 for changing the damping force characteristics of the shock absorber 300 in a corresponding mode to the signal inputted from the inputting means 400.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vibration damping system for a vehicle,
In particular, the present invention relates to a suspension control device that can satisfactorily switch damping force characteristics in a vehicle equipped with a shock absorber whose damping force characteristics can be switched between heart and soft.

[Prior Art] Japanese Patent Laid-Open No. 6467407 discloses a device for switching the damping force characteristics of a vehicle equipped with a shock absorber whose damping force characteristics can be switched between heart and soft.

This device is equipped with means for detecting the damping force currently being produced in the shock absorber, and based on this detected value, the damping force characteristics are switched to obtain the optimum damping force.

Further, Japanese Patent Application Laid-Open No. 1-202512 also discloses a switching device, which also switches the damping force characteristics based on the damping force that is actually occurring.

[Problems to be Solved by the Invention] As described above, all conventional switching devices switch the damping force based only on the state of the vibration damping device.
It does not control based on the overall characteristics of the vehicle.

Modern vehicles are often equipped with a driving characteristic control system that can change the driving characteristics of the vehicle. For example, when changing the steering angle of the rear wheels in a four-wheel steering vehicle depending on the vehicle speed, there are two modes: normal mode, which makes handling easier by turning the steering a lot relative to the vehicle speed, and normal mode, which makes handling easier by turning the steering a little more than the vehicle speed. It is known that there is a system that allows you to select a sports motor (for example, Toyota Celica new car manual 19)
September 1989 issue).

Furthermore, in electronically controlled transmissions, a system is known in which a user can select a torque mode that changes gears so that a larger torque than usual is output (for example, Toyota Sergio New Model Manual, October 1989 issue).

In addition, a system that allows air suspension to switch between normal mode and sports mode has already been put into practical use (for example, Toyota Sergio new model car manual October 1989).
month issue). In addition, the driving characteristics of the transmission differ between when the vehicle is driven in the "D" range and when the vehicle is driven in the "L" range. Furthermore, since the driving characteristics differ when the Auto Tribe Nostem, which keeps the vehicle speed constant, is turned on and when it is turned off, this can also be considered a system that controls the driving characteristics of the vehicle.

The overall characteristics of the vehicle are determined based on the states of these driving characteristic control systems, and therefore it is preferable that the vibration damping device of the vehicle is also controlled to match these systems.

For example, even though sports mode is selected for the four-wheel steering system, if the damping force characteristics of the shock absorber are maintained soft, the overall driving characteristics of the vehicle may not necessarily be in harmony. It won't happen.

Therefore, the present invention attempts to make it possible to control the vibration damping device of a vehicle in a manner that matches the overall driving characteristics of the vehicle.

"Means for Solving the Problems" The above problems are solved by the vehicle whose schematic diagram is shown in FIG. ) system 4 that can switch between normal mode and torque-oriented mode, system 6 that can switch between air suspension normal and sport mode, system 8 that can select between D range and L range, or switch between auto drive on and off. A vehicle has a driving characteristic control system 100 such as a system 10, a shock absorber 300 capable of switching the damping force characteristic between a hard state and a soft state, and a shock absorber controller 200 that switches the damping force characteristic of the shock absorber 300. The problem can be solved by making the following improvements.

That is, in the suspension control device of the present invention, a signal indicating the state in which the vehicle driving characteristic control system 100 is switched (such as a signal indicating whether the normal mode or the sport mode is selected) is sent to the controller 200. Means 400 for inputting information is added. Further, the controller 200 has a switching procedure 1, 2, 3, 4 for switching the damping force characteristics of the shock absorber 300 in a manner corresponding to the signal input from the input means 400.
A storage means 202 for storing... is built-in.

Note that the 4WS, ECT, etc. mentioned here are just examples, and the vehicle driving characteristics control system 100 does not need to include all of these systems, and even if it has other driving characteristics control systems. good.

Also, switching procedure 1. 2. 3... may be based on different processing procedures, or may control switching of the damping force in substantially different ways by using different parameters in the same processing procedure. .

[Operation] According to the suspension control device having the same configuration as above, the damping force of the shock absorber 300 is switched depending on the state of the vehicle driving characteristic control system 100. For example, when the 4WS is switched to sports mode, the shock absorber is switched to
<300 can be switched, and the shock absorber (300 is switched in a manner consistent with the overall driving characteristics of the vehicle.The switching procedure corresponds 1:1 to the state of the specific driving characteristics control system. It may be selected according to a combination of several driving characteristic control systems.

In any case, compared to the prior art which switches the damping force solely based on the state of the vibration damping device, the present invention allows the damping force to be switched in a manner that provides more comprehensive machining. can.

[Example] Next, embodiments of the present invention will be specifically described.

FIG. 2 shows the system configuration of this embodiment. In the figure, 12 is a 4WS computer that controls the four-wheel steering system, 14 is an ECT computer that controls the electronically controlled transmission, and 16 is the air suspension computer. Air suspension computer, 18 is a position sensor that detects the selected position of the transmission, 2
0 (This shows the switch to turn the auto drive system off and on.

The controller 200 has a built-in multiplexer 204, and flag information indicating whether the 4WS steering system is in the sport mode or the normal mode can be input to the CPI '208 via the communication line 402. . Further, flag information indicating whether the suspension is in the transmission suspension, torque motor, or normal motor is transmitted via the communication line 404, and flag information indicating whether the air suspension is in the normal motor or the sports motor is transmitted via the communication line 406. Then, a D-L signal indicating whether the transmission is in the D range or L range is transmitted via the communication line 408, and a signal indicating whether the auto drive switch is on or off is transmitted via the communication line 410. Each of the CPUs 208 can be manually operated.

ROM202 is connected to CPO208, and RO
M202 includes a storage means 202a that stores a processing procedure for determining the combination state of the input mode (the mode in which the driving characteristic control system is selected), and a storage means 202a that stores a processing procedure for determining the combination state of the input mode (the mode in which the driving characteristic control system is selected), and one of the switching procedures based on the determined combination. A storage means 202b that stores processing procedures for selecting the , and a storage means 2 that stores selectable switching procedures 1 to 3, respectively.
G2c, 202d, 202e, storage means 202f for storing processing procedures for learning the switching reference value Vref used in each switching procedure, means 202g for storing parameters at that time, etc. are built-in. has been done.

A RAM 206 is also connected to the CPU 208 and is used when executing various processing procedures. Further, a drive circuit 210 is connected to the CPU 208.

The drive circuit 210 switches whether or not to apply a high voltage to the piezo element 302 based on a signal from the CPU 208.

This piezo element 302 is similar to that disclosed in Japanese Patent Application Laid-Open No. 64-67407 or Japanese Patent Application Laid-open No. 1-202512, and when a high voltage is applied, the orifice area increases and the shock absorber 302 Switch the damping force characteristics to soft. The damping force characteristics of the shock absorber 300 are in a hard state unless a high voltage is applied.

Now, the mode combination determination process 202a determines whether the damping force characteristic of the vehicle vibration damping device should be hard or intermediate, based on the combination of signals related to the modes of each driving characteristic control system that are inputted sequentially through the multiplexer 204. Determine whether the state is in a weak state or the state in which the software should be.

In this embodiment, the switching procedure 1 stores a procedure for maintaining the damping force characteristic of the shock absorber 300 as hard as possible, and the switching procedure 3 stores a procedure for maintaining it as soft as possible.

The switching procedure 2 stores a processing procedure for switching between software and hardware in an intermediate manner.

Therefore, the switching procedure selection processing storage means 202b stores switching procedure 1 when the combination determined in processing procedure 202a requires hard characteristics, switching procedure 2 at an intermediate stage, and switching procedure 2 when soft characteristics are required. A processing procedure for selecting procedure 3 is stored.

In the switching procedure 1, a process is stored in which the time rate of change of the damping force obtained by the shock absorber is compared with the first switching reference value Vrefl, and when the actually measured rate of change is larger than the switching reference value, a soft switch is performed. ing.

Almost the same process is stored in switching procedure 3, or the third switching reference value V ref3 used here is a smaller value than the first switching reference value Vrefl, and when switching procedure 3 is used, the switching procedure It is easier to switch to software than in case 1.

In switching procedure 2, the same switching reference value as the first switching reference value Vrefl is used, but the time to hold the software immediately after switching from hard to soft is set longer than in switching procedure J, and the switching procedure When switching procedure 2 is used, soft adjustment is easier than when switching procedure 1 is used.

Note that the switching procedures 1 to 3 may be used for the same processing procedure, and the parameters used therein may be different.

In this embodiment, an example is shown in which the damping force characteristics are divided into three stages based on the input moat, but the damping force characteristics may be divided into more detailed stages. In addition, in order to adjust to the heart soft holding tendency, we have shown a method of changing the switching base advance value ~・ref and a method of increasing/decreasing the soft holding time. The soft heart retention tendency may be changed by changing the coefficient by which the value is increased or decreased.

These switching procedures can be freely set to a heart retention tendency or a soft retention tendency by changing the parameters used in the switching procedures disclosed in JP-A-64-67407 or JP-A-1-202512. can do.

The present embodiment has a processing procedure in which the switching reference values ~'refi(i·1-3) used in switching procedures 1-3 are updated as a result of learning. A learning procedure for this purpose is stored in the storage means 202f, and parameters used in this process are stored in the storage means 202g.

When a vehicle travels on a good road for a long time, passengers gradually become accustomed to the comfortable ride and become sensitive to even the slightest impact. For this reason, when driving on a good road for a long time, it is preferable that the shock absorber switching procedure be learned over time in a direction that emphasizes riding comfort, that is, a direction that has a strong tendency to maintain softness. On the other hand, when driving at high speed on rough roads for a long period of time, it is preferable that the system learns more and more towards the hard hold tendency.

Figure 3 shows the processing procedure to achieve this.
In step S2, a learning reference value V refG used to determine whether to increase or decrease the switching reference value V ref is calculated. Here, V refG is the switching reference value Vref multiplied by ki, which is a constant of 1 or less, and ki(i
are integers from 1 to 3) are stored in the parameter storage means 202g as unique to the switching procedures 1, 2, and 3, respectively. Here, different values for ki are used in the hard state and the soft state for each switching procedure, and Vref and VrefG have a relationship as illustrated in FIG. 4.

Now, in step S4, the damping force change rate or learning reference value V
This is a process of counting the number of times that refG is exceeded for each unit time, and as a result, the number of times the frequency exceeds refG is counted as shown in the frequency column of FIG.

Step S6 is a process of comparing this count number Ci with the optimum frequency Nrefi for learning, and this Nrefi(i
・1 to 3) are also used as different values for each switching procedure 1 to 3.

As a result of step S6, the count number Ci is the optimum frequency Nre.
If it is determined that the current Vref is greater than or equal to fi, the current Vref is too small compared to the actual driving condition (either a tendency to maintain softness or a state where the vehicle posture is unsatisfactory due to being too strong).
Increase ref by αi (i·1 to 3). Here again, a different value for αi is used for each switching procedure.

If the count number Ci is less than the optimum frequency Nrefi in step $6, V ref is set to βi ( For i=1 to 3, decrease by β>0). Here again, different values of βi are used for each of the switching procedures 1 to 3.

The above processing is shown in FIGS. 4(A) and 4(B), where (A) shows the case when the vehicle is traveling on a good road, and (B) shows the case when the vehicle is traveling on a rough road.

Here, for example, when autodrive is turned on, the vehicle is traveling on a good road, so switching procedure 3, which has a strong tendency to maintain the software, is selected.

In this case, it is preferable that the soft retention tendency becomes stronger over time.

To do this, when autodrive is on, increase the amount of change (β3) when changing the learning result switching reference value V ref3 to the smaller side, and decrease the amount of change (α3) to change it to the larger side. Bye.

On the other hand, when driving on a rough road, switching procedure 1 is selected, so in the learning procedure of this switching procedure 1, the value (α1) when increasing Vrefl is thick (the value when decreasing Vrefl (β1)) is preferably small.

In this embodiment, different optimum parameters are used for each switching procedure in the learning procedure, so that even better learning effects can be obtained.

Here, in order to change the mode of learning to match the mote, the amount of correction by learning (α) as described above.

In addition to increasing or decreasing β), it also increases or decreases the allowable range of switching reference values (minimum and maximum values of Vref) that can be increased or decreased by learning, or determines whether or not to make corrections based on the learning results. It is also possible to increase or decrease the switching frequency number Nrefi.

By switching the learning procedure in accordance with the driving mode in this way, it becomes possible to more appropriately match the vibration damping system and the overall driving characteristics of the vehicle.

``Effects of the invention-: Now, according to the suspension control device of the present invention, 4~'
Since the damping force characteristics are switched in a manner that matches other systems that control the driving characteristics of the vehicle, such as S or ECT, the overall driving characteristics of the vehicle can be adjusted in a variety of ways that match all systems. can.

[Brief explanation of the drawing]

Fig. 1 is a diagram schematically showing the concept of the present invention, Fig. 2 is a diagram showing a system configuration of an embodiment, Fig. 3 is a diagram showing a processing procedure for learning the switching reference value, and Fig. 4 is a diagram showing the progress of learning. Figure 3

Claims (1)

[Scope of Claims] A driving characteristics control system capable of switching the driving characteristics of a vehicle, a shock absorber capable of changing the damping force characteristics between hard and soft states, and a shock absorber capable of changing the damping force characteristics of the shock absorber. In a vehicle having a controller, means is added for inputting a signal indicating a state in which the driving characteristic control system is switched to the shock absorber controller, and the shock absorber controller is provided with a mode corresponding to the input signal. 1. A suspension control device comprising a built-in storage means for storing a switching procedure for switching the damping force characteristics of the shock absorber.