JPS61184112A - Vehicle controller - Google Patents

Abstract

PURPOSE:To improve the comfortability by detecting the degree of pitching of vehicle in accordance to the detected rotary angle of stabilizers arranged on the front and rear wheels and modifying the suspension characteristic of variable suspension means upon detection of pitching higher than predetermined level. CONSTITUTION:In a vehicle C where stabilizers S are arranged on the front and rear wheels F, R while variable suspension means M for modifying the suspension characteristic is arranged between the body B and the front wheel and/or rear wheel R, two stabilizer rotation detecting means MA for detecting the rotary angle approximately in the center of respective stabilizer S are provided. While means MB for detecting the degree of pitching of vehicle C on the basis of the detected results from said means MA is provided. Upon detection of pitching higher than predetermined level through said means MB, characteristic modifying means MC will modify the suspension characteristic of the variable suspension means M.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vehicle control device that prevents pitching in order to improve the ride comfort and maneuverability of a vehicle. Various suspension controls are implemented to improve maneuverability. One of these is to prevent so-called pitching, in which the vehicle tilts back and forth, and the following devices have been proposed for this purpose.

First, the damping force of the shock absorber is increased by detecting conditions where pitching occurs. The most common types of pitching include skidding when a vehicle suddenly starts and diving when braking at high speed. Therefore, a high-speed sensor or the like is installed in the vehicle, and when sudden acceleration/deceleration exceeding a predetermined value is detected, the damping force of a shock absorber or the like is increased.

Other devices control vehicle suspension by detecting pitching actually occurring in the vehicle. That is, unlike the above-described devices, pitching actually occurring in the vehicle is detected using vehicle height sensors for the front wheels and rear wheels, and suspension control is executed in accordance with the detected values.

Problems to be Solved by the Invention] However, the above-mentioned conventional methods have the following problems and are still not satisfactory.

In other words, a system that detects vehicle acceleration, which is a condition for pitching, and changes its suspension characteristics, uses a vehicle speed sensor, etc. that is conventionally installed in the vehicle, so it is inexpensive and has a simple configuration. However, it is impossible to detect other types of pitching that are not caused by acceleration, such as pitching when driving on rough roads, and the purpose cannot be fully achieved.

Furthermore, those that use a vehicle height sensor have the advantages of the above technology as disadvantages and the disadvantages as advantages.

Since the vehicle height is measured as a solid line, it is possible to detect pitching under any conditions and use it as a control target. However, when vehicle height sensors are installed on the left and right front and rear wheels, and the vehicle height sensor detection results of the left and right wheels are averaged to find the average height of the front or rear wheels, the vehicle height of the front and rear wheels cannot be calculated. In order to detect the difference and pitching, not only a plurality of new vehicle height sensors were required, but also the processing of their output was complicated.

The present invention has been made to solve the above problems,
It is an object of the present invention to provide an excellent vehicle control device that accurately detects a pitching phenomenon and improves ride comfort and maneuverability of a vehicle despite its simple configuration.

[Means for solving the problems] The means configured by the present invention to solve the above problems are as follows:
As shown in the basic configuration diagram in Figure 1, front wheel F and rear wheel R
A vehicle control device for a vehicle comprising a stabilizer S at the front wheels F and/or a variable suspension means M capable of changing suspension characteristics between the front wheels F and/or the rear wheels R and a body B of the vehicle C, Two stabilizer rotation detection means M for detecting the rotation angle of the substantially central portion of each stabilizer S of the rear wheel R
A, a pitching detection means MB that detects the pitching degree of the vehicle from the detection results of the two stabilizer rotation detection means MA, and a pitching detection means MB that detects the degree of pitching of the vehicle from the detection results of the two stabilizer rotation detection means MA; The gist of the present invention is a vehicle control device characterized by comprising a characteristic changing means MC for changing suspension characteristics.

[Operation] The stabilizer rotation detection means MA in the present invention detects how much the substantially central portion of the stabilizer S is rotated with respect to the vehicle body B of the vehicle C. As is well known, the stabilizer S is a rigid body that connects the left and right wheels, and when centrifugal force is applied to the vehicle, a torsional force is applied to the rigid body due to a change in vehicle height between the left and right wheels, and it creates a restoring force against the torsional force. This reduces the vehicle's oil consumption. Therefore, only a twisting force acts on the stabilizer S when the vehicle height changes between the left and right wheels, and the substantially central portion thereof does not rotate. When both the left and right wheels change the vehicle height in the same phase, the rigid body simply rotates without producing any force. Therefore, the stabilizer rotation detection means MA of the present invention detects the rotation angle of the substantially central portion of the stabilizer S, and quantitatively detects the in-phase change in vehicle height occurring in both the left and right wheels. Further, this stabilizer rotation detection means MA is provided in each of the stabilizers S of the front wheel F and the rear wheel R. For example, its configuration is as follows:
The rotation angle of the stabilizer S may be detected by mechanical contacts or non-contact by an optical rotary encoder or the like.

The pitching detection means MB detects vehicle pitching from the detection results of the two stabilizer rotation detection means MA described above. One stabilizer rotation detection means MA is the front wheel F.
Alternatively, the vehicle height change of the left and right rear wheels R is detected in the same phase, and the difference between the detection results of the two stabilizer rotation detection means MA is the difference between the average vehicle height of the front wheels F and the average vehicle height of the rear wheels R. In other words, it becomes pitching. Therefore, the pitching detection means MB calculates the difference between the detection results of the stabilizer rotation detection means MΔ in order to detect pitching, or calculates the amount of change in the difference in order to detect the degree of occurrence of pitching. The pitching occurring in the vehicle C is detected by performing the following information processing.

Further, the characteristic changing means MO operates the variable suspension means M of the vehicle C to appropriately change the suspension characteristics when it is determined that the pitching quantitatively detected as described above is equal to or higher than a predetermined value. . Here, the predetermined value is a value at which pitching occurring in the vehicle C adversely affects ride comfort and maneuverability, and is appropriately selected by taking into consideration, for example, the wheel base, superposition, suspension characteristics, etc. of the vehicle C. . Further, the suspension characteristics can be changed by, for example, changing the spring constant or changing the damping force of the shock absorber.

EXAMPLES Hereinafter, in order to explain the present invention more specifically, the present invention will be described in detail by giving examples.

[Embodiment] FIG. 2 is a schematic diagram of a suspension configuration of a vehicle equipped with a vehicle control device according to an embodiment of the present invention.

In the figure, IL, 1R are the front left and right wheels of the vehicle, and 2L, 2
R represents the rear left and right wheels, 1L, 1R, 12L, and 2R.
are connected by a stabilizer 3F or 3R, respectively. Rotation angle sensors 4F and 4R, which will be described later, are attached to the center of each stabilizer 3F and 3R, respectively, and the detection results thereof are input to an electronic control unit 30 mainly including a microcomputer. The following suspension devices are installed between the vehicle body and front wheels IL, 1R and between the vehicle body and rear wheels 2L, 2R. First, to explain the front wheels, the aforementioned front wheels 1L and 1R are rotatably attached to both ends of a front wheel 5, which is connected to a steering shaft (not shown) and swings in response to rotational operation of the steering wheel. Furthermore, coil springs 7 are installed at both ends of this front wheel 5.

One end of a suspension support including shock absorbers 9L and 9R is attached to the center shaft of 7R. Further, a vehicle body is supported on the other ends of the shock absorbers 9L and 9R. As a result, the front wheel is 1L, and the IR shock is a 7L coil spring.

The shock absorbers 7R, 9L, and 9R absorb and attenuate the shock, respectively, ensuring good maneuverability and ride comfort for the vehicle.

The rear wheels 2L and 2R are rotatably attached to shafts that are rotationally driven by an engine (not shown). And independent coil springs 11R, 11L and shock absorbers 13R, 13 are connected to the vehicle body.
L is interposed, and like the front wheel IL, 1R, the rear wheel 2L,
The shock to 2R is absorbed and attenuated.

Furthermore, shock absorbers 9L, 9R, and 13L are provided between the front and rear wheels and the vehicle body.

13R is capable of changing its damping force, and as shown in the figure, the upper actuator is actuated by a signal from the electronic control device 30, and the damping force is changed by changing the effective area of the flow path for oil flow and air flow. do.

FIG. 3 is an explanatory diagram of the structure of rotation angle sensors 4F and 4R that detect rotation angles of the center portions of stabilizers 3F and 3R.

(A) The figure shows a schematic structure, and as shown in the figure, there is a disk 41 that is fitted into the stabilizers 3F and 3R and has many slits around its circumference, and a disk 41 that is clearly shown in the A-A cross-sectional view. It consists of two members: the sensor 42; Further, 43 is a connector for transmitting the detection output to the electronic control device. This disk 41 is the stabilizer 3F.

It rotates together with 3R and changes its relative position with the sensor 42 attached to the vehicle body. An explanation of the principle of detecting the rotation of the disk 41 is shown in FIG. 3(B). As shown in the figure, two sets of optical sensors 42a and 42b are arranged with the disk 41 in between, and one of the optical sensors 42a and 42b serves as a light emitting section and the other serves as a light receiving section. Therefore, disk 4
1 rotation, each of the optical sensors 42a and 42b becomes an ON state (detecting light) or an OFF state (no light detection) through the slit as shown in the figure, and the rotation angle of the disk can be detected. Further, 44 is a light shielding plate for preventing disturbance from entering the optical sensors 42a and 42b.As shown in the figure, two sets of optical sensors 42a and 42b are provided, so that depending on the rotation direction of the disk 41, Each optical sensor 42
The phases of the ON and OFF states of a and 42b change, thereby making it possible to detect two pieces of information: the rotation direction and rotation angle of the disk 410.

FIG. 4 is a block diagram of the signal system of the vehicle control device of this embodiment, centering on the electronic control device 130. As shown in the figure, the electronic control unit [30 is composed of a digital circuit centered on a microcomputer, and is a Cable controller that executes logical operations.
PLI31 is in charge of control.

The program executed by the CPU 31 is stored in the ROM 32 in advance, and the CPU 3 executes the program according to the program.
RAM3 is used to store temporary information such as the results of logical operations performed by 1.
It will be held at 3. This electronic control device 30 receives two optical sensor outputs from the rotation angle sensors 4F and 4R described above via an input port 34. Then, the shock absorber 9L executes the processing described later on the input information and provides the best suspension characteristics for the vehicle.
When the damping forces of 9R, 13L, and 13R are calculated, a shock absorber actuator drive signal corresponding to the calculation result is outputted via the output port 35. Therefore, the input port 34 consists of a waveform shaping circuit, multiplexer, etc., and the output port 35 consists of a digital-to-analog converter, a signal amplifier, etc. Further, 36 is a path line that serves as a path for information transmission within the electronic control device i30.

The vehicle control device of this embodiment having the above configuration has a ROM
The pitching prevention routine stored in 32 and whose flowchart is shown in FIG. 5 operates as follows.

First, when the vehicle starts running, the CPU 31 starts processing this routine and inputs signals from the two rotation angle sensors 4F and 4R (step 100).

Then, from that input signal (pulse train), the front wheel 1L.

IR, how much the stabilizers 3F and 3R of the rear wheels 2L and 2R are rotated, and the angle θ1. Calculate θ2 (
Step 110). This angle θ1° θ2 is the amount of rotation occurring at the center of the stabilizers 3F, 3R, and its value is proportional to the average amount of change in height between the front wheels 1m, 1R1 and the rear wheels 2L, 2R. That is, when the vehicle height changes with different phases between the left and right wheels, so-called rolling, a torsional force acts on the stabilizer 3L or 3R to cancel out the difference in vehicle height between the two wheels, and no rotation occurs in the center portion thereof. However, when the vehicle heights of the left and right wheels change in the same phase, the stabilizer 3L or 3R only rotates and does not have any effect on the two wheels.

The rotation angle sensors 4F and 4R are connected to the stabilizer 3L or 3.
By detecting only the rotation angle of R, it is possible to easily extract only information about vehicle height changes occurring in the same phase on both left and right wheels. Therefore, in the following step 120, the detected 2
rotation angle θ1. The pitching angle θP occurring in the vehicle is calculated from θ2 using the following equation.

θP-(A・θ+-B・θ2)/Tachi where Tachi is the wheelbase length of the vehicle, and constants A and B represent how much the vehicle height changes depending on the rotation angle of the stabilizers 3L and 3R, respectively. A・θ1
Front wheel 1. Vehicle height change of L and 1R is rear wheel 2L at B・θ2
, 2R vehicle height change is calculated. Since the pitching that occurs in the vehicle becomes uncomfortable for the occupants and has a negative impact on maneuverability, it is when the pitching angle θP changes rapidly that the pitching angle θP is differentiated, the so-called pitching angular velocity, in step 130. θ°P is calculated and used as the target of the following control. Once the input signals from the rotation angle sensors 4F and 4R are processed in this way and the pitching angular velocity θP is determined, it is then determined whether the actually measured pitching angular velocity θ°P is at a level that causes discomfort to the passenger. is compared with the upper limit value MAX of pitching angular velocity stored in advance in the ROM 32 (step 140).
. Then, if θ°P≦MAX, the above actual measurement process (steps 100 to 130) is repeatedly executed, and θ”P >
MAX, and if it is determined that some kind of control is required, the following steps 150 to 190 are executed.

Note that the upper limit value MAX of θP at this time is a value unique to the vehicle, for example, set to be large in proportion to the pitching moment of inertia of the vehicle.

In step 150, the counter C is incremented. This is to measure the time to continue the control to increase the damping force of the shock absorbers 9L, 9R, 13L, and 13R, which will be executed in the next step 160, and the value of the counter C will be stored in the ROM 32 in the following step 170. Steps 150 to 170 are repeatedly executed until it is determined that the damping force is larger than the predetermined value CC, and the damping force continues to be set large. The time period during which the damping force is maintained at a high level by the counter C is appropriately selected, for example, by setting it to be long in proportion to the wheel base of the vehicle. When it is determined in this step that C>CC, the shock absorber 9L is
, 9R, 13L.

The damping force of 13R returns to the normal state, the counter C is reset in preparation for the next control (step 190), and step 100 is processed again.

As described above in detail, according to the vehicle control device of this embodiment, pitching of the vehicle can be detected accurately and quickly by simply providing the two rotation angle sensors 4F and 4R in the detection system, and the pitching of the vehicle can be detected accurately and quickly. As soon as the pitching angular velocity θP that is felt to be uncomfortable is detected, the suspension characteristics of the vehicle are optimally controlled.

In this embodiment, the pitching angular velocity θ°P is controlled, but the pitching angle θP may be used to control the levelness of the vehicle. Furthermore, for the damping force control of the shock absorbers 9L, 9R, 13L, and 13R, one stage of constant time control is mentioned for the sake of clarity, but the damping force is controlled in multiple stages, and the control time is also □Techniques such as learning from past control situations and making decisions may also be applied.

[Effects of the Invention] As described above in detail with reference to the embodiments, the vehicle control device of the present invention includes stabilizers for the front wheels and the rear wheels, and a stabilizer between the front wheels and/or the rear wheels and the body of the vehicle. A vehicle control device for a vehicle having a variable suspension means capable of changing the suspension characteristics of the front wheel and the rear wheel, comprising: two stabilizer rotation detection means for detecting rotation angles of substantially central portions of each of the front wheel and rear wheel stabilizers; Pitching detection means for detecting the degree of pitching of the vehicle based on the detection result of the rotation detection means; and characteristic changing means for changing the suspension characteristics of the variable suspension means when the pitching detection means detects pitching of a predetermined value or more. It is characterized by this.

Therefore, by simply equipping the front and rear wheel stabilizers with a simple detection means called stabilizer rotation detection means, it is possible to detect all types of pitching that occurs in the vehicle, including pitching that occurs regardless of vehicle acceleration. The detection result is in a proportional relationship with the vehicle height data, which does not require a complicated average value sieve or the like.

Therefore, the vehicle control device of the present invention has a simplified configuration;
Not only has reliability and durability been improved, but the control is also extremely responsive, making it an extremely excellent 1-car Ill III.
It will be in position a.

[Brief explanation of the drawing]

Figure 1 is a basic configuration diagram of the present invention, Figure 2 is a schematic diagram of the configuration of an embodiment, Figure 3 (A) is an explanatory diagram of the configuration of the rotation angle sensor, and Figure 3 (B) is the rotation angle sensor. Operation explanatory diagram, 4th
The figure shows a block diagram of the signal system, and FIG. 5 shows a flowchart of its control. S... Stabilizer M... Variable suspension means MA... Stabilizer rotation detection means MB... Pitching detection means MC... Characteristic changing means 3F, 3R... Stabilizers 4F, 4R... Rotation angle sensor 9R, 9L, 13R, 13L...Shock absorber 30...Electronic control device Fig. 3 (A) (B)

Claims (1)

[Scope of Claims] A vehicle control device for a vehicle including stabilizers on front wheels and rear wheels, and variable suspension means capable of changing suspension characteristics between the front wheels and/or the rear wheels and the vehicle body, two stabilizer rotation detection means for detecting rotation angles of substantially central portions of each of the front wheel and rear wheel stabilizers; pitching detection means for detecting the degree of pitching of the vehicle from the detection results of the two stabilizer rotation detection means; A vehicle control device comprising: characteristic changing means for changing suspension characteristics of the variable suspension means when the pitching detecting means detects pitching of a predetermined value or more.