JP2719728B2 - Vehicle control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] Regarding a vehicle control device that performs feed-forward (F / F) control, grasps in advance the state of the road on which the vehicle is traveling, and responds by reflecting it in the control amount. The purpose of the present invention is to improve vehicle performance and to enable vehicle control close to manual operation by a driver. In a vehicle control device that controls each part of the vehicle in accordance with the output of various sensors, the current position and the traveling direction of the vehicle are determined. A sensor for detecting, based on the current position and the traveling direction of the vehicle detected by the sensor, reading means for reading information indicating a state of a road on which the vehicle travels from road information storage means which stores in advance, Feed forward control means for controlling each section of the vehicle in accordance with the road condition of the information read by the read means.

[Industrial applications]

 The present invention relates to a vehicle control device that performs F / F control.

Vehicles such as a constant speed traveling control device that keeps the traveling vehicle speed constant, a transmission control device that automatically changes the transmission gear ratio (reduction ratio), and a suspension control device that changes the strength of the suspension according to the road surface condition Control devices tend to be more and more popular in order to enhance the operability of the vehicle and improve the riding comfort.

[Conventional technology]

The above-described vehicle control device detects a current state by a sensor and performs a feedback (F / B) control that reflects the current state in a control amount. For example, the constant-speed traveling control device detects a current traveling vehicle speed by a sensor and controls the throttle opening by an actuator so as to reduce a difference between the detected traveling vehicle speed and a target vehicle speed.

FIG. 4 shows a simple control loop of the conventional constant speed traveling control. The vehicle speed sensor 1 detects the traveling speed of the vehicle body 2. When the output of the sensor 1 is stored in the memory 3 at a certain point in time, it becomes the target vehicle speed, and the arithmetic unit 4 calculates the difference (vehicle speed deviation) between the target vehicle speed and the traveling vehicle speed at each time. F /
The B control calculates the operation amount so as to reduce the vehicle speed deviation. In general, the basic operation amount corresponding to the target vehicle speed is mapped to a map 5.
And the operation amount in the stable state is set to the basic operation amount. Then, the arithmetic unit 6 adds (decreases) the correction amount calculated from the vehicle speed deviation to the basic operation amount to calculate a final operation amount for driving the actuator 7. Since the actuator 7 of the present embodiment adjusts the opening of the throttle 8, when the opening changes, the rotation speed of the engine 9 changes, and accordingly, the traveling vehicle speed of the vehicle body 2 changes via the transmission 10. An F / B loop is formed in which the vehicle speed deviation is reduced.

[Problems to be solved by the invention]

Before the operation amount of the actuator 7 changes in the F / B control system shown in FIG. 4, the traveling vehicle speed must change before that. For example, if you approach an uphill while traveling at a constant speed, the vehicle speed will eventually decrease unless you open the throttle, but in F / B control the throttle will open or shift down after waiting for the result that the vehicle speed actually decreases. Therefore, it cannot be avoided that the vehicle speed decreases even temporarily.
In order to shorten this time, the loop gain may be increased, but on the other hand, the stability of the system is reduced and the riding comfort is deteriorated. Therefore, in general, a certain time constant is given to slowly change the vehicle speed. I do.

In such a case, the driver can see the uphill slope and foresee the subsequent decrease in vehicle speed, so before approaching the uphill slope, depress the accelerator pedal to open the throttle or shift down to avoid the decrease in vehicle speed. I do. On the other hand, since the F / B control described above is a posteriori, there is no prior preparation based on such a prediction.

The present invention is intended to improve the responsiveness of automated vehicle control by adding F / F control using road information such as climbing hills, and to achieve control contents that feel human.

[Means for solving the problem]

FIG. 1 is a block diagram of the present invention, in which 20 is a navigation system, and 30A to 30C are various vehicle control devices. That is,
30A is a cruise controller for constant-speed running control that drives the actuator 7 to adjust the opening of the throttle 8 so that the running speed at each time obtained from the vehicle speed sensor 1 approaches the target speed, and 30B is the transmission 10 (for example, A transmission controller that maps and controls the reduction ratio of the continuously variable transmission (CVT) from the relationship between the vehicle speed and the throttle opening.
This is a suspension controller that changes according to the road surface condition (unevenness) obtained from the sensor 12.

This type of controller 30 is all configured to perform F / B control, but in the present invention, this
Add F / F control. The navigation system 20 reads a segmented map of a traveling area from a map information storage means (for example, a CD-ROM) 21 and displays it on a display (for example, an LCD) 22, while the azimuth sensor 13 and the steering angle sensor 14 show the vehicle. It has a function of detecting a position and displaying the position on the map of the display 22 in a superimposed manner. In the present invention, the storage means 21 stores road information (location information) such as road gradient, road surface condition (unevenness), curve curvature, etc. for each point, accesses this at the own vehicle position, and develops it in the memory 23. Let the controller 30 use it.

[Action]

The controller 30 is connected to the F / F control means 31 as shown in FIG.
It has a control means 32, and in the F / B control, an F / B correction value based on past information such as a vehicle speed obtained from a control target is added to the basic operation amount, whereas the F / F control is based on the location information of the current position. The F / F correction value is added to the basic manipulated variable.

Since the location information is that of the current position, for example, if the user goes uphill while traveling at a constant speed, it is possible to perform F / F control that immediately opens the throttle opening (before the vehicle speed decreases). With this type of F / F control, the F / B control requires only a small amount of correction, resulting in excellent responsiveness and the ability to continue traveling at a constant speed without a decrease in vehicle speed even when moving from flat ground to uphill. it can. The same applies to other controls, whereby a human-like operation feeling similar to the operation by the driver can be provided. In this case, F / B control is used together to stabilize the system.

〔Example〕

FIG. 3 is a flowchart showing one embodiment of the present invention.
(A) shows a main routine when each of the controllers 30A to 30C in FIG. 1 is realized by one microcomputer, and (b) shows location information (road information) transmitted from the navigation system 20 by the microcomputer. 4 shows a serial interrupt process received by a computer.

The main routine of (a) includes steps S10,..., S20 to S2.
.., S30, and S31. When the basic operation amount of each controller is calculated in step S10, road information is determined in steps S20, S23, and S27. This road information is (b) step
It was received at S40.

In step S20, it is determined whether or not the vehicle is on a slope. If the vehicle is on a slope, an F / F correction amount for increasing the throttle opening α times the flat ground for the cruise controller 30A is calculated in step S21. An F / F correction amount for increasing the reduction ratio by β times for the controller 30B is calculated. α is a function α = f (θ) of the gradient θ.
If it is a downhill, α <1. β is also a function of θ, β = g
(Θ).

In step S23, it is determined whether or not the vehicle is on a curve. If the vehicle is on a curve, the vehicle height outside the curve is increased by γ times the straight road in step S24, and the suspension is hardened in step S25. These are all suspension controllers 30
For C, γ is a function of vehicle speed V and curve radius R γ = h (R / V)
And The following step S26 is for the transmission controller 30B. Here, the reduction ratio is set to δ times of the straight road. This is also assumed to be a function δ = P (R / V) of R and V. In addition, R /
Control to change the steering angle by V is also possible.

In step S27, it is determined whether or not the road surface is uneven. If so, in step S28, the suspension is made softer than a flat road.

After the above F / F control, predetermined F / B control is performed in step S30 to stabilize the system, and in the next step S31, the final manipulated variable is output to each actuator.

In the above description, the road information to be used is based on the current position. However, road information of a point passing after n seconds can be used in consideration of the processing speed of the microcomputer and the operation delay of the actuator. This n seconds changes depending on the vehicle speed.

〔The invention's effect〕

As described above, according to the present invention, F / F control for detecting road information such as the gradient of a road on which a vehicle travels, road surface conditions, and the like, and correcting an operation amount for controlling each part of the vehicle according to the road information is performed. Introduced in vehicle control, it is possible to accurately control road information in advance, improve the stability and responsiveness of vehicle control, and automatically control various parts of the vehicle with the same human-like operation feeling as a driver. There are advantages that can be controlled.

[Brief description of the drawings]

FIG. 1 is a block diagram of the present invention, FIG. 2 is an explanatory diagram of the present invention, FIG. 3 is a flowchart of an embodiment of the present invention, and FIG. 4 is a block diagram of conventional constant-speed running control. In the figure, 8 is a throttle, 10 is a transmission, 11 is a suspension, 13 is an azimuth sensor, 14 is a steering angle sensor, 21
Denotes road information storage means, 31 denotes F / F control means, and 32 denotes F / B control means.

Claims (1)

(57) [Claims] A vehicle control device for controlling various parts of a vehicle according to outputs of various sensors, wherein a sensor (13, 1) for detecting a current position and a traveling direction of the vehicle.
4) reading means for reading information indicating the state of the road on which the vehicle travels from road information storage means (21) which stores in advance based on the current position and traveling direction of the vehicle detected by the sensor. And a feed-forward control means (31) for controlling each part of the vehicle in accordance with the road condition of the information read by the reading means.