JPH08287398A - Vehicle guidance device - Google Patents

Abstract

PURPOSE: To surely guide a vehicle to a garage regardless of an initial location and an attitude angle, in a guide parking device for vehicle. CONSTITUTION: A vehicle location and an attitude angle are detected by a detection means and forwarding/backwarding is decided by a decision means 2. An arithmetic means 4 such as an electronic controller E, etc., controls the steering of a vehicle so as to be located on the guideline set by a guideline setting means 3 based on a prescribed relational expression. A gain change means 6 changes the gain f1 of a location and the gain f2 of the attitude angle in the relational expression according to the location and the attitude angle and supplies the gain to a control means 5. In the change of the gain, the gain map stored in a storage means 7 is used. The calculated steering angle is supplied to the control means 5 and a steering control is performed. Because the gain is not fixed and is changed according to the location and the attitude angle, various kinds of locations and attitude angles can be coped with.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle guidance system, and more particularly to a vehicle guidance control system based on modern control theory.

[0002]

2. Description of the Related Art Conventionally, an automatic parking system for parking a vehicle at a predetermined position by automatic control is known.

For example, Japanese Patent Application Laid-Open No. Hei 5 (1994) proposed by the present applicant.
-19853 discloses a so-called modern control theory in which a state variable of a system is used for control, unlike classical control in which an input value is changed according to a deviation between an output value and a target value when a certain system is stably controlled. An automatic parking device using is disclosed. In this device, the position Yp and the posture angle θp of the vehicle with respect to the parking section are detected, and the guideline is gradually set according to the detected position, posture angle and forward / backward movement, and the vehicle is positioned on the set guideline. Thus, the steering angle α of the vehicle is

## EQU1 ## α = tan ^-1 [Lcos ³ (θp) {f1Yp-f2tan (θp)}] ··· (1) When traveling backward:

## EQU2 ## α = tan ^-1 [Lcos ³ (θp) {f1Yp + f2tan (θp)}] ... However, L is the wheel base of the vehicle, and f1 and f2 are constants. In addition,
The guideline is not fixed to the center line of the garage or the like, but is gradually set so that the posture angle of the vehicle with respect to the guideline is less than 90 degrees.

According to this device, the initial posture angle of the vehicle is 9
It is possible to guide on a desired track even if it is near 0 degrees or more, and even when the vehicle shifts from reverse to forward for turning back, steering is controlled according to the guideline, so it is excellent in flexibility. It has become a system.

[0005]

However, the applicant of the present application, as a result of studies using this device in various situations, found that the optimum guided parking may not always be achieved.

FIGS. 6 and 7 show two types of induction parking of the conventional device.
Two orbit examples are shown. FIG. 6 shows a case where the vehicle position is close to the center line of the parking area (garage) and the posture angle is close to 0 degree. On the other hand, FIG. 7 shows that the vehicle is located near the minimum turning radius and the posture angle is near 90 degrees. Is the case. In the case as shown in FIG. 6, if the gains f1 and f2 in the above equations (1) and (2) are set too high, the correction steering cannot be overtaken as the vehicle speed increases as shown in the figure. Hunting will occur. Therefore, in order to smoothly perform automatic parking, the gains f1 and f2 are
Needs to be set to a low value to some extent, but if the gain is lowered, then it becomes difficult to park near the minimum turning radius in the case of FIG. 7, and in the worst case, there will be a problem that parking is impossible.

That is, in the conventional device, it is difficult to adapt to both the situations shown in FIGS. 6 and 7, and the gain is set in accordance with the vehicle position and the attitude angle which may occur most frequently. f1, f2) = (-14, 15)
However, there is a problem in that it is necessary to take measures such as setting the above (of course, even if the gain is set in this way, the problems shown in FIGS. 6 and 7 still occur).

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a more adaptive induction parking apparatus capable of coping with various positions and attitude angles than ever before. is there.

[0009]

In order to achieve the above-mentioned object, the present invention is based on the position and attitude angle of a vehicle with respect to a guidance section such that the vehicle is positioned on a guideline preset for the guidance section. In a vehicle guidance device for guiding a vehicle to a guidance section by controlling a steering angle of the vehicle based on a predetermined relational expression, a detection means for detecting a position and an attitude angle of the vehicle with respect to the guidance section, and a vehicle in the predetermined relational expression And a gain changing unit that changes the gains of the position and the posture angle according to the detected position and the posture angle.

[0010]

As described above, according to the present invention, the gains f1 and f2 in the equations (1) and (2) are not fixed as constants as in the conventional apparatus, but are appropriately changed according to the vehicle position and the attitude angle. . For example, as shown in FIG. 6, when the position is near the center line of the guidance section and the posture angle is close to 0 degree, the gain is set relatively low, and conversely, as shown in FIG. 7, the posture angle is near the minimum turning radius. If the value is close to 90 degrees, the gain is set relatively high. As a result, the vehicle can be smoothly guided to the guidance section under any circumstances.

As a method of changing the gain, a method of uniquely setting the gain according to the initial position and the attitude angle of the vehicle, or a method of constantly monitoring the position and the attitude angle changing with the movement of the vehicle, A method is considered in which the gain is sequentially changed according to the position and posture angle at that time.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a conceptual block diagram of the apparatus in this embodiment. The detecting means 1, the judging means 2, the guideline setting means 3, the calculating means 4 and the controlling means 5 are the same as those of the above-mentioned Japanese Patent Laid-Open No. 5-19853. That is, the vehicle position Yp and the attitude angle θp with respect to the parking section
Detecting means 1 for detecting the vehicle speed, determining means 2 for determining whether the vehicle is moving forward or backward, and the attitude angle of the vehicle with respect to the guideline is 90 degrees according to the detected position Yp and attitude angle θp and forward / backward movement. The guideline setting means 3 for gradually setting the guideline so as to be less than the vehicle, and the vehicle according to the above equations (1) and (2) according to the position, the attitude angle, and the forward / backward movement so that the vehicle is positioned on the set guideline. And a control means 5 for controlling the steering of the vehicle on the basis of the calculated steering angle. For the calculation process of equations (1) and (2), refer to the above-mentioned Japanese Patent Laid-Open No. 5-19853.

Further, in this embodiment, the gain changing means 6 for changing the gains f1 and f2 based on the position Yp (x, y) of the vehicle detected by the detecting means 1 and the attitude angle θp, and the position and attitude angle in advance. The gain (f1, f
Storage means 7 is provided for storing 2) as a map.
When the detection signal is input from the detection unit 1, the gain change unit 6 accesses the storage unit 7, reads the gains (f1, f2) corresponding to the detected position and posture angle, and supplies the gains (f1 and f2) to the calculation unit 4. In the calculation means 4, the gain changing means 6
The steering angle α is calculated by performing the calculations shown in the equations (1) and (2) using the gain input from

FIG. 2 shows a specific construction of the induction parking system of this embodiment. A garage position sensor 10 is provided to detect the position and attitude angle of the vehicle. Further, a vehicle speed sensor 12 is provided, and detection signals from the garage position sensor 10 and the vehicle speed sensor 12 are both supplied to the parking ECU 14. Further, the parking ECU 14 determines whether the vehicle is moving forward or backward based on the detection signal from the shift lever switch 16. Parking E
The CU 14 calculates the steering angle α by the equations (1) and (2) based on the detection signal, and the steering ECU as a control signal.
The steering ECU 20, which is supplied to 20, drives a steering actuator 22 to perform steering control. The state of the garage is displayed on the TV monitor 18,
It can be confirmed by the driver.

The characteristic of this embodiment is that the parking E
The CU 14 is to change the gains f1 and f2 according to the vehicle position and the attitude angle, and generally changes the gains as follows.

(1) A low gain is used when the vehicle position is close to the garage center line and the attitude angle is close to 0 degrees.

(2) The vehicle is located near the minimum turning radius,
A high gain is used when the posture angle is near 90 degrees.

Note that (1) aims to reduce hunting to smoothly guide the vehicle to the garage, and to slow the correction steering to make it less susceptible to changes in vehicle speed, and (2) quickly. The aim is to bring the vehicle closer to the garage centerline and to park at a minimum turning radius.

Under these conditions, as a constraint condition for parking the vehicle in the garage, (a) lateral displacement ± 30c from the garage entrance to -2m.
Attitude within ± 3 degrees within m (b) Simulation at each position and attitude using lateral displacement within ± 10 cm and attitude angle within ± 2 degrees at final parking position (-3.8 m from garage entrance) And then
The lowest gain combination among the resulting gain combinations is adopted. The lowest gain is adopted because this is the gentlest track, the steering amount is small, and the vehicle speed fluctuation is strong.

FIG. 3 shows an example of the gain map thus obtained. In the figure, the vertical axis represents the garage center line, the horizontal axis represents the distance from the center line, and the gain is determined as follows.

Area I: When the attitude angle is 140 degrees or less (f1, f2) = (-17, 20) When the attitude angle is 140 degrees or more (f1, f2) = (-10, 20) Area II: ( f1, f2) = (-15, 19) Region III: (f1, f2) = (-11, 23) Region IV: (f1, f2) = (-13, 20) Region V: (f1, f2) = (-12, 20) Region VI: (f1, f2) = (-18, 22) Region VII: (f1, f2) = (-15, 20) Region VIII: (f1, f2) = (-2, 10) ) Region IX (inside garage): (f1, f2) = (-11, 25). Although the gain value is shown only in the left region with respect to the center line in the figure, the gain value in the right region is the same as that in the left region. Moreover, these values are not absolute values but representative values, and values in the vicinity thereof can be used.

FIGS. 4 and 5 show an example in which the gain is determined using the gain map thus determined and the steering control is actually performed. However, in this example, the gain is determined depending on which of the regions I to IX the initial position and the posture angle correspond to, and the gain value once determined is not changed until the automatic parking is completed. FIG. 4 shows the initial position and orientation corresponding to FIG. 6 of the related art, where (f1, f2) = (− 14, 1)
It is a locus in the case of (f1, f2) = (-2, 10) with respect to 5), and it can be seen that the vehicle can be smoothly guided to the garage without causing hunting even near the center line. Also, FIG.
Is the initial position and posture angle corresponding to FIG. 7 of the related art, and (f1, f2) = (-14, 15) of the related art
2) = (− 10, 20) is the trajectory, and it can be seen that the vehicle can surely be guided to the garage by turning with the minimum turning radius.

By comparing FIGS. 4 and 5 with conventional FIGS. 6 and 7, respectively, the effect of changing the gain will be apparent.

In the present embodiment, the gain value is changed using the gain map shown in FIG. 3, but the region of FIG. 3 is not fixed, and the gain is divided into smaller regions as necessary. It is also possible to determine It is also conceivable to calculate the gain value as a function of the position and the attitude angle instead of the gain map.

Further, in the present embodiment, the gain value is determined based on the initial position and the posture angle, and the gain is kept constant during the steering control, but it corresponds to the position and the posture angle which change every moment when the automatic parking control is performed. It is also possible to read the gain value from the map and sequentially change the gain value. However, in this case, in order to smoothly perform the guided parking, in the method using the gain map, the area is finely divided, and the gain value is set so that the gain value changes substantially continuously between the adjacent areas. More processing is required.

[0027]

As described above, according to the present invention, it is possible to provide a vehicle guidance device which can cope with various positions and posture angles more than ever, and which is more adaptable.

[Brief description of drawings]

FIG. 1 is a conceptual configuration diagram of an embodiment of the present invention.

FIG. 2 is a specific configuration diagram of the embodiment.

FIG. 3 is an explanatory diagram of a gain map of the embodiment.

FIG. 4 is an orbit explanatory diagram showing an example of induction parking of the embodiment.

FIG. 5 is a trajectory explanatory view showing another example of the guided parking of the embodiment.

FIG. 6 is a trajectory explanatory view showing an example of induction parking by a conventional device.

FIG. 7 is an orbital explanatory view showing another example of guided parking by the conventional device.

[Explanation of symbols]

1 detecting means, 2 judging means, 3 guideline setting means, 4 computing means, 5 control means, 6 gain changing means,
7 storage means, 10 garage position sensor, 12 vehicle speed sensor, 14 parking ECU, 16 shift lever switch,
18 TV monitor, 20 Steering ECU, 22
Steering actuator.

Claims (1)

[Claims] 1. A steering angle of a vehicle is controlled based on a predetermined relational expression according to a position and an attitude angle of the vehicle with respect to the guidance section so that the vehicle is positioned on a guideline set in advance for the guidance section. In a vehicle guidance device for guiding to a guidance section, a detection unit that detects a position and a posture angle of the vehicle with respect to the guidance section, and a gain of the position and the posture angle of the vehicle in the predetermined relational expression are determined according to the detected position and the posture angle. A vehicle guidance device comprising: