JPH0738962Y2 - Unmanned vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to an unmanned vehicle that travels along a guide wire or a light reflector laid on the ground.

Conventional technology and its problems Conventionally, a pair of left and right steering control pickup coils, which are laid on the ground and travel along an induction wire in which an alternating current flows, are driven by separate drive motors. There is known an unmanned vehicle that includes drive wheels and in which the rotational speeds of both drive motors are controlled according to the difference or ratio of the induced voltages of a pair of pickup coils. However,
In such an unmanned vehicle, it is necessary to increase the rotation speed of one drive motor and decrease the rotation speed of the other drive motor in accordance with the difference or ratio of the induced voltages of both pickup coils. There is a problem that the circuit configuration is complicated.

An object of the present invention is to provide an unmanned vehicle having a simple drive control circuit configuration.

Means for Solving Problems The unmanned vehicle according to the present invention is provided symmetrically with respect to the center line of the vehicle body, and interacts with the conductor laid on the ground to detect a detection signal according to the distance from it. An unmanned vehicle having a pair of left and right steering control detectors and a pair of left and right drive wheels that are provided symmetrically with respect to the center line of the vehicle body and are driven by separate drive motors. Based on only the output signal of the right steering control detector among the output signals of the left and right steering control detectors, the drive motor has a rotational speed that increases as the distance between the right steering control detector and the inductor increases. The drive motor for the right-hand drive wheel is controlled to be slower, and the drive motor for the left-hand steering control is based on only the output signal of the left-hand steering control detector out of the left-right steering control detector output signals. The distance between the exit device and the derivatives and as characterized in that the rotational speed is controlled to be slower increase.

Effect of the Invention When the unmanned vehicle shifts to the left side with respect to the steering wheel, the distance between the steering control detector on the left side and the steering wheel increases, and the rotation speed of the drive motor for the right driving wheel slows down. Further, the distance between the steering control detector on the right side and the steering wheel is reduced, and the rotation speed of the drive motor for the left drive wheel is increased. As a result,
The left shift of the unmanned vehicle is corrected.

On the other hand, if the unmanned vehicle shifts to the right with respect to the steering wheel, the distance between the steering control detector on the left side and the steering wheel increases, and the rotation speed of the drive motor for the left drive wheel slows. In addition, the distance between the steering control detector on the left side and the guide becomes smaller,
The rotation speed of the drive motor for the right drive wheel is increased. As a result, the right shift of the unmanned vehicle is corrected. With such control, the unmanned vehicle travels along the guide.

Embodiments Embodiments in which the present invention is applied to an electromagnetic induction unmanned vehicle will be described below with reference to the drawings.

In this specification, the center line of the vehicle body refers to a straight line (M) extending in the front-rear direction passing through the center of the unmanned vehicle (1) in the width direction, as shown in FIG.

FIG. 1 shows an electromagnetic induction unmanned vehicle. Unmanned vehicle (1)
Is a front wheel (2) and a rear wheel (3) respectively attached to support members (not shown) rotatably attached to the front and rear portions of the lower surface of the vehicle body, and a center line ( M) is provided with a pair of left and right drive wheels (4L) and (4R) which are symmetrically provided. Then, the pair of drive wheels (4L) (4R) are respectively driven by different drive motors (5L
L) (5R) drive each drive motor (5L) (5R)
The unmanned vehicle (1) is steered by making a difference in the number of rotations of the unmanned vehicle (1). In addition, the center line (M)
A pair of left and right pickup coils (6L) (6R) are provided symmetrically with respect to.

A guide line (7) is laid along the traveling route of the unmanned vehicle (1) on the ground on which the unmanned vehicle (1) is to travel. An induction current having an appropriate frequency is applied to the induction wire (7). Then, the magnetic field generated by the current flowing through the induction wire (7) induces a voltage in the pickup coils (6L) (6R) according to the distance from the induction wire (7). That is,
The output voltage of the pickup coil (6L) (6R) decreases as the distance from the induction wire (7) increases.

FIG. 2 shows the electrical configuration of the traveling control circuit. The induced voltage VAL of the left pickup coil (6L) is amplified by the variable gain amplifier circuit (11) and then sent to the signal processing circuit (12). The signal processing circuit (12) extracts only the same frequency component as the frequency of the induction current flowing in the induction wire (7) from the input AC voltage, and amplifies, rectifies and smoothes the extracted AC voltage. DC voltage VD
Convert to L. The output voltage VDL of the signal processing circuit (12) is sent to the motor drive circuit (13) for the right drive motor (5R) as a speed command signal for the right drive motor (5R). Then, the right drive motor (5R) is rotationally driven at a speed according to the magnitude of the speed command signal VDL.

The induced voltage VAR of the right pickup coil (6R) is amplified by the variable gain amplifier circuit (21) and then sent to the signal processing circuit (22). The signal processing circuit (22) extracts only the same frequency component as the frequency of the induction current flowing in the induction wire (7) from the input AC voltage, and amplifies, rectifies and smoothes the extracted AC voltage. DC voltage
Convert to VDR. The output voltage VDR of the signal processing circuit (22) is
The speed command signal for the left side drive motor (5L) is sent to the motor drive circuit (23) for the left side drive motor (5L). Then, the left drive motor (5L) is rotationally driven at a speed according to the magnitude of the speed command signal VDR.

The outputs VDL and VDR of both signal processing circuits (12) (22) are also sent to the amplifier circuit (14). The amplifier circuit (14) uses the larger one of the two voltages VDL and VDR input to the amplifier circuit (14) as a gain control signal for both variable gain amplifier circuits (11) (21).
Output as VG. Both variable gain amplifier circuits (11) (21)
Operates at a predetermined gain until the gain control signal VG reaches a predetermined reference level. Then, when VG exceeds the reference level, both variable gain amplifier circuits (1
1) The gain of (21) becomes small.

FIG. 3 shows one of the signal processing circuits (12) and (22), for example, the right pickup coil (6
The characteristics when only the output VDR of the signal processing circuit (22) corresponding to R) is input to the amplifier circuit (14) are shown. A curve A shows the gain change characteristic of both variable gain amplifiers (11) and (21) with respect to the induced voltage of the right pickup coil (6R). Curve B is the right pickup coil (6R)
3 shows the output (speed command signal for the left drive motor (5L)) VDR of the signal processing circuit (22) with respect to the induced voltage VAR of. A curve C shows the output of the signal processing circuit (22) with respect to the induced voltage of the right pickup coil (6L) when the gain control is not performed.

When the induced voltage VAR of the pickup coil (6R) is less than a predetermined level VO, both variable gain amplifier circuits (11)
The gain of (21) is constant, and is 20 [dB] in this example. Therefore, when the induced voltage VAR of the coil (6R) is equal to or lower than the predetermined level VO, the speed command signal VDR becomes higher as the induced voltage VAR of the pickup coil (6R) becomes higher.

When the induced voltage VAR of the pickup coil (6R) exceeds a predetermined level VO, the gains of the variable gain amplifier circuits (11) (21) decrease as the induced voltage VAR increases. Therefore, the induced voltage VAR of the pickup coil (6R)
Exceeds the predetermined level VO, the speed command signal VDR
Becomes higher as the induced voltage VAR becomes higher, but the rate of change becomes much lower than that when the induced voltage VAR is at or below the predetermined level VO.

When the unmanned vehicle (1) is traveling on the straight part of the traveling route, the induced voltage VA of both pickup coils (6L) (6R)
L and VAR are almost equal and have values around the reference level VO.

In this state, if the unmanned vehicle (1) shifts to the left, the left pickup coil (6L) moves away from the induction wire (7), the induced voltage VAL becomes low, and the right pickup coil (6R) moves to the induction wire (7R). ), The induced voltage VAR increases. Left-side pickup coil (6C) induced voltage VAL
The right drive motor (5R) is controlled based on this, and the left drive motor (5L) is controlled based on the induced voltage VAR of the right pickup coil (6R). The speed becomes slower and the rotation speed of the left drive motor (5L) becomes faster. Therefore, the left shift of the unmanned vehicle (1) is corrected.

On the contrary, when the unmanned vehicle (1) shifts to the right, the induced voltage VAL of the left pickup coil (6L) increases and the induced voltage VAR of the right pickup coil (6R) decreases. Therefore, since the rotation speed of the left drive motor (5L) becomes slower and the rotation speed of the right drive motor (5R) becomes faster, the right shift of the unmanned vehicle (1) is corrected.

When the unmanned vehicle (1) travels on a curve point with a relatively small turning radius on the travel route, the induced voltage of the pickup coil inside the curve becomes very high, and the induction of the pickup coil outside the curve occurs. The voltage drops. For example, when traveling on a curve that turns right, the right (inner) pickup coil (6R) is connected to the guide wire (7).
The induced voltage becomes extremely high in the vicinity of, and the left (outer) pickup coil (6L) moves away from the induction wire (7), and the induced voltage becomes low.

In such a case, to turn the curve, it is necessary to increase the rotation ratio of the outer drive motor (5L) and the inner drive motor (5R), but the gain of the amplifiers (11) (21) remains constant. For example, one or both of the signal processing circuit (22) and the motor drive circuit (23) corresponding to the inner pickup coil (6R) are saturated. Also, the output of the signal processing circuit (12) corresponding to the outer pickup coil (6L) does not have a sufficiently low value, and the rotation speed of the inner drive motor (5R) does not sufficiently decrease. For this reason, the rotation speed of the outer drive motor (5L) does not become sufficiently higher than the rotation speed of the inner drive motor (5R), and the unmanned vehicle (1) cannot turn the curve and departs from the traveling route. However, in the above-mentioned unmanned vehicle (1), when the induced voltage of the inner pickup coil (6R) becomes extremely high during the right turn curve, the gains of the variable gain amplifiers (11) and (21) decrease. , Signal processing circuit (22) and motor drive circuit (23) corresponding to the inner pickup coil (6R)
Signal processing circuit (12)
Output is also low. For this reason, the rotation speed of the inner drive motor (5R) becomes sufficiently slower than the rotation speed of the outer drive motor (5L), so that a curve with a relatively small turning radius can be bent.

In the above embodiment, the gains of the amplifiers (11) and (21) are controlled based on the outputs of the signal processing circuits (12) and (22), but such control is not necessarily required.

The invention can also be applied to a light guide unmanned vehicle that travels along a light reflector laid on the ground. In this case, a light receiving element is used instead of the pickup coil of the above embodiment.

Effect of the Invention In the unmanned vehicle according to the present invention, the drive motor for the left drive wheel is controlled based on only the output signal of the right steering control detector among the output signals of the left and right steering control detectors, and the right drive The drive motor for the wheels is controlled based on only the output signal of the left steering control detector among the output signals of the left and right steering control detectors, so that the configuration of the traveling control circuit is very simple. .

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 is a block diagram showing an unmanned vehicle, FIG. 2 is an electric block diagram showing a traveling control circuit,
FIG. 3 is a graph showing the relationship between the gain of both variable gain amplifier circuits and the speed command signal with respect to the induced voltage of the pickup coil. (1) …… Unmanned vehicle, (4L) …… Left drive wheel, (4R) ……
Right drive wheel, (5L) …… left drive motor, (5R) …… right drive motor, (6L) …… left pickup coil,
(6R) …… Right pickup coil, (12) (22)…
… Signal processing circuit, (13) (23) …… Motor drive circuit.

Claims (2)

[Scope of utility model registration request] 1. A pair of left and right steering control detectors, which are provided symmetrically with respect to a center line of a vehicle body and generate a detection signal according to a distance between them and an interaction with a conductor laid on the ground. And an unmanned vehicle including a pair of left and right drive wheels that are symmetrically provided with respect to the center line of the vehicle body and are driven by separate drive motors, the drive motor for the left drive wheel is used for left and right steering control detection. Based on only the output signal of the steering control detector on the right side among the output signals of the control device, the rotation speed is controlled to decrease as the distance between the steering control detector on the right side and the guide increases. The drive motor for the vehicle is based on only the output signal of the left steering control detector among the output signals of the left and right steering control detectors, and as the distance between the left steering control detector and the inductor increases, Unmanned vehicle characterized by being controlled that as the rotational speed becomes late. 2. A first speed command signal generating circuit which includes a first variable gain amplifier circuit for amplifying a detection signal of a steering control detector on the left side and which outputs a speed command signal for a right drive motor, and a right steering wheel. A second speed command signal generating circuit that includes a second variable gain amplifier circuit that amplifies the detection signal of the control detector and that outputs a left drive motor speed command signal, and a speed that is the larger of the two speed command signals. When the command signal exceeds a predetermined level, gain control means is provided for lowering the gains of both variable gain amplifier circuits as the speed command signal becomes larger, and a utility model registration claim is provided. The unmanned vehicle according to item 1.