JPS63268009A - Unmanned guided vehicle - Google Patents

Abstract

PURPOSE:To enable an unmanned guided vehicle to run with a fixed distance secured from a wall by controlling a steering driver so that the distance between the vehicle and a prescribed distance is set at zero. CONSTITUTION:An ultrasonic distance sensor 7 of an unmanned guided vehicle 1 contains an ultrasonic wave carrier element, an ultrasonic wave receiver element and a control part and outputs the voltage corresponding to the distance lfrom a wall W to a steering control circuit 9. The control 9 compares the output voltage received from the sensor 7 with the reference voltage and outputs the positive or negative voltage to a motor driving circuit 8. The circuit 8 drives the motors 5 and 6 corresponding to the drive wheels 3 and 4 set at both sides of the back of the vehicle 1 with the difference secured between the rotational frequencies of both motors. Thus the circuit 8 performs the control to change the direction of the vehicle 1. Thus it is possible to drive the vehicle 1 automatically along the wall W with a fixed distance secured from the wall without using a guide line nor an optical reflecting belt.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an unmanned guided vehicle.

Problem of the Invention If it is possible to run an unmanned guided vehicle along a wall that exists on the ground or on the floor, there is no need to install guiding wires, light reflective strips, etc. that are conventionally required to guide an unmanned guided vehicle. It is very convenient as it can be done easily.

An object of the present invention is to provide an unmanned guided vehicle that can run along a wall at a certain distance from the wall.

Means for Achieving the Object The unmanned guided vehicle according to the present invention includes a steering drive device, a non-contact distance sensor for detecting the distance from the wall, and a detection distance of the distance sensor and a predetermined distance. The present invention is characterized by comprising a control device that controls the steering drive device so that the difference between the two becomes zero.

Embodiment FIG. 1 shows an unmanned guided vehicle. This unmanned guided vehicle (
1) is configured to run along a wall (W) existing in the running area at a predetermined distance from the wall (W).

A guide wheel (2) is provided at the center of the front width of the guide vehicle (1). Separate electric motors (
5) A pair of left and right drive wheels (3) and (4) respectively driven by (8) are provided. This guided vehicle (1
), the direction of the vehicle body can be changed by creating a difference in the rotational speed of both driving wheels (3) and (4).

A non-contact distance sensor (7), in this example an ultrasonic distance sensor, is attached to the front of the vehicle body for measuring the distance l from the wall (W). Furthermore, the guided vehicle (1) has
Motor drive circuit (8) and travel and steering control circuit (9)
) A guided vehicle control device (10) is installed.

Figure 2 shows the distance sensor (7) and the travel and steering control circuit (9).

The distance sensor (7) includes an ultrasonic wave transmitting element (11), an ultrasonic wave receiving element (12), and a control section (13) including a wave transmitting element driving circuit and a receiving signal processing circuit. There is. As shown in FIG. 3, the distance sensor (7) outputs a voltage signal E1 proportional to the distance I from the sensor (7) to the wall (W).

The reference level of the output voltage E1 of the sensor (7) is adjusted by a reference level adjustment circuit (22) including a semi-fixed resistance for reference level adjustment (21).

That is, the voltage E1 is converted to the voltage E2 which becomes zero level when the distance I between the sensor (7) and the wall (W) is a desired distance (hereinafter referred to as set distance) L, for example, 3 m. This voltage E2 is amplified by a non-inverting amplifier circuit (24) including an operational amplifier (23). Therefore, the output voltage E3 of the amplifier circuit (24) becomes zero when the interval l is equal to the set distance, and when the interval I is greater than the set distance, it becomes a positive value according to the deviation, and the interval ρ becomes equal to the set distance. When the deviation is smaller than the deviation, the value becomes a negative value corresponding to the deviation.

The output voltage E3 of the amplifier circuit (24) is sent to a voltage divider circuit consisting of a semi-fixed resistor (25) for adjusting swing sensitivity, and an inverting amplifier circuit (with an amplification factor of 1) including an operational amplifier (2B).
27) is also sent.

The voltage E3 sent to the voltage dividing circuit (25) is applied to the voltage dividing port W (
25) and then sent to the right drive wheel differential amplifier circuit (29) including an operational amplifier (28). A voltage divider circuit (25) is connected to the non-inverting input terminal of the operational amplifier (28).
> output voltage E4 is input, and a setting voltage E5 from a speed setting circuit consisting of a semi-fixed resistor (30) for standard speed adjustment is input to its inverting input terminal. The set voltage E5 is a negative voltage (-VO), and the output voltage ER of the differential amplifier circuit (29) is +VO (hereinafter referred to as reference speed voltage) [V] when the voltage E4 is zero, and the voltage E4 is positive. When , the value is larger than the reference speed voltage VO by the voltage corresponding to the voltage E4, and when the voltage E4 is negative, the reference speed voltage V
The value is smaller than O by a voltage corresponding to voltage E. In other words,
When the interval l is equal to the set distance, the voltage ER becomes the reference speed voltage VO, and when the interval I is greater than the set distance, the voltage ER becomes a value larger than the reference speed voltage VO by a voltage corresponding to the deviation, and the interval I becomes the set distance. When it is smaller than the reference speed voltage VO, it becomes a value smaller than the reference speed voltage VO by a voltage corresponding to the deviation.

The voltage E3 sent to the inverting amplifier circuit (27) is inverted by the inverting amplifier circuit (27). Therefore, the output voltage E6 (--E3) of the inverting amplifier circuit (27) becomes zero when the interval I is equal to the set distance, and when the interval l is equal to the setting button iW.
When it is larger than L, it takes a negative value according to the deviation, and when the interval I is smaller than the set distance, it takes a positive value according to the deviation.

The voltage E6 is sent to a voltage dividing circuit consisting of a semi-fixed resistor (31) for adjusting turning sensitivity, and is divided into voltages. This divided voltage E7 is sent to a left drive wheel differential amplifier circuit (33) including an operational amplifier (32). The output voltage E7 of the voltage divider circuit (31) is input to the non-inverting input terminal of the operational amplifier (32), and the semi-fixed resistor for standard speed adjustment (
A setting voltage E8 from a speed setting circuit consisting of 34) is input.

The set voltage E8 is a negative voltage (-VO) equal to the voltage E5, and the output voltage EL of the differential amplifier circuit (33) is equal to the voltage E7.
When is zero, it becomes +VO (reference speed voltage) [V],
When voltage E7 is positive, voltage E is lower than reference speed voltage VO.
When the voltage E7 is negative, the value becomes smaller than the reference speed voltage VO by a voltage corresponding to the voltage E7. In other words, when the interval I is equal to the set distance, the voltage ER becomes the reference speed voltage VO, and the interval I
When is larger than the set distance, contrary to the voltage ER,
The value is smaller than the reference speed voltage VO by the voltage corresponding to the deviation, and when the interval I is smaller than the set distance, the voltage ER
On the contrary, the voltage value corresponding to the deviation becomes larger than the reference voltage vO.

The output voltage ER of the differential amplifier circuit (29) for the right drive wheel is:
The output voltage E of the differential amplifier circuit (33) for the left drive wheel is sent to the drive circuit (8) as a motor control signal for the right drive wheel.
L is a drive circuit (8) as a motor control signal for the left drive wheel.
) will be sent to. The drive circuit (8) connects each motor (5) (
Each drive motor (5)<8) is drive-controlled so that the rotational speed of G) is a speed according to the corresponding motor control signal.

Therefore, when the interval I is equal to the set distance, the driving wheels (3) and (4) on both sides are rotated at a speed corresponding to the reference speed voltage VO. When the interval l becomes larger than the set distance, that is, when the guide vehicle (1) shifts to the right from the traveling path parallel to the wall (W) determined by the set distance,
The rotation speed of the right drive wheel (4) increases and the rotation speed of the left drive wheel (3) decreases, causing the guide vehicle (1) to turn to the left and correct the deviation. Conversely, when the interval I becomes smaller than the set distance, that is, when the guide vehicle (1) passes to the left of the travel route, the rotation speed of the right drive wheel (4) decreases and the rotation speed of the left drive wheel (3) decreases. The rotational speed of the guide vehicle (1) increases, the guide vehicle (1) is turned to the right, and the deviation is corrected.

As a result, the guide vehicle (1) automatically travels along the travel route.

In the above embodiment, the case where the wall (W) is on the left side of the unmanned guided vehicle (1) has been explained, but the unmanned guided vehicle (1)
If it is on the right side of the wall (W), the output voltage ER is used as the left drive wheel motor control signal, and the output voltage EL is
may be used as the right drive wheel motor control signal. Furthermore, if the control circuit (9) controls the drive motors (3) and (4) so that the difference between the detected distance I of the sensor (7) and the set distance becomes zero, then ” - Circuits other than those described above can be used. In addition to the ultrasonic type, a photoelectric type can be used as the distance sensor.

Furthermore, in the above embodiment, separate electric motors (5) (6)
This invention is applied to an unmanned guided vehicle (1) that is equipped with a pair of left and right drive wheels (3) (4) driven by Although the case has been described, the present invention can also be applied to an unmanned guided vehicle equipped with steered wheels that are directed by a direction motor. In this case, the direction motor may be controlled so that the difference between the detected distance I of the sensor (7) and the set distance becomes zero.

Effects of the Invention The unmanned guided vehicle according to the present invention includes a steering drive device, a non-contact distance sensor for detecting the distance from a wall, and a distance sensor in which the difference between the detection distance of the distance sensor and a predetermined distance is zero. Since the system is equipped with a control device that controls the steering drive device so that It is possible to run on a regular basis.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a configuration diagram showing an unmanned guided vehicle, FIG. 2 is an electric circuit diagram showing a travel and steering control circuit, and FIG. 3 shows an output voltage of an ultrasonic sensor. It is a graph showing the relationship between the distance from the sensor to the wall. (1)...Unmanned guided vehicle, (2) (4)...Drive wheel, (5) (6)...Electric motor, (7)...Distance sensor, (8)...Motor Drive circuit, (9)...Steering control circuit, (W)...Wall. Voltage E to above

Claims (1)

[Claims] A steering drive device, a non-contact distance sensor for detecting the distance from a wall, and a control that controls the steering drive device so that the difference between the detected distance of the distance sensor and a predetermined distance becomes zero. An unmanned guided vehicle equipped with equipment.