JP2830722B2 - Unmanned traveling vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an unmanned traveling vehicle guided by a guide band provided on a floor along a traveling track and traveling unmanned, and more particularly to an unmanned traveling vehicle which can be constructed at a low cost.

[0002]

2. Description of the Related Art Conventionally, various types of unmanned vehicles used for transportation in factories have been developed and proposed.

[0003] A typical example of the traveling system is a type in which a guide belt provided along a traveling track is detected by a guide sensor and guided by the guide band to automatically travel.

[0004] Conventionally, typical unmanned vehicles of this type include a servo motor as a driving motor for left and right driving wheels,
In addition, a microcomputer is used as a controller for the control, and the actual rotation speed of the wheels is determined by a TG (tach generator)
And the like, which is detected by an external rotation detector and fed back, and a servomotor for driving the wheels is controlled so that the rotation speed of the wheels becomes the required rotation speed.

In the case of an unmanned traveling vehicle of this type, the transmission of commands by the microcomputer is fast, and since the servomotor is excellent in high-speed response, the traveling performance of the traveling vehicle with respect to the guidance band is good. Since the trajectory of the traveling vehicle is corrected while detecting the speed, there is an advantage that accurate control is possible.

[0006]

However, in the case of this unmanned traveling vehicle, the microcomputer as a controller and the servomotor are expensive (for example, the price of the servomotor per drive wheel is 400,000 yen) and the rotational speed of the wheel is detected. Therefore, there is a problem that an external rotation detector such as a tachogenerator must be mounted, and a space for the mounting is required.

[0007]

SUMMARY OF THE INVENTION The unmanned vehicle of the present invention has been devised to solve such a problem.
The gist of the invention is that (a) a guide band provided on the floor along a traveling track to guide the traveling vehicle is detected, and when a deviation of the direction of the traveling vehicle with respect to the guidance band occurs, this is output as a deviation signal. And (B) a left driving wheel D for driving the left driving wheel and the right driving wheel independently of each other.
C motor and DC motor for right driving wheel, and (c) those D
A driver circuit for the C motor and (d) a command signal of a drive voltage for the left drive wheel DC motor and the right drive wheel DC motor are output, and the traveling vehicle is deviated from the guidance zone. And a sequencer for outputting a preset command signal based on a deviation information signal issued from the guide sensor when the guide sensor detects that a voltage has actually been applied to each of the DC motors. And a driver circuit that supplies a voltage to the DC motor such that a voltage detected by the voltage sensor matches a drive voltage commanded by the sequencer. Is provided with a correction function for correcting

[0008]

In the unmanned traveling vehicle of the present invention, the traveling vehicle is guided by the guidance zone based on the detection of the guidance zone by the guide sensor and runs unmanned. Thus, when a deviation of the direction of the traveling vehicle occurs, this is detected by the guide sensor,
Output as a signal. The sequencer outputs a preset drive voltage command value for the DC motor as a signal based on the deviation information signal from the guide sensor.

An analog drive voltage having a magnitude corresponding to the command signal is supplied to each DC motor through a driver circuit, whereby each DC motor is driven according to the magnitude of the drive voltage, and the direction of the traveling vehicle is changed. Will be corrected.

[0010] Incidentally, the voltage of each DC motor fluctuates according to the load state or the like. Therefore, the drive voltage supplied to each DC motor may not always match the voltage actually applied to each DC motor. For example, when a load is applied to the DC motor, the voltage decreases, and the rotation speed decreases. Thus, if the traveling vehicle travels with such inconsistency, it will deviate from the predetermined track.

Therefore, in the present invention, a voltage actually applied to each DC motor is detected by a high impedance type voltage sensor, and the detected voltage value is a driving voltage value supplied to be applied to the DC motor, that is, Correction was performed so as to match the drive voltage value instructed by the signal from the sequencer, and the correction was applied to each DC motor.

When an unmanned traveling vehicle is constructed in accordance with the present invention, even if a DC motor having low response is used as the motor, the traveling vehicle can be guided well along the predetermined track to the guide zone, and can be satisfactorily performed. Running has been confirmed.

According to the present invention, the rotational speed of the wheels, which is conventionally considered necessary for the traveling control of the traveling vehicle, is not detected, and instead, the voltage actually applied to the drive motor is detected. It is characterized by the following.

According to the present invention, an inexpensive DC motor is used as a drive motor, and a low-cost sequencer is used as a controller, especially in the case of small-volume production. Because an external rotation detector such as a tachometer is not used, the cost of the entire traveling vehicle can be reduced, and there is no need to mount an external rotation detector such as a tachogenerator, so the installation space Can be saved, and the control device of the traveling vehicle can be simplified.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; 2 and 3, reference numeral 10 denotes a main body of the unmanned traveling vehicle. These drive wheels 12 have DC as a drive motor.
A motor 14 is operatively connected via a transmission mechanism 19 including a pulley 16 and a timing belt 18. still,
Each DC motor 14 is mounted on the main body 10 by a mounting plate 20.

At the front and rear ends of the traveling vehicle, rotatable free wheels 22 are provided. These universal wheels 22 are attached to the main body 10 via a link 26 and a bracket 28 that can rotate around a support shaft 24. Further, a shock absorber 30 for absorbing a shock is interposed between the bracket 28 and the main body 10.

Guide sensors (magnetic sensors) 32 are arranged at the front end position and the rear end position of the traveling vehicle. The guide sensor 32 at the front end position serves as a guide band (magnetic tape) 34 laid on the floor along the traveling track when the traveling vehicle moves forward.
The guide sensor 32 at the rear end position detects the guide band 34 when the vehicle retreats and guides the traveling vehicle. More specifically, as a magnetic sensor of the guide sensor 32, a 16-channel multi-switch including 16 circuits of high-sensitivity magnetic proximity switches is used, and a magnetic tape used as the guiding band 34 has a width of 3 cm corresponding to the 16-channel multi-switch. Things are used.

The DC motor 14 as the drive motor and the guide sensor 32 are electrically connected to a control unit 36. FIG. 1 systematically shows the circuit configuration of the control unit 36. In FIG. 1, reference numeral 38 denotes a sequencer as a controller to which signals from the front end guide sensor 32 and the rear end guide sensor 32 are input.

Reference numeral 40 denotes a switching means.
Is a signal from the front end guide sensor 32 when the traveling vehicle moves forward, and a rear end guide sensor 32
Is alternatively supplied to the sequencer 38.

The sequencer 38 also has an obstacle sensor 41 composed of a reflective photoelectric sensor and an address sensor 43 for detecting an address set along the traveling trajectory of the traveling vehicle.
Are connected, and the signal from each is
8 is input. Reference numeral 44 denotes an input unit for setting various numerical values and the like for the sequencer 38.

DC motor 14 as the drive motor
Are connected to the sequencer 38 via a driver circuit 42 and a D / A converter 45. Here, the driver circuit 42 sets the drive voltage commanded by the sequencer 38 to D
It is supplied to the C motor 14 and driven.

In this example, the voltage actually applied to the DC motor 14 is detected by a high impedance type voltage sensor 46, and a signal from the voltage sensor 46 is input to the driver circuit 42. . The driver circuit 42 performs a correction operation based on this signal, and acts so that the voltage applied to the DC motor 14 matches the commanded drive voltage.

Reference numeral 48 denotes an output terminal to which various devices such as a power stop relay 50 are connected. Here, the power stop relay 50 stops power supply when the running vehicle gets out of the running track for some reason or the like.

The sequencer 38 outputs a command value of a drive voltage for driving the DC motor 14 as a digital signal (in this example, output in 8 bits).
The guide sensor 32 transmits a shift information signal when the direction shifts, and the sequencer 38 generates a command value based on this signal, which is empirically determined and set in advance in accordance with the shift amount. Is output as a digital quantity.
Here, the information signal is switch on / off pattern information of each proximity switch constituting the magnetic sensor.

This output signal is converted into an analog voltage (± 10 V) by a D / A converter 45 and then input to a driver circuit 42 of each DC motor 14. DC motor 1
4 is basically driven by a drive voltage (± 24 V) of a value specified by the analog voltage.

As described above, in the traveling vehicle of the present embodiment, information on the deviation of the traveling direction is transmitted from the guide sensor 32 to the sequencer 38, and the sequencer 38 outputs a command signal corresponding to the deviation and outputs a DC motor signal. 14 is driven with an appropriate drive voltage.

At this time, when the voltage actually applied to the DC motor 14 is different from the commanded drive voltage,
This is corrected by the driver circuit 42, and an appropriate drive voltage is reliably applied to the DC motor 14.

As a result, the traveling vehicle surely travels smoothly along a predetermined track without detecting the rotation speed of the wheels and feeding it back and performing traveling control. In addition, the rotatable free wheel 22 at the front end and the rear end of the traveling vehicle is connected to the main body 10 via a link 26.
However, the present invention is not limited to this. For example, the link 26 may be removed, and the main body 10 and the universal ring 22 may be supported by providing guide means capable of moving vertically.

Although the embodiment of the present invention has been described in detail, this is merely an example, and the present invention can be configured in variously modified forms without departing from the gist thereof.

[Brief description of the drawings]

FIG. 1 is a diagram systematically showing a circuit configuration in a control device for an unmanned traveling vehicle according to an embodiment of the present invention.

FIG. 2 is a diagram showing the unmanned traveling vehicle from the back side.

FIG. 3 is a side view of the same unmanned traveling vehicle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Main body 12 Drive wheel 14 DC motor 19 Transmission mechanism 22 Free wheel 32 Guide sensor 34 Induction band 38 Sequencer 42 Driver circuit 45 D / A converter 46 Voltage sensor

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G05D 1/02 B60L 15/20

Claims (1)

(57) [Claims] (1) A guide band provided on a floor along a traveling track to guide a traveling vehicle is detected, and when a deviation of the direction of the traveling vehicle with respect to the guidance band occurs, this is used as a deviation signal. A guide sensor for outputting, (b) a left drive wheel DC motor and a right drive wheel DC motor for independently driving the left drive wheel and the right drive wheel, (c) driver circuits for the DC motors, and (d) When outputting a drive voltage command signal to the left drive wheel DC motor and the right drive wheel DC motor, and when the guide sensor detects that the traveling vehicle has shifted the direction with respect to the guidance band, And (e) detecting a voltage actually applied to each of the DC motor and a sequencer for outputting a preset command signal based on a deviation information signal issued from the guide sensor. And a driver circuit that corrects a supply voltage to the DC motor so that a voltage detected by the voltage sensor matches a drive voltage commanded by the sequencer. An unmanned vehicle having a correction function.