JP2002199501A - Velocity detection control device of automated guided vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a velocity detection control device of an automated guided vehicle which is able to properly control a driving motor 4 even in the case that a rotary encoder 5 and an F/V conversion unit 8 are malfunctioning. SOLUTION: Two optical sensors 7a and 7b are used, velocity of the automated guided vehicle is calculated by each optical sensor 7a and 7b, the largest value of the velocity acquired by the calculation is set as the detected velocity value (V), and the driving motor 4 is controlled by a motor driver 3 in order to minimize the deviation between the detected velocity value (V) and a speed command 1. In case that any of the detected velocity value (V) of the automated guided vehicle measured by the two optical sensors 7a and 7b exceeds a preset range, a high-speed rotating dummy signal is set as the detected velocity value (V) by deciding that there is some kind of abnormality.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed detection control device for an automatic traveling vehicle.

[0002]

2. Description of the Related Art FIG. 3 is a schematic diagram of a speed detection control device for controlling a traveling speed and a traveling direction (forward or backward) of a conventionally used automatic traveling vehicle. This speed detection control device for an automatic traveling vehicle mainly includes a traveling motor 4, a rotary encoder 5, and a controller 11.

A rotary encoder 5 has a disk 6 having slits 16 at equal intervals around the rotation axis of the traveling motor 4.
Are mounted, and two optical sensors 7a and 7b each having a light emitting unit and a light receiving unit are arranged so as to sandwich the disk 6.

The rotation of the traveling motor 4 causes the wheels (not shown) of the self-propelled vehicle to rotate and the disk 6 to rotate. The number of pulses of light passing through the slit 16 per unit time from the light projecting unit per unit time by the light receiving units of the optical sensors 7a and 7b (that is, the frequency of the light pulse)
Is measured.

The two optical sensors 7a and 7b are arranged at positions where the phases of the respective pulses are shifted by about 90 degrees in order to detect the rotation direction of the traveling motor 4 at a normal traveling speed of the automatic traveling vehicle. Have been. And the optical sensor 7
The phases of the pulses (a-phase and b-phase) from a and b are measured by the rotation direction detector 9. Based on the phase difference between the two phases (a phase and b phase), the rotation direction of the traveling motor 4 is detected to determine the traveling direction of the automatic traveling vehicle, and this is output to the rotation direction polarity adding unit 10.

[0006] The one optical sensor 7a is provided with a slit 1
When the disk 6 containing 6 rotates, a pulse of light having a frequency proportional to the number of revolutions of the traveling motor 4 is measured, and the pulse is measured by F / V.
Output to the conversion unit 8. The F / V conversion unit 8 converts the voltage into a voltage corresponding to the frequency pulse, and outputs the voltage to the rotation direction polarity adding unit 10.

The rotation direction polarity adding section 10 receives information on the rotation direction of the traveling motor 4 from the rotation direction detection section 9 and the F / F
The information about the rotation frequency of the traveling motor 4 from the V conversion unit 8 is added to the output, and the result is output to the deviation signal determination unit 2.

The deviation signal determination unit 2 calculates a deviation between the speed command unit 1 and the signal from the rotation direction polarity adding unit 10 and operates the motor driver 3 so as to minimize the deviation. The number of rotations and the direction of rotation are controlled.
In general, as the speed command unit 1, a method that is programmed in advance according to the traveling path of the automatic traveling vehicle is used.

[0009]

However, when the above-described speed detection control device is used, the rotary encoder 5
Fault occurs and the pulse no longer occurs normally, or F
When a voltage corresponding to the rotation speed of the traveling motor 4 is not output due to a failure of the / V conversion unit 8, there are the following problems.

That is, in such a case, since a normal signal is not output from the rotation direction polarity adding section 10 to the deviation signal determining section 2, it may be impossible to properly grasp and control the rotational speed of the traveling motor 4 in some cases. Was done.

An object of the present invention is to solve the above-mentioned problems, and to provide an automatic traveling vehicle capable of appropriately controlling the traveling motor 4 even when the rotary encoder 5 or the F / V converter 8 fails. To provide a speed detection control device.

[0012]

According to a first aspect of the present invention, a speed of an automatic traveling vehicle is calculated by using a rotary encoder having an optical sensor to obtain a speed detection value. In the speed detection control device for an automatic traveling vehicle that controls the traveling motor via a motor driver so as to reduce the deviation between the speed command and the speed command, a plurality of optical sensors are used, and It is characterized in that the speed is calculated, and the largest value among the calculated speeds is set as the detected speed value.

In the second invention, if any of the speeds of the automatic traveling vehicle measured by the plurality of optical sensors is out of a predetermined range, it is determined that there is an abnormality, and the high speed rotation is determined. In the third aspect, the pseudo signal is set as a speed detection value. In the third invention, the traveling direction of the self-driving vehicle is determined based on the measured phase difference using two optical sensors. It is characterized by.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram of a speed detection control device of the present invention, and FIG. 2 is a flowchart showing a main part of the speed detection control device of the present invention.

1. 1. Hardware of the Present Invention As shown in FIG. 1, the speed detection control device for an automatic traveling vehicle includes a traveling motor 4, a rotary encoder 5, and a controller 11 as main components.

A rotary encoder 5 includes a disk 6 having slits 16 at equal intervals around the rotation axis of the traveling motor 4.
Are mounted, and two optical sensors 7a and 7b each having a light emitting unit and a light receiving unit are arranged so as to sandwich the disk 6.

The rotation of the traveling motor 4 causes the wheels (not shown) of the self-propelled vehicle to rotate and the disk 6 to rotate. Then, the number of light pulses passing through the slit 16 per unit time from the light projecting unit per unit time by the light receiving units of the optical sensors 7a and 7b (that is, the frequency of the light pulse)
Is measured.

The two optical sensors 7a and 7b are positioned at positions where the phases of the respective pulses are shifted by about 90 degrees in order to detect the rotation direction of the traveling motor 4 at a normal traveling speed of the automatic traveling vehicle. Are located. The phases of the pulses (a-phase and b-phase) from the optical sensors 7a and 7b are measured by the rotation direction detector 9. These two-phase pulses (a-phase and b-phase)
The traveling direction of the traveling vehicle (forward or backward) is determined by detecting the rotation direction of the traveling motor 4 based on the phase difference of the traveling motor 4 and is output to the rotation direction polarity adding section 10 and the high-speed rotation pseudo signal section 14.

The light receiving portions of the two optical sensors 7a and 7b are connected to the traveling motor 4 when the disk 6 having the slit 16 rotates.
, And outputs the pulses to the two F / V converters 8a and 8b, respectively. The F / V converters 8a and 8b convert the voltage into a voltage corresponding to a frequency pulse, and convert the voltage into a high value priority unit 12 and a pulse abnormality detection unit.
Output to 13 respectively.

If the voltage of the a-phase and the b-phase converted by the F / V converters 8a and 8b vary, the high-value priority unit 12 determines the higher value of the voltages as the speed detection value (V ) To output to the rotation direction polarity adding unit 10. That is, when it is determined that either the a-phase or the b-phase pulse is not output normally, the signal indicating that the traveling motor 4 is rotating at high speed is used with priority given to safety. I did it. When the pulses of the a-phase and the b-phase are equal, the pulse of the a-phase is prioritized.

The rotation direction polarity adding section 10 adds the information on the rotation direction of the traveling motor 4 from the rotation direction detecting section 9 and the information on the rotation frequency of the traveling motor 4 selected by the high value priority section 12 to provide feedback. The signal is output to the signal generator 15.

On the other hand, in the pulse abnormality detecting section 13, F /
If the voltage signal from the V converters 8a and 8b is out of the preset range, it is determined that some abnormality has occurred in the rotary encoder 5 or the F / V converters 8a and 8b. The information is output to the high-speed rotation pseudo signal section 14 and set.

In the high-speed rotation pseudo signal section 14, when the pulse abnormality detection section 13 determines that there is an abnormality, a predetermined high-speed rotation pseudo signal is added to the information on the rotation direction from the rotation direction detection section 9. And outputs it to the feedback signal generator 15. As the high-speed rotation pseudo signal, a signal indicating that the automatic traveling vehicle is currently traveling at the maximum speed is used.

When there is no output from the high-speed rotation pseudo signal section 14, the feedback signal generation section 15 selects the signal from the rotation direction polarity adding section 10 and outputs it to the deviation signal determination section 2. On the other hand, when there is an output from the high-speed rotation pseudo signal unit 14, the signal from the high-speed rotation pseudo signal unit 14 is preferentially selected and output to the deviation signal determination unit 2.

The deviation signal judging section 2 calculates a deviation between the speed command section 1 and the signal from the feedback signal generating section 15 and operates the motor driver 3 so as to minimize the deviation. Control the number and direction of rotation. In general, as the speed command unit 1, a method that is programmed in advance according to the traveling path of the automatic traveling vehicle is used.

2. Software of the Present Invention Next, the software relationship of the present invention will be described in more detail with reference to FIG. 1 described above and a flowchart showing a main part of the speed detection control device of the present invention shown in FIG. The speed detection control device of the present invention inputs a signal from the rotary encoder 5 to the controller 11 and performs arithmetic processing with various devices in the controller 11 and a microcomputer (not shown) (FIG. 1).

As described above, the rotation speed of the traveling motor 4 is converted into a pulse-like frequency signal by using the rotary encoder 5 and the frequency signal is sent to the F / V converters 8a and 8b of the controller 11. Input and convert to voltage.

In S1 in FIG. 2, the F / V converter 8a calculates the rotation speed of the traveling motor 4, that is, the speed detection value (Va) of the automatic traveling vehicle, from the frequency of the phase a and converts it into a voltage. Also in S2, the F / V converter 8b similarly detects the speed detection value (Vb) of the automatic traveling vehicle from the b-phase frequency.
Is calculated and converted into a voltage.

In S3, it is determined whether or not the speed detection values (Va, Vb) obtained by the calculation are within a preset range. The speed detection values (Va, Vb) are within a preset range (S3), and in S4, Va>
In the case of Vb, Va is set as the speed detection value (V) (S
5) If Va <Vb, Vb is set as the speed detection value (V) (S6).

That is, by setting the larger one of the detected speed values (Va, Vb) to the detected speed value (V) (S5, S6), the two optical sensors 7a, 7b of the rotary encoder 5 are set. In the case where one of the outputs fails and the output is lost or the F / V converters 8a and 8b fail,
It is possible to prevent the speed detection value (V) from becoming zero.

On the other hand, in S3, the speed detection value (V
If any of a, Vb) is not within the preset range, the pulse abnormality detection unit 13 determines in S9 that the state is abnormal. In S10, the high-speed rotation pseudo signal section 14 forcibly sets the high-speed rotation pseudo signal as the detected speed value (V). The high-speed rotation pseudo signal was set to the maximum speed of the autonomous vehicle.

In S7, a deviation between the speed command value from the speed command unit 1 and the detected speed value (V) is calculated, and the motor driver 3 is controlled so that the difference becomes small. Therefore, if the rotary encoder 5 or the F / V converters 8a, b fail and the speed detection values (Va, Vb) become zero or are not within the set range, the high-speed signal pseudo signal from S10 is output. Can be forcibly set as the speed detection value (V), so that the traveling motor 4 can be prevented from rotating at high speed.

[0033]

As described above, according to the present invention, even if the rotary encoder or the F / V converter fails, the traveling motor can be prevented from rotating at a high speed, which is excellent in terms of safety. It is a thing.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a speed detection control device of the present invention.

FIG. 2 is a flowchart showing a main part of the speed detection control device of the present invention.

FIG. 3 is a schematic diagram of a speed detection control device conventionally used.

[Explanation of symbols]

1: Speed command section 9: Rotation direction detection section 2: Deviation signal determination section 10: Rotation direction polarity addition section 3: Motor driver 11: Controller 4: Traveling motor 12: High value priority section 5: Rotary encoder 13: Pulse abnormality detection section 6: Disk 14: High-speed rotation pseudo signal section 7a-7b: Optical sensor 15: Feedback signal generation section 8, 8a, 8b: F / V conversion section 16: Slit

Claims (3)

[Claims] 1. A traveling motor via a motor driver for calculating a speed of an automatic traveling vehicle by using a rotary encoder having an optical sensor to obtain a speed detection value and reducing a deviation between the speed detection value and a speed command. In the automatic traveling vehicle speed detection control device, a plurality of optical sensors are used, the speed of the automatic traveling vehicle is calculated by each optical sensor, and the largest value among the calculated speeds is detected. A speed detection control device for an autonomous vehicle, which is set to a value. 2. If any one of the speeds of the automatic traveling vehicle measured by the plurality of optical sensors is out of a predetermined range, it is determined that there is an abnormality, and a high-speed rotation pseudo signal is output. 2. The speed detection control device for an automatic traveling vehicle according to claim 1, wherein the detection value is set to a detection value. 3. The speed detection control of an automatic traveling vehicle according to claim 1, wherein the traveling direction of the automatic traveling vehicle is determined based on the measured phase difference using two optical sensors. apparatus.