JPH0510686B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for controlling the running of unmanned vehicles used in factories, warehouses, etc.

[Prior art]

For unmanned vehicles, a speed difference is given to the left and right drive wheels,
There is something that does the steering. Although this steering method has advantages such as being able to spin turns, it has the disadvantage that it is more likely to cause so-called tail wobbling than a method that uses an independent steering wheel, and the steering is unstable. .

FIG. 2 is a block diagram of the above-mentioned unmanned vehicle that performs steering by giving a speed difference to the left and right drive wheels. In this figure, 1 is a speed command circuit,
Outputs the reference speed υ. Further, 2 is a route sensor that detects deviation from a predetermined running route and outputs a deviation amount Δυ. To explain further, a steering guide line that generates an alternating magnetic field is laid along the driving route, and a route sensor 2 is installed.
detects the alternating magnetic field, and when the vehicle deviates from directly above the steering guide line, it outputs a deviation amount Δυ proportional to the amount of deviation, as shown in FIG.
This deviation amount Δυ is supplied to the adder circuit 3, and simultaneously passes through the inverting amplifier circuit 4 with a gain of -1 to the adder circuit 5.
supplied to The adding circuit 3 adds the deviation amount Δυ to the reference speed υ, and supplies the addition result to the motor ₇ via the speed control circuit C1. Motor 7 is a speed control circuit
Drive the drive wheels 8 on one side under the control of C ₁ .
Here, the speed control circuit _C1 consists of an amplifier circuit 6 and a tachometer generator 9.
converts the rotational speed of the drive wheel 8 into a voltage signal,
Feedback is provided to the amplifier circuit 6. The addition circuit 5 adds the deviation amount -Δυ to the reference speed υ, and supplies the addition result to the motor ₁₁ via the speed control circuit C2. The motor 11 is under the control of the speed control circuit _C2 ,
The drive wheel 12 on the other side is driven. Here, the speed control circuit C ₂ consists of an amplifier circuit 10 and a tachometer generator 13 , and the tachometer generator 13 converts the rotational speed of the drive wheel 12 into a voltage signal and feeds it back to the amplifier circuit 10 .

In the above configuration, when the vehicle is traveling directly above the travel route, the output of the route sensor 2 is zero, and therefore both drive wheels 8 and 12 rotate at a constant speed. However, if the vehicle deviates from the travel route due to disturbances, running resistance, or a difference in wheel diameter due to wear, the route sensor 2 outputs a deviation amount Δυ, which causes a speed difference between the left and right drive wheels. is given and the vehicle is returned directly above the driving route. Further, at a corner portion of the travel route as shown in FIG. 4, the vehicle 14 travels on the curved travel route 15 in a manner that follows the curved travel route 15 under the above-described control.

[Problem that the invention seeks to solve]

By the way, the above-mentioned unmanned vehicle that steers by giving a speed difference to the left and right drive wheels inherently has the disadvantage that it is susceptible to the tail wobbling phenomenon and the steering is unstable, as described above. In order to suppress this oscillation phenomenon, the amplifier circuits 6, 10
By reducing the gain, the steering becomes stable when driving on a straight route, but when driving around a corner, the drive wheels 8 are driven at a higher speed than when driving straight. As a result, there is a risk of off-route (deviating from the wheel) due to insufficient steering gain.

In view of the above-mentioned circumstances, it is an object of the present invention to provide a driving control method for an unmanned vehicle that suppresses the oscillation phenomenon, stabilizes the steering, and prevents the vehicle from going off-route at corners.

[Means for solving problems]

In order to achieve the above object, the first invention is characterized in that when the difference between the rotational speeds of the left and right drive wheels is large, the reference speed output from the speed command circuit is reduced.

Moreover, the second invention is characterized in that when the difference in rotational speed between the left and right drive wheels is large, the amount of deviation output from the route sensor is increased.

Furthermore, the third invention is characterized in that the gains of the first and second feedback amplification circuits are increased when the difference in rotational speed between the left and right drive wheels is large.

[Effect]

According to the first to third aspects of the invention, followability at a corner portion is improved.

〔Example〕

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

FIG. 1 is a block diagram of an unmanned vehicle according to an embodiment of the present invention, and the same parts as in FIG.
The same symbols are attached. In this figure, 20 is a speed difference detector, and tachogenerators 9 and 13
The output difference is calculated and output to the comparator 21. The comparator 21 compares the output of the speed difference detector 20 with a preset set value, and when the output of the speed difference detector 20 is smaller than the set value, sets the output to zero, while reducing the speed difference Detector 20
When the output exceeds the set value, a steady signal S is supplied to the speed command circuit 22, route sensor 23, and amplifier circuits 24 and 25.

The speed command circuit 22 corresponds to the speed command circuit 1 shown in FIG. 2 described above, and when the steady signal S is supplied, the reference speed υ is reduced to a small value. Reference speed υ
By reducing this, the average speed of the left and right drive wheels is reduced, the turning radius of the unmanned vehicle is shortened, and the steering response is improved.

The route sensor 23 corresponds to the route sensor 2 shown in FIG. 2 described above, and when the steady signal S is supplied, the route sensor 23 increases the detection sensitivity of the traveling route and makes the deviation amount Δυ a large value. As the deviation amount Δυ becomes a large value, the speed difference between the left and right drive wheels increases,
This increases steering responsiveness.

The amplifier circuits 24 and 25 each have the second
This corresponds to the amplifier circuits 10 and 6 shown in the figure. Further, the gains of these amplifier circuits 24 and 25 are variable, and are low when the steady signal S is not supplied from the comparator 21, but increase when the steady signal S is supplied from the comparator 21. By increasing the gain, the speed difference between the left and right drive wheels increases, thereby increasing the responsiveness of the steering.

In the above configuration, when the vehicle is traveling in a straight line, the speed difference given to the left and right drive wheels is small, and the steady signal S is not output from the comparator 21. Therefore, the gains of the amplifier circuits 24 and 25 are small, the oscillation phenomenon is suppressed, and the steering becomes stable. On the other hand, when the unmanned vehicle enters a corner, the speed difference given to the left and right drive wheels increases, and as a result, the steady signal S is output from the comparator 21, the reference speed υ decreases, and the deviation amount Δυ increases. and the gains of the amplifier circuits 24 and 25 are increased, and the responsiveness of the steering is increased.
Unmanned vehicles will be able to follow curved driving routes around corners.

Note that the reference speed υ of the speed command circuit 22, the deviation amount Δυ of the route sensor 23, and the amplifier circuits 24, 2
The gain of 5 increases or decreases stepwise in response to the steady signal S, but the gain of the speed difference detector 20
It is also possible to receive the output directly and to continuously increase or decrease as the output increases.

Further, in this embodiment, the steady signal S is supplied to all of the speed command circuit 22, route sensor 23, and amplifier circuits 24, 25 simultaneously, but at least one of the speed command circuit 22, route sensor 23, or amplifier circuits 24, 25 It may also be supplied to one source.

Furthermore, although this embodiment has been described with respect to an unmanned vehicle that travels along a travel route, it is clear that the present invention can also be applied to autonomous vehicles that are independent of the travel route.

〔Effect of the invention〕

As explained above, according to the first to third inventions, it is possible to reduce the gains of the first and second feedback amplifier circuits when traveling in a straight line, suppress the tail wobbling phenomenon, and stabilize the steering. At corners, the ability to follow the driving route is improved and there is no off-route deviation.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an unmanned vehicle according to an embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of a conventional unmanned vehicle, and FIG. 3 is a block diagram showing the configuration of a conventional unmanned vehicle. Graph showing relationships, 4th
The figure is a schematic diagram showing a state in which the vehicle 14 runs around a corner. 1, 22... Speed command circuit, 2, 23... Route sensor, 6, 25... Amplifier circuit (first feedback amplifier circuit), 10, 24... Amplifier circuit (second feedback amplifier circuit), 8 , 12... Left and right drive wheels.

Claims (1)

[Claims] 1. A speed command circuit that outputs a reference speed, a route sensor that detects a deviation in the vehicle position and outputs a speed deviation amount, and a speed control circuit that is based on a value obtained by adding the deviation amount to the reference speed. and a second feedback amplifier circuit that controls the rotation of the other drive means based on a value obtained by subtracting the deviation amount from the reference speed. In an unmanned vehicle that travels by driving the left and right drive wheels individually by the one and the other drive means, when there is a large difference in rotational speed between the left and right drive wheels, the speed command circuit outputs an output. A driving control method for an unmanned vehicle, the method comprising: reducing a reference speed. 2. A speed command circuit that outputs a reference speed, a route sensor that detects a deviation in the vehicle position and outputs a speed deviation amount, and a speed command circuit that outputs a speed deviation amount based on the reference speed plus the deviation amount. a first feedback amplifier circuit that controls rotation; and a second feedback amplifier circuit that controls rotation of the other drive means based on a value obtained by subtracting the deviation amount from the reference speed; In an unmanned vehicle that travels by driving the left and right drive wheels individually by the other drive means, when the difference in rotational speed between the left and right drive wheels is large, the amount of deviation output from the route sensor is increased. A driving control method for an unmanned vehicle characterized by the following. 3. A speed command circuit that outputs a reference speed, a route sensor that detects a deviation in the vehicle position and outputs a speed deviation amount, and a speed command circuit that outputs a speed deviation amount by detecting the deviation of the vehicle position, and a a first feedback amplifier circuit that controls rotation; and a second feedback amplifier circuit that controls rotation of the other drive means based on a value obtained by subtracting the deviation amount from the reference speed; In an unmanned vehicle that travels by driving left and right drive wheels individually by the other drive means, when the difference in rotational speed between the left and right drive wheels is large, the gains of the first and second feedback amplification circuits are increased. A driving control method for an unmanned vehicle characterized by increasing the speed.