JPH0510687B2 - - 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 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. 3 is a block diagram of the above-mentioned unmanned vehicle which performs steering by giving a speed difference to the left and right drive wheels. In this figure, 1 is a speed command circuit, which outputs a 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 current magnetic field is laid along the driving route, and the route sensor 2 detects the alternating magnetic field, and when the vehicle deviates from directly above the steering guide line, the steering guide line generates a Outputs the deviation amount Δυ proportional to the deviation amount. This deviation amount Δυ is supplied to the adder circuit 3, and at the same time, is supplied to the adder circuit 5 via the inverting amplifier circuit 4 with a gain of -1. The addition circuit 3 adds the deviation amount Δυ to the reference speed υ, and supplies the addition result to the motor 6 via the speed control circuit C ₁ and the torque control circuit T ₁ . Motor 6 has speed control circuit C ₁ and torque control circuit T ₁
The drive wheels 7 on one side are driven under the control of the . Here, the speed control circuit _C1 consists of an amplifier circuit 8 and a tachometer generator 9, and the tachometer generator 9 is
The rotational speed of the drive wheel 7 is converted into a voltage signal and fed back to the amplifier circuit 8. Moreover, the torque control circuit _T1 has an amplifier circuit 10, and the motor 6
The drive current value of is set as the feedback value.

On the other hand, the addition circuit 5 outputs a deviation amount −Δυ from the reference speed υ.
is added, and the addition result is supplied to the motor 11 via the speed control circuit C ₂ and the torque control circuit T ₂ .
The motor 11 drives the drive wheel 12 on the other side under the control of the speed control circuit C ₂ and the torque control circuit T ₂ . Here, the speed control circuit C ₂ consists of an amplifier circuit 13 and a tachometer generator 14 , and the tachometer generator 14 converts the rotational speed of the drive wheel 12 into a voltage signal and feeds it back to the amplifier circuit 13 . Further, the torque control circuit _T2 has an amplifier circuit 15, and uses the drive current value of the motor 11 as a feedback value.

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 7 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.

[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, as described above, the tail wobbling phenomenon is likely to occur and the steering is unstable. In order to suppress this oscillation phenomenon, the amplifier circuits 10, 15
What is necessary is to reduce the gain of the motors 6 and 11 and reduce the torque generated by the motors 6 and 11. However, the motor 6,
By reducing the generated torque of 11, the steering becomes stable when driving on a straight route without obstacles, but if only one wheel runs over an uneven road surface and the resistance of one wheel increases,
Due to the lack of torque, there was a risk that the vehicle would not be able to return directly above the driving route and would go off route.

The present invention has been made in view of the above circumstances, and provides a driving control method for an unmanned vehicle that suppresses the oscillation phenomenon, stabilizes the steering, and prevents the vehicle from going off-route even when only one wheel runs onto an uneven road surface. The purpose is to

[Means for solving problems]

In order to achieve the above object, the first invention is characterized in that when the difference between the load torques of one and the other drive means is large, the reference speed output from the speed command circuit is made small.

Further, the second invention is characterized in that when the difference between the load torques of one drive means and the other drive means 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 amplifier circuits are increased when the difference between the load torques of one and the other driving means is large.

[Effect]

According to the first to third aspects of the invention, the responsiveness of the steering 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. 3 are designated by the same reference numerals. In this figure, reference numeral 20 denotes a torque difference detector, which determines the difference in drive current values between the motors 6 and 11, that is, the difference in load torque, and outputs it to the comparator 21. The comparator 21 compares the output of the torque difference detector 20 with a preset set value, and sets the output to zero when the output of the torque difference detector 20 is smaller than the set value, while 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. 3 described above, and when supplied with the steady signal S, reduces the reference speed υ to a small value. By lowering the reference speed υ, the average speed of the left and right drive wheels is reduced, the turning radius of the unmanned vehicle is shortened, and the responsiveness of the steering is increased.

The route sensor 23 corresponds to the route sensor 2 shown in FIG. 3 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. When the deviation amount Δυ becomes a large value, the speed difference between the left and right drive wheels becomes large, thereby increasing the responsiveness of the steering.

The amplification circuits 24 and 25 each have the above-mentioned third
This corresponds to the amplifier circuits 15 and 10 shown in the figure. Also,
The gains of these amplifier circuits 24 and 25 are variable,
When the steady signal S is not supplied from the comparator 21, the value is low, but when the steady signal S is supplied from the comparator 21, it increases.
As the gain increases, the speed difference between the left and right drive wheels increases, thereby increasing steering responsiveness.

In the above configuration, when the unmanned vehicle is traveling on a straight route without unevenness, the load torques applied to the left and right motors 6 and 11 are approximately equal, and the steady signal S is not output from the comparator 21. . Therefore, when the vehicle is traveling on the above-mentioned straight route, the gains of the amplifier circuits 24 and 25 are low, suppressing the oscillation phenomenon and stabilizing the steering. On the other hand, if only one side of the wheel runs over an uneven surface on the road, the running resistance on that side increases.
As the drive current of the motor 6 (or 11) increases, the unmanned vehicle deviates to the side where the running resistance increases. A difference occurs between the drive currents of the motors 6 and 11, and when the difference exceeds a predetermined value, a steady signal S is output from the comparator 21 and supplied to the speed command circuit 22, route sensor 23, and amplifier circuits 24 and 25. As a result, the reference speed υ decreases, the deviation amount Δυ increases, the gains of the amplifiers 24 and 25 increase, the responsiveness of the steering increases, and the vehicle quickly returns directly above the traveling route.

Furthermore, when the unmanned vehicle travels on a curved travel route (corner portion) as shown in FIG. Therefore, if the curvature R of the travel route at the corner is smaller than a predetermined value,
A steady signal S is output from the comparator 21.
This improves the responsiveness of the steering and allows the unmanned vehicle to sufficiently follow the travel route without going off-route even at a sharp corner with a short curvature R.

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 was set to increase or decrease in steps in response to the steady signal S, but the gain of the torque difference detector 2
It is also possible to receive an output of 0 directly and to continuously increase or decrease as the output increases.

Further, in this embodiment, the steady signal S is supplied to the speed command circuit 22, the route sensor 23, and the amplifier circuits 24, 25 at the same time. It may be supplied to at least one.

Furthermore, although the present embodiment has been described with respect to an unmanned vehicle that travels along a travel route, the invention does not depend on the travel route. It is clear that it can also be applied to self-driving unmanned vehicles.

[Effects of the Invention] As explained above, according to the first to third inventions, when traveling on a straight route without unevenness, the gains of the first and second feedback amplifier circuits can be reduced, and the oscillation phenomenon can be reduced. This makes it possible to stabilize the steering by suppressing the vibration, and improves the responsiveness of the steering and prevents the steering from going off route if only one wheel runs over an uneven surface.

Further, according to the present invention, the responsiveness of the steering is improved even when driving around a corner,
Even around sharp corners, you can drive without going off route.

[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 schematic diagram showing the state in which the unmanned vehicle runs around a corner, and FIG. 3 is a diagram showing the configuration of a conventional unmanned vehicle. The block diagram shown in FIG. 4 is a graph showing the relationship between the amount of deviation and the amount of deviation in the root sensor. 1, 22... Speed command circuit, 2, 23... Route sensor, 6, 11... Motor (driving means), 7,
12... Left and right drive wheels, 10, 25... Amplifying circuit (first feedback amplifying circuit), 14, 24... Amplifying circuit (second feedback amplifying circuit), C ₁ , C ₂ ... Speed control circuit .

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. a first rotation control circuit that controls the rotation of one of the drive means, a first feedback amplifier circuit that controls the torque of the one drive means, and a first rotation control circuit that controls the rotation of the one drive means based on the value obtained by subtracting the deviation amount from the reference speed. a second rotation control circuit that controls the rotation of the other drive means; and a second rotation control circuit that controls the torque of the other drive means.
and a feedback amplifier circuit, and the unmanned vehicle travels by individually driving the left and right drive wheels by the one and the other drive means, wherein the difference in load torque between the one and the other drive means is large. A driving control method for an unmanned vehicle, comprising: reducing a reference speed output from the speed command circuit. 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 rotation control circuit that controls the rotation; a first feedback amplifier circuit that controls the torque of the one driving means; and a first rotation control circuit that controls the rotation of the other driving means based on the value obtained by subtracting the deviation amount from the reference speed. a second rotation control circuit that controls the torque of the other driving means;
and a feedback amplifier circuit, and the unmanned vehicle travels by individually driving the left and right drive wheels by the one and the other drive means, wherein the difference in load torque between the one and the other drive means is large. A driving control method for an unmanned vehicle, comprising increasing a deviation amount output from the route sensor. 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 rotation control circuit that controls the rotation; a first feedback amplifier circuit that controls the torque of the one driving means; and a first rotation control circuit that controls the rotation of the other driving means based on the value obtained by subtracting the deviation amount from the reference speed. a second rotation control circuit that controls the torque of the other driving means;
and a feedback amplifier circuit, and the unmanned vehicle travels by individually driving the left and right drive wheels by the one and the other drive means, wherein the difference in load torque between the one and the other drive means is large. In this case, a method for controlling the running of an unmanned vehicle, characterized in that the gains of the first and second feedback amplifier circuits are increased.