JPH0352082B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a traveling control method for a traveling bogie, particularly for an unmanned and automatically traveling bogie.

2. Description of the Related Art In automated warehouses, machine factories, and the like, trolleys that travel automatically under remote control are used as means for transporting goods.

Although such self-propelled carts do not have any major problems when traveling in a straight line, they do have problems especially when traveling on curved sections. That is, the bogie is forced to run unstable due to the centrifugal force at the curved portion, and in some cases, it may be necessary to issue a deceleration command to reduce the running speed. In other words, if the radius of the curved section is large, there is no need to reduce the speed, but if the radius becomes small, the centrifugal force may cause the cart to deviate from the track, or the cargo placed on the cart may collapse or fall. Therefore, if the radius is smaller than a certain radius determined in relation to the traveling speed of the bogie, the traveling speed must be reduced.

In this case, a deceleration signal is required before the curve, and an acceleration signal is required behind the curve. Therefore, two signal devices are installed for each curve, and in order to increase running efficiency, it is necessary to There is the trouble of having to externally set the speed to match the difference in the radius of the parts.

The present invention aims to solve the above problem, and it is possible to control the speed at the curved section without installing a signal at each curved section, and without giving an external command. The bogie is configured to control its own running speed by comparing the deviation amount of the induced voltage detected by the sensor with a predetermined reference value.

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

Figures 1 and 2 show an example of a self-propelled trolley. The frame body of the trolley is composed of frames 1, 2 and supports 3, 3, and two drive wheels 4, 5 and one or more wheels. It has a support ring 6. The above two driving wheels 4,
5 are each equipped with a DC motor and brake.
Furthermore, antennas 7 and 8, which will be described later, are provided at the front and rear of the truck, and signals are exchanged with a guide wire 9 buried in the running path.

Note that a positioning device 11 is provided on the lower surface of the trolley 10 to perform positioning with respect to the ground. That is, a conical body 12 is fixedly installed at a location on the ground where the bogie is to be positioned, and the bogie 10 is provided with four conical discs 13 corresponding to the conical bodies 12.

The conical disk 13 is fixed to a piston rod of a cylinder 14 fixedly installed vertically on the truck.

In addition, bumpers 15 are installed at the front and rear of the truck so as to be able to swing in a horizontal plane by deflecting the bumper 15 and stopping the truck when it comes into contact with an obstacle.

Guide rollers 17 and 18 on which the cargo 16 is placed are arranged on the upper surface of the cart.

In such a self-propelled trolley 10, while the antenna 7 or 8 searches for the magnetic field generated from the guide wire 9,
The vehicle travels along the guide line 9, travels along a straight path by rotating the two driving wheels at the same speed, and travels along a curved path by giving a speed difference to the two driving wheels. .

Figure 3 shows the antenna 7 installed on the front and rear of the bottom of the truck.
8, the antennas 7 and 8 have the same structure, and one antenna on the side in the traveling direction of the truck acts. That is, the transmitting antenna 19 has a coil 21 wound around a magnetic core 20 such as a ferrite core, and the receiving antennas 22a and 22b are arranged to the left and right with the center of the magnetic cores 23 and 24 made of ferrite, etc. similar to the above. Each antenna is wound with coils 25 and 26 having the same number of turns, and each antenna is housed in a plastic antenna box.

The receiving antennas 22a and 22b receive various signals such as detection of running induced current flowing in the guide line 9 of the running route, starting signals from the ground control device, and processing of cargo on the trolley.
is used to transmit a position confirmation signal or status signal of the bogie itself to the ground control device.

FIG. 4 is a block diagram showing an embodiment of a travel control device having such an antenna, in which a deviation amount detection circuit 27 detects the induced voltage from the antenna 7 or 8, and a signal is output according to the detected deviation amount. Signal amount detection and amplifier 28, 29 for detecting
and motors 31 and 3 whose rotational speed is adjusted by a signal from the amplifier.
2 and drive wheels 4, 5 driven by motors 31, 32, etc.

Furthermore, a tachometer generator 3 detects the rotation speed of the motors 31 and 32, that is, the rotation speed of the wheels 4 and 5.
A block circuit 35 inputs the signals detected from the motors 3 and 34, detects the speed and speed difference of both wheels, and instructs acceleration/deceleration. A second control section 37 is provided, which includes a block circuit 36 and the like that outputs a signal.

The first and second control sections 30 and 37 are configured as one microcomputer 38.

Note that the control section can also be configured to input the induced voltage of the antenna 7, the rotational speed of the wheels 4 and 5, etc. to one deviation detection circuit 27 as shown in FIG.

Therefore, when traveling in a straight line as shown in FIG.
It runs in the center between a and 22b. That is, the induced voltages of the left and right antennas 22a and 22b are checked at regular intervals, and if there is a difference between the voltages, the left and right drive motors are controlled by the difference to cause the truck to travel in a straight line.
Theoretically, there should be no voltage deviation between the left and right coils when driving in a straight line, but in reality there is always a slight deviation due to the influence of the road surface, misalignment of ground guidance lines, or control time delays. If this deviation is within a certain value, it will not affect the running of the bogie.

The above constant value is used as a reference value, and if the reference value is exceeded, it means that the bogie is running on a curve. In this case, a command is issued from the control unit to reduce the running speed of the bogie, and the induced per mileage is This increases the number of voltage checks and corrects deviations in a short time.

That is, when the trolley 10 turns to the left as shown in FIG. 6, the relationship between the antennas 22a, 22b and the guide wire 9 is as shown in FIG.
An induced voltage V1 larger than normal is generated in the antenna 22b, and an induced voltage V2 smaller than normal is generated in the antenna 22b, and the voltage difference V1-V2 becomes larger than a certain reference value V. Therefore, the deviation detection circuit 27 of FIG. A deceleration command is issued to the wheels 4 and 5, and the drive motors 31 and 32 are decelerated, and a difference in rotation speed for curved travel is given to the rotational speed of both wheels, and the traveling speed of the bogie is reduced to low-speed travel. At the same time, steering suitable for driving on curves is performed.

Note that the method for returning to the original speed after the end of curve travel is performed as follows. That is, as mentioned above, when a deviation of more than a certain V occurs between the two coils,
Although the speed is reduced and the deviation is smaller when traveling on a curve than when entering a curve, deviations above a certain level are caused by the bending of the guide line.

This value can be determined experimentally. That is, the deviation amount during curve travel can be set based on the travel speed, radius of curvature, etc.

Assuming that this value is v, if the voltage difference V1-V2 between both coils 25 and 26 becomes smaller than the set value v, it is assumed that the vehicle has escaped from the curved portion, and the traveling speed is returned to the original speed.

In the above embodiment, a two-wheel drive case has been described, but a one-wheel drive case is also possible. That is, in FIG. 8, a self-propelled truck 39 is provided with one driving wheel 40 and two driven wheels 41 and 42. The driving wheel 40 is rotated by a driving motor 43, and the chain is rotated by a steering motor 44. belt 45
The wheel 40 is configured to change its angle from side to side around a vertical axis 46, and the antenna 7 provided on the front lower surface of the truck 39 has the same structure as the above embodiment, and includes two receiving antennas 22a, 22b, and runs along the guide line 9.

Furthermore, the induced voltage from antenna 7 is
The voltage is input to the microcomputer 47 via the converter, and as in the above embodiment, the voltage deviation is detected and calculated. If the deviation amount is greater than or equal to the set value, a deceleration command is given to the drive motor 43 and the steering motor 44 is Give either a forward or reverse rotation command to the machine and start running on a curve.

As mentioned above, by installing a control device on the self-propelled bogie itself that detects the amount of deviation between the two induced voltages obtained from the antenna, performs predetermined calculations, and issues commands for acceleration and deceleration to the drive wheels, For example, the 9th
When driving on a curved road as shown in the figure,
(A) is a point in front of the entrance side of the curved section (between BC), and point (D) is a point at the rear of the exit side. Draw a traveling speed diagram of line L1. In other words, since point (A) is still on a straight line, when it enters a curved line without decelerating,
In other words, when passing point (B) slightly, the traveling speed will be reduced due to the detection of the voltage deviation amount of the antenna, and when slightly passing point (C), a speed increase command will be given and the original traveling speed will be restored. is accelerated to return to .

Therefore, the distance traveled at a deceleration speed slower than the normal speed when traveling in a straight line is S1.

On the other hand, when using other methods, i.e., giving some kind of acceleration/deceleration commands from the outside on the entrance and exit sides of a curved section, it is impossible to decelerate immediately before the curved section (B) and accelerate immediately after the curved section (C); The deceleration command must be given at point A) and the acceleration command must be given at point (D).Therefore, traveling on the curved section will be in the state shown by line L2 in Figure 10, and the deceleration traveling distance slower than normal will be in the range shown by S2, This is longer than in the case of the present invention, and it takes more time to travel on curved sections.

As described above, in the present invention, the amount of deviation of the induced voltage from the antenna having two receiving coils for detecting the guide wire laid on the floor of the self-propelled trolley is detected, and the drive wheel is applied based on the detected signal. By decelerating and controlling the speed of the bogie itself, it is possible to automatically control the rotation of the drive wheels in the curved part of the guide line without receiving commands from the outside, and to run at a deceleration speed. Since the amount of deviation of the induced voltage differs in relation to the radius of curvature of the curved section, the degree of curvature of the curve can be determined by increasing the number of times the deviation amount of the induced voltage is detected per traveling distance when traveling on a curve compared to when traveling in a straight line. Since the running speed can be set according to the speed, the trolley can run stably and efficiently on curved sections, making it extremely effective in transportation systems such as factories and warehouses. System availability can be increased.

[Brief explanation of drawings]

Fig. 1 is a schematic side view showing an example of a self-propelled cart, Fig. 2 is a front view of the same, Fig. 3 is a plan view of an antenna applied to the method of the present invention, and Fig. 4 is a schematic side view of an example of a self-propelled cart. FIG. 5 is a schematic configuration diagram showing an example of a mounted control device; FIG. 5 is a schematic configuration diagram showing another embodiment; FIG.
The figure is a plan view showing the relationship between the antenna and the guide wire in the curved part, Figure 8 is a schematic plan view of the configuration of a one-wheel drive self-propelled trolley, and Figure 9 is a diagram showing the relationship between the curved part and the signal application point. FIG. 10 is a diagram showing the running speed of the truck in a curved section. 4, 5, 40... Drive wheel, 9... Guide wire, 1
0, 39... Self-propelled trolley, 22a, 22b... Receiving antenna, 25, 26... Coil, 38, 47
...control section, V1-V2 ...deviation of induced voltage, V
...Reference value for straight route, v...Reference value for curved route.

Claims (1)

[Claims] 1. An antenna installed on the bogie searches for the magnetic field generated from the guide wire on the ground side, and in a self-propelled bogie that travels along the guide wire, an antenna with two receiving coils that detects the guide wire detects the magnetic field. The amount of deviation of the induced voltage is detected, and if the amount of deviation exceeds a reference value set on a straight path, the speed of the drive wheels is reduced based on the detection signal to cause the bogie to run at a low speed curve, and the above-mentioned If the amount of deviation is less than the reference value set for the curved route, the speed of the drive wheels is accelerated to make the bogie run in a high-speed straight line, and while the bogie is running on the curve, the induced voltage per traveling distance is reduced. A traveling control method for a self-propelled trolley, characterized in that the number of times the amount of deviation is detected is increased compared to when traveling in a straight line.