JPH0421124Y2 - - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention relates to a steering control device for an unmanned vehicle in an unmanned transportation system.

B. Summary of the invention The present invention detects when an unmanned vehicle is located near an intersection of the taxiways in an unmanned vehicle that controls the steering angle by detecting the magnetic field strength on the left and right sides of the taxiway through which current is passed using a pair of pickups. This eliminates unstable running at intersections by limiting the amount of steering while the vehicle is moving near the intersection.

C. PRIOR TECHNOLOGY In an unmanned transportation system, a pre-programmed or set travel course and route can be changed by steering an unmanned vehicle along a track or a taxiway installed on the ground side, and the travel position and loading position can be changed. The acceleration/deceleration range and stopping position are changed by drive control according to the loaded weight, and the system is used for unmanned operation control for cargo handling and various controls.

Here, in the taxiway method, as shown in Fig. 2, an alternating current or direct current of a constant frequency is passed through the guide wires L buried vertically and horizontally on the ground side, and the unmanned vehicle M detects the magnetic field induced by this current. Then, the steering control along the guideway L is performed. This unmanned vehicle M has a pair of pick-ups on the left and right in the direction perpendicular to the taxiway L, and the output of both pick-ups is controlled by controlling the steering wheels in the left and right directions according to the output deviation of both pick-ups. The deviation is zero, that is, the guideway is located at the center of the vehicle body, so that the vehicle can travel along the guideway L.

D Problems to be solved by the invention In the conventional steering control system, as shown in Figure 3, at the intersection of the taxiways, the interaction between the magnetic field generated by the guiding line _L1 (indicated by ) and the magnetic field generated by the guiding line _L2 occurs. This results in a distribution in which the strength of the magnetic field deviates from the center of the guiding wire. Therefore, the magnetic field detection by the left and right pickups P _L and _PR , that is, the steering angle control of the unmanned vehicle M deviates from the guide line, causing the unmanned vehicle M to wander from side to side as shown by the arrows. Such erratic running has the problem of cargo collapse and derailment, and the train is forced to slow down at intersections, reducing cargo handling efficiency.

E Means and effects for solving the problems The present invention was made in view of the above problems, and includes an intersection detection means for detecting that the guide line is located near an intersection, and a detection signal from this detection means. The control system is provided with a means for limiting the amount of steering when a given amount of steering is applied, and while the vehicle is traveling through an intersection, the responsiveness of the control system to the strength of the magnetic field is reduced, and the vehicle passes through the intersection by traveling in a straight line approximately in the direction in which the vehicle approaches the intersection.

F. Embodiment FIG. 1 is a circuit diagram showing an embodiment of the present invention. A pair of pick-ups P _R and _PL are provided on the left and right sides perpendicular to the front-rear direction of the unmanned vehicle, as in the past, and detect the magnetic field strength generated in the guide line L, respectively. Pickup P _R. The respective detection signals of P _L are applied to common inputs of high gain amplifiers R _H , L _H and low gain amplifiers R _L , _LL respectively. These amplifiers are constituted by operational amplifiers and the like, as shown by R _H and _RL . Both outputs of amplifiers R _H and R _L are input to one input of differential amplifier DA via analog switches AS _RH and AS _RL , and both outputs of amplifiers L _H and L _L are input via analog switches AS _LH and AS _LL . differential amplifier
Used as the other input of DA. The output of the differential amplifier DA is used as a steering angle set value or control signal for the steering angle control system.

Each analog switch is controlled to be on in a complementary manner to the right and left systems of the on/off output of the intersection detector CPS. The intersection detector CPS is an intersection signal generator installed just before the intersection (shown in Figure 2).
By detecting CPL, it is detected that the vehicle is located near an intersection. This detector CPS and signal generator CPL
is realized, for example, by using a CPL as an infrared light generator and a CPS as an infrared light detector, but other optical types, electromagnetic types, mechanical types, etc. can be designed as appropriate.

The output of the intersection detector CPS is an analog switch.
The logic inverter INV that turns on AS _RL and AS _LL and obtains its inverted signal is an analog switch AS _RH ,
Turn on AS _LH .

In this configuration, while the unmanned vehicle is traveling on the guide line excluding intersections, the detector CPS does not have a detection signal, so the analog switches AS _RH and AS _LH are turned on and off.
Analog switches AS _RL and AS _LL are controlled off,
The detection signals from the pickups P _R and P _L are passed through high gain amplifiers R _H and L _H to detect deviations by the differential amplifier DA, and the steering angle is controlled with good response.
The unmanned vehicle can travel by following the guide line with high precision.

When the unmanned vehicle reaches the vicinity of the intersection, a detection signal is obtained from the detector CPS and the analog switch is activated.
AS _RH and AS _LH are turned off, AS _RL and AS _LL are turned on, and the detection signals from the pickups P _R and P _L are extracted through low gain amplifiers R _L and L _L , and the steering angle is adjusted according to the response up to that point. As a result, unmanned vehicles are less affected by signals from intersecting guide lines, and pass through intersections while being controlled in a gentle manner relative to the direction in which they enter the intersection.

Therefore, there is no need to decelerate when passing through an intersection, the unmanned vehicle is less likely to wander, and moreover, there is no derailment from the guideway, it is possible to obtain accurate steering control along the guideline, and cargo handling efficiency is improved.

In addition, in the embodiment, a case was shown in which the steering amount is limited by lowering the pick-up detection signal gain using the intersection detection signal, but this is a limiter control that limits the steering angle at intersections instead of gain switching. The same effect can be obtained by using other steering amount limiting means such as the above.

G. Effect of the invention As described above, according to the invention, since the amount of steering is limited by detecting that the vehicle is located near an intersection, the guidance line is less affected by magnetic fields from other guidance lines. It is possible to obtain proper steering without causing cargo collapse or derailment.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing one embodiment of the present invention;
The figure is a schematic diagram of the taxiway, and Figure 3 is a diagram of the magnetic field distribution at the intersection of the guideline. M...Unmanned vehicle, L...Guidance line, P _R , P _L ...Pick-up, R _H. R _L , L _H . L _L ...Amplifier,
AS _RH , AS _RL , AS _LH , AS _LL ...Analog switch, DA...Differential amplifier, CPL...Intersection signal generator, CPS...Signal detector, INV...Logic inverter.

Claims (1)

[Scope of utility model registration request] The strength of the magnetic field from the dielectric wire through which current is passed is detected by a pair of pick-ups on the left and right sides perpendicular to the front-rear direction of the unmanned vehicle, and the steering angle is adjusted in the direction where the deviation of the detection signals from both pick-ups becomes zero. A steering control device for an unmanned vehicle to be controlled includes an intersection detection means for detecting that the vehicle is located near an intersection of a plurality of guide lines, and a means for limiting the amount of steering when a detection signal is given from the detection means. A steering control device for an unmanned vehicle.