JPH0225522B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling a moving object such as a trackless truck, crane, forklift, etc., which receives signals from a laid guide line and travels along the guide line.

Conventionally, the control method used to control the running of trackless cranes can measure not only the amount of positional deviation in the lateral direction with respect to the crane's running direction, but also momentary changes, so the lateral velocity and acceleration must be calculated at the same time. It was composed of analog circuits.

If the lateral velocity or acceleration is used as a signal for determining a correction signal, the control device must have a differentiating circuit for differentiating the positional deviation detector signal.

By the way, since the lateral displacement speed and acceleration of a crane generally have small values to begin with, the output from the differential circuit that obtains them will be a very small value, so this signal must be sufficiently amplified when used as a correction judgment signal. The need arose. On the other hand,
Difficulties remain in constructing a stable control system, such as the differential circuit outputting a high output against noise contained in the detector 13 and the control system.

In addition, in the conventional technology, since the control device was constructed of an analog system, it was not possible to keep a history of the amount of positional deviation and the calculation results.

An object of the present invention is to provide a stable control method.

The present invention calculates the difference A in the amount of positional deviation per unit time T from the amount of positional deviation E _t with respect to the reference line, compares the difference A in the amount of positional deviation with a set value K, and calculates the difference in the amount of positional deviation per unit time T. When the difference A is larger than the set value K, determine whether or not steering is necessary based on the positive or negative of the positional deviation amount E _t and the positive or negative of the difference A between the positional deviations, and output a steering signal if necessary. It is characterized by:

An embodiment of the present invention will be described below with reference to FIGS. 1 to 7.

As shown in FIG. 1, the trackless crane to which the control device according to the present embodiment is applied receives the magnetic flux from the guide wire 8 at the positional deviation detector 7, and detects the absolute amount of positional deviation and the positional deviation per unit time. If the amount is larger than a specified value, control is performed by switching the fields of the DC motors 1 and 2 to give a speed difference to the drive wheels 3 and 6. 4 and 5 are free wheels.

FIG. 2 shows a block diagram of this control device.

The positional deviation detector 7 receives magnetic flux from the guide wire 8 and detects the amount of positional deviation of the crane with respect to the guide wire 8 . When the positional deviation amount E is taken horizontally and the detector output F is taken vertically, the positional deviation detector 7 outputs a voltage F which has characteristics as shown in FIG. 4 and is proportional to the positional deviation amount E.

A low-pass filter 9 removes high-frequency noise contained in the positional deviation detection output F. The A/D converter 10 converts the positional deviation amount E into a digital amount, and enables numerical calculation within the microcomputer 11.

This will be explained below with reference to the flowchart shown in FIG.

Any one of relays 12, 13, and 14 (generally relay 13 at startup) is turned on, and the crane is traveling. Figures 6 and 7 depict the traveling locus H of the crane's positional deviation detector 7, and the positional deviation amount E _t detected by the positional deviation detector 7 and converted into a digital amount (Fig. 4). Same as positional deviation amount E)
The microcomputer 11 that has taken in the value Et first stores the taken-in value _Et , and in step S1, this value, that is, the amount of positional deviation _Et, is set to the absolute specified value C.
Check whether it has exceeded the limit. Here, the specified value C is
This refers to the minimum amount of positional deviation that must be corrected in advance.

As shown in FIG. 5, the positional deviation detector 7 is
On the other hand, going to the left side I gives a positive output, and going to the right side K gives a negative output. When the initial value is within the specified value C as shown in FIGS. 6 and 7, the process moves to step S5.

This will be explained below with reference to FIG.

The microcomputer 11 detects the positional deviation amount E _t of the positional deviation detector 7 of the crane that has started traveling in FIG.
After capturing and storing the value every T seconds for a certain period of time, the difference A from the value stored T seconds ago is taken and compared with the set value K, and the difference A in positional deviation amount for T seconds is acceptable with respect to the set value K. It is determined whether the information is true (step S5).

If A is greater than or equal to the set value K, it is determined that the tendency of positional deviation is large, and a determination is made to operate either of the correction relays 12 and 14 in FIG. 2 (step S7). In the case of FIG. 6, if the direction of the crane is away from the guide line 8, the relay 12 is operated to turn on the contact 12A,
By increasing the current flowing through the field winding 18 of the DC motor 1 and at the same time decreasing the current flowing through the field winding 19 of the DC motor 2, the driving wheel 3 driven by the DC motor 1 is moved from the DC motor 2. The speed of the drive wheels 6 driven by the drive wheels 6 is relatively increased to control the running direction (step S9).

The determination in step S7 is made as follows.
That is, it is determined whether the crane is traveling toward the guide line 8 based on the traveling direction of the crane and the position of the crane, and if the crane is traveling in a direction away from the guide line 8, the guide line 8 is determined. The rotational speed of one of the motors 1 and 2 is increased relative to the other so as to point toward line 8. To explain in detail, the determination is made based on whether the positional deviation amount E _t of the positional deviation detector 7 is positive or not, and whether the difference A between the positional deviation amounts in T seconds is positive. In Figure 6, E _t is positive, A is positive, and the direction of the crane is toward guide line 8.
A′ is negative. Positional deviation amount of positional deviation detector 7
If E _t is positive and the difference A in the amount of positional deviation is positive, the relay 12 is turned on. Other relays are OFF
let On the other hand, if the positional deviation amount E _t is negative and the difference A between the positional deviation amounts is negative, the relay 14 is turned on. Turn off other relays. For other combinations, the current status is maintained. step
A table can be used to determine S7. In addition,
Except for step S7, C, A, and _Et are absolute values. In step S1, if the positional deviation amount _Et is larger than the specified value C as shown in FIG.
Move on to S15.

In step S15, if the positional deviation amount _Et is positive, the relay 12 is turned on to direct the crane toward the guide line 8 side. If the positional deviation amount E _t is negative, the relay 14 is turned on.

This is performed at intervals of T seconds in step S17.

In this way, by comparing the difference A in the amount of positional deviation per unit time T with the set value K, it is possible to grasp the driving situation necessary for driving direction control, and the relay is switched based on this driving situation, so it is easy to use. This method makes it possible to control the movement of the crane, and since no differential circuit is used in the control system, stable control is possible.

As described above, according to the present invention, automatic running direction control of a trackless moving body can be achieved without using a conventional differentiation circuit, and therefore, stable control can be achieved.

[Brief explanation of drawings]

FIG. 1 is an external view of a trackless crane to which a control device according to an embodiment of the present invention is applied, FIG. 2 is a block diagram of a control device according to an embodiment of the present invention, and FIG.
The figure is a field switching circuit diagram of the motor shown in Fig. 1, and Fig. 4 is a characteristic diagram of the position deviation detector shown in Fig. 1.
FIG. 5 is a plan view showing the running direction and arrangement of electric motors of the trackless crane shown in FIG. 1, FIGS. 6 and 7 are running trajectory diagrams of the trackless crane according to an embodiment of the present invention, and FIG. It is a flowchart of one example of control of the present invention. 1, 2... DC motor, 3, 6... Drive wheel,
4, 5...Free wheel, 7...Position shift detector, 8...
...Guiding wire, 9...Low pass filter, 10...
A/D converter, 11... microcomputer,
12, 14... Correction relay, 13... Normal field relay, 18, 19... Field wire of DC motor.

Claims (1)

[Claims] 1. The left and right drive wheels in the traveling direction of the moving body are each equipped with an electric motor that can be operated independently, and the amount of positional deviation E _t with respect to a reference line arranged in the traveling direction of the moving body is determined. , in a method for controlling a trackless moving object that determines the amount of steering by the two electric motors based on the positional deviation amount E _t , when the positional deviation amount E _t is smaller than a reference value C, the positional deviation amount E _t is Therefore, unit time T
Find the positional deviation amount A per hit, compare the positional deviation amount with the set value K, and if the positional deviation amount A is larger than the set value K, the positional deviation amount E _t is positive and the above-mentioned Determine whether the combination is such that the positional deviation amount A is positive, or the combination in which the positional deviation amount E _t is negative and the positional deviation amount A is negative; E _t
is larger than a reference value C, outputting a signal so that a difference in rotational speed is generated between the two electric motors so that the moving direction of the moving object is opposite to the reference value C. Control method for trackless moving objects.