JPH031684B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a travel control device for a moving body that runs on tires.

[Prior art]

Conventionally, in transfer cranes, which run by rotating left and right rubber tires with separate right and left travel motors, in order to make the crane travel in a straight line, electric wires are embedded in the road surface parallel to the traveling direction.
The magnetic field strength emitted from this electric wire is captured by an antenna attached to the crane, and the magnetic field strength on both the left and right sides in the direction of travel is detected.The detection results are input to the control device, and if there is a difference between these input values on the left and right sides, the control system is activated. The device controls each motor so that the rotation speeds are unequal, and guides the crane in a direction where the left and right magnetic field strength measurement results are equal. In this way, the crane that was about to deviate from the power line was returned to the power line to prevent the crane from deviating from its travel course along the power line.

However, such conventional methods have drawbacks such as the hassle of burying the electric wires in the road surface, the fact that the buried road surface may crack under the load of the crane, and the use of electric wires increases the cost. Furthermore, when the crane trolley moves in the left-right direction, the load applied to the left and right rubber tires becomes uneven. For this reason, the amount of indentation of the left and right rubber tires becomes uneven, and a relative change occurs in the travel distance between the left and right sides of the crane.
The crane cannot move straight and tends to deviate from its travel course.

[Purpose of the invention]

An object of the present invention is to allow a moving body that runs on tires to travel in a straight line even if the position of the center of gravity of the moving body changes.

[Summary of the invention]

The present invention supports a moving body with left and right tires, and has separate left and right running motors that rotationally drive the left and right tires, and the moving body specifies the rotation speed of each of the running motors using human power based on detection results. In a moving body equipped with a control device that unevenly controls the vehicle so that it does not deviate from a straight running path, a measuring wheel is attached to the left and right sides of the moving body so as to be able to move vertically, and the measuring wheel is movable vertically integrally with the measuring wheel. left and right displacement detectors are installed between the moving member and the moving body with the measurement direction facing up and down, and the detection results of the displacement detectors are inputted to the control device as the measurement results. This is a travel control device for a moving body that uses left and right displacement detectors to detect the amount of dent in the left and right tires caused by the position of the center of gravity of the moving body. The motors are given unequal rotational speeds to make the moving object travel in a straight line.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 9.

Normally, as shown in Fig. 1, a container 1 is brought ashore from a ship 3 by a container crane 4, then transported by a trailer 5, and then lifted by a transfer crane 6 and transported to a yard. Stack on top.

The transfer crane 6, as shown in Fig. 2,
A girder 9 on which the trolley 8 runs as a frame;
It has both legs 10 that support the girder 9 and a track 17 that supports both legs 10, and rubber tires 13a, 13b, 13 are rotatably attached to the track 17.
c, 13d. Further, the trolley 8 is equipped with a lifting device for hoisting the container 1.

As shown in FIG. 3, a travel motor 12a attached to a truck 17, a reducer 15a that decelerates the rotation of the travel motor 12a, and a chain sprocket connected between the rotational output shaft of the reducer 15a and the wheels of rubber tires 13a. A rubber tire 13a can be rotationally driven by a travel motor 12a. Similarly, the rubber tire 13b
is rotationally driven by a travel motor 12b. In this way, the transfer crane 6 travels by rotating the left and right rubber tires 13a, 13b individually by the travel motors 12a, 12b.

Traveling inspection devices 14a are attached to the left and right trucks 17, respectively. Left and right running inspection device 1
4a is as follows. That is, as shown in FIG. 3, a bracket 14 is attached, and to this bracket 14, as shown in FIG. 4, a vertically long rod 24 is attached to a nut 23.
It is fixed at This rod 24 has cylinder 2
A coil spring 26 is installed between the bracket 14 and a sliding guide 22a fixed to the inner wall surface of the cylinder 22.
A saddle 21 having a freely rotatable inspection wheel 18 is fixed to the lower end of this cylinder 22. A cylinder side of a linear potentiometer 20 whose measurement direction is directed upward and downward is fixed to the bracket 14, and a vertically movable rod 27 of the linear potentiometer 20 is connected to a saddle 21 via a rod 28.
This linear potentiometer 20 moves a slider 35b of a variable resistor 35, to which a voltage is applied by a power source 35a, in conjunction with the vertical movement of the rod 27, as shown in FIG. 5, and generates a voltage proportional to the displacement of the rod 27. It can be output. Further, a link 25 that can bend freely at a shaft 25a is connected to the cylinder 22 from the bracket 14, and the cylinder 22 is prevented from rotating around the rod 24, so that the rotation of the cylinder 22 causes the rod 27 to rotate.
This prevents excessive lateral force from being applied to the rubber tires 13a and from moving the inspection wheels 18 in a direction different from that of the rubber tires 13a. An opto-encoder 19, which is a rotation speed detector, is connected to the axle of the inspection wheel 18, and the opto-encoder itself is installed on the saddle 21. As shown in FIG.
It has a rotary plate 29 with a slit 31 that rotates in response to the rotation of the axle, and emits the luminous flux from the sending diode 30a toward the slit 31, and the amount of light passing through the slit 31 is determined by the rotation speed of the rotary plate 29. The light receiving diode 30b receives the light passing through the slit 31, and the photoelectric conversion element 32 generates and outputs a pulse signal of an amount corresponding to the amount of light received. Therefore, the rotation speed of the inspection wheel 18 can be detected by the opto-encoder 19, and a pulse signal corresponding to the detected rotation speed can be output.

The output of the linear potentiometer 20 in the travel measuring device 14a as described above is converted into a digital signal by an analog-to-digital converter (A/D converter) 36, and then sent to a sixth signal via an interface circuit 34.
It is used as an input to the arithmetic unit 38 shown in the figure. The output of the opto-encoder 19 is converted into a digital signal by a frequency-to-digital converter (F-D converter) 33, and is input via an interface circuit 34 to an arithmetic unit 38 shown in FIG. Therefore, the rotation speed of the left and right inspection wheels 18 is determined by the opto encoder 19.
is input to the arithmetic unit 38 as a detection result. Further, since the inspection wheel 18 receives a pushing force from the road due to the dent in the rubber tires 13a and 13b, the cylinder 22 rises and pushes up the rod 27 of the linear potentiometer 20. Therefore, the amount of dent in the tires 13a, 13b is input to the arithmetic unit 38 as the detection results of the left and right linear potentiometers 20.

The calculation device 38 calculates the actual rotation speed N(n 2 ) of the rubber tire on one side from the rotation speed n ₂ of the inspection wheel 18 on one side among the left and right, and calculates the actual rotation speed N (n ₂ ) of the rubber tire on one side.
The actual rotation speed N (n ₄ ) of the rubber tire on the other side is determined from the rotation speed n ₄ of the rubber tire 13a,
Programs are set for calculating the actual tire radii R(δ ₂ ), R(δ ₄ ) of the tires 13a, 13b from the standard state of the tires 13b, taking into consideration the dent amounts δ ₂ , δ ₄ of the tires 13a, 13b. To briefly explain this program, the actual rotational speeds N(n ₂ ), N(n ₄ ) corresponding to the respective rotational speeds n ₂ , n ₄ and the respective dents corresponding to the occurrences of the respective dents δ ₂ , δ ₄ are calculated. Actual tire radius R (δ ₂ ), R (δ ₄ )
are set _in the _conversion data table ₄₂ shown in _FIG . ₂ , δ ₂ as data corresponding to R
(δ ₂ ) and R(δ ₄ ) are read from the table 42.

In addition, the calculation device 38 stores the actual tire radius R (δ ₂ ).
The field control circuit 41 of the motor 12a via the interface ₄₀ is inversely proportional to the ratio of
A program is set in which an output signal is output to the field control circuit 41b of the motor 12a and the motor 12b.

Furthermore, the traveling weight transfer distance X ₂ of each tire 13a, 13b from the crane start to the current time t,
X ₄ is X ₂ = 2π/60∫ ^t _p R(δ ₂ ). _N (n ₂ )dt ...(1) X ₄ =2π/60∫ ^t _p R(δ ₂ )・N(n ₄ )dt ...( ₂ ) motor 12a,
The field control circuit 4 sends a command to rotate the magnets 12b evenly.
The program sent to 1a and 41b is the arithmetic unit 3.
It is set to 8.

In this embodiment, when the trolley 8 that has lifted the container 1 is stopped at a position facing towards the rubber tire 13a side, the rubber tire 13a side (left side)
The rubber tires 13a and 13c are rubber tires 1.
3b side (right side) rubber tires 13b, 13d are dented more than the amount of dents caused by twisting δ ₂
The relationship between and δ ₄ is δ ₂ > δ ₄ , and the rotation radius of the left tires 13a and 13c during driving {actual tire radius R(δ ₂ )} is equal to the rotation radius of the right tires 13b and 13d {actual tire radius R(δ ₄ )}, and R(δ ₂ )<R(δ ₄ ). Therefore, as shown in Figure 8, the transfer crane 6 is moved to the left at an angle.
tries to bend. Therefore, the actual left tire radius R (δ ₂ ) determined from the detection result of the left linear potentiometer 20 is 1.1R, and the right actual tire radius R determined from the detection result of the right linear potentiometer 20. When (δ ₄ ) is 0.9R, an output signal is output from the calculation device 38 that provides a rotational speed of 1.1 times the rotation speed of the left travel motor 12a and a rotation speed of 0.9 times the rotation speed of the right travel motor 12b. The signal is sent to field control circuits 41a and 41b of each motor 12a and 12b. Therefore, both motors 12a and 1 are adjusted so that the rotation speed ratio N(n ₂ )/N(n ₄ ) becomes R(δ ₄ )/R(δ ₂ ).
2b can be controlled to have unequal rotational speeds. In this way, when the transfer crane 6 starts running, the rubber tire 13a, which has a large dent and has a smaller actual tire radius R (δ ₂ ) than the other side, replaces the rubber tire 1 on the other side.
3b, the transfer crane 6 can move straight without creating an angle.

Further, when the center of gravity G of the crane moves to the left side due to a change in the position of the trolley 8 while the transfer crane 6 is traveling, the crane tends to turn at an angle on the left side. In this case, the motors 12a and 12b are given unequal rotation speeds to return the motors to the right side in the same manner as described above. In this case, by continuing to return to the right side indefinitely, the crane 6 will turn from the straight travel course A to the right side. Therefore, the arithmetic unit 38 calculates the distance X ₂ traveled by the rubber tire 13a and the distance X ₄ traveled by the rubber tire 13b during the time t ₁ from the start to the present using the above equations (1) and (2). Calculate using the formula.
Then, when X ₂ = X ₄ , execution of the return to the right side is stopped. How to stop is by field control circuit 41a, 4
This is done by transmitting an output signal from the arithmetic unit 38 that makes the rotational speed of each motor 12a, 12b equal to 1b.

In addition, when calculating X ₂ and X ₄ , the radius of the inspection car 18 on the left is r _a and the number of rotations is n _a , and the radius of the inspection car 18 on the right is r _b and the number of rotations is n _b. In this _case , _{X 2} ^and _{X 4 are} ^calculated _{by the} arithmetic _{unit 38 as 2} = _X4
The return control may be stopped at the time of . In this case, N(n ₂ ), N(n ₄ ), R(δ ₂ ), R(δ ₄ )
can be omitted.

FIG. 9 shows another embodiment of the present invention, in which one travel measuring device 14a is installed on each side of the truck 17 in the forward and backward directions, two on the left side and two on the right side, for a total of four devices. The outputs of the two linear potentiometers 20 on the left side are averaged by the averaging circuit 44, and the outputs of the two opto-encoders 19 on the left side are averaged by the averaging circuit 44. Each output is transmitted to the arithmetic unit 38 side as a measurement result of the running inspection device 14a on the left side. The same applies to the right side. In this way, the measurement accuracy is improved and the reliability of the control is increased. Other parts are the same as the previous embodiment.

In each example, when sin≒ and cos≒1, the distances from the left and right sides of the center of gravity G are l ₁ and l ₂ , =-X ₂ -X ₄ /l ₁ +l ₂ =1/l ₂ +l ₂・2π／60∫ ^t1 ₀ [R
Focusing on the fact that (δ ₂ )・N(n ₂ )−R(δ ₄ )・N(n ₄ )dt, it is a factor that changes the condition required to maintain straight running performance = 0. By detecting δ ₂ and δ ₄ , R(δ ₂ )・N(n ₂ )−R(δ ₄
)・
The rotational speed of N( _{n 2 )} and N(n ₄ ) is controlled by each motor 12a, 12b so that N(n 4 )=0.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to achieve the effect that a moving body running on tires can be made to travel in a straight line even if the position of the center of gravity of the moving body changes.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a yard equipped with a transfer crane according to an embodiment of the present invention, FIG. 2 is a perspective view of the transfer crane shown in FIG. 1,
Fig. 3 is a detailed enlarged view of the track section of the transfer crane shown in Fig. 2, Fig. 4 is an enlarged view of the inspection equipment section shown in Fig. 3, and Fig. 5 is a detailed enlarged view of the track section of the transfer crane shown in Fig. 4. A schematic explanatory circuit diagram of the detector, Fig. 6 is a control block diagram of the transfer crane shown in Fig. 2, and Fig. 7 is a schematic explanatory circuit diagram of the detector.
The figure is an input/output explanatory diagram of the conversion table built into the arithmetic unit shown in Fig. 6, and Fig. 8 is a schematic plan view showing the relationship between the traveling state of the transfer crane shown in Fig. 2 and the crane's center of gravity. FIG. 9 is an elevational view of a track portion of a transfer crane according to another embodiment of the present invention. 6...Transfer crane, 8...Trolley, 9...Girder, 10...Leg, 12a, 12b...
...Motor 13a, 13b, 13c, 13d...Rubber tire, 14a...Inspection device, 18...Inspection wheel, 19...Opto encoder, 20...Linear potentiometer, 22...Cylinder, 24
... Rod, 26 ... Coil spring, 38 ... Arithmetic device, 41a, 41b ... Field control circuit.

Claims (1)

[Claims] 1. A moving body is supported by left and right tires, and has separate right and left running motors that rotationally drive the left and right tires, and the moving body moves in a specified straight line by inputting the detection results at the rotational speed of each of the running motors. In a moving body equipped with a control device that controls unevenly so as not to deviate from the road, a measuring wheel is attached to each of the left and right sides of the moving body so as to be movable up and down, and a member that moves up and down integrally with the inspection wheel. A moving object, characterized in that left and right displacement detectors are installed between the moving object and the measuring direction facing up and down, and the detection results of the displacement detectors are inputted to the control device as the measurement results. travel control device.