JPH1072198A - Control device of cargo handling material carrier by force control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of an inverse signal, and obtain stability in the aspect of operability by arranging an operation part by incorporating a spring whose one end part is connected to an upper surface of a grip part and other end part is connected to a force sensor. SOLUTION: When a grip part 12b is tried to be raised, its raising force is transmitted in order to the grip part 12b, a spring 12c and a force sensor 12a, and the force sensor 12a converts received force into an electric signal, and transmits it to a control base board 14a through an electric wire 15. The control base board 14a performs amplifying processing on the electric signal, and inputs it to an electropneumatic proportional valve 14b. The electropneumatic proportional valve 14b adjusts pressure of a cylinder 11 so as to become pressure in proportion to the electric signal. A cargo handling material 16 is hung up or lowered by a hook 13. Therefore, since a force signal is stable, vibration and hunting of an operation part are not caused.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cargo handling machine having a lifting / lowering mechanism such as a parallelogram link type or a jib type, and a force control method for lifting and lowering the cargo using an actuator such as an air cylinder or an electric motor. Related to the control device.

[0002]

2. Description of the Related Art Conventionally, in a cargo handling machine that performs this type of force control, the magnitude of a lifting force in the antigravity direction that is output when a person attempts to lift a cargo is determined by an operation unit or its vicinity. A force sensor was installed to directly detect the force applied to the grip and lift the cargo. (See Japanese Patent Application No. 7-354942)

[0003]

SUMMARY OF THE INVENTION With respect to the conventional method,
If you describe its contents and problems, humans have an operation unit,
The magnitude of the lifting force in the anti-gravity direction issued when trying to lift the cargo is detected by the operation unit or a force sensor provided near the operation unit. In the lifting / lowering by the signal of the force sensor, when the lifting / lowering is stopped (balance state) or the amplification degree of the force signal (F2 / F1: F1 is a lifting force of a human, F2 is a lifting force of a cargo handling machine). When transferring a light object against the rated load when it is large,
There is a problem that the operation unit vibrates and hunts.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems and is characterized in that a mechanical connection is made between a force sensor provided on an operation unit and a grip unit via a spring. It is a control device of the cargo handling machine. Next, an embodiment of the present invention will be described with reference to FIG. 1. FIG. 1 is a conceptual diagram of the embodiment. A cargo handling machine having a parallel link mechanism and driven manually in the horizontal direction and by power in the vertical direction.
One end of an A-arm 4 is fixed to a fixed shaft 5 on a side plate of a main body 3 connected via a revolving base 2 to the other end of a C-arm 7 via a support shaft 6. Connect, link arm 8, B arm 9, A arm 4 and C arm 7
Form a parallel link mechanism. Also, swivel 2
A guide is provided for supporting the power point 10 of the parallel link mechanism in a direction perpendicular to the rotation axis of the rotary arm, and the cylinder 11 capable of moving up and down in parallel with the rotation axis of the swivel 2 raises and lowers the power point 10 of the parallel link. 7 is provided with an operating unit 12 incorporating a spring 12c having one end connected to the upper surface of the grip unit 12b and the other end connected to a force sensor 12a, and a hook for suspending a load on the operating unit 12. 13 is provided.

The control unit 14 is composed of a control board 14a and an electropneumatic proportional valve 14b, and the force sensor 12a and the control board 14a
5, the control board 14a is connected to the electropneumatic proportional valve 14b.
Connected to. The electropneumatic proportional valve 14b is connected to the cylinder 11 via an air pipe. FIG. 2 shows a waveform of a force signal with respect to a time axis in the related art, which is a waveform when the cargo is lifted from the ground and stopped in the air. FIG. 3 shows a waveform of a force signal with respect to a time axis according to an embodiment of the present invention, which is a waveform when the cargo is lifted from the ground and stopped in the air in the same manner as described above.

[0006]

According to the operation described above, when the grip portion 12b is lifted, the lifting force is transmitted to the grip portion 12b, the spring 12c, and the force sensor 12a in this order, and the force sensor 12a converts the received force into an electric signal. The signal is converted and transmitted to the control board 14a through the electric wire 15. The control board 14a amplifies the electric signal and generates an electropneumatic proportional valve 14b.
To enter. The electropneumatic proportional valve 14b adjusts the pressure of the cylinder 11 so that the pressure becomes proportional to the electric signal.
To lift the cargo 16 by the hook 13
2b, the force sensor 1 via the spring 12c
The force F1 applied to 2a is increased by the control unit 14, the cylinder 11, and the parallel link mechanism, becomes a lifting force F2, acts on the operation unit 12, and W <F1 + F2, so that the cargo 16 is lifted. In addition, the force F lifting the grip portion 12b
When 1 is weakened, W> F1 + F2, and the cargo 16 is lowered. Here, using FIG. 2 and FIG. 3 to describe in detail the effect of mechanical connection by inserting a spring 12c between the grip portion 12b and the force sensor 12a, FIG. 2 and FIG. It is a waveform diagram of the force signal with respect to the time axis when the cargo is lifted from the ground and stopped in the air. FIG. 2 is a waveform diagram of a force signal according to the related art. In section B, a change in the force signal is seen. On the other hand, FIG. 3 is a waveform diagram of the force signal in the embodiment of the present invention. In the section D, no change in the force signal is observed despite the same operation. Therefore, since the force signal is stable, vibration and hunting of the operation unit do not occur.

[0007]

From the above configuration and operation, the effect can be described. In the force control in which the control is performed by the magnitude of the force in the ascending direction when the person tries to lift the cargo, Immediate ascent and descent are possible as there is a response of force immediately to the force that is being issued. However, when the robot is slowly moved up and down or in a balanced state, an inverse signal may be input, and the operation unit is in a vibration / hunting state. In the present invention, since a reverse signal can be prevented from being generated by interposing a spring between the grip portion and the force sensor, there is a great effect that stability which has not been conventionally obtained in terms of operability. In addition, when a light object is transferred with respect to the rated load when the amplification of the force signal is large, the operation section can be vibrated by removing the force signal that is not intended by humans by using a spring.
The hunting phenomenon was prevented. By that,
Regardless of the skill or working posture of operating the machine, it is possible to perform operations consistent with natural human movements. Further, there is a great effect that the force felt by a human hand is reduced when the operation unit is raised from a state where the cargo is lifted or stopped from being lowered.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an embodiment of the present invention.

FIG. 2 is a waveform diagram of a force signal in the related art.

FIG. 3 is a waveform diagram of a force signal according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 support 2 turntable 3 main body 4 A arm 5 fixed shaft 6 support shaft 7 C arm 8 link arm 9 B arm 10 force point 11 cylinder 12 operation unit 12a force sensor 12b grip unit 12c spring 13 hook 14 control unit 14a control board 14b Electropneumatic proportional valve 15 Electric wire 16 Cargo material F1 Lifting force of human (force in anti-gravity direction) F2 Lifting force of cargo handling machine W Weight of cargo

Claims (1)

[Claims] In a cargo handling machine for performing force control, a mechanical connection is established between a force sensor incorporated in an operation section and a grip portion via a spring.