JPH02152900A - Rotary balancing material handling gear - Google Patents

Abstract

PURPOSE:To make a heavy load rotatively shiftable with light force without taking into account any dislocation of the center of gravity of a work by calculating weight of the work and added force with an arithmetic circuit, and constituting such one multiplying the value by a proper gain to be outputted to a rotary actuator as a speed command. CONSTITUTION:A speed command computing element 6 detects a vertical force with a vertical force detector 3a when it adds no force to a work, and stores a force signal Fy into a memory 7 as Fo. When adding force to the work, it inputs detected values Fy, Fx out of both vertical and horizontal force detectors 3a, 3b and a detected value theta out of an angle detector by way of an analog-to-digital converter 8. Then, Fy is compared with Fo by a first comparator 9, and both Sin and Cos components resolving the angle signal theta are multiplied by the vertical detection signal Fy-Fo and the horizontal detection signal Fx, thereby multiplying rotational operating force operated by a second comparator 10 by a proper gain Kx, and the value is converted by a digital-to- analog converter 11, thus it is outputted to a rotary actuator 4 as a speed signal v.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotary balanced cargo handling device in which an arm to which a work is attached is rotated in a vertical plane to raise and lower the work.

[Conventional technology]

A conventional device of this type is shown in Figure 8.
Arm rotation axis C of arm b that attaches workpiece a to the tip
and the output shaft e of the rotary actuator d that rotates it.
A torque detector f is provided between the arm b and the angle detector g of the arm b to determine the mold pan and operating force of the workpiece a.

[Problem to be solved by the invention]

In the above conventional rotary balanced cargo handling device, when determining the operating force (torque) applied by the operator to workpiece b from the torque T acting on arm b and the rotation angle θ of arm b, the center of gravity of workpiece a is the center of arm b. If it deviates from the line, there will be a deviation in the memorized value of the workpiece weight, which will cause an error in the torque due to the workpiece weight at each rotation angle, and an error will occur in the calculation of the operating force (torque) due to the workpiece weight applied by the operator. There was a problem in that the operating force applied by the worker could not be accurately determined.

That is, in FIG. 8, the weight of workpiece a is W, the length of arm b is θ, the rotation angle is θ, the torque acting on arm b is T, and the rotation angle at the time of heavy Ω memorization is θ. , the torque is T. ,
! When the In memory value is W, WLslnθ. -T, ----... (1) Now, as shown in Fig. 9, the center of gravity of workpiece a is shifted by dθ from the center line of arm b, and the distance from the rotation axis C of arm b is L. ', then WL' 5in(θ.-θd)-T.・・－－－(
2) From equations (1) and (2), the workpiece weight memory value W is as follows, and therefore, the torque Tw at an arbitrary position determined from the weight memory value is Tw-WL sinθ.

On the other hand, the torque Tw that actually acts due to the weight of the workpiece is Tw - WL' 5in (θ - dθ) - (5), but since it is not the same as the torque Tw determined by equations (4) and (5), Torque 2' due to workpiece weight cannot be determined accurately.

The torque applied by the operator is the total detected torque minus the torque caused by the weight of the workpiece, so the workpiece a
If there is a deviation in the torque applied by the operator, the exact torque applied by the operator cannot be determined, resulting in poor feedback.

In addition, in the conventional example described above, since a torque signal is used, when the workpiece a is located directly below the arm rotation axis C (θ-〇°), the generated torque is small, so a large error occurs in the workpiece weight memory. I had a problem with my memory.

The present invention was conceived in consideration of the above, and instead of the conventionally used torque detector, two
A directional force detector is used to detect both horizontal and vertical forces acting on the arm rotation axis to calculate the weight of the workpiece, etc. Even if the center of gravity of the workpiece is off the center line of the arm, the weight of the workpiece can be calculated. It can be directly determined from the vertical force acting on the arm rotation axis, and the weight memory can also be determined in the same way at any rotation angle, so the workpiece weight memory is (
To provide a rotationally balanced load handling device that can rotate and move a heavy object at a desired position and with a light force without considering the shift of the center of gravity of the work.

[Means to solve the problem]

In order to achieve the above object, the rotary balanced load handling device according to the present invention is a rotary balanced load handling device in which the arm to which the work is attached is rotated in a vertical plane by a rotary actuator to raise and lower the work. An angle detector that detects the rotation angle, a force detector that detects the force applied to the arm, and a calculation circuit that receives the force signal from the force detection and the angle signal from the angle detector and calculates the weight of the workpiece and the operator. It is composed of a speed command calculator that calculates the force applied by the rotary actuator, multiplies the value by an appropriate gain, and outputs the result as a speed command to the rotary actuator.

[For production]

The angle detector receives the vertical force signal and the vertical force signal from the force detector, and the angle signal from the angle detector, and then outputs the force signals stored in advance in a state in which no work force is applied and the above-mentioned force signals. The signals are compared and calculated, and a signal obtained by multiplying the value by an appropriate gain is output to the rotary actuator as a speed command signal.

〔Example〕

Embodiments of the present invention will be described based on FIGS. 1 to 7.

FIG. 1 schematically shows the configuration of a rotary balanced load handling device according to the present invention. In the figure, 1 is an arm to which a workpiece 2 is attached at the tip, and this arm 1 is connected to a support via a force detector 3.3. is rotatably supported. 4 is a rotary actuator that rotates the arm 2, and 5 is an angle detector that detects the rotation angle of the arm 2. Further, 6 is an angle command calculator.

The force detector 3 uses a pin-type load cell that can measure forces in two directions, horizontal (x) and vertical (y).
), the force in the vertical (y) direction is detected, and force detection signals in the x and y directions, that is, the horizontal force signal Fx and the vertical force signal FV are output, respectively.

The angle command calculator 6 calculates based on the horizontal and vertical force signals Fx, Fy and the angle signal θ from the angle detector 5, and outputs a speed command signal V to the rotary actuator 4 as a result. It has become.

The operation in the above configuration will be explained.

([) When storing workpiece weight (Figures 2 and 3) If the weight of workpiece 2 is W1 and the weight of arm 1 is Wa, then when the worker is not applying force to workpiece 2, F g -W Since the relationship +W a holds true, the vertical force at this time is detected by the vertical force detector 3a of the force detectors 3, and the force signal Fy at this time is stored in the storage device 7. Close it and memorize it. The relationship between the forces acting on the arm 2 at this time is as shown in FIG.

(2) During operation (Figures 4 and 5) When the operator applies force to the workpiece 2, the detected value Fy from the vertical force detector 3a and the horizontal force detector 3b of the force detector 3 , Fx, and the detected value θ from the angle detector 5 is A
/D converter 8. The vertical force signal Fy is compared Fy-FO by the first comparator 9, and the angle signal θ is decomposed into a sin component and a cosine component θ, and the angle signals sinθ and cosθ of the respective components are
is multiplied by the vertical force detection signal Fy-Fo and the horizontal force detection signal Fx, and the second comparator 10 calculates f-Fx cos θ-(F y-Fo ) sin θ based on this value. As shown in FIG. 5, f is the operating force in the rotational direction perpendicular to the arm 2 of the operating force.

This rotational direction operating force f is multiplied by an appropriate gain Kx, and the resulting signal is converted by a D/A converter 11 and output as a speed command signal V to the rotary actuator 4.

This speed command determines the rotational direction operating force (
The workpiece 2 is rotated at a speed proportional to the tangential force (tangential force) f.

In addition, at this time, if the gain K is set to a large value, the operator does not feel any friction, and can swing the heavy object with a light force by directly applying the child to the workpiece 2.

The above embodiment shows an example in which the force detector 3 is fixed to the support part side, but as shown in FIG. The force in the horizontal direction (radial direction of rotation) is Fr, and the force in the vertical direction (
If we detect the force Ft (tangential direction), in Fig. 6,
When the operator does not apply any operating force, W+Wa-FrCO5θ-Ftslnθ=F.

Therefore, F at this time. If you remember, the force f in the tangential direction when the worker applies force is f - F t +F
, sinθ (', °F t −f −(W+W a ) sinθ
), it is possible to move the workpiece 2 with a light force using the rotary actuator 4 in the same manner as in the first embodiment.

FIG. 7 shows a schematic cross-sectional structure of the arm rotating shaft portion when the force detector 3 is fixed to the support portion side of the arm 1.

〔Effect of the invention〕

According to the present invention, even if the center of gravity of the workpiece 2 deviates from the center line of the arm 1, the weight of the workpiece can be directly absorbed from the vertical force acting on the arm rotation axis, and the weight can be stored at any time. The rotation angle can be determined in the same way, so the weight of the workpiece can be stored at any position, and a heavy object can be rotated with a light force without considering the shift of the center of gravity of the workpiece.

[Brief explanation of the drawing]

1 to 7 show embodiments of the present invention.
The figure is a schematic explanatory diagram of the overall configuration, Figure 2 is a block diagram showing the action of the speed command device when storing the weight of a workpiece, and Figure 3 is an explanatory diagram showing the coordinate system of the force acting on the arm when storing the weight. ,
Figure 4 is a block diagram showing the action of the speed command calculator during operation, Figure 5 is an explanatory diagram showing the coordinate system of the force acting on the arm during operation, and Figure 6 is a force detector on the rotation axis of the arm. FIG. 7 is an explanatory diagram showing the coordinate system of the force acting on the arm in an embodiment in which the arm is fixed, and FIG. 7 is a schematic cross-sectional view showing the arm rotation axis when the force detector is fixed to the supporting part side of the arm. FIGS. 8 and 9 are explanatory diagrams showing conventional examples. 1.1° is an arm, 2 is a workpiece, 3 is a force detector, 4 is a rotary actuator, 5 is an angle detector, and 6 is a speed command calculator.

Claims (1)

[Claims] An angle for detecting the rotation angle of the arms 1, 1' in a rotary balanced cargo handling device in which the arms 1, 1' to which the work 2 is attached are rotated in a vertical plane by a rotary actuator 4 to raise and lower the work 2. A detector 5, a force detector 3, 3' that detects the force applied to the arm 1, 1', and a force detector 3, 3
'The force signal from the angle detector 5 is received and the angle signal from the angle detector 5 is received, and the arithmetic circuit calculates the weight of the workpiece 2 and the force applied by the worker, and multiplies the calculated value by an appropriate gain to the rotary actuator 4. A rotary balanced cargo handling device comprising a speed command calculator 6 which outputs a speed command as a speed command.