JPS6279991A - Multidegree-of-freedom arm type inspection device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a multi-obviousness arm-type inspection device used for remote inspection work, etc., and is particularly suitable for use in narrow spaces where work conditions are severe in nuclear reactor facilities, etc. The present invention relates to a multi-degree-of-freedom arm type inspection device suitable for performing inspection work.

[Background of the invention]

In recent years, remote inspection systems have been developed to inspect the health of equipment housed in nuclear facilities and the like. This type of remote inspection system is 1, for example, Kinki Giho (No. 5
3, published in March 1985), pages 95 to 102, "About the development of a remote inspection system in the cells of the Tokai reprocessing plant" (author Yuzo Ishibashi), and a television camera with an electric zoom lens is attached to the tip. A system has been proposed that uses a multi-joint arm type inspection device to perform remote inspection work on various equipment at nuclear facilities and the like.

By the way, the multi-degree-of-freedom arm used in such a remote inspection device can generally be of various types, but for example, when using one similar to an industrial robot used in a production factory, etc. The arm's own weight is heavy, hundreds of pounds, compared to the handling load of several hundred pounds, making it impossible to transport by hand.The multi-degree-of-freedom arm must either be fixed or supported by a large-scale transportation device. Ta. In addition, joint drive systems for multi-degree-of-freedom arms generally place the arm drive motors centrally on the drive device side, and transmit the motor drive power to the arm drive mechanism using wires or chains, or There is a method that directly drives the articulated arm by arranging a wire or chain, but the structure is complicated and there are problems with control accuracy due to the longevity and length of the wire. The method of arranging a motor for each arm requires a large torque due to the large weight of the arm, and the arm as a whole becomes large, making it unsuitable for inspecting narrow spaces.

Furthermore, a multi-degree-of-freedom arm is normally driven by a DC servo motor, but when a visual device that is easily affected by vibrations, such as a television camera with a zoom lens, is attached to the end of the arm, a servo motor that is extremely difficult to maintain the arm's posture is required. Lock performance was required.

[Object of the Invention] The present invention has been made in view of the above points, and its purpose is to enable installation and transportation in narrow spaces, facilitate disassembly and assembly, and An object of the present invention is to provide a multi-degree-of-freedom arm-shaped inspection device that can perform remote inspection operations with high precision and ease.

[Summary of the invention]

In order to achieve the above object, the present invention includes a multi-degree-of-freedom arm that is equipped with a visual device for inspecting an object at its tip, and remotely controlled while monitoring the multi-degree-of-freedom arm with a monitor device. In the remote-controlled multi-degree-of-freedom arm-type inspection device, the multi-degree-of-freedom arm is alternately rotated so that each of a plurality of vertical swinging arm members and horizontal swinging arm members can be rotated vertically or horizontally. The vertical swinging arm member and the left and right swinging arm member each include a worm and a worm for vertically moving or horizontally rotating each arm member. A joint drive mechanism consisting of wheels is disposed, a plurality of drive motors for driving the drive mechanism are housed in a drive unit formed separately from the multi-degree-of-freedom arm, and the horizontal swing arm member and the vertical swing A plurality of flexible shafts for transmitting rotational force to each of the joint drive mechanisms described above are passed through the interior of the arm member, and one end of each of the flexible shafts is connected to a worm of each of the joint drive mechanisms described above. The other end is detachably connected to the drive motor housed in the drive unit via a slide joint, and the multi-degree-of-freedom arm is detachably fixed to the drive unit.

According to the present invention having such a configuration, there is no need to provide a drive motor for driving the multi-degree-of-freedom arm in each arm member of the multi-degree-of-freedom arm, and the internal structure within the multi-degree-of-freedom arm is simplified. Therefore, the multi-degree-of-freedom arm can be made small (
It can be made lightweight and has a small diameter, making inspection work in narrow spaces possible. Furthermore, the multi-degree-of-freedom arm is small and lightweight, making it easy to transport, and the multi-degree-of-freedom arm and drive unit can be disassembled and assembled at a work site. Then, when the drive motor is driven via the remote operation means, the worm and worm wheel of each joint drive mechanism are operated via the flexible shaft, and the vertical swing arm member and the left and right swing arm member are moved up and down.

The multi-degree-of-freedom arm rotates by a predetermined amount to either the left or right, and reaches the position of the object to be inspected while performing arbitrary bending movements within the narrow space. In particular, when performing such movements, an elastic force acts on the flexible shaft following the bending movement of the multi-degree-of-freedom arm, but since the flexible shaft is connected to a slide joint, this elastic force is absorbed. Rotation transmission operation can be performed without any trouble. In addition, the torsion of the flexible shaft itself is reduced to 1 of the gear dead force of the worm and worm wheel of the indirect drive mechanism, and the indirect drive mechanism drives each arm member of the multi-degree-of-freedom arm with high precision. When the mechanism stops, the worm and worm wheel have a self-locking function that keeps the multi-degree-of-freedom arm in a stable, immobile state, and the visual device installed at the end of the multi-degree-of-freedom arm captures the object to be inspected without shaking. be able to.

[Embodiments of the invention]

An embodiment of the present invention will be described based on FIGS. 1 to 11.

FIG. 1 shows a state diagram in which a multi-degree-of-freedom arm-type inspection device, which is an embodiment of the present invention, is used for inspecting the inside of a cell in a nuclear reactor reprocessing plant. The inspection device includes a multi-degree-of-freedom arm 1 equipped with a visual device 2 at its tip, and a role of guiding the insertion and withdrawal of the multi-degree-of-freedom arm 1 and suspending a surveillance television camera 4 and a lighting lamp 5 for the television camera. A drive unit 6 that houses a drive source for driving the multi-degree-of-freedom arm 1, a moving unit 7 that movably supports the drive unit 6 with casters for movement, and a remote control unit shown in FIG. Multi-degree-of-freedom arm control as shown in the inspection system *fl! 10. calculator 1
1. Visual device control device 12, visual information processing device 13.
It is composed of a control unit 8 that houses an operation section 14, and a monitoring unit 9 that includes an information display device 15 that displays visual information. 16 is a concrete cell structure, 1
7 is an inspection hole provided in the concrete wall, and 18 is an object to be inspected.

FIGS. 2 and 3 are schematic diagrams of the configuration of the multi-degree-of-freedom arm 1. As shown in FIG. It is composed of multi-articulated arms that are connected alternately.
A holding arm 20 for removably fixing the multi-degree-of-freedom arm 1 to the side surface of the drive unit 6 is connected to its base end. Further, at the tip of the multi-degree-of-freedom arm 1, there is a television camera 30 that constitutes the visual device 2. zoom lens 3
1. Scanning mirror 32. Lighting 33 is installed. Vertical swing arm member 21. Left and right swing arm member 22
．． The inside of the holding arm 20.

As shown in FIG. 3, each arm member 2 is formed into a hollow shape.
A worm 23 (23') and a fan-shaped worm wheel 24 (24') for driving an arm as described later are arranged in the hollow interior of 1.22, and each worm 2
A plurality of flexible shafts 25 for rotation transmission are pushed through to connect the drive motors 26 (direct current motors with deceleration) 26 housed in the drive unit 5 side.

4 and 5 show the internal structure of an arm in which a worm 23 and a worm wheel 24 for vertical swinging are arranged.
A rotating shaft 28 to which the worm wheel 24 is fixed is horizontally attached to the tip side of the left-right swinging arm 22 , and the rear end of the vertical swinging arm member 21 is fixed to both ends of the rotating shaft 28 . A worm 23 is engaged with the side. In addition, a flexible shaft 25 is attached to one end of the worm 23 at the connecting portion 2.
It is fixed via 9. Therefore, when the flexible shaft 25 is rotated by the drive motor 26, the worm 2
3 rotates, the rotation angle of the worm 23 is reduced by the dead force of the gear with the worm wheel 24, and is transmitted to the worm 24, causing the vertical swinging arm member 21 to rotate in the vertical direction. The flexible shaft 25 incorporates an inner shaft that is a spring-like rotation transmission mechanism, and the rotation angle of the drive motor 26 is the same as that of the flexible shaft 25. This is the rotation angle of the worm 23. Note that the reference numeral 25 near the center position in FIG. 5 indicates a worm 23 installed on another arm member.
(23') flexible shaft connected to 30
is a cable for controlling the visual device 2.

Figures 6 and 7 show the internal structure of an arm in which a worm 23' and a worm wheel 24' for horizontal swinging are arranged, and the worm wheel 24' is pivoted perpendicularly to the tip of the vertical swinging arm member 21. The rear end of the left-right swinging arm member 22 is fixed to both ends of the rotating shaft 31 in the horizontal direction, and the worm 23' is engaged with the worm wheel 24'. A flexible shaft 25 is connected to one end of the worm 23' via a connecting portion 29, and rotation of the flexible shaft 25 causes the left-right swing arm 22 to rotate in the left-right direction via the worm 23' and the worm wheel 24'. .

FIG. 8 shows the connection structure between the flexible shaft 25 and the drive motor 26. A torque limiter 32 is attached to the output side of the drive motor 26, so that even when the multi-degree-of-freedom arm 1 comes into contact with an obstacle, the flexible shaft 25 This prevents excessive torque from being applied to the Further, a spline shaft 27a constituting the slide joint 27 is attached to one end of the flexible shaft 25, and this spline shaft 27a is slidably and removably attached to a joint body 27b provided on the output side of the torque limiter 32. ing. 3
3 is a potentiometer that detects rotational displacement of the torque limiter 32 via a gear 34. FIG. 9 is a schematic diagram showing the control system of the arm drive mechanism in the multi-degree-of-freedom arm 1. When a drive signal is issued from the operating section 14 to the drive motor 26 via the arm control device 10, the multi-degree-of-freedom arm 1 In this case, each arm 21 of the multi-degree-of-freedom arm 1
．． The amount of movement of the joint 22 is detected by the potentiometer 33, and this detection signal and the command value of the operating section 14 are constantly compared and controlled to control the position so that the deviation becomes zero. 35 is a CRT that three-dimensionally displays the shape of the multi-degree-of-freedom arm 1 processed by the computer 11. In this example, in order to make it easier to understand the directionality of the arm shape three-dimensionally, The viewing direction is calculated by the computer 11 and displayed as a dotted line on the CRT 35, and the cell wall surface reached by the dotted line is colored. Also,
Reference numeral 36 denotes a contact sensor that detects when each arm member 21, 22 of the multi-degree-of-freedom arm 1 comes into contact with a wall surface or other obstacle during a bending motion. 9 in the circumferential direction on the outer periphery of the arm member 21 and the left-right swinging arm member 22 and these joints.
The signals from the contact sensor 36 are processed by the computer 11, and the number of the arm member of the contact part and the direction of contact are displayed on the CRT 35, and at the same time the motor 26 is operated. It is set to stop (interlock).

In the above control system, an error occurs in the signal amount of the potentiometer 33 by the amount of torsion angle (backlash) between the worm 23 (23') and the rotary conductive flexible shaft 25. If the reduction ratio of the wheel 24 is set to about 70, the swing angle of the left-right swinging arm 22 at the tip of the multi-degree-of-freedom arm 1, where the flexible shaft 25 is the longest, is 1 to 2 degrees, which improves the accuracy of use of this device. There is no problem from this point of view.

FIG. 10 shows a specific example of a guide tube 3 for guiding the multi-degree-of-freedom arm 1 into and out of a building. Multi-degree-of-freedom arm 1 is placed on the camera mount 37.
A back-up surveillance television camera 4 and lighting 5 are installed to monitor the shape of the arm 1 and interference objects in the surroundings to facilitate operation of the multi-degree-of-freedom arm 1. When inserting the guide tube 3 into the inspection hole 17, the camera mount 37 is held in a horizontal state so as not to hinder the insertion, and after insertion, the wire 38 holding the tip of the mount 37 is used to operate the handle 39. Unscrewed camera 4. The lighting system 5 is suspended by its own weight, and the center of the guide tube 3 is made into a cavity free of obstacles, making it easy to insert the multi-degree-of-freedom arm 1 along the rollers 40.

Next, the operation of this embodiment will be explained.

For example, when inspecting the inside of a cell of a nuclear reactor building etc. by remote control, the inspection floor F is equipped with a multi-degree-of-freedom arm ψ 1, an insertion arm, a drive unit 6, a moving unit 7,
The control unit 8, monitoring unit 9, guide tube 3, etc. are transported in a divided state, and these components are electrically connected by connectors.Then, after the guide tube 3 is installed in the inspection hole 17, it is monitored by the surveillance television camera 4. The multi-DOF arm 1 is inserted while being monitored by the device 9, and then the multi-DOF arm 1 and the drive unit 6 are connected via the holding arm 20, and each of the flexible shafts 25 into which the multi-DOF arm 1 is inserted is connected. One end is splined shaft 27
A is connected to the output side of the drive motor 26 by coupling the joint body 27b.

Next, while monitoring the multi-degree-of-freedom arm 1 on the monitor screen of the surveillance television camera 4, when the operation unit 14 is operated, each drive motor 26 is operated according to the operation command value, and its rotation is controlled via each flexible shaft 25. The corner is worm 23,
23' and the worm wheel 24.24' moves up and down or rotates left and right, and the multi-degree-of-freedom arm 1 approaches the object to be inspected 18 while performing various bending movements, and the tip of the multi-degree-of-freedom arm 1 approaches the object to be inspected 18. A visual device 2 provided at the inspection site observes and inspects the object 18 to be inspected. During such a bending motion of the multi-degree-of-freedom arm 1, the fixed point 29 of the flexible shaft 25
Although the required length between the torque limiter 32 and the torque limiter 32 changes,
The spline shaft 27a of the slide joint 27 changes depending on the change in the required length of the flexible shaft 25.
Since the flexible shaft 25 slides inside, the expansion and contraction of the flexible shaft 25 is absorbed, and the flexible shaft 25 can perform the rotation transmission action without any hindrance. Further, when the visual device w2 reaches the target position, the multi-degree-of-freedom arm 1 is stopped and the visual device 2 is operated. In this case, even if a distant object is observed in close-up by the television camera 30 with an electric zoom lens that constitutes the visual device 2, in this example, when the multi-degree-of-freedom arm 1 stops driving, the worm 23 (23
) and the cell clock characteristics of the worm wheel 24 (24') work to lock the brakes on each arm member 21, 22, so camera position setting control is performed with high precision and blurring of the image is prevented. .

Furthermore, if the multi-degree-of-freedom arm 1 comes into contact with some kind of obstacle during the bending motion of the multi-degree-of-freedom arm 1, the load during rotation of the flexible shaft 25 increases and the torque limiter 32 slips. 25 is prevented from being subjected to excessive torque from the drive motor 26, the contact direction is displayed on the CRT 35 via the contact sensor 36, and if the degree of contact is large, the operation of the motor 26 is controlled via the control device 1o. Temporarily stopping to prevent trouble from occurring in the drive system of the multi-degree-of-freedom arm 1.

Therefore, according to this embodiment, the following effects are achieved.

There is no need to provide the drive motor 26 inside the multi-degree-of-freedom arm l, and the internal structure is a worm, a worm wheel,
Since it consists of a simple drive mechanism such as a flexible shaft, the multi-degree-of-freedom arm 1 can be made smaller (smaller in diameter) and lighter, and the device can be easily disassembled and reassembled at the work site, so it can be easily installed in narrow passages. Even if the inspection room 16 is in a radioactively contaminated atmosphere, the multi-degree-of-freedom arm 1 can be carried in and out of the building at a distance from the inspection hole 17. The multi-degree-of-freedom arm 1 can be easily operated while avoiding piping, tanks, etc. in the inspection room 16 space.

In addition, since the arm drive mechanism within the multi-degree-of-freedom arm 1 does not require much installation space, the cable 30 of the visual device 2, etc.
It is easier to pass the wire through, and it is easier to maintain and has a longer lifespan than when wires or chains are used for rotation transmission.

Furthermore, since the arm drive mechanism uses a gear with a cell clock function using the worm 23 (23') and the worm wheel 24 (24'), there is no need to perform position holding control when the drive end is stopped, and the control is simple. Since there is no slight movement in the arm, inspection and observation of the visual system @2 can be carried out without any trouble, and even if a problem occurs in the drive mechanism (inoperation, power outage), the arm position is maintained, which is effective for ensuring safety. Furthermore, the torsion of the flexible shaft 25 itself is reduced to 1 of the dead force of the gear, which improves the accuracy of arm movement. The displacement of the arm can be confirmed by detecting the
As a result, there is no need to install a potentiometer or the like inside the arm, making cleaning, maintenance, etc. easier, and furthermore, the arm itself can be significantly reduced in size and weight. In addition, since the flexible shaft 25 and the drive motor 26 are connected by a slide joint with a spline structure, various effects such as being able to absorb expansion and contraction during the bending movement of the flexible shaft 25 and ensuring smooth arm movement are achieved. It can be played.

[Effects of the Invention] As described above, according to the present invention, the entire device can be made smaller and lighter, and it can be easily disassembled and reassembled at the work site, making it possible to transport it to narrow spaces. Remote operation and positioning control can be performed with high precision in a simple structure.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the usage state showing one embodiment of the present invention, and FIG.
The figure is a partially omitted side view showing the main parts of the above embodiment, Fig. 3 is a schematic configuration diagram showing the main parts of the above embodiment, and Fig. 4 is a sectional view showing the internal structure at section A in Fig. 2. 5 is a sectional view taken along the line x-x in FIG. 4, FIG. 6 is a sectional view showing the internal structure at section B in FIG. 2, FIG. The figure is a partially cutaway sectional view showing the connection structure of the flexible shaft and the drive motor in the above embodiment, FIG. 9 is a schematic diagram showing a method of controlling the drive mechanism of the above embodiment, and FIG. 10 is a guide used in the above embodiment. FIG. 11 is a cross-sectional view showing how the tube is attached, and is a system diagram showing a method of controlling the entire apparatus of the above embodiment. 1...Multi-degree-of-freedom arm, 2...Visual device, 6...
Drive unit, 9... Monitor device (monitoring unit),
14... Remote control unit, 21... Vertical swinging arm member, 22... Lateral swinging arm member, 23, 23'...
Warm. 24.24'... Worm wheel, 25... Flexible shaft, 26... Drive motor, 27...
Slide joint, 32...Torque limiter.

Claims (1)

[Scope of Claims] 1. A remote control device in which a visual device for inspecting and observing an object to be inspected is attached to the tip of a multi-degree-of-freedom arm, and remote control is performed while monitoring the multi-degree-of-freedom arm with a monitor device. In the multi-degree-of-freedom arm-type inspection device of the operation method, the multi-degree-of-freedom arm alternately connects a plurality of vertical swinging arm members and horizontal swinging arm members so as to be rotatable in the vertical direction or the horizontal direction. The vertically swinging arm member and the left and right swinging arm member each include a joint drive consisting of a worm and a worm wheel for vertically moving or horizontally rotating each arm member. A mechanism is provided, a plurality of drive motors for driving the joint drive mechanism are housed in a drive unit formed separately from the multi-degree-of-freedom arm, and the horizontal swing arm member and the vertical swing arm member are A flexible shaft that transmits rotational force to each of the joint drive mechanisms described above is passed through the interior, and one end of each of the flexible shafts is connected to the worm of each of the joint drive mechanisms described above, and the other end is connected to the drive unit. A multi-degree-of-freedom arm-type inspection device, characterized in that the multi-degree-of-freedom arm is detachably connected to the housed drive motor via a slide joint, and the multi-degree-of-freedom arm is detachably fixed to the drive unit. 2. The multi-degree-of-freedom arm-shaped inspection device according to claim 1, wherein the worm wheel of the joint drive mechanism is formed in a fan shape. 3. In claim 1 or 2, the drive motor that drives the joint drive mechanism has a torque limiter on its output shaft that blocks excessive load torque from being applied to the flexible shaft. A multi-degree-of-freedom arm-shaped inspection device.