JPH07109565B2 - Moving body position control method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a position control method for a moving body that is connected to a turning fulcrum by a rope and that turns around a turning fulcrum while generating tension in the rope. It is a thing.

[Conventional technology]

For example, in the construction of a huge suspension bridge such as the Akashi Kaikyo Bridge, the installation caisson method is adopted as the construction method of the main tower foundation. This method is a method in which a hollow cylindrical steel caisson is installed on a supporting ground in the sea and the concrete is filled into the caisson in multiple steps.

According to the above-mentioned construction method, the underwater concrete placed in the caisson has a multi-layered structure. However, when concrete is poured, impurities and the like contained in the concrete are exposed to the surface, so-called green cut occurs. In addition, mud that floats up in water may be deposited on the surface of concrete. Therefore, since these are not removed, when the next layer is cast, there is a disadvantage that a discontinuity of strength is generated between layers of concrete, that is, at the joint.

In order to eliminate such inconvenience, it is necessary to clean the underwater seam and collect the removed green cut and the like. Since such work is performed in deep water, it cannot be manually performed, and a machine is used.

Conventional underwater work machines that can be applied to such work include a rubble leveling robot equipped with a scaled insect type moving mechanism consisting of multiple slide legs, a sand removal robot having a track type moving mechanism, an underwater bulldozer, etc. Are known.

[Problems to be Solved by the Invention]

Conventional underwater work machines do not need to perform position control because they cannot perform autonomous movement.
For this reason, it was difficult to travel accurately within the limited range according to the prescribed course. Therefore, the joint seam processing work of the installation caisson construction method of thoroughly cleaning the entire joint seam of a predetermined area on the deep water bottom is not suitable for the conventional underwater working machine.

Therefore, the inventors of the present invention have invented a moving body having an autonomous moving function, which is suitable for work such as underwater in which the moving range is limited, such as the above work.

This moving body is connected to a turning fulcrum rotatably provided in the center of the moving range via a rope, and makes a turning movement around the turning fulcrum while generating tension in the rope. According to this device, since the turning fulcrum also rotates with the turning movement of the moving body, the circumferential position of the moving body can be determined by the rotation angle of the turning fulcrum. However, in reality, if the tension generated in the cord is too large or too small, the turning fulcrum does not rotate smoothly, and the accurate circumferential position of the moving body cannot be determined. was there.

[Means for Solving the Problems]

A position control method for a moving body according to the present invention includes a moving body having a steering function and a self-propelled function, a pillar standing on a moving plane of the moving body, and a turn rotatably provided on an outer periphery of the pillar. A fulcrum, and a rope body that connects the moving body and the turning fulcrum and that sends a control signal to the moving body, and the moving body is defined with the rope body as a radius around the turning fulcrum. While generating a tension on the rope with the turning movement of the moving body when turning on the moving plane, the tension is set to be smaller than an upper limit value capable of smoothly rotating the turning fulcrum. The rudder angle of the moving body is controlled so that the position of the moving body in the circumferential direction is detected from the rotation angle of the turning fulcrum, and the rope is moved to a predetermined length every time the rotation angle reaches a predetermined angle. Try to extend or pull back It is intended.

[Operation] There is a certain relationship between the tension of the rope and the steering angle of the moving body. If the steering angle of the moving body is feedback-controlled based on the detected tension of the rope based on this relationship, the tension can be kept within a predetermined range at all times. As a result, the turning fulcrum can rotate smoothly, and the accurate circumferential position of the moving body can be obtained from the rotation angle. Then, each time the rotation angle reaches a predetermined angle, the rope is extended or pulled back by a predetermined length, so that the moving body moves inward and outward with the support post as the center, as shown in FIGS. 4 (b) and (c). Rotate to
Move in a spiral.

〔Example〕

The present embodiment relates to a cleaning movable body used for the joint processing in the above-mentioned installation caisson method and its control method.

1 and 2 show the inside of a caisson installed on the bottom of the water. In the figure, reference numeral 1 denotes a concrete joint which is driven into the inner bottom portion of the caisson, and is referred to as a moving plane 1 here. The moving plane 1 has a circular shape, and a pillar 2 is provided at the center thereof.
Is erected. A column-shaped swivel fulcrum 4 is rotatably provided on the lower portion of the column 2 near the moving plane 1 via a swiveling roller 3. An angle sensor 5 is provided at the turning fulcrum 4 so that the rotation angle φ of the turning fulcrum 4 with respect to the column 2 can be detected.

Although not shown, the upper end of the column 2 projects above the water, and a turntable equipped with a power source, control equipment and the like is rotatably provided at the upper end thereof. The turntable rotates in the same direction as the turning fulcrum 4 in synchronization with the turning of the turning fulcrum 4.

Next, on the turntable, a feeding device 7 for the rope 6 and a sensor 8 for detecting the amount of the rope 6 fed are provided. The rope body 6 is a cable for sending power and control signals to a mobile body 10 described later. Further, a guide device 9 for the rope 6 is provided on the outer peripheral surface of the turning fulcrum 4.
Then, the rope body 6 fed out from the feeding device 7 is guided right below along the support column 2 and is wound around the guide device 9 of the turning fulcrum 4 to be horizontally pulled out to the outside of the moving plane 1. .

The tip of the rope body 6 is a moving body 10 traveling on the moving plane 1.
It is connected to the. The moving body 10 is a four-wheel drive vehicle that travels by a hydraulic motor. In this moving body 10,
An electric motor is driven by electricity supplied from the outside via the rope 6, and the electric motor drives a hydraulic pump to supply hydraulic oil to a hydraulic motor provided for each wheel.

Further, the front wheels 11 of the moving body 10 have a steering function. That is,
The two front wheels 11, 11 are connected by a tie rod so as to interlock in the same direction, and can be steered left and right at a desired steering angle θ by a hydraulic cylinder (not shown).

Further, a tension sensor for detecting the tension T acting on the cord 6 is provided at the connecting portion between the moving body 10 and the cord 6.
A detection signal from the tension sensor is input to a control unit (not shown) of the moving body 10 to feedback-control the steering angle of the front wheels 11.

Next, a method for controlling the position of the moving body 10 in the above configuration will be described.

As shown in FIG. 2, the position of the moving body 10 is defined as follows.

Radial position ... Length R of the rope body 6 Circumferential position ... Rotation angle φ from the origin of the turning fulcrum 4 Therefore, if the length R of the rope body 6 is changed according to the turning angle of the turning fulcrum 4, The position of the moving body 10 in the radial direction can be changed. In addition, when the moving body 10 is self-propelled, a tension T is generated in the rope body 6, and the turning fulcrum 4 is rotated in synchronization with the moving body 10 by the circumferential component of the tension T. The rotation angle φ of the turning fulcrum 4 indicating the circumferential position changes.

Here, the tension T of the rope 6 regarding the positioning in the circumferential direction must be equal to or less than the allowable value T _a due to the physical constraint of the rope 6. Further, when the cord 6 is loosened, the radial position cannot be indexed, so the tension T is set to T _L = 0 or more. And
The tension T of the rope 6 is caused by the component of the circumferential direction of the rope 6 to turn the fulcrum 4
Must not exceed the upper limit value T _U that allows smooth rotation. Therefore, the proper range of the tension T that the rotation of the turning fulcrum 4 and the turning movement of the moving body 10 can correspond to each other without the rope 6 loosening is as follows.

T _L <T <T _U <T _a (1) Method of controlling rudder angle θ In order to keep the tension T of the rope 6 within the appropriate range described above, the rudder angle θ of the moving body 10 should be adjusted according to the tension T. You can control it.

In FIG. 2, θ _{T = 0} is a steering angle that gives the tension _{T = 0} of the rope 6, and when the wheel base is L, the following formula is obtained, which changes depending on the radius R. At this time, the center line of the front wheel 11 is perpendicular to the radial direction.

The reference tension T _O is a suitable value between T _L and T _U. The reference rudder angle θ _O is a rudder angle that gives the reference tension T _O to the rope 6.

In FIG. 2, in order to apply the reference tension T _O to the cord 6, From the position, the front wheel 11 must be cut to the minus side. If the angle of this minus increment is α (steering),
The reference steering angle θ _O is expressed by the following equation.

Here, the control procedure of the steering angle θ according to the tension T will be described with reference to FIG.

At the sampling cycle t, the tension T of the cord 6 is detected by the tension sensor.

If the tension T exceeds the allowable tension T _a of the cord 6, the movement is stopped.

If T _L <T <T _U , the angle θ _t-1 at the time of sampling is maintained.

If T <T _L , a minus increment of Δ is given to the angle θ _t-1 at the time of sampling. This increases the tension T.

If T> T _U , a plus increment of Δ is given to the angle θ _t-1 at the time of sampling. This reduces the tension T.

The actual steering angle θ is controlled by moving the steering lever with the hydraulic cylinder and feeding back the actual stroke with the attached stroke sensor.

(2) Radial position control method The movement pattern of the moving body 10 is the steady turn of FIG.
3 of the outer turning shown in FIG. 4 (b) and the inner turning shown in FIG. 4 (c).
It is a kind.

The steady turn is a movement pattern whose position in the radial direction is constant and does not require control.

In position control in outward and inward turning, the angle φ of the turning fulcrum 4 is detected by the angle sensor 5, and the feeding amount of the cord 6 is controlled by the cord feeding device 7 and the sensor 8 accordingly.

Assuming that the radius change per rotation of the moving body 10 is p, the feeding amount Δp of the rope 6 per unit rotation angle is given by the following equation.

According to the above equation, it is necessary to continuously change the amount of the rope 6 to be fed out, and when the working radius R is large, the rotation speed controllable range of the electric motor is usually exceeded, so that it is realistic. Not. It is possible if the ratio of the minimum work radius to the maximum work radius is equal to or less than the maximum / minimum rotational speed ratio that the motor can control.

Therefore, as a practical control method, one round is divided into n equal parts,
It suffices to apply a constant amount of feed p '= p / n for each angle of 2π / n. In this way, it is not necessary to change the feed for each time (radius), and the control becomes easy. In this case, the movement pattern has a saw-tooth shape, but when viewed macroscopically, there is usually no problem in the work.

Although the one embodiment described above relates to the seam treatment of underwater concrete, the present invention is widely applicable not only to underwater work but also to work in a generally limited work range.

〔The invention's effect〕

In the position control method for a moving body according to the present invention, in the position control of the moving body which is connected to the turning fulcrum by the rope and turns, the tension of the rope and the steering angle of the moving body have a certain relationship. Paying attention to, the steering angle is feedback-controlled based on the detected tension so that the tension is always kept within a certain range. Therefore, the rotation of the swing fulcrum interlocking with the moving body becomes smooth around the support column, and the accurate circumferential position of the moving body can be obtained without applying excessive tension to the rope as the control signal cable to damage it. There is an effect.

Further, since the rope is extended or pulled back by a predetermined length whenever the rotation angle of the moving body reaches a predetermined angle, as shown in FIGS. It can be smoothly rotated inward and outward with the center as a center, and can be spirally moved. By this moving body, it is possible to efficiently and safely perform the cleaning process in water of the joint of the installation caisson method.

[Brief description of drawings]

FIG. 1 is a schematic front view showing an embodiment of the present invention, and FIG.
The figure is also a schematic plan view, FIG. 3 is a flow chart showing the procedure of the steering angle control in this embodiment, and FIGS. 4 (a), 4 (b) and 4 (c) are respectively of the moving body in this embodiment. It is a figure which shows a movement pattern. 1 ... moving plane, 4 ... turning fulcrum, 6 ... cord, 10 ... moving body, T ... tension, θ ... steering angle.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Kazuo Akiyama 1-2-1 Akiba, Niigata City, Niigata Prefecture Inside the Niigata Iron Works Oyama Plant (72) Inventor Hisao Kuroda 2 Tsutoshima-dori, Miyakojima-ku, Osaka-shi, Osaka Prefecture 1-7-902 (72) Inventor Kunioki Yamada 2957 Ota Kubo, Urawa-shi, Saitama 12 (56) References JP-A-62-297908 (JP, A) JP-A-63-302985 (JP, A)

Claims (1)

[Claims] 1. A mobile body having a steering function and a self-propelled function,
A pillar that is erected on the moving plane of the moving body, a swing fulcrum that is rotatably provided on the outer periphery of the pillar, and a cable that connects the moving body and the swing fulcrum and sends a control signal to the moving body. And a tension is applied to the rope with the turning movement of the moving body when the moving body is turned on the moving plane with the turning body as a radius around the turning fulcrum. The steering angle of the moving body is controlled so that the tension becomes smaller than an upper limit value for smoothly rotating the turning fulcrum, and the tension in the circumferential direction of the moving body is changed from the rotation angle of the turning fulcrum. A position control method for a moving body, which detects a position, and extends or retracts the cord for a predetermined length whenever the rotation angle reaches a predetermined angle.