JP2001096478A - Rope type bending mechanism, manipulator equipped with rope type bending mechanism, bending type in-liquid propelling body, and endscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rope type bending motion mechanism and various practical devices possible to operate at high speed without using heat when a long narrow body such as a manipulator or an in-liquid propelling body and the like is used. SOLUTION: Two elastic bars with electromagnets which are distributed and attached are placed in parallel, a part of the elastic bars is fixed by an electromagnetic suction, and a active slipping is caused by an electromagnetic reaction at a position apart from the fixed point to realize the bending. The parts for fixing and active slipping are shifted along a fixed direction to realize the spreading of the bending wave.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a manipulator,
The present invention relates to a cord-shaped bending mechanism used for a long body having a bending mechanism such as a bent-shaped liquid propelling body and an endoscope, and a manipulator, a liquid propelling body, and an endoscope provided with such a cord-shaped bending mechanism. .

[0002]

2. Description of the Related Art A large multi-degree-of-freedom manipulator such as an articulated system or a wire-pulley system in which a rotary actuator such as an electric motor is attached to a joint is smaller than an electric motor as a small multi-degree-of-freedom manipulator. A large number of actuators using a shape memory alloy having a high output / weight ratio, which is easy to use, are used. In the shape memory alloy actuator, a shape memory alloy such as a Ti—Ni alloy is mainly in the form of a wire, and is stretched in advance to give a strain. This movement utilizes the function that when a wire-shaped shape memory alloy is energized and heat is generated by electric resistance, it contracts to the state before the wire is stretched by the shape memory effect, and when the power is stopped and cooled, the wire is stretched again. It is. In order to increase the amount of shrinkage, many wires have a coil shape.
-227223, JP-A-10-21623
For example, a long object bending mechanism and the like are disclosed in Japanese Patent Application Laid-Open No. H8-208.

Generally, a screw propeller is widely used as an underwater propulsion mechanism. However, rotating at a high speed poses a danger to a creature in the water and causes cavitation when the water pressure becomes lower than the saturated water vapor pressure of water. There is a problem. Also, screw propellers are not suitable for moving mechanisms in highly viscous liquids.

A mechanism that simulates the bending motion of a fish or the like is effective as a new underwater bending propulsion mechanism that compensates for the drawbacks of a screw propeller. For example, a propulsion mechanism that obtains thrust by bending fin-shaped fins of a dolphin is used. Mechanism (Japanese Unexamined Patent Publication
No. 126720) has been proposed.

[0005]

However, the movement speed and response of the conventional shape memory alloy actuator strongly depend on the heating-cooling speed, and it has been difficult to perform a high-speed bending operation. In addition, since a temperature difference must be generated, a cooling device must be installed in an environment where cooling is difficult, which is large and complicated. Further, when applied to medical devices such as endoscopes, there is a problem that the shape memory alloy actuator heated to high temperature must be shielded from living tissue.

[0006] Further, for a bent-type propulsion mechanism as an underwater propulsion mechanism replacing the screw propeller, an active bending mechanism is required for its driving. When a shape memory alloy actuator is used in a bent-type underwater propulsion mechanism, the cooling performance of the shape memory alloy actuator is improved by water in the external environment. There is a problem that must be.

[0007] The present invention has been made in consideration of the above problems and problems, and
A small bending mechanism that can operate at high speed, does not use heat, and is excellent in responsiveness, controllability, and economic efficiency, and a manipulator, bending type liquid propulsion body, endoscope,
Another object of the present invention is to provide a long body used for various other purposes.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention focuses on the operating principle of the flagellar movement of eukaryotes such as sperm and the movement of cilia such as paramecium. By recreating some of the functions of motor proteins called dynein distributed in several microtubules and their distribution with two elastic rods and their associated electromagnets, a cord-like bend like never before This has led to the invention of the mechanism.

That is, two elastic rods are arranged in parallel,
A part between the elastic rods is fixed by the attractive force of the electromagnet,
By generating active sliding at a part away from it by the repulsive force of an electromagnet or the like, we succeeded in realizing a bending motion mechanism with good controllability and responsiveness. In addition, the "active slip" here means that the electromagnet rows attached to the two opposing elastic rods are in contact via the flexible plate, and the elastic rods actively move in the opposite axial direction. It is as if the elastic rod is actively sliding.

From the viewpoint of responsiveness and controllability, it is preferable to use an electromagnet. However, as long as suction and repulsion are possible, not only electromagnets but also piezoelectric actuators and electrostatic actuators can be used.

[0011] The propagation of the bend of the cord-like bending mechanism of the present invention in the distal direction is performed by moving the electromagnet attached to the two elastic rods toward the distal direction by fixing by the attraction force and actively sliding by the repulsive force. It is realized by. However, since the fixing and sliding functions disappear at the distal end, in order to perform continuous bending propagation, the fixing and sliding functions are generated as needed on the base side and are moved toward the distal end.

Although the cord-shaped bending mechanism of the present invention is basically formed in a cylindrical shape, any other shape than a cylindrical body may be used as long as the arrangement of the flexible rod and the electromagnet is maintained and the bending motion is possible. To support the electromagnet and generate sliding motion, wrap it with an anisotropic stretchable fabric that stretches without resistance in the axial direction and does not stretch in the circumferential direction to achieve reliable and flexible bending motion. Can be.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the bending principle of the cord-shaped bending mechanism according to the present invention, using an electromagnet as an example.

As shown in the figure, two elastic rods 12 with distributed electromagnets 10 are arranged facing each other. The elastic rod 12 needs an elastic force to return to a linear shape even when bent, but if the elastic force is too large, a large load is applied to the occurrence of active sliding by the electromagnet. Further, the shape of the elastic rod is preferably a shape suitable for joining with an electromagnet. Here, a vinyl chloride plate rod was used.

The elastic rod 12 has a fixing region 14 for fixing the facing electromagnets with different polarities, a passive region 16 in which no force acts without energizing, and a facing region where the facing electromagnets have the same polarity to generate a repulsive force. A bend is formed by the slip region 18 that generates a smooth slip. The electromagnet must not only have a magnetic force that exceeds the elastic force of the elastic rod, but also generate a magnetic force that can maintain the bending motion even when an external load is applied to the cord-shaped bending mechanism.

Immediately after bending occurs due to slippage, the body is fixed at a different polarity to maintain its shape. Further, by propagating the polarity of the electromagnet at a constant speed in the distal direction, each region can be moved at a constant speed in the distal direction, and propagated as a bending wave in the distal direction.

Four sets of three areas, a fixed area, a passive area, and a sliding area, are prepared. For the four sliding areas from the base side, the direction of the sliding is such that the left elastic rod slides the right elastic rod toward the distal end. The direction in which the left elastic bar slides toward the distal end side of the right elastic bar is alternately changed. The generation of the continuous bending motion of the waveform is realized by moving all the regions toward the distal end at a constant speed and generating the respective regions as needed on the base side. Thus, a sine wave shape having one wave number was realized.

Further, by increasing the number of elastic rods from two to three and disposing the elastic rods at the vertices of an equilateral triangle, it is possible to realize a three-dimensional motion capable of forming a spiral shape. In this case, two rows of electromagnets attached to one elastic rod are prepared so as to face the adjacent elastic rods.

FIG. 2 shows the internal structure of the cord-shaped bending mechanism of the present invention. The electromagnet 20 is supported by an elastic beam 22 made of vinyl chloride corresponding to the elastic rod of the bending principle shown in FIG. 1. A flexible sheet 24 is provided between facing electromagnets to prevent interference between the electromagnets. Further, in order to make the mechanism have a cylindrical shape, a semicircular aluminum shell 26 is provided outside each of the electromagnets. The total length of the cord-shaped bending mechanism is 30 cm and the diameter is 3 cm. 30 electromagnets are arranged at 1 cm intervals per elastic beam.
A total of 60 electromagnets for two elastic rods are used.

The shape of the iron core of the electromagnet preferably used in the present invention is "U-shaped" as shown in FIG. 3, and coils are wound around both ends, respectively. The iron core is formed by laminating five electromagnetic soft iron plates (JIS C2504) having a thickness of 0.8 mm, and the winding is a polyurethane-fused copper wire having a diameter of 0.1 mm. The iron core shape of the electromagnet can be cylindrical or the like, but if it is "U-shaped", since the bending mechanism does not torsion at the time of rebound, it should be "U-shaped". Desirable for stable bending.

In order to keep the distance between the electromagnet rows facing each other constant, the electromagnetic force must always be in contact with the flexible sheet. Therefore, the flexible sheet preferably has a small friction with the electromagnet, and the PTFE sheet is particularly preferable. Further, as a method of supporting the shell attached to the electromagnet, the shell may be wrapped with a material that extends without resistance in the long axis direction and hardly expands in the circumferential direction. In the present invention, as shown in FIG. Let it wrap. In addition, a medical bandage is suitable as the rubber-filled gauze. As a result, a reliable and flexible bending motion was realized, and a continuous sinusoidal bending waveform having an amplitude of 1 cm and a frequency of 6.1 Hz was realized.

The excitation of the electromagnet for realizing the bending motion is shown in FIG.
As shown in (1), a DC current from a power supply 56 is switched by using a pulse output board 52 of 128 channels controlled by a personal computer 50 and a driver 54 constituted by a relay circuit.

As a control method, the behavior of each electromagnet is calculated in advance to generate a desired bending motion, and an excitation sequence with respect to time is prepared in advance as binary data. Based on this, the signal is continuously output from the pulse output board. This binary data divides one cycle of the bending motion at appropriate time intervals as shown in the example of FIG.
The excitation information of all electromagnets is described for each division time. Allocate 2 bits for one electromagnet and set 01 to N
The poles, 10 are S poles, and 00 is no excitation.

By providing the cord-shaped bending mechanism on the arm portion of the manipulator, a manipulator having good controllability and responsiveness was obtained. In addition, by providing the cord-shaped bending mechanism in the propulsion drive unit of the bent-type in-liquid propelling body, an in-liquid propelling body with good controllability and responsiveness was obtained.
Furthermore, by using this cord-shaped bending mechanism as an insertion portion for actively bending an endoscope, an endoscope with good controllability and responsiveness can be obtained. In addition, the present invention can be applied to various devices that require two-dimensional bending, and can be applied to various devices such as medical devices by preparing three rows of electromagnets.

[0025]

As described above, according to the present invention,
Extremely good controllability and responsiveness can be realized with a simple mechanism by the attraction and repulsion of the electromagnet, and this bending motion mechanism is used in manipulators, bent submerged propulsion mechanisms, endoscopes, etc. As a result, compared to conventional manipulators and the like, it is possible to perform a rope bending movement such as a complex shape such as a sine wave shape and a helical shape, which is higher in performance than the conventional one, and more economically. Also, an excellent bending mechanism can be created, and various practical devices using the bending mechanism have been achieved.

[Brief description of the drawings]

FIG. 1 shows the bending principle of the cord-shaped bending mechanism of the present invention.

FIG. 2 is an internal configuration of the cord-shaped bending mechanism of the present invention.

FIG. 3 shows a configuration of an electromagnet used in the cord-shaped bending mechanism of the present invention.

FIG. 4 is a rubber-filled gauze enclosing the cord-shaped bending mechanism of the present invention.

FIG. 5 is a control and drive block diagram of the cord-shaped bending mechanism of the present invention.

FIG. 6 is an example of sequence binary data of electromagnet excitation of the cord-shaped bending mechanism of the present invention.

FIG. 7 is an example of a manipulator provided with the cord-shaped bending mechanism of the present invention.

FIG. 8 is an example of a bent submerged propulsion mechanism provided with the cord-shaped bending mechanism of the present invention.

FIG. 9 is an example of an endoscope provided with the cord-shaped bending mechanism of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Electromagnet 12 ... Flexible rod 14 ... Fixed area 16 ... Passive area 18 ... Sliding area 20 ... Electromagnet 22 ... Elastic beam 24 ... Teflon sheet 26 ... Shell 30 ... Iron core (electromagnetic soft iron plate) 32 ... Winding wire 40 ... Flexible sheet (Rubber-filled gauze) 50 personal computer 52 pulse output board 54 driver 56 power supply 70 manipulator 80 bending-type submerged propulsion mechanism 90 endoscope

 ──────────────────────────────────────────────────続 き Continuing from the front page (71) Applicant 599153301 Kozo Furihata 3-15-1, Tsuneda, Ueda-shi, Nagano Shinshu University Graduate School of Engineering (72) Inventor Shunichi Kobayashi 3--15, Tsuneda, Ueda-shi, Nagano No. 1 Shinshu University Faculty of Textile Science and Technology Department of Functional Machinery (72) Inventor Hirohisa Morikawa 3- 15-1 Tsuneda, Ueda City, Nagano Prefecture Shinshu University Textile Department of Functional Machinery Department of Functional Machinery 3-15-1 Shinshu University Graduate School of Engineering F-term (Reference) 3F060 BA03 BA04 GA11 4C061 AA00 BB00 CC00 DD03 FF25 FF29 FF32 HH42

Claims (8)

[Claims] 1. A method for fixing a part between two elastic rods,
A cord-shaped bending mechanism that generates active sliding in a part away from it and realizes bending. 2. The cord-shaped bending mechanism according to claim 1, wherein the bending between the elastic rods is realized by using an active force caused by a fixing force and a repulsive force of the electromagnet. 3. The cable-like bending mechanism according to claim 2, wherein the bending wave is propagated by moving the electromagnet in a fixed direction by fixing the electromagnet by the attractive force and by moving the active slip by the repulsive force in a predetermined direction. 4. The cord-shaped bending mechanism according to claim 2 or 3, having a cylindrical cross-sectional shape wrapped in an anisotropic cloth extending in an axial direction but not in a circumferential direction. 5. An electromagnet using a U-shaped iron core in which electromagnetic soft iron plates are laminated is distributed and arranged on two elastic beams, respectively.
A cord-shaped bending mechanism in which a soft sheet is arranged between two elastic beams. 6. A manipulator provided with the cord-shaped bending mechanism according to claim 1. 7. A bent in-liquid propelling body provided with the cord-shaped bending mechanism according to claim 1. 8. An endoscope provided with the cord-shaped bending mechanism according to claim 1.