JPH03111182A - Three dimensional motion mechanism - Google Patents

Abstract

PURPOSE:To obtain a large output on the whole even in case of the output of an individual actuator being small by composing it so as to give three degrees of freedom by the three telescopic actuators which are arranged so as to make a parallel or small angle one another. CONSTITUTION:When three telescopic actuators 6 are respectively worked and the lengths thereof are changed, the three dimensional position of a free end frame (leg frame) 10 varies. In that case, the free end frame 10 is fitted to a support rod 12 and only the sliding in the axial direction is made to be allowed, so the posture is univocally determined. Consequently, a wall face suction unit 5 fitted to the free end frame 10 is positioned at the desired position inside a three dimensional space by adequately setting the lengths of the three telescopic actuators 6.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a three-dimensional movement mechanism that can be positioned arbitrarily in three-dimensional space. This invention relates to a three-dimensional movement mechanism suitable for the arm mechanism of a manipulator to be installed.

(Prior Art) When inspecting or cleaning the wall of a large structure such as a building or an oil tank, a wall moving device that can be moved along the wall is used. There are various types of such wall surface moving devices, and several wall surface suction moving machines that move while adhering to a wall surface have been proposed so far. The main types are those that use multiple wall adsorption units that perform negative pressure adsorption or magnetic adsorption, and move by sliding the body while repeating adsorption and desorption alternately, or adsorption to the wall by rotating adsorption wheels. Examples include things that move while moving.

(Problem to be Solved by the Invention) However, although such wall suction moving machines can move on flat, vertical, cylindrical, or spherical walls, they cannot move across a part of the corner of a building. It is not possible to achieve various types of wall movement, such as movement, movement on walls with large protrusions, or movement from a wall to a ceiling.

In order to be able to deal with such a variety of wall surfaces, it is conceivable to create a walking robot with multiple sets of leg mechanisms attached to its body. In that case, the leg mechanism would need to be able to move in three dimensions. That is, it is necessary to provide at least three degrees of freedom.

An example of such a movement mechanism having three degrees of freedom is a three-axis orthogonal coordinate type mechanism using three sets of orthogonal actuators. However, in the case of a wall-walking robot whose basic movement is to climb vertically up a wall, a large load is applied in the direction of gravity. It is necessary to particularly increase the output of the Furthermore, depending on the posture, a large load is also applied to other actuators, so the outputs of those actuators must also be increased. Therefore, each actuator becomes large in size, and the leg mechanism itself becomes extremely heavy.

There are also articulated three-degree-of-freedom movement mechanisms, but when such mechanisms are used in the leg mechanisms of wall-walking robots, it is necessary to generate large torques at each joint arranged in series. . Therefore, the weight of the leg mechanism also increases.

In this way, since the wall-walking robot basically moves vertically up the wall, it is necessary to reduce its own weight as much as possible and increase its expansion force. For this reason, conventional three-degree-of-freedom movement mechanisms, ie, three-dimensional movement mechanisms, have low feasibility as leg mechanisms for wall-walking robots.

The present invention has been made in view of these circumstances, and its purpose is to obtain a three-dimensional movement mechanism suitable for a leg mechanism of a wall-walking robot.

That is, an object of the present invention is to obtain a three-dimensional movement mechanism that is lightweight and can generate high output.

(Means for Solving the Problems) In order to achieve this object, the present invention uses a parallel link system that uses three telescopic actuators in parallel.
It is designed to constitute a dimensional movement mechanism. The three telescopic actuators are arranged parallel to each other or at a small angle. The base end thereof is rotatably connected to three different points on the base body, and the distal end thereof is rotatably connected to three different points on the free end frame. The free end frame is fitted onto a support rod that is connected to the base body via a universal joint, and is supported so that it cannot rotate about its axis but is slidable in the axial direction. An effector unit such as a wall suction unit is attached to the free end frame.

(Function) With this configuration, when the three actuators are actuated and their lengths are changed, the three-dimensional position of the free end frame is changed. In that case, the free end frame is fitted into the support rod and is allowed to slide only in the axial direction, so its attitude is uniquely determined. Therefore, by appropriately setting the lengths of the three actuators, the effector unit attached to the free end frame can be positioned at a desired position in three-dimensional space.

In that case, the three actuators are arranged along the direction of gravity as much as possible in the normal motion posture. In this way, the load acting on the movement mechanism will be shared almost equally by the three actuators. Moreover, the bending moment applied to the kinematic mechanism is supported by the support rod in which the free end frame is slidably fitted. Therefore, each actuator can have a small output while providing a sufficient degree of freedom of movement, and the weight of the entire movement mechanism can be reduced.

(Example) Hereinafter, the present invention will be explained in detail using the drawings.

In the figure, Figs. 1 and 2 are a schematic front view and a side view showing an embodiment of a wall walking robot using the three-dimensional movement mechanism according to the present invention as a leg mechanism, and Figs. 3 and 4 are a schematic front view and a side view of the robot's legs. FIG. 3 is a perspective view and a vertical side view of the mechanism.

As shown in FIG. 1.2, this wall-walking robot 1 consists of a body 2 as a base and four sets of leg mechanisms 33 attached to the body 2. At the tip of each leg mechanism 3, a wall suction unit 5, which is an effector unit for suctioning the wall surface 4, is attached.

As is clear from FIG. 3.4, the leg mechanism 3 comprises three telescopic actuators 6.6.6. Each actuator 6 is of a ball screw type driven by a motor 7, and its length can be changed independently. The base ends of these three actuators 6.6.6 are rotatably connected to the body 2 via ball joints 8 or universal joints at three points that are not on a straight line of the body 2, respectively. Further, its distal end is rotatably connected to the free end frame, that is, the leg frame 10, via ball joints 9 or universal joints at three points that are not on the - straight line. Moreover, these actuators 6.6.6
are arranged parallel to each other or at a small angle.

A spline shaft 11 is fixed to the leg frame 10. On the other hand, the base end of a support rod 12 is rotatably supported by the body 2 via a universal joint 13. The support rod 12 and the spline shaft 11 of the leg frame 10 are spline-fitted. In this way, the leg frame 10 is supported so as to be unrotatable about the axis of the support rod 12 but slidable in the axial direction.

The wall suction unit 5 includes a support arm 14 and a suction cup 15 attached to the tip thereof. The suction cup 15 is one that adsorbs to the wall surface 4 by magnetic force or negative pressure.
As shown in FIG. 5, it is supported by a cap-shaped supporting force generating member 14a provided at the tip of the arm 14 via an elastic body 16 such as rubber. A friction member 14b made of hard rubber or the like is attached to the periphery of the supporting force generating member 14a, and when the suction cup 15 is attracted to the wall surface 4 and a shearing force is applied to the wall surface 4, the friction member 14b is attached. The shearing force is supported by the friction member 14b, which is abrasive and has a large frictional force, and only the force that peels it off acts on the suction cup 15.

On the other hand, the base end of the support arm 14 is rotatably connected via a ball joint 18 to the base end of a V-arm 17 having bifurcated arm portions 17a, 17a. Between the support arm 14 and the V-arm 17 are coil springs 1.4. s is provided,
The support arm 14 faces in a fixed direction with respect to the V-arm 17 unless an external force is applied. The V-arm 17 is rotatably supported at the tip of the leg frame 10 via a universal joint 19.

The universal joint 19 allows two degrees of freedom to rotate around the axis of the proximal end of the arm 17 and around an axis perpendicular to the axis, and the center of rotation is the center of rotation of the ball joint 18. It is made to match.

In this way, the wall suction unit 5 is rotatable with respect to the leg frame 10.

(2) One end of a parallel holding mechanism 20.20 is connected to the tip of the branch arm portions 17a, 17a of the arm 17, respectively.

1. As shown in FIG. 4, the parallel holding mechanism 20 is composed of a flexible duplex-shaped outer cable 21 and an inner cable 22 inserted through the outer cable 21. The outer cable 21 has one end fixed to the tip of the spline shaft 11 of the leg frame 10, curved inside the body 2, and the other end fixed to the surface of the body 2. The inner cable 22 has one end fixed to the tip of the support rod 12, passes through the outer cable 21, and has the other end fixed to the tip of the V-arm 17 of the wall adsorption unit 5. Inside the body 2, an outer cable 21 through which an inch cable 22 is inserted can be freely bent.

In this way, the wall suction unit 5 is connected to the body 2 by two sets of parallel holding mechanisms 20, 20, which are respectively arranged in different planes.

Next, the operation of the leg mechanism 3 configured in this way will be explained.

Figure 6 shows the principle of the basic structure of this leg mechanism 3. It is an explanatory diagram for explanation.

As shown in this figure, it is assumed that the support rod 12 is connected to the body 2 by a universal joint at the origin 0 and extends in the Z-axis direction. Also, 3
The book expansion/contraction actuators 68, 6□, and 63 are rotatably connected to the body 2 at a point Q on the X axis and points R and S on the Y axis, respectively, and are rotatably connected to the body 2 at points A and Y in the xZ plane. It is assumed that they are rotatably connected to the leg frame 10 at points B and C in the Z plane, respectively.

In this state, when the actuator 6I is expanded or contracted to change its length, the leg frame 10 restrained by the remaining actuators 6□, 63 is moved by those actuators 6g, 6. Rotates around the Y axis along with the plane containing . Therefore, the suction cup 15 for the leg frame 10
When mounting, point P also rotates around the Y axis. Further, when one of the actuators 62, 63 is extended and the other is contracted, the leg frame 10 rotates around the X-axis, and the point P also rotates around the X-axis. And three actuators 61.6
When □ and 63 are simultaneously expanded and contracted, the leg frame 10 moves along the axis of the support rod 12, and the point P moves in the Z-axis direction.

During this time, the leg frame 10 is splined to the support rod 12, so that the plane containing each arm of the leg frame 10, ie point A.

The angle formed between the plane including B and C and the support rod 12 is always kept constant. Therefore, the three-dimensional position of point P is uniquely determined.

During this movement, a moment is generated between each arm of the leg frame 10, but all of this moment is supported by the support rod 12, so the actuators 61.6□, 63
No bending moment acts on. If three actuators 6+ and 62.63 are placed at one point, leg frame 1
If the arms could be rotatably connected to each other, the moment generated between the arms could be reduced to zero, but such a connection is mechanically extremely difficult. Therefore, in order to keep the generated internal moment small, the length of each arm of the leg frame 10 is set such that the actuators 6□, 62.
The connecting portions at the ends of the 6s are made as short as possible without mechanically interfering with each other.

In this way, this leg mechanism 3 includes three actuators 6, . 62.63 provides three degrees of freedom, so the suction cup 15 can be moved to any spatial position. And three actuators 6+, 6
2.6s are arranged in parallel or at a small angle, so if you point them in the direction of gravity, the leg mechanism 3
The load applied to these three actuators 6□, 6□
, 63 are supported almost equally. Moreover, the bending moment acting on the leg mechanism 3 is transmitted from the leg frame 10 to the support rod 12, and the bending moment is transmitted to the body 2 at the origin O.
Supported by Therefore, each actuator 61
, 6□, and 63 only need to bear the load in the axial direction, and can be made lightweight with low output.

By the way, according to this leg mechanism 3, the position of the point P in the three-dimensional space is determined as described above, but the posture of the leg frame 10 changes as the position changes. Therefore, if the leg frame 10 is tilted with respect to the Y-Z plane, for example, the suction cup 15, which had been oriented in a certain direction with respect to the Y-Z plane, will be tilted, causing the normal walking movement to become tilted. It becomes a hindrance. Therefore, a spatial parallelism holding mechanism 20 is provided to keep the posture of the suction cup 15 attached to the leg frame 10 always the same as the posture of the torso 2.
has also been introduced.

FIG. 7 is an explanatory diagram for explaining the principle of the spatial parallelism holding mechanism 2o.

As shown in this figure, a support rod 12 is now rotatably supported on the body 2 at a point ○.
It is assumed that a wall suction unit 56 is rotatably supported at a point P on the leg frame 10 which is spline-connected to the leg frame 10. The point of the tip of the support rod 12 on the side away from the body 2 is designated as K, and the point of the leg frame 10 closer to the body 2 is designated as L. The distance between the leg frame 10 and the body 2 can be changed by a telescopic actuator (not shown).

In this state, for example, bring the leg frame 10 close to the body 2,
If the space between points 012 is contracted, the distance between points L will increase. Conversely, if you widen the interval between points 012, L
are approaching each other.

The sum of the amount of change in the interval between points 022 and the amount of change in the interval between points L is always constant.

That is, OP+KL=constant becomes.

Therefore, an outer cable 21 is provided between the point and point M on the body 2, and an inner cable 22 is provided between the point M on the wall suction unit 5 and the point N on the wall suction unit 5.
Stretch. In addition, the point is 0. The distance between M and the distance between points P and N should be equal.

In this case, since the total length of the inner cable 22 is constant, the length of the portion exposed from the outer cable 21 is also constant, and KL + MN=constant.

Therefore, if we initially set OP=MN, the point is 0.
．． The relationship is maintained no matter how the interval between P changes. And since OM= P N , the quadrilateral O
MNP becomes a parallelogram. As a result, the leg frame 10
Even when the wall suction unit 5 rotates around the point O together with the support rod 12 and moves along the axis of the support rod 12, the wall suction unit 5 is always kept parallel to the body 2.

As described above, since the parallel holding mechanism 20 is constituted by the two cables 21 and 22, it is extremely lightweight, occupies a small space, and can operate smoothly.

If there is a possibility that the inner cable 22 may become slack, a spring 23 may be attached to the opposite side of the inner cable 22 from the fixing point N, as shown in FIG. Further, a pair of such parallel holding mechanisms 20 may be provided on both sides of the point P.

As shown in FIG. 3, the leg frame l of the leg mechanism 3
The V-arm 17 of the wall suction unit 5 attached to the body 2 through the universal joint 19 is held by the body 2 by the pair of parallel holding mechanisms 20 and 20 configured in this way.
is connected to. Moreover, those parallel holding mechanisms 20
．． 20 are arranged in different planes. Therefore, even when the leg frame 10 moves three-dimensionally, the V-arm 17
is always kept parallel to the plane of the fuselage 2. In other words, no matter how the leg frame 10 is tilted, ■the arm 1
Ball joint 18 and spring 14s for 7
The suction cup 15, which is urged to always face in the same direction, always faces in the same direction. the result,
When walking on a flat wall surface 4, the suction cup 15 can always face the wall surface 4, allowing smooth and stable walking.

In this case, since the suction cup 15 is attached via the ball joint 18, it is sufficient to keep it substantially parallel to the wall surface 4, and there is no need to require strictness in the parallelism holding mechanism 20. Therefore, there may be some error in the fixing points of the cables 21, 22, etc.

As shown in FIGS. 1 and 2, such a leg mechanism 3
When the walking robot 1 equipped with four sets of
．． 3 vertically, each leg mechanism 3, 3.・・・
・is placed almost in the direction of gravity. Therefore, the three telescopic actuators 6 constituting each leg mechanism 3 are also arranged substantially in the direction of gravity. Then, the patient walks with a crawl gait, a trot gait, or a pace gait.

In the case of a crawling gait, the remaining leg mechanism 3 is returned to its original position while the three silk leg mechanisms 3 are attached to the wall surface 4, and after the leg mechanisms 3 are attached to the wall surface 4, the other leg mechanisms 3 are attached to the wall surface 4. The procedure of returning one set of leg mechanisms 3 is repeated. In that case, the weight of the robot 1 is supported by three sets of leg mechanisms 3 adhering to the wall surface 4. The load applied to each leg mechanism 3 is shared almost equally by the three telescopic actuators 6. Therefore, the robot 1 is always driven by a total of nine actuators 6, and even if the output of each actuator 6 is small, a sufficient output can be obtained as a whole. This results in a drive system with a high output/weight ratio.

Since a large output is obtained by each leg mechanism 3 in this way, it is also possible to take a trot gait or a pace gait in which the two diagonal sets of leg mechanisms 3 return to normal at the same time. In that case, the suction cup 15 of the leg mechanism 3 during return is held parallel to the wall surface 4 as described above, and the suction cup 15 can be returned in a floating state where it is almost in contact with the wall surface 4. This allows efficient walking. be able to. By adopting such a trot gait or pace gait, faster movement becomes possible.

According to such a wall walking robot 1, it is also possible to move on a vertical wall surface 4 having a large protrusion 4a as shown in FIG. When climbing over the protrusion 4a, each leg mechanism 3 may be largely rotated relative to the body 2 to move the body 2 away from the wall surface 4. At this time, the leg mechanism 3 makes a large angle with respect to the direction of gravity, but since high speed is not required for walking in such a state, there is no need to intentionally increase the output of each actuator 6.

Further, as shown in FIG. 9, movement from the vertical wall surface 4 to the ceiling 4b is also possible. In that case, the same figure (A
), move the fuselage 2 a little away from the wall 4,
After adhering the upper set of leg mechanisms 3 to the ceiling 4b,
While tilting the body 2 as shown in B), attach the other two upper leg mechanisms 3 to the ceiling 4b. Then, as shown in FIG. 2C, the remaining two sets of leg mechanisms 3 are suctioned onto the ceiling 4b in order. Thereby, the robot 1 completely transitions from the vertical wall surface 4 to the ceiling 4b.

On the ceiling 4b, the robot 1 walks with its body 2 far away from the ceiling 4b so that each leg mechanism 3 is in the direction of gravity.

During the operation as shown in FIG. 9(A), the suction unit 5
Since the suction cup 15 is held almost parallel to the wall surface 4, when the leg mechanism 3 is suctioned to the ceiling 4b, the suction cup 1
5 will make a large angle with the ceiling 4b,
The suction cup 15 is only biased by a spring 1.4s and is rotatably supported by a ball joint 18, so that the direction of approach to the ceiling 4b can be adjusted and the body 2 can be tilted. By doing so, it is possible to reliably attract the surface of the ceiling 4b that forms a large angle.

Similarly, as shown in FIG.
It is also possible to move across the

In the above embodiment, the parallel holding mechanism 20 is made up of an outer cable 21 and an inner cable 22, but the parallel holding mechanism 20 may be made of a conventionally known parallel link, hydraulic mechanism, etc. You can also use something. However, for the leg mechanism 3 of a robot, it is desirable to use a mechanism such as the above embodiment, which is lightweight and can be constructed in a compact manner.

Further, in the above embodiment, the spline shaft 11 is integrally provided on the leg frame 10, and the support rod 12 is fitted onto the spline shaft 11. However, the support rod 12 is a spline shaft, and the leg frame 10 may be spline fitted. Furthermore, the leg frame 10 and the support rod 12 may be supported by a simple sliding mechanism consisting of a guide rail, rollers, etc.

Any number of leg mechanisms 3 may be attached to the robot 1 as long as it is two or more. From the point of view of adaptability to the environment, the more legs the better. However, in order to simplify the mechanism, it is better to have fewer legs. Therefore, the number of legs is determined according to the functions required of the robot 1.

Furthermore, the three-dimensional movement mechanism according to the present invention can generate a strong supporting force in the direction of gravity using three telescopic actuators, and also has a degree of freedom of movement in the horizontal direction. By providing a holding mechanism, it is possible to keep the robot parallel to the base at all times, so it can be applied to various things other than the leg mechanism 3 of the wall walking robot 1 as in the above embodiment.

FIG. 11 shows an embodiment in which the present invention is applied to a type of manipulator suspended from the ceiling.

The arm mechanism 31 of this manipulator 30 is It is constructed similarly to the leg mechanism 3 of the embodiment described above.

That is, it includes three telescopic actuators 32 and one support rod 33 arranged in parallel. The base ends of the actuator 32 and the support rod 33 are rotatably connected to a ceiling 34 that is a base body. Also,
A free end frame 35 is slidably supported on the support rod 33, and the tip of the actuator 32 is rotatably connected to the free end frame 35. A gripper 36, which is an effector unit, is rotatably supported by the free end frame 35, and is always kept parallel to the ceiling 34, that is, horizontal, by a parallel holding mechanism 37.

In the manipulator 30 configured in this way,
Since the fingers of the gripper 36 always face downward, it is possible to reliably grip an object 38 placed on a support table or the like.

Since the load is distributed and supported by the three actuators 32, strong supporting force can be obtained.
6. Further, since the arm mechanism 31 can be moved in a three-dimensional space, the object 38 can be moved to an arbitrary position. If it is required to change the orientation of the object 38 in the horizontal plane, the gripper 36 may be given a degree of freedom in rotation about the vertical axis.

Further, FIG. 12 shows an embodiment of a conveying device to which the three-dimensional movement mechanism according to the present invention is applied.

In this transport device 40, a mechanism similar to the leg mechanism 3 or arm mechanism 31 of the above embodiment is used for the support leg 41. The support leg 41 is rotatably supported by a floor 42, which is a base, and a support base 43, which is an effector unit, is attached to the upper end of the support leg 41. The support stand 43 is
It is held parallel to the floor 42 by a parallel holding mechanism 44.

According to such a conveyance device 40, the load of the object 45 placed on the support base 43 is distributed and supported by the three telescopic actuators 7 arranged along the direction of gravity. Therefore, even if the output of each actuator is small, it is possible to support the heavy object 45. By expanding and contracting the actuator, the support base 43 can be moved within the three-dimensional space while maintaining the horizontal state. In this way, the conveying device 40 that can three-dimensionally convey the heavy object 45 is obtained.

The present invention can also be applied to the Stuart platform, etc., when position determination is important and posture determination is less important.

(Effects of the Invention) As is clear from the above description, according to the present invention, three degrees of freedom are provided by three telescopic actuators arranged parallel to each other or at a small angle, so that By arranging each actuator so that it is substantially in the direction of gravity during operation, even if the output of each individual actuator is small, a large output can be obtained as a whole. The free end frame supported by these actuators is slidably fitted to a support rod connected to the base via a universal joint, so that rotation with respect to the support rod is restricted. , not only the three-dimensional position of the effector unit attached to the free end frame is uniquely determined, but also the moment acting on the three-dimensional movement mechanism is supported by its support rod. Therefore, each actuator only needs to share the load in the axial direction, making it possible to make the actuator lighter and smaller.

In this way, a three-dimensional motion mechanism with a high power/weight ratio can be obtained.

9

[Brief explanation of drawings]

FIG. 1 is a schematic front view showing an embodiment of a wall-walking robot using the three-dimensional movement mechanism according to the present invention as a leg mechanism in a state when climbing a vertical wall; FIG. 2 is a side view thereof; 3 is a perspective view showing the leg mechanism of the robot; FIG. 4 is a longitudinal side view of the leg mechanism; FIG. 5 is an enlarged longitudinal side view showing the wall suction unit portion of the leg mechanism; The figure is an explanatory diagram showing the basic structure of the leg mechanism. Figure 7 is an explanatory diagram showing the principle of the parallel holding mechanism used in the leg mechanism. Figure 8 is an explanatory diagram showing the principle of the parallel holding mechanism used in the leg mechanism. Figure 9 is a schematic side view showing the robot moving up a vertical wall with a large protrusion; Figure 9 is a schematic side view showing the robot moving from the vertical wall to the ceiling; is a schematic plan view showing the state when the robot moves across a corner of a building, etc.; FIG. 11 is a schematic side view showing an embodiment in which the three-dimensional movement mechanism according to the present invention is applied to a manipulator; FIG. 12 is a schematic side view showing an embodiment in which the three-dimensional movement mechanism according to the present invention is applied to a conveyance device. ■...Wall walking robot 2...Torso (base body) 3
...Leg mechanism (three-dimensional movement mechanism) 4...Wall surface 5.
...Wall suction unit (effect device unit) 6...Extendable actuator 89...Ball joint O...Leg frame (free end frame) 1...Spline shaft 12...Support rod 3... Universal joint 1 4...Support arm 15...Suction cup 7...V
Arm 18...Pole joint]・9...Universal joint O...Parallel holding mechanism 1...Outer cable 2...Inner cable 0...Manipulator...Arm mechanism (three-dimensional movement mechanism) ) 2... Telescopic actuator 3... Support rod 34... Ceiling (base) 5.
...Free end frame 6...Gripper (effect device unit) 7...Parallel holding mechanism O...Transport device 1...Support leg (three-dimensional movement mechanism) 2...Floor (base body) 3... Support stand (effector unit) 4... Parallel holding mechanism 2 Fig. 1 Fig. 2 Fig. 11 Fig. 12

Claims (3)

[Claims] (1) A support rod whose base end is connected to the base body via a universal joint, and a support rod that is fitted onto the support rod and cannot rotate around its axis, but is supported slidably in the axial direction. a free end frame having a base end rotatably connected to three points on the base that are not on a straight line, and a distal end rotatably connected to three points on the free end frame that are not on a straight line, respectively; , three telescopic actuators arranged parallel to each other or at a small angle, and an effector unit is attached to the free end frame, a three-dimensional movement mechanism. (2) The effector unit is rotatably attached to the free end frame, and the effector unit is attached to the base via two parallel holding mechanisms arranged in different planes. The three-dimensional movement mechanism according to claim 1, wherein the three-dimensional movement mechanism is connected. (3) The parallel holding mechanism is inserted through a flexible outer cable having one end fixed to a point of the free end frame near the base and the other end fixed to the base; The three-dimensional movement mechanism according to claim 2, further comprising: an inner cable fixed to a point of the support rod remote from the base body, and an inner cable whose other end is fixed to the effector unit.