robot

Abstract

The robot joint can be made lighter and less expensive overall, as it can achieve both an inclined and twisted position of the tip relative to the base. [Solution] A robot (S) comprising: a first rolling support member (26) that supports the tip (27) of a first arm (23) so that it can roll and rotate with three degrees of freedom; a second rolling support member (36) that supports the tip (27) of a second arm (33) so that it can roll and rotate with three degrees of freedom; a third rolling support member (46) that supports the tip (27) of a third arm (43) so that it can roll and rotate with three degrees of freedom; and a control unit (2) that controls a first output source (12), a second output source (13), and a third output source (14) according to the inclination angle and twist angle of the tip (27) with respect to the base end (11).

Description

[Technical Field]

[0001] The present invention relates to a robot having multiple arm sections, and more particularly to a robot capable of suitably reproducing the movement of the wrist section. [Background technology]

[0002] Regarding robot arms for industrial robots, the technologies described in Patent Documents 1 to 4 are conventionally known as robots that simulate the movements of a human hand.

[0003] Patent Document 1 (International Publication No. 2013 / 014720: WO2013 / 014720) describes a parallel link robot (10) in which a base (100) and an end effector (500) are connected by three link sections (300). In Patent Document 1, the end effector (500) and each link section (300) are connected by three-degree-of-freedom ball joints (400). Furthermore, in Patent Document 1, each link section (300) and the base (100) are connected by two-degree-of-freedom interference drive mechanisms (200). The positioning of the end effector (500) is performed by controlling the actuator of the interference drive mechanism (200). In the interference drive mechanism (200) of Patent Document 1, the link section (300) is operated using two drive sources, a first actuator (202) and a second actuator (203), which are fixed to the base section (100).

[0004] Patent Document 2 (Japanese Patent Publication No. 2014-46406) describes a parallel link robot (10) in which a base end (11) and a movable part (12) are connected by three sets of link sections (20a-20c). Each link section (20a-20c) has a drive link (21a) and passive links (22a, 23a) composed of parallel links. The drive link (21a) is individually controlled by actuators (13a-13c) to perform positioning. Patent Document 2 describes a configuration in which the drive link (21a) and passive links (22a, 23a) are connected by ball joints (42a, 42b). Furthermore, Patent Document 2 also describes a configuration in which the passive links (22a, 23a) and the movable part (12) are connected by ball joints (42c, 42d).

[0005] Patent Document 3 (Japanese Patent Publication No. 2017-217709) describes a parallel link robot (10) in which a base (12) and a movable part (14) are connected by three sets of link parts (16a-16c). Each link part (16a-16c) has one drive link (20a-20c) and a pair of parallel passive links (22a-22c). The drive links (20a-20c) and the passive links (22a-22c), and the passive links (22a-22c) and the movable part (14) are connected by ball joints (24a-24c, 26a-26c).

[0006] Patent Document 4 (Japanese Unexamined Patent Publication No. 2014-73541) describes an industrial robot in which a base (1) and a head (5) are connected by three sets of arms (6). The arms (6) in Patent Document 4 have a first arm (10) and a pair of parallel rods (13, 13). In Patent Document 4, the first arm (10) and the rods (13, 13) are connected via ball joints. Furthermore, in Patent Document 4, sockets (24) constituting ball joints are arranged at the tips of the rods (13, 13) and connected to brackets (15) of the head (5). [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] International Publication No. 2013 / 014720 ("0012"-"0054", Figures 1 and 2) [Patent Document 2] Japanese Patent Publication No. 2014-46406 ("0012"-"0025", Figures 1-3) [Patent Document 3] Japanese Patent Publication No. 2017-217709 ("0017"-"0022", Figures 1-2) [Patent Document 4] Japanese Patent Publication No. 2014-73541 ("0024"-"0057", Figures 1-4) [Non-patent literature]

[0008] [Non-Patent Document 1] Tomomichi Sugihara, Jotaro Nomi, Analysis of a movable zero-degree-of-freedom mechanism, Proceedings of the 23rd Robotics Symposium, pp. 85-90, (2018) [Non-Patent Document 2] YJ Kim, JI Kim, and W. Jang. Quaternion Joint: Dexterous 3-DOF Joint Representing Quaternion Motion for High-Speed ​​Safe Interaction. Proc. 2018 IEEE / RSJ International Conference on Intelligent Robots and Systems (IROS), pp. 935-942, (2018). [Overview of the project] [Problems that the invention aims to solve]

[0009] (Problems with conventional technology) In industrial robots, in order to simulate and reproduce the movements of a human hand to perform fine operations, in addition to the movement in the direction of extending the hand, movements such as tilting or twisting the hand at the wrist part are required. That is, an operation of approaching or separating the base part and the end effector (a telescopic operation), an operation of tilting the end effector with respect to the base part in the telescopic direction (Z direction) (tilting operation), and an operation of rotating the end effector with respect to the base part around the telescopic direction (Z direction) (twisting operation) need to be realized.

[0010] In the technology described in Patent Document 1, interference driving is used for the joint driving part, two motors are required for one joint, and in its embodiment, it has six degrees of freedom. There are problems that it is not compact and is redundant when used for the wrist. In the technologies described in Patent Documents 2 to 4, although the movement of extending the hand (translational movement) is possible, the movements of tilting or twisting the wrist are impossible. If an attempt is made to realize a twisting movement, the entire base needs to be rotated, or it is necessary to add one axis like the shaft driving motor 4 or the rotating shaft 8 described in Patent Document 4. Even in that case, the movement of tilting the wrist cannot be performed.

[0011] Although it is possible to realize by individually providing dedicated configurations for the telescopic operation, tilting operation, and twisting operation, if dedicated configurations are individually provided, there is a problem that the entire robot becomes larger. Also, if dedicated configurations are individually provided, a drive source (motor) needs to be installed for each, resulting in problems such as increased weight and soaring costs.

[0012] The technical problem of the present invention is to be able to realize a posture in which the tip part is tilted and a twisted posture with respect to the base end part, and to reduce the weight and cost of the robot joints as a whole.

Means for Solving the Problem

[0013] In order to solve the above technical problem, the robot according to the invention described in claim 1 a base end part, a tip part arranged to face the base end part, A first output source supported at the base end portion and performing an output centered on a first output shaft; A second output source supported at the base end portion and performing an output centered on a second output shaft intersecting the first output shaft; A third output source supported at the base end portion and performing an output centered on a third output shaft intersecting the first output shaft and the second output shaft; A first arm having one end connected to the output side of the first output source and the other end connected to the tip end portion; A second arm having one end connected to the output side of the second output source and the other end connected to the tip end portion; A third arm having one end connected to the output side of the third output source and the other end connected to the tip end portion; A first rolling support member disposed between the other end of the first arm and the tip end portion and supporting the tip end portion so as to be roll-rotatable with three degrees of freedom with respect to the first arm; A second rolling support member disposed between the other end of the second arm and the tip end portion and supporting the tip end portion so as to be roll-rotatable with three degrees of freedom with respect to the second arm; A third rolling support member disposed between the other end of the third arm and the tip end portion and supporting the tip end portion so as to be roll-rotatable with three degrees of freedom with respect to the third arm; A control unit that calculates a first rotation angle around the first output shaft, a second rotation angle around the second output shaft, and a third rotation angle around the third output shaft according to the tilt angle and twist angle of the tip end portion with respect to the base end portion, and controls the first output source, the second output source, and the third output source; characterized by comprising the above.

[0014] The invention according to claim 2 is the robot according to claim 1, The first output shaft, the second output shaft, and the third output shaft radially arranged at 120° intervals around a predetermined center position at the base end portion; characterized by comprising the above.

[0015] The invention described in claim 3 is, in the robot described in claim 1, A first free joint is positioned between the first output source and the first arm, and provides rotational support for the first arm relative to the first output source, A second free joint is positioned between the second output source and the second arm, and provides rotational support for the second arm relative to the second output source, A third free joint is positioned between the third output source and the third arm, and provides rotational support for the third arm relative to the third output source, It is characterized by having the following features.

[0016] The invention described in claim 4 is, in the robot described in claim 1, The first arm, the second arm, and the third arm are each composed of a single crank-shaped member, It is characterized by having the following features. [Effects of the Invention]

[0017] According to the invention described in claim 1, it is possible to achieve a posture in which the tip is inclined relative to the base and a twisted posture, and the robot joint as a whole can be made lighter and less expensive. According to the invention described in claim 2, tilted and twisted positions can be achieved with a uniform load using output shafts arranged radially at 120° intervals. According to the invention described in claim 3, compared to the case without a free joint, the power source can be fixed to the base end, the load on the power source can be reduced, and the rigidity of each arm can be increased. According to the invention described in claim 4, compared to the case where the crank shape is not used, interference of the arms can be suppressed when the arms are in a twisted position, and the twist angle can be increased. [Brief explanation of the drawing]

[0018] [Figure 1] Figure 1 is a schematic diagram illustrating the robot according to Embodiment 1 of the present invention. [Figure 2]Figure 2 is an enlarged view of the base portion of the robot in Example 1. [Figure 3] Figure 3 is a diagram of the mechanism of the robot in Example 1. [Figure 4] Figure 4 shows the kinematic model of the robot in Example 1. [Figure 5] Figure 5 shows the simulation results of the numerical solution for the robot in Example 1. [Figure 6] Figure 6 is an explanatory diagram of the operation of the robot arm in Embodiment 1, with Figure 6A showing the arm before operation and Figure 6B showing the arm during twisting operation. [Modes for carrying out the invention]

[0019] Next, specific examples of embodiments of the present invention (hereinafter referred to as "examples") will be described with reference to the drawings, but the present invention is not limited to the following examples. In the following explanation using diagrams, diagrams of components other than those necessary for the explanation have been omitted as appropriate for ease of understanding. [Examples]

[0020] Figure 1 is a schematic diagram illustrating the robot according to Embodiment 1 of the present invention. In Figure 1, the robot system S of Embodiment 1, which is an example of a robot of the present invention, comprises a robot arm 1 and a computer device 2, which is an example of an information processing device and an example of a control unit. The computer device 2 of Embodiment 1 is composed of a so-called microcomputer. That is, the computer device 2 is composed of an I / O (input / output interface) that performs input / output of signals to and from the outside and adjustment of input / output signal levels, a ROM (read-only memory) that stores programs and data for necessary startup processing, a RAM (random access memory) for temporarily storing necessary data and programs, a CPU (central processing unit) that performs processing according to the startup program stored in the ROM, etc., and a clock oscillator, etc. Various functions can be realized by executing the programs stored in the ROM and RAM, etc.

[0021] Computer device 2 is connected to robot arm 1 via a cable (not shown). A joystick 4, which is an example of an operating device, is connected to the computer device 2. The joystick 4 allows the user to operate the handle portion 4a. The handle portion 4a can be tilted forward, backward, left, and right around its lower end, and can also be rotated (twisted) with the longitudinal direction of the handle portion 4a as the axis. The computer device 2 acquires the input operation of the joystick 4 and sends a control signal to the robot arm 1 in response to the operation of the joystick 4. Therefore, the robot arm 1 can be operated by operating the joystick 4.

[0022] Each drive source of the robot arm 1 in Embodiment 1 is supplied with power from the computer device 2, and control signals are transmitted to it. Note that this is not limited to transmission via cables; control signals can also be transmitted via wireless communication or other means. Furthermore, the computer device 2 is not limited to a microcomputer, and can be arbitrarily changed to a configuration that includes a display and a computer body, a server connected to a network, or a cloud-type configuration.

[0023] Figure 2 is an enlarged view of the base portion of the robot in Example 1. Figure 3 is a diagram of the mechanism of the robot in Example 1. In Figures 1 to 3, the robot arm 1 has a base portion 11 as an example of a base end. In Embodiment 1, the base portion 11 is configured in the shape of a disc, but it is not limited to a disc shape and can be any shape such as a rectangular plate. A first motor 12 as an example of a first output source, a second motor 13 as an example of a second output source, and a third motor 14 as an example of a third output source are supported on the upper surface of the base portion 11. The first motor 12, the second motor 13, and the third motor 14 are arranged at 120° intervals with respect to the center position 11a of the disc-shaped base portion 11. In Embodiment 1, the output shafts 12a to 14a of each motor 12 to 14 extend along the radial direction centered on the center position 11a.

[0024] A first bracket 21 is rotatably supported on the output shaft 12a of the first motor 12. The first bracket 21 has a plate portion 21a and a pair of rotatable support portions 21b. The rotatable support portions 21b are formed in a shape that is bent from both ends of the plate portion 21a. The rotatable support portions 21b are supported by the first motor 12 in a state that allows them to rotate about the output shaft 12a. A first free joint 22 is supported on the plate portion 21a. One end of a first arm 23 is supported on the first free joint 22. The first free joint 22 supports the first arm 23 with respect to the first bracket 21 in a rotatable (freely rotatable) state. The axial direction of the rotation axis 22a of the first free joint 22 is non-parallel to, i.e., intersects with, the axial direction of the output shaft 12a. In Embodiment 1, the rotation axis 22a of the first free joint 22 and the output shaft 12a are arranged at a 90° intersection.

[0025] The first arm 23 has a first arm base end portion 23a, a first base end bent portion 23b, a first main arm 23c, a first tip bent portion 23d, and a first arm tip portion 23e. The base portion 23a of the first arm extends outward in a radial direction with respect to the rotation axis 22a. The first base bent portion 23b is formed in a shape that is bent radially outward from the tip of the first arm base end portion 23a relative to the center position 11a. The first main arm 23c extends radially from the rotation axis 22a, and one end is formed to be bent 90° from the first base bent portion 23b. The first bent tip portion 23d is formed in a shape that is bent inward in a radial direction relative to the center position 11a from the tip of the first main arm 23c. The first arm tip portion 23e extends outward radially from the tip portion of the first tip bending portion 23d, with respect to the rotation axis 22a. Therefore, the first arm 23 of Example 1 is formed in a so-called crank shape overall.

[0026] A first universal joint 24, as an example of a connecting means, is connected to the tip 23e of the first arm. The first universal joint 24 is rotatable around a universal first axis 24a and a universal second axis 24b that intersects the universal first axis 24a. In other words, the first universal joint 24 has a two-degree-of-freedom configuration. An end effector 27, as an example of a tip, is supported at the tip of the first universal joint 24 via a first ball joint 26, as an example of a first rolling support. The first ball joint 26 is a conventionally known type in which a ball is supported in a state of free rotation in a receiving part with a spherical inner surface. Therefore, the first ball joint 26 has a three-degree-of-freedom configuration.

[0027] The second motor 13 is provided with a second bracket 31, a second free joint 32, a second arm 33, a second universal joint 34, and a second ball joint 36, configured in the same way as for the first motor 12. Similarly, the third motor 14 is provided with a third bracket 41, a third free joint 42, a third arm 43, a third universal joint 44, and a third ball joint 46. Therefore, a detailed explanation of each component 31-36 and 41-46 will be omitted.

[0028] (Kinematics of the robot in Example 1 using numerical methods) Figure 4 shows the kinematic model of the robot in Example 1. The mechanical structure of the robot arm 1 in Example 1 can be treated as a type of open link mechanism with branching points. Considering the robot arm 1 in Example 1 to consist of one trunk (for example, the first arm 23 and its system) and two branches (the system of the second arm 33 and the system of the third arm 43), the kinematic model of the robot constructed is shown in Figure 4. The inverse kinematics can be solved for a parallel mechanism by solving the inverse kinematics so that the branching point and the ends of the two branches are in a predetermined position and orientation. The area within frame 101 corresponds to the 3-degree-of-freedom contrapositive of ball joints (rod ends) 26, 36, and 46. The joint displacement vector q of the entire link system is defined as shown in equations 1 and 2 below.

number

number

[0029] Note that in equations 1 and 2, i=0, 1, and 2 represent the main stem (0) and the branched branches (1, 2). When this link system is in the reference orientation q=0, the link vector is L as shown in Figure 4. ij , joint axis vector S ij The values ​​j=0, ..., 5 indicate the order of links and joints. The rotation matrix of the link (ij) is R ij This is defined as follows. Also, the link vector l after joint rotation. ij , joint axis vectors ij The following numbers are 3 and 4.

number

number

[0030] Position vector p of each joint relative to the absolute coordinate system ij The results are as follows: numbers 5 and 6.

number

number

Equation

[0031] At this time, using the velocity ratio matrix (basic Jacobian matrix) J(q) and the joint velocity q · , the velocity vector v(q) is expressed by Equations (8) and (9) below.

Equation

Equation

[0032] The link vector L 00 is set on the pedestal portion 11. Also, the positions of each limb (corresponding to the positions of the second motor 13 and the third motor 14) d p 15 , d p 25 and the orientation d R 15 , d R 25 are also set on the pedestal portion 11. The position of the end effector 27 is not specified, and the orientation R 05 is set as the target orientation. The numerical solution of the inverse kinematics (q 00 , q 14 and q 24 ) corresponding to the motor angles is obtained by iterative calculation.

[0033] FIG. 5 is a diagram of the simulation result of the numerical solution of the robot of Example 1. An example of the simulation result of the inverse kinematics is shown in FIG. 5. In FIG. 5, the black, red, and green lines indicate the trunk and the limbs, respectively. Therefore, by performing the above numerical calculations in the computer device 2 of Example 1, it is possible to calculate the control amount (motor rotation angle) for each motor 12-14 in relation to the target posture input by the joystick 4. Thus, by controlling each motor 12-14 according to the calculated control amount, it is possible to control the robot arm 1 to the target posture.

[0034] (Effect of Example 1) In the robot arm 1 of Embodiment 1, which has the above configuration, the end effector 27 is supported by three arms 23, 33, and 43 relative to the base 11. When the joystick 4 is operated, control signals are sent from the computer device 2 to each motor 12-14 according to the operation of the joystick 4, i.e., tilting forward and backward, tilting left and right, twisting around the vertical axis, or a combination thereof. Then, each motor 12-14 rotates according to the control signal, and each arm 23, 33, and 43 moves. As a result, the end effector 27 tilts or twists relative to the base 11 in response to the operation of the joystick 4.

[0035] In the prior art described in Non-Patent Documents 1 and 2, the end effector 27 had a configuration in which only a 2-degree-of-freedom universal joint was provided, and the 3-degree-of-freedom ball joints 26, 36, and 46 were not provided. In this case, when tilting, the movement is rotational within the curved surface (2-dimensional, around the XY axes) including the end effector 27. However, even when trying to twist it so as to rotate around the vertical direction (Z-axis direction), the 2-degree-of-freedom universal joints did not have enough degrees of freedom to achieve the desired posture. Therefore, it was necessary to add another axis on the end effector 27 for twisting operations (see Non-Patent Document 2).

[0036] Figure 6 is an explanatory diagram of the operation of the robot arm in Embodiment 1, with Figure 6A showing the arm before operation and Figure 6B showing the arm during twisting operation. In contrast, in the robot arm 1 of Example 1, the end effector 27 is connected by three-degree-of-freedom ball joints 26, 36, and 46. Therefore, there are sufficient degrees of freedom, and as shown in Figures 6A and 6B, a twisted posture can be achieved in which the end effector 27 is rotated relative to the base portion 11 before and after the twisting operation. Thus, a twisted posture that cannot be achieved with the technologies described in Patent Documents 2 to 4 can be achieved, and a robot arm 1 that is closer to the behavior of a wrist can be realized. In particular, in Embodiment 1, the configuration of three motors 12-14 and three arms 23, 33, and 43 makes it possible to achieve tilted and twisted postures of the end effector (tip) 27 relative to the base (base) 11. Therefore, wrist movements can be achieved with a simpler configuration compared to cases where a dedicated configuration for tilting and twisting is required. Thus, wrist movements can be achieved with a lightweight and low-cost robot arm 1 overall.

[0037] In the configuration described in Patent Document 1, interference drive is used in the joint drive unit, and two motors are used for one joint. In that embodiment, there are six degrees of freedom, combining three degrees of freedom for translational motion and three degrees of freedom for rotational motion, so tilting and torsional motion can also be realized. However, it is not compact enough for use on the wrist, and the three degrees of freedom for translational motion are redundant. In contrast, in Embodiment 1, the number of motors is reduced to three, and the main degrees of freedom are tilting and torsion, thus solving the problems of Patent Document 1. In other words, in Patent Document 1, it was not possible to achieve twisting and tilting of the end effector without controlling the two axes on the base connection side. In contrast, in the robot arm 1 of Embodiment 1, it is possible to calculate the posture of the end effector 27 by the movement of one axis of the output shafts 12a to 14a of the motors 12 to 14 arranged on the base portion 11 side of arms 23, 33, and 43. That is, by providing a drive source and controlling only one axis of arms 23, 33, and 43, it is possible to achieve twisting and tilting of the end effector 27.

[0038] Furthermore, in the robot arm 1 of Example 1, arms 23, 33, and 43 have a crank shape. In the case of a straight arm, when changing to a twisted posture, the arm moves inward (towards the center position 11a), making it easy for the arms to interfere with each other. In contrast, in the crank-shaped arms 23, 33, and 43 of Example 1, the main arms 23c, 33c, and 43c are positioned outward from the center position 11a compared to a straight arm, so even if they move inward when changing to a twisted posture, interference is less likely.

[0039] (Example of change) Although embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the gist of the present invention as described in the claims. Examples of modifications to the present invention (H01) to (H05) are shown below. (H01) In the above embodiment, a configuration in which free joints 22, 32, and 42 are provided between each motor 12 to 14 and the arms 23, 33, and 43 was illustrated, but the system is not limited thereto. It is also possible to install the free joints 22, 32, and 42 between the motors 12 to 14 and the base portion 11. Therefore, the motors 12 to 14 can be directly supported by the base portion 11, or they can be indirectly supported via the free joints 22, 32, and 42. Furthermore, in the above embodiment 1, a configuration in which the rotation axes of each motor 12 to 14 are arranged radially with respect to the base portion 11 was illustrated, but the system is not limited thereto. It is also possible to install the rotation axes of the motors 12 to 14 circumferentially, such as the free joints 22, 32, and 42, and to arrange the rotation axes of the free joints 22, 32, and 42 radially, such as the rotation axes of the motors 12 to 14.

[0040] (H02) In the above embodiment, a method of manually inputting the target's posture using the joystick 4 was illustrated, but the invention is not limited to this. Any method can be used to input the target's posture, such as inputting the target's posture based on pre-programmed data, or transmitting the target's posture from a personal computer or server device. (H03) In the above embodiment, the arms 23, 33, and 43 were shown as being in a crank shape, but are not limited to this. Any shape can be adopted, such as a straight shape or an arc-shaped curved shape.

[0041] (H04) In the above embodiment, the shafts of the free joints 22, 32, and 42 between each motor 12 to 14 and the arms 23, 33, and 43 are shown to intersect with the shafts of each motor 12 to 14, respectively, but the embodiment is not limited to this. An offset, misaligned shaft relationship is also acceptable. (H05) The above embodiment describes an example of use in the wrist of a robot arm, but is not limited thereto. Since tilting and twisting motions are possible while the end effector is supported by three motors, it can be used, for example, in the waist or neck of a humanoid robot that needs to support weight. [Explanation of Symbols]

[0042] 2... Control unit, 11...Proximal end, 12...First output source, 12a...First output shaft, 13...Second output source, 13a...Second output shaft, 14…Third output source, 14a...Third output shaft, 22... The first free joint, 23... First arm, 26...First rolling support member, 27...Tip part, 32...Second free joint, 33... Second arm, 36...Second rolling support member, 42... The third free joint, 43... The third arm, 46...Third rolling support member, S...Robot.

Claims

1. The base and, A tip portion positioned opposite the base end, A first output source supported at the base end and providing output centered on the first output shaft, A second output source that is supported at the base end and outputs around a second output axis that intersects the first output axis, A third output source supported at the base end and which outputs around a third output axis that intersects the first output axis and the second output axis, A first arm, one end of which is connected to the output side of the first output source and the other end of which is connected to the tip, A second arm, one end of which is connected to the output side of the second output source and the other end of which is connected to the tip, A third arm, one end of which is connected to the output side of the third output source and the other end of which is connected to the tip, A first rolling support member is positioned between the other end of the first arm and the tip portion, and supports the tip portion so that it can roll and rotate with respect to the first arm in three degrees of freedom. A second rolling support member is positioned between the other end of the second arm and the tip portion, and supports the tip portion so that it can roll and rotate with respect to the second arm in three degrees of freedom. A third rolling support member is positioned between the other end of the third arm and the tip portion, and supports the tip portion so that it can roll and rotate with respect to the third arm in three degrees of freedom. A control unit that calculates a first rotation angle around the first output axis, a second rotation angle around the second output axis, and a third rotation angle around the third output axis according to the inclination angle and twist angle of the tip portion relative to the base portion, and controls the first output source, second output source, and third output source. A robot characterized by having the following features.

2. At the base end, the first output shaft, the second output shaft, and the third output shaft are arranged radially at 120° intervals with respect to a predetermined central position. The robot according to claim 1, characterized by being equipped with

3. A first free joint is positioned between the first output source and the first arm, and provides rotational support for the first arm relative to the first output source, A second free joint is positioned between the second output source and the second arm, and provides rotational support for the second arm relative to the second output source, A third free joint is positioned between the third output source and the third arm, and provides rotational support for the third arm relative to the third output source, The robot according to claim 1, characterized by being equipped with

4. The first arm, the second arm, and the third arm are each composed of a single crank-shaped member. The robot according to claim 1, characterized by being equipped with

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