JPH1177560A - Articulated robot and position teaching method of articulated robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow to teach the positions of operating parts easily by maintaining the relative position relation of plural operating parts, in the joint parts to combine plural operating parts. SOLUTION: In an articulated robot 1 fin which plural operating parts are provided, and the position of a moved random operating part is taught by moving the random operating part directly by an operator, a brake mechanism 30 to maintain the relative positional relation of plural operating parts which are combined through the joint parts 10, 11, 12, and 13 is furnished at the joint parts 10, 11, 12, and 13 to combine the plural operating parts, and this brake mechanism 30 can release the maintaining of the relative positional relation of plural operating parts, at the joint parts 10, 11, 12, and 13 relating to a random operating part the operator is going to operate by moving directly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an articulated robot and a position teaching method for the articulated robot.

[0002]

2. Description of the Related Art Position teaching (teaching) in a conventional robot is performed by directly inputting numerical data, or in a state where the robot is not operating, the robot is manually moved to a position where the robot is to be actually taught, and the robot itself is taught. A method of performing teaching by storing the position information of the position sensor has been performed. In the input of numerical data, it is difficult to directly obtain numerical data of position information accurately due to the processing accuracy and assembly accuracy of robot parts. In practice, an input device (teaching pendant,
In many cases, a method of performing teaching by moving a robot using a teaching box or the like, and a method of direct teaching in which an operating position is taught by directly grasping the tip of the robot, a wrist, or the like, are adopted.

[0003]

In the case of teaching using an input device, there is a disadvantage that it takes time to perform teaching while actually moving each joint axis of the robot. Also, direct teaching requires less time than using an input device, but when the number of operating parts such as robot arms increases and the number of shafts and joints increases, one worker can hold many tips. It is difficult to perform position teaching. This is especially true when the robot's posture changes due to joint displacement, such as an autonomous mobile robot, or when it falls down, or when the joints or arms move due to the effects of external forces such as gravity. Become noticeable.

In the articulated robot 1 as shown in FIG. 1, the joints move due to external force such as gravity when the motor power is turned off or the servo is turned off, and a desired posture is maintained when performing direct teaching. Difficult to teach position. Therefore, the present invention solves the above-mentioned problem, and in a joint portion connecting a plurality of operating units, by maintaining the relative positional relationship of the plurality of operating units, it is possible to easily teach the position of the operating unit. It is an object of the present invention to provide a position teaching method for a mobile robot and an articulated robot.

[0005]

SUMMARY OF THE INVENTION According to the present invention, there is provided the present invention comprising a plurality of operating units, wherein an operator directly moves an arbitrary operating unit to teach the position of the moved arbitrary operating unit. In an articulated robot that is supposed to
The joint section connecting the plurality of operating sections is provided with a brake mechanism for maintaining a relative positional relationship between the plurality of operating sections connected via the joint section. This is achieved by an articulated robot characterized in that it is possible to release the holding of the relative positional relationship between a plurality of operating units at a joint associated with an arbitrary operating unit to be operated.

In the present invention, when the operator directly moves any of the plurality of operating units to teach the position of the moved arbitrary operating unit, the brake mechanism controls the plurality of operating units. The relative positional relationship between the plurality of operating units in the joint part to be connected is maintained. This brake mechanism can release the holding of the relative positional relationship between the plurality of operating units at a joint portion related to an arbitrary operating unit that the operator intends to directly move to operate. As a result, it is possible to easily change the relative positional relationship of only an arbitrary moving part that the operator intends to move and operate, and the brake mechanism works at the joint part connecting the other plural moving parts. The relative positional relationship between the plurality of motion parts in the joint part is maintained. Therefore, the operator can easily change the relative positional relationship of an arbitrary operation unit and teach the position of the arbitrary operation unit without changing the posture of the articulated robot.

The object of the present invention is to provide a multi-joint in which the operator directly moves an arbitrary one of a plurality of operating units to teach the position of the moved operating unit. In the type robot, the relative positions of the plurality of operating units connected via the joints are held by a brake mechanism arranged at a joint connecting the plurality of operating units, and an operator can operate an arbitrary operating unit. In order to change the relative position of the motion part at a certain joint part by moving directly,
An operator operates a brake mechanism at a certain joint to release the state of holding the relative positions of the plurality of operating units by the brake mechanism, and teaches the position of an arbitrary operating unit at a certain joint. This is achieved by the position teaching method of the articulated robot.

In the present invention, when the operator directly moves any of the plurality of operating units to teach the position of the moved arbitrary operating unit, the brake mechanism controls the plurality of operating units. The relative positional relationship between the plurality of operating units in the joint part to be connected is maintained. This brake mechanism can release the holding of the relative positional relationship between the plurality of operating units at a joint portion related to an arbitrary operating unit that the operator intends to directly move to operate. As a result, it is possible to easily change the relative positional relationship of only an arbitrary moving part that the operator intends to move and operate, and the brake mechanism works at the joint part connecting the other plural moving parts. The relative positional relationship between the plurality of motion parts in the joint part is maintained. Therefore, the operator can easily change the relative positional relationship of an arbitrary operation unit and teach the position of the arbitrary operation unit without changing the posture of the articulated robot.

[0009]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Note that the embodiments described below are preferred specific examples of the present invention,
Although various technically preferable limits are given, the scope of the present invention is not limited to these modes unless otherwise specified in the following description.

FIG. 1 shows a preferred embodiment of the articulated robot according to the present invention. The articulated robot is in the form of an animal having four legs, and the articulated robot 1 has a main body 2, a right front foot 3, a left front foot 4, a right rear foot 5,
It has a left hind foot 6, a head 7, a body part 8, a tail 9, and the like.
The articulated robot 1 is provided with a brake mechanism at joints 10, 11, 12, and 13 such as a right forefoot 3, a left forefoot 4, a right hindfoot 5, and a left hindfoot 6. By utilizing the operation of this brake mechanism, the relative positional relationship between the operating parts (legs) of each of the right forefoot 3, the left forefoot 4, the right hindfoot 5, and the left hindfoot 6 is directly taught by the operator using the direct teaching method. Can be taught. The main body 2 includes brackets 20, 21, 2 for the right forefoot 3, the left forefoot 4, the right hindfoot 5, and the left hindfoot 6.
2 and 23 are provided. The head 7 is set at the upper end of the main body 2, and the body 8 is located behind the head 7. The tail 9 protrudes from the body 8.

Each element set for the main body 2 will be described sequentially. First, the right forefoot 3 is a leg 3a, a leg 3b,
Joint part 10, brake mechanism 30, motors 3c, 3d,
3e. The upper end of the leg 3a is a bracket 20
The leg 3a is rotatable in the R1 direction about the center axis CL1. The legs 3a and 3b are
They are connected by a joint part 10. The motor 3c is built in the main body 2, and when the motor 3c operates, the bracket 20 can rotate in the direction of R2 about the central axis CL2. When the motor 3d operates, the leg 3a can rotate in the R1 direction about the center axis CL1. When the motor 3e operates, the leg 3b can rotate in the R3 direction about the center axis CL3 with respect to the leg 3a.

The left forefoot 4 is composed of legs 4a and 4b,
1, a brake mechanism 31, and motors 4c, 4d, and 4e. The leg 4a is connected to the bracket 21 so that it can rotate in the R4 direction about the center axis CL4. The leg 4b is connected to the leg 4a by a connecting portion 11. The motor 4c is built in the main body 2, and when the motor 4c operates, the bracket 21 rotates in the R5 direction about the center axis CL5. When the motor 4d operates, the leg 4a is moved with respect to the center axis C with respect to the bracket 21.
It rotates in the R4 direction about L4. When the motor 4e operates, the leg 4b rotates in the R6 direction about the center axis CL6.

Next, the right hind leg 5 includes the legs 5a and 5b, the joint portion 12, the brake mechanism 30, and the motors 5c, 5d and 5e.
have. The upper end of the leg 5a is connected to the bracket 22. When the motor 5c operates, the bracket 22 can rotate in the R7 direction about CL7.
When the motor 5d operates, the leg 5a can rotate in the R8 direction around the CL8. When the motor 5e operates, the leg 5b can rotate in the R9 direction about the center axis CL9.

The left hind foot 6 includes legs 6a and 6b,
3. It has a brake mechanism 30, and motors 6c, 6d, 6e. When the motor 6c operates, the bracket 23
It can rotate in the R10 direction about L10. Motor 6
When d is activated, the leg 6a is moved to R11 around CL11.
Can rotate in any direction. When the motor 6e operates, the leg 6b can rotate in the R12 direction about the center axis CL12. As described above, each of the right forefoot 3, the left forefoot 4, the right hindfoot 5, and the left hindfoot 6 can be driven by the motors around the plurality of axes.

The head 7 has motors 7a, 7b, 7c. When the motor 7a operates, the head 7 can swing about the CL20 in the direction of R20. When the motor 7b operates,
The head 7 swings in the R21 direction around the CL21.
When the motor 7c operates, the head 7 can swing in the R22 direction about the central axis CL22. The body 8 has a motor 8a. When the motor 8a operates, the tail 9 swings in the R23 direction about the center axis CL23.

FIG. 2 shows the control unit 100 of the articulated robot 1 shown in FIG. 1 and the motors and motors of the right forefoot 3, left forefoot 4, right hindfoot 5, left hindfoot 6, head 7, and tail 8. 4 shows an example of a connection relationship between position sensors. The control unit 100 includes the memory 1
01 and a CPU (Central Processing Unit) 102, and the bus 103 of the CPU 102
They are connected to the left forefoot 4, right hindfoot 5, left hindfoot 6, head 7, and tail 8 elements. The right forefoot 3 is a motor 3c, 3d,
3e and position sensors 3P1, 3P2, 3P3. The motors 3c, 3d, 3e are connected to a driver 3D, respectively, and the position sensors 3P1, 3P2, 3
P3 is also connected to the driver 3D. Each driver 3D is connected to the bus 103.

Similarly, the motors 4c, 4d,
4e, the position sensors 4P1, 4P2, and 4P3 are connected to the driver 4D. The motors 5c, 5d of the right hind foot 5,
5e and the position sensors 5P1, 5P2, 5P3 are connected to the driver 5D, respectively. Motor 6 for left rear foot 6
c, 6d, 6e and position sensors 6P1, 6P2, 6P3
Are connected to the driver 6D. Motor 7 on head 7
a, 7b, 7c and position sensors 7P1, 7P2, 7P3
Are connected to the driver 7D. Motor 8 of tail 8
a and the position sensor 8P1 are connected to the driver 8D.

Right front foot 3, left front foot 4, right rear foot 5, left rear foot 6
Position sensors 3P1, 3P2, 3P3, 4P1, 4P
2,4P3,5P1,5P2,5P3,6P1,6P
2, 6P3 is for obtaining position information at each location. For example, a rotation angle sensor can be used as these position sensors. Position information obtained by the position sensors 3P to 6P3 such as the rotation angle sensor is
When fed back to the CPU, the CPU 102 gives a command to each driver based on the fed back position information. Accordingly, the corresponding driver performs servo control on the corresponding motor, and the motor 3d rotates to the command position given by the CPU 102.

Next, the joint parts 10, 11, 12, 13 of the right forefoot 3, the left forefoot 4, the right hindfoot 5, and the left hindfoot 6 of FIG. 1 and the brake mechanism 30 will be described. The joint portion 13 of the left hind leg 6 and the brake mechanism 30 will be described as representatives, and the joint portion of the four legs 3, 4, 5, and 6 and the brake mechanism will be described.

FIGS. 3 and 4 show the joint 13 and the brake mechanism 30 of the left rear foot 6 in FIG. Joint part 13
Is a portion connecting the legs 6a and 6b of the left hind leg 6. The leg 4 and the leg 6 are rotatably connected by a joint 13. The joint part 13 has three bearings 113
a, 113b, 113c and an output shaft 109, and the output shaft 109 has bearings 113a, 113b,
It is rotatably supported by 113c. Output shaft 10
9 passes through the leg 6a and the leg 6b, and one end side of the output shaft 109 is fixed to the bracket 6 of the leg 6a by a screw 108b. The bracket 105 is fixed to the leg 6a.

The output shaft 109 has a gear 110.
This gear 110 has 110a, 110b, 110c, 1
The leg 6b is connected to the gear 110g of the motor 6e via 10d, 110e, and 110f. Also gear 110
b is the gear 1 of the position sensor 6P3 such as a rotation angle sensor.
It is engaged for 10h. When the motor 6e is operated, power is transmitted to the output shaft 109 via the gears described above.
The output shaft 109 rotates. At this time, the position sensor 6P3 also rotates to provide position information. At this time, the position sensor 6
The position information obtained by P3 is fed back to the CPU 102 as described in FIG.

The brake mechanism 30 is set at the tip 130 of the output shaft 109. This brake mechanism 30
Has a knob 133 as a rotating body, a spring 134, a stop plate 137, and a screw 138. This screw 138
Fix the stopper plate 137 to the protruding portion 130. The stop plate 137 presses the spring 134 with the knob 133 in the T direction in FIG.

FIGS. 5 and 6 show a released state of the brake mechanism 30 of FIG. 3 and an applied state of the holding torque by the brake mechanism 30. FIG. A guide groove 145 is formed on the outer periphery of the knob 133 of the brake mechanism 30. The protrusion 146 of the protrusion 130 is guided in the guide groove 145.

When the holding torque of the brake mechanism 30 shown in FIG. 5 is released, the protrusion 146 is located at an intermediate position of the guide groove 145 of the knob 133. When the operator rotates the knob 133 by a predetermined angle in the W direction, the protrusion 146 is relatively positioned at the end of the guide groove 145 of the knob 133 as shown in FIG. At this time, the knob 133 is T
Then, the inner end surface 133a of the knob 133 is pressed against the outer surface 105a of the bracket 105 and fixed by frictional force. From this, the legs 6a and 6b
Due to the frictional force between the inner end surface 133a of the knob 133 and the outer surface 105a of the bracket 105, the knob 133 does not rotate. Conversely, when releasing the holding torque by the brake mechanism 30, the operator may turn the knob 133 in the direction opposite to the W direction in FIG.

Next, a position teaching method of the articulated robot will be described with reference to FIGS. 7 and 8 and FIGS. 1 and 2. Referring to FIGS. 7 and 8, the state of the right front foot 3, the left front foot 4, and the right rear foot 5 with respect to the main body 2 is maintained as it is, and the state of only the left rear foot 6 is changed by the direct teaching method. An example in which the operator teaches the position of the rear foot 6 is shown. Therefore, the brake mechanism 3 in the joint portions 10, 11, 12 of the right forefoot 3, the left forefoot 4, and the right hindfoot 5
In a state 0, a holding torque is generated by performing a holding function as shown in FIG. 6, and a state is maintained in which the relative positional relationship of a plurality of legs in each joint portion is held.

On the other hand, the brake mechanism 3 of the left rear foot 6
0 indicates that the holding torque is released as shown in FIG. 5, and the operator changes the position of the leg 6b with respect to the leg 6a by rotating the leg 6b in the V direction in FIG. In this case, the position sensor 6P3 in FIG.
10, 110a, 110b, and 110h, so that the position information corresponding to the angle θ at which the leg 6b tries to rotate in the V direction in FIG.
P3 can be sent to the CPU 102 of FIG. In this way, the operator moves only the leg 6b of the left hind leg 6, which is a target for performing direct teaching,
The position teaching for the leg 6b can be provided to the CPU 102. In this case, the other right forefoot 3, left forefoot 4, and right hindfoot 5 are held by the braking mechanism 30 using the holding torque.
Since the relative positional relationship between the legs is maintained, the positions of the right front foot 3, the left front foot 4, and the right rear foot 5 do not change. Therefore, the position teaching of the leg 6b of the left hind leg 6 can be easily performed while maintaining the posture of the articulated robot 1.

FIG. 8 shows a state in which the leg 6b is further rotated in the X direction from the state of FIG. 7 with respect to the main body 2 to perform direct teaching of the leg 6a. When performing position teaching to a robot, release the brakes of the joints to be moved and apply other brakes to fix the joints.
By doing so, the joints do not move due to external force such as gravity other than the joints whose position is to be taught, and it is not necessary to hold several joints by hand. (FIG. 5) After moving the necessary joints to the desired positions, the process of fixing the joints and moving the position of the next joint to the teaching position was repeated, and finally the positions of all the joints were determined. At step (FIG. 6) the information from the position sensor is stored in the memory of FIG.
Teaching can be performed in a short time. Also, the brake holding torque is adjusted so that it does not move by external force but moves by the force of the operator, and all brakes are kept on. In this case, all the joints of the robot are usually fixed, and move only when the operator moves the joint. In this way, the operator can move the robot to a desired posture, read information from the position sensor into the storage device, and perform teaching in a short time.

In the above-described example of direct teaching, the left hind foot 6 is described by way of example, but the procedure of direct teaching is the same for the right fore foot 3, left fore foot 4, and right hind foot 5. .

Next, another embodiment of the brake mechanism will be described with reference to FIGS. 9 and 10. FIG. The brake mechanism 30 described so far is of a type built in the joint parts 10 to 13 of the right forefoot 3, the left forefoot 4, the right hindfoot 5, and the left hindfoot 6. On the other hand, the brake mechanism 230 of FIGS. 9 and 10 is externally attached (retrofitted) to the joint part.
In the form of 9 and 10, the joint part 1 is shown.
The brake mechanism 230 is capable of generating a holding torque in the joint portion 13 when the brake mechanism 230 is fitted into the joint portion 13 in the direction of arrow F.

The brake mechanism 230 includes a knob 133, a spring 134, a stopper plate 137, and a screw 138. The outer peripheral surface of the knob 133 has a guide groove 14 as shown in FIG.
5 is provided. The protrusion 130 has a protrusion 146 as shown in FIG.
Is to be guided to. Operator 133
By turning in the W direction, it is possible to change from the brake release state in FIGS. 9 and 10 to a state in which a holding torque is generated. When generating the holding torque, the inner surface 133a of the knob 133 comes into contact with the outer surface 105a of the bracket 105 to generate a frictional force, thereby fixing the leg 6a and the leg 6b and applying a predetermined holding torque. generate.

The present invention is not limited to the above embodiment. For example, the holding torque of the brake mechanism may be adjusted in multiple stages, and may be completely fixed or may not be moved by external force but may be moved by the force of an operator (operator). If the motor is moved while the holding torque is being generated by the brake mechanism, the drive circuit, gears, and the motor itself may be damaged.
It is also possible to detect the ON state in which the holding torque is being generated by the brake mechanism, and to prevent the motor from operating while the holding mechanism is generating the holding torque. In this case, the motor is not operated by, for example, giving a command to the driver by the CPU 102 shown in FIG.

In the above-described embodiment, the brake mechanism is a so-called mechanical brake mechanism that generates a frictional force by rotating a knob by an operator to generate a holding torque. It is of course possible to adopt a type in which the holding torque by the brake is generated by such an electric switch.

According to the articulated robot and the position teaching method of the articulated robot of the present invention as described above, it is possible to shorten the work time in the teaching work of the robot and contribute to the efficiency of the work. At the time of teaching, the operation can be easily performed without worrying about the fall of the robot, a change in posture, and the like. Since the teaching can be performed without the influence of the external force, the operator does not need to take an unreasonable posture, so that the physical burden on the operator can be reduced. The present invention can be applied not only to robots but also to machine tools, industrial machines, and the like, and their position information can be created in a short time. As the number of joints increases, the effect of shortening the working time and the like increases.

Although the articulated robot according to the embodiment of the present invention has a shape imitating a four-legged animal such as a dog or a cat, the invention is not limited to this. Of course, the present invention can be applied to a robot, an articulated robot having five or more legs, or another type of articulated robot.

It should be noted that the joint parts 10, 11, and
Although the brake mechanism 30 is set in 12 and 13, the brake mechanism 30 can also be set in the following parts in addition to the above. The brake mechanism 30 can be set at the joint between the bracket 20 and the leg 3a, the joint between the bracket 21 and the leg 4a, the joint between the bracket 22 and the leg 5a, and the joint between the bracket 23 and the leg 6a.

[0036]

As described above, according to the present invention,
By maintaining the relative positional relationship between the plurality of operating units in the joint portion connecting the plurality of operating units, it is possible to easily teach the positions of the operating units.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a preferred embodiment of an articulated robot according to the present invention.

FIG. 2 is a diagram showing a control system of the articulated robot shown in FIG. 1;

FIG. 3 is a sectional view showing an example of a joint part and a brake mechanism on the left hind leg of the articulated robot shown in FIG. 1;

FIG. 4 is a side view showing a joint portion and a brake mechanism of FIG. 3;

FIG. 5 is a diagram showing a state where the brake mechanism of FIG. 3 is released.

FIG. 6 is a diagram showing a state in which the brake mechanism functions to generate a holding torque.

FIG. 7 is a perspective view showing a state where the left hind leg of the articulated robot of FIG. 1 is operated by the direct teaching method to teach position information.

FIG. 8 is a diagram showing a state in which further position information is taught from the state of FIG. 7;

FIG. 9 is a diagram showing an example of an external brake mechanism in the articulated robot according to the present invention.

10 is a diagram showing a state in which the external brake mechanism of FIG. 9 is mounted on a joint portion.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Articulated robot, 2 ... Body, 3 ... Right forefoot, 3a, 3b ... Leg, 4 ... Left forefoot, 4a, 4
b: leg, 5: right hind leg, 5a, 5b: leg, 6
... Left hind leg, 6a, 6b ... Leg, 10, 11, 1
2, 13 ... joint part, 30 ... brake mechanism

Claims (7)

[Claims] An articulated robot having a plurality of operation units, wherein an operator directly moves an arbitrary operation unit to teach the position of the moved arbitrary operation unit. The joint section that connects the sections is provided with a brake mechanism that maintains the relative positional relationship between the plurality of operating sections that are connected through the joint section. An articulated robot characterized in that it is possible to release the holding of the relative positional relationship between a plurality of operating units at a joint portion related to an arbitrary operating unit. 2. The articulated robot according to claim 1, wherein the brake mechanism can be externally attached to the joint. 3. The articulated robot according to claim 1, wherein the brake mechanism has a rotating body, and holds the relative positional relationship between the plurality of operating units in the joint portion by rotating the rotating body. 4. The holding force of the brake mechanism is a force capable of moving a joint portion by an operator's force.
2. The articulated robot according to 1. 5. The position teaching method for an articulated robot according to claim 1, wherein the position of an arbitrary operation unit in the joint is obtained by a position sensor. 6. An articulated robot in which an operator directly moves any of the plurality of operating units to teach the position of the moved operating unit. By the brake mechanism arranged at the joint part to be connected, the relative positions of the plurality of operating parts connected via the joint part are held, and the arbitrary moving part is moved directly by the operator, so that a certain joint part is moved. In order to change the relative position of the moving parts, the operator operates the brake mechanism at a certain joint part to release the state of holding the relative positions of the plural moving parts by the brake mechanism, and to release the arbitrary moving part at a certain joint part. A position teaching method for an articulated robot, wherein the position is taught. 7. The position teaching method for an articulated robot according to claim 6, wherein a position of an arbitrary operation section in the joint portion is obtained by a position sensor.