CN1586831A - Six-freedom remote control arm with gravity compensation and length regulation - Google Patents

Abstract

The invention relates to a data arm mechanism that can be used for remote operation of a humanoid robot. The data arm mechanism is a mechanical arm with 6 rotary joints, and each rotary joint is equipped with a potentiometer as an angle sensor. The data arm has a gravity compensation mechanism, which can guide the movement when the operator wears it, and can also pull it to the required state without wearing it, and does not require external force assistance when pausing at any position. The data arm has a length adjustment mechanism and can be worn by people with different arm lengths. The invention can detect the rotation angles of the teleoperator's shoulder joint, elbow joint and wrist joint in six degrees of freedom. It is suitable for teleoperating robot control platforms and can be worn on human arms for motion extraction.

Description

6-DOF teleoperated arm with gravity compensation and adjustable length

Technical field:

The invention belongs to the field of robots and is mainly used for teleoperation control of the arms of the robot. It is suitable for teleoperating robot control platforms, and can be worn on human arms for motion extraction to obtain the operator's motion information.

Background technique:

Teleoperation is an important technology for robot applications. Through the teleoperation platform, operators can monitor and control remote robots to complete various tasks, so that robots can replace humans in some unreachable, even some endangering human health or life safety. environment to complete various tasks.

In various operations of human beings, the arms and hands are generally relied on to complete complex operation tasks. At present, a common method for teleoperation of the arm is to design an arm mechanism that is isomorphic to the robot arm, and the arm mechanism is placed beside or set on the operator's arm. The operator wears the arm mechanism to operate. The system extracts the operation data of the arm mechanism to control the robot arm to complete the teleoperation operation. Such an arm mechanism mainly has the following disadvantages:

1. Due to the influence of the gravity of the arm mechanism, it brings inconvenience to the operation. In order to complete the operation during the operation, the operator needs to apply external force to the arm to overcome the gravity to maintain its operating position, which is not convenient for long-term operation; after the operator removes the external force, the arm returns to the natural drooping state due to the effect of gravity. The operating position cannot be maintained, which is inconvenient for continuous operation.

2. The length of the arm mechanism is fixed, and it is difficult to adapt to the needs of different arm lengths of different operators. Since the arm lengths of natural people are different, the teleoperation arm mechanism with a fixed mechanism length may not match the size when worn on the arms of different operators, making it difficult to achieve precise operation.

Invention content:

In order to solve the problem that the gravity of the teleoperation arm mechanism affects the operation and the adaptability to different operators, and make the teleoperation arm convenient to operate and adapt to operators with different arm lengths, the present invention provides an arm mechanism with a series structure, A 6-DOF teleoperated data arm with gravity compensation and adjustable length.

The technical scheme adopted in the present invention is: the data arm mechanism of the present invention is a mechanical arm with 6 rotating joints, each rotating joint is equipped with a potentiometer as an angle sensor, and the rotational position of the joint is equal to the rotation angle of the potentiometer. correspond. The data arm is worn on the operator's right arm and can perform stretching, shrinking, lifting, and releasing movements in three directions: front, back, and right. The axis of the arm rotates; in order to allow people with different arm lengths to wear this arm controller, a length-adjustable device is designed in the center of the arm tube of the upper arm and the forearm respectively, and there are 5 levels of arm length to choose from. Adjust the arm length by changing the threaded hole corresponding to the screw. The length of the upper arm can be selected from 285mm to 245mm, with a difference of 10mm in each step; the length of the forearm can be selected from 240mm to 200mm, with a difference of 10mm in each step. It can be worn by people with a height range of about 150cm-180cm. The rubber O-ring is used to increase the friction at the joint rotation, so that the arm does not need the support of people or other objects when it stays at any position, and will not slip without authorization.

Description of drawings:

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

Fig. 1 is a perspective view of the data arm mechanism of the present invention.

Fig. 2 is a telescopic structure diagram of the boom and the forearm of the present invention.

Fig. 3 is a structural diagram of the revolving pair 2A

Figure 4 is a schematic diagram of the positioning mechanism

Fig. 5 is the sectional view of the structural form 2 of the joint of the present invention

In the figure: 1-shoulder. 2A\2B\2C-rotating joint. 3A\3B\3C-rotating joint. 4A\4B-commutator. 5A\5B-intermediate section.6-big arm.7-small arm. 8-hand claw.9-potentiometer.10-coupling.11-fixing nut.12-locking sleeve.13-spindle.14-washer.15-variable shaft seat.16-"O" ring. 17-Friction disc.18-Reversing disc.19A\19B-Setting screw.20-Nut.21-Washer.22-Top wire.23-Rolling bearing.24-Cover.25-Change shaft seat.

The present invention will be further described below in conjunction with accompanying drawing:

The six degrees of freedom of the arm are realized by two revolving joints respectively. Number 1 in the figure is the shoulder of the data arm, which is connected with a revolving pair 2A. The rotary joint 2A can realize the forward and backward swing of the shoulder joint. The swivel pair 3A is connected with the swivel pair 2A to realize the left and right swing of the shoulder joint. The specific working process of the rotary pair 2A and the rotary pair 3A will be introduced below. The commutator 4A is used to realize the connection between the swivel joint 3A and the forearm.

The function of the rotation of the boom 6 around the axis of the arm translates to the elbow, which is realized by another swivel pair 2B. The rotating joint 3B connected with it realizes the flexion function of the elbow of the arm. Also use the commutator 4B to realize the connection between the elbow joint and the forearm 7 . The rotation of the forearm 7 is realized by the third rotation pair 2C connected with the forearm 7, and the third rotation pair 3C is used to realize the up and down rotation of the wrist.

The middle section 5A of the part above the elbow joint and the big arm 6 together form a telescopic big arm; the middle section 5B and the forearm 7 of the part below the elbow joint together form a telescopic forearm. The big arm 6 and the small arm 7 have the same structure. According to the different arm lengths of people, there are different lengths. The telescopic principle of the big arm 6 is shown in FIG. 2 .

There are five parallel screw holes on both sides of the middle section 5A, each with a distance of 10 mm. A hexagon socket screw is also fixed in the middle of its front for positioning. The bayonet of the big arm 6 is inserted against the position of the inner hexagonal screw in the middle, and there is a through hole on both sides of the bayonet, which can correspond to two screw holes of the middle section 5A according to different insertion depths. If you want to adjust the arm length of the teleoperation arm arm, just remove the screws on both sides, lengthen or shorten the insertion depth of the middle section, so that the through holes on both sides of the bayonet correspond to another row of screw holes. Like this, boom 6 has the arm length that five gears can be selected. The structure of the small arm 7 is the same as that of the large arm 6, and the adjustment principle is also the same. In the present invention, the length of the boom 6 is selectable from 285mm to 245mm, with a difference of 10mm in each gear; the length of the small arm 7 is selectable from 240mm to 200mm, with a difference of 10mm in each gear. According to the laws of human body structure, upper limbs: height ≈ 0.452; upper arm + forearm: height ≈ 0.296. This arm controller can be worn by people whose height ranges from about 150cm to 180cm.

FIG. 3 is a sectional view of the mechanical structure of the revolving pair 2A. The fixing nut 11 (see FIG. 5 ) of the potentiometer 9 in the figure fixes the potentiometer 9 , the locking sleeve 12 and the shaft coupling 10 together. The detection shaft of the potentiometer 9 is fixed on the main shaft 13 by the jackscrew 22, because the detection shaft of the potentiometer cannot bear too much weight and torque, so the rolling bearing 23 is used to reduce friction and bear the load at the external relative rotation of the main shaft. One end of the reversing disc 18 is connected to the arm pipe, and the other end is fixed on the main shaft 13 by a nut 20 . The rotation angle of the joint is transmitted to the main shaft 13 through the commutation disc 18, and then transmitted to the potentiometer detection shaft by the main shaft 13, and the task of angle detection is completed. Among the figure, the variable shaft seat 15 is a receiving part, which is responsible for linking to each other with the upper stage transmission arm.

The rubber "O" ring 16 is a device used to increase the friction between the fixed end and the rotating end. It can also be a friction plate or other devices that adjust the size of the friction force depending on the degree of compression. The friction disc 17 in Fig. 3 is used to compress the rubber "O" ring 16, and can be directly screwed from the outside after installation. Before use, when adjusting the thread stroke of the friction disc 17 on the reversing disc 18, it is advisable to reach the degree that the arm can stay in any position, but can not slip without authorization.

A limiting device is also designed between the fixed part and the rotating part of the rotating pair 2A. As shown in Figure 4, there are two positioning screws 19A on the variable shaft seat 15, and one positioning screw 19B on the reversing disc 18. These three screws have the same distribution radius and are distributed in different positions according to the positioning requirements of the rotation angle. . When the reversing disc 18 is pressed on the main shaft 13 by the nut 20 , the set screw 19B is just located between the two set screws on the variable shaft seat 15 . Like this, when reversing disc 18 rotates to certain position, when the positioning screw on it collides with one direction on the variable shaft seat 15, it reaches a position limit, and reversely obtains another position limit.

In order to meet the measurement requirements, it is necessary to align one position limit of the commutation disc 18 with the zero rotation angle position of the potentiometer detection shaft during installation, and make the potentiometer detection value gradually increase when it turns to another position limit.

During work, when the commutator 4 fixed on the arm tube drives the commutator disc 18 to rotate, the main shaft 13 will rotate in the same direction under the pressing force of the nut 20 and the washer 21 . This rotation is transmitted to the detection shaft of the potentiometer under the action of the top wire 22 so as to detect the corresponding rotation angle. Under the action of the limiting device, the reversing disc 18 can only rotate within a certain angle range, and there will be no multiple solutions in the change from one position to another.

FIG. 5 is a cross-sectional view of the mechanical structure of the revolving pair 3A. Its principle of motion is the same as that of the revolving pair 2A, except that the cover 24 is used to replace the variable shaft seat 15, and the connecting disc 25 is used to replace the reversing disc 18 to facilitate the connection with the hollow cylindrical arm tube of the arm. What is different during work is that the arm tube drives the connection plate 25 to drive the main shaft and transmit it to the potentiometer detection shaft.

The beneficial effects of the present invention are:

1. Light weight. The weight of the data arm mechanism manufactured according to the present invention is 995 grams in total, and it can detect degrees of freedom in six directions of shoulder joint, elbow joint and wrist joint.

2. Strong adaptability. The present invention can be suitable for wearing by people with different arm lengths. The rotation angle of each joint is detected by the angle sensor and can be used for teleoperation of the robot.

3. Easy to operate. The arm-hand controller can guide the movement when someone is wearing it, and can also pull it to the desired state without wearing it, and does not require external force assistance when pausing at any position.

Detailed ways:

First: before the operation starts, the shoulder 1 of the data arm mechanism will be fixed on the operation platform, and the friction discs 17 of each rotary joint will be rotated to adjust the friction to an appropriate level.

Second: adjust the length of the big arm 6 and the small arm 7 of the data arm mechanism according to the operator's arm length.

Third: Keep the big arm 6 of the operator's right arm straight, the small arm 7 stretched flat, and the palm of the hand is stretched flat to the left. The angle between the big arm 6 and the small arm 7 is 90 degrees. Place the operator's shoulders under shoulder 1 of the data arm mechanism. The big arm 6 of the data arm mechanism is on the right side of the operator's big arm; and the operator's wrist joint is above the data arm mechanism wrist joint.

The 4th, the operator's shoulder, arm, hand, and fingers are respectively fixed with the corresponding parts of the data arm mechanism with sticky hooks.

Fifth, start the system and start working.

Claims (3)

1. A data arm mechanism for remote operation of a humanoid robot arm, which can be worn on a human arm for motion extraction. It is characterized in that: the arm mechanism is a series structure with 6 rotating joints, and has the same characteristics as the analog The humanoid robot arm has similar 6 degrees of freedom; each rotary joint is equipped with a potentiometer as an angle sensor, the length of the data arm mechanism is adjustable, and there is gravity compensation between joint rotations. 2. The data arm mechanism according to claim 1, characterized in that: a rubber O-ring is installed between the rotating parts, and the degree of compression of the rubber O-ring is used to adjust the friction force, so as to realize the gravity compensation of the arm's own weight , so that the data arm can guide the movement when the operator wears it, and can also pull it to the required state without wearing it, and does not require external force assistance when pausing at any position. 3. The data arm mechanism according to claim 1, characterized in that: each section of the arm tube has five adjustable lengths, and the arm length can be adjusted by changing the threaded hole corresponding to the screw, which is suitable for people with different arm lengths to wear.

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