Hollow mechanical wrist joint capable of being mechanically and reversely driven and mechanical arm

Abstract

The invention discloses a hollow mechanical wrist joint capable of being mechanically driven reversely and a mechanical arm. The hollow mechanical wrist joint and the mechanical arm are used for achieving function simulation of a core mechanical joint. Comprising a hollow first frame body and a hollow second frame body which are connected with each other through a second rotating shaft, the first frame body is connected with a first rotating shaft, and four driving devices are arranged on the second frame body and drive the first frame body to rotate left and right around the first rotating shaft and drive the second frame body to rotate left and right around the second rotating shaft. The mechanical wrist joint is simple and compact in structure, the interior of the mechanical wrist joint is hollow, arrangement of connecting pieces is facilitated, the mechanical wrist joint can be driven reversely, the safety of man-machine interaction is improved, and the simulation function of the mechanical wrist joint is achieved more comprehensively.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent robots, and in particular to a hollow mechanical reversibly drivable mechanical wrist joint and a mechanical arm. Background Art

[0002] Humanoid robots and industrial robots have different requirements for mechanical joints. For example, the end effector of traditional industrial robots is very simple, and the reverse rotation is in a mechanical self-locking state to ensure the rigidity and precision of industrial robots. The movement of its mechanical joints - wrists is mostly achieved by direct drive in series or bevel gear differential mechanisms. The overall size is not compact and is far from the humanoid wrist. The mechanical joint movement mechanism of humanoid robots must be compact to imitate human joint movement; at the same time, it must have a mechanical reverse drive function to ensure the safety of human-machine interaction; and the mechanical joints must remain hollow to leave space for the internal channels of the joints for sensing, control, and power transmission of the dexterous fingers, palms, and other parts connected to the front end of the mechanical joints.

[0003] Due to the humanoid shape and functional requirements of the humanoid robot, the degree of freedom of the two arms can be close to 60. Such a large number of joint degrees of freedom requires a drive device such as a motor, which is very difficult to arrange in physical space. At the same time, sensing, control, and power transmission also interfere with each other in space, and the arrangement must be coordinated with the movement of the robot arm, and the difficulty cannot be ignored. Therefore, when designing and selecting the drive system, it is necessary to minimize and simplify it. When the mechanically reversible arm system interacts with humans, it is not easy to hurt people in the event of accidental operation. When humans interact with this type of robot arm, the safety factor is higher.

[0004] In the field of humanoid robots, the core mechanical joints are different from the five finger drives, such as the wrist mechanism, neck mechanism, ankle mechanism, etc., which all require mechanical reversible drive for multi-angle spatial rotation in a compact space. In addition to taking into account the hollowness of the mechanism design, the drive of this type of core mechanical joint must also take into account the human-shaped compactness of the mechanism, greater load-bearing capacity, precision and rigidity, and mechanical reverse drive to ensure the safety of human-machine interaction in various situations. The mechanical wrist joint developed by KoreaTech is not hollow inside, has a complex structure, and has a large number of rigid bodies in the spatial motion mechanism, which is not conducive to the arrangement of the connecting parts of each drive and the individual enhancement of the rigidity and precision of the mechanical joint. The mechanical wrist joint of Tesla is semi-hollow inside, using a roller screw plus a motor drive. The joint cannot be mechanically reverse driven, which is also not conducive to the arrangement of the connecting parts of each drive and the safety during operation. The mechanical joint of the German Aerospace Agency has a complex and large number of rigid bodies to achieve the spatial rotation structure, which is not conducive to improving the strength and rigidity of the mechanical joint.

[0005] At present, the design of the core mechanical wrist joint of a humanoid robot needs to be hollow inside, mechanically reversibly driven, and compact and simple in structure, so as to better meet the passage and arrangement of the connecting parts, leave space for separately enhancing the stiffness and precision of the mechanical wrist joint, and improve the safety factor during human-computer interaction, so as to better simulate the functions of various key joints of a human. Summary of the invention

[0006] The embodiment of the present invention provides a hollow mechanically reversibly drivable mechanical wrist joint, which simultaneously realizes internal hollowness, mechanical reversible drivability, and a compact and simple structure, better meets the passage and arrangement of connecting parts in the mechanical wrist joint, provides enhanced space for separately enhancing the stiffness and precision of the mechanical wrist joint, and improves the safety factor during human-computer interaction, thereby better simulating the functions of various key joints of humans.

[0007] An embodiment of the present invention provides a hollow mechanical reversibly drivable mechanical wrist joint, comprising: A hollow first frame and a hollow second frame, the first frame and the second frame are connected to each other; The tail of the first frame is connected to the first rotating shaft, and the first frame rotates around the first rotating shaft; the front end of the first frame is connected to the tail of the second frame through the second rotating shaft, and the second frame rotates around the second rotating shaft; The axis of the first rotating shaft is perpendicular to the axis of the second rotating shaft or the spatial angle between them is close to 90 degrees; The first rotating shaft and the second rotating shaft divide the front end space of the second frame into four directional driving parts, and a driving device is respectively provided in each directional driving part; Driven by the drive device, the following are achieved: a) The first frame rotates left and right around the first rotation axis; or b) the second frame rotates left and right around the second rotation axis; or c) The first frame and the second frame rotate left and right around their respective rotation axes simultaneously.

[0008] The frame can rotate left and right when driven by a driving device, realizing mechanical forward and reverse drive, which is different from the existing mechanical joints that can only rotate mechanically in a single direction when driven by a driving device.

[0009] In a preferred embodiment, the end shapes of the first frame body and the second frame body are circular, elliptical, square or irregular arc shapes.

[0010] In a preferred embodiment, when two driving devices on the same side of the rotating shaft rotate in the same direction, the first frame or the second frame is driven to rotate in the spatial direction where the two driving devices are located relative to the rotating shaft.

[0011] In a preferred embodiment, the driving devices are respectively arranged at the middle position of the wire diameter of the directional driving part.

[0012] A preferred implementation method of the driving device is a rope driving device, the fixed end of the rope is arranged on the direction driving part, and the driving motor is arranged on other components connected to the mechanical wrist joint. In specific implementation, the driving motor can be arranged at the rear end of the mechanical arm connected to the mechanical wrist joint or the back of the robot, and connected to the direction driving part through a rope.

[0013] A preferred embodiment further includes a connecting base, which is connected to the first frame through a first rotating shaft; pulleys are respectively arranged at the direction driving part and the corresponding position of the connecting base, forming four pulley groups respectively, and the driving device drives the first frame and the second frame to rotate respectively through the four pulley groups. The use of pulley groups can increase the driving force and reduce the angular velocity of the mechanical wrist joint when rotating, thereby improving the safety of human-computer interaction.

[0014] In a preferred embodiment, the driving device is a rope driving device, the rope fixed end is arranged at the direction driving part, the two ropes on the diagonal of the direction driving part respectively form a closed loop with tension, and are respectively connected to a driving device, and the first frame and the second frame are driven to rotate under the drive of the two driving devices. When the two driving devices drive the ropes of the two closed loops, a connecting base connected to the first frame through the first rotating shaft can also be provided. In this case, pulleys are respectively provided at the direction driving part and the corresponding connecting base positions to form two pulley block closed loops with tension, and are respectively connected to a driving device, and the first frame and the second frame are driven to rotate under the drive of the two driving devices.

[0015] The embodiment of the present invention further provides a mechanical arm, wherein the hollow mechanical reversibly drivable mechanical wrist joint of any of the above embodiments is connected to the mechanical arm. The rotation of the mechanical arm is an independent drive, which can be achieved by a rope plus a motor, or by a reducer plus a motor. The rotation drive of the mechanical arm can also maintain a certain amount of space inside to meet the needs of arranging the space through various connectors therein. Combined with the mechanical wrist joint, a hollow drive with three rotational degrees of freedom is realized.

[0016] The mechanical wrist joint and mechanical arm formed by the embodiments of the present invention simultaneously achieve internal hollowness, mechanical reversible drive, and compact and simple structure, and the direction rotation control is simpler and more reliable, which better meets the passage and arrangement of the connecting parts in the mechanical wrist joint, provides enhanced space for separately enhancing the stiffness and accuracy of the mechanical wrist joint, and improves the safety factor during human-computer interaction, thereby better simulating the functions of various key joints of humans. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1is a schematic diagram of a mechanical wrist joint according to an embodiment of the present invention; Figure 2 A schematic diagram of the driving direction of a mechanical wrist joint according to an embodiment of the present invention; Figure 3 A schematic top view of the driving direction of a mechanical wrist joint according to an embodiment of the present invention; Figure 4 Schematic diagram of a robotic arm according to an embodiment of the present invention. DETAILED DESCRIPTION

[0018] The following is combined with Figure 1 , a specific implementation of a hollow mechanical reversibly driven mechanical wrist joint provided by an embodiment of the present invention is described in detail. This mechanical wrist joint is generally used in core mechanical joints with a central conduction position, such as: wrist mechanism, shoulder joint, neck mechanism, ankle mechanism, etc.

[0019] An embodiment of the present invention provides a hollow mechanical reversibly drivable mechanical wrist joint, comprising: A hollow first frame body 1 and a hollow second frame body 2, wherein the first frame body 1 and the second frame body 2 are connected to each other; The tail of the first frame 1 is connected to the first rotating shaft 3, and the first frame 1 rotates around the first rotating shaft 3; the front end of the first frame 1 is connected to the tail of the second frame 2 through the second rotating shaft 4, and the second frame 2 rotates around the second rotating shaft 4; The axis of the first rotating shaft 3 is perpendicular to the axis of the second rotating shaft 4 or the spatial angle between them is close to 90 degrees; The first rotating shaft 3 and the second rotating shaft 4 divide the front end space of the second frame 2 into four directional driving parts 6, and a driving device 5 is respectively provided in each directional driving part 6; Under the drive of the driving device 5, the following are achieved: a) The first frame 1 rotates left and right around the first rotation axis 3; or b) the second frame 2 rotates left and right around the second rotation axis 4; or c) The first frame 1 and the second frame 2 rotate left and right around their respective rotation axes simultaneously.

[0020] The frame can rotate left and right when driven by a driving device, realizing mechanical forward and reverse drive. Unlike existing mechanical joints that can only rotate in a single direction when driven by a driving device, it is simpler and more convenient to control the rotation of the mechanical wrist joint.

[0021] The end shapes of the first frame 1 and the second frame 2 can be circular, elliptical, square or irregular arc. When the shape of the frame is implemented, the shape needs to be specifically determined according to the design of the connected mechanical arm, but the space in the middle needs to be maintained. The mechanical wrist joint is in a central conduction position, such as the front end connected to the manipulator, and the internal space needs to be arranged through various connectors connected to the fingers, such as: the traction rope of the rope drive, the electrical connection line and other physical lines. At the same time, when the mechanical wrist joint (wrist) is hollow, the line is arranged along the center line of the mechanical wrist joint. The length of the line is unchanged. Therefore, when various physical lines are arranged near the center line, the length of the line changes less, and it is easier to make a reasonable arrangement for a complex mechanical arm structure.

[0022] The driving devices 5 are respectively arranged at the middle position of the wire diameter of the direction driving part 6, and the four driving devices 5 form four driving directions that are diagonal to each other: a1 and a2, b1 and b2. At this time, the accuracy of the drive control is more accurate, less force is required, and it is also convenient for the arrangement of other physical lines passing through. Of course, it can also be set at other positions of the direction driving part 6. In this case, the complexity of the drive control will be increased. To drive the mechanical wrist joint to rotate, only two driving devices 5 in the same spatial direction need to operate in the same direction to realize the rotation of the mechanical wrist joint in the same spatial direction, that is, when the two driving devices on the same side of the shaft rotate in the same direction, they drive the first frame or the second frame to rotate in the spatial direction where the two driving devices are relative to the shaft. As Figure 3 The schematic diagram of the driving direction of the mechanical wrist joint shown in the top view, when viewed from above, the first rotating shaft 3 and the second rotating shaft 4 form four quadrants, each quadrant is the space where a driving device is located, when the driving devices on the same side of the first rotating shaft 3 drive in the same direction, the mechanical wrist joint rotates left and right; when the two driving devices on the same side of the second rotating shaft 4 drive in the same direction, the mechanical wrist joint rotates up and down. For example: if the mechanical wrist joint needs to rotate right, the driving device 5 in the direction of the upper right side a2 and the lower right side b2 can be tightened to drive the first frame 1 to rotate right; if the mechanical wrist joint needs to rotate upward, the driving device 5 in the direction of the lower left side a1 and the lower right side b2 can be tightened to drive the second frame 2 to rotate upward; if the mechanical wrist joint needs to rotate downward and left, the driving device 5 in the direction of the upper left side b1 and the upper right side a2 can be tightened to drive the second frame 2 to rotate downward, and at the same time, the driving device 5 in the direction of the lower left side a1 can be tightened to drive the first frame 1 to rotate left; similarly, rotation in other directions can be achieved, which are not listed here one by one.

[0023] like Figure 2As shown, in order to keep the mechanical wrist joint hollow, the preferred embodiment of the driving device 5 is a rope driving device, the rope fixed end is set at the direction driving part 6, and four rope fixed ends are formed corresponding to the driving direction: 5a1, 5a2, 5b1, 5b2, and the driving motor is set on other components connected to the mechanical wrist joint. In specific implementation, the driving motor can be set at the rear end of the mechanical arm connected to the mechanical wrist joint or the back of the robot, and connected to the direction driving part 6 through a rope. This arrangement can effectively reduce the dead weight of the mechanical wrist joint and the mechanical arm, and reduce the noise and vibration caused by the operation of the driving motor.

[0024] In a preferred embodiment, the mechanical wrist joint further includes a connecting base 7, and the connecting base 7 is connected to the first frame 1 via the first rotating shaft 3, so that the mechanical wrist joint can be more conveniently connected to the mechanical arm.

[0025] When the connecting base 7 is set, the setting of the driving device can be realized by a preferred embodiment. Pulleys are respectively set at the positions corresponding to the direction driving part 6 and the connecting base 7 in the four driving directions a1, a2, b1, and b2, respectively, to form four pulley groups in the four driving directions. The driving device drives the first frame and the second frame to rotate respectively through the four pulley groups, and the driving method is the same as the principle of the previous embodiment. The use of pulley groups can increase the driving force, while reducing the angular velocity of the mechanical wrist joint when rotating, and improve the safety during human-computer interaction.

[0026] The driving mode of the mechanical wrist joint of the present invention can also be two groups of closed-loop drives. In specific implementation, the driving device is a rope driving device, and the fixed end of the rope is set on the direction driving part 6. The two ropes on the diagonal of the direction driving part 6 respectively form a closed loop with tension, which can be driven by a planetary gear motor, a1 and a2 are a group (when a1 turns to a2, it is positive rotation), b1 and b2 are a group (when b1 turns to b2, it is positive rotation). There is a differential driving effect during driving, that is, when the two groups rotate in the same direction (the rotation directions of both groups are positive or reverse), the joint rotates left and right; when the two groups rotate in opposite directions (one group rotates forward and the other group rotates reversely), the joint rotates up and down. Driven by the two driving devices, the first frame 1 and the second frame 2 are driven to rotate. At this time, the function of the operation of 4 separate driving devices can be realized through the forward and reverse rotation of the driving device. Similarly, pulleys can be respectively provided on the connecting base 7 and the direction driving part 6 to form two closed loops of pulley groups with tension, and respectively connected to a driving device. Driven by the two driving devices, the two pulley groups drive the first frame 1 and the second frame 2 to rotate. At this time, the advantages of the pulley group design are also obtained.

[0027] like Figure 3As shown, an embodiment of the present invention further provides a robotic arm, in which the robotic wrist joint 11 of any of the above embodiments is connected to the robotic arm body 12. The rotation of the robotic arm body 12 is an independent drive, which can be achieved by a rope plus a motor, or by a reducer plus a motor. The rotation drive of the robotic arm body 12 can also maintain a certain amount of space inside to meet the various needs of arranging the space through the physical connectors therein. Combined with the robotic wrist joint 11, a hollow drive with three rotational degrees of freedom is realized.

[0028] The mechanical wrist joint and mechanical arm formed by the embodiments of the present invention simultaneously achieve internal hollowness, mechanical reversible drive, and compact and simple structure, and the direction rotation control is simpler and more reliable, which better meets the passage and arrangement of the connecting parts in the mechanical wrist joint, provides enhanced space for separately enhancing the stiffness and accuracy of the mechanical wrist joint, and improves the safety factor during human-computer interaction, thereby better simulating the functions of various key joints of humans.

[0029] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A hollow mechanical reversibly drivable mechanical wrist joint, characterized in that: It comprises a hollow first frame and a hollow second frame, wherein the first frame and the second frame are connected to each other; The tail of the first frame is connected to the first rotating shaft, and the first frame rotates around the first rotating shaft; the front end of the first frame is connected to the tail of the second frame through the second rotating shaft, and the second frame rotates around the second rotating shaft; The axis of the first rotating shaft is perpendicular to the axis of the second rotating shaft or the spatial angle between them is close to 90 degrees; The first rotating shaft and the second rotating shaft divide the front end space of the second frame into four directional drive parts, and a driving device is respectively provided in each directional drive part; Under the drive of the driving device, the following are achieved: a) the first frame rotates left and right around the first rotation axis; or b) the second frame rotates left and right around the second rotation axis; or c) The first frame and the second frame rotate left and right around their respective rotation axes simultaneously.

2. The mechanical wrist joint according to claim 1, characterized in that: The end shapes of the first frame body and the second frame body are circular, elliptical, square or irregular arc shapes.

3. The mechanical wrist joint according to claim 1, characterized in that: When the two driving devices on the same side of the rotating shaft rotate in the same direction, the first frame body or the second frame body is driven to rotate in the spatial direction where the two driving devices are relative to the rotating shaft.

4. The mechanical wrist joint according to claim 1, characterized in that: The driving devices are respectively arranged at the middle position of the wire diameter of the direction driving part.

5. The mechanical wrist joint according to claim 1, characterized in that: The driving device is a rope driving device, the rope fixed end is arranged on the direction driving part, and the driving motor is arranged on other components connected to the mechanical joint.

6. The mechanical wrist joint according to claim 1, 4 or 5, characterized in that: It also includes a connecting base, which is connected to the first frame through the first rotating shaft; pulleys are respectively arranged at the position of the direction driving part and the corresponding connecting base to form four sets of pulley groups, and the driving device drives the first frame and the second frame to rotate respectively through the four sets of pulley groups.

7. The mechanical wrist joint according to claim 1 or 4, characterized in that: The driving device is a rope driving device, the fixed end of the rope is arranged on the directional driving part, the two diagonal ropes of the directional driving part respectively form a closed loop with tension and are respectively connected to a driving device, and the first frame and the second frame are driven to rotate under the drive of the two driving devices.

8. The mechanical wrist joint according to claim 7, characterized in that: It also includes a connecting base, which is connected to the first frame through the first rotating shaft; pulleys are respectively arranged at the position of the direction driving part and the corresponding connecting base to form two closed loops of pulley groups with tension, and are respectively connected to a driving device, so as to drive the first frame and the second frame to rotate under the drive of the two driving devices.

9. A robotic arm, characterized in that: Comprising the mechanical wrist joint as described in any one of claims 1 to 8.

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