Metamorphic robot with remote central motion mode and Schnflies motion mode

Abstract

The invention discloses a metamorphic robot with a remote center motion mode and a # imgabs0 motion mode. The metamorphic robot comprises four mechanical arms and a motion module, wherein every two mechanical arms are connected through a rotation pair. The two ends of the first mechanical arm are connected with the second mechanical arm and the third mechanical arm through right-angle connecting pieces correspondingly. The motion module is installed in the fourth mechanical arm and comprises a spline lead screw shaft, a spline nut and a lead screw nut, wherein the spline nut and the lead screw nut are arranged on the spline lead screw shaft and connected with a lead screw pair in a sleeved mode through a spline pair. The end part of the spline lead screw shaft is provided with a flange connecting actuator; the spline and the lead screw nut are driven independently or simultaneously, so that the spline lead screw shaft can output two-degree-of-freedom movement of rotation and movement. Two ends of the fourth mechanical arm are respectively connected with the other ends of the second mechanical arm and the third mechanical arm through revolute pairs, so that the fourth mechanical arm has two-degree-of-freedom one-rotation and one-movement motion relative to the first mechanical arm; and finally, the whole metamorphic robot can realize two different motion modes of three-movement and one-rotation four-degree-of-freedom # imgabs1 # motion and three-rotation and one-movement four-degree-of-freedom remote center motion.

Description

Technical Field

[0001] The invention belongs to the field of robot technology and relates to a robot having remote central motion and Movement mode of the metamorphic robot. Background Art

[0002] Since the rigid body has only six degrees of freedom in motion in space, six-degree-of-freedom general-purpose robots have been widely used in the field of robotics, especially industrial robotics, such as PUMA and Stanford six-degree-of-freedom manipulators. However, for most tasks, the robot end-operator often does not need to have six degrees of freedom. Although the six-degree-of-freedom general-purpose robot can realize any movement with less than six degrees of freedom in space, the number of its degrees of freedom is greater than the actual required degrees of freedom, making the robot structure more complex; and when performing operations with less than six degrees of freedom, there is coupling between the movements of different drivers of the six-axis robot, which increases the difficulty of robot motion control. Therefore, robots with fewer degrees of freedom used for tasks with less than six degrees of freedom have also been widely studied and applied. The most typical cases are the three-shift one-turn four-degree-of-freedom SCARA robot widely used in industrial production for tasks such as plane handling and assembly, and the three-turn one-shift four-degree-of-freedom fixed-point operation Da Vinci robot used for minimally invasive surgery. Since the number of degrees of freedom of the above-mentioned robots is the same as the number of degrees of freedom required for the operation task, this type of robot has a compact structure, simple control, and fast dynamic response.

[0003] However, unlike the six-axis general-purpose robot, which can be applied to any operation task in space. Space robots with less than six degrees of freedom cannot cover all the movements of rigid bodies in space due to their motion modes, and cannot achieve a variety of different operation tasks like general-purpose six-axis robots, resulting in lower versatility than six-degree-of-freedom robots. Metamorphosis mechanisms and metamorphosis robots can achieve different operation modes through a set of mechanisms and drive devices, through their own structure and drive reorganization, so as to achieve multiple uses of one machine. Therefore, compared with the six-degree-of-freedom general-purpose robot, it has the advantages of simple structure, no redundant drive, simple motion control, etc. At the same time, compared with the traditional low-degree-of-freedom robot with only a single operation mode, it has higher versatility and adaptability for different operation tasks due to its variable operation mode. Therefore, metamorphosis robots have great application potential in the fields of multi-mode operation in unstructured environments, variable task operations in industrial production, and multi-mode operation in minimally invasive surgery. Summary of the invention

[0004] In view of the above problems, the present invention proposes a remote center movement and The mobile robot can achieve four degrees of freedom with three movements and one rotation through a set of mechanisms and drive devices. There are two different typical robot operations: the four-DOF motion mode and the three-turn and one-translation four-DOF remote center motion mode.

[0005] The present invention has a remote center movement and The motion mode metamorphic robot only needs four drive motors combined with joint limit design to achieve switching between two different four-degree-of-freedom operation tasks. No redundant drive is required when switching the operation mode, and the motion control is simple and reliable.

[0006] The present invention has remote center movement and A metamorphic robot with motion mode includes a first robotic arm, a second robotic arm, a third robotic arm, a fourth robotic arm and a motion module.

[0007] The first driving motor is installed at the front end of the first mechanical arm. The inner side surface of the first right-angle connector is arranged toward the first mechanical arm, and one side surface is fixedly connected to the output shaft of the first driving motor to form a rotation pair A. The outer side surface of the second right-angle connector is arranged toward the first mechanical arm, and one side surface is connected to the rear end of the first mechanical arm to form a rotation pair B. The other side surface of the first right-angle connector is connected to one end of the second mechanical arm to form a rotation pair C. The second driving motor is installed on the other side of the second right-angle connector, and the output shaft of the second driving motor is fixedly connected to one end of the third mechanical arm to form a rotation pair D. The other ends of the second and third mechanical arms are respectively connected to the front end and the end of the fourth mechanical arm to form a rotation pair E and a rotation pair F. The fourth mechanical arm has two degrees of freedom, one rotation and one translation, relative to the first mechanical arm; the above-mentioned motion pair E is designed with a mechanical limit.

[0008] A motion module is installed inside the fourth robotic arm; the motion module includes a spline screw shaft module and a driving mechanism. Among them, the spline screw shaft includes a spline screw shaft and a spline nut and a screw nut sleeved on it through a spline pair and a screw pair. The spline nut and the screw nut are driven by the driving mechanism to achieve individual or joint rotation. The front end of the spline screw shaft passes through the front end surface of the fourth robotic arm, and an actuator connecting flange is designed at the end. When the spline nut is driven to rotate alone, the spline screw shaft outputs spiral motion; when the screw nut is driven to rotate alone, the spline screw shaft outputs pure translational motion along the axial direction; when the spline nut and the screw nut are driven to rotate synchronously, the spline screw shaft outputs pure rotational motion, so that the spline screw shaft outputs a two-degree-of-freedom motion of one rotation and one translation. Combined with the two-degree-of-freedom one-rotation and one-translation motion of the aforementioned fourth robotic arm relative to the first robotic arm, a four-degree-of-freedom motion of the actuator connecting flange at the end of the spline screw shaft relative to the first robotic arm is obtained; the four-degree-of-freedom motion has two different forms, which respectively generate the robot's Motion and remote center motion operation modes, specifically:

[0009] When the robot is In the motion operation mode, the axis of the rotating pair A coincides with that of the rotating pair B, and the motion axes of the rotating pairs C, D, E and F are parallel to each other. At this time, the mechanical limit at the moving pair E does not contact; the spline screw shaft and its end actuator connection flange have the freedom of rotation relative to the fourth robot arm and translation along the rotation axis, and the rotation axis direction of the spline screw shaft is always parallel to the common axis direction of the rotating pair A and the rotating pair B. Therefore, the actuator connection flange at the end of the spline screw shaft in the fourth robot arm finally outputs a four-degree-of-freedom motion of 3 shifts and 1 rotation relative to the first robot arm, and the rotation direction during the movement is always parallel to the common axis direction of the rotating pair B and the rotating pair C, realizing Motion mode. In this motion mode, the robot's operating space is shaped like a hollow cylinder with the common axis of the revolute joint B and the revolute joint C as its axis.

[0010] When the robot moves from the aforementioned 3 to 1 When the motion mode moves to the motion bifurcation point, the motion axes of the revolving pairs D and E coincide, and the robot has two different motion mode tendencies; when the robot moves to the bifurcation position, the mechanical limit at the revolving pair E contacts, and when the second drive motor drives the revolving pair D to rotate clockwise, the counterclockwise rotation of the revolving pair E is restricted, making it impossible for the robot to continue to achieve In the motion mode, the motion axes of the revolving pair D and the revolving pair E remain coincident, and the revolving pair E will rotate clockwise along with the revolving pair D, thus entering the remote center motion mode of 3 rotations and 1 shift.

[0011] When the revolute pair E rotates clockwise following the revolute pair D, the mechanical limit at the kinematic pair E is released. At this time, the fourth robot arm has two rotational degrees of freedom relative to the first robot arm. The first rotation axis is the common axis of the revolute pairs A and B, and the second rotation axis is the coincident axis of the revolute pairs D and E. The two rotation axes are perpendicular and orthogonal to a point O. At the same time, the rotation axis of the spline screw shaft in the fourth robot arm will also intersect with the above two axes at point O; therefore, the motion mode of the actuator connection flange at the end of the robot and the end of the spline screw shaft is a combination of three-dimensional rotational motion around the common intersection point O of the three axes and translational motion along the direction of the third rotation axis, which is a 3-rotation 1-translation four-degree-of-freedom motion. In this motion mode, the robot's working space is a hollow sphere, and the center of the sphere is the common intersection point O of the three axes.

[0012] The advantages of the present invention are:

[0013] 1. The present invention has remote center movement and The mobile robot can achieve four degrees of freedom with three movements and one rotation through a set of mechanisms and drive devices. There are two different typical robot operations: the four-DOF motion mode and the three-turn and one-translation four-DOF remote center motion mode.

[0014] 2. The present invention has remote center movement and The motion mode metamorphic robot only needs four drive motors combined with joint limit design to achieve switching between two different four-degree-of-freedom operation tasks. No redundant drive is required when switching modes, and the motion control is simple and reliable.

[0015] 3. The present invention has remote center movement and The rotation and translation of the end arm of the metamorphic robot in motion mode are realized through a spline screw. The whole machine has a compact structure, high motion accuracy and reliability, and good dynamic response capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The present invention has remote center movement and Schematic diagram of the overall structure of the metamorphic robot in motion mode.

[0017] Figure 2 The present invention has remote center movement and Schematic diagram of the structure of the first robotic arm of the metamorphic robot in motion mode.

[0018] Figure 3 The present invention has remote center movement and Schematic diagram of the base structure of the first robotic arm of the metamorphic robot in motion mode.

[0019] Figure 4 The present invention has remote center movement and Schematic diagram of the first right-angle link structure of the metamorphic robot in motion mode.

[0020] Figure 5 The present invention has remote center movement and Schematic diagram of the second right-angle link structure of the metamorphic robot in motion mode.

[0021] Figure 6 The present invention has remote center movement and Schematic diagram of the structure of the second robotic arm of the metamorphic robot in motion mode.

[0022] Figure 7 The present invention has remote center movement and Schematic diagram of the structure of the third arm of the metamorphic robot in motion mode.

[0023] Figure 8 The present invention has remote center movement and Schematic diagram of the structure of the fourth robotic arm of the metamorphic robot in motion mode.

[0024] Fig. 9 The present invention has remote center movement and Schematic diagram of the structure of the 1-move-1-turn motion module of the metamorphic robot in motion mode.

[0025] Fig.10 The present invention has remote center movement and Schematic diagram of the structure of the spline screw module in the metamorphic robot with motion mode.

[0026] Fig.11 The present invention has remote center movement and Schematic diagram of the installation method of the spline screw module in the metamorphic robot with motion mode.

[0027] Fig.12 The present invention has remote center movement and The metamorphic robot in motion mode is Distribution diagram of the motion sub-axis in motion operation mode.

[0028] Fig.13 The present invention has remote center movement and The metamorphic robot in motion mode is Workspace diagram in motion operation mode.

[0029] Fig.14 The present invention has remote center movement and State diagram of the morphing robot when it is in different motion mode switching configurations.

[0030] Fig.15 The present invention has remote center movement and Distribution diagram of the motion sub-axes when the metamorphic robot is in remote center motion operation mode.

[0031] Fig.16 The present invention has remote center movement and Motion mode The workspace diagram of the metamorphic robot when it is in the remote center motion operation mode.

[0032] In the figure:

[0033] 1-First Robotic Arm 2-Second Robotic Arm 3-Third Robotic Arm

[0034] 4- fourth robot arm 5- first drive motor 6- second motor

[0035] 7-base box 8-first right angle connector 9-second right angle connector

[0036] 201-round hole A at the end of the second mechanical arm 202-round hole B at the end of the second mechanical arm 203-end protrusion

[0037] 301-round hole A at the end of the third mechanical arm 302-round hole B at the end of the third mechanical arm 303-radial threaded hole

[0038] 401- Robotic arm box 402- Motion module 401a- Upper part of the box

[0039] 401b-lower half of the box 401c-left rear round hole 401d-cylindrical joint

[0040] 401e-right front round hole 401f-arc-shaped recess 401g-upper connecting plate A

[0041] 401h-upper connecting plate B 401i-lower connecting plate A 401j-lower connecting plate B

[0042] 401k- positioning groove 401m- connecting plate shaft hole A 401n- connecting plate shaft hole B

[0043] 401p-upper connecting shoulder 401q-lower connecting shoulder 402a-spline screw module

[0044] 402b-Spline nut drive motor 402c-Screw nut drive motor 402d-Drive pulley A

[0045] 402e-driven pulley A 402f-driving pulley B 402g-driven pulley B

[0046] 402h-synchronous belt 402i-actuator connection flange 402a1-spline screw shaft

[0047] 402a2-Spline nut 402a3-Screw nut 402a4-Connection hole A

[0048] 402a5-Connection threaded hole A 402a6-Connection hole B 402a7-Connection threaded hole B

[0049] 701-upper part of the base box 702-lower part of the base box 703-large round hole of the base box

[0050] 704- small round hole of base box 705- axial hole of base box 801- round hole of first boss

[0051] 802-first boss threaded hole 803-first through hole 804-first circular boss

[0052] 901-second boss circular hole 902-peripheral circular hole 903-second through hole DETAILED DESCRIPTION

[0053] The present invention will be further described below in conjunction with the accompanying drawings.

[0054] like Figure 1 As shown, the present invention has remote center movement and The metamorphic robot in motion mode is mainly composed of four robotic arms, including a first robotic arm 1, a second robotic arm 2, a third robotic arm 3 and a fourth robotic arm 4. Different robotic arms are articulated by revolute pairs and driven by joint motors.

[0055] The structure of the first mechanical arm 1 is as follows Figure 2 As shown, the first robot arm 1 is composed of a first drive motor 5, a second drive motor 6, a base box 7, a first right-angle connector 8 and a second right-angle connector 9.

[0056] Among them, the base box 7 is composed of an upper part 701 of the base box and a lower part 702 of the base box; the cross-sections of the upper part 701 of the base box and the lower part 702 of the base box are both U-shaped, and shoulders are designed at the edges of the left and right sides of the two sides along the front-to-back direction, and through holes are evenly distributed on the shoulders along the front-to-back direction; the upper part 701 of the base box and the lower part 702 of the base box are fixed to each other by tightening the bolts with the through holes at the corresponding positions on the shoulders on both sides of the upper part 701 of the base box and the lower part 702 of the base box, so as to form a base box 7 with an overall rectangular cross-section, such as Figure 3 As shown. A large circular hole 703 is provided at the center of the front end face of the base box 7. Four small circular holes 704 are provided around the large circular hole 703, which are respectively located at the four circumferential corners of the front side of the base box 7 for installing the first drive motor 5. A base box shaft hole 705 is provided at the rear end face of the base box 7. The base box shaft hole 705 is coaxial with the large circular hole 703 of the base box and is used to connect the first right-angle connector 8. A connecting through hole is also provided on the side wall of the base box 7 for mounting and positioning the metamorphic robot of the present invention with screws.

[0057] The first drive motor 5 is located inside the base box 7, and its output shaft passes through the front end surface of the base box 7 through the large circular hole 703 of the base. At the same time, the first drive motor 5 is connected and fixed to the front end surface of the base box 7 by screws at four small circular holes 704 of the base box.

[0058] The first right-angle connecting member 8 is a right-angle plate-shaped structure having two mutually perpendicular side surfaces and a bottom surface, such as Figure 4 As shown. A first through hole 803 is formed on the side surface of the first right-angle connector 8, a first circular boss 804 is designed on the inner side of the bottom surface, and a first boss circular hole 801 is formed in the center of the first circular boss 804 along the axial direction; the axis of the first boss circular hole 801 is perpendicular to the axis of the first through hole 803 on the side surface at 90°. At the same time, a first boss threaded hole 802 is formed on the first circular boss 804 along its radial direction, and the axis of the first boss threaded hole 802 is perpendicular to the axis of the first boss circular hole 801 at 90°.

[0059] The structure of the second right-angle connector 9 is similar to that of the first right-angle connector 8, and also has two mutually perpendicular side surfaces and a bottom surface. Figure 5 As shown. A second circular boss 904 is designed on the inner side of the side of the second right-angle connector 9, and a second boss circular hole 901 is radially opened at the center of the second circular boss 904; at the same time, four peripheral circular holes 902 are evenly distributed around the periphery of the second circular boss 904. A second through hole 903 is opened on the bottom surface of the second right-angle connector 9, and its axis is also perpendicular to the axis of the second center circular hole 901 at 90°.

[0060] The inner side surface of the bottom surface of the above-mentioned first right-angle connecting member 8 is arranged toward the front end surface of the first robotic arm 1, and the first boss circular hole 801 on the bottom surface is plugged into and fitted with the output shaft of the first driving motor 5, and is tightened and fixed by a top screw threadedly installed in the first boss threaded hole 802, forming a rotating pair A.

[0061] The outer side surface of the bottom surface of the second right-angle connector 9 is arranged toward the rear end surface of the first mechanical arm 1, and the second circular hole 903 on the bottom surface is connected to the base box shaft hole 705 at the rear end center of the base box 7 through a pin shaft, forming a rotation pair B. The second drive motor 6 is arranged on the outer wall of the side surface of the second right-angle connector 9; the output shaft of the second drive motor 6 passes through the second center circular hole 901 on the side surface of the second right-angle connector 9; and the second drive motor 6 is fixed to the side surface of the second right-angle connector 9 by screws at the four peripheral circular holes 902 on the side surface of the second right-angle connector 9.

[0062] like Figure 6 The second mechanical arm 2 is a straight rod, the opposite sides are parallel planes, and the two ends are arc structures. The second mechanical arm 2 is provided with a second mechanical arm end circular hole A201 and a second mechanical arm end circular hole B202 at both ends, and the axes of the two are parallel and perpendicular to the side of the straight rod. Among them, an end protrusion 203 is designed on the side wall surface of one end where the second mechanical arm end circular hole B202 is located. The end protrusion 203 is a fan-shaped structure, the inner arc is connected to the second mechanical arm end circular hole B202, and the outer arc is connected to the straight rod end circular arc.

[0063] The structure of the third robotic arm 3 is similar to that of the second robotic arm 2, and the difference between the two is that the end of the third robotic arm 3 where the circular hole B302 is located does not have an end protrusion structure; instead, a radial threaded hole 303 is opened at the end where the circular hole A301 is located, and the axis of the radial threaded hole 303 is along the radial direction of the circular hole A301 at the end of the third robotic arm and is perpendicular to the axis of the third robotic arm 3.

[0064] The second mechanical arm end circular hole A201 on the second mechanical arm 2 is connected to the first through hole 803 on the side of the first right-angle connector 8 via a pin shaft to form a revolute pair C. The third mechanical arm end circular hole A301 on the third mechanical arm 3 is plugged with the output shaft of the second drive motor 6 and is fixed by a top screw installed in the radial threaded hole 303 of the second mechanical arm to form a revolute pair D.

[0065] The fourth robot arm 4 includes a robot arm housing 401 and a motion module 402. Figure 8 As shown. Among them, the robot box 401 is assembled by the upper half 401a of the box and the lower half 401b of the box, and the connection method of the two parts of the box is the same as that of the base box 7. A semicircular groove is designed at the corresponding position of the edge where the upper half 401a of the box and the rear end of the left side of the lower half 401b of the box meet, so that a left rear side circular hole 401c is formed at the rear end of the left side wall of the robot box 401 after assembly. A semi-cylindrical joint is designed at the edge where the upper half 401a of the box and the front end of the right side of the lower half 401b of the box meet, and a semi-circular groove is coaxially opened on the semi-cylindrical joint, and an arc-shaped recess is also designed along the outer circumference on the outer end surface of the semi-cylindrical joint, so that a cylindrical joint 401d, a coaxial right front side circular hole 401e on the cylindrical joint 401d, and an arc-shaped recess 401f on the outer end surface of the cylindrical joint 401d are formed at the front end position of the right side of the robot box 401 after assembly. A semicircular groove is designed in the middle of the connecting edge between the front end surfaces of the upper half 401a and the lower half 401b of the box body, so that a circular shaft hole is formed at the center of the front end surface of the robot arm box body 401 after assembly.

[0066] like Fig. 9 As shown, the motion module 402 is installed inside the fourth robot arm 4, including a spline screw module 402a, a spline nut drive motor 402b, a screw nut drive motor 402c, a driving pulley A402d, a driven pulley A402e, a driving pulley B402f, a driven pulley B402g, a synchronous belt 402h and an actuator connecting flange 402i.

[0067] Among them, the structure of the spline screw module 402a is as follows Fig.10 As shown, it includes a spline screw shaft 402a1 and a spline nut 402a2 and a screw nut 402a3 connected to the spline screw shaft 402a1 through a spline sleeve, and the two respectively form a spline pair and a screw pair with the spline screw shaft 402a1. Among them, the outer side of the spline nut 402a2 is connected to a flange through a bearing sleeve, and the flange has six connection holes A402a4 evenly distributed on the circumference; at the same time, the rear end surface of the spline nut 402a2 has four connection threaded holes A402a5 evenly distributed on the circumference. The outer side of the screw nut 402a3 is connected to a flange through a bearing sleeve, and the flange has six connection holes B402a6 evenly distributed on the circumference; the front end surface of the nut has four connection threaded holes B402a7 evenly distributed on the circumference.

[0068] The above-mentioned spline screw shaft 402a1 is connected to the robot arm box 401 through the spline nut 402a2 and the outer flange of the screw nut 402a3; wherein, the upper and lower halves of the spline nut 402a2 are respectively placed in the positioning groove 401k opened at the connection position between the upper connecting plate A401g and the lower connecting plate A401i designed in the lower half 401b of the box, and are fixed to the upper connecting plate A401g and the lower connecting plate A401i by screws through the six connecting holes A402a4 on the flange, as shown in FIG. Fig.11 Similarly, the upper and lower halves of the lead screw nut 402a3 are respectively placed in the positioning groove 401k opened at the joint position of the upper connecting plate B401h and the lower connecting plate B401j designed in the lower half 401b of the box body, and are fixed to the upper connecting plate B401h and the lower connecting plate B401j by screws through the six connecting holes B402a6 on the flange.

[0069] The spline nut 402a2 and the lead screw nut 402a3 are driven by the spline nut driving motor 402b and the lead screw nut driving motor 402c. Fig. 9 As shown. The spline nut driving motor 402b is fixed to the upper connecting plate A401g by screws, and the output shaft passes through the connecting plate shaft hole A401m opened above the upper connecting plate A401g, and is coaxially fixed to the driving pulley A402d by a top screw; the driving pulley A402d is sleeved with the driven pulley A402e through the synchronous belt 402h, and the driven pulley A402e is sleeved on the spline screw shaft 402a1, and is fixed with the connecting threaded hole A402a5 on the rear end surface of the spline nut 402a2 by screws. Therefore, the motion output by the rotating shaft of the spline nut driving motor 402b can be transmitted to the spline nut 402a2 through the driving pulley A402d, the synchronous belt 402h and the driven pulley A402e.

[0070] The lead screw nut driving motor 401b is fixed to the upper connecting plate B401h by screws, and the output shaft passes through the connecting plate shaft hole A401n opened on the upper side, and is coaxially fixed to the driving pulley B402f by a top screw; the driving pulley B402f is sleeved with the driven pulley B402g through the synchronous belt 402h, and the driven pulley B402g is sleeved on the spline lead screw shaft 402a1, and is screwed with the connecting threaded hole B402a7 on the front end face of the lead screw nut 402a3 to achieve the connection between the driven pulley B402g and the lead screw nut 402a3. Therefore, the motion output by the rotating shaft of the lead screw nut driving motor 401c is transmitted to the lead screw nut 402a3 through the driving pulley B402g, the synchronous belt 402h and the driven pulley B402g.

[0071] The upper connecting plate A401g and the upper connecting plate B401h are also fixed by bolts through the upper connecting shoulders 401p designed on the side walls at both ends of their bottom edges and the lower connecting shoulders 401q designed on both sides of the inner wall of the lower half 401b of the box body. After the installation of the above-mentioned spline screw shaft 402, the upper half box body 401a can be installed so that the two upper connecting plates are located in the upper half box body 401a, and the upper and lower parts of the box body are further connected and fixed by bolts.

[0072] The front end of the spline screw shaft 402a1 passes through the circular shaft hole at the front end of the robot box 401, and the end is installed with an actuator connection flange 402i for connecting an actuator, such as a clamping hand, etc. The output motion and motor drive mode of the spline screw shaft 402a1 are:

[0073] When the spline nut driving motor 402b drives the spline nut 402a2 to rotate, and the spline nut driving motor 402c does not drive the lead screw nut 402a2, the spline lead screw shaft 402a1 outputs spiral motion; when the lead screw nut driving motor 402c drives the lead screw nut 402a3 to rotate, and the spline nut driving motor 402b does not drive the spline nut 402a2, the spline lead screw shaft 402a1 outputs pure translational motion along the axial direction. When the spline nut driving motor 402b drives the spline nut 402a2 to rotate, and the lead screw nut driving motor 402c drives the lead screw nut 402a3 to rotate at the same angular velocity, the spline lead screw shaft 402a1 outputs pure rotational motion. It can be seen that the motion module 402 can enable the spline lead screw shaft 402 to output a two-degree-of-freedom motion of one rotation and one translation through different driving modes.

[0074] The fourth mechanical arm 4 of the above structure is connected to the third mechanical arm end circular hole B302 of the third mechanical arm 3 through the left rear circular hole 401c at the rear end of the left wall of the mechanical arm box 401 through a pin shaft, forming a revolute pair F. At the same time, the right front circular hole 401e at the front end of the right side of the mechanical arm box 401 is connected to the second mechanical arm end circular hole B202 of the second mechanical arm 3 through a pin shaft, forming a revolute pair E; at the same time, the end protrusion 203 on the second mechanical arm 2 is embedded in the arc-shaped recess 401f on the outer end surface of the cylindrical joint at the front end of the right side of the mechanical arm box 401, forming the mechanical limit of the revolute pair E.

[0075] The lengths of the first mechanical arm 1, the second mechanical arm 2, the third mechanical arm 3 and the fourth mechanical arm 4 are all equal. The first mechanical arm 1, the second mechanical arm 2, the third mechanical arm 3 and the fourth mechanical arm 4 are connected by a revolute pair AF and two right-angle connectors to form a 6R mechanism; so that the fourth mechanical arm 4 has two degrees of freedom relative to the first mechanical arm 1, one rotation and one translation.

[0076] The aforementioned two-degree-of-freedom motion of one rotation and one translation output by the spline screw shaft 402a is combined with the two-degree-of-freedom one rotation and one translation motion of the fourth robot arm 4 relative to the first robot arm 1, and finally a four-degree-of-freedom motion of the end effector connecting flange 402i of the spline screw shaft 402a relative to the first robot arm 1 can be generated. Through the different geometric relationship configurations between the robot joints of the present invention, the four-degree-of-freedom motion has two different forms, which respectively generate the robot's Sports mode and remote center sports mode, specifically:

[0077] The robot is The movement joints are arranged as follows during the movement mode: Fig.12 As shown. In this joint configuration, the axes of the revolute pair A and the revolute pair B coincide, and the axes of motion of the revolute pairs C, D, E and F are parallel to each other. For the kinematic pair E, the mechanical limit and no contact occur at this time, which will not restrict the movement of the robot. As mentioned above, the spline screw shaft 402a and its end effector connection flange 402i have the freedom of rotation relative to the fourth robot arm 4 and translation along the axis of rotation, and as Fig.12 The joint arrangement shown in the figure shows that the rotation axis direction of the spline screw shaft 402a is always parallel to the common axis direction of the revolute pair A and the revolute pair B during the robot movement. Through kinematic analysis, it can be obtained that the final motion output by the front end actuator connection flange 402i of the spline screw shaft 402a in the fourth robot arm 4 relative to the base box 7 is a four-degree-of-freedom motion of 3 displacements and 1 rotation, and the rotation direction during the motion is always parallel to the common axis direction of the revolute pair A and the revolute pair B. The operation space of the robot in this motion mode is as follows Fig.13 As shown, its shape is a hollow cylinder 10 with the common axis of the revolute pair A and the revolute pair B as the axis. The actuator connection flange 402i at the end of the robot can move three-dimensionally in the cylindrical space 10 and realize rotational movement along the axis direction of the cylinder 10 at any position, realizing Movement mode: This movement mode is the same as the SCARA robot widely used in industrial production and assembly, and is very suitable for operations such as plane handling and assembly of workpieces.

[0078] like Fig.14 As shown, when the robot moves from the aforementioned 3 to 1 When the motion mode moves to the motion bifurcation point, the motion axes of the revolute joints D and E coincide, and the robot's motion freedom will suddenly change. At this time, the robot will have two different motion mode tendencies. Fig.15As shown, when the robot moves to the bifurcated configuration, the end protrusion 203 in the mechanical limit at the revolving pair E will fit with the arc-shaped recess 401f. Therefore, in this configuration, when the second drive motor 6 drives the revolving pair D to rotate clockwise, the revolving pair E cannot rotate counterclockwise because the rotation is restricted, so that the movement axes of the revolving pairs D and E remain coincident ( In the motion mode, the two rotation pair axes are separated and always parallel), and the rotation pair E will rotate clockwise along with the rotation pair D, thus entering the remote center motion mode of 3 rotations and 1 shift.

[0079] like Fig.16 As shown, after the revolving pair E rotates clockwise following the revolving pair D, the end protrusion 203 in the mechanical limit 203 at the kinematic pair E is out of contact with the arc-shaped recess 401f again, and there will be no restriction on the movement of the robot. At this time, the fourth robot arm 4 has two rotational degrees of freedom relative to the base box 7. The first rotation axis is the common axis of the revolving pairs A and B, and the second rotation axis is the coincident axis of the revolving pairs D and E. The two rotation axes are perpendicular and orthogonal to a point O. At the same time, the rotation axis of the spline screw shaft 402a in the fourth robot arm 4 will also intersect with the above two axes at point O. Therefore, the motion mode of the actuator connection flange 402i between the end of the robot and the end of the spline screw shaft 402a is a combination of three-dimensional rotational motion around the common intersection O of the three axes and translational motion along the direction of the third rotation axis, which is a three-rotation and one-translation four-degree-of-freedom motion. The working space of the robot in this motion mode is Fig.16 The center of the hollow sphere 11 shown in the figure is the common intersection point O of the three rotation axes. This operation mode of the robot is the same as the motion mode of the center fixed point motion mechanism of the Da Vinci robot, which is also a three-dimensional rotation around a certain point and radial movement along the point, and has application potential in the field of minimally invasive surgical robots.

Claims

1. A remote center movement and The mobile mode metamorphic robot is characterized by: It comprises a first mechanical arm, a second mechanical arm, a third mechanical arm, a fourth mechanical arm and a motion module; a first driving motor is installed at the front end of the first mechanical arm; the inner side surface of the first right-angle connecting piece is arranged toward the first mechanical arm, and one side surface is fixedly connected to the output shaft of the first driving motor to form a rotation pair A; the outer side surface of the second right-angle connecting piece is arranged toward the first mechanical arm, and one side surface is connected to the rear end of the first mechanical arm to form a rotation pair B; the other side surface of the first right-angle connecting piece is connected to one end of the second mechanical arm to form a rotation pair C; the second driving motor is installed on the other side of the second right-angle connecting piece, and the output shaft of the second driving motor is fixedly connected to one end of the third mechanical arm to form a rotation pair D; the other ends of the second mechanical arm and the third mechanical arm are respectively connected to the front end and the end of the fourth mechanical arm to form a rotation pair E and a rotation pair F; so that the fourth mechanical arm has a two-degree-of-freedom one-transfer and one-translation motion relative to the first mechanical arm; the above-mentioned motion pair E is designed with a mechanical limit; A motion module is installed inside the fourth robot arm; the motion module includes a spline screw module and a driving mechanism; wherein the spline screw module includes a spline screw shaft and a spline nut and a screw nut sleeved on it through a spline pair and a screw pair; the spline nut and the screw nut are driven by the driving mechanism to realize individual or joint rotation; the front end of the spline screw shaft passes through the front end surface of the fourth robot arm, and an actuator connecting flange is designed at the end; when the spline nut is driven alone to rotate, the spline screw shaft outputs spiral motion; when the screw nut is driven alone to rotate, the spline screw shaft outputs pure translational motion along the axial direction; when the spline nut and the screw nut are driven synchronously to rotate, the spline screw shaft outputs pure rotational motion, so that the spline screw shaft outputs a two-degree-of-freedom motion of one rotation and one translation, combined with the two-degree-of-freedom one-rotation and one-translation motion of the aforementioned fourth robot arm relative to the first robot arm, a four-degree-of-freedom motion of the actuator connecting flange at the end of the spline screw shaft relative to the first robot arm is obtained; the four-degree-of-freedom motion has two different forms, which respectively generate the robot's Exercise and remote center exercise mode, specifically: When the robot is In the motion mode, the axes of the rotating pair A and the rotating pair B coincide, and the motion axes of the rotating pairs C, D, E and the rotating pair F are parallel to each other. At this time, the mechanical limit at the moving pair E does not contact; the spline screw shaft and its end actuator connecting flange have the freedom of rotation relative to the fourth robot arm and translation along the rotation axis direction, and the rotation axis direction of the spline screw shaft is always parallel to the common axis direction of the rotating pair A and the rotating pair B; therefore, the actuator connecting flange at the end of the spline screw shaft in the fourth robot arm finally outputs a four-degree-of-freedom motion of 3 shifts and 1 rotation relative to the first robot arm, and the rotation direction during the motion is always parallel to the common axis direction of the rotating pair B and the rotating pair C; in this motion mode, the shape of the robot's operating space is a hollow cylinder with the common axis of the rotating pair A and the rotating pair B as the axis; When the robot moves from the aforementioned 3 to 1 When the motion mode moves to the motion bifurcation point, the motion axes of the revolving pairs D and E coincide, and the robot has two different motion mode tendencies. When the robot moves to the bifurcation configuration, the mechanical limit contact at the revolving pair E, and when the second drive motor drives the revolving pair D to rotate clockwise, the rotation of the revolving pair E is restricted, so that the motion axes of the revolving pairs D and E coincide, and the revolving pair E will rotate clockwise with the revolving pair D, thereby entering the remote center motion mode of 3 turns and 1 shift. When the revolving pair E rotates clockwise following the revolving pair D, the mechanical limit at the kinematic pair E is released; at this time, the fourth robot arm has two rotational degrees of freedom relative to the first robot arm, the first rotation axis is the common axis of the revolving pairs A and B, and the second rotation axis is the coincident axis of the revolving pairs D and E, and the two rotation axes are perpendicular and orthogonal to one point O; at the same time, the rotation axis of the spline screw shaft in the fourth robot arm will also intersect with the above two axes at point O; therefore, the motion mode of the actuator connecting flange at the end of the robot and the end of the spline screw shaft is a combination of three-dimensional rotational motion around the common intersection O of the three axes and translational motion along the direction of the third rotation axis, which is a four-degree-of-freedom motion with 3 rotations and 1 translation; in this motion mode, the robot's working space is a hollow sphere, and the center of the sphere is the common intersection O of the three axes.

2. A device with remote center movement and The mobile mode metamorphic robot is characterized by: The first robotic arm is a box structure formed by the butt joint of an upper box and a lower box; the upper box and the lower box are designed with matching shoulders on both sides, which are connected and fixed into one by bolts and through holes evenly distributed on the shoulders.

3. A device as claimed in claim 1 having remote central motion and The mobile mode metamorphic robot is characterized by: The first right-angle connector is designed with openings for connecting the motor and the robot arm on both sides, and the axes of the openings are vertically orthogonal to 90°; the second right-angle connector actually has openings for connecting the robot arm on both sides, and the axes of the openings are vertically orthogonal to 90°.

4. A device with remote center movement and The mobile mode metamorphic robot is characterized by: The box body of the robot arm is assembled from the upper half of the box body and the lower half of the box body; the upper halves of the two boxes and the side edges of the lower halves of the box body are designed with matching shoulders, which are fixed into one by bolts and through holes evenly distributed on the shoulders; two lower connecting plates are designed at the front and rear positions in the lower half of the box body; an upper connecting plate is fixed above the two lower connecting plates by screws; among them, the lower connecting plate located in the front is slotted at the opposite sides of the upper connecting plate, spline nuts are jointly arranged, and are fixed to the upper connecting plate and the lower connecting plate by a flange structure designed circumferentially with the spline nuts; the lower connecting plate located in the rear is slotted at the opposite sides of the upper connecting plate, a lead screw nut is jointly arranged, and is fixed to the upper connecting plate and the lower connecting plate by a flange structure designed circumferentially with the lead screw nut.

5. A device with remote center movement and The mobile mode metamorphic robot is characterized by: The driving mechanism includes two sets of belt transmission mechanisms, which are used to drive the spline nut and the screw nut to rotate respectively; in the two sets of belt transmission mechanisms, the driven pulleys are sleeved on the spline screw shaft and are respectively fixedly connected to the end faces of the spline nut and the screw nut; the two driven pulleys are respectively sleeved with the driving pulleys through transmission belts; the two driving pulleys are coaxially fixed on the output shaft of the driving motor; and the two driving motors are fixed in the fourth mechanical arm.

6. A device with remote center movement and The mobile mode metamorphic robot is characterized by: A protrusion is designed at the end of the second robotic arm, and a recess is designed at the end of the robotic arm box, and the two cooperate to achieve mechanical limiting of the revolute pair E.

Images