An assist mechanism and control method for an autonomous telescopic and rotating collaborative robot

Abstract

This invention provides an assist mechanism for an autonomously telescopic and rotating collaborative robot. The assist mechanism includes a support mechanism vertically mounted on a rotating mechanism and rotating with it. A lateral telescopic mechanism is located at the top of the support mechanism. An assist counterweight mechanism that moves vertically along the support mechanism is also provided on the support mechanism. The connecting and guiding mechanism includes a steel wire rope and a fixed pulley system. One end of the steel wire rope is fixedly connected to the assist counterweight mechanism, and the other end is connected to the end effector of the collaborative robot. A force detection mechanism is used to detect the force applied by the steel wire rope to the assist mechanism along the direction of movement of the telescopic mechanism and the force perpendicular to the direction of movement of the telescopic mechanism. The rotating mechanism, telescopic mechanism, and force detection mechanism are all communicatively connected to a control system. The assist mechanism provided by this invention ensures that the steel wire rope always actively follows the end effector movement of the collaborative robot.

Description

Technical Field

[0001] This invention relates to the field of robot assistance technology, specifically to an assistance mechanism and control method for an autonomous telescopic and rotating collaborative robot. Background Technology

[0002] Collaborative robots refer to a new generation of robots that can safely interact or make direct contact with humans. Currently, the maximum payload of collaborative robots is concentrated below 20kg, mainly due to the following three reasons.

[0003] 1. Structural reasons: In order to achieve high flexibility and precision and reduce collision damage, collaborative robots usually use small torque motors with the advantages of simple control and small size. At the same time, in order to increase the range of spatial movement, flexible joints with hollow wiring structures are used. Due to the low energy density of existing torque motors, existing flexible joints cannot achieve high output power, which limits the load of collaborative robots.

[0004] 2. Reasons for Control: Collaborative robots offer higher safety compared to traditional industrial robots, as they can share workspace with humans. Therefore, collaborative robots employ collision detection algorithms. However, under heavy load conditions, existing collision detection methods, which compare the baseline force calculated using force / torque sensors and dynamic models under normal load with real-time measurements, are prone to misjudging whether it's a load or a collision.

[0005] In the prior art, application number 202111431676.2 discloses a multi-dimensional motion assisting mechanical device for industrial robots. However, its assisting mechanism is a passive rotating mechanical mechanism that cannot extend or retract. The inability of this passive rotating mechanism to actively rotate and extend causes the pulling force generated by the counterweight to be unable to always vertically pull the end load of the collaborative robot, resulting in other directional separation and reduced assisting effect. At the same time, the passive dragging working mode of this mechanism also weakens the assisting effect provided to the collaborative robot. Since the passive mechanical mechanism will passively drag and rotate according to its own dynamic characteristics (damping, mass, and elasticity), when the collaborative robot moves quickly and changes direction, the rotation of the passive mechanism will have a reverse dragging effect on the collaborative robot, which will hinder the movement of the collaborative robot. At the same time, this hindrance will interfere with the accuracy of collision detection of the collaborative robot, affecting work efficiency and safety. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to increase the workload of a collaborative robot without interfering with its operation. To solve the above problem, an assist mechanism and control method for an autonomously telescopic and rotating collaborative robot are provided.

[0007] The object of this invention is achieved in the following manner:

[0008] A power assist mechanism for an autonomous telescopic and rotating collaborative robot includes a rotating mechanism, a supporting mechanism, a power assist counterweight mechanism, a connecting and guiding mechanism, a telescopic mechanism, a force detection mechanism, and a control system. The supporting mechanism is vertically mounted on the rotating mechanism and rotates with it. A transverse telescopic mechanism is provided at the top of the supporting mechanism. The supporting mechanism also has a power assist counterweight mechanism that moves vertically along the supporting mechanism. The connecting and guiding mechanism includes a steel wire rope and a pulley system. The pulley system includes at least two pulleys, which are respectively located at the ends of the telescopic sections of the supporting mechanism and the telescopic mechanism. One end of the steel wire rope is fixedly connected to the power assist counterweight mechanism, and the other end passes through the pulleys on the supporting mechanism and the telescopic mechanism in sequence before connecting to the end of the collaborative robot. The force detection mechanism is used to detect the force applied by the steel wire rope to the power assist mechanism along the direction of movement of the telescopic mechanism and the force perpendicular to the direction of movement of the telescopic mechanism. The rotating mechanism, the telescopic mechanism, and the force detection mechanism are all communicatively connected to the control system.

[0009] The rotating mechanism includes an external gear slewing bearing, a drive gear, a servo motor and its reducer, an upper connecting plate, and a lower connecting plate. The inner ring of the external gear slewing bearing is fixed to the lower connecting plate with screws, and the outer ring fixing hole is fixed to the upper connecting plate with screws. The external gear meshes with the drive gear. The drive gear is fixed to the reducer output shaft with a key and set screws. The output end of the servo motor is connected to the reducer, and the reducer is fixed to the lower connecting plate. The lower connecting plate is fixed to the mounting bracket. When the servo motor rotates, it drives the reducer output shaft to rotate, thereby driving the drive gear to rotate. Through gear transmission, the outer ring of the slewing bearing rotates, thereby driving the upper connecting plate to rotate.

[0010] The support mechanism includes a column, an upper support plate, and a bracket; the lower end of the column is fixed to the upper connecting plate of the rotating mechanism via the bracket, and the upper end of the column is fixed to the bracket and the upper support plate so that it can support the overall structure and rotate with the rotating mechanism.

[0011] The assist counterweight mechanism includes a first guide mechanism, a counterweight block, and a lifting ring. The first guide mechanism is fixed on the support mechanism to make the counterweight block move along a preset trajectory. The counterweight block consists of a counterweight block base plate and a counterweight block housing, which are fixed by bolts. The counterweight block housing has many cavities inside. The lifting ring is bolted to the counterweight block and fixedly connected to one end of a steel wire rope.

[0012] The telescopic mechanism includes a linear motion mechanism, a second guide mechanism, a servo motor and its reducer; the second guide mechanism is fixedly mounted on the support mechanism, the linear motion mechanism is mounted on the guide mechanism and moves according to a preset trajectory, the output end of the servo motor is connected to the reducer, and the output end of the reducer is connected to the linear motion mechanism to drive the linear motion mechanism to move.

[0013] The force detection mechanism includes two pressure sensors; the force measuring planes of both pressure sensors are perpendicular to the bottom surface, the force measuring plane of the first pressure sensor is perpendicular to the direction of movement of the telescopic mechanism, and the force measuring plane of the second pressure sensor is parallel to the direction of movement of the telescopic mechanism.

[0014] The control system includes a motion control module, sensor signal analysis equipment, and servo control.

[0015] A control method for the assist mechanism of an autonomous telescopic and rotating collaborative robot includes the following steps: controlling the rotation and telescopic positions according to a set operating mode, which includes a collaborative target tracking mode and an impedance control mode during bus transmission. In the collaborative target tracking mode, the robot obtains the real-time end-effector target tracking trajectory through bus communication. Based on this information, the assist mechanism calculates the rotation and telescopic trajectory using its own kinematics and completes the collaborative motion through servo drive control. In the impedance mode, a pressure sensor monitors the torque and pressure generated by the wire rope on the end of the telescopic mechanism in real time. The target control mechanism rotates and telescopically controls the target trajectory of the rotation and telescopic movement by generating the rotation and telescopic trajectory through a set impedance.

[0016] The impedance control mode works by detecting the pressure changes generated by the deflection of the steel cable during the collaborative robot's movement, which affect the two-stage pressure sensors of the assist mechanism. This yields the pressure at the telescopic end and calculates the torque on the rotating mechanism. Based on this real-time pressure and torque information, impedance control is used to control the rotation and telescopic movement of the assist mechanism. The goal is to minimize passive lateral drag on the assist mechanism due to the collaborative robot's movement, reduce the tension or pressure of the steel cable on the telescopic mechanism, and ensure that the counterweight always provides vertical assistance. The impedance control uses the pressure F on the telescopic mechanism along its movement direction obtained from the first pressure sensor and the torque T on the rotating mechanism obtained and calculated from the second pressure sensor as input to the impedance controller to obtain the target tracking position. The impedance control for extension and rotation are respectively

[0017] , ,

[0018] in These represent the natural frequencies and damping ratios of the stretching and rotating axes in the impedance model, respectively. and These are the inertia, damping, and elastic parameters in the extension and rotation impedance models, respectively. By adjusting the natural frequency and damping ratio, or the inertia, damping, and elastic parameters, the transient and steady-state responses of the assist mechanism can be adjusted.

[0019] The method also includes a safety mode. When the assist mechanism is controlled in a collaborative target tracking mode with bus transmission, if the target movement of the collaborative robot is detected to be outside the workspace of the assist mechanism, the control system will issue an alarm and stop the movement of the collaborative robot and the assist mechanism. When the assist mechanism is controlled in an impedance control mode, if the actual pressure of the two pressure sensors is detected to be greater than the set safety threshold, signals will be sent to the collaborative robot and the assist mechanism respectively, causing them to stop suddenly or return to zero, thus protecting the equipment.

[0020] The beneficial effects of this invention are as follows: The assist mechanism provided by this invention, with its rotation and telescopic mechanisms, ensures that the wire rope always actively follows the end effector movement of the collaborative robot. The wire rope, in conjunction with the adjustable counterweight, provides efficient and reasonable assistance. Its autonomous rotation and telescopic movement ensure that the direction of the force transmitted through the wire rope is always vertically above the end effector of the collaborative robot, consistently providing load assistance and maximizing load lifting while avoiding additional resistance to the collaborative robot. The bus control mode and impedance control mode ensure compatibility with collaborative robots with varying degrees of control interface openness, and the safety mode guarantees the coordinated safety of the assist mechanism and the collaborative robot. Attached Figure Description

[0021] Figure 1 This is a three-dimensional schematic diagram of the overall structure of the present invention (including the collaborative robot).

[0022] Figure 2 This is a schematic diagram of the rotating mechanism in this invention.

[0023] Figure 3 This is a schematic diagram of the support mechanism in this invention.

[0024] Figure 4 This is a schematic diagram of the assist counterweight mechanism in this invention.

[0025] Figure 5 yes Figure 1 A magnified view of part A in the middle.

[0026] Figure 6 This is a partial diagram of the connection and guiding mechanism in this invention.

[0027] Figure 7 yes Figure 3 The view on the right.

[0028] Figure 8 yes Figure 1 Enlarged view of the end of section B.

[0029] Figure 9 This is a flowchart of the control method of the present invention.

[0030] Figure 10 This is the control principle diagram of the present invention.

[0031] Among them, 01-first pressure sensor, 02-second pressure sensor, 1-rotation mechanism, 2-support mechanism, 3-assist counterweight mechanism, 4-telescopic mechanism, 5-collaborative robot, 6-wire rope, 7-first fixed pulley, 8-third fixed pulley, 9-second fixed pulley, 10-fourth fixed pulley, 11-external toothed slewing support bearing, 12-drive gear, 13-upper connecting plate, 14-lower connecting plate, 21-column, 22-upper support plate, 23-bracket, 31-counterweight block, 32-lifting ring, 311-counterweight block base plate, 312-counterweight block housing, 313-cavity, 41-linear motion mechanism, 42-second guide mechanism. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0033] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same technical meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0034] like Figure 1 As shown, this invention provides an assist mechanism for an autonomously telescopic and rotating collaborative robot. The assist mechanism includes a rotating mechanism 1, a supporting mechanism 2, an assist counterweight mechanism 3, a connecting and guiding mechanism, a telescopic mechanism 4, a force detection mechanism, and a control system. The supporting mechanism 2 is vertically mounted on the rotating mechanism 1 and rotates with it. A transverse telescopic mechanism 4 is located at the top of the supporting mechanism 2. The supporting mechanism 2 also has an assist counterweight mechanism 3 that moves vertically along the supporting mechanism. The connecting and guiding mechanism includes a steel wire rope 6 and a set of fixed pulleys. The fixed pulley set includes at least two fixed pulleys, which are respectively located at the ends of the telescopic sections of the supporting mechanism and the telescopic mechanism. One end of the steel wire rope 6 is fixedly connected to the assist counterweight mechanism, and the other end passes through the fixed pulleys on the supporting mechanism 2 and the telescopic mechanism 4 in sequence before connecting to the end of the collaborative robot 5. The force detection mechanism detects the force applied by the steel wire rope to the assist mechanism along the direction of movement of the telescopic mechanism and the force perpendicular to the direction of movement of the telescopic mechanism. The rotating mechanism, the telescopic mechanism, and the force detection mechanism are all communicatively connected to the control system.

[0035] In this embodiment, the fixed pulley group includes four fixed pulleys: a first fixed pulley 7 disposed on the bottom surface of the top of the support mechanism 2, a second fixed pulley 9 disposed on the auxiliary counterweight mechanism, a third fixed pulley 8 disposed on the top upper surface of the support mechanism, and a fourth fixed pulley 10 disposed at the end of the telescopic end of the telescopic mechanism; the support mechanism is provided with holes 24 for the steel wire rope 6 to pass through from the bottom surface of the top of the support mechanism to the top upper surface of the support mechanism, such as... Figure 7 As shown; one end of the wire rope 6 is fixedly connected to the assist counterweight mechanism 3 and then passes through the first fixed pulley 7, the second fixed pulley 9, the third fixed pulley 8 and the fourth fixed pulley 10 in sequence before being connected to the end of the collaborative robot 5; the force detection mechanism is used to detect the force applied by the wire rope to the assist mechanism along the direction of movement of the telescopic mechanism and the force perpendicular to the direction of movement of the telescopic mechanism; the force detection mechanism is set at the telescopic end of the telescopic mechanism 4; the rotating mechanism, the telescopic mechanism and the force detection mechanism are respectively connected to the control system for communication.

[0036] like Figure 2 As shown, the rotating mechanism 1 includes an external gear slewing bearing 11, a drive gear 12, a servo motor and its reducer, an upper connecting plate 13, and a lower connecting plate 14. The inner ring of the external gear slewing bearing 11 is fixed to the lower connecting plate 14 with screws, and the outer ring fixing hole is fixed to the upper connecting plate 13 with screws. The external teeth mesh with the drive gear 12. The drive gear 12 is fixed to the reducer output shaft with a key and set screws. The output end of the servo motor is connected to the reducer, which is fixed to the lower connecting plate 14. The lower connecting plate 14 is fixed to the mounting bracket. When the servo motor rotates, it drives the reducer output shaft to rotate, thereby driving the drive gear 12 to rotate. Through gear transmission, the outer ring of the slewing bearing 11 rotates, thereby driving the upper connecting plate 13 to rotate. The control end of the servo motor is communicatively connected to the control system.

[0037] like Figures 1-3 As shown, the support mechanism 2 includes a column 21, an upper support plate 22, and a bracket 23; the lower end of the column 21 is fixed to the upper connecting plate 13 of the rotating mechanism through the bracket 23, and the upper end of the column 21 is fixed to the upper support plate 22 through the bracket 23 so that it can support the overall structure and rotate with the rotating mechanism.

[0038] like Figure 4 As shown, the assist counterweight mechanism 3 includes a first guide mechanism, a counterweight block 31, and a lifting ring 32; the first guide mechanism is fixed on the support mechanism 2 to make the counterweight block 31 move along a preset trajectory. The counterweight block 31 is composed of a counterweight block base plate 311 and a counterweight block box 312, which are fixed by bolts. The counterweight block box 312 has a number of cavities 313 inside; the lifting ring 32 is bolted to the counterweight block 31 and fixedly connected to one end of the wire rope 6.

[0039] like Figure 8 As shown, the force detection mechanism includes two pressure sensors; the force-measuring planes of both pressure sensors are perpendicular to the bottom surface. The force-measuring plane of the first pressure sensor 01 is perpendicular to the direction of movement of the telescopic mechanism, and the force-measuring plane of the second pressure sensor 02 is parallel to the direction of movement of the telescopic mechanism. It is used to detect the force applied by the wire rope to the mechanism along the direction of movement of the telescopic mechanism and the force perpendicular to the direction of movement of the telescopic mechanism.

[0040] like Figures 5-7 As shown, the telescopic mechanism 4 includes a linear motion mechanism 41, a second guide mechanism 42, a servo motor, and a reducer. The second guide mechanism is fixedly mounted on the support mechanism 2. The linear motion mechanism is mounted on the guide mechanism and moves according to a preset trajectory. The output end of the servo motor is connected to a reducer, and the output end of the reducer is connected to the linear motion mechanism to drive its movement. The linear motion mechanism includes, but is not limited to, a rack and pinion mechanism, a lead screw mechanism, a screw mechanism, and a crank-slider mechanism. The second guide mechanism includes, but is not limited to, a linear guide rail, a smooth rod guide rail, and a mechanism combining the linear motion mechanism and the second guide mechanism, such as an electric push rod. The telescopic mechanism is fixed to a support plate on the support mechanism and rotates with the whole structure. The parts that move in the telescopic mechanism are fixed to the force detection mechanism and move together with the guide mechanism at the end of the wire rope as the telescopic mechanism moves. In the embodiment of this application, the linear motion mechanism uses a rack and pinion mechanism. The control end of the servo motor is communicatively connected to the control system.

[0041] The control system includes a motion control module, a sensor signal analysis device, and a servo control system. The motion control module includes, but is not limited to, a PLC, a motion controller, and a motion control development board. The servo control system includes a servo driver; the input of the servo driver is communicatively connected to the control module, and the output of the servo driver is communicatively connected to the servo motor control terminals of the telescopic mechanism and the rotary mechanism, respectively. The input of the sensor signal analysis device is connected to two pressure sensors of the force detection mechanism, and the output is connected to the motion control module. The sensor signal analysis device includes a signal amplifier, an A / D converter, and a communication module.

[0042] like Figure 9 As shown, a control method for the assist mechanism of an autonomous telescopic and rotating collaborative robot includes the following steps: controlling the rotation and telescopic positions according to a set working mode, which includes a collaborative target tracking mode and an impedance control mode during bus transmission. In the collaborative target tracking mode, the robot obtains the real-time end target tracking trajectory through bus communication, and the assist mechanism calculates the rotation and telescopic trajectory based on this information and its own kinematics, and completes the collaborative motion through servo drive control. In the impedance mode, the torque and pressure generated by the wire rope on the end of the telescopic mechanism are monitored in real time by a pressure sensor, and the rotation and telescopic trajectory target is generated by the set impedance to control the rotation and telescopic movement of the mechanism.

[0043] The collaborative target tracking mode is as follows: the target motion trajectory of the collaborative robot in the workspace is obtained through the bus, the target motion trajectory of the assist mechanism coordinate system is obtained through coordinate transformation, and the trajectory of the servo motor of the telescopic mechanism and the servo motor of the rotary mechanism are obtained after numerical interpolation based on the inverse kinematics solution of the assist mechanism. The collaborative motion of the assist mechanism and the collaborative robot is completed through servo control.

[0044] like Figure 10 As shown, the impedance control mode works by detecting the pressure changes generated by the deflection of the steel cable on the assist mechanism's two-stage pressure sensors during the collaborative robot's movement. This yields the pressure at the telescopic end and calculates the torque on the rotating mechanism. Based on this real-time pressure and torque information, impedance control is used to control the rotation and telescopic movement of the assist mechanism. The goal is to minimize passive lateral drag on the assist mechanism due to the collaborative robot's movement, reduce the tension or pressure of the steel cable on the telescopic mechanism, and ensure that the counterweight always provides vertical assistance. The impedance control obtains the pressure F on the telescopic mechanism along its movement direction from the first pressure sensor and the torque T on the rotating mechanism from the second pressure sensor, using these as inputs to the impedance controller to obtain the target tracking position. The impedance control for extension and rotation are respectively

[0045] , ,

[0046] in These represent the natural frequencies and damping ratios of the stretching and rotating axes in the impedance model, respectively. and These are the inertia, damping, and elastic parameters in the extension and rotation impedance models, respectively. By adjusting the natural frequency and damping ratio, or the inertia, damping, and elastic parameters, the transient and steady-state responses of the assist mechanism can be adjusted.

[0047] The method also includes a safety mode. When the assist mechanism is controlled in a collaborative target tracking mode with bus transmission, if the target movement of the collaborative robot is detected to be outside the workspace of the assist mechanism, the control system will issue an alarm and stop the movement of the collaborative robot and the assist mechanism. When the assist mechanism is controlled in an impedance control mode, if the actual pressure of the two pressure sensors is detected to be greater than the set safety threshold, signals will be sent to the collaborative robot and the assist mechanism respectively, causing them to stop suddenly or return to zero, thus protecting the equipment.

[0048] The assist mechanism provided by this invention features a rotation and extension mechanism that ensures the steel wire rope always actively follows the end effector movement of the collaborative robot. The steel wire rope, in conjunction with an adjustable counterweight, provides efficient and reasonable assistance. Its autonomous rotation and extension ensure that the direction of assistance transmitted through the steel wire rope is always vertically above the end effector of the collaborative robot, consistently providing load assistance and maximizing load lift while avoiding additional resistance. Bus control and impedance control modes ensure compatibility with collaborative robots with varying degrees of control interface openness, while a safety mode guarantees the collaborative safety of both the assist mechanism and the collaborative robot.

[0049] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several changes and improvements without departing from the overall concept of the present invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. A power-assisted mechanism for an autonomous, self- extending, self-rotating, collaborative robot, characterized by: The assisting mechanism comprises a rotating mechanism (1), a supporting mechanism (2), an assisting counterweight mechanism (3), a connecting and guiding mechanism, an extension mechanism (4), a force detecting mechanism and a control system, the supporting mechanism (2) is vertically arranged on the rotating mechanism (1) and rotates with the rotating mechanism, the top of the supporting mechanism (2) is provided with the transverse extension mechanism (4), the assisting counterweight mechanism (3) is further arranged on the supporting mechanism (2) and moves along the up-down direction of the supporting mechanism, the connecting and guiding mechanism comprises a steel wire rope (6) and a fixed pulley set, the fixed pulley set comprises at least two fixed pulleys, the two fixed pulleys are arranged at the ends of the extension section of the extension mechanism (4) and the supporting mechanism (2) respectively, one end of the steel wire rope (6) is fixedly connected to the assisting counterweight mechanism (3), the other end of the steel wire rope (6) is sequentially threaded through the fixed pulleys on the supporting mechanism (2) and the extension mechanism (4) and then connected to the tail end of the collaborative robot (5), the force detecting mechanism is used for detecting the force applied by the steel wire rope on the assisting mechanism along the movement direction of the extension mechanism (4) and the force perpendicular to the movement direction of the extension mechanism (4), the rotating mechanism (1), the extension mechanism (4) and the force detecting mechanism are respectively in communication connection with the control system, the assisting counterweight mechanism (3) comprises a first guiding mechanism, a counterweight block (31) and a lifting ring (32), the first guiding mechanism is integrally fixed on the supporting mechanism (2) to make the counterweight block (31) move along a preset track, the counterweight block (31) is composed of a counterweight block bottom plate (311) and a counterweight block box (312) and is fixed by bolts, the counterweight block box (312) has a plurality of cavities (313) in the inside, the lifting ring (32) is connected to the counterweight block (31) by bolts and is fixedly connected to one end of the steel wire rope (6); The force detecting mechanism comprises two pressure sensors, the force measuring planes of the two pressure sensors are both perpendicular to the bottom surface, the force measuring plane of the first pressure sensor (01) is perpendicular to the movement direction of the extension mechanism, the force measuring plane of the second pressure sensor (02) is parallel to the movement direction of the extension mechanism; The pressure at the telescopic end is obtained by detecting the change of the pressure generated by the two-stage pressure sensor of the assisting mechanism when the steel wire is deflected during the movement of the collaborative robot, and the torque received by the rotating mechanism is calculated. According to the real-time information of the pressure and torque, the telescopic control of the rotation and telescopic of the assisting mechanism is completed through impedance control, the goal is to make the assisting mechanism as passive as possible to avoid being dragged horizontally by the movement of the collaborative robot, reduce the tension or pressure of the steel wire on the telescopic mechanism (4), and ensure that the counterweight always plays a role in assisting the vertical direction; the impedance control obtains the pressure F on the telescopic mechanism in the movement direction of the telescopic mechanism through the first pressure sensor and obtains the torque T on the rotating mechanism through the second pressure sensor and calculation, which is input to the impedance controller to obtain the target tracking position and , the impedance control of telescopic and rotation is ， ， wherein ω0and ζ are the natural frequency and damping ratio of the extensional and rotational axis in the impedance model, respectively, and ω0and ζ are the natural frequency and damping ratio of the extensional and rotational axis in the impedance model, respectively, and ω0and ζ are the natural frequency and damping ratio of the extensional and rotational axis in the impedance model, respectively, and 2. The assist mechanism of the self-extendable and self-rotatable collaborative robot according to claim 1, wherein: The rotating mechanism (1) comprises an external-tooth type rotary support bearing (11), a driving gear (12), a servo motor and a reducer and an upper connecting plate (13) and a lower connecting plate (14), the inner ring of the external-tooth type rotary support bearing (11) is fixed to the lower connecting plate (14) by screws, the outer ring fixing hole is fixed to the upper connecting plate (13) by screws, and the external teeth are engaged with the driving gear (12), the driving gear (12) is fixed to the output shaft of the reducer by keys and locking screws, the output end of the servo motor is transmissionally connected with the reducer, and the reducer is fixed to the lower connecting plate (14), the lower connecting plate (14) is fixed to the mounting bracket, when the servo motor rotates, the output shaft of the reducer is driven to rotate, thereby driving the driving gear (12) to rotate, the rotary support bearing (11) outer ring is driven to rotate through gear transmission, thereby driving the upper connecting plate (13) to rotate.

3. The assist mechanism of the self-extendable and self-rotatable collaborative robot according to claim 2, wherein: The support mechanism (2) comprises a column (21), an upper support plate (22) and a bracket (23); the lower end of the column (21) is fixed with the rotating mechanism upper connecting plate (13) through the bracket (23), and the upper end of the column (21) is fixed with the bracket (23) and the upper support plate (22) so as to support the whole structure and rotate with the rotating mechanism.

4. The assist mechanism of the self-extendable and self-rotatable collaborative robot according to claim 1, wherein: The telescopic mechanism (4) comprises a linear motion mechanism (41), a second guide mechanism (42), a servo motor and a reducer thereof; the second guide mechanism is fixedly arranged on the support mechanism (2), the linear motion mechanism is arranged on the guide mechanism and moves according to a preset track, the output end of the servo motor is transmissionally connected with the reducer, and the output end of the reducer is connected with the linear motion mechanism and used for driving the linear motion mechanism to move.

5. The assist mechanism of the self-extendable and self-rotatable collaborative robot according to claim 1, wherein: The control system comprises a motion control module, a sensor signal analysis device and a servo control.

6. The control method of the power-assisted mechanism of the self- extending and rotating collaborative robot according to any one of claims 1-5, characterized in that: The control method comprises the following steps: controlling the positions of rotation and telescoping according to a set working mode, the working mode comprising a cooperative target tracking mode and an impedance control mode during bus transmission, the cooperative target tracking mode obtaining a real-time end target tracking trajectory of a collaborative robot through bus communication, the rotation and telescoping trajectory being obtained by the power assisting mechanism in combination with kinematic calculation according to the real-time end target tracking trajectory of the collaborative robot, and the cooperative motion being completed through servo drive control; the impedance mode monitoring the torque and pressure generated by the steel wire rope on the end of the telescopic mechanism through a pressure sensor in real time, and the rotation and telescoping trajectory target controlling the rotation and telescoping of the mechanism through the set impedance.

7. The control method according to claim 6, characterized in that: The method further comprises a safety mode, when the control working mode of the power assisting mechanism is the cooperative target tracking mode during bus transmission, if it is detected that the target moving position of the collaborative robot is outside the working space of the power assisting mechanism, the control system will issue an alarm and stop the motion of the collaborative robot and the power assisting mechanism; when the control mode of the power assisting mechanism is the impedance control mode, if it is monitored that the actual pressure of the two-stage pressure sensor is greater than the set safety threshold, signals are sent to the collaborative robot and the power assisting mechanism respectively, so that both of them are stopped urgently or returned to zero, and the equipment is protected.

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