CN114872938A - Self-growing flexible variable stiffness mechanical arm space cross-size target automatic capture control method - Google Patents

Abstract

A self-growth flexible variable-stiffness mechanical arm space cross-size target automatic capture control method comprises the following steps: a teleoperation mode and an automatic acquisition mode, wherein: teleoperation mode refers to: adjusting in real time according to the position of the target object through the preset length of each section of the mechanical arm main body and the preset bending angle of each joint so as to enable the tail end of the mechanical arm to reach the position of the target object; the automatic capture mode is: firstly, determining to use a grabbing strategy or a winding strategy according to the size of the target object, adopting the grabbing strategy when the volume of the target object is within the grabbing range of the gripper at the tail end of the mechanical arm, and adopting the winding strategy otherwise; the length of the mechanical arm in the grabbing or winding strategy is distributed according to the principle that the maximum torque is equal. The flexible variable-stiffness mechanical arm has two strategies of grabbing and winding aiming at target objects with different sizes, does not need additional dismounting and mounting of additional parts when being switched between the two strategies, has higher flexibility, larger working range and stronger adaptability, and has the characteristics of capability of being accommodated, light weight, large action range and the like when being adaptive to space self-growth flexible variable-stiffness mechanical arm.

Description

Automatic capture control method for self-growing flexible variable stiffness manipulators in space spanning size targets

technical field

The invention relates to a technology in the field of space technology equipment, in particular to a self-growing flexible variable-stiffness manipulator arm space automatic capture control method for cross-dimension targets.

Background technique

Space technology is the crystallization of the development of human science and technology, and is the basis for human exploration of the vast universe. Orbital garbage capture technology is proposed in the context of more and more frequent human space activities. The goal is to ensure the safe operation of space personnel and equipment. Space pest removal or transfer technology. Existing track waste capture technologies mainly use rigid robotic arms or cable-net capture devices. However, due to its limited length, the rigid manipulator has a short working distance, which makes it difficult to capture long-distance rail debris; its joint position is relatively fixed, making it difficult to achieve a flexible control strategy; the rigid manipulator is generally equipped with a gripper at the end to capture the target, but When the target is large, the gripper is often not enough to grasp the target, so it lacks a capture strategy for large targets. While the cable-net capture device can capture long-distance and various-scale orbital garbage, it is often disposable and cannot be reused.

SUMMARY OF THE INVENTION

Aiming at the defect that the existing technology can only realize the expansion and contraction of the space manipulator, but cannot control its bending, the present invention proposes a self-growing flexible and variable stiffness manipulator space automatic capture control method for the space cross-dimensional target. Capture mode, there are two strategies of grabbing and wrapping for target objects of different sizes, and the conversion between the two strategies does not require additional disassembly and assembly of additional components, with higher flexibility, larger working range and stronger adaptation At the same time, it adapts to the characteristics of space self-growing flexible variable stiffness manipulator, which can be stowed, light in weight, and large in scope.

The present invention is achieved through the following technical solutions:

The invention relates to a self-growing flexible variable stiffness manipulator arm space automatic capture control method, including: a remote operation mode and an automatic capture mode, wherein: the remote operation mode refers to: through the preset length of each manipulator main body and the bending angle of each joint, and adjust in real time according to the position of the target, so that the end of the robot arm reaches the position of the target; automatic capture mode means: first decide to use the grasping strategy or winding strategy according to the size of the target, when When the volume of the target is within the grasping range of the gripper at the end of the robotic arm, the grasping strategy is adopted, otherwise, the winding strategy is adopted; the distribution of the length of the robotic arm in the grasping or winding strategy adopts the principle of equal maximum torque.

The self-growing flexible and variable-stiffness robotic arm includes: a central controller, a base, a gripper, a robotic arm body whose ends are respectively connected to the base and the gripper, and several joints movably arranged on the robotic arm body, wherein : The joint moves on the main body of the robot arm by moving the motor, thereby changing the local stiffness of the main body of the robot arm, and bending the main body of the robot arm there through the bending motor, and the central controller sends information to the base or the joint through the instructions input by the user To achieve coordinated control between motors.

The base and each joint are provided with a local controller, and the local controller includes: a power supply unit, a communication unit, a processing unit, a motor unit, and a sensing unit, wherein: the power supply unit passes through the step-up element and the step-down element. Provide energy to the communication unit, processing unit, motor unit and sensing unit respectively; the communication unit receives the information transmitted by the central controller and transmits it to the processing unit, and the processing unit converts the information into a level signal and transmits it to the motor unit, the motor unit The corresponding rotation is performed according to the received level signal. At the same time, the sensing unit obtains the corresponding rotation angle information according to the actual operation of the motor unit, and transmits it back to the processing unit. The processing unit performs closed-loop control calculation according to the obtained rotation angle signal. , and transmit the adjusted level signal to the motor unit.

The grasping strategy includes: inputting the position of the target, calculating the length of the manipulator and the angle of the joint by the central controller, sending instructions to the base and the joint from the central controller, and completing the corresponding action by the base and the joint and accurately using the position and angle sensors. Control the movement, the end gripper of the robotic arm reaches the target site, implement the grasping action, transfer or recover the robotic arm, and release the target by the end gripper.

The central controller adopts the equiangular principle when calculating the rotation angle of each joint according to the instructions input by the user, so as to ensure that the bending motor losses of each joint are similar, and at the same time, it is beneficial to the equal moment of the manipulator segment; the central controller When calculating the length of the manipulator segment, the principle of equal moment is adopted, that is, try to keep the maximum moment on each manipulator segment equal to avoid local premature buckling, so as to improve the bearing capacity of the whole manipulator.

The winding strategy includes: dividing the entire robotic arm into a main arm part for reaching the position of the target and a fine arm part for winding the target, respectively, including: inputting the position and size of the target, a central controller Calculate the length and joint angle of the main arm, the central controller sends instructions to the base and joints, the base and joints complete corresponding actions and perform closed-loop control through position and angle sensors, the end of the main arm and the fine arm reach the target position, the fine arm The winding action is implemented according to the shape of the target and closed-loop control is carried out through position and angle sensors, the main arm is transported or recovered, and the fine arm is recovered to release the target.

technical effect

The invention utilizes the principle of equal moment to plan the length of the arm segment of the self-growing flexible variable stiffness manipulator, and makes the end of the manipulator reach the designated position through the coordinated control of the base and the joint motor. Based on the principle of equal moment and the coordinated control of the motor, the manipulator can be manually controlled in real time in the remote operation mode, or the manipulator can be autonomously planned in the automatic capture mode. The target adopts the winding strategy. This method enables the self-growing flexible variable stiffness manipulator to avoid premature buckling and maximize its bearing capacity. The control method adopts different capture methods for different distances and sizes of space orbital garbage, and solves the problem of insufficient adaptability to different types of targets in the current space orbital garbage capture.

Description of drawings

Figure 1 is a schematic diagram of a space self-growing flexible variable stiffness manipulator;

FIG. 2 is a flowchart of a control method for a space self-growing flexible variable stiffness manipulator;

FIG. 3 is a schematic diagram of the cooperative control between motors applied to the control method of the space self-growing flexible variable stiffness manipulator;

4 is a schematic diagram of a local controller;

Fig. 5 is the schematic diagram of the manipulator in the calculation of the equal moment principle;

Figure 6 is an effect diagram of the implementation of the principle of equal moments;

Fig. 7 is a graph showing the influence of the end arm segment on the equi-moment effect;

8 is a schematic diagram of the grasping strategy of the three-joint robotic arm in Embodiment 2;

9 is a schematic diagram of the capture simulation process shown by the time node of the three-joint robotic arm in Embodiment 2;

10 is a schematic diagram of the winding strategy of the double-joint main arm and the four-joint fine arm in Example 3;

11 is a schematic diagram of the capture simulation process displayed by time nodes of the double-joint main arm and the four-joint fine arm in Embodiment 3;

In the picture: 1 base, 2 manipulator main body, 3 joints, 101 power supply unit, 102 processing unit, 103 communication unit, 104 motor unit, 105 sensing unit, 4 gripper, I main arm, II fine arm.

Detailed ways

Example 1

As shown in FIG. 1 , this embodiment relates to a space self-growing flexible and variable-stiffness manipulator, including: a base 1 , a gripper 4 , a manipulator body 2 whose two ends are respectively connected to the base 1 and the gripper 4 , and Several joints 3 are movably arranged on the main body of the robot arm 2, wherein: the joints 3 move on the main body of the robot arm 2 by moving the motor, thereby changing the local stiffness of the main body of the robot arm 2, and by bending the motor, the main body of the robot arm 2 is moved on the robot arm body 2. bending occurs.

The changing of the local stiffness of the manipulator body 2 means that the manipulator body 2 has a certain stiffness in the unfolded state. Bending is more likely to occur there.

The manipulator body 2 is stored in the base 1 by winding, and when the motor on the base 1 rotates, it can drive the manipulator body 2 to extend or retract. Larger, the accommodated part is in a buckling state, and the stiffness is small.

As shown in FIG. 2, the present embodiment based on the above-mentioned self-growing flexible variable-stiffness manipulator arm based on the automatic capture control method for spatial cross-dimension targets, including: a remote operation mode and an automatic capture mode, wherein: the remote operation mode refers to: by preset The length of each segment of the manipulator body 2 and the bending angle of each joint 3 are adjusted in real time according to the position of the target object, so that the end of the manipulator arm reaches the target object position; automatic capture mode means: first, according to the size of the target object It is decided to use the grabbing strategy or the wrapping strategy. If the target is small, the grabbing strategy is adopted. If the size of the target exceeds the grasping range of the gripper 4, the wrapping strategy is adopted.

As shown in Figure 2, Figure 8 and Figure 9, the grasping strategy refers to: first, the central controller calculates the length of each robotic arm according to the principle of equal moments; then sends a signal to the base and each joint to make The base motor and the movement motor on the joint work together to make the length of each robotic arm segment reach the specified value; then drive the bending motor at the joint to make the joint angle reach the specified value, so that the gripper 4 at the end of the robotic arm reaches the target After grabbing the target, the gripper 4 re-sets the target position to the central controller; the robotic arm transfers or recovers to the target position, and the gripper releases the captured object to complete a job.

As shown in Fig. 2, Fig. 10 and Fig. 11, the winding strategy refers to: firstly, the growth and bending of the main body arm I is carried out. This process is similar to the grasping strategy. First, the central controller calculates the main body arm according to the principle of equal moments ⅠThe length of each manipulator arm; and then send a signal to the joint of the base and the main arm I, so that the base motor and the moving motor on the main arm I cooperate with each other, so that the length of each manipulator segment of the main arm I reaches the specified length. Then drive the bending motor at the joint of the main arm I to make the rotation angle of the joint reach the specified value, so that the end of the main arm I and the fine arm II reach the position of the target; the fine arm II grows and wraps according to the shape of the target. At this time, the movement motors of the main arm I and the fine arm II are required to work together; after the fine arm II completes the winding action on the target, the target position is re-set to the central controller; the main arm I is transported or recovered to the target position, and the fine arm II The winding action remains unchanged; the fine arm II starts to recover from the end, releases the captured objects, and the robotic arm completes one job as a whole.

As shown in Figure 3, after specifying the length of a certain manipulator segment, it needs to be controlled by the motor of the base 1 and the movement motor of each joint 3 to make each manipulator segment reach the specified length. As shown in Figure 3, when the arm i needs to be extended, and the length of the other arms does not change, the central controller sends commands to the base 1 and the joints 3 from 1 to i-1, and the motor of the base 1 sends instructions. Rotate in the forward direction, unfold the wound manipulator body 2 and send it out of the base 1, while the moving motors of the joints 3 of Nos. 1 to i-1 rotate in the reverse direction at the same speed as the motor of the base 1. The movement motor of joint 3 does not rotate, so that only arm i is extended. Similarly, when the i-arm needs to be shortened, the motor of the base 1 rotates in the opposite direction, winding the unfolded manipulator body 2 back to the base 1, and the moving motors of the joints 1 to i-1 are driven by the base 1. The motor of 1 rotates in the forward direction at the same speed, and the movement motor of joint 3 of number i to n does not rotate, so that only the arm of number i is shortened.

As shown in FIG. 4 , the power supply unit 101 in the local controller provides energy 105 to the communication unit 103 , the processing unit 102 , the motor unit 104 and the sensing unit respectively through the boosting element and the depressing element; the communication unit 103 receives the central The information transmitted by the controller is passed to the processing unit 102, and the processing unit 102 converts the information into a level signal and transmits it to the motor unit 104. The motor unit 104 performs corresponding rotation according to the received level signal, while the sensing unit 105 According to the actual operation of the motor unit 104, the corresponding rotation angle information is obtained and transmitted back to the processing unit 102. The processing unit 102 performs closed-loop control calculation according to the obtained rotation angle signal, and transmits the adjusted level signal to the motor unit 104. .

As shown in FIG. 5 to FIG. 7 , the teleoperation mode of this embodiment adopts the principle of equal moment, that is, the maximum moment received by each manipulator segment is kept equal. In the process of calculating the equi-moment principle, first make abstractions and assumptions about the manipulator: ①The mass of the main body 1 of the manipulator is smaller than that of the joint 3, and the mass of the joint 3 is much smaller than the mass of the target object; ②The mass of the main body 1 of the manipulator is smaller than that of the joint 3 Joint 3 is regarded as a mass point; ③ The first segment of the robotic arm is connected to the base 1 and does not bend.

每一个机械臂段末端受到的力为其后机械臂所受力之和，即

其中：最末端的机械臂段所对应的质量为目标物的质量M，其余机械臂对应的质量均为关节3的质量m。As shown in Figure 5, in order to use a double-joint space self-growing flexible variable stiffness manipulator, the motor-to-motor synergistic control method, the base 1, joint 3, and gripper 4 are simplified as circles in the figure, and the manipulator body 2 Simplified to straight lines. The dual-joint space self-growing flexible and variable-stiffness manipulator includes two bending positions and three manipulator segments. During the expansion and contraction of the manipulator body 2, the manipulator segment is not subjected to force in the vertical direction, and no buckling action occurs. Therefore, only Consider the vertical force at the end of each arm segment during the bending process, including: the acceleration at the end of the i-th arm segment

The force on the end of each manipulator segment is the sum of the forces on the following manipulators, namely

Among them: the mass corresponding to the endmost manipulator segment is the mass M of the target object, and the masses corresponding to the rest of the manipulators are the mass m of the joint 3.

由于目标物的质量M远大于关节3的质量m，因此简化为

其中：

为机械臂最末端抓手4的横向加速度和纵向加速度，可以由抓手4的横坐标和纵坐标对时间求二阶导获得，注意在求导过程中仅有角度随时间发生变化，各机械臂段的长度不随时间发生变化，并且θ₁及其导数均为0,其余的转动视为匀速转动。将

代入到力矩等式中，并令l₃＝k₃l₁＝k₃l，l₂＝k₂l₁＝k₂l，θ₃＝Kθ₂＝Kθ，l为基准长度，θ为基准角，则有

考虑到转动电机的损耗问题，各个关节3的转动采用等角原则，即K＝1；而θ为已知条件，那么由上式可以得到k₂与k₃的关系。若机械臂段之间的长度比例满足该关系，则1号臂和2号臂所受到的转矩相等。同理，若节点数增加，对任意相邻的机械臂进行上述分析，则可以得到多组比例关系，同时满足这些关系即可令各机械臂所受的力矩相同。需要注意的是，最末端的机械臂段因只有被抓取物的惯性作用，其所受力矩总是小于其余的机械臂段。Take a three-joint manipulator as an example, expand the above formula, and calculate the maximum moment received by the No. 1 arm and No. 2 arm. Due to the equal moment, M ₁ =M ₂ , then there are

Since the mass M of the target is much larger than the mass m of the joint 3, it is simplified as

in:

are the lateral acceleration and longitudinal acceleration of the gripper 4 at the end of the manipulator, which can be obtained from the second-order derivation of the abscissa and ordinate of the gripper 4 with respect to time. Note that only the angle changes with time during the derivation process. The length of the arm segment does not change with time, and θ ₁ and its derivatives are both 0, and the rest of the rotation is regarded as a uniform rotation. Will

Substitute into the moment equation and let l ₃ =k ₃ l ₁ =k ₃ l, l ₂ =k ₂ l ₁ =k ₂ l, θ ₃ =Kθ ₂ =Kθ, l be the reference length, θ be the reference angle , then there are

Taking into account the loss of the rotating motor, the rotation of each joint 3 adopts the equiangular principle, that is, K=1; and θ is a known condition, then the relationship between k ₂ and k ₃ can be obtained from the above formula. If the length ratio between the manipulator segments satisfies this relationship, the torques received by the No. 1 arm and No. 2 arm are equal. Similarly, if the number of nodes increases, and the above analysis is performed on any adjacent manipulators, multiple sets of proportional relationships can be obtained, and if these relationships are satisfied at the same time, the torques experienced by each manipulator can be the same. It should be noted that, because only the inertia of the grasped object acts on the last manipulator segment, the moment it receives is always smaller than the rest of the manipulator segments.

As shown in Figure 6, Matlab is used to simulate the maximum moment of each arm segment of the double-joint manipulator. The results show that when l ₂ = 2l ₁ , the maximum moment of arm 1 and arm 2 remain equal at all times, while The moment experienced by arm 3 is always smaller than the rest of the arm segments.

As shown in Figure 7, the length of the last manipulator segment will affect the equal moments of the rest of the manipulators. When the length of the end manipulator segment becomes larger, the ratio of the standard deviation of the torque to the average value of the remaining manipulator segments The smaller it is, the closer the magnitude of the moment is. However, on the other hand, if the length of the end manipulator segment is too large, the torque of the other manipulator segments will increase, making the manipulator as a whole more prone to buckling failure. Therefore, it is necessary to balance the two aspects and choose one Appropriate end arm segment-to-base length ratio. As shown in Figure 5, when l ₃ =7l, the ratio of the standard deviation to the average value is less than 0.05, and it is considered that the torques of the remaining manipulator segments are equal.

The above simulation can be extended to more manipulators with joints 3, and the proportional relationship between each manipulator segment and the reference length can be obtained. Combined with the position information of the target object, the length of each manipulator segment and each joint 3 can be obtained. corner.

Example 2

As shown in Figure 8, it is a cooperative control method between motors when a three-joint space self-growing flexible variable stiffness manipulator is used, that is, three joints 3 are arranged on the manipulator main body 2, and there are four manipulator segments and three bending positions. . The proportional relationship between the lengths of each manipulator segment of the three-joint manipulator is obtained by the simulation of the principle of equal moment as l ₁ =l, l ₂ =1.5l, l ₃ =3.5l, l ₄ =7l. First set the position of the target as (20,-50), and calculate the length and rotation angle of each manipulator segment by the central controller as l ₁ =4.2, l ₂ =6.3, l ₃ =14.7, l ₄ =29.4 , θ ₁ =θ ₂ =θ ₃ =9.59°. The central controller sends instructions to the base 1 and each joint 3, and starts to grow from the robotic arm segment close to the base 1, waits until the arm segment reaches the specified length, and starts the growth of the next arm segment, and grows in turn until the last robotic arm The segment reaches the specified length. During this process, the encoders on the base 1 motor and the joint 3 moving motor feed back the rotation angle of the motor in real time, so as to calculate the corresponding length of the manipulator segment and perform closed-loop control of the motor. The central controller sends bending instructions to each joint 3, and each joint 3 drives the bending motor to bend the joint 3 to a specified angle. During this process, the encoder on the joint 3 bending motor feeds back the rotation angle of the motor in real time, so that the motor forms a closed-loop control. After the bending is completed, the gripper 4 at the end of the robotic arm reaches the position of the target object and grasps the target object. After the grab is completed, input the next target position (-10,-30) to the central controller again, and the length and rotation angle of each manipulator segment calculated by the central controller are l ₁ =2.45, l ₂ =3.675, l ₃ =8.575, l ₄ =17.15, θ ₁ =θ ₂ =θ ₃ =−8.11°. The central controller sends instructions to the base 1 and each joint 3, and starts to shorten from the robotic arm segment close to the base 1. When the arm segment reaches the specified length, the next arm segment is shortened, and shortens in turn until the last robotic arm. The segment reaches the specified length. The central controller sends bending instructions to each joint 3, and each joint 3 drives the bending motor to bend the joint 3 to a specified angle. After the bending is completed, the gripper 4 at the end of the robotic arm and the capture object reach the new target site, completing the transfer of the capture object. Gripper 4 releases the catch, and the robotic arm completes one job.

As shown in Figure 9, after specific experimental simulation, the initial position of the target is (20,-50), the transfer position is (-20,-50), and there is a center position (0,-30) in the middle, and the radius is Under the specific environment setting of obstacles in 5, the above method is run with a total running time of 14s, the attitude information of the manipulator at each key time point is obtained, and finally the target is successfully transported.

Example 3

As shown in Fig. 10, it is a cooperative control method between motors when a six-joint space self-growing flexible variable-stiffness manipulator is used. The six-joint includes two joint main arms I and four joint fine arms II, namely the manipulator main body 2 There are a total of six joints 3 on the upper body, of which the two joints 3 close to the base 1 belong to the main arm I, and the remaining four joints 3 belong to the fine arm II. The proportional relationship between the lengths of each manipulator arm segment of the double-joint main body arm I is obtained through the simulation of the principle of equal moments: l ₁ =l, l ₂ =2l, l ₃ =5l. First, set the center position (20,-50) and shape of the target, and calculate the length and rotation angle of each manipulator segment of the main arm I by the central controller as l ₁ =7.14, l ₂ =14.28, l ₂ =35.7, θ ₁ =θ ₂ =11.15°. The central controller sends instructions to the base 1 and each joint 3, and starts to grow from the robotic arm segment close to the base 1. When the arm segment reaches the specified length, the growth of the next arm segment starts, and grows in turn until the main arm I. The last manipulator segment reaches the specified length. During this process, the encoders on the base 1 motor and the joint 3 moving motor feed back the motor rotation angle in real time, so as to calculate the corresponding length of the manipulator segment and perform closed-loop control of the motor. The central controller sends a bending command to the joint 3 on the main arm I, and each joint 3 drives the bending motor to bend each joint 3 on the main arm I to a specified angle. During this process, the encoder on the bending motor of joint 3 is real-time. Feedback the rotation angle of the motor to form a closed-loop control of the motor. After the bending is completed, the end of the main arm I and the joints 3 of the fine arm II reach the edge of the target. The fine arm II starts to grow according to the specific shape of the target. Each manipulator segment first bends and then stretches. Each motor is also controlled in a closed loop. The fine arm II always grows close to the edge of the target until the last manipulator segment. After completing the growth, the entire fine arm II completes the winding action. Re-input the next target position (5,-10) to the central controller, and the central controller calculates the length and rotation angle of each arm segment of the main arm I as l ₁ =1.43, l ₂ =2.86, l ₃ = 7.15, θ ₁ =θ ₂ =θ ₃ =0°. The central controller sends commands to each joint 3 of the base 1 and the main arm I, and starts to shorten from the robotic arm segment close to the base 1, waits until the arm segment reaches the specified length, and starts to shorten the next arm segment, and shortens in turn until The last arm segment of main arm I has reached the specified length. The central controller sends bending instructions to each joint 3 on the main arm I, and each joint 3 drives the bending motor to bend each joint 3 on the main arm I to a specified angle. During the movement of the main arm I, the fine arm II always keeps the winding motion unchanged. After the main arm I completes the movement, the fine arm II drives the captured objects to a new target site and completes the recovery of the captured objects. The fine arm II is shortened sequentially from the end arm segment. When all the arm segments are contracted, the release of the captured object is completed, and the robotic arm completes a job.

As shown in Figure 11, after the specific experimental simulation, under the specific environment setting that the initial position of the target is (20,-50), the transfer position is (0,-25), and the target is a circle with a radius of 5, the The total running time is 15.5s to run the above method, obtain the attitude information of the manipulator at each key time point, and finally transfer the target successfully.

Compared with the prior art, this method is oriented to the application environment of space orbital garbage capture, and fills the gap in the control strategy of this kind of manipulator in space applications. The maximum moment of the manipulator arm segment is equal, which avoids premature buckling of the manipulator arm segment and improves the overall carrying capacity of the manipulator arm. Two capture strategies, the grabbing strategy and the winding strategy, are proposed for different distances and sizes of space orbital debris, which solves the problem of insufficient adaptability to different types of targets in the current space orbital debris capture.

Taking advantage of the variable length of the flexible and variable stiffness manipulator in space, the principle of equal moment is adopted for the length calculation of each manipulator, so that the maximum moment of each manipulator segment is kept equal, and the local buckling failure of the manipulator is avoided. The overall carrying capacity of the manipulator is improved; this control method is oriented to the capture of orbital garbage in space, adapts to the open and long-distance working environment in space, and has the ability to capture targets in various positions; this control method Meet the requirements of repeated use of the robotic arm.

The above-mentioned specific implementation can be partially adjusted by those skilled in the art in different ways without departing from the principle and purpose of the present invention. The protection scope of the present invention is subject to the claims and is not limited by the above-mentioned specific implementation. Each implementation within the scope is bound by the present invention.

Claims (8)

1. a self-growing flexible variable stiffness manipulator arm space automatic capture control method, characterized in that, comprising: a remote operation mode and an automatic capture mode, wherein: the remote operation mode refers to: by preset each section of the manipulator The length of the main body and the bending angle of each joint are adjusted in real time according to the position of the target, so that the end of the robotic arm can reach the position of the target; automatic capture mode means: first decide to use a grasping strategy or wrapping according to the size of the target strategy, when the volume of the target is within the grasping range of the gripper at the end of the robotic arm, the grasping strategy is adopted, otherwise, the winding strategy is adopted; the distribution of the length of the robotic arm in the grasping or winding strategy adopts the principle of equal maximum torque. 2. The self-growing flexible variable-stiffness manipulator arm according to claim 1, characterized in that the self-growing flexible variable-stiffness manipulator comprises: a central controller, a base, a gripper , The main body of the mechanical arm whose two ends are respectively connected with the base and the gripper, and several joints movably arranged on the main body of the mechanical arm, wherein: the joints move on the main body of the mechanical arm by moving the motor, thereby changing the local rigidity of the main body of the mechanical arm, And the main body of the robotic arm is bent there by bending the motor, and the central controller sends information to the base or joint through the user's input instructions to realize the coordinated control between the motors; The central controller adopts the equiangular principle when calculating the rotation angle of each joint according to the instructions input by the user, so as to ensure that the bending motor losses of each joint are similar, and at the same time, it is beneficial to the equal moment of the manipulator segment; the central controller When calculating the length of the manipulator segment, the principle of equal moment is adopted, that is, try to keep the maximum moment on each manipulator segment equal to avoid local premature buckling, so as to improve the bearing capacity of the whole manipulator. 3. The self-growing flexible variable-stiffness manipulator arm space automatic capture control method according to claim 2, wherein the base and each joint are provided with a local controller, and the local controller comprises: : Power supply unit, communication unit, processing unit, motor unit and sensing unit, wherein: the power supply unit provides energy to the communication unit, processing unit, motor unit and sensing unit respectively through the booster element and the step-down element; the communication unit receives the central The information transmitted by the controller is transmitted to the processing unit. The processing unit converts the information into a level signal and transmits it to the motor unit. The motor unit executes the corresponding rotation according to the received level signal. According to the obtained rotation angle signal, the processing unit performs closed-loop control calculation, and transmits the adjusted level signal to the motor unit. 4. The self-growing flexible variable stiffness manipulator arm space automatic capture control method according to claim 2, wherein the grasping strategy comprises: inputting the position of the target object, calculating the length of the manipulator by the central controller and joint angles, the central controller sends instructions to the base and joints, the base and joints complete corresponding actions and precisely control the movement through position and angle sensors, the end gripper of the robotic arm reaches the target point, implements the grasping action, and the robotic arm Transfer or recovery, end gripper releases target. 5. The self-growing flexible variable-stiffness manipulator arm space automatic capture control method according to claim 2, wherein the winding strategy comprises: dividing the entire manipulator into the position of the target object. The main arm part and the fine arm part for wrapping the target are controlled separately, including: inputting the position and size of the target, the central controller calculating the length and joint angle of the main arm, the central controller sending instructions to the base and joints, The seat and joint complete the corresponding actions and perform closed-loop control through position and angle sensors, the end of the main arm and the fine arm reach the target position, the fine arm implements the winding action according to the shape of the target and is closed-loop controlled by the position and angle sensors, the main arm is transported or Recovery, fine arm recovery and release target. 6. The self-growing flexible variable-stiffness manipulator arm space automatic capture control method according to claim 4 or 5, wherein when a double-joint space self-growing flexible variable-stiffness manipulator is used, the double-joint space self-growing flexible variable-stiffness manipulator is used. The space self-growing flexible variable stiffness manipulator includes two bending positions and three manipulator segments. During the extension and retraction process of the manipulator body, the manipulator segment is not subjected to force in the vertical direction, and no buckling action occurs. The vertical force at the end of each manipulator segment, including: the acceleration at the end of the i-th manipulator segment

The force on the end of each manipulator segment is the sum of the forces on the following manipulators, namely

Among them: the mass corresponding to the endmost manipulator segment is the mass M of the target, and the masses corresponding to the rest of the manipulators are the mass m of the joint. 7. The self-growing flexible variable-stiffness manipulator arm space automatic capture control method according to claim 4 or 5, characterized in that, when a three-joint space self-growing flexible variable-stiffness manipulator is adopted, the manipulator main body There are three joints on it, there are four manipulator segments and three bending positions; the proportional relationship between the lengths of each manipulator segment of the three-joint manipulator is obtained from the simulation of the principle of equal moment: l ₁ =l, l ₂ =1.5l, l ₃ =3.5l, l ₄ =7l; First set the position of the target as (20,-50), and calculate the length and rotation angle of each manipulator segment by the central controller as l ₁ =4.2, l ₂ =6.3, l ₃ =14.7, l ₄ =29.4 , θ ₁ =θ ₂ =θ ₃ =9.59°; the central controller sends instructions to the base and each joint, starting from the robotic arm segment close to base 1, and starting the next arm when the arm segment reaches the specified length The segment grows in turn until the last manipulator segment reaches the specified length. During this process, the encoders on the base motor and the joint movement motor feed back the motor rotation angle in real time, so as to calculate the corresponding length of the manipulator segment. Perform closed-loop control; the central controller sends bending instructions to each joint, and each joint drives the bending motor to bend the joint to a specified angle. During this process, the encoder on the joint bending motor feeds back the motor rotation angle in real time, so that the motor forms a closed-loop control; After the bending is completed, the gripper at the end of the robotic arm reaches the position of the target object and grasps the target object; After the grab is completed, input the next target position (-10,-30) to the central controller again, and the length and rotation angle of each manipulator segment calculated by the central controller are l ₁ =2.45, l ₂ =3.675, l ₃ = 8.575, l ₄ = 17.15, θ ₁ = θ ₂ = θ ₃ = -8.11°; the central controller sends instructions to the base and each joint, starting from the robotic arm segment near the base to shorten, and wait until the arm After the segment reaches the specified length, the shortening of the next arm segment starts, and shortens in turn until the last robotic arm segment reaches the specified length; the central controller sends a bending command to each joint, and each joint drives the bending motor to bend the joint 3 to the specified angle; complete After bending, the gripper and the catch at the end of the robotic arm reach the new target site, completing the transfer of the catch; the gripper releases the catch, and the robotic arm completes one job. 8 . The method for automatically capturing and controlling a space-crossing dimension target of a self-growing flexible variable-stiffness manipulator according to claim 4 or 5, wherein when a six-joint space self-growing flexible variable-stiffness manipulator is adopted, the six-joint comprises: Two joint main body arm I and four joint fine arm II, that is, there are six joints on the main body of the manipulator, of which the two joints near the base belong to the main body arm I, and the remaining four joints belong to the fine arm II; The proportional relationship between the lengths of each manipulator segment of the double-joint main body arm I is obtained from the simulation of the principle of equal moment: l ₁ =l, l ₂ =2l, l ₃ =5l; first set the center position (20,-50) and shape of the target object , the length and rotation angle of each manipulator segment of the main arm I are calculated by the central controller as l ₁ =7.14, l ₂ =14.28, l ₂ =35.7, θ ₁ =θ ₂ =11.15°; The base and each joint send instructions to start the growth from the robotic arm segment close to the base, wait for the arm segment to reach the specified length and start the growth of the next arm segment, and grow in turn until the last robotic arm segment of the main arm I reaches the specified length. During this process, the encoders on the base motor and the joint movement motor feed back the rotation angle of the motor in real time, so as to calculate the corresponding length of the manipulator segment and perform closed-loop control of the motor; the central controller sends the bending angle to the joint on the main arm I command, each joint drives the bending motor to bend each joint on the main arm I to the specified angle. During this process, the encoder on the joint bending motor feeds back the rotation angle of the motor in real time, so that the motor forms a closed-loop control; After the bending is completed, the end of the main arm I and the joints of the fine arm II reach the edge of the target; the fine arm II starts to grow according to the specific shape of the target, and each robotic arm segment first bends and then stretches. , each motor also performs closed-loop control, and the fine arm II always grows close to the edge of the target until the last manipulator segment completes the growth, and the entire fine arm II completes the winding action; Re-input the next target position (5,-10) to the central controller, and the central controller calculates the length and rotation angle of each arm segment of the main arm I as l ₁ =1.43, l ₂ =2.86, l ₃ = 7.15, θ ₁ = θ ₂ = θ ₃ = 0°; the central controller sends commands to each joint of the base and the main arm I, and starts to shorten from the arm segment close to the base, and waits until the arm segment reaches the specified length. Start the shortening of the next arm segment, and shorten in turn until the last robotic arm segment of the main arm I reaches the specified length; the central controller sends bending instructions to each joint on the main arm I, and each joint drives the bending motor to make the main arm I Each joint is bent to a specified angle; during the movement of the main arm I, the fine arm II always keeps the winding motion unchanged. After the main arm I completes the movement, the fine arm II drives the captured object to a new target site and completes the capture The fine arm II is shortened sequentially from the end arm segment, and when all the arm segments are retracted, the release of the captured objects is completed, and the robotic arm completes a job.

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