CN114872938A - Self-growing flexible variable stiffness mechanical arm space cross-size target automatic capture control method - Google Patents
Self-growing flexible variable stiffness mechanical arm space cross-size target automatic capture control method Download PDFInfo
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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
Technical Field
The invention relates to a technology in the field of space technical equipment, in particular to a space cross-size target automatic capture control method of a self-growing flexible stiffness-variable mechanical arm.
Background
The space technology is the crystal developed by human science and technology, is the basis of the vast universe explored by human beings, and the orbital refuse capture technology is a space harmful substance removing or transferring technology which is provided under the condition that the space activities of human beings are more and more frequent and aims at ensuring the safety operation of space personnel and equipment. The existing track garbage capturing technology mainly adopts a rigid mechanical arm or a cable net capturing device. However, the rigid mechanical arm has a short working distance due to the limited length, and is difficult to capture long-distance rail rubbish; the joint position is relatively fixed, and a flexible control strategy is difficult to realize; rigid robotic arms generally carry a gripper at the end to capture the target, but when the target is bulky, the gripper is often insufficient to grasp the target, and therefore they lack a capture strategy for large targets. The cable net capturing device can capture rail rubbish in long distance and various sizes, but is often disposable and not recyclable.
Disclosure of Invention
The invention provides a space cross-size target automatic capture control method of a self-growing flexible variable-stiffness mechanical arm, aiming at the defect that the prior art can only realize the stretching of the space mechanical arm and cannot control the bending of the space mechanical arm, and through the automatic selection of a teleoperation mode or an automatic capture mode, two strategies of capturing and winding are provided aiming at target objects with different sizes, and the conversion between the two strategies does not need to additionally assemble and disassemble additional parts, so that the self-growing flexible variable-stiffness mechanical arm has the characteristics of higher flexibility, larger working range and stronger adaptability, and meanwhile, the self-growing flexible variable-stiffness mechanical arm is adaptive to the space, can be stored, and has light weight, large action range and the like.
The invention is realized by the following technical scheme:
the invention relates to a space span size target automatic capture control method of a self-growing flexible stiffness-variable mechanical arm, which 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 self-growing flexible stiffness-changing mechanical arm comprises: central controller, base, tongs, both ends set up a plurality of joint in the arm main part with arm main part and the activity that base and tongs link to each other respectively, wherein: the joint moves on the mechanical arm main body through the moving motor, so that the local rigidity of the mechanical arm main body is changed, the mechanical arm main body is bent at the position through the bending motor, and the central controller sends information to the base or the joint through an instruction input by a user to realize cooperative control among the motors.
All be equipped with local controller in base and each joint, this local controller includes: power supply unit, communication unit, processing unit, motor element, sensing unit, wherein: the power supply unit provides energy for the communication unit, the processing unit, the motor unit and the sensing unit through the voltage boosting element and the voltage reducing element respectively; the communication unit receives information transmitted by the central controller and transmits the information to the processing unit, the processing unit converts the information into level signals and transmits the level signals to the motor unit, the motor unit executes corresponding rotation according to the received level signals, meanwhile, the sensing unit obtains corresponding corner information according to the actual running condition of the motor unit and transmits the corner information back to the processing unit, and the processing unit performs closed-loop control calculation according to the obtained corner signals and transmits the adjusted level signals to the motor unit.
The grabbing strategy comprises the following steps: inputting the position of a target object, calculating the length and the joint angle of the mechanical arm by the central controller, sending an instruction to the base and the joint by the central controller, finishing corresponding actions by the base and the joint, accurately controlling the movement by the position and angle sensor, enabling the gripper at the tail end of the mechanical arm to reach the target object position, implementing gripping action, transferring or recycling the mechanical arm, and releasing the target object by the gripper at the tail end.
The central controller adopts an equal-angle principle when calculating the rotation angle of each joint according to an instruction input by a user so as to ensure that the loss of a bending motor of each joint is similar and the equal moment of a mechanical arm section is facilitated; when the central controller calculates the length of the mechanical arm sections, an equal moment principle is adopted, namely, the maximum moment received by each mechanical arm section is kept equal as much as possible, and premature buckling is avoided from occurring locally, so that the bearing capacity of the whole mechanical arm is improved.
The winding strategy comprises the following steps: the dividing of the entire robot arm into a main arm portion for reaching a position of the target object and a fine arm portion for winding the target object are controlled separately, including: inputting the position and size of a target object, calculating the length and joint angle of a main body arm by a central controller, sending a command to a base and a joint by the central controller, completing corresponding actions by the base and the joint and performing closed-loop control through a position and angle sensor, enabling the tail end of the main body arm and a fine arm to reach the position of the target object, implementing winding action by the fine arm according to the shape of the target object and performing closed-loop control through the position and angle sensor, operating or recycling the main body arm, and recycling and releasing the target object by the fine arm.
Technical effects
The invention plans the length of the arm section of the self-growing flexible variable-stiffness mechanical arm by using an equal-moment principle, and leads the tail end of the mechanical arm to reach the designated position through the coordination control of the base and the joint motor. Based on the equal-moment principle and motor coordination control, the mechanical arm can be manually operated in real time in a teleoperation mode, or the mechanical arm is automatically planned in an automatic capture mode, in the automatic capture mode, a capture strategy is adopted for small-size targets, and a winding strategy is adopted for large-size targets. The method ensures that the self-growing flexible stiffness-variable mechanical arm avoids premature buckling, and the bearing capacity of the mechanical arm is maximized. The control method adopts different capture modes aiming at space orbit garbage with different distances and sizes, and solves the problem that the adaptability of the space orbit garbage to different types of targets is insufficient in the aspect of space orbit garbage capture at present.
Drawings
FIG. 1 is a schematic view of a spatially self-growing flexible stiffness robotic arm;
FIG. 2 is a flow chart of a control method for a spatially self-growing flexible stiffness robotic arm;
FIG. 3 is a schematic diagram of the cooperative control among motors applied to the control method of the spatial self-growth flexible stiffness-variable mechanical arm;
FIG. 4 is a schematic diagram of a local controller;
FIG. 5 is a schematic diagram of a robotic arm in an equi-torque principle calculation;
FIG. 6 is a diagram of the effect of the equal moment principle;
FIG. 7 is a graph of the effect of end arm segments on the equal moment effect;
FIG. 8 is a schematic view of a gripping strategy of the three-joint mechanical arm according to the embodiment 2;
FIG. 9 is a schematic diagram of a capturing simulation process of the three-joint robot arm shown in time node in example 2;
FIG. 10 is a schematic diagram showing a winding strategy of the double-joint main body arm and the four-joint fine arm in example 3;
FIG. 11 is a schematic diagram of a capturing simulation process of the two-joint main body arm and the four-joint fine arm shown by time nodes in embodiment 3;
in the figure: the robot comprises a base 1, a robot arm body 2, a joint 3, a power supply unit 101, a processing unit 102, a communication unit 103, a motor unit 104, a sensing unit 105, a gripper 4, a main arm I and a fine arm II.
Detailed Description
Example 1
As shown in fig. 1, the present embodiment relates to a spatial self-growing flexible stiffness-varying mechanical arm, which includes: base 1, tongs 4, both ends set up a plurality of joint 3 on arm main part 2 with arm main part 2 and the activity that base 1 and tongs 4 link to each other respectively, wherein: the joint 3 is moved on the robot arm main body 2 by a moving motor, thereby changing the local rigidity of the robot arm main body 2, and the robot arm main body 2 is bent thereat by a bending motor.
The change of the local rigidity of the mechanical arm main body 2 is as follows: the robot arm main body 2 has a certain rigidity in the deployed state, and the rigidity of the robot arm main body 2 is reduced by changing the local conditions on the robot arm main body 2, so that the robot arm main body 2 is more easily bent at the position.
The mechanical arm main body 2 is stored in the base 1 in a winding mode, when a motor on the base 1 rotates, the mechanical arm main body 2 can be driven to extend or retract, wherein the extending part is in an unfolding state, the rigidity is large, the stored part is in a buckling state, and the rigidity is small.
As shown in fig. 2, the method for automatically capturing and controlling a space-span size target based on the self-growth flexible stiffness-variable mechanical arm in the embodiment includes: a teleoperation mode and an automatic acquisition mode, wherein: teleoperation mode refers to: the tail end of the mechanical arm reaches the position of the target object by adjusting the preset length of each section of the mechanical arm main body 2 and the preset bending angle of each joint 3 in real time according to the position of the target object; the automatic capture mode is: firstly, a grabbing strategy or a winding strategy is determined according to the size of the object, if the object is small, the grabbing strategy is adopted, and if the size of the object exceeds the grabbing range of the hand grip 4, the winding strategy is adopted.
As shown in fig. 2, fig. 8 and fig. 9, the grabbing strategy is: firstly, the length of each section of mechanical arm is calculated by a central controller according to an equal moment principle; then sending signals to the base and each joint, and enabling a motor of the base and a moving motor on each joint to act in a synergistic manner, so that the length of each mechanical arm section reaches a specified value; then driving a bending motor at the joint to enable the rotation angle of the joint to reach a specified value, so that the gripper 4 at the tail end of the mechanical arm reaches the position of a target object; after the gripper 4 grips the target, resetting the target position to the central controller; the mechanical arm is transported or recovered to the target position, and the gripper releases the captured object to complete one-time work.
As shown in fig. 2, 10 and 11, the winding strategy is: firstly, growing and bending a main arm I, wherein the process is similar to a grabbing strategy, and firstly, the length of each section of mechanical arm of the main arm I is calculated by a central controller according to an equal moment principle; then, signals are sent to joints of the base and the main body arm I, and a base motor and a moving motor on the main body arm I are enabled to act in a synergistic mode, so that the length of each mechanical arm section of the main body arm I reaches a specified value; then, a bending motor at the joint of the main body arm I is driven to enable the rotation angle of the joint to reach a set value, so that the tail end of the main body arm I and the fine arm II reach the position of a target object; the fine arm II grows and winds at the same time according to the shape of the target object, and at the moment, the moving motor of the main body arm I and the moving motor of the fine arm II need to act in a synergistic mode; after the fine arm II finishes winding action on the target object, resetting the target position to the central controller; the main arm I is transferred or recovered to a target position, and the fine arm II keeps the winding action unchanged; the fine arm II is recovered from the tail end, the captured object is released, and the mechanical arm integrally completes one-time work.
As shown in fig. 3, when the length of a certain arm segment is specified, the motor of the base 1 and the moving motor of each joint 3 need to be cooperatively controlled to make each arm segment reach the specified length. As shown in fig. 3, when the arm i needs to be extended and the length of the remaining arm is not changed, the central controller sends a command to the base 1 and the joint 3 1 to i-1, the motor of the base 1 rotates in the forward direction to unwind the wound robot arm body 2 out of the base 1, the moving motor of the joint 3 1 to i-1 rotates in the reverse direction at the same speed as the motor of the base 1, and the moving motor of the joint 3 i to n does not rotate, so that only the arm i is extended. Similarly, when the arm i needs to be shortened, the motor of the base 1 rotates in the reverse direction, the mechanical arm body 2 which is unfolded is wound and retracted to the base 1, the moving motor of the joint 3 1 to i-1 rotates in the forward direction at the same speed as the motor of the base 1, and the moving motor of the joint 3 to i-n does not rotate, so that only the arm 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 through the voltage boosting component and the voltage dropping component, respectively; the communication unit 103 receives information transmitted by the central controller, transmits the information to the processing unit 102, the processing unit 102 converts the information into a level signal and transmits the level signal to the motor unit 104, the motor unit 104 executes corresponding rotation according to the received level signal, meanwhile, the sensing unit 105 obtains corresponding corner information according to the actual operation condition of the motor unit 104 and transmits the corner information back to the processing unit 102, and the processing unit 102 performs closed-loop control calculation according to the obtained corner signal and transmits the adjusted level signal to the motor unit 104.
As shown in fig. 5-7, the teleoperation mode of the present embodiment employs the equal moment principle, i.e. keeping the maximum moment experienced by each arm segment equal. In the process of computing the equal moment principle, firstly abstracting and assuming the mechanical arm: the mass of the mechanical arm main body 1 is smaller than that of the joint 3, and the mass of the joint 3 is far smaller than that of a target material; ② the joint 3 is regarded as particle; and the first section of the mechanical arm is connected with the base 1 and does not bend.
As shown in fig. 5, in order to implement a cooperative control method between motors when a flexible and rigid robot arm is self-grown in a space with double joints, the base 1, the joints 3, and the grippers 4 are simplified to be circular, and the robot main body 2 is simplified to be a straight line. This double-joint space is from growing flexibility mechanical arm that becomes rigidity includes two crooked positions and three arm sections, and the flexible in-process of arm main part 2, the arm section does not receive the force in the vertical direction, can not take place the bucking action, consequently only considers the terminal perpendicular atress condition of every arm section in the bending process, specifically includes: acceleration of the end of the ith arm segment
The force experienced by the end of each arm segment being the sum of the forces experienced by the subsequent arms, i.e.
Wherein: the mass corresponding to the end-most arm segment is the mass M of the target object, and the masses corresponding to the remaining arms are the masses M of the joints 3.
Taking a three-joint mechanical arm as an example, willThe above equation is developed and the maximum moment received by arm No. 1 and arm No. 2 is calculated, and M is equal to the moment 1 ＝M 2 Then there is
Since the mass M of the target is much larger than the mass M of the joint 3, it is simplified to
Wherein:
the lateral and longitudinal accelerations of the endmost gripper 4 of the robot arm can be obtained by taking the second derivative of the abscissa and ordinate of the gripper 4 with respect to time, noting that only the angle changes with time during the derivative, the length of the arm segments does not change with time, and θ 1 And their derivatives are all 0, the remaining rotations are considered as uniform rotations. Will be provided with
Substituted 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 Where K θ is the reference length, and θ is the reference angle, then
The rotation of each joint 3 adopts the equiangular principle in consideration of the loss of the rotating motorI.e., K ═ 1; and theta is a known condition, then k can be obtained from the above formula 2 And k is 3 The relationship (c) in (c). If the length ratio between the arm segments satisfies this relationship, the torque received by the arm 1 and the arm 2 is equal. Similarly, if the number of nodes is increased, the analysis is performed on any adjacent mechanical arm, so that a plurality of groups of proportional relationships can be obtained, and the moments applied to the mechanical arms can be the same by satisfying the relationships. It should be noted that the moment applied to the endmost arm segment is always less than the other arm segments because the endmost arm segment is only under the inertia of the object being gripped.
As shown in FIG. 6, Matlab is adopted to simulate the maximum torque of each arm segment of the double-joint mechanical arm, and the result shows that 2 ＝2l 1 In the process, the maximum moment borne by the arm No. 1 and the arm No. 2 is kept equal at all times, and the moment borne by the arm No. 3 is always smaller than the rest mechanical arm sections.
As shown in fig. 7, the length of the endmost arm segment affects the equal moment of the remaining arms, and when the length of the endmost arm segment is longer, the ratio of the standard deviation to the average value of the moment applied to the remaining arm segments is smaller, indicating that the magnitude of the moment is closer. On the other hand, if the length of the end arm segment is too large, the moment of the remaining arm segments increases, and the entire robot arm tends to be more susceptible to buckling failure. When l is shown in FIG. 5 3 At 7l, the ratio of the standard deviation to the mean is less than 0.05, and the moments of the remaining arm segments are considered to be equal.
The simulation can be popularized to mechanical arms with more joints 3, the proportional relation between each mechanical arm section and the reference length is obtained, and the length of each mechanical arm section and the rotation angle of each joint 3 can be obtained by combining the position information of the target object.
Example 2
As shown in fig. 8, the method of cooperative control between motors in the case of the spatial self-growth flexible stiffness-variable robot arm using three joints is a method in which three joints 3 are provided on the robot arm main body 2, and four robot arm segments and three bending positions are provided in total. From equi-torque sourcesThe proportional relationship of the lengths of the mechanical arm segments of the three-joint mechanical arm obtained by simulation is l 1 ＝l，l 2 ＝1.5l，l 3 ＝3.5l，l 4 7 l. Firstly, setting the position of a target object to be (20-50), and calculating the length and the rotation angle of each mechanical arm section to be l by a central controller 1 ＝4.2，l 2 ＝6.3，l 3 ＝14.7，l 4 ＝29.4，θ 1 ＝θ 2 ＝θ 3 9.59 deg.. The central controller sends instructions to the base 1 and each joint 3, the arm section close to the base 1 starts to grow, the arm section starts to grow after reaching the specified length, the arm section grows sequentially until the last arm section reaches the specified length, and in the process, encoders on a motor of the base 1 and a motor of the joint 3 move to feed back the rotation angle of the motor in real time, so that the corresponding length of the arm section is calculated, and the motor is subjected to closed-loop control. The central controller sends bending instructions to the joints 3, the joints 3 drive the bending motors to enable the joints 3 to bend to a specified angle, and in the process, encoders on the bending motors of the joints 3 feed back the rotation angles of the motors in real time, so that the motors form closed-loop control. After the bending is completed, the gripper 4 at the end of the mechanical arm reaches the position of the target object, and the target object is gripped. After the grabbing is finished, inputting the next target position (-10, -30) to the central controller again, and calculating by the central controller to obtain the length and the rotation angle of each mechanical arm section as 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 the arm segment close to the base 1 starts to be shortened, and after the arm segment reaches a specified length, the arm segment starts to be shortened next arm segment, and the arm segments are shortened in sequence until the last arm segment reaches the specified length. The central controller sends a bending command to each joint 3, and each joint 3 drives a bending motor to bend the joint 3 to a specified angle. After the bending is completed, the gripper 4 at the end of the mechanical arm and the captured object reach a new target site, and the transfer of the captured object is completed. The gripper 4 releases the captured object and the robot arm completes one job.
As shown in fig. 9, through a specific experimental simulation, under a specific environment setting that the initial position of the target object is (20, -50), the transfer position is (-20, -50), a circle center position (0, -30) exists in the middle, and the obstacle with the radius of 5 exists, the method is operated in the total operation time of 14s, posture information of the mechanical arm at each key time point is obtained, and the target object is successfully transferred finally.
Example 3
As shown in fig. 10, in order to implement a cooperative control method between motors when a six-joint space self-growing flexible stiffness-variable mechanical arm is adopted, the six joints include two joint main body arms i and four joint fine arms ii, that is, six joints 3 are provided on a mechanical arm main body 2, wherein two joints 3 close to a base 1 belong to the main body arms i, and the remaining four joints 3 belong to the fine arms ii. The proportional relation of the lengths of all the mechanical arm sections of the double-joint main body arm I is obtained by equal-moment principle simulation and is l 1 ＝l，l 2 ＝2l，l 3 5 l. Firstly, setting the central position (20-50) and shape of the target object, and calculating the length and the rotation angle l of each mechanical arm section of the main body arm I by a central controller 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, the arm sections close to the base 1 start to grow, the arm sections start to grow after reaching the specified length, the arm sections sequentially grow until the last arm section of the main arm I reaches the specified length, and in the process, encoders on a motor of the base 1 and a motor of the joint 3 move the motor to feed back the rotation angle of the motor in real time, so that the corresponding length of the arm sections is calculated, and the motor is subjected to closed-loop control. The central controller sends bending instructions to the joints 3 on the main body arm I, each joint 3 drives a bending motor, each joint 3 on the main body arm I is bent to a specified angle, and in the process, an encoder on the joint 3 bending motor feeds back the rotation angle of the motor in real time, so that the motor forms closed-loop control. After the bending is completed, the end of the main body arm I and each joint 3 of the fine arm II reach the edge of the target object. The fine arm II starts to grow according to the specific shape of the target object, and each mechanical arm section firstlyAnd (3) performing bending action and then performing extension action, performing closed-loop control on each motor, enabling the fine arm II to grow close to the edge of the target all the time until the last mechanical arm section finishes growing, and finishing winding action on the whole fine arm II. Inputting the next target position (5, -10) to the central controller again, and calculating the length and the rotation angle l of each mechanical arm section of the main body arm I by the central controller 1 ＝1.43，l 2 ＝2.86，l 3 ＝7.15，θ 1 ＝θ 2 ＝θ 3 0 deg.. The central controller sends instructions to the base 1 and each joint 3 of the main body arm I, the arm section close to the base 1 is shortened, the next arm section is shortened after the arm section reaches the designated length, and the arm sections are sequentially shortened until the last arm section of the main body arm I reaches the designated length. The central controller sends bending commands to all joints 3 on the main body arm I, and all the joints 3 drive bending motors to enable all the joints 3 on the main body arm I to bend to a designated angle. In the process of the movement of the main body arm I, the fine arm II always keeps the winding action unchanged, and after the main body arm I finishes the movement, the fine arm II drives the captured object to reach a new target site, so that the captured object is recovered. The fine arm II is sequentially shortened from the tail end arm section, and when all the arm sections are completely contracted, the release of the captured objects is completed, and the mechanical arm completes one-time work.
As shown in fig. 11, through specific experimental simulation, under a specific environment setting that the initial position of the target object is (20, -50), the transfer position is (0, -25), and the target object is a circle with a radius of 5, the above method is operated for a total operation time of 15.5s, so as to obtain attitude information of the mechanical arm at each critical time point, and finally the target object is successfully transferred.
Compared with the prior art, the method is oriented to an application environment of space track garbage capture, fills the gap of the mechanical arm in the aspect of space application control strategies, redistributes the length of the mechanical arm section by utilizing an equal moment principle, enables the maximum moment borne by the mechanical arm section to be equal, avoids premature buckling of the mechanical arm section, and improves the integral bearing capacity of the mechanical arm. Two capture strategies, namely a capture strategy and a winding strategy, are provided aiming at space orbit garbage with different distances and sizes, and the problem that the adaptability of the space orbit garbage to different types of targets is insufficient in the aspect of space orbit garbage capture at present is solved.
The characteristic of variable length of the space self-growing flexible stiffness-variable mechanical arm is utilized, and the equal moment principle is adopted for calculating the length of each section of mechanical arm, so that the maximum moment of each mechanical arm section is kept equal, the local buckling failure of the mechanical arm is avoided, and the integral bearing capacity of the mechanical arm is improved; the control method aims at capturing the orbital rubbish in the space, adapts to the open and long-distance working environment in the space, and has capturing capability on target objects at various positions; the control method meets the requirement of repeated use of the mechanical arm.
The foregoing embodiments may be modified in many different ways by those skilled in the art without departing from the spirit and scope of the invention, which is defined by the appended claims and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
Claims (8)
1. A self-growth flexible variable-stiffness mechanical arm space cross-size target automatic capture control method is characterized by comprising 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.
2. The method as claimed in claim 1, wherein the self-growing flexible stiffness-varying robotic arm comprises: central controller, base, tongs, both ends set up a plurality of joint in the arm main part with arm main part and the activity that base and tongs link to each other respectively, wherein: the joint moves on the mechanical arm main body through the mobile motor, so that the local rigidity of the mechanical arm main body is changed, the mechanical arm main body is bent at the position through the bending motor, and the central controller sends information to the base or the joint through an instruction input by a user to realize cooperative control among the motors;
the central controller adopts an equiangular principle when calculating the corner of each joint according to an instruction input by a user so as to ensure that the loss of a bending motor of each joint is similar and simultaneously facilitate the equiangular moment of the mechanical arm section; when the central controller calculates the length of the mechanical arm sections, an equal moment principle is adopted, namely, the maximum moment received by each mechanical arm section is kept equal as much as possible, and premature buckling is avoided from occurring locally, so that the bearing capacity of the whole mechanical arm is improved.
3. The method as claimed in claim 2, wherein a local controller is provided in each of the base and each joint, the local controller comprising: power supply unit, communication unit, processing unit, motor element and sensing unit, wherein: the power supply unit provides energy for the communication unit, the processing unit, the motor unit and the sensing unit through the voltage boosting element and the voltage reducing element respectively; the communication unit receives information transmitted by the central controller and transmits the information to the processing unit, the processing unit converts the information into level signals and transmits the level signals to the motor unit, the motor unit executes corresponding rotation according to the received level signals, meanwhile, the sensing unit obtains corresponding corner information according to the actual running condition of the motor unit and transmits the corner information back to the processing unit, and the processing unit performs closed-loop control calculation according to the obtained corner signals and transmits the adjusted level signals to the motor unit.
4. The method for controlling automatic capture of space-span dimensional targets of a self-growing flexible stiffness-varying mechanical arm according to claim 2, wherein the capture strategy comprises: inputting the position of a target object, calculating the length and the joint angle of the mechanical arm by the central controller, sending an instruction to the base and the joint by the central controller, finishing corresponding actions by the base and the joint, accurately controlling the movement by the position and angle sensor, enabling the gripper at the tail end of the mechanical arm to reach the target object position, implementing gripping action, transferring or recycling the mechanical arm, and releasing the target object by the gripper at the tail end.
5. The method of claim 2, wherein the wrapping strategy comprises: the dividing of the entire robot arm into a main arm portion for reaching a position of the target object and a fine arm portion for winding the target object are controlled separately, including: inputting the position and size of a target object, calculating the length and joint angle of a main body arm by a central controller, sending a command to a base and a joint by the central controller, completing corresponding actions by the base and the joint and performing closed-loop control through a position and angle sensor, enabling the tail end of the main body arm and a fine arm to reach the position of the target object, implementing winding action by the fine arm according to the shape of the target object and performing closed-loop control through the position and angle sensor, operating or recycling the main body arm, and recycling and releasing the target object by the fine arm.
6. The method for automatically capturing and controlling the cross-dimensional target of the self-growing flexible stiffness-changing mechanical arm space according to claim 4 or 5, wherein when the double-joint space self-growing flexible stiffness-changing mechanical arm is adopted, the double-joint space self-growing flexible stiffness-changing mechanical arm comprises two bending positions and three mechanical arm sections, and in the stretching and retracting process of the mechanical arm main body, no force is applied to the mechanical arm sections in the vertical direction, and no buckling action occurs, so that only the vertical force application condition of the tail end of each mechanical arm section in the bending process is considered, and the method specifically comprises the following steps: acceleration of the end of the ith arm segment
The force experienced by the end of each arm segment being the sum of the forces experienced by the subsequent arms, i.e.
Wherein: the mass corresponding to the mechanical arm section at the tail end is the mass M of the target object, and the masses corresponding to the other mechanical arms are the masses M of the joints.
7. The method for automatically capturing and controlling the space span size target of the self-growing flexible stiffness-variable mechanical arm according to claim 4 or 5, wherein when a three-joint space self-growing flexible stiffness-variable mechanical arm is adopted, namely a mechanical arm main body is provided with three joints, and four mechanical arm sections and three bending positions are provided in total; the proportional relation of the lengths of all the mechanical arm segments of the three-joint mechanical arm is obtained by equal-moment principle simulation and is l 1 ＝l，l 2 ＝1.5l，l 3 ＝3.5l，l 4 ＝7l；
Firstly, setting the position of a target object to be (20-50), and calculating the length and the rotation angle of each mechanical arm section to be l by a central controller 1 ＝4.2，l 2 ＝6.3，l 3 ＝14.7，l 4 ＝29.4，θ 1 ＝θ 2 ＝θ 3 9.59 °; sending instructions to the base and each joint by the central controller, starting to grow from the mechanical arm section close to the base 1, starting to grow the next arm section after the arm section reaches the specified length, and sequentially growing until the last mechanical arm section reaches the specified length; the central controller sends bending instructions to each joint, each joint drives a bending motor to bend the joint to a specified angle, and an encoder on the joint bending motor feeds back the rotation angle of the motor in real time in the process to enable the motor to form closed-loop control; after the bending is finished, the gripper at the tail end of the mechanical arm reaches the position of the target object, and the target object is gripped;
after the grabbing is finished, inputting the next target position (-10, -30) to the central controller again, and calculating by the central controller to obtain the length and the rotation angle of each mechanical arm section as l 1 ＝2.45，l 2 ＝3.675，l 3 ＝8.575，l 4 ＝17.15，θ 1 ＝θ 2 ＝θ 3 -8.11 °; sending instructions to the base and each joint by the central controller, shortening from the mechanical arm section close to the base, starting to shorten the next arm section after the arm section reaches the specified length, and shortening sequentially until the last mechanical arm section reaches the specified length; the central controller sends bending instructions to each joint, and each joint drives a bending motor to bend the joint 3 to a specified angle; after the bending is finished, the hand grip at the tail end of the mechanical arm and the captured object reach a new target site, and the captured object is transferred; the gripper releases the captured object and the mechanical arm completes one operation.
8. The method for automatically capturing and controlling the space span size target of the self-growing flexible rigidity-variable mechanical arm according to claim 4 or 5, wherein when the self-growing flexible rigidity-variable mechanical arm with six joints is adopted, the six joints comprise two joint main body arms I and four joint fine arms II, namely, six joints are arranged on the mechanical arm main body, wherein two joints close to the base belong to the main body arms I, and the other four joints belong to the fine arms II; the proportional relation of the lengths of all the mechanical arm sections of the double-joint main body arm I is obtained by equal-moment principle simulation and is l 1 ＝l，l 2 ＝2l，l 3 5 l; firstly, setting the central position (20-50) and shape of the target object, and calculating the length and the rotation angle l of each mechanical arm section of the main body arm I by a central controller 1 ＝7.14，l 2 ＝14.28，l 2 ＝35.7，θ 1 ＝θ 2 11.15 °; sending instructions to the base and each joint by the central controller, starting to grow from the mechanical arm section close to the base, starting to grow the next arm section after the arm section reaches the specified length, and sequentially growing until the last arm section of the main arm I reaches the specified length; the central controller sends bending commands to joints on the main body arm I, and each joint drives a bending motorThe joint bending machine enables each joint on the main body arm I to be bent to a specified angle, and in the process, an encoder on the joint bending motor feeds back the rotation angle of the motor in real time to enable the motor to form closed-loop control;
after the bending is finished, the tail end of the main body arm I and each joint of the fine arm II reach the edge of the target object; the fine arm II starts to grow according to the specific shape of the target object, each mechanical arm section firstly carries out bending action and then carries out stretching action, each motor also carries out closed-loop control, the fine arm II always grows close to the edge of the target object until the last mechanical arm section finishes growing, and the whole fine arm II finishes winding action;
inputting the next target position (5, -10) to the central controller again, and calculating the length and the rotation angle l of each mechanical arm section of the main body arm I by the central controller 1 ＝1.43，l 2 ＝2.86，l 3 ＝7.15，θ 1 ＝θ 2 ＝θ 3 0 °; sending instructions to each joint of the base and the main body arm I by the central controller, starting to shorten from a mechanical arm section close to the base, starting to shorten the next arm section after the arm section reaches a specified length, and sequentially shortening until the last mechanical arm section of the main body arm I reaches the specified length; the central controller sends bending instructions to all joints on the main body arm I, and all joints drive a bending motor to enable all joints on the main body arm I to bend to a specified angle; in the process of movement of the main body arm I, the fine arm II always keeps constant winding action, and after the main body arm I finishes movement, the fine arm II drives the captured object to reach a new target site, so that the captured object is recovered; the fine arm II is sequentially shortened from the tail end arm section, and when all the arm sections are completely contracted, the release of the captured objects is completed, and the mechanical arm completes one-time work.
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Citations (26)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05228854A (en) * | 1992-02-18 | 1993-09-07 | Fujitsu Ltd | Method for controlling arm having 7 degree of freedom |
| US5575764A (en) * | 1994-12-14 | 1996-11-19 | Van Dyne; Leonard A. | Prosthetic joint with dynamic torque compensator |
| DE19819858A1 (en) * | 1998-05-04 | 1999-11-11 | Oskar Bschorr | Flexible tether manipulator system for space satellite |
| JP2000190265A (en) * | 1998-12-21 | 2000-07-11 | Natl Space Development Agency Of Japan | Reconfiguration type space multiple manipulator system |
| US20030146720A1 (en) * | 2000-06-21 | 2003-08-07 | Alain Riwan | Control arm with two parallel branches |
| US20110121139A1 (en) * | 2009-11-25 | 2011-05-26 | Poulos Air & Space | Stabilization of unstable space debris |
| JP2011125956A (en) * | 2009-12-17 | 2011-06-30 | Denso Wave Inc | Method and device for identifying spring constant of robot |
| JP2011252508A (en) * | 2011-09-21 | 2011-12-15 | Nissan Motor Co Ltd | Variable compression ratio internal combustion engine |
| WO2013007039A1 (en) * | 2011-07-14 | 2013-01-17 | 长沙中联重工科技发展股份有限公司 | Mechanical arm control method and device and engineering machinery |
| KR101478447B1 (en) * | 2013-07-01 | 2014-12-31 | 고려대학교 산학협력단 | Controllable rotational stiffness actuator using variating moment arm |
| US20160077261A1 (en) * | 2014-09-15 | 2016-03-17 | California Institute Of Technology | Simultaneous polarization and wavefront control using a planar device |
| EP3112274A1 (en) * | 2015-07-01 | 2017-01-04 | Thales | Spatial system for reducing the angular velocities of space debris before removing same from orbit |
| US20180148197A1 (en) * | 2014-08-26 | 2018-05-31 | Effective Space Solutions Ltd. | Docking system and method for satellites |
| CN108400552A (en) * | 2017-10-27 | 2018-08-14 | 广东电网有限责任公司揭阳供电局 | A kind of electric line foreign matter remove device being provided with balance component |
| CN108942906A (en) * | 2018-08-01 | 2018-12-07 | 清华大学深圳研究生院 | flexible mechanical arm and system |
| CN109079760A (en) * | 2018-09-12 | 2018-12-25 | 哈尔滨工业大学（深圳） | A kind of curved space truss break catching apparatus of telescopic |
| CN109250156A (en) * | 2018-07-24 | 2019-01-22 | 西北工业大学 | A kind of space non-cooperative target electromagnetic eddy racemization break catching apparatus and method |
| CN109606753A (en) * | 2018-11-11 | 2019-04-12 | 上海宇航系统工程研究所 | A kind of control method of Dual-arm space robot collaboration capture target |
| CN109822554A (en) * | 2019-03-20 | 2019-05-31 | 华中科技大学 | Towards underwater both arms collaboration crawl, embraces and take and collision prevention integral method and system |
| US20190328480A1 (en) * | 2016-09-13 | 2019-10-31 | Sony Corporation | Medical support arm apparatus, medical system, and surgical microscope system |
| CN110979756A (en) * | 2019-12-20 | 2020-04-10 | 哈尔滨工业大学（深圳） | Space-expandable catching manipulator device |
| CN111390872A (en) * | 2020-03-19 | 2020-07-10 | 上海航天控制技术研究所 | Double-arm cooperative flexible dragging and butt joint inverse operation method for extravehicular robot |
| CN111673780A (en) * | 2020-06-08 | 2020-09-18 | 鹏城实验室 | Multi-dimensional adaptive space-winding arm and capturing device |
| US20200298403A1 (en) * | 2016-03-29 | 2020-09-24 | Cognibotics Ab | Method, constraining device and system for determining geometric properties of a manipulator |
| CN113524160A (en) * | 2021-07-20 | 2021-10-22 | 哈尔滨工业大学 | Momentum self-adaptive isolation slow-release type space capturing device |
| CN114012711A (en) * | 2021-11-23 | 2022-02-08 | 湖北工业大学 | Outdoor facility installation mechanical arm designed based on touch grabbing tightness |
-
2022
- 2022-05-12 CN CN202210537085.1A patent/CN114872938A/en active Pending
Patent Citations (27)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05228854A (en) * | 1992-02-18 | 1993-09-07 | Fujitsu Ltd | Method for controlling arm having 7 degree of freedom |
| US5575764A (en) * | 1994-12-14 | 1996-11-19 | Van Dyne; Leonard A. | Prosthetic joint with dynamic torque compensator |
| DE19819858A1 (en) * | 1998-05-04 | 1999-11-11 | Oskar Bschorr | Flexible tether manipulator system for space satellite |
| JP2000190265A (en) * | 1998-12-21 | 2000-07-11 | Natl Space Development Agency Of Japan | Reconfiguration type space multiple manipulator system |
| US20030146720A1 (en) * | 2000-06-21 | 2003-08-07 | Alain Riwan | Control arm with two parallel branches |
| US20110121139A1 (en) * | 2009-11-25 | 2011-05-26 | Poulos Air & Space | Stabilization of unstable space debris |
| JP2011125956A (en) * | 2009-12-17 | 2011-06-30 | Denso Wave Inc | Method and device for identifying spring constant of robot |
| WO2013007039A1 (en) * | 2011-07-14 | 2013-01-17 | 长沙中联重工科技发展股份有限公司 | Mechanical arm control method and device and engineering machinery |
| JP2011252508A (en) * | 2011-09-21 | 2011-12-15 | Nissan Motor Co Ltd | Variable compression ratio internal combustion engine |
| KR101478447B1 (en) * | 2013-07-01 | 2014-12-31 | 고려대학교 산학협력단 | Controllable rotational stiffness actuator using variating moment arm |
| US20180148197A1 (en) * | 2014-08-26 | 2018-05-31 | Effective Space Solutions Ltd. | Docking system and method for satellites |
| US20160077261A1 (en) * | 2014-09-15 | 2016-03-17 | California Institute Of Technology | Simultaneous polarization and wavefront control using a planar device |
| EP3112274A1 (en) * | 2015-07-01 | 2017-01-04 | Thales | Spatial system for reducing the angular velocities of space debris before removing same from orbit |
| US20200298403A1 (en) * | 2016-03-29 | 2020-09-24 | Cognibotics Ab | Method, constraining device and system for determining geometric properties of a manipulator |
| US20190328480A1 (en) * | 2016-09-13 | 2019-10-31 | Sony Corporation | Medical support arm apparatus, medical system, and surgical microscope system |
| CN108400552A (en) * | 2017-10-27 | 2018-08-14 | 广东电网有限责任公司揭阳供电局 | A kind of electric line foreign matter remove device being provided with balance component |
| CN109250156A (en) * | 2018-07-24 | 2019-01-22 | 西北工业大学 | A kind of space non-cooperative target electromagnetic eddy racemization break catching apparatus and method |
| CN108942906A (en) * | 2018-08-01 | 2018-12-07 | 清华大学深圳研究生院 | flexible mechanical arm and system |
| CN109079760A (en) * | 2018-09-12 | 2018-12-25 | 哈尔滨工业大学（深圳） | A kind of curved space truss break catching apparatus of telescopic |
| CN109606753A (en) * | 2018-11-11 | 2019-04-12 | 上海宇航系统工程研究所 | A kind of control method of Dual-arm space robot collaboration capture target |
| CN109822554A (en) * | 2019-03-20 | 2019-05-31 | 华中科技大学 | Towards underwater both arms collaboration crawl, embraces and take and collision prevention integral method and system |
| CN110979756A (en) * | 2019-12-20 | 2020-04-10 | 哈尔滨工业大学（深圳） | Space-expandable catching manipulator device |
| CN111390872A (en) * | 2020-03-19 | 2020-07-10 | 上海航天控制技术研究所 | Double-arm cooperative flexible dragging and butt joint inverse operation method for extravehicular robot |
| CN111673780A (en) * | 2020-06-08 | 2020-09-18 | 鹏城实验室 | Multi-dimensional adaptive space-winding arm and capturing device |
| WO2021248684A1 (en) * | 2020-06-08 | 2021-12-16 | 鹏城实验室 | Multi-dimensional, space-adaptive winding arm and capture device |
| CN113524160A (en) * | 2021-07-20 | 2021-10-22 | 哈尔滨工业大学 | Momentum self-adaptive isolation slow-release type space capturing device |
| CN114012711A (en) * | 2021-11-23 | 2022-02-08 | 湖北工业大学 | Outdoor facility installation mechanical arm designed based on touch grabbing tightness |
Non-Patent Citations (2)
| Title |
|---|
| 介党阳;倪风雷;谭益松;刘宏;蔡鹤皋;: "基于分布式控制系统的空间大型末端执行器抓捕策略", 机器人, no. 04, 15 July 2011 (2011-07-15), pages 434 - 439 * |
| 魏承;赵阳;王洪柳;: "基于滑模控制的空间机器人软硬性抓取", 机械工程学报, no. 01, 5 January 2011 (2011-01-05), pages 43 - 47 * |
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