A coordinated control method for a dual-arm robot

Abstract

The present invention discloses a method for coordinated control of a dual-arm robot. Based on the characteristic of a closed-chain parallel structure formed when the dual arms are tightly coordinated, the method proposes a method of optimizing the input pair and degenerating the remaining kinematic pairs into passive pairs. This method can effectively reduce the difficulty of coordinated control of the dual arms and has good versatility. By adopting the control method of the present invention, not only can the movement of fewer kinematic pairs be controlled to achieve precise operation of the robot, but the effective utilization of the force driving the passive pair and the transmission quality of the mechanism can also be improved. By optimizing the optimal input combination obtained, the speed fluctuation of the dual-arm robot movement is reduced, and the robot movement is more stable.

Description

Technical Field

[0001] The present invention belongs to the technical field of robots, and in particular relates to a coordinated control method for a dual-arm robot. Background Art

[0002] Robots have been widely used in various industries and fields in production and daily life. Single-arm robots are currently widely used in the manufacturing field, and are well-suited for tasks such as handling, palletizing, welding, assembly, and spraying. Handling and welding are particularly important. Compared to single-arm robots, dual-arm robots are more than just two robotic arms combined; they achieve tasks and work together through coordinated constraints and coordinated control.

[0003] Coordinated operation of dual-arm robots can be categorized as loose coordination and tight coordination. Loose coordination refers to a dual-arm robot performing independent tasks within the same workspace. Tight coordination involves a dual-arm robot performing the same task within the same workspace. Each arm directly contacts the object being manipulated, forming a closed-loop mechanism and generating force through the end-effector. This increases the robot's stiffness and strength while maintaining its flexibility. Common control approaches for achieving dual-arm coordination include master-slave control, decentralized control, and centralized control. In the master-slave control model, the two arms are defined as a master and a slave. The master arm typically uses position control and follows a specific trajectory, while the slave arm uses force control to maintain kinematic constraints between the arms and the object and follow the movements of the master arm. However, due to the lag in force tracking, true coordination is difficult to achieve in tightly constrained scenarios. In the centralized control model, the dual-arm robot operates as a single unit, with a single controller controlling both arms. This shared controller must address planning, control, and coordination, as well as process information from various external sensors, resulting in a high computational load. In the decentralized control mode, the force required to grasp an object is distributed to the left and right arms based on their respective load capacities. The left arm controller is then designed separately based on the motion of the left arm and the object, and the right arm controller is designed separately based on the motion of the right arm and the object. Decentralized control uses load distribution to decompose the dual-arm collaborative control problem into the control design of a single robotic arm, but the challenge is how to distribute the grasping force of the two arms in real time based on the load motion. Furthermore, existing dual-arm collaborative control methods suffer from high model dependence, low position control accuracy, and the ability to only address the control of a single external force, internal force, or contact force. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides a coordinated control method for a dual-arm robot. This method can not only control fewer motion sub-motions to achieve precise operation of the robot, but also solve problems such as uneven load force distribution and lagging of the slave arm in the tight coordinated control of the dual-arm robot.

[0005] The technical solution of the present invention to solve the technical problem is to design a dual-arm robot coordinated control method, which is characterized in that the method is suitable for tight coordination of dual arms and includes the following steps:

[0006] Step 1: Tight coordination of dual arms requires that the dual-arm robot has a strict motion constraint relationship. The grasped object and the robot's dual arms form a complete closed-chain structure, forming a parallel mechanism; Definition: T} is the coordinate system of the center of mass of the grasped object, {O T1}、{O T2} are the tool coordinate systems of the manipulators R1 and R2, {O} is the base coordinate system of the dual-arm robot, and {O1} and {O2} are the base coordinate systems of the manipulators R1 and R2, respectively;

[0007] Step 2: Kinematic modeling of the dual-arm robot based on the screw theory:

[0008]

[0009]

[0010] in, is the kinematic rotation of each kinematic pair in the robot R1, and n is the number of kinematic pairs in the robot R1; is the kinematic rotation of each kinematic pair in the manipulator R2, m is the number of kinematic pairs in the manipulator R2; [L i M i N i P i Q i R i ] for sports associate Plücker coordinate expression, when the kinematic pair When L is the moving pair, i 、M i 、N i Both are 0, P i , Q i 、R i Deputy Sports Representative The axis direction vector of the components in the X, Y, and Z axes; when the kinematic pair For a rotating pair, L i 、M i 、N i Deputy Sports Representative The components of the axis direction vector in the X, Y, and Z axes, P i , Q i 、R i Deputy Sports Representative The components of the linear moment of the axis direction vector about the origin in the X, Y, and Z axes; Represents any kinematic pair in the robot arm R1 or the robot arm R2;

[0011] Step 3: Use the input selection method to obtain all reasonable input combinations of the dual-arm robot; the input selection method is: when all active pairs are locked, the mechanism loses all degrees of freedom and cannot move, and the drive input is reasonable, otherwise it is unreasonable; therefore, when selecting the input for the dual arms, select a certain kinematic pair in each branch and assume that it is rigidified, and then analyze the constrained spiral system of the dual-arm robot at this time. If the maximum linear independent number of the constrained spiral system is 6 at this time, the dual-arm robot loses all degrees of freedom and the input selection is reasonable; if the maximum linear independent number is less than 6, the dual-arm robot cannot lose all degrees of freedom, and there are still uncontrollable degrees of freedom, and the input selection is unreasonable; arbitrarily select a number of kinematic pairs in the dual-arm robot as a combination, and all combinations that meet the input selection method and have the same number of kinematic pairs selected on the manipulators R1 and R2 are reasonable input combinations;

[0012] Step 4: According to the working conditions of the dual-arm robot, the motion constraint relationship of the dual-arm robot is determined as follows:

[0013]

[0014]

[0015] in For the coordinate system {O T} in the coordinate system {O}, is the pose of coordinate system {O1} in coordinate system {O}, For the coordinate system {O T1} in the coordinate system {O1}, For the coordinate system {O T}In the coordinate system {O T1}, is the position of coordinate system {O2} in coordinate system {O}, For the coordinate system {O T2} in the coordinate system {O2}, For the coordinate system {O T}In the coordinate system {O T2} in the pose;

[0016] In formula (3) and formula (4), and It is related to the installation method of the manipulators R1 and R2, which are all known. When the expected position of the grasped object is known, When the constraint relationship is used, the position of the end of the manipulator R1 and R2 relative to the base is obtained. for:

[0017]

[0018]

[0019] After the specific configurations of the manipulators R1 and R2 are known, the forward kinematics and inverse kinematics equations of the manipulators R1 and R2 are obtained;

[0020] Step 5: Using load-bearing performance as the evaluation index, select the optimal input combination from all reasonable input combinations of the dual-arm robot obtained in step 3; the evaluation index is:

[0021]

[0022] Among them, n is the total number of samples uniformly selected on the working trajectory of the grasped object, S 2 is the sample variance, μ is the sample mean, Q is the total variance of a reasonable input combination, representing the sum of the variances of all angular accelerations of the input combination, and a is the sample value, representing the angular acceleration of an input kinematic pair, which is calculated by formula (6):

[0023]

[0024] where t m is the time from the m+1th sample point to the mth sample point, ω(i,j) and a(i,j) are the angular velocity and angular acceleration of the i-th kinematic pair of the j-th manipulator during this period, respectively. m 、Py m 、Pz m are the expected position of the mth sample point, θ(i,j) is the i-th kinematic angle of the j-th manipulator, and v is the assumed speed of the object being rotated, v = 0.1 m / s;

[0025] The smaller the total variance Q of each input combination, the smaller the fluctuation of the speed of the input scheme, the better the motion performance of the dual-arm robot, and the combination with the smallest Q value is selected as the optimal input combination;

[0026] Step 6: Use the kinematic pair in the optimal input combination obtained in step 5 as the input pair, and the remaining kinematic pairs in the dual-arm robot as passive pairs. Adjust the rotation angle of the input pair to achieve tight coordinated operation control of the dual-arm robot's two arms.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows: a dual-arm robot coordinated control method designed by the present invention, based on the characteristic of forming a closed-chain parallel structure when the two arms are tightly coordinated, proposes a method of degenerating the remaining motion pairs into passive pairs by optimizing the input pair, which can effectively reduce the difficulty of dual-arm coordinated control and has good versatility. By adopting the control method of the present invention, not only can the precise operation of the robot be achieved by controlling the movement of fewer motion pairs, but also the effective utilization of the force driving the passive pair and the transmission quality of the mechanism can be improved. The optimal input combination obtained by optimization makes the speed fluctuation of the dual-arm robot movement smaller and the movement of the robot more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the coordinate system setting of a dual-arm robot according to an embodiment of a dual-arm robot coordinated control method of the present invention.

[0029] Figure 2 The figure is a schematic flow chart of the steps of an embodiment of a coordinated control method of a dual-arm robot according to the present invention.

[0030] Figure 3 This is a schematic diagram of the structure of a 2-RPPPS dual-arm robot in an embodiment of a dual-arm robot coordinated control method of the present invention.

[0031] Figure 4 This is a diagram of the angular acceleration of some kinematic pairs (joints) of a 2-RPPPS dual-arm robot when the optimal input combination is selected in an embodiment of a dual-arm robot coordinated control method of the present invention; wherein, Figure 4 (a) is the angular acceleration diagram of the first, fifth, sixth and seventh kinematic pairs of the robot arm R1. Figure 4 (b) is the angular acceleration diagram of the second, third and fourth kinematic pairs of the robot arm R1. Figure 4 (c) in the figure is the angular acceleration diagram of the first, fifth, sixth and seventh kinematic pairs of the robot arm R2. Figure 4 (d) in the figure is the angular acceleration diagram of the second, third and fourth kinematic pairs of the robot arm R2. DETAILED DESCRIPTION

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

[0033] The present invention provides a dual-arm robot coordinated control method, which is applicable to a dual-arm coordinated operation (i.e., a scenario in which both arms of a dual-arm robot jointly grasp an object). The method comprises the following steps:

[0034] Step 1: Tight coordination of dual arms requires that the dual-arm robot has a strict motion constraint relationship. The grasped object and the robot's dual arms form a complete closed-chain structure, forming a parallel mechanism. T} is the coordinate system of the center of mass of the grasped object, {O T1}、{O T2} are the tool coordinate systems of the manipulators R1 and R2, {O} is the base coordinate system of the dual-arm robot, and {O1} and {O2} are the base coordinate systems of the manipulators R1 and R2, respectively. Figure 1 shown.

[0035] Step 2: Kinematic modeling of the dual-arm robot based on the screw theory:

[0036]

[0037]

[0038] in is the kinematic rotation of each kinematic pair in the robot R1, and n is the number of kinematic pairs in the robot R1; is the kinematic rotation of each kinematic pair in the manipulator R2, and m is the number of kinematic pairs in the manipulator R2. i M i N i P i Q i R i ] for sports associate Plücker coordinate expression, when the kinematic pair When L is the moving pair, i 、M i 、N i Both are 0, P i , Q i 、R i Deputy Sports Representative The axis direction vector of the components in the X, Y, and Z axes; when the kinematic pair For a rotating pair, L i 、M i 、N i Deputy Sports Representative The components of the axis direction vector in the X, Y, and Z axes, P i , Q i 、R i Deputy Sports Representative The components of the linear moment of the axis direction vector about the origin in the X, Y, and Z axes. Represents any kinematic pair in robot arm R1 or robot arm R2.

[0039] Step 3: Use the input selection method to obtain all reasonable input combinations for the dual-arm robot. The input selection method is as follows: when all active pairs are locked, the mechanism loses all degrees of freedom and cannot move. The drive input is reasonable; otherwise, it is unreasonable. Therefore, when selecting input for the dual-arm, select a kinematic pair from each branch and assume it is rigid. Then analyze the constrained screw system of the dual-arm robot at this time. If the maximum linearly independent number of the constrained screw system is 6, the dual-arm robot loses all degrees of freedom and the input selection is reasonable. If the maximum linearly independent number is less than 6, the dual-arm robot cannot lose all degrees of freedom and still has uncontrollable degrees of freedom, and the input selection is unreasonable. Randomly select a number of kinematic pairs in the dual-arm robot as a combination. All combinations that meet the input selection method and have the same number of kinematic pairs selected on manipulators R1 and R2 are reasonable input combinations.

[0040] Step 4: According to the working conditions of the dual-arm robot, the motion constraint relationship of the dual-arm robot is determined as follows:

[0041]

[0042]

[0043] in For the coordinate system {O T} in the coordinate system {O}, is the pose of coordinate system {O1} in coordinate system {O}, For the coordinate system {O T1} in the coordinate system {O1}, For the coordinate system {O T}In the coordinate system {O T1}, is the position of coordinate system {O2} in coordinate system {O}, For the coordinate system {O T2} in the coordinate system {O2}, For the coordinate system {O T}In the coordinate system {O T2} in the pose.

[0044] In formula (3) and formula (4), and It is related to the installation method of the manipulators R1 and R2, which are all known. When the expected position of the grasped object is known, When the constraint relationship is used, the position of the end of the manipulator R1 and R2 relative to the base is obtained. for:

[0045]

[0046]

[0047] After the specific configurations of the robotic arms R1 and R2 are known, the forward kinematics and inverse kinematics equations of the robotic arms R1 and R2 are obtained.

[0048] Step 5: Using load-bearing performance as the evaluation index, select the optimal input combination from all reasonable input combinations of the dual-arm robot obtained in step 3. The evaluation index is:

[0049]

[0050] Among them, n is the total number of samples uniformly selected on the working trajectory of the grasped object, S 2 is the sample variance, μ is the sample mean, Q is the total variance of a reasonable input combination, representing the sum of the variances of all angular accelerations of the input combination, and a is the sample value, representing the angular acceleration of an input kinematic pair, which is calculated by formula (6):

[0051]

[0052] where t m is the time from the m+1th sample point to the mth sample point, ω(i,j) and a(i,j) are the angular velocity and angular acceleration of the i-th kinematic pair of the j-th manipulator during this period, respectively. m 、Py m 、Pz m are the positions of the mth sample point expected to arrive, θ(i,j) is the i-th kinematic angle of the j-th robotic arm, and v is the assumed speed of the object being rotated, v = 0.1 m / s.

[0053] The smaller the total variance Q of each input combination, the smaller the fluctuation of the speed of the input scheme, the better the motion performance of the dual-arm robot, and the combination with the smallest Q value is selected as the optimal input combination.

[0054] Step 6: Use the kinematic pair in the optimal input combination obtained in step 5 as the input pair, and the remaining kinematic pairs in the dual-arm robot as passive pairs. Adjust the rotation angle of the input pair to achieve tight coordinated operation control of the dual-arm robot's two arms.

[0055] A 2-RPPPS dual-arm robot is selected as an example to describe the method of the present invention in detail. Other parallel robots can also be applied according to the above method.

[0056] This embodiment provides a dual-arm robot coordinated control method, which is suitable for dual-arm tight coordinated operation, and includes the following steps:

[0057] Step 1: Tight coordination of dual arms requires that the dual-arm robot has a strict motion constraint relationship. The grasped object and the robot's dual arms form a complete closed-chain structure, forming a parallel mechanism. T} is the coordinate system of the center of mass of the grasped object, {O T1}、{O T2} are the tool coordinate systems of the manipulators R1 and R2, {O} is the base coordinate system of the dual-arm robot, and {O1} and {O2} are the base coordinate systems of the manipulators R1 and R2, respectively;

[0058] Step 2: Kinematic modeling of the 2-RPPPS dual-arm robot based on the screw theory:

[0059]

[0060]

[0061] in is the kinematic rotation of each kinematic pair in the robot arm R1, is the kinematic rotation of each kinematic pair in the manipulator R2. In the 2-RPPPS dual-arm robot, the number of kinematic pairs of both manipulators is 17; in formula (7) For the moving pair, the first three columns are all 0, and the last three columns are the components of its axis direction vector in the X, Y, and Z axes. is a revolute pair. The first three columns are the components of its axis direction vector in the X, Y, and Z axes. The last three columns are the components of its axis direction vector about the origin in the X, Y, and Z axes. A1, B1, and C1 are the components of the position vector of the end of the robot R1 in the Y, Z, and X axes respectively. In formula (8), For the moving pair, the first three columns are all 0, and the last three columns are the components of its axis direction vector in the X, Y, and Z axes. It is a revolute pair. The first three columns are the components of its axis direction vector in the X, Y, and Z axes. The last three columns are the components of the linear moment of its axis direction vector about the origin in the X, Y, and Z axes. A2, B2, and C2 are the components of the position vector of the end of the robot arm R2 in the Y, Z, and X axes respectively.

[0062] Step 3: Use the input selection method to obtain all reasonable input combinations for the dual-arm robot. The input selection method is as follows: when all active pairs are locked, the mechanism loses all degrees of freedom and cannot move. The drive input is reasonable; otherwise, it is unreasonable. Therefore, when selecting input for the dual-arm, one can select a kinematic pair in each branch and assume it is rigid. Then, analyze the constrained spiral system of the dual-arm robot at this time. If the maximum linear independence number of the constraint spiral system is 6, the mechanism loses all degrees of freedom and the input selection is reasonable. If the maximum linear independence number is less than 6, the mechanism does not lose all degrees of freedom, and uncontrollable degrees of freedom still exist, making the input selection unreasonable.

[0063] In the 2-RPPPS dual-arm robot, any combination of eight kinematic pairs is considered a reasonable input combination. All combinations that satisfy the input selection method and have the same number of kinematic pairs selected on arms R1 and R2 are considered reasonable input combinations. This yields 58 reasonable input combinations for the 2-RPPPS dual-arm robot, as shown in Table 1.

[0064] Table 1 Reasonable input groups

[0065]

[0066]

[0067] Step 4: According to the working conditions of the dual-arm robot, the motion constraint relationship of the dual-arm robot is determined as follows:

[0068]

[0069]

[0070] in For the coordinate system {O T} in the coordinate system {O}, is the pose of coordinate system {O1} in coordinate system {O}, For the coordinate system {O T1} in the coordinate system {O1}, For the coordinate system {O T}In the coordinate system {O T1}, is the position of coordinate system {O2} in coordinate system {O}, For the coordinate system {O T2} in the coordinate system {O2}, For the coordinate system {O T}In the coordinate system {O T2} in the pose.

[0071] In formula (9) and formula (10), and It is related to the installation method of the manipulators R1 and R2, which are all known. When the expected position of the grasped object is known, The position of the end of the manipulator R1 and R2 relative to the base can be obtained through the constraint relationship for:

[0072]

[0073]

[0074] After the specific configurations of the robotic arms R1 and R2 are known, the forward kinematics and inverse kinematics equations of the robotic arms R1 and R2 are obtained.

[0075] Step 5: Using load-bearing performance as the evaluation index, select the optimal input combination from all reasonable input combinations of the dual-arm robot obtained in step 3. The evaluation index is:

[0076]

[0077] Among them, n is the total number of samples uniformly selected on the working trajectory of the grasped object, S 2 is the sample variance, μ is the sample mean, Q is the total variance of a reasonable input combination, representing the sum of the variances of all angular accelerations of the input combination, a is the sample value, representing the angular acceleration of an input kinematic pair, and is calculated using Equation (12):

[0078]

[0079] where t m is the time from the m+1th sample point to the mth sample point, ω(i,j) and a(i,j) are the angular velocity and angular acceleration of the i-th kinematic pair of the j-th manipulator during this period, Px m 、Py m 、Pz m are the positions of the mth sample point expected to arrive, θ(i,j) is the i-th kinematic angle of the j-th robotic arm, and v is the assumed speed of the object being rotated, v = 0.1 m / s.

[0080] The smaller the total variance Q of each input combination, the smaller the speed fluctuation of the input scheme, and the better the motion performance of the dual-arm robot. The combination with the smallest Q value is selected as the optimal combination. Set a circular arc trajectory (unit: mm) in the plane Z = 100, with (0, 400) as the center and (3000, 400) as the starting point as the grasped object's motion trajectory. Maintain a fixed posture and rotate 30 degrees counterclockwise. The motion trajectory is evenly decomposed into 100 sample points. The a value and Q value of each reasonable input combination are calculated. The smaller the total variance Q of the input combination, the smaller the speed fluctuation of the input combination, and the better the motion performance of the dual-arm robot. All reasonable input combinations for the 2-RPPPS dual-arm robot are shown in Table 1. Among all reasonable input combinations, the combination with the smallest Q value is selected as the optimal input combination, as shown in Table 2 below.

[0081] Table 2 Optimal input combination

[0082]

[0083] Step 6: Use the kinematic pair in the optimal input combination obtained in step 5 as the input pair, and the remaining kinematic pairs in the dual-arm robot as passive pairs. Adjust the rotation angle of the input pair to achieve tight coordinated operation control of the dual-arm robot's two arms.

[0084] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention description and drawings under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

[0085] Any matters not described in the present invention are applicable to the prior art.

Claims

1. A dual-arm robot coordinated control method, characterized in that: The method is suitable for double-arm tight coordination operation, and the method comprises the following steps: Step 1: Tight coordination of dual arms requires that the dual-arm robot has a strict motion constraint relationship. The grasped object and the robot's dual arms form a complete closed-chain structure, forming a parallel mechanism; Definition: T } is the coordinate system of the center of mass of the grasped object, {O T1 }、{O T2 } are the tool coordinate systems of the manipulators R1 and R2, {O} is the base coordinate system of the dual-arm robot, and {O1} and {O2} are the base coordinate systems of the manipulators R1 and R2, respectively; Step 2: Kinematic modeling of the dual-arm robot based on the screw theory: Among them, $ 11 、$ 12 、$ 13 ……$ 1n is the kinematic rotation of each kinematic pair in the manipulator R1, and n is the number of kinematic pairs in the manipulator R1; 21 、$ 22 、$ 23 ……$ 2m is the kinematic rotation of each kinematic pair in the manipulator R2, m is the number of kinematic pairs in the manipulator R2; [L i M i N i P i Q i R i ] is the sports vice $ i The Plücker coordinate expression form, when the kinematic pair $ i When L is the moving pair, i 、M i 、N i Both are 0, P i , Q i 、R i Deputy Sports Representative i The components of the axis direction vector in the X, Y, and Z axes; when the kinematic pair i For a rotating pair, L i 、M i 、N i Deputy Sports Representative i The components of the axis direction vector in the X, Y, and Z axes, P i , Q i 、R i Deputy Sports Representative i The components of the linear moment of the axis direction vector about the origin in the X, Y, and Z axes; i Represents any kinematic pair in the robot arm R1 or the robot arm R2; Step 3: Use the input selection method to obtain all reasonable input combinations of the dual-arm robot; the input selection method is: when all active pairs are locked, the mechanism loses all degrees of freedom and cannot move, and the drive input is reasonable, otherwise it is unreasonable; therefore, when selecting the input for the dual arms, select a certain kinematic pair in each branch and assume that it is rigidified, and then analyze the constrained spiral system of the dual-arm robot at this time. If the maximum linear independent number of the constrained spiral system is 6 at this time, the dual-arm robot loses all degrees of freedom and the input selection is reasonable; if the maximum linear independent number is less than 6, the dual-arm robot cannot lose all degrees of freedom, and there are still uncontrollable degrees of freedom, and the input selection is unreasonable; arbitrarily select a number of kinematic pairs in the dual-arm robot as a combination, and all combinations that meet the input selection method and have the same number of kinematic pairs selected on the manipulators R1 and R2 are reasonable input combinations; Step 4: According to the working conditions of the dual-arm robot, the motion constraint relationship of the dual-arm robot is determined as follows: in For the coordinate system {O T } in the coordinate system {O}, is the pose of coordinate system {O1} in coordinate system {O}, For the coordinate system {O T1 } in the coordinate system {O1}, For the coordinate system {O T }In the coordinate system {O T1 }, is the position of coordinate system {O2} in coordinate system {O}, For the coordinate system {O T2 } in the coordinate system {O2}, For the coordinate system {O T }In the coordinate system {O T2 } in the pose; In formula (3) and formula (4), and It is related to the installation method of the manipulators R1 and R2, which are all known. When the expected position of the grasped object is known, When the constraint relationship is used, the position of the end of the manipulator R1 and R2 relative to the base is obtained. for: After the specific configurations of the manipulators R1 and R2 are known, the forward kinematics and inverse kinematics equations of the manipulators R1 and R2 are obtained; Step 5: Using load-bearing performance as the evaluation index, select the optimal input combination from all reasonable input combinations of the dual-arm robot obtained in step 3; the evaluation index is: Among them, n is the total number of samples uniformly selected on the working trajectory of the grasped object, S 2 is the sample variance, μ is the sample mean, Q is the total variance of a reasonable input combination, representing the sum of the variances of all angular accelerations of the input combination, and a is the sample value, representing the angular acceleration of an input kinematic pair, which is calculated by formula (6): where t m is the time from the m+1th sample point to the mth sample point, ω(i,j) and a(i,j) are the angular velocity and angular acceleration of the i-th kinematic pair of the j-th manipulator during this period, respectively. m 、Py m 、Pz m are the expected position of the mth sample point, θ(i,j) is the i-th kinematic angle of the j-th manipulator, and v is the assumed speed of the object being rotated, v = 0.1 m / s; The smaller the total variance Q of each input combination, the smaller the fluctuation of the speed of the input scheme, the better the motion performance of the dual-arm robot, and the combination with the smallest Q value is selected as the optimal input combination; Step 6: Use the kinematic pair in the optimal input combination obtained in step 5 as the input pair, and the remaining kinematic pairs in the dual-arm robot as passive pairs. Adjust the rotation angle of the input pair to achieve tight coordinated operation control of the dual-arm robot's two arms.

2. A dual-arm robot coordinated control method according to claim 1, characterized in that: The dual-arm robot is a 2-RPPPS dual-arm robot.

3. A dual-arm robot coordinated control method according to claim 1, characterized in that: In step 3, the reasonable input combination includes 8 kinematic pairs.

4. A dual-arm robot coordinated control method according to claim 1, characterized in that: In step 5, n=100.

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