A method and system for precise pose control of a flexible wrist joint

Abstract

The present application belongs to the field of robot control, and particularly discloses a precise pose control method and system of a flexible wrist joint. The flexible wrist joint comprises a moving platform and a static platform, and the moving platform and the static platform are connected through two pairs of diagonally arranged flexible cables. Each pair of diagonally arranged flexible cables is controlled by a motor. When the pose is controlled, the real-time relative pose of the moving platform relative to the static platform is determined during the movement to the target pose; the correction target pose is determined according to the error between the target pose and the real-time relative pose; then the stretching and contracting amounts of the flexible cables in two characteristic movement directions are calculated according to the kinematic model of the flexible wrist joint; the two characteristic movements are ulnar deviation / radial deviation movement and flexion / extension movement; the motor stroke amount is determined according to the stretching and contracting amounts of the flexible cables, so as to realize the real-time control of the pose of the flexible wrist joint. The present application realizes the decomposition of the wrist joint movement space, and eliminates the uncertain pose error introduced by the elastic element through the basic kinematic model and the pose feedback.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of robot control, and more particularly, relates to a precise pose control method and system of a flexible wrist joint. BACKGROUND

[0002] Robots have been widely used in industrial manufacturing processes. Traditional industrial robots are usually composed of rigid parts. Although such rigid robots have simple structures, their precision and application range are greatly limited. With the expansion of the application field of mechanical arms and the change of demand, the development of flexible mechanical arms has gradually become a research hotspot. Flexible mechanical arms have a wide application prospect in many fields due to their good flexibility and adaptability.

[0003] A flexible mechanical arm can be combined by a plurality of flexible joints. The mechanical arm obtains flexibility through the joints. A tendon driving wrist joint with embedded passive elastic elements is an important implementation form of the flexible joint. However, the precise control of the flexible mechanical joint has always been a difficult problem.

[0004] At present, the control method of the existing flexible mechanical arm needs to be based on the establishment of a complex kinematic model and a dynamic model of the flexible arm, and it is difficult to achieve precise pose control. Therefore, there is an urgent need for a precise pose control method for a flexible wrist joint. SUMMARY

[0005] In view of the above defects or improvement needs of the prior art, the present application provides a precise pose control method and system of a flexible wrist joint, which aims to eliminate the uncertain pose error introduced by the elastic element in the flexible wrist joint and improve the pose control precision of the flexible wrist.

[0006] To achieve the above-mentioned purpose, according to one aspect of the present application, a precise pose control method of a flexible wrist joint is provided. The flexible wrist joint includes a moving platform and a static platform. The moving platform and the static platform are connected by two pairs of diagonally arranged tendons. Each pair of diagonally arranged tendons is controlled by one motor.

[0007] The pose control of the flexible wrist joint includes the following steps:

[0008] During the movement of the flexible wrist joint to the target pose, the real-time relative pose of the moving platform relative to the static platform is determined.

[0009] According to the error between the target pose and the real-time relative pose, the corrected target pose is determined.

[0010] Based on the corrected target pose, the extension and contraction amounts of the tendons in two characteristic motion directions are calculated according to the kinematic model of the flexible wrist joint. The two characteristic motions are ulnar / radial deviation motion and flexion / extension motion.

[0011] The motor stroke amount is determined according to the extension and contraction amount of the flexible tendon in two characteristic motion directions, so that the real-time control of the posture of the flexible wrist joint is realized.

[0012] As a further preferred, the calculation formula of the corrected target posture is as follows:

[0013]

[0014]

[0015]

[0016] Wherein, X, Y are the corrected pitch angle and yaw angle, i.e. the corrected target posture; γ0, β0 are the target pitch angle and yaw angle, i.e. the target posture; K pγ , K dγ are the proportional parameter and differential parameter of the pitch angle respectively; K pβ , K dβ are the proportional parameter and differential parameter of the yaw angle respectively; E γ , E γ are the error and error change of the pitch angle respectively; E β , E β are the error and error change of the yaw angle respectively; γ, β are the real-time actual pitch angle and yaw angle, i.e. the real-time relative posture; E γ_pre is the error value of the pitch angle in the last time; E β_pre is the error value of the yaw angle in the last time.

[0017] As a further preferred, when the extension and contraction amount of the flexible tendon in two characteristic motion directions is calculated according to the kinematic model of the flexible wrist joint, the calculation formula is as follows:

[0018]

[0019]

[0020] Wherein, ΔL Xi is the extension and contraction amount of the tendon in the radial / ulnar direction after the i-th correction, ΔL Yi is the extension and contraction amount of the tendon in the flexion / extension direction after the i-th correction; X i , Y i are the i-th corrected pitch angle and yaw angle respectively, γ i-1 , β i-1 are the i-1-th detected real-time pitch angle and yaw angle respectively; c x , c yrespectively are the distance from the fulcrum of the attitude adjustment of the moving platform to the wide edge and the long edge of the static platform; θ is the angle between the line connecting the wide edge of the moving platform and the wide edge of the static platform and the fulcrum of the attitude adjustment of the moving platform; ω is the angle between the line connecting the long edge of the moving platform and the long edge of the static platform and the fulcrum of the attitude adjustment of the moving platform.

[0021] As a further optimization, the IMU is installed on both the moving platform and the static platform, and the real-time relative attitude of the moving platform relative to the static platform is determined according to the data fed back by the IMU, including:

[0022] According to the real-time attitude of the moving platform and the static platform relative to the same reference coordinate system detected by the IMU, the rotation matrix of the moving platform relative to the static platform is determined, and then the roll angle, the yaw angle and the pitch angle of the moving platform relative to the static platform, i.e. the real-time relative attitude, are obtained.

[0023] As a further optimization, before the flexible wrist joint receives each instruction activity, the attitude of the instruction is judged, including the following steps:

[0024] First, the range of the target attitude of the instruction is judged: if the target attitude exceeds the predetermined motion range, the instruction is ignored; if the target attitude is within the predetermined motion range, the error between the target attitude and the real-time relative attitude is further evaluated;

[0025] When the error between the target attitude and the real-time relative attitude is evaluated, if the error exceeds the preset threshold, the corrected target attitude is further determined, and the attitude of the flexible wrist joint is adjusted accordingly; if the error does not exceed the preset threshold, the attitude of the flexible wrist joint is not adjusted.

[0026] As a further optimization, the motor stroke amount is determined according to the extension and contraction amount of the flexible cable in the two characteristic motion directions, including:

[0027] First, the absolute stroke of the motor is determined according to the extension and contraction amount of the flexible cable in the two characteristic motion directions, then the attitude change direction of the flexible wrist joint is determined according to the positive and negative nature of the extension and contraction amount of the flexible cable, and the absolute stroke of the motor in the two characteristic motion directions is combined according to the attitude change direction to obtain the motor stroke amount.

[0028] As a further optimization, the calculation method of the absolute stroke of the motor is:

[0029]

[0030]

[0031] wherein, S X , S Y are the absolute strokes of the motor caused by the changes of the pitch angle and the yaw angle respectively; ΔL X is the extension and contraction amount of the flexible cable in the ulnar deviation / radial deviation direction, and ΔLY is the flexible cable's extension / contraction in the flexion / extension direction; I is the reduction ratio of the harmonic reducer; P is the number of pulses per revolution of the encoder; H is the pulse coefficient of the motor controller; and R is the radius of the motor output end groove wheel.

[0032] As a further preferred, the absolute stroke of the motor in the combination of the two characteristic motion directions is obtained by the method of:

[0033] If ΔL X ≤ 0, ΔL Y ≤ 0, then If ΔL X ≤ 0, ΔL Y > 0, then

[0034] If ΔL X > 0, ΔL Y ≤ 0, then If ΔL X > 0, ΔL Y > 0, then

[0035] Wherein, M1 and M2 are the stroke amounts of the two motors respectively.

[0036] According to the second aspect of the present application, there is provided a precise pose control system of a flexible wrist joint, comprising a processor, which is used to execute the precise pose control method of the flexible wrist joint.

[0037] According to the third aspect of the present application, there is provided a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to realize the precise pose control method of the flexible wrist joint.

[0038] Overall, compared with the prior art, the above technical solutions conceived by the present application mainly have the following technical advantages:

[0039] 1. The present application proposes a precise pose control method based on the basic motion model of a flexible wrist joint combined with pose feedback, which realizes the decomposition of the wrist joint motion space, controls the pose based on the basic kinematic model of the flexible wrist joint, and continuously corrects the influence of the elastic element and the joint load on the joint pose by detecting the real-time pose of the joint, eliminates the error introduced thereby, and thus realizes the precise pose adjustment of the joint.

[0040] 2. The present application uses IMU to feed back the dynamic platform pose in real time, and continuously adjusts the input parameters by comparing the state quantity of the joint with the target pose, thereby effectively solving the problem of difficult model establishment and parameter adjustment in the traditional control method, and thus realizing the precise pose control of the flexible arm.

[0041] 3. Before each instruction is received by the flexible wrist joint, the present invention judges and filters the posture of the instruction, which can prevent the posture instruction from exceeding the range of motion of the flexible wrist joint, thereby avoiding damage to the joint mechanism; at the same time, through error evaluation, it can prevent the wrist joint from being unable to stabilize in a certain posture and constantly shaking.

[0042] 4. This invention has the advantages of high control precision, strong robustness and good adaptability, and can be widely used in prosthetics, robots, automated production lines and other fields. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the flexible wrist joint precision posture control system according to an embodiment of the present invention;

[0044] Figure 2 This is a schematic diagram of the stretching and contraction of the flexible cable during a change in the posture of the flexible wrist joint according to an embodiment of the present invention;

[0045] Figure 3 Figures (a) to (d) are schematic diagrams of the rotation direction of the motor under four standard characteristic movements (extension, flexion, ulnar deviation, and radial deviation) of the flexible wrist joint in the embodiments of the present invention.

[0046] Figure 4 This is a schematic diagram of the winding structure of a flexible wrist joint driven by a flexible cable according to an embodiment of the present invention;

[0047] Figure 5 This is a flowchart of a precise posture control method for a flexible wrist joint according to an embodiment of the present invention. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0049] The embodiments of the present invention are based on Figure 4 The flexible wrist joint shown is used as an example for illustration. The flexible wrist joint includes a moving platform and a stationary platform. The moving platform and the stationary platform are connected by two pairs of diagonally arranged flexible cables. Each pair of diagonally arranged flexible cables is controlled by a motor. For its specific structure, please refer to patent CN114633282A.

[0050] In addition, an IMU is needed to be installed on the moving platform and the static platform of the flexible wrist joint in advance, and the IMUs are calibrated in the same environment and in the same posture before installation. When the IMUs are installed, the axes of the two IMU coordinate systems are ensured to be parallel and in the same direction, and the x and y axes of the IMU coordinate systems are ensured to be parallel to the x and y axes of the static platform coordinate system, respectively, and the rotation of the moving platform around the x axis of the static platform coordinate system is equivalent to the movement in the ulnar deviation / radial deviation direction of the flexible wrist joint, and the rotation of the moving platform around the y axis of the static platform coordinate system is equivalent to the movement in the flexion / extension direction of the flexible wrist joint. When the two IMUs are installed, the x axes of the two IMUs are parallel to the wide sides of the corresponding platforms, and the y axes of the two IMUs are parallel to the long sides of the corresponding platforms. The driving motor on the lower side of one of the two IMUs is defined as the No. 1 motor, and the other driving motor is defined as the No. 2 motor.

[0051] The precise posture control process of the flexible wrist joint of the present application is shown in Figure 1 The host outputs a posture instruction to the wrist joint controller, and the instruction output by the host is the initial target posture of the flexible wrist joint, including the target pitch angle γ0 and the target yaw angle β0 of the moving platform relative to the static platform. The wrist joint controller adjusts the initial target posture according to the received instruction and the real-time posture of the wrist joint moving platform and the error change amount of the moving platform fed back by the IMU detection module, and then calculates the stroke amounts of the two coupled motors through the kinematic model of the wrist joint, so as to control the driving motors to operate.

[0052] Since the flexible wrist joint driven by the flexible cable has large flexibility, it is difficult to model the dynamics, the control model of the flexible joint is relatively complex, and the posture control of the wrist joint is not accurate. However, the precise posture control method of the flexible wrist joint driven by the flexible cable of the present application can compensate for the influence of the flexible cable driving and the embedded elastic element on the posture of the wrist joint by feeding back the real-time postures of the moving platform and the static platform of the flexible wrist joint and correcting the strokes of the two coupled motors, so as to realize precise posture control.

[0053] Specifically, the precise posture control method of the flexible wrist joint provided by the embodiment of the present application is shown in Figure 5 and includes the following steps:

[0054] S1, receiving the wrist joint target posture instruction of the host computer, and judging whether the target posture instruction is within a predetermined range:

[0055] If the target posture instruction is within the predetermined range, the subsequent operation is continued; if the target posture instruction exceeds the predetermined range, it is considered that the target posture instruction has an error, and the current instruction is ignored, and the wrist joint controller continues to receive the target posture instruction sent subsequently by the host computer.

[0056] S2, calculating the real-time relative posture of the wrist joint moving platform relative to the static platform, and judging whether the error between the current real-time relative posture and the target posture is within an error range:

[0057] The roll, yaw and pitch angles of the static platform are defined as α SP , β SP , γ SP , respectively. The roll, yaw and pitch angles of the moving platform are defined as α MP , β MP , γ MP , respectively. The roll, yaw and pitch angles of the moving platform relative to the static platform coordinate system are defined as α, β, γ, respectively.

[0058] The error and error change of the pitch angle are defined as E γ , E γ ' respectively.

[0059] The error and error change of the yaw angle are defined as E β , E β ' respectively.

[0060] The actual pitch and yaw angles of the moving platform relative to the static platform are defined as γ, β.

[0061] The error value of the last pitch angle is defined as E γ_pre .

[0062] The error value of the last yaw angle is defined as E β_pre .

[0063] The rotation matrix of the static platform relative to the reference coordinate system O is:

[0064]

[0065] The rotation matrix of the moving platform relative to the reference coordinate system O is:

[0066]

[0067] The rotation matrix of the moving platform relative to the static platform is:

[0068]

[0069]

[0070] When cosβ≠0, the real-time relative attitude of the flexible wrist joint moving platform relative to the static platform is:

[0071]

[0072] According to the real-time relative attitude of the moving platform relative to the static platform, the error between the real-time actual attitude and the target attitude is obtained as:

[0073]

[0074]

[0075] If the wrist joint posture error exceeds the error range, the subsequent operation is continued to be executed; if it is within the error range, it is considered that the wrist joint moving platform has reached the target posture, and the current posture control instruction is no longer executed, and the wrist joint controller continues to receive the target posture instruction sent by the host computer subsequently.

[0076] S3, the PD control model adjusts the input wrist joint target posture according to the error;

[0077] The final control input quantity (i.e. the corrected target posture) adjusted according to the posture error and the error change quantity is defined as X, Y respectively.

[0078] The proportional parameter and the differential parameter of the pitch angle are defined as K pγ ,K dγ ;

[0079] The proportional parameter and the differential parameter of the deflection angle are defined as K pβ ,K dβ ;

[0080] The output quantity of the PD control model after compensating for the posture deviation caused by the cable and the elastic element is:

[0081]

[0082] S4, the basic kinematics model of the wrist joint driven by the cable is used to determine the extension and contraction quantities of the cable in two characteristic motion directions.

[0083] In the basic kinematics model, the motion space of the flexible wrist joint is converted into a linear combination of two characteristic motions (ulnar / radial deflection, flexion / extension), and according to the physiological characteristics of the wrist joint, any posture of the wrist joint can be combined by the posture change of the moving platform in two characteristic motion directions. As shown in Figure 2 , the extension and contraction quantities of the cable are calculated in the ulnar / radial deflection characteristic direction and the flexion / extension characteristic direction of the wrist joint respectively, and the winding of the flexible wrist joint driven by the cable is as shown in Figure 3 .

[0084] The distance between the fulcrum of the moving platform posture adjustment and the long edge of the static platform is defined as c x ,c y ;

[0085] The angle between the line connecting the fulcrum of the moving platform posture adjustment and the wide edge of the moving platform and the wide edge of the static platform is defined as θ.

[0086] The angle between the fulcrum for adjusting the attitude of the moving platform and the line connecting the moving platform's long edge and the stationary platform's long edge is defined as ω;

[0087] The flexion / radial flexion and extension of the flexible cord are defined as ΔL. X ,ΔL Y ;

[0088] After the i-th correction, the flexural cable stretch / shortage in the ulnar / radial direction is:

[0089]

[0090] After the i-th correction, the amount of flexion / extension in the flexible cord stretching direction is:

[0091]

[0092] S5. Calculate the absolute stroke of the two coupled drive motors in the angular / radial deflection characteristic direction and the buckling / extension characteristic direction;

[0093] The reduction ratio of a harmonic reducer is defined as I;

[0094] The number of pulses per revolution of the encoder is defined as P;

[0095] The pulse coefficient of the motor controller is defined as H;

[0096] The radius of the grooved wheel at the motor output end is defined as R;

[0097] The absolute value of the motor stroke caused by the change in the pitch angle of the moving platform after the i-th correction:

[0098]

[0099] The absolute value of the motor stroke caused by the change in the deflection angle of the moving platform after the i-th correction:

[0100]

[0101] S6, the stroke of the combined coupled motor;

[0102] Combination Figure 4 As shown, and based on the sign of the flexible cable extension and the installation direction of the IMU, ΔL Xi <0 means the moving platform shifts to the left (in the scale direction); ΔL Xi >0 means the moving platform deflects to the right (radial direction); ΔL Yi <0 means the moving platform shifts forward (in the buckling direction); ΔL Yi >0 means the moving platform shifts backward (in the direction of extension).

[0103] The motor stroke coupled with the pose change in the two characteristic directions can obtain the final motion stroke of the driving motor (it is easy to understand that when the flexible cable extension amount is 0, the motor stroke is not affected):

[0104] If ΔL Xi <0, ΔL Yi <0, it means that the moving platform will move to the left front direction, then

[0105] If ΔL Xi <0, ΔL Yi >0, it means that the moving platform will move to the left rear direction, then

[0106] If ΔL Xi >0, ΔL Yi <0, it means that the moving platform will move to the right front direction, then

[0107] If ΔL Xi >0, ΔL Yi >0, it means that the moving platform will move to the right rear direction, then

[0108] The precise pose control method of the flexible cable driven flexible wrist joint of the application first judges the pose instruction sent by the host computer according to the actual pose of the flexible wrist joint moving platform and the pose range set in advance according to the mechanism parameters and the application scene through steps S1 and S2, and the instructions exceeding the preset pose range and in the error range are not executed, so as to avoid damage or continuous shaking of the flexible wrist joint mechanism; in order to eliminate the error caused by the flexible cable and the embedded elastic element to the wrist joint pose, step S3 adopts a PD control model to adjust the input wrist joint target pose; step S4 establishes a basic kinematics model of the flexible cable driven wrist joint according to the extension and contraction amount of the flexible cable in the two characteristic directions, and connects the pose change in the joint space with the mechanism parameters of the flexible wrist joint; step S5 calculates the absolute stroke of the two coupled driving motors in the characteristic direction of the ulnar deviation / radial deviation and the characteristic direction of the flexion / extension, and finally step S6 combines the final stroke amount M1 and M2 of the two coupled motors according to the positive and negative of the flexible cable extension and contraction amount in the two characteristic directions.

[0109] The application obtains the actual pose of the flexible cable driven flexible wrist joint moving platform embedded with the elastic element relative to the static platform, that is, the actual deflection angle β and the pitch angle γ of the flexible wrist joint moving platform, determines the pose tracking error E γ ,E β by comparing the actual value with the instruction value, and combines the error change amount E γ ', E βThe target posture X and Y are corrected according to the PD control model; the posture of the moving platform is transformed into the cable extension / extension ΔL in the two characteristic directions of ulnar / radial deviation and flexion / extension of the wrist joint through the basic kinematic model of the cable-driven wrist joint. Xi ,ΔL Yi Based on the cable stretching ΔL in the two characteristic directions Xi ,ΔL Yi By combining the parameters of the flexible wrist joint mechanism and the relevant parameters of the motor, the absolute stroke S of the two coupled drive motors in the ulnar / radial deviation characteristic direction and the flexion / extension characteristic direction is calculated. Xi ,S Yi Then, based on the sign of the elasticity of the flexible cable in the two characteristic directions, S... Xi ,S Yi By combining the two motors, the final stroke of the two coupled motors is obtained. The main controller continuously sends attitude commands to the wrist joint controller at a certain frequency. The wrist joint controller then continuously adjusts the attitude of the flexible wrist joint using the above method, thereby improving the attitude control accuracy of the wrist joint while ensuring the safety of the flexible wrist joint mechanism and the stability of the control effect.

[0110] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for accurate pose control of a flexible wrist joint, characterized by, The flexible wrist joint comprises a moving platform and a static platform, which are connected by two pairs of diagonally arranged flexible cables, each pair of diagonally arranged flexible cables being controlled by a motor; The posture of the flexible wrist joint is controlled, including the following steps: During the movement of the flexible wrist joint to the target posture, the real-time relative posture of the moving platform relative to the static platform is determined; According to the error between the target posture and the real-time relative posture, a corrected target posture is determined; The calculation formula is as follows: wherein, are the corrected pitch angle and yaw angle, respectively, i.e. the corrected target attitude; are the target pitch angle and yaw angle, respectively, i.e. the target attitude; are the proportional and derivative parameters for the pitch angle, respectively; are the proportional and derivative parameters for the yaw angle, respectively; are the error and error change of the pitch angle, respectively, are the error and error change of the yaw angle, respectively; are the real-time actual pitch angle and yaw angle, respectively, i.e. the real-time relative attitude; is the error value of the pitch angle at the last time; is the error value of the yaw angle at the last time; Based on the corrected target posture, the stretching and contracting amounts of the flexible cables in two characteristic movement directions are calculated according to the kinematic model of the flexible wrist joint; the two characteristic movements are ulnar deviation / radial deviation movement and flexion / extension movement; the calculation formula is as follows: wherein, is the first modified lateral displacement of the moving platform, i is the first modified lateral displacement of the moving platform, is the first modified lateral displacement of the moving platform, i is the first modified lateral displacement of the moving platform; are the first modified pitch angle and yaw angle of the moving platform, i are the first modified pitch angle and yaw angle of the moving platform, are the first modified pitch angle and yaw angle of the moving platform; i are the first modified pitch angle and yaw angle of the moving platform; are the first modified pitch angle and yaw angle of the moving platform; is the first modified pitch angle and yaw angle of the moving platform; is the first modified pitch angle and yaw angle of the moving platform; According to the stretching and contracting amounts of the flexible cables in the two characteristic movement directions, the motor stroke amount is determined to realize real-time control of the posture of the flexible wrist joint, including: First, the absolute stroke of the motor is determined according to the stretching and contracting amounts of the flexible cables in the two characteristic movement directions, and the calculation method is as follows: wherein, , are the absolute stroke of the motor caused by the pitch angle change and the yaw angle change, respectively; is the extension / contraction of the cable in the pitch / yaw direction, is the extension / contraction of the cable in the flexion / extension direction; is the reduction ratio of the harmonic reducer; is the number of pulses per revolution of the encoder; is the pulse coefficient of the motor controller; is the radius of the motor output end sheave; Then, the posture change direction of the flexible wrist joint is determined according to the positive and negative nature of the stretching and contracting amounts of the flexible cables; The absolute stroke of the motor in the two characteristic movement directions is combined according to the posture change direction to obtain the motor stroke amount: If , then ; if , then ; If , then ; if , then ; wherein, , are the stroke amounts of the two motors, respectively.

2. The method of precise pose control of a flexible wrist joint of claim 1, wherein, The IMU is installed on the moving platform and the static platform, and the real-time relative posture of the moving platform relative to the static platform is determined according to the data fed back by the IMU, including: According to the real-time postures of the moving platform and the static platform relative to the same reference coordinate system detected by the IMU, the rotation matrix of the moving platform relative to the static platform is determined, and then the roll angle, the yaw angle and the pitch angle of the moving platform relative to the static platform, i.e. the real-time relative posture, are obtained.

3. The method of precise pose control of a flexible wrist joint of claim 1, wherein, Before the flexible wrist joint receives each instruction activity, the posture of the instruction is judged, including the following steps: First, the range of the target posture of the instruction is judged: if the target posture exceeds the predetermined movement range, the instruction is ignored; if the target posture is within the predetermined movement range, the error between the target posture and the real-time relative posture is further evaluated; When the error between the target posture and the real-time relative posture is evaluated, if the error exceeds the preset threshold, the target posture is further corrected, and the posture of the flexible wrist joint is adjusted accordingly; if the error does not exceed the preset threshold, the posture of the flexible wrist joint is not adjusted.

4. A system for precise pose control of a flexible wrist joint, characterized by The computer program is executed by the processor to realize the accurate posture control method of the flexible wrist joint according to any one of claims 1-3.

5. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to realize the accurate posture control method of the flexible wrist joint according to any one of claims 1-3.

Images