Dexterous hand finger joint angle control method, device and system and medium

Abstract

The invention provides a dexterous hand finger joint angle control method, device and system and a medium, and relates to the technical field of dexterous hands. The joint angles of the fingers of the dexterous hand comprise the first joint angle and the second joint angle, the first joint angle and the second joint angle belong to active degrees of freedom, and the control method for the joint angles of the fingers of the dexterous hand comprises the steps that a control instruction for the fingers of the dexterous hand is obtained; according to the control instruction, the tracking control law of the first joint angle and the tracking control law of the second joint angle, the first joint angle and the second joint angle are controlled, the tracking control law of the first joint angle and the tracking control law of the second joint angle are determined based on a superspiral sliding mode control algorithm and a dynamic model of the finger. Through the tracking control law designed based on the super-spiral sliding mode control algorithm and the dynamic model, the stability and precision of dexterous hand finger joint angle control are improved.

Description

Technical Field

[0001] The present application relates to the technical field of dexterous hands, and in particular to a method, device, system and medium for controlling the angles of finger joints of dexterous hands. Background Art

[0002] With the development of robotics technology, dexterous hands are increasingly used in various complex manipulation tasks.

[0003] In the control of dexterous hands, how to accurately and smoothly control the angles of finger joints is crucial to achieve fine manipulation of dexterous hands. In related technologies, the angles of finger joints of dexterous hands are controlled based on dynamic principles, neural network models and / or sensors deployed on the finger joints.

[0004] However, the stability and accuracy of the angle control of the finger joints of dexterous hands need to be improved. Summary of the invention

[0005] The present application provides a method, device, system and medium for controlling the angle of finger joints of a dexterous hand, so as to solve the problem of low stability and low precision of the angle control of finger joints of a dexterous hand.

[0006] In a first aspect, the present application provides a method for controlling the joint angles of fingers of a dexterous hand, including: the joint angles of the fingers of the dexterous hand include a first joint angle and a second joint angle, the first joint angle and the second joint angle are active degrees of freedom, and the method for controlling the joint angles of the fingers of the dexterous hand includes: obtaining control instructions for the fingers; controlling the first joint angle and the second joint angle according to the control instructions, the tracking control law of the first joint angle and the tracking control law of the second joint angle; wherein the tracking control law of the first joint angle and the tracking control law of the second joint angle are determined based on a super-helical sliding mode control algorithm and a dynamic model of the finger.

[0007] In some embodiments, the process of generating the tracking control law of the first joint angle or the tracking control law of the second joint angle includes: constructing a dynamic model; determining the state space form of the target joint angle based on the dynamic model, the target joint angle being the first joint angle or the second joint angle; constructing a tracking error corresponding to the target joint angle; constructing a sliding surface corresponding to the target joint angle based on the tracking error; constructing the tracking control law of the target joint angle based on the sliding surface, the super-helical sliding mode control algorithm and the state space form.

[0008] In some embodiments, constructing a dynamic model includes: constructing the dynamic model according to the Lagrange equation and parameter information of the fingers of the dexterous hand, wherein the parameter information includes structural information and state quantity information;

[0009] The kinetic model is expressed as:

[0010]

[0011] in, represents the first joint angle, represents the first derivative of the first joint angle, represents the second-order derivative of the first joint angle, represents the second joint angle, represents the first derivative of the second joint angle, represents the second derivative of the second joint angle, represents the control torque at the first joint of the finger of the dexterous hand, represents the control torque at the second joint of the finger of the dexterous hand, and is a coefficient related to the parameter information.

[0012] In some embodiments, constructing a sliding surface corresponding to a target joint angle according to a tracking error includes: derivatizing the tracking error to obtain a first-order derivative of the tracking error; constructing the sliding surface according to the tracking error and the first-order derivative of the tracking error; when the target joint angle is the first joint angle, the tracking error is expressed as:

[0013]

[0014] The first-order derivative of the tracking error is expressed as:

[0015]

[0016] The sliding surface is expressed as:

[0017]

[0018] in, represents the first joint angle, represents the first derivative of the first joint angle, represents the desired angle of the first joint, represents the desired first derivative of the first joint angle, represents the coefficient used to adjust the error convergence speed, s represents the sliding surface, represents the tracking error, represents the first-order derivative of the tracking error.

[0019] In some embodiments, a tracking control law for the target joint angle is constructed based on a sliding surface, a super-helical sliding mode control algorithm and a state-space form, including: differentiating the sliding surface to obtain a first derivative of the sliding surface; transforming the first derivative according to the state-space form to obtain a second derivative; determining the third derivative of the sliding surface based on the super-helical sliding mode control algorithm; and constructing a tracking control law for the target joint angle based on the second derivative and the third derivative.

[0020] In some embodiments, when the target joint angle is the first joint angle, the tracking control law is expressed as:

[0021]

[0022] in, , represents the control torque at the first joint of the finger of the dexterous hand, represents the control torque at the second joint of the finger of the dexterous hand, , , is a coefficient related to the parameter information of the dexterous hand fingers, represents the coefficient used to adjust the error convergence speed, represents the first-order derivative of the tracking error, are variables in the state space form, represents the desired second derivative of the first joint angle, and represents the sliding mode control parameter, s represents the sliding mode surface, represents the result after the sliding surface is positively processed, Represents a symbolic function.

[0023] In the second aspect, the present application provides a device for controlling the finger joint angles of a dexterous hand, wherein the fingers of the dexterous hand include a first joint angle and a second joint angle, wherein the first joint angle and the second joint angle are active degrees of freedom, and the device for controlling the finger joint angles of a dexterous hand includes: an acquisition module for acquiring control instructions for the fingers; a control module for controlling the first joint angle and the second joint angle according to the control instructions, a tracking control law for the first joint angle and a tracking control law for the second joint angle; wherein the tracking control law for the first joint angle and the tracking control law for the second joint angle are determined based on a super-helical sliding mode control algorithm and a dynamic model of the finger.

[0024] In a third aspect, the present application provides a dexterous hand control system, comprising: a processor, disposed on the dexterous hand or separately from the dexterous hand, for implementing the dexterous hand finger joint angle control method as described in the first aspect of the present application; and a dexterous hand, for performing corresponding actions according to the control of the processor.

[0025] In a fourth aspect, the present application provides a computer-readable storage medium, in which computer program instructions are stored. When the computer program instructions are executed by a processor, the method for controlling the angles of finger joints of dexterous hands as described in the first aspect of the present application is implemented.

[0026] In a fifth aspect, the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the method for controlling the angles of finger joints of dexterous hands as described in the first aspect of the present application.

[0027] The present application provides a method, device, system and medium for controlling the angle of the finger joints of a dexterous hand. The tracking control law for the first joint angle and the tracking control law for the second joint angle are determined based on a super-helical sliding mode control algorithm and a dynamic model of the fingers of the dexterous hand. The super-helical sliding mode control algorithm is robust and can effectively suppress the chattering phenomenon in the traditional sliding mode control algorithm. The tracking control law determined based on the super-helical sliding mode control algorithm and the dynamic model of the fingers of the dexterous hand is used to improve the stability and accuracy of the angle control of the finger joints of the dexterous hand, so that the finger joints of the dexterous hand can achieve smoother and more accurate angle tracking, thereby improving the execution accuracy and adaptability of the fingers of the dexterous hand in fine operation tasks. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0029] Figure 1 This is an example diagram of the structure of the index finger in a dexterous hand;

[0030] Figure 2 A flow chart of a method for controlling the angles of finger joints of a dexterous hand provided in one embodiment of the present application;

[0031] Figure 3 A flowchart of a process for generating a tracking control law for a first joint angle or a tracking control law for a second joint angle provided in an embodiment of the present application;

[0032] Figure 4 A schematic diagram of the structure of a dexterous hand finger joint angle control device provided in an embodiment of the present application;

[0033] Figure 5 This is a structural block diagram of a dexterous hand control system provided in one embodiment of the present application. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0035] Unlike traditional end effectors, dexterous hands have the characteristics of multiple degrees of freedom and strong nonlinearity. Traditional control methods are easily affected by the nonlinearity of dexterous hand control, the coupling between finger joints, and external disturbances. They are insufficient in the ability to deal with the precise control and rapid response of finger joints, and the joint angle tracking error is large. Applying traditional sliding mode control algorithms (such as non-singular fast terminal sliding mode algorithms) to the angle control of dexterous hand finger joints can increase the robustness of the angle control of dexterous hand finger joints. However, the sign function of the traditional sliding mode control algorithm has a jitter problem, which will affect the stability of dexterous hand control and the smoothness of finger movements.

[0036] In order to improve the stability and accuracy of the angle control of the finger joints of a dexterous hand, the embodiments of the present application provide a method, device, system and medium for controlling the angle of the finger joints of a dexterous hand. In the method for controlling the angle of the finger joints of a dexterous hand, based on the super-helical sliding mode control algorithm and the dynamic model of the fingers of the dexterous hand, the tracking control law of the finger joints of the dexterous hand is designed, and the tracking control law of the finger joints of the dexterous hand is used to realize the angle tracking control of the finger joints of the dexterous hand. On the one hand, the super-helical sliding mode control algorithm is robust and can effectively suppress the chattering phenomenon in the traditional sliding mode control algorithm, improve the stability and accuracy of the angle control of the finger joints of the dexterous hand, so that the finger joints of the dexterous hand can achieve smoother and more accurate angle tracking, and also reduce the burden of the angle control of the finger joints of the dexterous hand on the control system of the dexterous hand; on the other hand, the super-helical sliding mode control algorithm avoids the singularity problem in the control law and is applicable to more control scenarios; on the other hand, the super-helical sliding mode control algorithm has low complexity and low computational cost, which improves the efficiency of the angle control of the finger joints of the dexterous hand and meets the requirements of high response speed and high control accuracy of the dexterous hand in complex operation scenarios.

[0037] Among them, the technical means adopted by the devices, equipment and media and the technical effects produced can refer to the technical means adopted and the technical effects produced by the above-mentioned scheme, and will not be repeated here.

[0038] Take the index finger in the dexterous hand as an example. Figure 1 This is an example diagram of the structure of the index finger in a dexterous hand. Figure 1As shown, the index finger includes two joints: a first joint 101 and a second joint 102. The first joint angle θ1 and the second joint angle θ2 are active degrees of freedom, and the third joint angle θ3 is a passive degree of freedom. The index finger also includes a finger root 103 and a finger tip 104. The first joint angle θ1 is the angle of the line between the first joint 101 and the finger root 104 relative to the first coordinate system (i.e. Figure 1 The X-axis (i.e. Figure 1 The second joint angle θ2 is the angle between the first joint 101 and the second joint 102 relative to the second coordinate system (ie Figure 1 The X-axis (i.e. Figure 1 The third joint angle θ3 is the angle between the line between the second joint 102 and the finger tip 103 relative to the third coordinate system (i.e. Figure 1 The X-axis in the X3Y3 coordinate system (i.e. Figure 1 The angle between the X3 axis and the line between the second joint 102 and the first joint 101 is parallel.

[0039] Among them, active degrees of freedom refer to the degrees of freedom that can be controlled by a drive device to perform independent movement, and passive degrees of freedom refer to the degrees of freedom that are not controlled by a drive device and change position and / or posture under the action of external forces or their own structure.

[0040] Next, Figure 1 Taking the finger structure shown as an example, the method for controlling the angles of finger joints of dexterous hands is introduced through specific embodiments and drawings related to the specific embodiments.

[0041] Figure 2 The process of the dexterous hand finger joint angle control method provided in the embodiment of the present application Figure 1 .like Figure 2 As shown, the method of the embodiment of the present application includes:

[0042] S201, obtaining control instructions for the fingers of the dexterous hand.

[0043] In this embodiment, a control instruction from a driving device of the dexterous hand (e.g., a processor located on the dexterous hand) may be obtained, and the control instruction may be used to instruct the first joint angle to change to a first desired value and the second joint angle to change to a second desired value. The first joint angle and the second joint angle may refer to the aforementioned Figure 1 The description will not be repeated here.

[0044] As an example, when performing a grasping task, based on the task data and sensor data, a first expected value and a second expected value can be analyzed to obtain the first expected value, and the first joint angle can be controlled to track the change to the first expected value, and the second joint angle can be controlled to track the change to the second expected value, so as to control the position change and / or posture change of the dexterous fingers, thereby achieving object grasping.

[0045] S202, controlling the first joint angle and the second joint angle according to the control instruction, the tracking control law of the first joint angle and the tracking control law of the second joint angle, wherein the tracking control law of the first joint angle and the tracking control law of the second joint angle are determined based on the super-helical sliding mode control algorithm and the dynamic model of the dexterous hand fingers.

[0046] In this embodiment, the control torque of the first joint angle and the control torque of the second joint angle can be determined according to the control instruction, the tracking control law of the first joint angle and the tracking control law of the second joint angle; the first joint angle is tracked and controlled according to the control torque of the first joint angle, so that the first joint angle changes to the first expected value according to a certain trajectory; the second joint angle is tracked and controlled according to the control torque of the second joint angle, so that the second joint angle changes to the second expected value according to a certain trajectory. The tracking control law determined based on the superhelical sliding mode control algorithm and the dynamic model of the dexterous hand fingers has both the advantages of the superhelical control algorithm and conforms to the dynamic model of the dexterous fingers, and can effectively improve the stability and accuracy of controlling the first joint angle and the second joint angle.

[0047] In the embodiment of the present application, the tracking control law of the first joint angle and the tracking control law of the second joint angle are determined based on the super-helical sliding mode control algorithm and the dynamic model of the dexterous hand fingers. The super-helical sliding mode control algorithm is robust and can effectively suppress the chattering phenomenon in the traditional sliding mode control algorithm. The tracking control law determined based on the super-helical sliding mode control algorithm and the dynamic model of the dexterous hand fingers is adopted to improve the stability and accuracy of the angle control of the dexterous hand finger joints, so that the dexterous hand finger joints can achieve smoother and more accurate angle tracking, thereby improving the execution accuracy and adaptability of the dexterous hand fingers in fine operation tasks.

[0048] It should be noted that the dexterous hand finger of the above embodiment can be a single finger of the dexterous hand or multiple fingers of the dexterous hand. For multiple fingers of the dexterous hand, each finger can include a first joint and a second joint, and the tracking control of the finger joint angle can be achieved according to the steps of the above embodiment.

[0049] Figure 3 A flowchart diagram of the generation process of the tracking control law of the first joint angle or the tracking control law of the second joint angle provided in the embodiment of the present application. Figure 3As shown, the generation process of the tracking control law of the first joint angle or the tracking control law of the second joint angle may include:

[0050] S301, construct a dynamic model of the fingers of a dexterous hand.

[0051] In this embodiment, the dynamic model of the dexterous hand fingers can be constructed by analyzing the motion characteristics and force relationship of the dexterous hand fingers. For example, the dynamic model of the dexterous hand fingers can be constructed by comprehensively considering the mass, inertia, force conditions, etc. of each component of the dexterous hand fingers.

[0052] In a possible implementation, S301 includes: constructing a dynamic model of the dexterous hand fingers according to the Lagrangian equation and the parameter information of the dexterous hand fingers, wherein the parameter information of the dexterous hand fingers includes the structural information of the dexterous hand fingers and the state quantity information of the dexterous hand fingers. Thus, the dynamic model of the dexterous hand fingers is constructed by using the Lagrangian equation that is more suitable for processing motion systems with multiple degrees of freedom, nonlinearity, coupling and other characteristics, while taking into account the structure and state quantity of the dexterous hand fingers, thereby effectively improving the accuracy of the dynamic model of the dexterous hand fingers.

[0053] Among them, the prerequisites for constructing the dynamic model of the dexterous hand fingers may include: 1. The dexterous hand fingers are ideal rigid structures, and the deformation of the dexterous hand fingers is not considered; 2. The friction between the various parts in the dexterous hand fingers is ignored; 3. It is assumed that each joint of the dexterous hand fingers is a rigid body with uniform density; 4. Considering that the angle at the fingertips of the dexterous hand fingers (i.e., θ3 in the aforementioned embodiment) is a passive degree of freedom, the first joint angle and the second joint angle are active degrees of freedom, and the dexterous hand fingers are simplified into a planar elbow-type robotic arm.

[0054] Optionally, according to the Lagrange equation and the parameter information of the dexterous hand fingers, the dynamic model of the dexterous hand fingers can be constructed and expressed as:

[0055] Formula (1)

[0056] in, represents the first joint angle, represents the first derivative of the first joint angle, represents the second-order derivative of the first joint angle, represents the second joint angle, represents the first derivative of the second joint angle, represents the second derivative of the second joint angle, represents the control torque at the first joint of the finger of the dexterous hand, represents the control torque at the second joint of the finger of the dexterous hand.

[0057] in, and is a coefficient related to the parameter information of dexterous fingers. It is an element in the inertia matrix in the Lagrange equation (representing the mass distribution of the fingers of the dexterous hand and the influence of this mass distribution on the angular acceleration of the joint angle); is the rate of change of the elements in the inertia matrix in the Lagrange equation with respect to the generalized coordinates of the fingers of the dexterous hand. It is the coefficient of the Coriolis term related to the Coriolis force and the centrifugal force, which is used to describe the nonlinear dynamic coupling effect caused by the change of the inertia matrix.

[0058] and The formula is as follows:

[0059] Formula (2)

[0060] in, represents the mass of the first finger segment (i.e. the segment between the first joint and the root of the finger), It represents the mass of the second finger segment (i.e. the finger segment between the first joint and the second joint);

[0061] Indicates the length of the first finger segment; represents the distance from the mass point of the first finger segment to the origin (the root of the finger), Indicates the distance from the mass point of the second finger segment to the origin (the base of the finger); represents the moment of inertia of the first finger segment about the first axis, the first axis passes through the center of mass of the first finger segment and points to the side (left side or right side) of the first finger segment; represents the moment of inertia of the second finger segment about the second axis, the second axis passes through the center of mass of the second finger segment and points to the side (left side or right side) of the second finger segment; represents the potential energy of the first finger segment, It can be seen that the above parameter information of the fingers of the dexterous hand is used in the process of constructing the dynamic model.

[0062] S302, determining the state space form of the target joint angle according to the dynamic model of the fingers of the dexterous hand, where the target joint angle is the first joint angle or the second joint angle.

[0063] In this embodiment, the dynamic model of the fingers of the dexterous hand can be transformed to obtain the state space form of the target joint angle, wherein the state space form of the target joint angle describes the relationship between the target joint angle and multiple parameters and multiple variables in the dynamic model.

[0064] In a possible implementation, the dynamic model of the fingers of the dexterous hand is converted into a matrix form; the matrix form is transformed and simplified to obtain the state space form of the target joint angle.

[0065] In this implementation, the state space form of the target joint angle can be obtained by the following process: when the dynamic model of the dexterous hand fingers is the above formula (1), the dynamic model of the dexterous hand fingers is converted into a matrix form and can be expressed as:

[0066] Formula (3)

[0067] Formula (3) can be converted to:

[0068] Formula (4)

[0069] Based on formula (4), the state space form of the target joint angle can be transformed into the state quantity Take the first joint angle as an example, and we can get:

[0070] Formula (5)

[0071] Based on formula (2), we know

[0072]

[0073] Taking Table 1 as an example, we can see , this value is very small for the control process of dexterous fingers and can be ignored.

[0074] Therefore, we can

[0075] Simplified .based on , simplifying formula (5), we can get:

[0076] Formula (6)

[0077] Thus, the state space form of the first joint angle can be obtained as formula (6). The solution process of the state space form of the second joint angle can refer to the above process and will not be repeated here.

[0078] S303, constructing a tracking error corresponding to the target joint angle.

[0079] In this embodiment, the tracking error corresponding to the target joint angle can be constructed based on the current value of the target joint angle and the expected value of the target joint angle. The tracking error corresponding to the target joint angle reflects the difference between the current value of the target joint angle and the expected value of the target joint angle.

[0080] Optionally, when the target joint angle is the first joint angle, the tracking error corresponding to the first joint angle is It is expressed as:

[0081] Formula (7)

[0082] in, represents the expectation of the first joint angle. That is, the tracking error corresponding to the first joint angle is determined to be the difference between the first joint angle and the expectation of the first joint angle.

[0083] In a possible implementation, when the target joint angle is the second joint angle, the tracking error corresponding to the second joint angle is It is expressed as:

[0084] Formula (8)

[0085] in, represents the expectation of the second joint angle. That is, the tracking error corresponding to the second joint angle is determined to be the difference between the second joint angle and the expectation of the second joint angle.

[0086] S304, constructing a sliding surface corresponding to the target joint angle according to the tracking error corresponding to the target joint angle.

[0087] In this embodiment, the tracking error corresponding to the target joint angle can be differentiated to obtain the first-order derivative of the tracking error; based on the tracking error of the target joint angle and the first-order derivative of the tracking error of the target joint angle, a sliding surface is constructed for the control law of the target joint angle.

[0088] Optionally, when the target joint angle is the first joint angle, according to formula (7), the first-order derivative of the tracking error corresponding to the first joint angle can be expressed as:

[0089] Formula (9)

[0090] The sliding surface corresponding to the first joint angle is expressed as:

[0091] Formula (10)

[0092] in, represents the first derivative of the first joint angle, represents the desired first derivative of the first joint angle, represents the coefficient used to adjust the error convergence speed, s represents the sliding surface, represents the tracking error, represents the first-order derivative of the tracking error. The goal of the sliding surface is to make s=0, which makes and Converge to 0, and realize the trajectory tracking of the first joint angle change to the expected value.

[0093] Among them, the construction process of the sliding surface corresponding to the second joint angle can refer to the construction process of the sliding surface corresponding to the first joint angle, and will not be repeated here.

[0094] S305, constructing a tracking control law of the target joint angle according to the sliding mode surface corresponding to the target joint angle, the super-helical sliding mode control algorithm and the state space form of the target joint angle.

[0095] In this embodiment, since the sliding surface corresponding to the target joint angle is related to the tracking error corresponding to the target joint angle, the tracking error corresponding to the target joint angle is related to the current value and expected value of the target joint angle, and the current value of the target joint angle can be represented by the state space form of the target joint angle, the sliding surface corresponding to the target joint angle can be transformed based on the state space form of the target joint angle; in order to make the sliding surface corresponding to the target joint angle tend to 0 and have strong robustness, a super-helical sliding mode control algorithm can be introduced to obtain the control formula of the sliding surface corresponding to the target joint angle; combined with the sliding surface after the transformation of the state space form of the target joint angle and the control formula of the sliding surface corresponding to the target joint angle, a tracking control law for the target joint angle can be constructed.

[0096] In one possible implementation, Figure 3 As shown, S305 includes:

[0097] S3051, deriving the sliding surface corresponding to the target joint angle to obtain the first derivative of the sliding surface corresponding to the target joint angle.

[0098] Optionally, when the target joint angle is the first joint angle, the sliding surface corresponding to the first joint angle is differentiated to obtain a first derivative of the sliding surface corresponding to the first joint angle, which is expressed as:

[0099] Formula (11)

[0100] Wherein, formula (11) is derived based on formula (9) and formula (10). represents the first-order derivative of the sliding surface; represents the first derivative of the tracking error; represents the second-order derivative of the tracking error, , and Reference may be made to the explanations of the aforementioned embodiments.

[0101] Among them, when the target joint angle is the second joint angle, the expression formula of the first derivative of the sliding surface corresponding to the second joint angle can refer to the expression formula of the first derivative of the sliding surface corresponding to the first joint angle, and will not be repeated here.

[0102] S3052, transforming the first derivative of the sliding surface corresponding to the target joint angle according to the state space form of the target joint angle to obtain the second derivative of the sliding surface corresponding to the target joint angle.

[0103] Optionally, when the target joint angle is the first joint angle, the first derivative of the sliding surface corresponding to the first joint angle is transformed according to the state space form of the first joint angle to obtain the second derivative of the sliding surface corresponding to the first joint angle, which is expressed as:

[0104] Formula (12)

[0105] Wherein, formula (12) is derived based on formula (11) and formula (6).

[0106] Among them, when the target joint angle is the second joint angle, the expression formula of the second derivative of the sliding surface corresponding to the second joint angle can refer to the expression formula of the second derivative of the sliding surface corresponding to the first joint angle, and will not be repeated here.

[0107] S3053, adding a super-helical sliding mode control term in the super-helical sliding mode control algorithm to the first derivative of the sliding mode surface corresponding to the target joint angle, to obtain a third derivative of the sliding mode surface corresponding to the target joint angle.

[0108] Among them, the expression of the control law in the super-helical sliding mode control algorithm is:

[0109] Formula (13)

[0110] in, and represents the sliding mode control parameters, It represents the result after the sliding surface is positively processed. The meaning of positive processing is: if the value corresponding to s is negative, then The corresponding value is -s, that is, it is adjusted to a value of equal size and opposite sign; if the corresponding value of s is a positive number or 0, then the corresponding value of |s| is s, which is the same as the value of s. and , the convergence speed and robustness of the finger joint angle tracking control process of the dexterous hand can be controlled. and It can be adjusted in the actual scene and fixed after adjustment. and The value of may be different. Represents a symbolic function.

[0111] Therefore, optionally, when the target joint angle is the first joint angle, the super-helical sliding mode control term in the super-helical sliding mode control algorithm is added to the first derivative of the sliding mode surface corresponding to the first joint angle to obtain the third derivative of the sliding mode surface corresponding to the first joint angle, which is expressed as:

[0112] Formula (14)

[0113] Among them, when the target joint angle is the second joint angle, the expression formula of the third derivative of the sliding surface corresponding to the second joint angle can refer to the expression formula of the third derivative of the sliding surface corresponding to the first joint angle, and will not be repeated here.

[0114] S3054: Construct a tracking control law for the target joint angle based on the second derivative and the third derivative.

[0115] Optionally, by combining formula (12) and formula (14), when the target joint angle is the first joint angle, the tracking control law is expressed as:

[0116] Formula (15)

[0117] in, , represents the control torque at the first joint, represents the control torque at the second joint, , , is the coefficient related to the parameter information of the dexterous hand fingers, represents the coefficient used to adjust the error convergence speed, represents the first-order derivative of the tracking error, is a variable in the state space form (see formula (6) for details), represents the desired second-order derivative of the target joint angle, that is, the desired second-order derivative of the first joint angle, and represents the sliding mode control parameters.

[0118] Among them, the tracking control law corresponding to the second joint angle can refer to the tracking control law corresponding to the first joint angle, which will not be repeated here.

[0119] In an embodiment of the present application, a process is provided for constructing a tracking control law corresponding to the angle of the finger joints of a dexterous hand by combining a superhelical sliding mode control algorithm and a dynamic model of the fingers of a dexterous hand. The tracking control law constructed in this way can effectively improve the stability and accuracy of the angle control of the finger joints of a dexterous hand, so that the finger joints of a dexterous hand can achieve smoother and more accurate angle tracking, thereby improving the execution accuracy and adaptability of the fingers of a dexterous hand in fine manipulation tasks.

[0120] The following is an embodiment of the device of the present application, which can be used to execute the embodiment of the method of the present application. For details not disclosed in the embodiment of the device of the present application, please refer to the embodiment of the method of the present application.

[0121] Figure 4 The schematic diagram of the structure of the finger joint angle control device for the dexterous hand provided in the embodiment of the present application is as follows: Figure 4 As shown, the dexterous hand finger joint angle control device 400 of the embodiment of the present application includes: an acquisition module 401 and a control module 402. Among them:

[0122] The acquisition module 401 is used to acquire control instructions for the fingers of the dexterous hand.

[0123] The control module 402 is used to control the first joint angle and the second joint angle according to the control instruction, the tracking control law of the first joint angle and the tracking control law of the second joint angle, wherein the tracking control law of the first joint angle and the tracking control law of the second joint angle are determined based on the super-helical sliding mode control algorithm and the dynamic model of the dexterous hand fingers.

[0124] In some embodiments, the process of generating the tracking control law of the first joint angle or the tracking control law of the second joint angle includes: constructing a dynamic model; determining the state space form of the target joint angle based on the dynamic model, the target joint angle being the first joint angle or the second joint angle; constructing a tracking error corresponding to the target joint angle; constructing a sliding surface corresponding to the target joint angle based on the tracking error; constructing the tracking control law of the target joint angle based on the sliding surface, the super-helical sliding mode control algorithm and the state space form.

[0125] In some embodiments, constructing a dynamic model includes: constructing a dynamic model according to the Lagrange equation and parameter information of the finger, wherein the parameter information includes structural information and state quantity information; the dynamic model is expressed as:

[0126]

[0127] in, represents the first joint angle, represents the first derivative of the first joint angle, represents the second-order derivative of the first joint angle, represents the second joint angle, represents the first derivative of the second joint angle, represents the second-order derivative of the second joint angle, represents the control torque at the first joint of the dexterous hand fingers, represents the control torque at the second joint of the dexterous hand finger, and is the coefficient related to the parameter information.

[0128] In some embodiments, constructing a sliding surface corresponding to the target joint angle according to the tracking error includes: derivatizing the tracking error to obtain a first-order derivative of the tracking error; constructing a sliding surface corresponding to the target joint angle according to the tracking error and the first-order derivative of the tracking error; when the target joint angle is the first joint angle, the tracking error is expressed as: ; The first-order derivative of the tracking error is expressed as: ; The sliding surface is expressed as: ;in, represents the first joint angle, represents the first derivative of the first joint angle, represents the expected value of the first joint angle, represents the desired first derivative of the first joint angle, represents the coefficient used to adjust the error convergence speed, s represents the sliding surface, represents the tracking error, Represents the first derivative of the tracking error.

[0129] In some embodiments, a tracking control law for the target joint angle is constructed based on a sliding surface, a super-helical sliding mode control algorithm and a state-space form, including: differentiating the sliding surface to obtain a first derivative of the sliding surface; transforming the first derivative according to the state-space form to obtain a second derivative; determining the third derivative of the sliding surface based on the super-helical sliding mode control algorithm; and constructing a tracking control law for the target joint angle based on the second derivative and the third derivative.

[0130] In some embodiments, when the target joint angle is the first joint angle, the tracking control law is expressed as:

[0131]

[0132] in, , represents the control torque at the first joint, represents the control torque at the second joint, , , is the coefficient related to the parameter information of the finger, represents the coefficient used to adjust the error convergence speed, represents the first-order derivative of the tracking error, are variables in state-space form, Represents the desired second derivative of the first joint angle. and represents the sliding mode control parameter, s represents the sliding surface, It represents the result after the sliding surface is positively processed. The meaning of positive processing is: if the value corresponding to s is negative, then The corresponding value is -s, that is, it is adjusted to a value of equal size and opposite sign; if the corresponding value of s is a positive number or 0, then the corresponding value of |s| is s, which is the same as the value of s. Represents a symbolic function.

[0133] The device of this embodiment can be used to execute the technical solution of any of the above-mentioned method embodiments. Its implementation principle and technical effects are similar and will not be repeated here.

[0134] Figure 5 This is a structural block diagram of a dexterous hand control system provided in one embodiment of the present application.

[0135] Reference Figure 5 The dexterous hand control system 500 includes a processor 501 and a dexterous hand 502. The processor 501 is disposed on the dexterous hand 502 or is separated from the dexterous hand 502, and is used to implement the dexterous hand finger joint angle control method provided in any of the above embodiments; the dexterous hand 502 is used to perform corresponding actions according to the control of the processor 501.

[0136] An embodiment of the present application also provides a dexterous hand finger, which can implement the dexterous hand finger joint angle control method provided in any of the above embodiments under the control of a processor.

[0137] The present application also provides a computer-readable storage medium, in which computer-executable instructions are stored. When a processor executes the computer-executable instructions, the above-mentioned method for controlling the angles of finger joints of dexterous hands is implemented.

[0138] The present application also provides a computer program product, including a computer program, which, when executed by a processor, implements the above-mentioned method for controlling the angles of finger joints of dexterous hands.

[0139] The computer-readable storage medium mentioned above may be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk. The readable storage medium may be any available medium that can be accessed by a general or special-purpose computer.

[0140] An exemplary readable storage medium is coupled to the processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (ASIC). Of course, the processor and the readable storage medium can also exist in the dexterous hand control system as discrete components.

[0141] Those skilled in the art can understand that all or part of the steps of implementing the above-mentioned method embodiments can be completed by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, the steps of the above-mentioned method embodiments are executed; and the aforementioned storage medium includes: ROM, RAM, disk or optical disk and other media that can store program codes.

[0142] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for controlling the angle of finger joints of a dexterous hand, characterized in that: The joint angles of the fingers of the dexterous hand include a first joint angle and a second joint angle, the first joint angle and the second joint angle belong to active degrees of freedom, and the dexterous hand finger joint angle control method includes: Obtaining control instructions for fingers of the dexterous hand; Controlling the first joint angle and the second joint angle according to the control instruction, the tracking control law of the first joint angle and the tracking control law of the second joint angle; Wherein, the tracking control law of the first joint angle and the tracking control law of the second joint angle are determined based on a super-helical sliding mode control algorithm and a dynamic model of the fingers of the dexterous hand.

2. The method for controlling the angle of finger joints of dexterous hands according to claim 1, characterized in that: The generation process of the tracking control law of the first joint angle or the tracking control law of the second joint angle includes: constructing the kinetic model; Determining a state space form of a target joint angle according to the dynamic model, wherein the target joint angle is the first joint angle or the second joint angle; Constructing a tracking error corresponding to the target joint angle; Constructing a sliding surface corresponding to the target joint angle according to the tracking error; A tracking control law of the target joint angle is constructed according to the sliding mode surface, the super-helical sliding mode control algorithm and the state space form.

3. The method for controlling the angle of finger joints of dexterous hands according to claim 2, characterized in that: The constructing of the kinetic model comprises: Constructing the dynamic model according to the Lagrange equation and parameter information of the fingers of the dexterous hand, wherein the parameter information includes structural information and state quantity information; The kinetic model is expressed as: in, represents the first joint angle, represents the first derivative of the first joint angle, represents the second-order derivative of the first joint angle, represents the second joint angle, represents the first derivative of the second joint angle, represents the second derivative of the second joint angle, represents the control torque at the first joint of the finger of the dexterous hand, represents the control torque at the second joint of the finger of the dexterous hand, and is a coefficient related to the parameter information.

4. The method for controlling the angle of finger joints of dexterous hands according to claim 2, characterized in that: The step of constructing a sliding surface corresponding to the target joint angle according to the tracking error includes: Deriving the tracking error to obtain a first-order derivative of the tracking error; constructing the sliding surface according to the tracking error and the first-order derivative of the tracking error; When the target joint angle is the first joint angle, the tracking error is expressed as: The first-order derivative of the tracking error is expressed as: The sliding surface is expressed as: in, represents the first joint angle, represents the first derivative of the first joint angle, represents the desired angle of the first joint, represents the desired first derivative of the first joint angle, represents the coefficient used to adjust the error convergence speed, s represents the sliding surface, represents the tracking error, represents the first-order derivative of the tracking error.

5. The method for controlling the angle of finger joints of dexterous hands according to claim 2, characterized in that: The step of constructing the tracking control law of the target joint angle according to the sliding mode surface, the super-helical sliding mode control algorithm and the state space form comprises: Deriving the sliding surface to obtain a first derivative of the sliding surface; transforming the first derivative according to the state space form to obtain a second derivative; Determining the third derivative of the sliding surface based on a super-helical sliding mode control algorithm; A tracking control law of the target joint angle is constructed according to the second derivative and the third derivative.

6. The method for controlling the angle of finger joints of dexterous hands according to claim 5, characterized in that: When the target joint angle is the first joint angle, the tracking control law is expressed as: in, , represents the control torque at the first joint of the finger of the dexterous hand, represents the control torque at the second joint of the finger of the dexterous hand, , , is a coefficient related to the parameter information of the dexterous hand fingers, represents the coefficient used to adjust the error convergence speed, represents the first-order derivative of the tracking error, are variables in the state space form, represents the desired second derivative of the first joint angle, and represents the sliding mode control parameter, s represents the sliding mode surface, represents the result after the sliding surface is positively processed, Represents a symbolic function.

7. A dexterous hand finger joint angle control device, characterized in that: The joint angles of the fingers of the dexterous hand include a first joint angle and a second joint angle, wherein the first joint angle and the second joint angle belong to active degrees of freedom, and the dexterous hand finger joint angle control device includes: An acquisition module, used for acquiring control instructions for the fingers of the dexterous hand; a control module, configured to control the first joint angle and the second joint angle according to the control instruction, a tracking control law of the first joint angle and a tracking control law of the second joint angle; Wherein, the tracking control law of the first joint angle and the tracking control law of the second joint angle are determined based on a super-helical sliding mode control algorithm and a dynamic model of the fingers of the dexterous hand.

8. A dexterous hand control system, characterized in that: include: A processor, arranged on the dexterous hand or separately arranged from the dexterous hand, for implementing the dexterous hand finger joint angle control method according to any one of claims 1 to 6; The dexterous hand is used to perform corresponding actions according to the control of the processor.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer program instructions, and when the computer program instructions are executed by a processor, the method for controlling the angles of finger joints of a dexterous hand as claimed in any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method for controlling the angles of finger joints of a dexterous hand as claimed in any one of claims 1 to 6 is implemented.

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