CN118106945A - Robotic arm control method, device, robotic arm and readable storage medium - Google Patents

Abstract

The disclosure provides a mechanical arm control method, a device, a mechanical arm and a readable storage medium, wherein the method comprises the following steps: and determining the speed control quantity of the tail end of the mechanical arm according to the relative position relation between the current position of the tail end of the mechanical arm and the expected position, the expected speed and the singular position weight, and determining the speed control quantity of the joint of the mechanical arm and the position control quantity of the joint of the mechanical arm so as to control the movement of the mechanical arm. According to the method and the device, the mechanical arm can obtain a determined joint control parameter in each control period, gradual convergence is carried out in a plurality of control periods, calculation time consumption in a single control period is reduced, in addition, negative influences of singular positions of the mechanical arm on solving failure and the like caused by inverse solution process are reduced through the singular position weight, and reliability of an inverse solution calculation result is improved.

Description

Robotic arm control method, device, robotic arm and readable storage medium

Technical Field

The present disclosure relates to the technical field of robotic arms, and in particular to a robotic arm control method, a robotic arm, and a readable storage medium.

Background technique

Current robot arm control methods are mainly based on inverse solution of the input robot arm end control parameters to obtain the control parameters of the robot arm joints. Among them, the numerical inverse solution method is used as a commonly used inverse solution method because it has the advantage of not relying on the robot arm joint configuration. However, in the numerical inverse solution method of the robot arm, since multiple inverse solution calculations need to be performed in a single control cycle, the calculation is time-consuming, and when the robot arm is close to a singular configuration, a maximum value will be generated, resulting in failure of the inverse solution.

Summary of the invention

In view of this, the present disclosure provides a robot arm control method, device, robot arm and readable storage medium to at least solve the problems existing in the related art.

According to a first aspect of an embodiment of the present disclosure, a method for controlling a robot arm is provided, the method comprising:

Obtaining a desired position of the end of the robotic arm and a desired speed of the end of the robotic arm when the end of the robotic arm is at the desired position;

Determine the speed control amount of the end of the robotic arm according to the relative position relationship between the current position of the end of the robotic arm and the expected position, the expected speed and the singular position weight, wherein the singular position weight is related to the current joint configuration of the robotic arm;

Determining the speed control amount of the mechanical arm joint according to the speed control amount of the mechanical arm end;

According to the current joint position of the robot arm, the speed control amount of the robot arm joint determines the position control amount of the robot arm joint;

The movement of the robotic arm is controlled according to the speed control amount and the position control amount of the robotic arm joint.

In combination with any embodiment of the present disclosure, before determining the speed control amount of the end of the robotic arm according to the relative position relationship between the current position of the end of the robotic arm and the expected position, the expected speed and the singular position weight, the method further includes:

Determine the maximum spatial position that the robot can reach based on the maximum length of the robot and the preset boundary weight;

In response to the desired position exceeding the maximum spatial position, the desired position is corrected so that the desired position is within the maximum spatial position.

In combination with any embodiment of the present disclosure, before determining the speed control amount of the end of the robotic arm according to the relative position relationship between the current position of the end of the robotic arm and the expected position, the expected speed and the singular position weight, the method further includes:

Get the preset working space position of the robot arm;

In response to the desired position being outside the workspace position, the desired position is corrected so that the desired position is within the workspace position.

In combination with any embodiment of the present disclosure, the method further includes:

In response to the minimum singular value of the robot arm in the current joint configuration being less than or equal to the minimum singular value of the robot arm in the singular configuration, the singular position weight is zero;

In response to the minimum singular value of the robot arm in the current joint configuration being greater than the minimum singular value of the robot arm in the singular configuration and less than or equal to the maximum singular value of the robot arm in the singular configuration, the singular position weight is positively correlated with the singular value of the current joint configuration;

In response to the minimum singular value of the robot arm in the current joint configuration being greater than the maximum singular value of the robot arm in the singular configuration, the singular position weight is one;

The singular values are determined according to the Jacobian matrix of the joint configuration of the robot arm and the mapping relationship between the speed control amount of the end of the robot arm and the speed control amount of the joint of the robot arm.

In combination with any embodiment of the present disclosure, before determining the speed control amount of the end of the robotic arm according to the relative position relationship between the current position of the end of the robotic arm and the expected position, the expected speed and the singular position weight, the method further includes:

In response to the relative position relationship exceeding a preset position threshold, the relative position relationship is corrected so that the relative position relationship is within the preset position threshold.

In combination with any embodiment of the present disclosure, the determining the speed control amount of the robot arm joint according to the speed control amount of the robot arm end includes:

Based on the Jacobian matrix and the matrix damping value, determining the speed control amount of the robot arm joint according to the speed control amount of the end of the robot arm;

Wherein, in response to the minimum singular value of the robot arm in the current joint configuration being less than or equal to the minimum singular value of the robot arm in the singular configuration, the matrix damping value is negatively correlated with the singular value of the current joint configuration;

In response to the minimum singular value of the robot arm in the current joint configuration being greater than the minimum singular value of the robot arm in the singular configuration, the matrix damping value is zero;

The singular values are determined according to the joint configuration of the robot arm and the Jacobian matrix representing the mapping relationship between the speed control amount of the end of the robot arm and the speed control amount of the joint of the robot arm.

In combination with any embodiment of the present disclosure, before determining the position control amount of the mechanical arm joint according to the current joint position of the mechanical arm and the speed control amount of the mechanical arm joint, the method further includes:

Determine the limit speed of the joint of the robotic arm according to the Jacobian matrix, the degree of freedom of the robotic arm and at least one joint position of the robotic arm, wherein the Jacobian matrix represents the mapping relationship between the speed control amount of the end of the robotic arm and the speed control amount of the joint of the robotic arm;

According to the limit speed, the speed control amount of the robot arm joint is updated.

In combination with any embodiment of the present disclosure, the at least one joint position of the robotic arm includes an upper boundary position of the robotic arm joint, a lower boundary position of the robotic arm joint, and a midpoint position of the robotic arm joint.

In combination with any embodiment of the present disclosure, the speed control amount of the end of the robotic arm represents the moving speed of the end of the robotic arm in the current control cycle;

The speed control amount of the robot arm joint represents the moving speed of the robot arm joint in the current control cycle;

The position control amount of the robot arm joint represents the moving position of the robot arm joint in the current control cycle.

According to a second aspect of an embodiment of the present disclosure, a robot arm control device is provided, the device comprising:

A parameter acquisition module is used to: acquire the desired position of the end of the robot arm and the desired speed of the end of the robot arm when the end of the robot arm is at the desired position;

The terminal speed determination module is used to determine the speed control amount of the terminal of the manipulator according to the relative position relationship between the current position of the terminal of the manipulator and the expected position, the expected speed and the singular position weight, wherein the singular position weight is related to the current joint configuration of the manipulator;

A joint speed determination module, used to: determine the speed control amount of the mechanical arm joint according to the speed control amount of the mechanical arm end;

The joint position determination module is used to determine the position control amount of the robot arm joint according to the current joint position of the robot arm and the speed control amount of the robot arm joint;

The robot arm control module is used to control the movement of the robot arm according to the speed control amount and the position control amount of the robot arm joint.

In combination with any embodiment of the present disclosure, before determining the speed control amount of the end of the robotic arm according to the relative position relationship between the current position of the end of the robotic arm and the expected position, the expected speed and the singular position weight, the device further includes a first limit module, which is used to:

Determine the maximum spatial position that the robot can reach based on the maximum length of the robot and the preset boundary weight;

In response to the desired position exceeding the maximum spatial position, the desired position is corrected so that the desired position is within the maximum spatial position.

In combination with any embodiment of the present disclosure, before determining the speed control amount of the end of the robotic arm according to the relative position relationship between the current position of the end of the robotic arm and the expected position, the expected speed and the singular position weight, the device further includes a second limit module for:

Get the preset working space position of the robot arm;

In response to the desired position being outside the workspace position, the desired position is corrected so that the desired position is within the workspace position.

In combination with any embodiment of the present disclosure, the device further includes a weight determination module, which is used to:

In response to the minimum singular value of the robot arm in the current joint configuration being less than or equal to the minimum singular value of the robot arm in the singular configuration, the singular position weight is zero;

In response to the minimum singular value of the robot arm in the current joint configuration being greater than the minimum singular value of the robot arm in the singular configuration and less than or equal to the maximum singular value of the robot arm in the singular configuration, the singular position weight is positively correlated with the singular value of the current joint configuration;

In response to the minimum singular value of the robot arm in the current joint configuration being greater than the maximum singular value of the robot arm in the singular configuration, the singular position weight is one;

The singular values are determined according to the Jacobian matrix of the joint configuration of the robotic arm and the mapping relationship between the speed control amount of the end of the robotic arm and the speed control amount of the joint of the robotic arm.

In combination with any embodiment of the present disclosure, before determining the speed control amount of the end of the robotic arm according to the relative position relationship between the current position of the end of the robotic arm and the expected position, the expected speed and the singular position weight, the device also includes an error correction module for:

In response to the relative position relationship exceeding a preset position threshold, the relative position relationship is corrected so that the relative position relationship is within the preset position threshold.

In combination with any embodiment of the present disclosure, when the joint speed determination module determines the speed control amount of the mechanical arm joint according to the speed control amount of the mechanical arm end, it is specifically used to:

Based on the Jacobian matrix and the matrix damping value, determining the speed control amount of the robot arm joint according to the speed control amount of the end of the robot arm;

Wherein, in response to the minimum singular value of the robot arm in the current joint configuration being less than or equal to the minimum singular value of the robot arm in the singular configuration, the matrix damping value is negatively correlated with the singular value of the current joint configuration;

In response to the minimum singular value of the robot arm in the current joint configuration being greater than the minimum singular value of the robot arm in the singular configuration, the matrix damping value is zero;

The singular values are determined according to the joint configuration of the robot arm and the Jacobian matrix representing the mapping relationship between the speed control amount of the end of the robot arm and the speed control amount of the joint of the robot arm.

In combination with any embodiment of the present disclosure, before determining the position control amount of the mechanical arm joint according to the current joint position of the mechanical arm and the speed control amount of the mechanical arm joint, the device further includes a third limiting module, which is used to:

Determine the limit speed of the joint of the robotic arm according to the Jacobian matrix, the degree of freedom of the robotic arm and at least one joint position of the robotic arm, wherein the Jacobian matrix represents the mapping relationship between the speed control amount of the end of the robotic arm and the speed control amount of the joint of the robotic arm;

According to the limit speed, the speed control amount of the robot arm joint is updated.

In combination with any embodiment of the present disclosure, the at least one joint position of the robotic arm includes an upper boundary position of the robotic arm joint, a lower boundary position of the robotic arm joint, and a midpoint position of the robotic arm joint.

In combination with any embodiment of the present disclosure, the speed control amount of the end of the robotic arm represents the moving speed of the end of the robotic arm in the current control cycle;

The speed control amount of the robot arm joint represents the moving speed of the robot arm joint in the current control cycle;

The position control amount of the robot arm joint represents the moving position of the robot arm joint in the current control cycle.

According to a third aspect of an embodiment of the present disclosure, there is provided a robotic arm, comprising:

A memory, configured to store instructions executable by the processor;

The processor is configured to execute the executable instructions in the memory to implement the steps of the method described in any embodiment of the first aspect above.

According to a fourth aspect of the embodiments of the present disclosure, there is provided an electronic device, comprising a robotic arm, a memory for storing processor executable instructions, and a processor configured to execute the executable instructions in the memory to implement the steps of the method described in any one of the embodiments of the first aspect above. Optionally, the electronic device comprises a robot.

According to a fifth aspect of an embodiment of the present disclosure, a computer-readable storage medium is provided, on which a computer program is stored. When the program is executed by a processor, the steps of the method described in any embodiment of the first aspect are implemented.

The technical solution provided by the embodiments of the present disclosure may have the following beneficial effects:

The speed control amount of the end of the robotic arm is determined by the relative position relationship between the current position of the end of the robotic arm and the expected position, the expected speed and the weight of the singular position, and the relevant control parameters of the robotic arm joints are obtained by inverse solution. The robotic arm can obtain a certain joint control parameter in each control cycle, and gradually converge in multiple control cycles, reducing the calculation time in a single control cycle. In addition, the singular position weight is used to reduce the negative impact of the singular position of the robotic arm on the inverse solution process, such as the failure of the solution, and improve the reliability of the inverse solution calculation results.

It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

FIG1 is a schematic diagram of a mechanical arm according to an exemplary embodiment of the present disclosure;

FIG2 is a flow chart of a method for controlling a robotic arm according to an exemplary embodiment of the present disclosure;

FIG3 is a schematic diagram of a robot arm control device according to an exemplary embodiment of the present disclosure;

Fig. 4 is a block diagram of a robot arm device according to an exemplary embodiment of the present disclosure.

Detailed ways

Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. The singular forms "a", "the" and "the" used in this disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and/or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

It should be understood that although the terms first, second, third, etc. may be used in the present disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present disclosure, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

The current robot arm control method is mainly based on the inverse solution of the input robot arm end control parameters to obtain the control parameters of the robot arm joints. Exemplarily, Figure 1 is a schematic diagram of a robot arm shown in the present disclosure. Figure 1 takes a four-degree-of-freedom serial robot arm as an example. After obtaining the desired position and desired speed of the robot arm end, the numerical inverse solution method is used to calculate the joint angles and joint speeds required for the joints J1-J4 when the robot arm reaches the desired position at the desired speed, and then the joint control instructions are sent to the robot arm for execution. However, in the numerical inverse solution method of the robot arm, since multiple inverse solution calculations need to be performed within a single control cycle, the calculation is time-consuming, and when the robot arm is close to a singular position, a maximum value will be generated, resulting in the failure of the inverse solution.

In view of this, the present disclosure provides a robot arm control method to at least solve the problems existing in the related art.

FIG2 shows a flow chart of a method for controlling a robotic arm according to an exemplary embodiment of the present disclosure.

In step S101, the desired position of the end of the robot arm and the desired speed of the end of the robot arm when the end of the robot arm is at the desired position are obtained.

The expected position represents the target position of the end of the robot arm in the Cartesian space, and the expected speed represents the speed value of the end of the robot arm when it reaches the expected position. The expected position and expected speed can be determined by the user input to the control module of the robot arm, or can be determined according to the actual working requirements of the robot arm, and the present disclosure does not limit this.

In step S102, the speed control amount of the end of the robot arm is determined according to the relative position relationship between the current position of the end of the robot arm and the expected position, the expected speed and the singular position weight, wherein the singular position weight is related to the current joint configuration of the robot arm.

The current position of the end of the robotic arm represents the Cartesian spatial position of the end of the robotic arm at the current moment, and can be determined based on the position sensor of the robotic arm. The relative position relationship between the current position of the end of the robotic arm and the expected position represents the distance difference between the current position of the end of the robotic arm and the expected position. The singular position weight is used to reduce the jump interference caused by the singular position to the inverse solution process of the robotic arm, and can be determined based on the current joint configuration of the robotic arm. The speed control amount of the end of the robotic arm represents the required movement speed of the end of the robotic arm in the current control cycle in order for the end of the robotic arm to reach the expected position at the expected speed.

In one example, the speed control amount of the end of the robotic arm can be determined according to formula (1):

v _c = v _d + ρ*k _p *x _err (1)

In formula (1), _vc represents the velocity control amount of the end of the robot arm, _vd represents the desired velocity, and ρ represents the singular position weight.

_xerr represents the relative position relationship between the current position _xa of the end of the robot and the expected position _xd , as shown in formula (2):

x _err = x _d - x _a (2)

Specifically, x _a can be represented as the position of the end of the robot arm at the start of the current control cycle, and is updated in each control cycle, so that the speed control amount of the end of the robot arm is updated once in each control cycle, and finally reaches the desired position.

Optionally, _kp represents a preset robot position control gain, which is a gain coefficient of _xerr . In the process of the robot gradually moving to the desired position, _xerr gradually converges to 0 within multiple control cycles, and the convergence process can be accelerated or slowed down by _kp .

The singular position weight can be determined according to the current joint configuration of the robot. Since the inverse solution of the robot joint does not exist or is prone to jump extreme values when the robot is in a singular configuration, it will affect the inverse solution calculation result of the robot. Among them, the singular configuration includes boundary singular configuration and internal singular configuration. Since the boundary singular configuration only appears when the robot is at the working boundary, it can be avoided by constraining the working space of the robot. The internal singular configuration appears at the moment when the joint axes of the robot are collinear, resulting in reduced operability of the robot and reducing the movable area of the robot. Therefore, the singular position weight can be used to reduce the negative impact of the failure of the robot's singular position on the inverse solution process, such as the failure of solution.

In one example, the singular position weight can be determined by comparing the singular value of the robot arm in the current configuration with the singular value of the robot arm at the singular configuration moment, as shown in formula (3):

Among them, ∈ represents the minimum singular value of the robot in the current joint configuration, ∈ _min represents the minimum singular value of the current robot in all singular configurations, ∈ _max represents the maximum singular value of the current robot in all singular configurations, and the singular values are determined according to the Jacobian matrix representing the mapping relationship between the joint configuration of the robot and the speed control amount of the end of the robot and the speed control amount of the joint of the robot.

Specifically, when the minimum singular value of the current joint configuration of the robot is less than or equal to the minimum singular value of the robot in a singular configuration, that is, ∈≤∈ _min , it indicates that the current robot is in a singular configuration. The singular position weight can be controlled to be zero so that the robot moves in the desired speed and direction, thereby minimizing the influence of the singular configuration on the inverse solution process of the robot.

When the minimum singular value of the robot in the current joint configuration is greater than the minimum singular value of the robot in the singular configuration, and less than or equal to the maximum singular value of the robot in the singular configuration, that is, ∈ _min <∈≤∈ _max , it indicates that the current robot is approaching a singular configuration. The singular position weight can be controlled to be positively correlated with the singular value of the current joint configuration, for example, the singular position weight When the robot arm approaches the singular position, the weight of the singular position is continuously reduced to reduce the influence of the singular position on the inverse solution process of the robot arm.

When the minimum singular value of the current joint configuration of the robot arm is greater than the maximum singular value of the robot arm in the singular configuration, that is, ∈ _max <∈, it indicates that the current robot arm is moving away from the singular configuration. The terminal speed control amount of the robot arm in the current control cycle can be determined by controlling the singular position weight to 1 and jointly determining the expected speed and the relative position relationship between the current position and the expected position.

Preferably, in order to prevent the relative position relationship from being too different and causing a sudden change during the inverse solution process, the relative position relationship can be corrected when the relative position relationship exceeds a preset position threshold, so that the relative position relationship is within the preset position threshold, as described in formula (4):

In formula (4), x _err1 represents the relative position relationship after correction, and v _max represents the preset position threshold, which can be determined according to the maximum distance that the end of the robot arm can move at the fastest speed within a single control cycle.

In step S103, the speed control amount of the robot arm joint is determined according to the speed control amount of the robot arm end.

After obtaining the speed control amount of the end of the robot arm, the speed control amount of the robot arm joint in the current control cycle can be calculated through the mapping relationship between the robot arm joint speed and the end speed.

Exemplarily, the speed control amount of the robot arm joint can be determined by formula (5):

dq _c = J ⁺ *v _c (5)

In formula (5), dq _c represents the speed control amount of the robot arm joint, J represents the Jacobian matrix, J ⁺ represents the inverse solution operation form of the Jacobian matrix, and is determined according to the Jacobian matrix J and the matrix damping value. v _c is the speed control amount of the robot arm end obtained in the above steps.

The matrix damping value is used to scale the mapping relationship of J ⁺ to avoid the influence of the singular configuration on the inverse solution process of the robot arm.

Exemplarily, when the minimum singular value of the current joint configuration of the robot arm is less than or equal to the minimum singular value of the robot arm in the singular configuration, that is, ∈≤∈ _min , it indicates that the current robot arm is in the singular configuration, and the matrix damping value can be controlled to have a negative correlation with the singular value of the current joint configuration, as shown in formula (6):

In formula (6), Characterizing the matrix damping value, when the robot arm is in a singular position, the inverse solution process of the robot arm is prone to jump extreme values. In the process of reducing the minimum singular value of the robot arm in the singular position, by gradually amplifying the matrix damping value, the stability of the inverse solution process of the robot arm can be increased, and the influence of the singular position on the inverse solution process of the robot arm can be reduced.

When the minimum singular value of the robot in the current joint configuration is greater than the minimum singular value of the robot in the singular configuration, that is, ∈＞∈ _min , it indicates that the robot is not in a singular configuration, and the matrix damping value can be controlled to be 0, as shown in formula (7):

J ⁺ = J ^T *(J*J ^T ) ^-1 (7)

In formula (7), since the robot arm is not currently in a singular configuration, it is not necessary to scale the Jacobian matrix to obtain a Jacobian matrix suitable for the inverse solution process.

In step S104, the position control amount of the robot arm joint is determined according to the current joint position of the robot arm and the speed control amount of the robot arm joint.

The current joint position of the robotic arm can be determined by the position sensor of the robotic arm, which represents the position state of the robotic arm joint in the current control cycle. The position control amount of the robotic arm joint represents the required moving position of the robotic arm joint in the current control cycle in order to make the end of the robotic arm reach the expected position at the expected speed.

In one example, the position control amount of the robot arm joint can be determined by formula (8):

q _cmd = q _a + dq _c * δt (8)

In formula (8), q _cmd represents the position control amount of the robot arm joint, q _a represents the current joint position of the robot arm, dq _c represents the speed control amount of the robot arm joint, and σt represents the preset robot arm control period (for example, 0.5 ms or 0.8 ms).

Preferably, in order to ensure that the position control amount of the robot arm joint conforms to the actual joint position limit, the limit speed of the robot arm joint can be pre-determined before determining the position control amount of the robot arm joint and the speed control amount of the robot arm joint can be updated accordingly.

Specifically, the limit speed of the joint of the robotic arm can be determined according to the Jacobian matrix, the degree of freedom of the robotic arm and at least one joint position of the robotic arm, and the speed control amount of the joint of the robotic arm can be updated according to the limit speed, as shown in formula (9) and formula (10):

dq _cmd = dq _c + dq _b (10)

In formula (9), dq _b represents the limit speed of the robot arm joint, N(q) represents the null space matrix of the Jacobian matrix J, k _b represents the preset limit adjustment parameter of the robot arm joint, n represents the degree of freedom of the robot arm, q _max represents the upper boundary position of the robot arm joint, q _min represents the lower boundary position of the robot arm joint, and q _mid represents the midpoint position of the robot arm joint.

In formula (10), dq _cmd represents the updated speed control amount of the robot joint. By correcting the speed control amount of the robot joint by the limit speed, the position control amount of the robot joint can be made to conform to the actual joint position limit, ensuring that the joint movement mode of the robot conforms to the actual situation and avoiding the inverse solution jump problem that is easy to occur when the joint moves to the boundary position.

In step S105, the movement of the robot arm is controlled according to the speed control amount and the position control amount of the joint of the robot arm.

The speed control amount of the robot joint and the position control amount of the robot joint obtained in the above steps are sent to the joint controller of the robot arm, so that the robot arm can complete the corresponding movement action in the current control medium term. The above process is repeated continuously, so that in each control cycle, the robot arm is controlled according to the speed control amount and the position control amount of the robot joint, until the end of the robot arm finally reaches the desired position at the desired speed.

The method disclosed in the present disclosure determines the speed control amount of the end of the robotic arm in each control cycle through the relative position relationship between the current position of the end of the robotic arm and the expected position, the expected speed and the singular position weight, and obtains the relevant control parameters of the joints of the robotic arm in the current control cycle through inverse solution. The robotic arm can obtain a certain joint control parameter in each control cycle, and gradually converge in multiple control cycles, reducing the calculation time in a single control cycle. In addition, the singular position weight is used to reduce the negative impact of the singular position of the robotic arm on the inverse solution process, such as the failure of the solution, and improve the reliability of the inverse solution calculation results.

In an optional embodiment, before determining the speed control amount of the robot arm end based on the relative position relationship between the current position of the robot arm end and the expected position, the expected speed and the singular position weight, the expected position can also be pre-corrected to ensure the rationality of the expected position setting.

First, the maximum spatial position that the robot arm can reach can be determined based on the maximum length of the robot arm and the preset boundary weight. In response to the expected position exceeding the maximum spatial position, the expected position is corrected to make the expected position within the maximum spatial position.

The maximum length of the robotic arm represents the maximum length that the robotic arm can reach when each joint is fully extended, that is, when the robotic arm is "straightened". The boundary weight is the limitation coefficient of the maximum length of the robotic arm, so that the maximum length does not include the situation where the robotic arm is in a singular position. The maximum spatial position that the robotic arm can reach is the set of spatial positions composed of the maximum length that the robotic arm can reach excluding the singular position. In an example, the maximum spatial position represents a sphere composed of a set of position points at the farthest distance that the end of the robotic arm can reach.

In one example, the desired position of the end of the robotic arm may be determined by formula (11) for correction.

In formula (11), _xd1 represents the expected position after correction, _xd represents the expected position before correction, _Larm represents the maximum length of the robot arm, and _warm represents the preset boundary weight. When the expected position exceeds the maximum spatial position, that is, _xd > _Larm * _warm , the input expected position is corrected so that the expected position is within the maximum spatial position.

Afterwards, a preset working space position of the robot arm may be obtained, and in response to the expected position exceeding the working space position, the expected position may be corrected so that the expected position is within the working space position.

The working space position of the robot arm represents the set of positions that the end of the robot arm can reach in the actual working environment. In the actual working process, due to the interference of surrounding objects, the end of the robot arm usually cannot move smoothly within the maximum spatial position. The expected position can be further corrected by formula (12):

In formula (12), _xd2 represents the expected position after correction, _xd represents the expected position before correction, _Sboud (x, y, z) represents the preset working space position of the robot arm, and when the expected position exceeds the working space position, that is, _xd > _Sboud (x, y, z), the input expected position is corrected so that the expected position is within the working space position.

The method disclosed in the present invention pre-corrects the expected position to ensure the rationality of the setting of the expected position, so that the end of the robot arm always moves within the maximum spatial position and the working space position, thereby realizing the spatial limitation of the robot arm.

For the aforementioned method embodiments, for the sake of simplicity of description, they are all expressed as a series of action combinations, but those skilled in the art should know that the present disclosure is not limited by the described order of actions, because according to the present disclosure, certain steps can be performed in other orders or simultaneously.

Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily required by the present disclosure.

Corresponding to the aforementioned application function implementation method embodiment, the present disclosure also provides an application function implementation device and a corresponding terminal embodiment.

A block diagram of a robot arm control device shown in an exemplary embodiment of the present disclosure is shown in FIG3 , and the device includes:

The parameter acquisition module 301 is used to: acquire the desired position of the end of the robot arm and the desired speed of the end of the robot arm when the end of the robot arm is at the desired position;

The terminal speed determination module 302 is used to determine the speed control amount of the terminal of the manipulator according to the relative position relationship between the current position of the terminal of the manipulator and the expected position, the expected speed and the singular position weight, wherein the singular position weight is related to the current joint configuration of the manipulator;

The joint speed determination module 303 is used to determine the speed control amount of the mechanical arm joint according to the speed control amount of the mechanical arm end;

The joint position determination module 304 is used to determine the position control amount of the joint of the robotic arm according to the current joint position of the robotic arm and the speed control amount of the joint of the robotic arm;

The robot arm control module 305 is used to control the movement of the robot arm according to the speed control amount and the position control amount of the robot arm joint.

In combination with any embodiment of the present disclosure, before determining the speed control amount of the end of the robotic arm according to the relative position relationship between the current position of the end of the robotic arm and the expected position, the expected speed and the singular position weight, the device further includes a first limit module, which is used to:

Determine the maximum spatial position that the robot can reach based on the maximum length of the robot and the preset boundary weight;

In response to the desired position exceeding the maximum spatial position, the desired position is corrected so that the desired position is within the maximum spatial position.

In combination with any embodiment of the present disclosure, before determining the speed control amount of the end of the robotic arm according to the relative position relationship between the current position of the end of the robotic arm and the expected position, the expected speed and the singular position weight, the device further includes a second limit module for:

Get the preset working space position of the robot arm;

In response to the desired position being outside the workspace position, the desired position is corrected so that the desired position is within the workspace position.

In combination with any embodiment of the present disclosure, the device further includes a weight determination module, which is used to:

In response to the minimum singular value of the robot arm in the current joint configuration being less than or equal to the minimum singular value of the robot arm in the singular configuration, the singular position weight is zero;

In response to the minimum singular value of the robot arm in the current joint configuration being greater than the minimum singular value of the robot arm in the singular configuration and less than or equal to the maximum singular value of the robot arm in the singular configuration, the singular position weight is positively correlated with the singular value of the current joint configuration;

In response to the minimum singular value of the robot arm in the current joint configuration being greater than the maximum singular value of the robot arm in the singular configuration, the singular position weight is one;

The singular values are determined according to the Jacobian matrix of the joint configuration of the robotic arm and the mapping relationship between the speed control amount of the end of the robotic arm and the speed control amount of the joint of the robotic arm.

In combination with any embodiment of the present disclosure, before determining the speed control amount of the end of the robotic arm according to the relative position relationship between the current position of the end of the robotic arm and the expected position, the expected speed and the singular position weight, the device also includes an error correction module for:

In response to the relative position relationship exceeding a preset position threshold, the relative position relationship is corrected so that the relative position relationship is within the preset position threshold.

In combination with any embodiment of the present disclosure, when the joint speed determination module determines the speed control amount of the mechanical arm joint according to the speed control amount of the mechanical arm end, it is specifically used to:

Based on the Jacobian matrix and the matrix damping value, determining the speed control amount of the robot arm joint according to the speed control amount of the end of the robot arm;

Wherein, in response to the minimum singular value of the robot arm in the current joint configuration being less than or equal to the minimum singular value of the robot arm in the singular configuration, the matrix damping value is negatively correlated with the singular value of the current joint configuration;

In response to the minimum singular value of the robot arm in the current joint configuration being greater than the minimum singular value of the robot arm in the singular configuration, the matrix damping value is zero;

The singular values are determined according to the joint configuration of the robot arm and the Jacobian matrix representing the mapping relationship between the speed control amount of the end of the robot arm and the speed control amount of the joint of the robot arm.

In combination with any embodiment of the present disclosure, before determining the position control amount of the mechanical arm joint according to the current joint position of the mechanical arm and the speed control amount of the mechanical arm joint, the device further includes a third limiting module for:

Determine the limit speed of the joint of the robotic arm according to the Jacobian matrix, the degree of freedom of the robotic arm and at least one joint position of the robotic arm, wherein the Jacobian matrix represents the mapping relationship between the speed control amount of the end of the robotic arm and the speed control amount of the joint of the robotic arm;

According to the limit speed, the speed control amount of the robot arm joint is updated.

In combination with any embodiment of the present disclosure, the at least one joint position of the robotic arm includes an upper boundary position of the robotic arm joint, a lower boundary position of the robotic arm joint, and a midpoint position of the robotic arm joint.

In combination with any embodiment of the present disclosure, the speed control amount of the end of the robotic arm represents the moving speed of the end of the robotic arm in the current control cycle;

The speed control amount of the robot arm joint represents the moving speed of the robot arm joint in the current control cycle;

The position control amount of the robot arm joint represents the moving position of the robot arm joint in the current control cycle.

For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can refer to the partial description of the method embodiments. The device embodiments described above are only schematic, wherein the units described above as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the disclosed solution. A person of ordinary skill in the art can understand and implement it without paying any creative work.

The embodiments of the motion control device of this specification can be applied to a computer device of a robot arm, such as a server or a terminal device. The device embodiments can be implemented by software, or by hardware or a combination of software and hardware. Taking software implementation as an example, as a device in a logical sense, the corresponding computer program instructions in the non-volatile memory are read into the memory and run by the processor of the motion control in which it is located.

From the hardware level, as shown in Figure 4, there is a hardware structure diagram of the robotic arm where the motion control device of the embodiment of this specification is located. In addition to the processor 410, memory 430, network interface 420, and non-volatile memory 440 shown in Figure 4, the server or electronic device where the device is located in the embodiment may also include other hardware, usually according to the actual function of the computer device, which will not be described in detail.

Another embodiment of the present disclosure further provides a robotic arm. The robotic arm includes a memory for storing processor executable instructions; a processor configured to execute the executable instructions in the memory to implement the steps of the robotic arm control method provided in the present disclosure.

Another embodiment of the present disclosure further provides an electronic device. Optionally, the electronic device includes a robot, and the robot includes a robotic arm. The robot also includes a memory and a processor, the memory is used to store processor-executable instructions, and the processor is configured to execute the executable instructions in the memory to implement the steps of the robotic arm control method provided in the present disclosure.

Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The description and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.

It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims (21)

1. A robot arm control method, characterized in that the method comprises: Obtaining a desired position of the end of the robotic arm and a desired speed of the end of the robotic arm when the end of the robotic arm is at the desired position; Determine the speed control amount of the end of the robotic arm according to the relative position relationship between the current position of the end of the robotic arm and the expected position, the expected speed and the singular position weight, wherein the singular position weight is related to the current joint configuration of the robotic arm; Determining the speed control amount of the mechanical arm joint according to the speed control amount of the mechanical arm end; According to the current joint position of the robot arm, the speed control amount of the robot arm joint determines the position control amount of the robot arm joint; The movement of the robotic arm is controlled according to the speed control amount and the position control amount of the robotic arm joint. 2. The method according to claim 1, characterized in that before determining the speed control amount of the end of the manipulator according to the relative position relationship between the current position of the end of the manipulator and the expected position, the expected speed and the singular position weight, the method further comprises: Determine the maximum spatial position that the robot can reach based on the maximum length of the robot and the preset boundary weight; In response to the desired position exceeding the maximum spatial position, the desired position is corrected so that the desired position is within the maximum spatial position. 3. The method according to claim 1 or 2, characterized in that before determining the speed control amount of the end of the manipulator according to the relative position relationship between the current position of the end of the manipulator and the expected position, the expected speed and the singular position weight, the method further comprises: Get the preset working space position of the robot arm; In response to the desired position being outside the workspace position, the desired position is corrected so that the desired position is within the workspace position. 4. The method according to claim 1, characterized in that the method further comprises: In response to the minimum singular value of the robot arm in the current joint configuration being less than or equal to the minimum singular value of the robot arm in the singular configuration, the singular position weight is zero; In response to the minimum singular value of the robot arm in the current joint configuration being greater than the minimum singular value of the robot arm in the singular configuration and less than or equal to the maximum singular value of the robot arm in the singular configuration, the singular position weight is positively correlated with the singular value of the current joint configuration; In response to the minimum singular value of the robot arm in the current joint configuration being greater than the maximum singular value of the robot arm in the singular configuration, the singular position weight is one; The singular values are determined according to the Jacobian matrix of the joint configuration of the robotic arm and the mapping relationship between the speed control amount of the end of the robotic arm and the speed control amount of the joint of the robotic arm. 5. The method according to claim 1, characterized in that before determining the speed control amount of the end of the manipulator according to the relative position relationship between the current position of the end of the manipulator and the expected position, the expected speed and the singular position weight, the method further comprises: In response to the relative position relationship exceeding a preset position threshold, the relative position relationship is corrected so that the relative position relationship is within the preset position threshold. 6. The method according to claim 1, characterized in that the determining the speed control amount of the robot arm joint according to the speed control amount of the robot arm end comprises: Based on the Jacobian matrix and the matrix damping value, determining the speed control amount of the robot arm joint according to the speed control amount of the end of the robot arm; Wherein, in response to the minimum singular value of the robot arm in the current joint configuration being less than or equal to the minimum singular value of the robot arm in the singular configuration, the matrix damping value is negatively correlated with the singular value of the current joint configuration; In response to the minimum singular value of the robot arm in the current joint configuration being greater than the minimum singular value of the robot arm in the singular configuration, the matrix damping value is zero; The singular values are determined according to the joint configuration of the robot arm and the Jacobian matrix representing the mapping relationship between the speed control amount of the end of the robot arm and the speed control amount of the joint of the robot arm. 7. The method according to claim 1, characterized in that before determining the position control amount of the mechanical arm joint according to the current joint position of the mechanical arm and the speed control amount of the mechanical arm joint, the method further comprises: Determine the limit speed of the joint of the robotic arm according to the Jacobian matrix, the degree of freedom of the robotic arm and at least one joint position of the robotic arm, wherein the Jacobian matrix represents the mapping relationship between the speed control amount of the end of the robotic arm and the speed control amount of the joint of the robotic arm; According to the limit speed, the speed control amount of the robot arm joint is updated. 8. The method according to claim 1 is characterized in that the at least one joint position of the robotic arm includes an upper boundary position of the robotic arm joint, a lower boundary position of the robotic arm joint, and a midpoint position of the robotic arm joint. 9. The method according to claim 1, characterized in that the speed control amount of the end of the robot arm represents the moving speed of the end of the robot arm in the current control cycle; The speed control amount of the robot arm joint represents the moving speed of the robot arm joint in the current control cycle; The position control amount of the robot arm joint represents the moving position of the robot arm joint in the current control cycle. 10. A robot arm control device, characterized in that the device comprises: A parameter acquisition module is used to: acquire the desired position of the end of the robot arm and the desired speed of the end of the robot arm when the end of the robot arm is at the desired position; The terminal speed determination module is used to determine the speed control amount of the terminal of the manipulator according to the relative position relationship between the current position of the terminal of the manipulator and the expected position, the expected speed and the singular position weight, wherein the singular position weight is related to the current joint configuration of the manipulator; A joint speed determination module, used to: determine the speed control amount of the mechanical arm joint according to the speed control amount of the mechanical arm end; The joint position determination module is used to determine the position control amount of the robot arm joint according to the current joint position of the robot arm and the speed control amount of the robot arm joint; The robot arm control module is used to control the movement of the robot arm according to the speed control amount and the position control amount of the robot arm joint. 11. The device according to claim 10, characterized in that before determining the speed control amount of the end of the robot arm according to the relative position relationship between the current position of the end of the robot arm and the expected position, the expected speed and the singular position weight, the device further comprises a first limit module for: Determine the maximum spatial position that the robot can reach based on the maximum length of the robot and the preset boundary weight; In response to the desired position exceeding the maximum spatial position, the desired position is corrected so that the desired position is within the maximum spatial position. 12. The device according to claim 10 or 11, characterized in that before determining the speed control amount of the end of the robot arm according to the relative position relationship between the current position of the end of the robot arm and the expected position, the expected speed and the singular position weight, the device further comprises a second limit module for: Get the preset working space position of the robot arm; In response to the desired position being outside the workspace position, the desired position is corrected so that the desired position is within the workspace position. 13. The device according to claim 10, characterized in that the device further comprises a weight determination module, configured to: In response to the minimum singular value of the robot arm in the current joint configuration being less than or equal to the minimum singular value of the robot arm in the singular configuration, the singular position weight is zero; In response to the minimum singular value of the robot arm in the current joint configuration being greater than the minimum singular value of the robot arm in the singular configuration and less than or equal to the maximum singular value of the robot arm in the singular configuration, the singular position weight is positively correlated with the singular value of the current joint configuration; In response to the minimum singular value of the robot arm in the current joint configuration being greater than the maximum singular value of the robot arm in the singular configuration, the singular position weight is one; The singular values are determined according to the Jacobian matrix of the joint configuration of the robotic arm and the mapping relationship between the speed control amount of the end of the robotic arm and the speed control amount of the joint of the robotic arm. 14. The device according to claim 10, characterized in that before determining the speed control amount of the end of the manipulator according to the relative position relationship between the current position of the end of the manipulator and the expected position, the expected speed and the singular position weight, the device further comprises an error correction module for: In response to the relative position relationship exceeding a preset position threshold, the relative position relationship is corrected so that the relative position relationship is within the preset position threshold. 15. The device according to claim 10, characterized in that when the joint speed determination module determines the speed control amount of the mechanical arm joint according to the speed control amount of the mechanical arm end, it is specifically used to: Based on the Jacobian matrix and the matrix damping value, determining the speed control amount of the robot arm joint according to the speed control amount of the end of the robot arm; Wherein, in response to the minimum singular value of the robot arm in the current joint configuration being less than or equal to the minimum singular value of the robot arm in the singular configuration, the matrix damping value is negatively correlated with the singular value of the current joint configuration; In response to the minimum singular value of the robot arm in the current joint configuration being greater than the minimum singular value of the robot arm in the singular configuration, the matrix damping value is zero; The singular values are determined according to the joint configuration of the robot arm and the Jacobian matrix representing the mapping relationship between the speed control amount of the end of the robot arm and the speed control amount of the joint of the robot arm. 16. The device according to claim 10, characterized in that before determining the position control amount of the mechanical arm joint according to the current joint position of the mechanical arm and the speed control amount of the mechanical arm joint, the device further comprises a third limiting module for: Determine the limit speed of the joint of the robotic arm according to the Jacobian matrix, the degree of freedom of the robotic arm and at least one joint position of the robotic arm, wherein the Jacobian matrix represents the mapping relationship between the speed control amount of the end of the robotic arm and the speed control amount of the joint of the robotic arm; According to the limit speed, the speed control amount of the robot arm joint is updated. 17. The device according to claim 10, characterized in that the at least one joint position of the robotic arm includes an upper boundary position of the robotic arm joint, a lower boundary position of the robotic arm joint, and a midpoint position of the robotic arm joint. 18. The device according to claim 10, characterized in that the speed control amount of the end of the robot arm represents the moving speed of the end of the robot arm in the current control cycle; The speed control amount of the robot arm joint represents the moving speed of the robot arm joint in the current control cycle; The position control amount of the robot arm joint represents the moving position of the robot arm joint in the current control cycle. 19. A robotic arm, characterized in that the robotic arm comprises: A memory for storing processor executable instructions; A processor configured to execute the executable instructions in the memory to implement the steps of the method according to any one of claims 1 to 9. 20. An electronic device comprising a mechanical arm; A memory for storing processor executable instructions; A processor configured to execute the executable instructions in the memory to implement the steps of the method according to any one of claims 1 to 9. 21. A computer-readable storage medium having a computer program stored thereon, wherein when the program is executed by a processor, the steps of the method according to any one of claims 1 to 9 are implemented.