Robot joint constraint trajectory planning method, device, equipment and medium

Abstract

The present invention discloses a joint constraint trajectory planning method for a robot, comprising: determining a fifth parameter according to a joint torque constraint condition, and determining a sixth parameter according to a joint acceleration constraint condition; determining a path speed range of a preset path point according to a joint speed constraint condition, and determining a target constraint condition of a target function according to the path speed range, the fifth parameter, and the sixth parameter; optimizing the path speed of a target robot at a preset path point according to the target constraint condition and the target function, and determining a planned joint position corresponding to the target robot at the trajectory planning moment according to the optimal path speed. The present invention performs joint constraint trajectory planning on a target robot by adding joint torque constraints, joint acceleration constraints, and joint speed constraints, thereby avoiding problems of joint overload or low joint performance utilization in the target robot, and improving the accuracy of the robot's trajectory planning.

Description

Technical Field

[0001] The present invention relates to the field of computer technology, and in particular to a method, device, equipment and medium for planning joint constraint trajectories of a robot. Background Art

[0002] The robot motion control system is the core component of the entire robot operating system. It directly acts on the robot body and affects the operation process and results in the real physical environment. Trajectory planning is one of the most basic and key technologies in motion control.

[0003] Traditional trajectory planning methods usually only take static constraints into consideration but not joint constraints, which results in low accuracy of joint trajectory planning for robots. Summary of the invention

[0004] The present invention provides a method, device, equipment and medium for planning joint constraint trajectories of a robot, so as to solve the problem of low accuracy of joint trajectory planning of a robot in the prior art.

[0005] According to one aspect of the present invention, a robot joint constraint trajectory planning method is provided, comprising:

[0006] Determine a first nonlinear relationship between a joint position and a path position of the target robot, a second nonlinear relationship between a joint velocity and a path velocity, and a third linear relationship between a joint acceleration and the path velocity and the path acceleration;

[0007] Determine a fourth nonlinear relationship between the joint torque of the target robot and the path velocity and path acceleration according to the first nonlinear relationship, the second nonlinear relationship, the third nonlinear relationship and the robot dynamics equation;

[0008] determining a first parameter associated with the path speed and a second parameter associated with the path acceleration in the fourth non-linear relationship, and determining a third parameter associated with the path speed and a fourth parameter associated with the path acceleration in the third non-linear relationship;

[0009] Determine a fifth parameter in the first nonlinear constraint condition according to the first nonlinear constraint condition and the joint torque constraint condition of the fourth nonlinear relationship, and determine a sixth parameter in the second nonlinear constraint condition according to the second nonlinear constraint condition and the joint acceleration constraint condition of the third nonlinear relationship;

[0010] Determine a standard path position of the target robot corresponding to a preset path point, and determine a path speed range of the preset path point according to the standard path position and the joint speed constraint of the second nonlinear relationship, and determine a target constraint of an objective function according to the path speed range, the standard path position, the first parameter, the second parameter, the third parameter, the fourth parameter, the fifth parameter, and the sixth parameter;

[0011] The path speed of the target robot at the preset path point is optimized according to the target constraint condition and the objective function, the optimal path speed of the target robot at the preset path point is determined, and the planned joint position corresponding to the target robot at the trajectory planning moment is determined according to the optimal path speed, the standard path position, and the trajectory planning moment.

[0012] According to another aspect of the present invention, there is provided a joint constraint trajectory planning device for a robot, comprising:

[0013] A first nonlinear relationship determination module is used to determine a first nonlinear relationship between a joint position and a path position of a target robot, a second nonlinear relationship between a joint velocity and a path velocity, and a third nonlinear relationship between a joint acceleration and a path velocity and a path acceleration;

[0014] A second nonlinear relationship determination module is used to determine a fourth nonlinear relationship between the joint torque of the target robot and the path velocity and path acceleration according to the first nonlinear relationship, the second nonlinear relationship, the third nonlinear relationship and the robot dynamics equation;

[0015] a first parameter determination module, configured to determine a first parameter associated with the path speed and a second parameter associated with the path acceleration in the fourth nonlinear relationship, and to determine a third parameter associated with the path speed and a fourth parameter associated with the path acceleration in the third nonlinear relationship;

[0016] a second parameter determination module, configured to determine a fifth parameter in the first nonlinear constraint condition according to the first nonlinear constraint condition and the joint torque constraint condition of the fourth nonlinear relationship, and to determine a sixth parameter in the second nonlinear constraint condition according to the second nonlinear constraint condition and the joint acceleration constraint condition of the third nonlinear relationship;

[0017] a constraint condition determination module, used to determine a standard path position of the target robot corresponding to a preset path point, and determine a path speed range of the preset path point according to the standard path position and the joint speed constraint of the second nonlinear relationship, and determine a target constraint condition of an objective function according to the path speed range, the standard path position, the first parameter, the second parameter, the third parameter, the fourth parameter, the fifth parameter, and the sixth parameter;

[0018] The planning joint position determination module is used to optimize the path speed of the target robot at the preset path point according to the target constraint condition and the objective function, determine the optimal path speed of the target robot at the preset path point, and determine the planning joint position corresponding to the target robot at the trajectory planning moment according to the optimal path speed, the standard path position, and the trajectory planning moment.

[0019] According to another aspect of the present invention, there is provided an electronic device, the electronic device comprising:

[0020] at least one processor; and

[0021] a memory communicatively connected to the at least one processor; wherein,

[0022] The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the robot joint constraint trajectory planning method described in any embodiment of the present invention.

[0023] According to another aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the robot joint constraint trajectory planning method described in any embodiment of the present invention when executed.

[0024] The technical solution of the embodiment of the present invention performs joint constraint trajectory planning for the target robot by adding joint torque constraints, joint acceleration constraints and joint velocity constraints, thereby avoiding the problem of joint overload or low joint performance utilization of the target robot and improving the accuracy of the robot's joint trajectory planning.

[0025] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 A flowchart of a joint constraint trajectory planning method for a robot is provided for the first embodiment of the present invention;

[0028] Figure 2 A flowchart of a robot joint constraint trajectory planning method provided in Embodiment 2 of the present invention;

[0029] Figure 3 A schematic diagram of the structure of a joint constraint trajectory planning device for a robot provided in Embodiment 3 of the present invention;

[0030] Figure 4 It is a structural schematic diagram of an electronic device for implementing the robot joint constraint trajectory planning method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0032] It should be noted that the terms "first", "second", "third", "fourth", "fifth", "sixth", "candidate", and "target" in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0033] Traditional robot trajectory planning methods usually only consider the static constraints in Cartesian space, such as trajectory position, velocity, acceleration, jerk and other static constraints, but do not consider the joint constraints in the joint space. This may lead to problems such as joint overload or low joint performance utilization of the robot, which greatly affects the accuracy of the robot's joint constraint trajectory planning.

[0034] Embodiment 1

[0035] Figure 1 A flowchart of a robot joint constraint trajectory planning method is provided for the first embodiment of the present invention. This embodiment is applicable to the case of performing joint constraint trajectory planning for each machine joint included in the target robot. The method can be executed by a robot joint constraint trajectory planning device. The robot joint constraint trajectory planning device can be implemented in the form of hardware and / or software. The robot joint constraint trajectory planning device can be configured in the robot body or server. Figure 1 As shown, the method includes:

[0036] S101, determining a first nonlinear relationship between a joint position and a path position, a second nonlinear relationship between a joint velocity and a path velocity, and a third nonlinear relationship between a joint acceleration and a path velocity and a path acceleration of a target robot.

[0037] The target robot refers to a robot equipped with at least one machine joint, and the machine joint refers to a connection device between multiple machine links of the robot, which is used to enable relative movement between the multiple machine links, thereby providing the robot with the ability to move the machine links to any position and angle. The number of machine joints in the target robot can be set and adjusted according to the target robot operation scenario. For example, the target robot can include six machine joints, that is, a six-axis robot.

[0038] The joint position indicates the position of each machine joint of the target robot, which can be represented by an n-dimensional vector, where n is the number of machine joints included in the target robot. The joint velocity indicates the operating speed of the machine joint, and the joint acceleration indicates the operating acceleration of the machine joint.

[0039] The path position is a position information that can be calculated based on the running time of the target robot, that is, there is a functional relationship between the path position and the running time of the target robot: s = f(T), where s represents the path position and T represents the running time of the target robot. The path speed is the first-order derivative form of the path position, that is, there is a functional relationship between the path speed and the running time of the target robot: Where s represents the path position, T represents the running time of the target robot, Represents the path speed. The path acceleration is the second-order derivative form of the path position, that is, there is a functional relationship between the path acceleration and the running time of the target robot: Where s represents the path position, T represents the running time of the target robot, Represents the path acceleration.

[0040] In one embodiment, there is a nonlinear relationship between the joint position and the path position, that is, the joint position and the path position can form a nonlinear polynomial relationship. Optionally, the joint position and the path position form a cubic nonlinear polynomial relationship, that is, the first nonlinear relationship between the joint position and the path position can be expressed as follows: q = as 3 +bs 2 +cs+d, where q is the joint position, s is the path position, and a, b, c, and d are all polynomial coefficients.

[0041] There is also a nonlinear relationship between the joint velocity and the path velocity, that is, the joint velocity and the path velocity can also form a nonlinear polynomial equation relationship, that is, the second nonlinear relationship between the joint velocity and the path velocity can be expressed as follows: in, is the joint velocity, s is the path position, a, b, c, d are all polynomial coefficients, is the path speed.

[0042] There is also a nonlinear relationship between joint acceleration and path velocity and path acceleration, that is, a nonlinear polynomial equation relationship can be formed between joint acceleration and path velocity and path acceleration, that is, the third nonlinear relationship between joint acceleration and path velocity and path acceleration can be expressed as follows: in, is the joint acceleration, s is the path position, a, b, c, d are all polynomial coefficients, is the path speed, is the path acceleration.

[0043] Optionally, the first nonlinear relationship, the second nonlinear relationship and the third nonlinear relationship may be expressed as follows:

[0044]

[0045] Among them, s represents the path position, q represents the joint position, represents the path speed, represents the joint acceleration, represents the path acceleration, and q() is a cubic nonlinear polynomial.

[0046] By setting the first nonlinear relationship between the joint position and the path position to q=q(s), the second nonlinear relationship between the joint velocity and the path velocity is The third nonlinear relationship between joint acceleration and path velocity and path acceleration is This converts trajectory planning from a multidimensional problem into a two-dimensional problem, so that the subsequent constraints on joint information are converted into constraints on path information, simplifying the constraints.

[0047] S102 . Determine a fourth nonlinear relationship between the joint torque of the target robot and the path velocity and path acceleration according to the first nonlinear relationship, the second nonlinear relationship, the third nonlinear relationship, and the robot dynamics equation.

[0048] Among them, the robot dynamics equation is an equation that describes the relationship between the force and motion of the robot mechanism.

[0049] In one embodiment, according to the first nonlinear relationship, the "joint position parameters" in the robot dynamics equation are replaced by parameters; according to the second nonlinear relationship, the "joint velocity parameters" in the robot dynamics equation are replaced by parameters; according to the third nonlinear relationship, the "joint acceleration parameters" in the robot dynamics equation are replaced by parameters.

[0050] Optionally, S102 includes:

[0051] Substituting the first nonlinear relationship, the second nonlinear relationship, and the third nonlinear relationship into the robot dynamics equation, a fourth nonlinear relationship is obtained.

[0052] Among them, the robot dynamics equation is:

[0053]

[0054] Among them, A() represents the inertia matrix, B() represents the Coriolis force and centripetal force coefficient matrix, f() represents the gravity moment, and τ represents the joint moment.

[0055] Specifically, replace "q" in the robot dynamics equation with "q(s)". Replace with Replace with And according to the robot dynamics equation after parameter replacement, the fourth nonlinear relationship is obtained:

[0056]

[0057] By substituting the first nonlinear relationship, the second nonlinear relationship, and the third nonlinear relationship into the robot dynamics equation, the fourth nonlinear relationship is obtained, which realizes the conversion of joint torque into a form of path information representation and simplifies the subsequent constraint conditions for constraining the joint torque.

[0058] S103, determining a first parameter associated with the path speed and a second parameter associated with the path acceleration in the fourth nonlinear relationship, and determining a third parameter associated with the path speed and a fourth parameter associated with the path acceleration in the third nonlinear relationship.

[0059] In one embodiment, the parameter before “path speed” in the fourth nonlinear relationship is used as the first parameter associated with “path speed”, and the parameter before “path acceleration” in the fourth nonlinear relationship is used as the second parameter associated with “path acceleration”. The parameter before “path speed” in the third nonlinear relationship is used as the third parameter associated with “path speed”, and the parameter before “path acceleration” in the third nonlinear relationship is used as the fourth parameter associated with “path acceleration”.

[0060] Optionally, S103 includes:

[0061] The path speed in the fourth nonlinear relationship The previous parameter "A(q(s))q″(s)+q′(s) T B(q(s))q′(s)” as the first parameter, path acceleration The previous parameter "A(q(s))q'(s)" serves as the second parameter.

[0062] The path velocity in the third nonlinear relationship The previous parameter "q" (s) is used as the third parameter, path acceleration The previous parameter "q'(s)" serves as the fourth parameter.

[0063] By setting the first parameter to "A(q(s))q"(s)+q'(s) T The second parameter is "B(q(s))q′(s)", the second parameter is "A(q(s))q′(s)", the third parameter is "q″(s)", and the fourth parameter is "q′(s)", which lays the data foundation for the subsequent determination of the target constraint conditions of the objective function according to the first parameter, the second parameter, the third parameter and the fourth parameter.

[0064] S104. Determine the fifth parameter in the first nonlinear constraint condition according to the first nonlinear constraint condition and the joint torque constraint condition of the fourth nonlinear relationship, and determine the sixth parameter in the second nonlinear constraint condition according to the second nonlinear constraint condition and the joint acceleration constraint condition of the third nonlinear relationship.

[0065] The joint torque constraint condition consists of the minimum value of the joint torque and the maximum value of the joint torque. The joint acceleration constraint condition consists of the minimum value of the joint acceleration and the maximum value of the joint acceleration.

[0066] Optionally, in S104, “determining a fifth parameter in the first nonlinear constraint condition according to the first nonlinear constraint condition and the joint torque constraint condition of the fourth nonlinear relationship” includes:

[0067] The joint torque constraint condition is substituted into the first nonlinear constraint condition to determine the fifth parameter in the first nonlinear constraint condition.

[0068] Among them, the first nonlinear constraint is:

[0069] Fτ≤g1;

[0070] in, g1 represents the fifth parameter.

[0071] The joint torque constraints are:

[0072] τ min ≤τ≤τ max ;

[0073] Among them, τ represents the joint torque, τ min represents the minimum value of the joint torque, τ max Indicates the maximum value of the joint torque.

[0074] Specifically, the fifth parameter g1 is determined by the following equation group:

[0075]

[0076] It can be seen that the fifth parameter

[0077] By solving the fifth parameter This lays the data foundation for the subsequent determination of the target constraint conditions of the objective function based on the fifth parameter.

[0078] Optionally, in S104, “determining a sixth parameter in the second nonlinear constraint condition according to the second nonlinear constraint condition and the joint acceleration constraint condition of the third nonlinear relationship” includes:

[0079] The joint acceleration constraint condition is substituted into the second nonlinear constraint condition to determine the sixth parameter in the second nonlinear constraint condition.

[0080] The second nonlinear constraint is:

[0081]

[0082] in, g2 represents the sixth parameter,

[0083] The joint acceleration constraints are:

[0084]

[0085] in, represents the joint acceleration, represents the minimum value of joint acceleration, Indicates the maximum value of the joint acceleration.

[0086] Specifically, the sixth parameter g2 is determined by the following equation group:

[0087]

[0088] It can be seen that the sixth parameter

[0089] By solving the sixth parameter This lays the data foundation for the subsequent determination of the target constraint conditions of the objective function based on the sixth parameter.

[0090] S105. Determine the standard path position of the target robot corresponding to the preset path point, and determine the path speed range of the preset path point based on the joint speed constraint conditions of the standard path position and the second nonlinear relationship, and determine the target constraint conditions of the objective function based on the path speed range, the standard path position, the first parameter, the second parameter, the third parameter, the fourth parameter, the fifth parameter, and the sixth parameter.

[0091] The preset path points are discrete virtual path points generated by a preset discrete point generation algorithm, and the path positions of the preset path points are the standard path positions corresponding to the preset path points. The objective function is a function for solving the optimal path speed of the target robot at each preset path point when the target constraint condition is met.

[0092] In one embodiment, a joint speed relationship is generated according to the joint speed constraint and the second nonlinear relationship, and a path speed range of each preset path point is determined according to the joint speed relationship and the standard path position of each preset path point. Then, based on the path speed range, the standard path position, the first parameter, the second parameter, the third parameter, the fourth parameter, the fifth parameter, and the sixth parameter, a target constraint condition of the target function is formed.

[0093] Optionally, in S105, “determining a path speed range of a preset path point according to the standard path position and the joint speed constraint condition of the second nonlinear relationship” includes:

[0094] The joint velocity constraint condition and the second nonlinear relationship are combined to obtain the joint velocity relationship, and the standard path position is substituted into the joint velocity relationship to determine the path velocity range of the preset path point.

[0095] Among them, the joint velocity constraint is:

[0096]

[0097] in, represents the joint velocity, Indicates the minimum value of the joint velocity, Indicates the maximum value of the joint velocity.

[0098] Specifically, according to the second nonlinear relationship: The second nonlinear relationship Merge into joint velocity constraints In the equation, we get the joint velocity relationship:

[0099]

[0100] Move "q'(s)" in the joint velocity relationship to both sides of the inequality to obtain the path velocity Path speed range:

[0101]

[0102] By determining the path speed range of the preset path points, a data foundation is laid for subsequently determining the target constraint conditions according to the path speed range.

[0103] Optionally, in S105, “determining a target constraint condition of the target function according to the path speed range, the standard path position, the first parameter, the second parameter, the third parameter, the fourth parameter, the fifth parameter, and the sixth parameter” includes:

[0104] The lower limit parameter and the upper limit parameter of the target constraint condition are determined according to the fifth parameter and the sixth parameter, and the constraint matrix of the target constraint condition is determined according to the first parameter, the second parameter, the third parameter and the fourth parameter; the standard path position is substituted into the lower limit parameter, the upper limit parameter, the constraint matrix and the path speed range to determine the target constraint condition of the objective function.

[0105] Among them, the objective function is:

[0106]

[0107] in, is the parameter to be optimized of the objective function, and u represents the path acceleration x represents the path speed The square value of H represents a zero matrix, and z is [2Δs, -1]. Δs represents the distance value between the current preset path point and the adjacent preset path point. For example, assuming that the optimal path speed of the target robot at the i-th preset path point is calculated, the i-th preset path point is used as the current preset path point, and the i+1-th preset path point adjacent to the i-th preset path point is used as the adjacent preset path point, and then Δs is determined according to the distance value between the i-th preset path point and the i+1-th preset path point.

[0108] The target constraints are:

[0109]

[0110] Wherein, lbA represents the lower limit parameter, ubA represents the upper limit parameter, and both lbA and ubA are based on the fifth parameter and the sixth parameter. Represents the constraint matrix, which is composed of the first parameter, the second parameter, the third parameter and the fourth parameter.

[0111]

[0112] lb represents the parameter to be optimized of the objective function The lower limit value of ub represents the parameter to be optimized of the objective function. The upper limit value of . u_low and u_up represent the lower limit value and the upper limit value of the preset path acceleration range respectively.

[0113] Assuming that the optimal path speed of the target robot at the i-th preset path point is calculated, the standard path position s of the i-th preset path point is determined i , and according to the association relationship between the predetermined preset path points and the polynomial coefficients of the cubic nonlinear polynomial q(), determine the target polynomial coefficients associated with the i-th preset path point, and set the target polynomial coefficients to the polynomial coefficients of the cubic nonlinear polynomial q().

[0114] Set the standard path location s i Substitute into "f(q(s))" of lbA and ubA to calculate the specific values ​​of lbA and ubA. i Substitute into "q'(s)", "q"(s)", "A(q(s))q'(s)", and "A(q(s))q"(s)+q'(s) T In B(q(s))q′(s)”, we can calculate The specific value of the standard path location s i Substitute into the path speed In the path speed range, the lower limit value x_low of the path speed range and the upper limit value x_up of the path speed range are calculated, and then the target constraint condition of the objective function is determined.

[0115] By determining the lower limit parameter and upper limit parameter of the target constraint condition according to the fifth parameter and the sixth parameter, and determining the constraint matrix of the target constraint condition according to the first parameter, the second parameter, the third parameter and the fourth parameter; substituting the standard path position into the lower limit parameter, the upper limit parameter, the constraint matrix and the path speed range, the target constraint condition of the objective function is determined, which lays a data foundation for subsequently determining the optimal path speed of the target robot at each preset path point based on the objective function and the target constraint condition.

[0116] S106. Optimize the path speed of the target robot at the preset path points according to the target constraint conditions and the objective function, determine the optimal path speed of the target robot at the preset path points, and determine the planned joint positions corresponding to the target robot at the trajectory planning time according to the optimal path speed, the standard path position, and the trajectory planning time.

[0117] Among them, the trajectory planning moment indicates the moment when the joint position of the target robot needs to be predicted. In other words, when the corresponding joint positions of the target robot at all trajectory planning moments are predicted, it means that the joint constraint trajectory planning of the target robot is completed, and then the movement of the target robot can be controlled based on the joint constraint trajectory planning results.

[0118] In one embodiment, based on the objective function and the objective constraint of the objective function, a preset optimization calculation method is used to determine the optimal path speed of the target robot at each preset path point. Optionally, firstly, according to the order of each preset path point, the optimization solution is performed from front to back to determine the path acceleration and the square of the path velocity The optimal path speed and the optimal path acceleration that meet the target constraints are determined from the value range, and then the optimal solution is performed from back to front according to the order of the preset path points.

[0119] According to the standard path position of each preset path point, the interval distance value of the candidate interval path between each preset path point is determined, and then the candidate interval time required for the target robot to travel and complete each candidate interval path is determined according to the interval distance value and the optimal path speed of each preset path point. According to the candidate interval time, the candidate standard time period is determined, and according to the trajectory planning moment, the target standard time period is determined from the candidate standard time periods, and then according to the starting time of the target standard time period and the trajectory planning moment, the planned path speed corresponding to the target robot at the trajectory planning moment is determined, and according to the planned path speed, the planned path position corresponding to the target robot at the trajectory planning moment is determined, and finally according to the planned path position and the first nonlinear relationship, the planned joint position corresponding to the target robot at the trajectory planning moment is determined.

[0120] The present invention determines a first nonlinear relationship between a joint position and a path position of a target robot, a second nonlinear relationship between a joint speed and a path speed, and a third nonlinear relationship between a joint acceleration and the path speed and the path acceleration; determines a fourth nonlinear relationship between a joint torque and the path speed and the path acceleration of the target robot according to the first nonlinear relationship, the second nonlinear relationship, the third nonlinear relationship and the robot dynamics equation; determines a first parameter associated with the path speed and a second parameter associated with the path acceleration in the fourth nonlinear relationship, and determines a third parameter associated with the path speed and a fourth parameter associated with the path acceleration in the third nonlinear relationship; determines a fifth parameter in the first nonlinear constraint condition according to the first nonlinear constraint condition and the joint torque constraint condition of the fourth nonlinear relationship, and determines a sixth parameter in the second nonlinear constraint condition according to the second nonlinear constraint condition and the joint acceleration constraint condition of the third nonlinear relationship; determines the target robot's position relative to a preset path point. The method comprises the following steps: according to the standard path position corresponding to the target robot, and according to the joint speed constraint condition of the standard path position and the second nonlinear relationship, determining the path speed range of the preset path point, and determining the target constraint condition of the target function according to the path speed range, the standard path position, the first parameter, the second parameter, the third parameter, the fourth parameter, the fifth parameter, and the sixth parameter; optimizing the path speed of the target robot at the preset path point according to the target constraint condition and the target function, determining the optimal path speed of the target robot at the preset path point, and determining the planned joint position corresponding to the target robot at the trajectory planning moment according to the optimal path speed, the standard path position, and the trajectory planning moment; since the joint torque constraint condition, the joint acceleration constraint condition and the joint speed constraint condition are added to perform joint constraint trajectory planning for the target robot, the trajectory planning in Cartesian space can also meet the joint constraint, thereby avoiding the problem of joint overload or low joint performance utilization of the target robot, and improving the accuracy of the joint constraint trajectory planning of the robot.

[0121] Embodiment 2

[0122] Figure 2 This is a flow chart of a robot joint constraint trajectory planning method provided in the second embodiment of the present invention. This embodiment further optimizes and expands the "determining the planned joint position corresponding to the target robot at the trajectory planning moment according to the optimal path speed, standard path position, and trajectory planning moment" in the first embodiment above, and can be combined with the above-mentioned optional implementations. Figure 2 As shown, the method includes:

[0123] S201. Determine the interval distance value of the candidate interval paths between the preset path points according to the standard path position of each preset path point, and determine the candidate interval time required for the target robot to complete each candidate interval path according to the interval distance value and the optimal path speed of each preset path point.

[0124] In one embodiment, the interval distance value of the candidate interval path between adjacent preset path points is calculated according to the standard path positions of adjacent preset path points. That is, the interval distance value of the candidate interval path between each preset path point is determined according to the following formula: Δs i =s i+1 -s i , where i≥1,s i+1 and i Preset waypoints for adjacent ones.

[0125] The candidate interval time required for the target robot to travel to complete the candidate interval path is determined according to the speed average of the optimal path speeds of adjacent preset path points and the interval distance value of the candidate interval path between adjacent preset path points.

[0126] Optionally, the candidate interval time is determined by the following formula: Right now in, represents the optimal path speed of the i-th preset path point, Indicates the optimal path speed of the i+1th preset path point, Δs i Indicates the interval distance value of the candidate interval path between the i-th preset path point and the i+1-th preset path point, Δt i Indicates the candidate interval time required for the target robot to complete the candidate interval path.

[0127] S202, superimposing the candidate interval times to determine the candidate standard time periods for the target robot to travel to each candidate interval path, and determining the target standard time period to which the trajectory planning moment belongs from the candidate standard time periods.

[0128] In one embodiment, starting from the first candidate interval time, each candidate interval time is superimposed to determine the candidate standard time period for the target robot to travel to each candidate interval path, and the candidate standard time period at the time of trajectory planning is used as the target standard time period.

[0129] Exemplarily, it is assumed that the candidate interval path between the first preset path point and the second preset path point is taken as the first candidate interval path, the candidate interval path between the second preset path point and the third preset path point is taken as the second candidate interval path, ..., and the candidate interval path between the i-th preset path point and the i+1-th preset path point is taken as the i-th candidate interval path.

[0130] Assume that the candidate interval time required for the target robot to complete the first candidate interval path is Δt1, the candidate interval time required to complete the second candidate interval path is Δt2, ..., the candidate interval time required to complete the i-th candidate interval path is Δt i .

[0131] The candidate standard time period for the target robot to travel to the first candidate interval path is 0~Δt1, the candidate standard time period for traveling to the second candidate interval path is Δt1~(Δt1+Δt2), the candidate standard time period for traveling to the third candidate interval path is (Δt1+Δt2)~(Δt1+Δt2+Δt3), ..., the candidate standard time period for completing the i-th candidate interval path is

[0132] Assuming that the trajectory planning time is current_time, which belongs to the candidate standard time period (Δt1+Δt2)~(Δt1+Δt2+Δt3), (Δt1+Δt2)~(Δt1+Δt2+Δt3) is taken as the target standard time period.

[0133] S203: Determine a target interval time corresponding to a target standard time period from the candidate interval times, and determine a target interval path corresponding to the target standard time period from the candidate interval paths.

[0134] In one embodiment, the target interval time is determined according to the difference between the end time and the start time of the target standard time period. For example, assuming that the target standard time period is (Δt1+Δt2) to (Δt1+Δt2+Δt3), the difference Δt3 between the end time (Δt1+Δt2+Δt3) and the start time (Δt1+Δt2) is used as the target interval time.

[0135] According to the association between the candidate interval time and the candidate interval path, the target interval path associated with the target interval time is determined from the candidate interval path. For example, the candidate interval time required for the target robot to complete the first candidate interval path is Δt1, the candidate interval time required to complete the second candidate interval path is Δt2, ..., the candidate interval time required to complete the i-th candidate interval path is Δt i , assuming that the target interval time is Δt3, the target interval path associated with it is the third candidate interval path.

[0136] S204, determining the planned joint positions corresponding to the target robot at the trajectory planning moment according to the target interval time, the target interval path, the target standard time period and the trajectory planning moment.

[0137] The interval distance value of the candidate interval path between each preset path point is determined according to the standard path position of each preset path point, and the candidate interval time required for the target robot to complete each candidate interval path is determined according to the interval distance value and the optimal path speed of each preset path point; the candidate interval times are superimposed to determine the candidate standard time period for the target robot to travel to each candidate interval path, and the target standard time period to which the trajectory planning moment belongs is determined from the candidate standard time period; the target interval time corresponding to the target standard time period is determined from the candidate interval time, and the target interval path corresponding to the target standard time period is determined from the candidate interval path; the planned joint position corresponding to the target robot at the trajectory planning moment is determined according to the target interval time, the target interval path, the target standard time period and the trajectory planning moment, so as to achieve the effect of joint constraint trajectory planning for the target robot.

[0138] Optionally, S204 includes the following steps A, B and C:

[0139] A. Determine the starting optimal path speed of the starting path point in the target interval path and the ending optimal path speed of the ending path point, and determine the average path acceleration of the target interval path based on the starting optimal path speed, the ending optimal path speed and the target interval time.

[0140] In one embodiment, a speed difference between a starting optimal path speed and a terminating optimal path speed is determined, and an average path acceleration of the target interval path is determined based on a ratio between the speed difference and the target interval time.

[0141] For example, assuming that the starting optimal path speed of the starting path point is The optimal path speed at the end point is: The target interval time is Δt n , then the average path acceleration of the target interval path is

[0142] B. Determine the time difference between the trajectory planning moment and the start time of the target standard time period, and determine the planned path speed corresponding to the target robot at the trajectory planning moment based on the time difference and the average path acceleration.

[0143] In one embodiment, the time difference is determined based on the trajectory planning moment and the starting time of the target standard time period, and the product of the time difference and the average path acceleration is determined, and then the planned path speed corresponding to the target robot at the trajectory planning moment is determined based on the product result and the starting optimal path speed of the starting path point.

[0144] For example, assuming that the trajectory planning time is current_time, and the starting time of the target standard time period is t n , the average path acceleration is The initial optimal path speed at the starting path point is The planned path speed of the target robot at the time of trajectory planning is (current time -t n ).

[0145] C. Determine the planned path position corresponding to the target robot at the time of trajectory planning based on the planned path speed, the initial optimal path speed, and the time difference, and determine the planned joint position based on the planned path position.

[0146] In one embodiment, the average path speed of the planned path speed and the initial optimal path speed is determined, and the planned path position corresponding to the target robot at the trajectory planning time is determined according to the product of the average path speed and the time difference. For example, assuming that the time difference is current time -t n , the planned path speed is The initial optimal path speed is The planned path location

[0147] The polynomial coefficients in the first nonlinear relationship are determined according to the target standard time period, and the planned path position is substituted into the first nonlinear relationship to determine the planned joint position.

[0148] By determining the starting optimal path speed of the starting path point in the target interval path and the ending optimal path speed of the ending path point, and determining the average path acceleration of the target interval path according to the starting optimal path speed, the ending optimal path speed and the target interval time; determining the time difference according to the trajectory planning moment and the starting time of the target standard time period, and determining the planned path speed corresponding to the target robot at the trajectory planning moment according to the time difference and the average path acceleration; determining the planned path position corresponding to the target robot at the trajectory planning moment according to the planned path speed, the starting optimal path speed, and the time difference, and determining the planned joint position according to the planned path position, the effect of joint constraint trajectory planning for the target robot is achieved.

[0149] Optionally, in step C, "determining the planned joint position according to the planned path position" includes:

[0150] According to the target standard time period and the association relationship between the candidate standard time period and the candidate polynomial coefficients, the target polynomial coefficient associated with the target standard time period is determined, and the target polynomial coefficient is used as the polynomial coefficient in the first nonlinear relationship to obtain the optimal nonlinear relationship; the planned path position is substituted into the optimal nonlinear relationship to determine the planned joint position.

[0151] For the cubic nonlinear polynomial q() in the first nonlinear relationship q=q(s), an association relationship between each candidate standard time period and the candidate polynomial coefficient is established in advance, that is, the candidate polynomial coefficient associated with any candidate standard time period can be directly determined.

[0152] In one embodiment, the target standard time period is matched with the candidate standard time period, and the candidate polynomial coefficients associated with the candidate standard time period that matches the target standard time period are used as the target polynomial coefficients. The coefficients in the cubic nonlinear polynomial q() in the first nonlinear relationship q=q(s) are set as the target polynomial coefficients to obtain the optimal nonlinear relationship, and then the planned path position corresponding to the target robot at the time of trajectory planning is substituted into the optimal nonlinear relationship to determine the planned joint position corresponding to the target robot at the time of trajectory planning.

[0153] For example, assuming that the determined target polynomial coefficients are a1, b1, c1, d1, then q=as 3 +bs 2 The coefficient a in +cs+d is set to a1, the coefficient b is set to b1, the coefficient c is set to c1, and the coefficient d is set to d1, and the optimal nonlinear relationship q=a1s is obtained. 3 +b1s 2 +c1s+d1. Assume that the planned path position of the target robot at the time of trajectory planning is scur , then the planned joint position of the target robot at the time of trajectory planning is

[0154] By determining the target polynomial coefficient associated with the target standard time period according to the target standard time period and the association relationship between the candidate standard time period and the candidate polynomial coefficients, and using the target polynomial coefficient as the polynomial coefficient in the first nonlinear relationship, the optimal nonlinear relationship is obtained; the planned path position is substituted into the optimal nonlinear relationship to determine the planned joint position, thereby achieving the effect of dynamically determining the polynomial coefficient in the first nonlinear relationship according to the different target standard time periods, thereby ensuring the accuracy of the planned joint position finally calculated.

[0155] Embodiment 3

[0156] Figure 3 This is a schematic diagram of the structure of a robot joint constraint trajectory planning device provided by the third embodiment of the present invention. Figure 3 As shown, the device comprises:

[0157] A first nonlinear relationship determination module 31 is used to determine a first nonlinear relationship between a joint position and a path position of a target robot, a second nonlinear relationship between a joint velocity and a path velocity, and a third nonlinear relationship between a joint acceleration and a path velocity and a path acceleration;

[0158] A second nonlinear relationship determination module 32 is used to determine a fourth nonlinear relationship between the joint torque of the target robot and the path velocity and path acceleration according to the first nonlinear relationship, the second nonlinear relationship, the third nonlinear relationship and the robot dynamics equation;

[0159] a first parameter determination module 33, configured to determine a first parameter associated with the path speed and a second parameter associated with the path acceleration in the fourth non-linear relationship, and to determine a third parameter associated with the path speed and a fourth parameter associated with the path acceleration in the third non-linear relationship;

[0160] A second parameter determination module 34 is used to determine a fifth parameter in the first nonlinear constraint condition according to the first nonlinear constraint condition and the joint torque constraint condition of the fourth nonlinear relationship, and to determine a sixth parameter in the second nonlinear constraint condition according to the second nonlinear constraint condition and the joint acceleration constraint condition of the third nonlinear relationship;

[0161] a constraint condition determination module 35, for determining a standard path position of the target robot corresponding to a preset path point, and determining a path speed range of the preset path point according to the standard path position and the joint speed constraint of the second nonlinear relationship, and determining a target constraint condition of the target function according to the path speed range, the standard path position, the first parameter, the second parameter, the third parameter, the fourth parameter, the fifth parameter, and the sixth parameter;

[0162] The planning joint position determination module 36 is used to optimize the path speed of the target robot at the preset path points according to the target constraint conditions and the objective function, determine the optimal path speed of the target robot at the preset path points, and determine the planning joint position corresponding to the target robot at the trajectory planning time according to the optimal path speed, the standard path position, and the trajectory planning time.

[0163] Optionally, the first nonlinear relationship is:

[0164] q=q(s);

[0165] The second nonlinear relationship is:

[0166]

[0167] The third nonlinear relationship is:

[0168]

[0169] Among them, s represents the path position, q represents the joint position, represents the path speed, represents the joint acceleration, represents the path acceleration, and q() is a cubic nonlinear polynomial.

[0170] Optionally, the nonlinear relationship determining second module 32 is specifically used for:

[0171] Substituting the first nonlinear relationship, the second nonlinear relationship, and the third nonlinear relationship into the robot dynamics equation to obtain a fourth nonlinear relationship;

[0172] Among them, the fourth nonlinear relationship is:

[0173]

[0174] The dynamic equation of the robot is:

[0175]

[0176] Among them, A() represents the inertia matrix, B() represents the Coriolis force and centripetal force coefficient matrix, f() represents the gravity moment, and τ represents the joint moment.

[0177] Optionally, the parameter determination first module 33 is specifically used for:

[0178] The following parameter in the fourth nonlinear relationship is used as the first parameter:

[0179] A(q(s))q″(s)+q′(s) T B(q(s))q′(s);

[0180] The following parameters in the fourth nonlinear relationship are used as the second parameters:

[0181] A(q(s))q′(s).

[0182] Optionally, the parameter determination first module 33 is further configured to:

[0183] The following parameters in the third nonlinear relationship are used as the third parameters:

[0184] q″(s);

[0185] The following parameter in the third nonlinear relationship is used as the fourth parameter:

[0186] q′(s).

[0187] Optionally, the parameter determination second module 34 is specifically used for:

[0188] Substituting the joint torque constraint condition into the first nonlinear constraint condition to determine the fifth parameter in the first nonlinear constraint condition;

[0189] Among them, the joint torque constraint condition is:

[0190] τ min ≤τ≤τ max ;

[0191] Among them, τ represents the joint torque, τ min represents the minimum value of the joint torque, τ max Indicates the maximum value of the joint torque;

[0192] The first nonlinear constraint is:

[0193] Fτ≤g1;

[0194] in, g1 represents the fifth parameter,

[0195] Optionally, the parameter determination second module 34 is further configured to:

[0196] Substituting the joint acceleration constraint condition into the second nonlinear constraint condition to determine the sixth parameter in the second nonlinear constraint condition;

[0197] Among them, the joint acceleration constraint is:

[0198]

[0199] in, represents the joint acceleration, represents the minimum value of joint acceleration, Indicates the maximum value of joint acceleration;

[0200] The second nonlinear constraint is:

[0201]

[0202] in, g2 represents the sixth parameter,

[0203] Optionally, the constraint condition determination module 35 is specifically used to:

[0204] The joint velocity constraint condition is combined with the second nonlinear relationship to obtain the joint velocity relationship, and the standard path position is substituted into the joint velocity relationship to determine the path velocity range of the preset path point;

[0205] Among them, the joint velocity constraint is:

[0206]

[0207] in, represents the joint velocity, Indicates the minimum value of the joint velocity, Indicates the maximum value of the joint velocity;

[0208] The relationship between joint velocities is:

[0209]

[0210] The path speed range is:

[0211]

[0212] Optionally, the constraint condition determination module 35 is further configured to:

[0213] Determine a lower limit parameter and an upper limit parameter of the target constraint condition according to the fifth parameter and the sixth parameter, and determine a constraint matrix of the target constraint condition according to the first parameter, the second parameter, the third parameter and the fourth parameter;

[0214] Substitute the standard path position into the lower limit parameter, upper limit parameter, constraint matrix and path speed range to determine the target constraint condition of the objective function;

[0215] Among them, the objective function is:

[0216]

[0217] Where u represents the path acceleration x represents the path speed The square value of H represents the zero matrix, z is [2Δs, -1], Δs represents the distance between the current preset path point and the adjacent preset path point;

[0218] The target constraints are:

[0219]

[0220] Among them, lbA represents the lower limit parameter, ubA represents the upper limit parameter, u_low and u_up represent the lower and upper limits of the path acceleration range, respectively; x_low and x_up represent the lower and upper limits of the path speed range, respectively. represents the constraint matrix,

[0221]

[0222] Optionally, the planning joint position determination module 36 is specifically used for:

[0223] Determine the interval distance value of the candidate interval paths between the preset path points according to the standard path position of each preset path point, and determine the candidate interval time required for the target robot to travel to complete each candidate interval path according to the interval distance value and the optimal path speed of each preset path point;

[0224] The candidate interval times are superimposed to determine the candidate standard time periods for the target robot to travel to each candidate interval path, and the target standard time period to which the trajectory planning moment belongs is determined from the candidate standard time periods;

[0225] Determine a target interval time corresponding to a target standard time period from the candidate interval times, and determine a target interval path corresponding to the target standard time period from the candidate interval paths;

[0226] According to the target interval time, the target interval path, the target standard time period and the trajectory planning moment, the planned joint position corresponding to the target robot at the trajectory planning moment is determined.

[0227] Optionally, the planning joint position determination module 36 is further configured to:

[0228] determining a starting optimal path speed of a starting path point in the target interval path and a terminating optimal path speed of a terminating path point, and determining an average path acceleration of the target interval path based on the starting optimal path speed, the terminating optimal path speed and the target interval time;

[0229] Determine the time difference between the trajectory planning moment and the start time of the target standard time period, and determine the planned path speed corresponding to the target robot at the trajectory planning moment based on the time difference and the average path acceleration;

[0230] According to the planned path speed, the initial optimal path speed, and the time difference, the planned path position corresponding to the target robot at the trajectory planning moment is determined, and the planned joint position is determined according to the planned path position.

[0231] Optionally, the planning joint position determination module 36 is further configured to:

[0232] According to the target standard time period and the association relationship between the candidate standard time period and the candidate polynomial coefficient, determine the target polynomial coefficient associated with the target standard time period, and use the target polynomial coefficient as the polynomial coefficient in the first nonlinear relationship to obtain the optimal nonlinear relationship;

[0233] Substitute the planned path position into the optimal nonlinear relationship to determine the planned joint position.

[0234] The robot joint constraint trajectory planning device provided in the embodiment of the present invention can execute the robot joint constraint trajectory planning method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0235] Example 4

[0236] Figure 4 A schematic diagram of the structure of an electronic device 40 that can be used to implement an embodiment of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0237] like Figure 4As shown, the electronic device 40 includes at least one processor 41, and a memory connected to the at least one processor 41, such as a read-only memory (ROM) 42, a random access memory (RAM) 43, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 41 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 42 or the computer program loaded from the storage unit 48 to the random access memory (RAM) 43. In the RAM 43, various programs and data required for the operation of the electronic device 40 can also be stored. The processor 41, the ROM 42, and the RAM 43 are connected to each other through a bus 44. An input / output (I / O) interface 45 is also connected to the bus 44.

[0238] A number of components in the electronic device 40 are connected to the I / O interface 45, including: an input unit 46, such as a keyboard, a mouse, etc.; an output unit 47, such as various types of displays, speakers, etc.; a storage unit 48, such as a disk, an optical disk, etc.; and a communication unit 49, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 49 allows the electronic device 40 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0239] The processor 41 may be a variety of general and / or dedicated processing components with processing and computing capabilities. Some examples of the processor 41 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The processor 41 executes the various methods and processes described above, such as a joint constraint trajectory planning method for a robot.

[0240] In some embodiments, the joint constraint trajectory planning method of the robot can be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 48. In some embodiments, part or all of the computer program can be loaded and / or installed on the electronic device 40 via the ROM 42 and / or the communication unit 49. When the computer program is loaded into the RAM 43 and executed by the processor 41, one or more steps of the joint constraint trajectory planning method of the robot described above can be performed. Alternatively, in other embodiments, the processor 41 can be configured to execute the joint constraint trajectory planning method of the robot by any other appropriate means (e.g., by means of firmware).

[0241] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0242] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0243] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0244] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0245] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0246] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0247] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0248] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A robot joint constraint trajectory planning method, characterized in that: include: Determine a first nonlinear relationship between a joint position and a path position, a second nonlinear relationship between a joint velocity and a path velocity, and a third nonlinear relationship between a joint acceleration and the path velocity and the path acceleration of the target robot; Determine a fourth nonlinear relationship between the joint torque of the target robot and the path velocity and path acceleration according to the first nonlinear relationship, the second nonlinear relationship, the third nonlinear relationship and the robot dynamics equation; determining a first parameter associated with the path speed and a second parameter associated with the path acceleration in the fourth non-linear relationship, and determining a third parameter associated with the path speed and a fourth parameter associated with the path acceleration in the third non-linear relationship; Determine a fifth parameter in the first nonlinear constraint condition according to the first nonlinear constraint condition and the joint torque constraint condition of the fourth nonlinear relationship, and determine a sixth parameter in the second nonlinear constraint condition according to the second nonlinear constraint condition and the joint acceleration constraint condition of the third nonlinear relationship; Determine a standard path position of the target robot corresponding to a preset path point, and determine a path speed range of the preset path point according to the standard path position and the joint speed constraint of the second nonlinear relationship, and determine a target constraint of an objective function according to the path speed range, the standard path position, the first parameter, the second parameter, the third parameter, the fourth parameter, the fifth parameter, and the sixth parameter; The path speed of the target robot at the preset path point is optimized according to the target constraint condition and the objective function, the optimal path speed of the target robot at the preset path point is determined, and the planned joint position corresponding to the target robot at the trajectory planning moment is determined according to the optimal path speed, the standard path position, and the trajectory planning moment.

2. The method according to claim 1, characterized in that The first nonlinear relationship is: q=q(s); The second nonlinear relationship is: The third nonlinear relationship is: Wherein, s represents the path position, q represents the joint position, represents the path speed, represents the joint acceleration, represents the path acceleration, and q() is a cubic nonlinear polynomial.

3. The method according to claim 2, characterized in that Determining a fourth nonlinear relationship between the joint torque of the target robot and the path velocity and path acceleration according to the first nonlinear relationship, the second nonlinear relationship, the third nonlinear relationship and the robot dynamics equation includes: Substituting the first nonlinear relationship, the second nonlinear relationship, and the third nonlinear relationship into the robot dynamics equation to obtain the fourth nonlinear relationship; Wherein, the fourth nonlinear relationship is: The robot dynamics equation is: Among them, A() represents the inertia matrix, B() represents the Coriolis force and centripetal force coefficient matrix, f() represents the gravity moment, and τ represents the joint moment.

4. The method according to claim 3, characterized in that The determining of a first parameter associated with the path speed and a second parameter associated with the path acceleration in the fourth nonlinear relationship comprises: The following parameters in the fourth nonlinear relationship are used as the first parameters: A(q(s))q″(s)+q′(s) T B(q(s))q′(s); The following parameters in the fourth nonlinear relationship are used as the second parameters: A(q(s))q′(s).

5. The method according to claim 2, characterized in that: The determining of a third parameter associated with the path speed and a fourth parameter associated with the path acceleration in the third nonlinear relationship comprises: The following parameter in the third nonlinear relationship is used as the third parameter: q″(s); The following parameter in the third nonlinear relationship is used as the fourth parameter: q ′ (s)。 6. The method according to claim 3, characterized in that The step of determining the fifth parameter in the nonlinear constraint condition according to the first nonlinear constraint condition and the joint torque constraint condition of the fourth nonlinear relationship comprises: Substituting the joint torque constraint condition into the first nonlinear constraint condition to determine a fifth parameter in the first nonlinear constraint condition; Wherein, the joint torque constraint condition is: t min ≤τ≤τ max ; Among them, τ represents the joint torque, τ min represents the minimum value of the joint torque, τ max Indicates the maximum value of the joint torque; The first nonlinear constraint is: Fτ≤g1; in, g1 represents the fifth parameter, 7. The method according to claim 2, characterized in that Determining the sixth parameter in the second nonlinear constraint condition according to the second nonlinear constraint condition and the joint acceleration constraint condition of the third nonlinear relationship includes: Substituting the joint acceleration constraint condition into the second nonlinear constraint condition to determine a sixth parameter in the second nonlinear constraint condition; Wherein, the joint acceleration constraint condition is: in, represents the joint acceleration, represents the minimum value of joint acceleration, Indicates the maximum value of joint acceleration; The second nonlinear constraint is: in, g2 represents the sixth parameter, 8. The method according to claim 3, characterized in that The determining the path speed range of the preset path point according to the joint speed constraint condition of the standard path position and the second nonlinear relationship includes: The joint speed constraint condition and the second nonlinear relationship are combined to obtain a joint speed relationship, and the standard path position is substituted into the joint speed relationship to determine the path speed range of the preset path point; Wherein, the joint speed constraint condition is: in, represents the joint velocity, Indicates the minimum value of the joint velocity, Indicates the maximum value of the joint velocity; The joint velocity relationship is: The path speed range is:

9. The method according to claim 8, characterized in that Determining the target constraint condition of the target function according to the path speed range, the standard path position, the first parameter, the second parameter, the third parameter, the fourth parameter, the fifth parameter, and the sixth parameter includes: Determine a lower limit parameter and an upper limit parameter of the target constraint condition according to the fifth parameter and the sixth parameter, and determine a constraint matrix of the target constraint condition according to the first parameter, the second parameter, the third parameter and the fourth parameter; Substituting the standard path position into the lower limit parameter, the upper limit parameter, the constraint matrix and the path speed range to determine the target constraint condition of the target function; Wherein, the objective function is: Wherein, u represents the path acceleration x represents the path speed The square value of H represents the zero matrix, z is [2Δs, -1], Δs represents the distance between the current preset path point and the adjacent preset path point; The target constraints are: Wherein, lbA represents the lower limit parameter, ubA represents the upper limit parameter, u_low and u_up represent the lower limit and upper limit of the path acceleration range, respectively; x_low and x_up represent the lower limit and upper limit of the path speed range, respectively; represents the constraint matrix, 10. The method according to claim 2, characterized in that Determining the planned joint position of the target robot corresponding to the trajectory planning moment according to the optimal path speed, the standard path position, and the trajectory planning moment includes: Determine the interval distance value of the candidate interval paths between the preset path points according to the standard path position of each preset path point, and determine the candidate interval time required for the target robot to travel and complete each candidate interval path according to the interval distance value and the optimal path speed of each preset path point; The candidate interval times are superimposed to determine a candidate standard time period for the target robot to travel to each of the candidate interval paths, and a target standard time period to which the trajectory planning moment belongs is determined from the candidate standard time periods; Determine a target interval time corresponding to the target standard time period from the candidate interval times, and determine a target interval path corresponding to the target standard time period from the candidate interval paths; According to the target interval time, the target interval path, the target standard time period and the trajectory planning moment, the planned joint position corresponding to the target robot at the trajectory planning moment is determined.

11. The method according to claim 10, characterized in that The step of determining the planned joint position of the target robot corresponding to the trajectory planning moment according to the target interval time, the target interval path, the target standard time period and the trajectory planning moment comprises: Determine a starting optimal path speed of a starting path point in the target interval path and a terminating optimal path speed of a terminating path point, and determine an average path acceleration of the target interval path according to the starting optimal path speed, the terminating optimal path speed and the target interval time; Determine a time difference according to the trajectory planning moment and the starting time of the target standard time period, and determine a planned path speed of the target robot corresponding to the trajectory planning moment according to the time difference and the average path acceleration; The planned path position corresponding to the target robot at the trajectory planning moment is determined according to the planned path speed, the initial optimal path speed, and the time difference, and the planned joint position is determined according to the planned path position.

12. The method according to claim 11, characterized in that The step of determining the planned joint position according to the planned path position includes: According to the target standard time period and the association relationship between the candidate standard time period and the candidate polynomial coefficient, determine the target polynomial coefficient associated with the target standard time period, and use the target polynomial coefficient as the polynomial coefficient in the first nonlinear relationship to obtain the optimal nonlinear relationship; Substitute the planned path position into the optimal nonlinear relationship to determine the planned joint position.

13. A robot joint constraint trajectory planning device, characterized in that: include: A first nonlinear relationship determination module is used to determine a first nonlinear relationship between a joint position and a path position of a target robot, a second nonlinear relationship between a joint velocity and a path velocity, and a third nonlinear relationship between a joint acceleration and a path velocity and a path acceleration; A second nonlinear relationship determination module is used to determine a fourth nonlinear relationship between the joint torque of the target robot and the path velocity and path acceleration according to the first nonlinear relationship, the second nonlinear relationship, the third nonlinear relationship and the robot dynamics equation; a first parameter determination module, configured to determine a first parameter associated with the path speed and a second parameter associated with the path acceleration in the fourth nonlinear relationship, and to determine a third parameter associated with the path speed and a fourth parameter associated with the path acceleration in the third nonlinear relationship; a second parameter determination module, configured to determine a fifth parameter in the first nonlinear constraint condition according to the first nonlinear constraint condition and the joint torque constraint condition of the fourth nonlinear relationship, and to determine a sixth parameter in the second nonlinear constraint condition according to the second nonlinear constraint condition and the joint acceleration constraint condition of the third nonlinear relationship; a constraint condition determination module, used to determine a standard path position of the target robot corresponding to a preset path point, and determine a path speed range of the preset path point according to the standard path position and the joint speed constraint of the second nonlinear relationship, and determine a target constraint condition of an objective function according to the path speed range, the standard path position, the first parameter, the second parameter, the third parameter, the fourth parameter, the fifth parameter, and the sixth parameter; The planning joint position determination module is used to optimize the path speed of the target robot at the preset path point according to the target constraint condition and the objective function, determine the optimal path speed of the target robot at the preset path point, and determine the planning joint position corresponding to the target robot at the trajectory planning moment according to the optimal path speed, the standard path position, and the trajectory planning moment.

14. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the robot joint constraint trajectory planning method according to any one of claims 1 to 12.

15. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the robot joint constraint trajectory planning method according to any one of claims 1 to 12 when executed.

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