Inverse solution method and device of five-axis robot, computer equipment and storage medium

Abstract

The invention provides an inverse solution method and device of a five-axis robot, computer equipment and a storage medium, and relates to the technical field of robots, and the inverse solution method comprises the following steps: obtaining kinematics parameters of each joint axis of the five-axis robot; determining conversion relation information of the actuator coordinate system relative to the flange coordinate system and limitation information of the conversion relation information; wherein the limitation information represents an installation constraint condition of the actuator; when the expected pose information of the actuator is given under the limitation information, constructing a constraint equation between the expected pose information and the joint angle to be solved based on the kinematics parameters and the conversion relation information; and iteratively solving the constraint equation to obtain a joint angle to be solved. According to the method, the robot can be effectively guided to avoid the singular position to move, the solving problem caused by the singular position is avoided, the risk that the robot is out of control can be reduced by preventing the robot from entering the singular position by mistake, the safe operation performance of the robot is remarkably improved, and stable operation of the robot is ensured.

Description

Technical Field

[0001] The present invention relates to the field of robot technology, and in particular to an inverse solution method, device, computer equipment and storage medium for a five-axis robot. Background Art

[0002] Five-axis robots can be widely used in communications, power distribution, medical treatment, environmental protection, office furniture, metallurgical casting and other fields. They can not only improve work efficiency and quality, but also reduce the incidence of safety accidents.

[0003] In certain task scenarios, such as grinding, the actuator (such as a grinding tool) installed at the end of the five-axis robot does not need to have six degrees of freedom in space. Therefore, in order to save costs, the five-axis robot body is not designed with a fourth-axis rotation joint. Based on this special structure, the inverse kinematic solution of the five-axis robot no longer has an analytical solution, and can only be obtained through numerical iteration. However, the iterative method has the possibility of solution failure, especially when the robot is near a singular position, which causes the joint movement of the five-axis robot to be restricted or lose certain degrees of freedom. The numerical iteration method may not be able to find a solution, or the solution found is inaccurate, resulting in failure or non-convergence of the solution process. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide an inverse solution method, device, computer equipment and storage medium for a five-axis robot, which are used to clarify the singular positions of the five-axis robot, effectively guide the robot to avoid these positions for movement, avoid the problem of solving problems caused by the singular positions, and prevent the robot from mistakenly entering the singular positions, thereby reducing the risk of the robot losing control, significantly improving the robot's safe operation performance, and ensuring the robot's stable operation and efficient operation. In order to achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0005] In the first aspect, the present invention provides an inverse solution method for a five-axis robot, wherein an actuator is installed at the end of a flange of the five-axis robot, and the method comprises: obtaining the kinematic parameters of each joint axis of the five-axis robot; determining the transformation relationship information of the actuator coordinate system relative to the flange coordinate system and the restriction information of the transformation relationship information; wherein the restriction information represents the installation constraint conditions of the actuator; when the expected posture information of the actuator is given under the restriction information, constructing a constraint equation between the expected posture information and the joint angle to be solved based on the kinematic parameters and the transformation relationship information; and iteratively solving the constraint equation to obtain the joint angle to be solved.

[0006] In a second aspect, the present invention provides an inverse solution device for a five-axis robot, comprising: an acquisition module, used to obtain the kinematic parameters of each joint axis of the five-axis robot; wherein an actuator is installed at the end of the flange of the five-axis robot; a determination module, used to determine the transformation relationship information of the actuator coordinate system relative to the flange coordinate system and the restriction information of the transformation relationship information; wherein the restriction information represents the installation constraint conditions of the actuator; a construction module, used to construct a constraint equation between the expected posture information and the joint angle to be solved based on the kinematic parameters and the transformation relationship information when the expected posture information of the actuator is given under the restriction information; and a solution module, used to iteratively solve the constraint equation to obtain the joint angle to be solved.

[0007] In a third aspect, the present invention provides a computer device comprising: 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 inverse solution method of the five-axis robot as described in the first aspect.

[0008] In a fourth aspect, the present invention provides a storage medium comprising a computer program, which, when executed by a processor, implements the inverse solution method of the five-axis robot as described in the first aspect.

[0009] The inverse solution method, device, computer equipment and storage medium of the five-axis robot provided by the present invention first obtain the kinematic parameters of each joint axis of the five-axis robot. Subsequently, the conversion relationship between the actuator coordinate system and the flange coordinate system and the restriction conditions of the conversion relationship are established, in order to prevent the five-axis robot from moving to a singular position and being restricted in movement. Under these restriction conditions, when the desired posture information of the actuator is given, a constraint equation is constructed, which relates the desired posture information to the joint angle to be solved. Finally, by adopting an iterative method, the joint angle of the five-axis robot under the desired posture information can be solved. By clarifying the singular position of the five-axis robot and setting the installation restriction conditions of the actuator accordingly, the present invention can effectively guide the robot to avoid these positions for movement, avoid the problem of solving the problem caused by the singular position, and prevent the robot from mistakenly entering the singular position, reduce the risk of the robot being out of control, significantly improve the safe operation performance of the robot, and ensure the stable operation and efficient operation of the robot.

[0010] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0012] Figure 1 A schematic flow chart of an inverse solution method for a five-axis robot provided in an embodiment of the present invention;

[0013] Figure 2 A schematic diagram of modeling a five-axis robot DH provided in an embodiment of the present invention;

[0014] Figure 3 A configuration diagram of a five-axis robot used in a polishing scenario provided by an embodiment of the present invention;

[0015] Figure 4 A schematic diagram of joint angle error results during an experiment provided by an embodiment of the present invention;

[0016] Figure 5 A schematic diagram of error vector results during an experiment provided by an embodiment of the present invention;

[0017] Figure 6 A functional module diagram of an inverse solution device for a five-axis robot provided by an embodiment of the present invention;

[0018] Figure 7 A structural block diagram of a computer device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0019] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0021] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0022] Considering the possible solution failure problems that five-axis robots may encounter when using numerical iteration methods, the iterative solution process may face convergence difficulties, especially when the robot is close to a singular position. The so-called "singular position" refers to the robot's joint motion being restricted or some degrees of freedom being lost in certain specific postures. Near these positions, the numerical iteration method may not be able to successfully find a solution, or even if it is found, the accuracy of the solution may be insufficient, resulting in the failure of the solution process or failure to converge.

[0023] In order to solve the above technical problems, an embodiment of the present invention proposes an inverse solution method for a five-axis robot, aiming to ensure the stability when solving the inverse kinematic problem of a five-axis grinding robot by an iterative method. In the present invention, "inverse solution" can be understood as: under the premise of knowing the specific position and posture of the robot's end effector, calculating the angles required for each joint of the robot. The inverse solution method for a five-axis robot provided by an embodiment of the present invention is conducive to the safe operation and use of the robot, and ensures the stable operation and efficient operation of the robot.

[0024] In the embodiment of the present invention, the actuator refers to a tool that performs an operation task on a workpiece, including but not limited to a grinding tool, a cutting tool, a welding tool, etc., which is not limited here.

[0025] See also Figure 1 , Figure 1 : is a schematic flow chart of the inverse solution method of the five-axis robot provided in an embodiment of the present invention. The execution subject of the method may be a computer device, including steps S101 to S104, which are described as follows:

[0026] S101: Obtain kinematic parameters of each joint axis of the five-axis robot;

[0027] S102: Determine the conversion relationship information of the actuator coordinate system relative to the flange coordinate system and the restriction information of the conversion relationship information; wherein the restriction information represents the installation constraint condition of the actuator;

[0028] S103: when the desired posture information of the actuator is given under the restriction information, a constraint equation between the desired posture information and the joint angle to be solved is constructed based on the kinematic parameters and the conversion relationship information;

[0029] S104: Iteratively solve the constraint equation to obtain the joint angle to be solved.

[0030] In the inverse solution process provided by the embodiment of the present invention, the computer device first obtains the kinematic parameters of each joint axis of the five-axis robot. Subsequently, the conversion relationship between the actuator coordinate system and the flange coordinate system, as well as the restriction conditions of the conversion relationship, are established, the purpose of which is to prevent the five-axis robot from moving to a singular position and being restricted in motion. Under these restriction conditions, when the desired posture information of the actuator is given, a constraint equation is constructed, which relates the desired posture information to the joint angle to be solved. Finally, by adopting an iterative method, the joint angle to be solved of the five-axis robot under the desired posture information can be solved. By clarifying the singular positions of the five-axis robot and setting the installation restriction conditions of the actuator accordingly, the embodiment of the present invention can effectively guide the robot to avoid these positions for movement, avoid the problem of solving caused by the singular positions, and prevent the robot from mistakenly entering the singular position under specific circumstances. The risk of the robot being out of control can be reduced, and the safe operation performance of the robot is significantly improved, ensuring the stable operation and efficient operation of the robot.

[0031] Next, the embodiment of the present invention will explain the above inverse solution process in detail and clearly in conjunction with relevant drawings.

[0032] In step S101, the embodiment of the present invention adopts the standard DH method to establish a model for the five-axis grinding robot, thereby determining the kinematic parameters of each joint axis. As shown in FIG. 2, Figure 2 : is a schematic diagram of the modeling of the five-axis robot DH provided by an embodiment of the present invention. Figure 1 The flange coordinate system represented by Z5 and X5 and the omitted Y5. For simplicity, the following will take a joint axis as an example. Establish the joint coordinate system {i-1} at the i-th joint axis, i = 1, 2, 3, 4, 5. The construction method of the X-axis, Y-axis, and Z-axis of the joint coordinate system {i-1} is as follows:

[0033] Z i-1 : The i-th joint axis, the positive direction satisfies the right-hand screw rule.

[0034] X i-1: The common perpendicular line between the i-1th joint axis and the i-th joint axis, with the positive direction pointing from the i-1th joint axis to the i-th joint axis.

[0035] Y i-1 :Z i-1 With X i-1 The directions of Y i-1 The direction is determined according to the coordinate system establishment rules.

[0036] Based on the coordinate system constructed above, the DH parameters of the i-th joint axis are determined:

[0037] d i : Connecting rod offset, indicating that X i-1 Along Z i-1 Axis translation to X i distance;

[0038] a i : The length of the connecting rod, indicating that Z i-1 Along X i Axis translation to Z i distance;

[0039] α i : Connecting rod torsion angle, indicating that Z i-1 Along X i Axis rotation to Z i Angle

[0040] q i : represents the joint angle of the i-th joint, and offset represents the angle of the joint during modeling.

[0041] According to the above method, the coordinate system {0} corresponding to the five joint axes can be obtained, and the coordinate system {0} is the base coordinate system, coordinate system {1}, coordinate system {2}, coordinate system {3}, and coordinate system {4} of the five-axis robot. The DH parameters of each joint axis are shown in Table 1, which shows the modeling results of the five-axis robot. The parameters such as a1, a2, a3, and d5 in Table 1 are known.

[0042] Table 1

[0043] The i-th joint <![CDATA[d i ]]> <![CDATA[a i ]]> <![CDATA[α i ]]> offset 1 0 <![CDATA[a1]]> π / 2 0 2 0 <![CDATA[a2]]> 0 π / 2 3 0 <![CDATA[a3]]> π -π / 2 4 0 0 -π / 2 -π / 2 5 <![CDATA[d5]]> 0 0 0

[0044] The constraint equation is constructed using the above DH parameter table and the given desired position of the grinding tool and the Z-axis direction.

[0045] In step S102, the embodiment of the present invention takes into account that the five-axis robot does not have six degrees of freedom in space and can only realize the position and Z-axis direction control of the end effector. For ease of understanding, take the actuator as a grinding tool as an example, see Figure 3 , Figure 3A configuration diagram of a five-axis robot provided in an embodiment of the present invention for use in a polishing scene.

[0046] based on Figure 3 It can be seen that in the embodiment of the present invention, the actuator coordinate system T t Relative to flange coordinate system T f The conversion relationship information is expressed as Euler angles (ZYX) are used to represent the rotation relationship, then It can be expressed as Where X t ,Y t ,Z t T t Relative to T f The offset along the X-axis, Y-axis, and Z-axis, A t ,B t ,Z t T t Relative to T f The rotation angles around the X-axis, Y-axis, and Z-axis respectively. The rotation order is in Euler angle (ZYX) format.

[0047] To ensure that the position and Z-axis direction of the actuator mounted on the flange are controllable, that is, the iterative method is stable, The restriction information is as follows:

[0048]

[0049] Formula (1) restricts the conversion relationship information The offset distances in the X and Y directions and the angular relationship of the rotation angles A, B, and C must be determined. Otherwise, the robot will fall into a singular problem during the inverse solution process, resulting in instability in the inverse solution algorithm.

[0050] To help you understand the above limitations, see Figure 2 , Figure 2 This is a five-axis robot configuration diagram provided by an embodiment of the present invention. For example: when A t =C t = 0, B t The superposition of the angle of the 5th-axis joint causes the Z-axis of the actuator to be parallel to the axis of the 2nd-axis joint. At this time, the robot is in a singular position and the iterative method cannot converge to obtain a valid solution.

[0051] In addition, the five-axis robot has two singular positions, namely the shoulder singular point and the elbow singular point. The position of the shoulder singular point is that the intersection of the fifth-axis joint axis and the actuator axis is located near the first-axis joint axis; the elbow singular point is located when the third-axis joint angle is close to 90°. Therefore, when controlling the movement of the five-axis robot, the robot should be avoided as much as possible from being near the above three singular points. Based on the above steps S101 to S102, the implementation method of step S103 is described below.

[0052] In step S103, the embodiment of the present invention first assumes that the desired pose matrix of the actuator at a certain moment is The joint angles to be solved for the five-axis robot are q i , where i∈(1,2,…5), the detailed expression is as follows:

[0053]

[0054] Among them, [P x P y P z ] T is the position of the actuator coordinate system in the base coordinate system, [N x N y N z ] T is the direction vector of the actuator X axis in the base coordinate system, [ x O y O z ] T is the direction vector of the Y axis of the actuator coordinate system in the base coordinate system, [A x A y A z ] T is the direction vector of the actuator Z axis in the base coordinate system. The embodiment of the present invention can be given under the constraint of formula (1): And inversely solve the joint angle q required at this time.

[0055] In one embodiment of the present invention, step S103 may include the following steps a1 to a3, which are described as follows:

[0056] Step a1: Obtain the posture function of the flange; wherein the posture function includes the joint angle to be solved.

[0057] In the embodiment of the present invention, the transformation relationship between the joint coordinate systems can be written according to the DH method modeling information Where i∈(1,2,…,5). Substituting the DH parameter table in Table 1 into the DH parameter matrix, the homogeneous transformation matrix between each coordinate system can be obtained, and then the homogeneous transformation matrix between each coordinate system is multiplied in sequence to obtain the posture matrix of the flange coordinate system. That is, the posture function of the flange in the embodiment of the present invention.

[0058] Therefore, step a1 in the embodiment of the present invention can be implemented as follows: Step 1: Based on the kinematic parameters of each joint axis, the coordinate transformation relationship between the adjacent joint axis coordinate systems is obtained; Step 2: According to the coordinate transformation relationship between the adjacent joint axis coordinate systems, the pose function of the flange is constructed. For ease of understanding, the pose matrix of the flange coordinate system is expressed as So The calculation formula is as follows:

[0059]

[0060] Step a2: Based on the posture function of the flange and the transformation relationship information of the actuator coordinate system relative to the flange coordinate system, construct the desired posture function of the actuator.

[0061] In the embodiment of the present invention, the flange posture matrix Multiply by the flange coordinate system T obtained in step S102 t Relative to flange coordinate system T f Conversion relationship information The desired posture function of the actuator can be obtained, that is, the desired posture matrix described above is So The calculation formula is as follows:

[0062]

[0063] Step a3: Obtain the constraint equation according to the desired pose information and the desired pose function of the given actuator.

[0064] It is understandable that the purpose of inverse kinematics is to The information is solved to obtain the angle q of each joint i , then combining equations (3) and (5) we can get equation (6):

[0065]

[0066] Let each term on both sides of the above equation (6) be equal, and theoretically 12 constraint equations can be obtained. However, the embodiment of the present invention takes into account that the five-axis robot lacks a revolute joint and can only control the position and Z-axis direction of the end effector, that is, according to the angles q of each joint i and the rotation matrix of the actuator relative to the flange The desired pose matrix of the actuator can only be obtained by calculating formulas (4) and (5): The third column (A x ,A y ,A z )′ and the fourth column (P x ,P y ,P z )'information.

[0067] Therefore, after the position information of the actuator and the direction information of the Z axis of the actuator coordinate system are given, the implementation method of step a3 can be understood as: constructing an equation relationship between the position information of the actuator and the functional relationship corresponding to the position information in the desired posture function; constructing an equation relationship between the direction information of the Z axis of the actuator coordinate system and the functional relationship corresponding to the direction information of the Z axis of the actuator coordinate system in the desired posture function; and combining the equation relationships to obtain the constraint equation. For ease of understanding, the constraint equation is shown in equation (7):

[0068]

[0069] Based on the six constraint equations in formula (7), given A x ,A y ,A z ,p x ,p y ,P z as well as Based on this information, the angles of the robot's five joints can be solved.

[0070] Next, an embodiment of the present invention is described, based on the above constraint equation group (7), to iteratively solve the angles of the five joints of the robot under the given actuator posture information, see step S104.

[0071] In step S104, considering that the constraint equation group (7) is a multivariate nonlinear equation, the Gauss-Newton iteration method is used in the embodiment of the present invention when solving iteratively. Step S104 may include steps b1 to b5, which are described as follows:

[0072] Step b1: obtain the joint angle in the previous interpolation cycle;

[0073] In the embodiment of the present invention, the interpolation period refers to a fixed time interval used to calculate and generate the trajectory of the robot end effector in the robot motion control. During this time interval, the computer device calculates the angles of each joint of the robot.

[0074] Step b2: Substitute the joint angle into the constraint equation to determine the error vector of the actuator position information and the Z-axis direction information;

[0075] Step b3: determining the joint angle change based on the joint angle and the error vector;

[0076] Step b4: Determine whether the change in joint angle is within a preset accuracy range;

[0077] Step b5: If so, determine a new joint angle according to the joint angle change and the joint angle as the joint angle to be solved; otherwise, return to step b2 based on the new joint angle.

[0078] To facilitate understanding of the above process, let the joint angle of the previous interpolation cycle be q′, and substitute it into formula (5) to obtain the actuator pose matrix of the previous interpolation cycle: Then Substitute the right side of the equation into equation (7). Subtract the right side of the equation from the left side of equation (7) to obtain the error vector dY of the actuator's position information and the Z-axis direction information.

[0079]

[0080] Then, the computer device can determine the change amount of the joint angle based on the joint angle and the error vector. In the embodiment of the present invention, a preset formula is used to calculate the change amount of the joint angle, that is, the Jacobian matrix of the joint angle is first determined; according to the preset formula, the change amount of the joint angle is determined based on the Jacobian matrix and the error vector.

[0081] Among them, the Jacobian matrix J of the joint angles q1…q5 in the previous interpolation cycle is as follows:

[0082]

[0083] The preset formula for the joint angle change Δq is as follows:

[0084]

[0085] Furthermore, the computer device can determine whether Δq reaches the set accuracy range. If it does, the new joint angle q=q′+Δq is obtained as the joint angle to be solved; if it does not reach the accuracy range, the resulting new joint angle q=q′+Δq is used as the initial value of the next interpolation cycle iteration, and the process returns to step b2 until Δq reaches the set accuracy range. The q calculated at this time is used as the joint angle under the given posture information of the actuator, thereby achieving the purpose of inversely solving the joint angle of the five-axis robot under the premise of the expected posture information of the given actuator.

[0086] In order to verify the effect of the above inverse solution process provided by the embodiment of the present invention, detailed experimental data are given below for demonstration. Assume that the joint angle of the previous interpolation cycle is q 0, the detailed data are shown in equations (11), (12) and (13), where the unit of joint angle is radian (rad) and the unit of distance is meter (m).

[0087] q=[0.35 1.57 0.25 1.35 0.45](11)

[0088]

[0089] q 0 =[0.2443 1.4632 0.3438 1.2498 0.3414] (13)

[0090] The inverse solution process provided by the embodiment of the present invention is performed using the above data. After 5 iterations, the maximum value of Δq is 2.7×10 -16 , the maximum value of ‖dY‖ is 5.0×10 -16 ,The detailed iteration process is shown in Table 2.

[0091] Table 2

[0092]

[0093] In the above Table 2, compared with q 0 From the value of q, it can be seen that the angle of each joint has an error of more than 0.1 radians. Usually, the angle error between two adjacent interpolation cycles during robot motion is much smaller than 0.1 radians. The inverse solution method provided in the embodiment of the present invention solves the joint angle error to 2.7×10 -16 The error between position and Z direction ‖dY‖ is within 5.0×10 -16 The effectiveness of the inverse solution method proposed in the embodiment of the present invention is demonstrated. At the same time, the embodiment of the present invention can also generate 10 random 6 The joint angle values ​​are grouped and solved using the proposed inverse solution method. The solution results are shown in Figure 4 and Figure 5 As shown, the maximum error of Δq is 2.3×10 -12 , the maximum value of ‖dY‖ is 1.4×10 -13 , the maximum number of iterations is 6, which also proves the stability of the proposed method.

[0094] In summary, the inverse solution method of the five-axis robot provided by the embodiment of the present invention can directly control the position and Z-axis posture of the end effector from the perspective of scene requirements, use the standard DH method to build a model for the five-axis grinding robot, clarify the installation conditions of the end effector, analyze the position of the robot's singular point during the inverse solution, and finally use the Gaussian iteration method to obtain the joint angle of the actuator in any position in the workspace to ensure the stability of the iterative solution. The embodiment of the present invention clarifies the singular position of the five-axis robot and sets the installation restriction conditions of the actuator accordingly, which can effectively guide the robot to avoid these positions for movement. It avoids the problem of solving problems caused by singular positions and significantly improves the safe operation performance of the robot. By preventing the robot from mistakenly entering a singular position under certain circumstances, the risk of the robot losing control is reduced, ensuring the stable operation and efficient operation of the robot.

[0095] In order to execute the corresponding steps in the above embodiments and various possible methods, a five-step implementation method is provided below. Figure 6 , Figure 6 This is a functional module diagram of a five-axis robot inverse solution device provided in an embodiment of the present invention. It should be noted that the basic principle and technical effects of the five-axis robot inverse solution device provided in this embodiment are the same as those in the above embodiment. For the sake of brief description, for parts not mentioned in this embodiment, please refer to the corresponding contents in the above embodiment. The five-axis robot inverse solution device includes:

[0096] An acquisition module 601 is used to obtain the kinematic parameters of each joint axis of the five-axis robot;

[0097] A determination module 602 is used to determine the conversion relationship information of the actuator coordinate system relative to the flange coordinate system and the restriction information of the conversion relationship information; wherein the restriction information represents the installation constraint condition of the actuator;

[0098] A construction module 603 is used to construct a constraint equation between the desired posture information and the joint angle to be solved based on the kinematic parameters and the conversion relationship information when the desired posture information of the actuator is given under the constraint information;

[0099] The solving module 604 is used to iteratively solve the constraint equation to obtain the joint angle to be solved.

[0100] It is understandable that the acquisition module 601, the determination module 602, the construction module 603 and the solution module 604 can be executed in coordination. Figure 1 Each step in the process is performed to achieve the corresponding technical effect.

[0101] In an optional implementation, the inverse solution device 60 of the five-axis robot provided in the embodiment of the present invention has the same technical features as the inverse solution method of the five-axis robot provided in the above embodiment, so it can also solve the same technical problems and achieve the same technical effects. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process of the device described above can refer to the corresponding process in the above method embodiment, and will not be repeated here.

[0102] Optionally, the above modules can be stored in the form of software or firmware. Figure 7 The memory shown in FIG. 1 or the operating system (OS) of the computer device 70 may be fixed therein and may be Figure 7 Meanwhile, the data and program codes required for executing the above modules can be stored in the memory.

[0103] It should be noted that the division of modules in the above embodiments of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation. In addition, each functional unit in each embodiment of the present application may be integrated into a processing unit, or may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0104] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable an electronic device (which can be a personal computer, a server, or a network device, etc.) or a processor to perform all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), disk or optical disk and other media that can store program executable code.

[0105] The embodiment of the present invention further provides a computer device 70, see Figure 7 , Figure 7The block diagram of the computer device provided in the embodiment of the present invention includes a memory 701, a processor 702, and a communication interface 703. The memory 701, the processor 702, and the communication interface 703 are electrically connected to each other directly or indirectly to realize data transmission or interaction. For example, these components can be electrically connected to each other through one or more communication buses or signal lines.

[0106] Optionally, the bus can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 7 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0107] In the embodiment of the present invention, the processor 702 may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, and may implement or execute the methods, steps, and logic block diagrams disclosed in the embodiment of the present invention. A general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the method disclosed in the embodiment of the present invention may be directly embodied as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor. The software module may be located in the memory 701, and the processor 702 reads the program instructions in the memory 701 and completes the steps of the above method in combination with its hardware.

[0108] In the embodiment of the present invention, the memory 701 may be a non-volatile memory, such as a hard disk (HDD) or a solid-state drive (SSD), etc., or a volatile memory (Volatile Memory), such as RAM. The memory may also be any other medium that can be used to carry or store the desired program executable code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory in the embodiment of the present invention may also be a circuit or any other device that can realize a storage function, for storing instructions and / or data.

[0109] The memory 701 can be used to store software programs and modules, such as the instructions / modules of the inverse solution device 50 of the five-axis robot provided in the embodiment of the present invention, which can be stored in the memory 701 in the form of software or firmware (Firmware) or solidified in the operating system (OS) of the computer device 70. The processor 702 executes various functional applications and data processing by executing the software programs and modules stored in the memory 701. The communication interface 703 can be used for signaling or data communication with other node devices.

[0110] Understandably, Figure 7 The structure shown is for illustration only. The computer device 70 may also include Figure 7 More or fewer components as shown, or with Figure 7 Different configurations are shown. Figure 7 The components shown may be implemented in hardware, software or a combination thereof.

[0111] Based on the above embodiments, the present application also provides a storage medium, in which a computer program is stored. When the computer program is executed by a computer, the computer executes the inverse solution method of the five-axis robot provided in the above embodiments.

[0112] Based on the above embodiments, an embodiment of the present invention further provides a computer program. When the computer program is run on a computer, the computer executes the inverse solution method of the five-axis robot provided in the above embodiments.

[0113] Based on the above embodiments, an embodiment of the present invention further provides a chip, which is used to read a computer program stored in a memory and to execute the inverse solution method of the five-axis robot provided in the above embodiments.

[0114] A computer program product is also provided in an embodiment of the present invention, comprising instructions, which, when executed on a computer, enable the computer to execute the inverse solution method of the five-axis robot provided in the above embodiment.

[0115] The embodiments of the present invention are described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by instructions. These instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0116] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0117] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0118] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A five-axis robot inverse solution method, characterized in that: An actuator is installed at the end of the flange of the five-axis robot, and the method includes: Obtaining kinematic parameters of each joint axis of the five-axis robot; Determine the conversion relationship information of the actuator coordinate system relative to the flange coordinate system and the restriction information of the conversion relationship information; wherein the restriction information represents the installation constraint condition of the actuator; When the desired posture information of the actuator is given under the restriction information, a constraint equation between the desired posture information and the joint angle to be solved is constructed based on the kinematic parameters and the conversion relationship information; The constraint equation is solved iteratively to obtain the joint angle to be solved.

2. The inverse solution method of the five-axis robot according to claim 1, characterized in that: When the desired posture information of the actuator is given under the restriction information, a constraint equation between the desired posture information and the joint angle to be solved is constructed based on the kinematic parameters and the conversion relationship information, including: Obtaining a posture function of the flange; wherein the posture function includes the joint angle to be solved; Constructing an expected posture function of the actuator based on the posture function of the flange and the transformation relationship information of the actuator coordinate system relative to the flange coordinate system; The constraint equation is obtained according to the given expected posture information of the actuator and the expected posture function.

3. The inverse solution method of the five-axis robot according to claim 2, characterized in that: When the desired posture information of the actuator is given under the restriction information, a constraint equation between the desired posture information and the joint angle to be solved is constructed based on the kinematic parameters and the conversion relationship information, further comprising: Based on the kinematic parameters of each joint axis, the coordinate transformation relationship between the coordinate systems of adjacent joint axes is obtained; The position and posture function of the flange is constructed according to the coordinate transformation relationship between the adjacent joint axis coordinate systems.

4. The inverse solution method of the five-axis robot according to claim 2, characterized in that: The expected posture information includes the position information of the actuator and the direction information of the Z axis of the actuator coordinate system; the constraint equation is obtained based on the given expected posture information of the actuator and the expected posture function, including: Constructing an equation relationship between the position information of the actuator and a functional relationship corresponding to the position information in the desired posture function; Constructing an equation relationship between the direction information of the Z axis of the actuator coordinate system and a functional relationship corresponding to the direction information of the Z axis of the actuator coordinate system in the desired posture function; The constraint equation is obtained by combining the equation relationships.

5. The inverse solution method of the five-axis robot according to claim 2, characterized in that: Iteratively solving the constraint equation to obtain the joint angle to be solved includes: Get the joint angles in the last interpolation cycle; Substituting the joint angle into the constraint equation to determine the error vector of the position information of the actuator and the direction information of the Z axis; determining a joint angle change based on the joint angle and the error vector; Determining whether the change in the joint angle is within a preset accuracy range; If so, determine a new joint angle according to the joint angle change and the joint angle as the joint angle to be solved; otherwise, based on the new joint angle, return to the step of substituting the joint angle into the constraint equation to determine the error vector of the actuator's position information and the Z-axis direction information.

6. The inverse solution method of the five-axis robot according to claim 5, characterized in that: Determining a joint angle change based on the joint angle and the error vector includes: Determining the Jacobian matrix of the joint angles; According to a preset formula, based on the Jacobian matrix and the error vector, the change in the joint angle is determined.

7. The inverse solution method of the five-axis robot according to claim 1, characterized in that: Get the kinematic parameters of each joint axis of the five-axis robot, including: The kinematic model of the five-axis robot is established based on the standard DH method to obtain the kinematic parameters of each joint axis.

8. An inverse solution device for a five-axis robot, characterized in that: An actuator is installed at the end of the flange of the five-axis robot; the inverse solution device of the five-axis robot includes: The acquisition module is used to obtain the kinematic parameters of each joint axis of the five-axis robot; wherein; A determination module, used to determine the conversion relationship information of the actuator coordinate system relative to the flange coordinate system and the restriction information of the conversion relationship information; wherein the restriction information represents the installation constraint condition of the actuator; A construction module, used for constructing a constraint equation between the desired posture information and the joint angle to be solved based on the kinematic parameters and the conversion relationship information when the desired posture information of the actuator is given under the restriction information; The solution module is used to iteratively solve the constraint equation to obtain the joint angle to be solved.

9. A computer device, characterized in that: include: 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 inverse solution method of the five-axis robot as described in any one of claims 1 to 7.

10. A storage medium comprising a computer program, characterized in that When the computer program is executed by a processor, the inverse solution method of the five-axis robot described in any one of claims 1 to 7 is implemented.

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