CN114211502B - Robot load identification method and identification device - Google Patents
Robot load identification method and identification device Download PDFInfo
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- CN114211502B CN114211502B CN202210021915.5A CN202210021915A CN114211502B CN 114211502 B CN114211502 B CN 114211502B CN 202210021915 A CN202210021915 A CN 202210021915A CN 114211502 B CN114211502 B CN 114211502B
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
- B25J9/00—Programme-controlled manipulators
- B25J9/16—Programme controls
- B25J9/1628—Programme controls characterised by the control loop
- B25J9/1633—Programme controls characterised by the control loop compliant, force, torque control, e.g. combined with position control
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
- B25J9/00—Programme-controlled manipulators
- B25J9/16—Programme controls
- B25J9/1602—Programme controls characterised by the control system, structure, architecture
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
- B25J9/00—Programme-controlled manipulators
- B25J9/16—Programme controls
- B25J9/1602—Programme controls characterised by the control system, structure, architecture
- B25J9/1605—Simulation of manipulator lay-out, design, modelling of manipulator
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
- B25J9/00—Programme-controlled manipulators
- B25J9/16—Programme controls
- B25J9/1656—Programme controls characterised by programming, planning systems for manipulators
- B25J9/1664—Programme controls characterised by programming, planning systems for manipulators characterised by motion, path, trajectory planning
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Abstract
The present disclosure provides a robot load identification method, comprising: obtaining a dynamic model of the robot according to the structure of the robot; generating a zero space motion excitation track; obtaining a torque theoretical value required by the motion of the robot body according to a dynamic model of the robot and a zero-space motion excitation track of the robot; after the robot is additionally provided with a load, the robot is operated to run a zero-space motion excitation track, and the actual torque value of each joint is acquired in real time; and obtaining an inertial parameter set of the load of the robot according to the torque theoretical value required by the motion of the robot body and the actual torque value of each joint. The disclosure also provides an identification device, an electronic device and a readable storage medium.
Description
Technical Field
The disclosure relates to the technical field of robot control, and in particular relates to a robot load identification method, an identification device, electronic equipment and a readable storage medium.
Background
In the actual operation process of the robot, the end load of the robot may change, if the control system does not timely compensate the gravity moment and the inertia moment generated by the load, the motion precision of the robot may be poor, the dynamic performance may be reduced, and even under certain pose, the resonance of the load and the connecting rod is caused. Therefore, the rapid and accurate identification of the load dynamics parameters is one of the keys for realizing the high-precision control of the robot.
In the prior art, a multidimensional force sensor is arranged at the tail end of a robot to sense the stress information of the tail end of the robot, the robot is operated to enable the tail end of the robot to be in different poses respectively, stress feedback information of the sensor under the different poses is collected, and mass center parameters of a tail end load are deduced.
However, this method requires an additional multi-dimensional force sensor, thereby resulting in an increase in cost, and requires conversion of the tip force into each joint torque indirectly through jacobian matrix computation.
The Chinese patent application ZL201610967758.1 discloses a method and a module for identifying the load of a six-axis robot, but as the six-axis robot does not have a zero space, the method can correspondingly lead the load to move when being applied to seven or more degrees of freedom, and the robot is easy to be dangerous when running an excitation track.
Disclosure of Invention
In order to solve one of the above technical problems, the present disclosure provides a robot load identification method, an identification device, an electronic apparatus, and a readable storage medium.
According to one aspect of the present disclosure, there is provided a robot load recognition method, including:
obtaining a dynamic model of the robot according to the structure of the robot;
generating a zero space motion excitation track;
obtaining a torque theoretical value required by the motion of the robot body according to a dynamic model of the robot and a zero-space motion excitation track of the robot;
after the robot is additionally provided with a load, the robot is operated to run a zero-space motion excitation track, and the actual torque value of each joint is acquired in real time; and
and obtaining an inertial parameter set of the load of the robot according to the torque theoretical value required by the motion of the robot body and the actual torque value of each joint.
According to the robot load identification method of at least one embodiment of the present disclosure, a load inertia parameter set is obtained according to a zero-space motion excitation trajectory.
According to a robot load recognition method of at least one embodiment of the present disclosure, the joint includes a torque sensor for detecting an actual torque value of the joint driving link.
According to a robot load recognition method of at least one embodiment of the present disclosure, generating a zero-space motion excitation trajectory includes:
obtaining a zero space projection matrix of the robot according to the structural parameters of the robot;
obtaining a zero space motion direction of the robot according to a zero space projection matrix of the robot;
the zero space movement track data are obtained by planning the zero space movement speed;
taking the characteristic of a regression matrix related to the zero-space motion trail data as an objective function, and optimizing the zero-space motion trail data; and
and obtaining the zero-space motion excitation track through the optimized value of the zero-space motion track data.
According to the robot load identification method of at least one embodiment of the present disclosure, a torque difference value is obtained according to a theoretical torque value required by the motion of the robot body and actual torque values of each joint; and obtaining an inertial parameter set of the load according to the torque difference and a dynamic model about the zero-space motion excitation trajectory.
According to a robot load identification method of at least one embodiment of the present disclosure, obtaining an inertial parameter set of a load from a torque difference and a kinetic model about a zero-space motion excitation trajectory includes:
wherein ,the method comprises the steps that a dynamic model of a load about a zero-space motion excitation track is adopted, and phi load is an inertial parameter set of the load; τ load Torque required to drive the load motion; τ link The torque required to drive the movement of the connecting rod itself；τ sensor A read value for the torque sensor;
optionally, according to a preset sampling period, obtaining a dynamic model of K groups of loads about the zero-space motion excitation track and K groups of torque differences, and enabling the K groups of loads to be in a state of:
and obtaining an inertial parameter set of the load according to a least square method.
According to another aspect of the present disclosure, there is provided a robot load recognition apparatus including:
the dynamic model acquisition module is used for acquiring a dynamic model of the robot according to the structure of the robot;
the excitation track generation module is used for generating a zero-space motion excitation track;
the connecting rod torque calculation module is used for obtaining a torque theoretical value required by the robot body motion according to a dynamic model of the robot and a zero-space motion excitation track of the robot;
the load torque acquisition module is used for operating the robot to run a zero-space motion excitation track after the robot is additionally provided with a load, and acquiring actual torque values of all joints in real time through the load torque acquisition module; and
and the load identification module is used for obtaining an inertial parameter set of the load of the robot according to the torque theoretical value required by the motion of the robot body and the actual torque value of each joint.
According to the robot load identification device of at least one embodiment of the present disclosure, a load inertia parameter set is obtained according to a zero-space motion excitation track;
optionally, the joint comprises a torque sensor for detecting an actual torque value of the joint drive link;
optionally, generating the zero-space motion excitation trajectory includes:
obtaining a zero space projection matrix of the robot according to the structural parameters of the robot;
obtaining a zero space motion direction of the robot according to a zero space projection matrix of the robot;
the zero space movement track data are obtained by planning the zero space movement speed;
taking the characteristic of a regression matrix related to the zero-space motion trail data as an objective function, and optimizing the zero-space motion trail data; and
obtaining a zero-space motion excitation track through the optimized value of the zero-space motion track data;
optionally, obtaining a torque difference value according to a torque theoretical value required by the robot body motion and actual torque values of all joints; obtaining an inertial parameter set of the load according to the torque difference value and a dynamic model about the zero-space motion excitation track;
optionally, obtaining the inertial parameter set of the load from the torque difference and the kinetic model of the excitation trajectory for the null-space motion comprises:
wherein ,the method comprises the steps that a dynamic model of a load about a zero-space motion excitation track is adopted, and phi load is an inertial parameter set of the load; τ load Torque required to drive the load motion; τ link The torque required to drive the motion of the link itself; τ sensor A read value for the torque sensor;
optionally, according to a preset sampling period, obtaining a dynamic model of K groups of loads about the zero-space motion excitation track and K groups of torque differences, and enabling the K groups of loads to be in a state of:
and obtaining an inertial parameter set of the load according to a least square method.
According to another aspect of the present disclosure, there is provided an electronic device, including:
a memory storing execution instructions; and
and the processor executes the execution instructions stored in the memory, so that the processor executes the method.
According to another aspect of the present disclosure, there is provided a readable storage medium having stored therein execution instructions which when executed by a processor are adapted to carry out the method described above.
Drawings
The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the disclosure and together with the description serve to explain the principles of the disclosure.
Fig. 1 is a flowchart of a robot load recognition method according to one embodiment of the present disclosure.
Fig. 2 is a flow chart of generating a zero-space motion excitation trajectory according to one embodiment of the present disclosure.
Fig. 3 is a schematic structural view of a robot load recognition device according to one embodiment of the present disclosure.
Detailed Description
The present disclosure is described in further detail below with reference to the drawings and the embodiments. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant content and not limiting of the present disclosure. It should be further noted that, for convenience of description, only a portion relevant to the present disclosure is shown in the drawings.
In addition, embodiments of the present disclosure and features of the embodiments may be combined with each other without conflict. The technical aspects of the present disclosure will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.
Unless otherwise indicated, the exemplary implementations/embodiments shown are to be understood as providing exemplary features of various details of some ways in which the technical concepts of the present disclosure may be practiced. Thus, unless otherwise indicated, features of the various implementations/embodiments may be additionally combined, separated, interchanged, and/or rearranged without departing from the technical concepts of the present disclosure.
The use of cross-hatching and/or shading in the drawings is typically used to clarify the boundaries between adjacent components. As such, the presence or absence of cross-hatching or shading does not convey or represent any preference or requirement for a particular material, material property, dimension, proportion, commonality between illustrated components, and/or any other characteristic, attribute, property, etc. of a component, unless indicated. In addition, in the drawings, the size and relative sizes of elements may be exaggerated for clarity and/or descriptive purposes. While the exemplary embodiments may be variously implemented, the specific process sequences may be performed in a different order than that described. For example, two consecutively described processes may be performed substantially simultaneously or in reverse order from that described. Moreover, like reference numerals designate like parts.
When an element is referred to as being "on" or "over", "connected to" or "coupled to" another element, it can be directly on, connected or coupled to the other element or intervening elements may be present. However, when an element is referred to as being "directly on," "directly connected to," or "directly coupled to" another element, there are no intervening elements present. For this reason, the term "connected" may refer to physical connections, electrical connections, and the like, with or without intermediate components.
For descriptive purposes, the present disclosure may use spatially relative terms such as "under … …," under … …, "" under … …, "" lower, "" above … …, "" upper, "" above … …, "" higher "and" side (e.g., as in "sidewall"), etc., to describe one component's relationship to another (other) component as illustrated in the figures. In addition to the orientations depicted in the drawings, the spatially relative terms are intended to encompass different orientations of the device in use, operation, and/or manufacture. For example, if the device in the figures is turned over, elements described as "under" or "beneath" other elements or features would then be oriented "over" the other elements or features. Thus, the exemplary term "below" … … can encompass both an orientation of "above" and "below". Furthermore, the device may be otherwise positioned (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, when the terms "comprises" and/or "comprising," and variations thereof, are used in the present specification, the presence of stated features, integers, steps, operations, elements, components, and/or groups thereof is described, but the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof is not precluded. It is also noted that, as used herein, the terms "substantially," "about," and other similar terms are used as approximation terms and not as degree terms, and as such, are used to explain the inherent deviations of measured, calculated, and/or provided values that would be recognized by one of ordinary skill in the art.
Fig. 1 is a flowchart of a robot load recognition method according to one embodiment of the present disclosure.
As shown in fig. 1, the robot load recognition method of the present disclosure is a method applied to seven-axis and above industrial robots or collaborative robots, and the seven-axis and above industrial robots have a null space.
Specifically, the robot may include an industrial robot arm or a cooperative robot arm, the robot arm including a plurality of joints and a plurality of links, wherein the joints may allow relative rotation between two links connected to the joints; of course, the robotic arm may also include degrees of freedom of movement, and the linkage may also include an end effector.
Based on this, the robot load identification method of the present disclosure includes: 102. obtaining a dynamic model of the robot according to the structure of the robot; 104. generating a zero space motion excitation track; 106. obtaining a torque theoretical value required by the motion of the robot body according to a dynamic model of the robot and a zero-space motion excitation track of the robot; 108. after the robot is additionally provided with a load, the robot is operated to run a zero-space motion excitation track, and the actual torque value of each joint is acquired in real time; and 110, obtaining an inertial parameter set of the load of the robot according to the theoretical torque value required by the motion of the robot body and the actual torque value of each joint.
Each step of the robot load recognition method of the present disclosure is described in detail below.
In 102, the robot may be modeled to obtain a kinetic model of the robot, in particular, by newton-euler method, and from the robot kinetic model, the kinetic model is formed as a function of the position, velocity, acceleration and moment required by the joints to drive the links in motion.
Of course, the inertial parameter set of the robot can also be obtained by a model of the robot, and in general, the inertial parameter set includes: mass (m), centroid (mr) x ，mr y ，mr z ) Inertia, and moment of inertia (I xx ，I xy ，I xz ，I yy ，I yz ，I zz )。
At 104, a zero-space motion excitation trajectory is generated from the predetermined joint space and Cartesian space parameter limits of the robot.
Preferably, the parameter limit value of the joint space of the robot includes that the pose of the end effector of the robot is within the range of the reachable working space of the robot, namely:s (q) is the pose of the end effector corresponding to the robot when the joint position is q in the working space; s is the robot reachable working space.
The cartesian space parameter constraints of the robot include: the position of the connecting rod is between the maximum position and the minimum position of the connecting rod; the speed of the connecting rod is between the maximum speed and the minimum speed, and the acceleration of the connecting rod is between the maximum acceleration and the minimum acceleration, namely:
wherein q is the position of the connecting rod,speed of connecting rod, ++>Acceleration of the connecting rod, q min Is the minimum position of the connecting rod, q max Is the maximum position of the connecting rod; />Is the minimum speed of the connecting rod, namely the maximum speed in the opposite direction; />Maximum speed for the connecting rod; />As the minimum acceleration of the connecting rod,i.e. the maximum acceleration in the opposite direction; />Is the maximum acceleration of the connecting rod.
Fig. 2 is a flow chart of generating a zero-space motion excitation trajectory according to one embodiment of the present disclosure.
Specifically, as shown in fig. 2, generating the zero-space motion excitation trajectory includes: 1041. obtaining a zero space projection matrix of the robot according to the structural parameters of the robot; 1042. obtaining a zero space motion direction of the robot according to a zero space projection matrix of the robot; 1043. the zero space movement track data are obtained by planning the zero space movement speed; 1044. taking the characteristic of a regression matrix related to the zero-space motion trail data as an objective function, and optimizing the zero-space motion trail data; and 1045, obtaining a zero-space motion excitation track through the optimized value of the zero-space motion track data.
The method comprises the steps that a zero space of a robot can be obtained according to structural parameters of the robot, and a zero space projection matrix of the robot is obtained; when the zero-space motion track data is acquired, the initial value of the zero-space motion speed of the robot is designated, the initial value of the position and the initial value of the acceleration of the connecting rod of the robot are obtained according to the initial value of the zero-space motion speed of the robot, and the initial value of the zero-space track data is obtained.
Accordingly, a motion vector regarding the position, speed, and acceleration of each link is included in the zero-space motion excitation trajectory, and the robot outputs a corresponding torque to the control joint according to the motion vector, so that the robot can move along the zero-space motion excitation trajectory.
For each link, its position, velocity and acceleration are expressed by:
wherein q0 is the offset of each link, i.e., the starting position of the zero-space motion; i n Is a matrix of units, J,respectively a jacobian matrix and a pseudo-inverse thereof. />Is a zero-space projection matrix, N represents the basis of the zero-space projection matrix, which represents the direction of zero-space motion. ζ is any non-zero scalar in units of (rad/s), and the speed of movement of each link can be specified by specifying the value of ζ.
And combining the preset joint space and Cartesian space parameter limit values of the robot and the minimum condition number of the dynamic model related to the initial value of the zero space trajectory data to obtain the motion vector of each connecting rod corresponding to the robot at a certain position, and generating a zero space motion excitation trajectory through the motion vectors at a plurality of positions.
When the speed of each connecting rod of the robot is obtained, the speed range can be traversed by a preset step length in the speed range of the connecting rod, a speed value corresponding to the minimum condition number of the dynamic model related to the initial value of the zero space trajectory data is obtained, and the motion vector of each connecting rod corresponding to the robot at a certain position is obtained by the speed value and the speed direction; of course, the motion vector may be obtained in other ways.
In an alternative embodiment of the present disclosure, at 106, the theoretical torque required for the robot body motion is obtained from the kinetic model of the robot and the robot zero-space motion excitation trajectory.
In this case, the required torque theoretical value may be an actual torque value when the robot drives the links at each joint when the robot is not loaded with a load.
In the actual use process of the robot, the load is generally directly replaced, and the inertial parameter set of the new load is identified, so that the required torque theoretical value for the motion vector in the zero-space motion excitation track of the robot can be obtained through modeling the robot and calculating through the robot model.
At 108, after the robot is loaded, the robot is operated to run a zero-space motion excitation track, and the actual torque value of the connecting rod side of each joint is acquired in real time.
Here, the robot loading includes a case where the robot end effector does not have a load, but directly mounts a load, and also includes a case where the robot end effector replaces a new load; both cases require load identification.
More preferably, each joint of the robot includes a torque sensor mounted on a link side of the joint for detecting an output torque of the joint to the link, thereby obtaining an actual torque value of the link side of the joint in real time through the torque sensor.
At 110, an inertial parameter set of the load of the robot is obtained from the theoretical torque value required for the robot body motion and the actual torque values of the link sides of the joints.
In the case of a robot with a load applied to the end effector, the output torque on the link side of each joint includes the torque required to drive the link itself, i.e., the link torque (τ link ) And the torque required to drive the load in motion, i.e. the load torque (τ load ). The two torque components act together on the torque sensor and can be obtained by means of direct reading.
When the robot moves according to the zero-space motion excitation track, the connecting rod torque and the load torque are uncorrelated with each other, and the inertia parameters are mutually independent, and correspondingly:
τ seneor ＝τ linA +τ load 。
because the feedback data of the torque sensor is the combined action result of the connecting rods and the load, in order to reduce the calculation error of the torque theoretical value required by the movement of each connecting rod of the robot and improve the load identification precision, the inertial parameter set of the robot when the load is not added should be identified with high precision, and the dynamics model of the robot with high precision is obtained.
And after the inertial parameter set of the robot is corrected and the accuracy is improved when the load is not added, identifying the inertial parameter set of the load.
Correspondingly, the load torque
wherein For a dynamic model of the load with respect to the zero-space motion excitation trajectory, which is a coefficient term independent of the inertial parameter set of the load, phi load Is the inertial parameter set of the load.
When the robot moves in the zero space motion excitation track, a dynamic model of k groups of loads relative to the zero space motion excitation track and k groups of torque difference values are obtained according to a preset sampling period, and fitting values of inertial parameter sets of the loads can be obtained according to a least square method.
That is to say,
wherein ,a kinetic model of the excitation trajectory for the first set of loads with respect to the zero-space motion;for the k-th group of loads, a dynamic model of the excitation trajectory with respect to the zero-space motion, < >>For a first set of load torques; />The k-th group load torque, wherein k is an integer greater than or equal to 2.
Therefore, when the robot load is identified, the torque is directly read through the torque sensor at the connecting rod side, and the load is identified with high accuracy through calculation and pushing of other variables in an unordered manner. Moreover, in the robot load recognition process in the prior art, such as the chinese patent No. ZL201610967758.1, the feasibility of the excitation track needs to be checked, and if the operation of the excitation track can cause the collision between the robot load and the robot body, the excitation track needs to be re-optimized; however, in the present disclosure, by using the characteristics of the zero-space motion of the robot with seven axes or more, it is possible to ensure that the load is stationary with respect to the robot coordinate system during load identification, and avoid the risk during the actual running of the excitation track of the zero-space motion.
Moreover, the load can be identified more quickly and accurately through the optimized zero-space motion excitation track.
Fig. 3 is a schematic structural view of a robot load recognition device according to one embodiment of the present disclosure.
According to another aspect of the present disclosure, as shown in fig. 3, the present disclosure provides a robot load recognition apparatus, the robot including a plurality of joints and a plurality of links, and having two adjacent links connected by the joints such that the number of degrees of freedom of the robot is seven or more, whereby the robot has a zero space, comprising: a dynamics model acquisition module 210, an excitation trajectory generation module 220, a link torque calculation module 230, a load torque acquisition module 240, and a load identification module 250.
The dynamics model obtaining module 210 is configured to obtain a dynamics model of the robot according to a structure of the robot; the excitation track generation module 220 is configured to generate a zero-space motion excitation track; the link torque calculation module 230 is configured to obtain a torque theoretical value required by the robot body motion according to a dynamics model of the robot and a robot zero-space motion excitation track; when the robot is additionally provided with a load, the robot is operated to run a zero-space motion excitation track, and the actual torque value of each joint is acquired in real time through the load torque acquisition module 240; and the load identification module 250 is used for obtaining an inertial parameter set of the load of the robot according to the theoretical torque value required by the motion of the robot body and the actual torque value of each joint.
In the present disclosure, a robot may be modeled to obtain a kinetic model of the robot, and in particular, a kinetic model of the robot may be obtained by a newton's euler method, and from the kinetic model of the robot, the kinetic model is formed as a function of a position, a speed, an acceleration, and a moment required when a joint drives the links to move.
Of course, the inertial parameter set of the robot can also be obtained by a model of the robot, and in general, the inertial parameter set includes: mass (m), centroid (mr) x ，mr y ，mr z ) Inertia, and moment of inertia (I xx ，I xy ，I xz ，I yy ，I yz ，I zz )。
In the present disclosure, a zero-space motion excitation trajectory is generated according to a preset joint space and a cartesian space parameter limit value of a robot.
Preferably, the parameter limit value of the joint space of the robot includes that the pose of the end effector of the robot is within the range of the reachable working space of the robot, namely:s (q) is the pose of the end effector corresponding to the robot when the joint position is q in the working space; s is the robot reachable working space.
The cartesian space parameter constraints of the robot include: the position of the connecting rod is between the maximum position and the minimum position of the connecting rod; the speed of the connecting rod is between the maximum speed and the minimum speed, and the acceleration of the connecting rod is between the maximum acceleration and the minimum acceleration, namely:
wherein q is the position of the connecting rod,speed of connecting rod, ++>Acceleration of the connecting rod, q min Is the minimum position of the connecting rod, q max Is the maximum position of the connecting rod; />Is the minimum speed of the connecting rod, namely the maximum speed in the opposite direction; />Maximum speed for the connecting rod; />The minimum acceleration of the connecting rod, namely the maximum acceleration in the opposite direction; />Is the maximum acceleration of the connecting rod.
Fig. 2 is a flow chart of generating a zero-space motion excitation trajectory according to one embodiment of the present disclosure.
Specifically, as shown in fig. 2, generating the zero-space motion excitation trajectory includes: 1041. obtaining a zero space projection matrix of the robot according to the structural parameters of the robot; 1042. obtaining a zero space motion direction of the robot according to a zero space projection matrix of the robot; 1043. the zero space movement track data are obtained by planning the zero space movement speed; 1044. taking the characteristic of a regression matrix related to the zero-space motion trail data as an objective function, and optimizing the zero-space motion trail data; and 1045, obtaining a zero-space motion excitation track through the optimized value of the zero-space motion track data.
Accordingly, a motion vector regarding the position, speed, and acceleration of each link is included in the zero-space motion excitation trajectory, and the robot outputs a corresponding torque to the control joint according to the motion vector, so that the robot can move along the zero-space motion excitation trajectory.
For each link, its position, velocity and acceleration are expressed by:
wherein q0 is the offset of each link, i.e., the starting position of the zero-space motion; i n Is a matrix of units, J,respectively a jacobian matrix and a pseudo-inverse thereof. />Is a zero-space projection matrix, N represents the basis of the zero-space projection matrix, which represents the direction of zero-space motion. ζ is any non-zero scalar in units of (rad/s), and the speed of movement of each link can be specified by specifying the value of ζ.
And combining the preset joint space and Cartesian space parameter limit values of the robot and the minimum condition number of the dynamic model related to the initial value of the zero space trajectory data to obtain the motion vector of each connecting rod corresponding to the robot at a certain position, and generating a zero space motion excitation trajectory through the motion vectors at a plurality of positions.
When the speed of each connecting rod of the robot is obtained, the speed range can be traversed by a preset step length in the speed range of the connecting rod, a speed value corresponding to the minimum condition number of the dynamic model related to the initial value of the zero space trajectory data is obtained, and the motion vector of each connecting rod corresponding to the robot at a certain position is obtained by the speed value and the speed direction; of course, the motion vector may be obtained in other ways.
In an alternative embodiment of the present disclosure, the theoretical torque required for the robot body motion is obtained from a kinetic model of the robot and a robot zero-space motion excitation trajectory.
In this case, the required torque theoretical value may be an actual torque value when the robot drives the links at each joint when the robot is not loaded with a load.
In the actual use process of the robot, the load is generally directly replaced, and the inertial parameter set of the new load is identified, so that the required torque theoretical value for the motion vector in the zero-space motion excitation track of the robot can be obtained through modeling the robot and calculating through the robot model.
In the method, after the robot is additionally provided with a load, the robot is operated to run a zero-space motion excitation track, and the actual torque value of the connecting rod side of each joint is collected in real time.
Here, the robot loading includes a case where the robot end effector does not have a load, but directly mounts a load, and also includes a case where the robot end effector replaces a new load; both cases require load identification.
More preferably, each joint of the robot includes a torque sensor mounted on a link side of the joint for detecting an output torque of the joint to the link, thereby obtaining an actual torque value of the link side of the joint in real time through the torque sensor.
In the present disclosure, an inertial parameter set of a load of a robot is obtained from a theoretical torque value required for a robot body motion and an actual torque value of a link side of each joint.
In the case of a robot with a load applied to the end effector, the output torque on the link side of each joint includes the torque required to drive the link itself, i.e., the link torque (τ link ) And the torque required to drive the load in motion, i.e. the load torque (τ load ). The two torque components act together on the torque sensor and can be obtained by means of direct reading.
When the robot moves according to the zero-space motion excitation track, the connecting rod torque and the load torque are uncorrelated with each other, and the inertia parameters are mutually independent, and correspondingly:
τ seneor ＝τ link +τ load 。
because the feedback data of the torque sensor is the combined action result of the connecting rods and the load, in order to reduce the calculation error of the torque theoretical value required by the movement of each connecting rod of the robot and improve the load identification precision, the inertial parameter set of the robot when the load is not added should be identified with high precision, and the dynamics model of the robot with high precision is obtained.
And after the inertial parameter set of the robot is corrected and the accuracy is improved when the load is not added, identifying the inertial parameter set of the load.
Correspondingly, the load torque
wherein For a dynamic model of the load with respect to the zero-space motion excitation trajectory, which is a coefficient term independent of the inertial parameter set of the load, phi load Is the inertial parameter set of the load.
When the robot moves in the zero space motion excitation track, a dynamic model of k groups of loads relative to the zero space motion excitation track and k groups of torque difference values are obtained according to a preset sampling period, and fitting values of inertial parameter sets of the loads can be obtained according to a least square method.
That is to say,
wherein ,a kinetic model of the excitation trajectory for the first set of loads with respect to the zero-space motion;for the k-th group of loads, a dynamic model of the excitation trajectory with respect to the zero-space motion, < >>For a first set of load torques; />The k-th group load torque, wherein k is an integer greater than or equal to 2.
Therefore, when the robot load is identified, the torque is directly read through the torque sensor at the connecting rod side, and the load is identified with high accuracy through calculation and pushing of other variables in an unordered manner. Moreover, in the robot load recognition process in the prior art, such as the chinese patent No. ZL201610967758.1, the feasibility of the excitation track needs to be checked, and if the operation of the excitation track can cause the collision between the robot load and the robot body, the excitation track needs to be re-optimized; however, in the present disclosure, by using the characteristics of the zero-space motion of the robot with seven axes or more, it is possible to ensure that the load is stationary with respect to the robot coordinate system during load identification, and avoid the risk during the actual running of the excitation track of the zero-space motion.
Moreover, the load can be identified more quickly and accurately through the optimized zero-space motion excitation track.
According to another aspect of the present disclosure, there is also provided an electronic device, including:
a memory storing execution instructions; and
and a processor executing the execution instructions stored in the memory, causing the processor to perform the method as described above.
According to another aspect of the present disclosure, there is also provided a readable storage medium having stored therein execution instructions which when executed by a processor are adapted to carry out the above-mentioned method.
In the description of the present specification, reference to the terms "one embodiment/manner," "some embodiments/manner," "example," "a particular example," "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment/manner or example is included in at least one embodiment/manner or example of the application. In this specification, the schematic representations of the above terms are not necessarily for the same embodiment/manner or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments/modes or examples. Furthermore, the various embodiments/modes or examples described in this specification and the features of the various embodiments/modes or examples can be combined and combined by persons skilled in the art without contradiction.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.
It will be appreciated by those skilled in the art that the above-described embodiments are merely for clarity of illustration of the disclosure, and are not intended to limit the scope of the disclosure. Other variations or modifications will be apparent to persons skilled in the art from the foregoing disclosure, and such variations or modifications are intended to be within the scope of the present disclosure.
Claims (12)
1. A method for identifying a load on a robot, comprising:
obtaining a dynamic model of the robot according to the structure of the robot;
generating a zero space motion excitation track;
obtaining a torque theoretical value required by the motion of the robot body according to a dynamic model of the robot and a zero-space motion excitation track of the robot;
after the robot is additionally provided with a load, the robot is operated to run a zero-space motion excitation track, and the actual torque value of each joint is acquired in real time; and
obtaining a torque difference value according to a torque theoretical value required by the motion of the robot body and actual torque values of all joints; obtaining an inertial parameter set of the load according to the torque difference value and a dynamic model about the zero-space motion excitation track;
wherein generating the zero-space motion excitation trajectory comprises: obtaining a zero space projection matrix of the robot according to the structural parameters of the robot; obtaining a zero space motion direction of the robot according to a zero space projection matrix of the robot; the zero space movement track data are obtained by planning the zero space movement speed; taking the characteristic of a regression matrix related to the zero-space motion trail data as an objective function, and optimizing the zero-space motion trail data; and obtaining the zero-space motion excitation track through the optimized value of the zero-space motion track data.
2. The robot load identification method of claim 1, wherein the set of load inertial parameters is obtained from a zero-space motion excitation trajectory.
3. The robot load recognition method of claim 1, wherein the joint includes a torque sensor for detecting an actual torque value of the joint drive link.
4. The robot load identification method of claim 1, wherein obtaining the inertial parameter set of the load from the torque difference and the kinetic model about the zero-space motion excitation trajectory comprises:
wherein ,the method comprises the steps that a dynamic model of a load about a zero-space motion excitation track is adopted, and phi load is an inertial parameter set of the load; τ load Torque required to drive the load motion; τ link The torque required to drive the motion of the link itself; τ sensor Is the torque sensor reading.
5. The robot load recognition method of claim 4, wherein the dynamic model of K groups of loads with respect to the zero-space motion excitation trajectory and K groups of torque differences are obtained according to a preset sampling period, and such that:
and obtaining an inertial parameter set of the load according to a least square method.
6. A robot load recognition device, comprising:
the dynamic model acquisition module is used for acquiring a dynamic model of the robot according to the structure of the robot;
the excitation track generation module is used for generating a zero-space motion excitation track;
the connecting rod torque calculation module is used for obtaining a torque theoretical value required by the robot body motion according to a dynamic model of the robot and a zero-space motion excitation track of the robot;
the load torque acquisition module is used for operating the robot to run a zero-space motion excitation track after the robot is additionally provided with a load, and acquiring actual torque values of all joints in real time through the load torque acquisition module; and
the load identification module is used for obtaining a torque difference value according to a torque theoretical value required by the movement of the robot body and actual torque values of all joints; obtaining an inertial parameter set of the load according to the torque difference value and a dynamic model about the zero-space motion excitation track;
wherein generating the zero-space motion excitation trajectory comprises: obtaining a zero space projection matrix of the robot according to the structural parameters of the robot; obtaining a zero space motion direction of the robot according to a zero space projection matrix of the robot; the zero space movement track data are obtained by planning the zero space movement speed; taking the characteristic of a regression matrix related to the zero-space motion trail data as an objective function, and optimizing the zero-space motion trail data; and obtaining the zero-space motion excitation track through the optimized value of the zero-space motion track data.
7. The robot load recognition device of claim 6, wherein the set of load inertial parameters is obtained from a zero-space motion excitation trajectory.
8. The robotic load recognition device of claim 6, wherein the joint includes a torque sensor for detecting an actual torque value of the joint drive link.
9. The robot load recognition device of claim 6, wherein,
obtaining the inertial parameter set of the load from the torque difference and the kinetic model about the zero-space motion excitation trajectory comprises:
wherein ,the method comprises the steps that a dynamic model of a load about a zero-space motion excitation track is adopted, and phi load is an inertial parameter set of the load; τ load Torque required to drive the load motion; τ link The torque required to drive the motion of the link itself; τ sensor Is the torque sensor reading.
10. The robot load recognition device of claim 9, wherein the K sets of load dynamics models with respect to the zero-space motion excitation trajectory and the K sets of torque differences are obtained according to a preset sampling period, and such that:
and obtaining an inertial parameter set of the load according to a least square method.
11. An electronic device, comprising:
a memory storing execution instructions; and
a processor executing the memory-stored execution instructions, causing the processor to perform the method of any one of claims 1 to 5.
12. A readable storage medium having stored therein execution instructions which when executed by a processor are adapted to carry out the method of any one of claims 1 to 5.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06190754A (en) * | 1991-04-26 | 1994-07-12 | Toshiba Corp | Identifying method for dynamic model of robot arm |
| US6069415A (en) * | 1998-06-05 | 2000-05-30 | Ati Industrial Automation, Inc. | Overload protection device |
| CN103495977A (en) * | 2013-09-29 | 2014-01-08 | 北京航空航天大学 | 6R-type industrial robot load identification method |
| CN106064377A (en) * | 2016-06-02 | 2016-11-02 | 西北工业大学 | A kind of excitation track optimizing method of robot for space dynamic parameters identification |
| CN106125548A (en) * | 2016-06-20 | 2016-11-16 | 珞石（北京）科技有限公司 | Industrial robot kinetic parameters discrimination method |
| CN106346477A (en) * | 2016-11-05 | 2017-01-25 | 上海新时达电气股份有限公司 | Method and module for distinguishing load of six-axis robot |
| CN106737656A (en) * | 2015-11-20 | 2017-05-31 | 沈阳新松机器人自动化股份有限公司 | A kind of robot load inertia recognition methods |
| CN107391861A (en) * | 2017-07-28 | 2017-11-24 | 珞石（山东）智能科技有限公司 | Industrial robot loading kinetics parameter identification method independent of body kinetic parameter |
| CN113146610A (en) * | 2020-12-08 | 2021-07-23 | 安徽工业大学 | Mechanical arm tail end track tracking algorithm based on zero space obstacle avoidance |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4256440B2 (en) * | 2007-08-10 | 2009-04-22 | ファナック株式会社 | Robot program adjustment device |
| JP2012081568A (en) * | 2010-10-14 | 2012-04-26 | Sony Corp | Device and method for controlling robot, and computer program |
-
2022
- 2022-01-10 CN CN202210021915.5A patent/CN114211502B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06190754A (en) * | 1991-04-26 | 1994-07-12 | Toshiba Corp | Identifying method for dynamic model of robot arm |
| US6069415A (en) * | 1998-06-05 | 2000-05-30 | Ati Industrial Automation, Inc. | Overload protection device |
| CN103495977A (en) * | 2013-09-29 | 2014-01-08 | 北京航空航天大学 | 6R-type industrial robot load identification method |
| CN106737656A (en) * | 2015-11-20 | 2017-05-31 | 沈阳新松机器人自动化股份有限公司 | A kind of robot load inertia recognition methods |
| CN106064377A (en) * | 2016-06-02 | 2016-11-02 | 西北工业大学 | A kind of excitation track optimizing method of robot for space dynamic parameters identification |
| CN106125548A (en) * | 2016-06-20 | 2016-11-16 | 珞石（北京）科技有限公司 | Industrial robot kinetic parameters discrimination method |
| CN106346477A (en) * | 2016-11-05 | 2017-01-25 | 上海新时达电气股份有限公司 | Method and module for distinguishing load of six-axis robot |
| CN107391861A (en) * | 2017-07-28 | 2017-11-24 | 珞石（山东）智能科技有限公司 | Industrial robot loading kinetics parameter identification method independent of body kinetic parameter |
| CN113146610A (en) * | 2020-12-08 | 2021-07-23 | 安徽工业大学 | Mechanical arm tail end track tracking algorithm based on zero space obstacle avoidance |
Non-Patent Citations (1)
| Title |
|---|
| 工业机器人负载动力学参数辨识方法;陈友东;胡澜晓;;机器人(03);全文 * |
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