CN-122008219-A - Clamping error identification method for precise assembly and electronic equipment

CN122008219ACN 122008219 ACN122008219 ACN 122008219ACN-122008219-A

Abstract

The invention relates to a clamping error identification method for precise assembly and an electronic device, the method comprises the steps of firstly constructing an assembly system model and initializing a force sensing module, and identifying a clamping position error and carrying out gravity compensation by analyzing the mapping relation between force sensing data and the barycenter coordinates of a part when the part is clamped; and finally, the robot performs real-time motion compensation under an impedance control strategy based on the identified position and the identified attitude error, and evaluates the assembly quality after assembly until all parts in the batch are assembled. According to the invention, the on-line dynamic identification and closed-loop correction of the position and posture deviation in the clamping process are realized through the force sensing information, and the assembly precision and the system self-adaption capability are obviously improved.

Inventors

ZHANG XIANMIN
WANG ZIXIANG
ZENG JIAHAO

Assignees

华南理工大学

Dates

Publication Date: 20260512
Application Date: 20260313

Claims (10)

1. The clamping error identification method for precision assembly is characterized by comprising the following steps of: s1, constructing an assembly system model, and initializing a force sensing module in the assembly system model; S2, the assembly robot clamps the first assembly object through the clamping module, and the force sensing module acquires force sensing data containing gravity information of the clamping module and the first assembly object; S3, enabling the first assembly object to be in contact with the identification reference object, and identifying the clamping posture error based on the force sensing data after the gravity compensation; and S4, compensating the clamping motion of the robot based on the identified clamping position error and the clamping posture error so as to realize the assembly with the second assembly object under the impedance control strategy.
2. The method for identifying clamping errors for precision assembly according to claim 1, wherein step S2 specifically comprises: s21, establishing a mapping relation among barycentric coordinates, gravity and force sensing data of the first assembly object; S22, solving the coordinate of the gravity center under the coordinate system of the force sensing module according to the mapping relation, and comparing the coordinate with the expected position to obtain a clamping position error; s23, carrying out gravity compensation on the first assembly object according to the barycentric coordinates and the gravity.
3. The method for recognizing clamping errors for precision assembly according to claim 2, wherein the mapping relationship in step S21 is: ; ; In the formula, For the first assembling object gravity center At a location in the force sensing module coordinate system, For the moment information obtained by the force sensing module, For the force information obtained by the force sensing module, For the first assembly object to be gravity-fed, Is a gesture transformation matrix from a world coordinate system to a force sensing module coordinate system.
4. The method for recognizing a clamping error for precision assembling according to claim 2, wherein the gravity compensation formula for the first assembling object in step S23 is: ; ; ; In the formula, For the data result after the gravity compensation of the first assembly object, For the force/moment component of the first assembly object gravity to the force sensing module, the gravity center can be used for Coordinates and gravity Obtaining the product.
5. The method for identifying clamping errors for precision assembly according to claim 1, wherein step S3 specifically comprises: S31, constructing a force line equation of the contact resultant force under a force sensing module coordinate system, combining the force line equation with a preset upper end surface curve equation and a curved surface equation of the identification reference object, and solving to obtain the coordinate of the contact point under the force sensing module coordinate system; S32, obtaining coordinates of a plurality of contact points through multiple contact, fitting according to the coordinates of the plurality of contact points to obtain an attitude vector of the first assembly object, and comparing the attitude vector with an expected attitude to obtain a clamping attitude error.
6. The method for recognizing clamping errors for precision assembling according to claim 5, wherein in step S31, a world coordinate system is determined Upper end surface curve of lower identification reference object And curved surface : ; ; In the formula, Radius of reference axis, point In a world coordinate system for the center point of the circle of the upper end face of the reference shaft Coordinates of (c); from force-sensing module coordinate system kinematically available by assembly robot To the world coordinate system The transformation matrix of (a) is: ; In the formula, In order to transform the matrix for the gesture, Is a position transformation matrix; Further, a curve can be obtained And curved surface In the coordinate system of the force sensing module The following expression is: ; ; In the formula, Subscript for the coordinates of any point in the force sensing module coordinate system Representing taking only the first two components of the vector, Representing taking only the last component of the vector.
7. The method for recognizing a clamping error for precision assembly according to claim 5, wherein in step S31, constructing a force line equation and solving coordinates of a contact point comprises: under the coordinate system of the force sensing module, the linear equation of the contact resultant force is ; ; In the formula, As a straight line equation where the contact resultant force through the contact point is located, Is a straight line equation parameter; The linear equation is respectively combined with an upper end surface curve equation and a curved surface equation for identifying the reference object, so that different solutions can be obtained Value of 、 By comparing the two sizes, a straight line can be judged The contact point homogeneous coordinates under the coordinate system of the force sensing module are obtained by the successively passing parts 。
8. The method according to claim 5, wherein in step S32, the first assembly object is contacted with the identification reference object a plurality of times to obtain coordinates of a plurality of contact points, and the result of solving the posture vector is: ; ; ; In the formula, For a matrix of a plurality of contact point coordinates, Is a unit vector.
9. The method for identifying clamping errors for precise assembly according to claim 1, further comprising the step of S5, performing assembly quality assessment on the assembled part, including critical fit dimension assessment, assembly process force curve assessment and/or visual inspection of the part surface, and if the quality meets the requirements, repeating the steps of S2 to S4 for assembling the next part, otherwise recovering the current part.
10. An electronic device comprising a processor and a memory, wherein the memory stores a computer program, and wherein the processor implements the clamping error recognition method for precision assembly according to any one of claims 1-9 when executing the computer program.

Description

Clamping error identification method for precise assembly and electronic equipment Technical Field The invention relates to the technical field of precision assembly, in particular to a clamping error identification method for precision assembly and electronic equipment. Background Precision assembly is a key link in high-end manufacturing, and the assembly precision directly determines the final quality and performance of the product. During assembly, the robot is required to reliably grip the parts and perform precise movements. However, in actual operation, there is often a slight deviation between the gripping posture and the position of the robot due to factors such as part feeding deviation, jig wear, positioning error of the robot, and the like. If the deviations can not be identified and corrected in time, the parts are dislocated, stuck or collided during matching, and the assembly success rate and the product consistency are seriously affected. At present, a common robot assembly system is controlled by mostly depending on teaching positions or visual positioning, and lacks of real-time and direct perception of clamping states. Particularly, in the process of contact or stress, the small force and moment change caused by the incorrect clamping posture or position deviation is difficult to effectively identify only by the position closed loop. The existing method generally assumes ideal clamping state, once deviation occurs, the system is often not automatically perceived until abnormal or failed assembly is discovered, so that the production efficiency is reduced, and the damage risk of equipment and parts is increased. Disclosure of Invention Aiming at the problems in the prior art, the invention aims to provide a clamping error identification method for precise assembly and electronic equipment, which can accurately identify clamping position errors and clamping posture errors in real time and provide basis for subsequent correction and self-adaptive control. In order to achieve the above purpose, the invention adopts the following technical scheme: A clamping error identification method for precision assembly comprises the following steps: s1, constructing an assembly system model, and initializing a force sensing module in the assembly system model; S2, the assembly robot clamps the first assembly object through the clamping module, and the force sensing module acquires force sensing data containing gravity information of the clamping module and the first assembly object; S3, enabling the first assembly object to be in contact with the identification reference object, and identifying the clamping posture error based on the force sensing data after the gravity compensation; and S4, compensating the clamping motion of the robot based on the identified clamping position error and the clamping posture error so as to realize the assembly with the second assembly object under the impedance control strategy. Further, step S2 specifically includes: s21, establishing a mapping relation among barycentric coordinates, gravity and force sensing data of the first assembly object; S22, solving the coordinate of the gravity center under the coordinate system of the force sensing module according to the mapping relation, and comparing the coordinate with the expected position to obtain a clamping position error; s23, carrying out gravity compensation on the first assembly object according to the barycentric coordinates and the gravity. Further, the mapping relationship in step S21 is: ; ; In the formula, For the first assembling object gravity centerAt a location in the force sensing module coordinate system,For the moment information obtained by the force sensing module,For the force information obtained by the force sensing module,For the first assembly object to be gravity-fed,Is a gesture transformation matrix from a world coordinate system to a force sensing module coordinate system. Further, the gravity compensation formula for the first assembly object in step S23 is: ; ; ; In the formula, For the data result after the gravity compensation of the first assembly object,For the force/moment component of the first assembly object gravity to the force sensing module, the gravity center can be used forCoordinates and gravityObtaining the product. Further, the step S3 specifically includes: S31, constructing a force line equation of the contact resultant force under a force sensing module coordinate system, combining the force line equation with a preset upper end surface curve equation and a curved surface equation of the identification reference object, and solving to obtain the coordinate of the contact point under the force sensing module coordinate system; S32, obtaining coordinates of a plurality of contact points through multiple contact, fitting according to the coordinates of the plurality of contact points to obtain an attitude vector of the first assembly object, and comparing the attitude vector