Research On The Precision Compensation Of Modular Reconfigurable Robots Based On Inter-module Errors Decoupling By Measurement

Modular reconfigurable robots,by changing the mechanism configuration base on different structure environments,can adapt to variable working-environments.The characteristic of modular reconfigurable robots very meets the modern requirements with the flexible productive ability and solving mutilate tasks in structure environments or not.However modular reconfigurable robots face the hinders of low absolute positioning precision,and can't put it to actual works immediately.As mentioned above,the research of this paper focus on the calibration,and relative works,of modular robots after reconfigured.The subject is relying on “Research on the precision compensation of modular reconfigurable robot based on inter-module error decoupling”,with the support of the National Natural Science Fund Project of China.The main research contents include the following aspects:Automatically generate the kinematics model for modular reconfigurable robots.The paper has discussed several common robotic modeling methods,the theoretical basis of various modeling methods,and compared the advantages and disadvantages among different methods.The point of methods of the paper is local POE model,obtaining the kinematics model automatically.Finally,programming software is used to code the program of automatic generation of the kinematics equation.The study on the measurement,identification and precision compensation of connectors assembly error in the joint-link.The geometrical parameters of a single joint and link of a reconfigurable robot can achieve high numerical accuracy by offline measurement,but after assembly of joints and links,the errors caused by assembly cannot be identified by offline measurement.To solve the problem of assembly errors measurement and identification,a measurement method is designed.Based on this measurement method,a pair of mechanical connectors is designed on the consecutive joints and links,and the geometric relation formed by the mechanical connectors realizes the errors measurement and recognition.In addition,the paired mechanical connectors can meet the requirements of the modular reconfigurable robot for repeated and rapid reloading.Finally,the programming software is used to code the processing program of assembly errors measurement and recognition.Verification experiment of single pairing joint-link.Based on the assembly errors measurement method,a single joint and link for the experiment are designed,and the pairing mechanical connectors are integrated into the joint and link to form the joint-link pairs.Through the physical experiment of joint-link pairs,the validity of the assembly errors measurement method and the correctness of assembly errors processing program are verified.Research on precision compensation of reconfigurable manipulator based on module ontology errors offline measurement and assembly errors real time on-line measurement.The errors of the modular reconfigurable manipulator are divided into dynamics variable errors and fixed parameter errors of mechanical structure,and the errors model of the end position of the manipulator is established.Based on the previous work,the connector is integrated into all joints and links to form joint-link pairs,and the assembly errors at all connectors are obtained by on-line measurement,and the geometrical parameters of a single joint and link are measured offline,thus solving the problem of fixed parameter errors compensation of the whole reconfigurable manipulator.The existing joint variable errors(dynamics variable errors)are also compensated by offline measurement.Finally,the errors model of reconfigurable manipulator is simulated and analyzed,and the validity of the error compensation method and the stability of the algorithm are verified.