Error Measurement And High-speed Motion Algorithm Optimization Design For Five-axis Dispensing Machine

In today's era of digitalization and rapid development of information technology,"Internet+" technology is popular all over the world,the combination of microelectronics technology and Internet technology has become the focus of development of many industries,making the development of electronic products gradually towards miniaturization and precision,which also promotes the progress of electronic product assembly process,dispensing machine in the electronic product Surface mount plays a very important role.Compared with the foreign mature automatic dispensing equipment,China's dispensing machine both in the dispensing precision or dispensing speed have a big gap.Dispensing machine in the process of dispensing processing will produce a variety of errors,including mainly with the machine tool components in the process of movement due to their own and load dynamic characteristics of the error,called dynamic error,the machine tool dynamic error is the greatest impact is the system of rotational inertia;another error called static error,mainly refers to the machine bed and its parts in the manufacturing,assembly process geometry error.In this paper,the five-axis double rotary table dispensing machine of a company(hereinafter referred to as L company)is used as the research object,focusing on the error measurement of the five-axis dispensing machine and the optimization design of the high-speed motion control algorithm.The error measurement includes dynamic error measurement and static error measurement.The dynamic error measurement mainly refers to the identification of the rotational inertia of the servo motor axis and the self-tuning of the controller parameters during the motion of each axis of the machine;the static error measurement adopts the double-ball rod instrument to identify the error of each axis of the machine and then make compensation.The above operation is mainly to improve the dispensing accuracy of the dispensing machine.In the high-speed dispensing system,a control algorithm of S-curve lifting speed is designed and optimized to speed up the dispensing speed while ensuring the smoothness of processing,so that the control performance of the control system is also well improved.The research mainly includes the following parts.(1)In order to detect the dynamic error of the machine tool in motion control,the simulation of permanent magnet synchronous motor rotational inertia is identified.The permanent magnet synchronous motor(PMSM),which provides power in the fiveaxis dispensing machine,is used as the object of study.The study focuses on the rotational inertia,which is the most influential factor on the dynamic characteristics of the machine.A mathematical model of the three-phase PMSM is established,a simulation model of the vector control of the three-phase PMSM based on PI controller is built in MATLAB\Simulink,and simulation experiments are conducted to identify the rotational inertia of the three-phase PMSM with the model reference adaptive identification algorithm.(2)In order to reduce the static error of the dispensing machine,the accuracy inspection method of CNC machine tool based on ballbar is studied and applied to the five-axis dispensing machine of Lechon.The structure of the machine tool is analyzed,and the errors causing the machine tool processing are systematically classified according to whether the errors are position-related or not.The dynamic and static geometric errors of the machine tool are defined,and the mathematical model of the five-axis dispensing machine and the spatial error model are established by the method of flush transformation matrix.Based on the company's five-axis dispensing machine,a ballbar tooling and geometric error measurement scheme is designed,and the static geometric errors of the machine tool are identified using the QC20-W ballbar.(3)Two common speed-up and down control algorithms,T-shaped and S-shaped in CNC machining,were analyzed to obtain three possible cases of T-shaped curve speed-up and down and eight possible cases of S-shaped curve speed-up and down,respectively,and were designed and calculated to obtain their theoretical interpolation times.Then,based on MPC8801 motion control card,this algorithm was implemented and the efficiency of L's I5 series controller was calibrated.Finally,the effects of two different lifting and lowering modes,T-shaped and S-shaped,on the motion control accuracy are experimentally compared.