Performance Diagnosis Of The Drive Unit For High Speed Motorized Spindle Based On Hidden State Mapping Model

High-speed CNC machine tools are the basic equipment of the equipment manufacturing industry,high-speed motorized spindle is one of the core functional components,and plays an important role in the Machining efficiency and accuracy.Motorized spindle driver is used as a high-speed motorized spindle driven power source,which can control the running performance.High-speed motorized spindle driven system will inevitably suffer performance degradation during operation,in order to ensure safety and reduce economic losses caused by accidents,the system performance is monitored regularly,the system is made a system maintenance plan,according to the current performance status.Due to the control system feedback link,it is impossible to monitor the system performance only through the system output,and the control system performance monitoring is still a difficult field.The thesis is aimed at the evaluation of the control system implicit degradation performance,a control system performance evaluation method based on implicit degradation is proposed,and used in high-speed motorized spindle drive system,the thesis includes the following aspects:(1)The frequency converter serves as a high speed motorized spindle driver,the working process has an impact on the motorized spindle performance,the performance is constantly degradation.First,IGBT on the insulation performance of the motorized spindle is analyzed,IGBT work will make the insulation performance of the motorized spindle continue to degrade.The mechanism of the component IGBT is analyzed,which includes IGBT chip structure and working principle.Finally,the IGBT degradation failure mechanism is analyzed,reconstruction of aluminum metal layer and bonding wire fall off belong to cumulative degradation.The internal on-resistance keeps increasing with the degradation of the IGBT.(2)The drive system performance evaluation index is establishmented.For high-speed motorized spindle drive systems,the degradation process is implicit cumulative degradation,first,the closed-loop system ARX model is introduced.The extraction steps of the implicit degradation characteristic value and the establishment method of evaluation index are described.Under different working conditions and environments,the system identification method is used to identify the motorized spindle driven system model,the best estimated parameter value of the model is obtained,that is,the performance implicit degradation characteristic value.Finally,the normal state characteristic parameter vector is the reference vector,the Euclidean distance between the characteristic parameter vector of the degradation state and the reference vector is used as the evaluation index.That is,the implicit degradation amount.(3)Experimental design verification.The vector control simulation model of high-speed motorized spindle is built by Matlab,IGBT performance degradation process is simulated,the feature parameter vector was extracted by parameter identification,and the performance evaluation index was established by distance method.The influencing factors of performance evaluation index is analyzed,the application of the performance evaluation method in the driving simulation system of high-speed motorized spindle is verified;through the laboratory platform,this thesis does IGBT accelerate the degradation experiment,and verifies the correctness of the regular that the internal on-resistance value gradually increases;the accelerated degradation experiment of IGBT was carried out on the motorized spindle experimental platform,the feasibility of using the performance evaluation method based on the implied degradation in the drive system of high-speed motorized spindle is verified.In summary,the two cumulative degradation phenomena of IGBT are bond wire fracture and aluminum metal layer reconstruction,conductive resistance value increases gradually with performance degradation;the thesis presents a control system performance evaluation method based on implicit degradation,the feasibility of the performance evaluation method was verified by experiments in the motorized spindle driven system.