Research On The Characteristics Of Electro-magnetic Micro-actuator Based On Halbach Permanent

In recent years, rapid development of the technology of precision positioning asks electromagnetic micro-actuators to satisfy the require of measuring long-range displacement with high accuracy. This thesis is based on the " The electromagnetic servo driving method and dynamic characteristics of local adjustable magnetic field "(Project of NSFC, No.51005213).A novel electromagnetic micro-actuator based on the local adjustable magnetic field is proposed. Through comparison of theoretical analysis, finite element analysis and experimental results,feasibility of electromagnetic micro-actuator design is proved and the electromagnetic characteristics are analyzed.Secondly, the3-D method of FEA is applied to build the parametric model of permanent magnet matrix already known all over the world. The effective magnetic field distribution were compared and a new structure based on Halb ach permanent magnet array is put forward aiming at the electromagnetic peculiar armature structure of electromagnetic micro-actuator. The results indicate the working characteristics of the micro-actuator are effectively improved.Finally, the production of prototype and construction on measurement system are completed. The data of actual measured value and theoretical value are compared with each other. The theoretical value of horizontal magnetic field for the array is7%more than measured value at2mm height of the air gap, while the theoretical value of horizontal magnetic field for the array is8%less than the measured value, the two magnetic density curve are consistent. A work platform for suspending experiment is built and suspending experiment of electromagnetic micro-actuator is finished under different value of current. The characteristic curve of the relationship between air gap and wire array current is drawn and compared with the curve got from FEA. The conclusion is brought that the average error of the input current is39mA, while the standard deviation is56mA, the curves of the experimental result and FEA fit good with each other, so the validity of design and theoretical method is verified.