Research On The Linear Variable Reluctance Resolver

With the advancement of science and industrial development,sensors have played an increasingly important role.They have been widely used in education,industry,medical care,and military affairs.In the field of linear displacement sensors,linear displacement sensors such as grating scales and magnetic scales have the advantages of high accuracy,fast response,quick installation,and large range,and have been widely used.Linear displacement sensors are also constantly moving in the direction of higher precision and more intelligence.However,in some cases where the the requirement of accuracy is not high,and the strict cost reduction are required,there is still a practical need for a linear displacement sensor with a lower cost.The variable reluctance resolver is the sensor of position and speed of a motor that is primarily used in rotary motor servo systems.Compared with other types of sensors,its simple structure,low cost,low process requirements,and strong anti-interference ability are its greatest advantages.The linear resolver obtained from the linearization of the traditional resolver is a new type of linear sensor.Compared with other conventional linear displacement sensors,its structure is simpler,its cost advantage is more significant,and it has broad development prospects.Firstly,considering the structural characteristics of resolver and the subsequent linearization process,an analytical magnetic model of the resolver is established in this paper based on the equivalent magnetic circuit method,and the slot matching and winding topology of the conventional resolver are analyzed.A simplified rotor structure was proposed and harmonic analysis was performed,which proved the feasibility of the rotor structure.At the same time,considering the high-order harmonics of the air-gap conductance introduced by the rotor structure,its influence on the output signal of the resolver is analyzed in detail and a rigorous mathematical proof is given.Mathematical analysis shows that only specific higher harmonics have an adverse effect on the output signal.Secondly,this dissertation analyzes the four side effects in detail for the structural characteristics of linear resolver,and proposes an equivalent magnetic circuit model that introduces the side-effect of the linear motor.In order to reduce the influence of the end effect,this paper proposes an optimized scheme of moving edge teeth.In addition,the linear revolving model is built on the finite element analysis software,and the position,shape and secondary contours of the side teeth are optimized in order to effectively eliminate the function error introduced by the edge effect of the linear motor.Finally,the prototype of the linear resolver was built in this paper,a hardware test platform was set up,and a signal processing program was written.Through the test ofthe experimental prototype,the actual waveform and error curve of the linear revolving output signal were obtained,and the influence of the process error on the output signal and error of the linear resolver was analyzed.The corresponding error curve was calculated by the finite element analysis method.The experimental results are in accordance with the theoretical analysis and simulation,verifying the correctness and feasibility of the linear resolver.