| Planar switched reluctance motor(PSRM)has been attractive increasing attention in the precise positioning application such as circuit manufacturing,precision machining,and biomedical engineering.Accurate mover position is important for a PSRM to achieve reliable operation and precision positioning.The position mover position is generally detected by the position sensor,such as optical encoder and magnetic encoder.However,these position sensors is relatively expensive and susceptible to influence from harsh environments,such as high temperatures,dust,and damp.Thus,a PSRM system utilizing these position sensors will have the disadvantages of high cost and low reliability.This thesis proposes an assistant-mover-based position sensorless estimation and control method for PSRM.First,the PSRM with assistant movers is introduced in this thesis.The structure of PSRM with assistant mover is described,the principle of mover position estimation based on assistant mover is presented,and the model of PSRM control system with assistant mover is derived.Then,the assistant mover is analyzed and designed.The design requirements of the assistant mover are given.An analytic model of the flux density of the assistant additional mover is developed using equivalent magnetic circuit method,and parameter of assistant mover is determined based the analytic model of the flux density.Based on the determined parameter,the assistant mover is analyzed by using the finite element method.The assistant mover is manufactured and the flux density measurement experiment is performed.The experimental results show that: 1)the relative error of analytic model of the flux density is less than 8.9%,which verify the effectiveness of the analytic model of the flux density.2)The designed assistant mover can meet the design requirements.Furthermore,the assistant-mover-based position estimation method is investigated.A position estimation algorithm is proposed,which is not required previous experimental data regarding the position and Hall sensor output signals.The position estimation algorithm has the advantages of easy implement,simple calculation and small memory occupation.The proposed position estimation algorithm requires balanced Hall sensor output signals.However,the Hall sensor output signals would be unbalanced in practice.Thus,the influence of unbalanced hall sensor output signal is analyzed and a compensation scheme is proposed.The position estimation experiment is performed,and the influence of different operating speeds on of the position estimation accuracy is analyzed,experimentally.The primary experimental results are presented as follows: 1)The fast operating speed of the PSRM will cause the distortion of the Hall sensor output signals and the position estimation error;2)When the PSRM operates at the speed of 1 mm/s,the position estimation error of the x-axis is less than 0.16 mm.and the position error of y-axis is less than 0.14 mm.The effectiveness of the proposed position estimation method is verify experimentally.Finally,the assistant-mover-based the position sensorless control is studied.The proportional differential(PD)position controller is designed using linear system frequency domain correction method;Combining the PD position controller and position estimation method,the position sensorless control experiment is performed.The main experimental results include following: 1)The static error of x-axis the is less than 0.61 mm,and the dynamic error is less than 1.15 mm;2)The static error of y-axis is less than 0.70 mm,and the dynamic error is less than 1.32 mm;3)For two-dimensional motion,the dynamic errors of x-axis and y-axis are less than 2.14 and 2.10 mm,respectively.The effectiveness of the proposed position sensorless control method is verified experimentally. |
PDF Full Text Request