| At present,the traveling wave ultrasonic motor with special hollow structure has the potential application duo to its excellent characteristics,such as low speed and high torque,quick response speed and good electromagnetic compatibility.The hollow structure of motor provided enough space for the signal line or the light path.Therefore,this kind of motor is widely used in the field of optics or medical instruments.However,there are many aspects to be improved,such as structure optimization,driving matching technology,non-linear problem,low speed stability control,production assembly stability control and so on.The key research contents of this paper include the following aspects: Optimization of stator and rotor structure of traveling wave type hollow ultrasonic motor,Motor drive voltage,Driving frequency,Matching point to the mechanical and electrical system performance and impedance characteristics,Mechanism of the phenomenon of the motor non-linear shutdown,Low speed stability control method of wave type hollow ultrasonic motor in control moment gyro,Optimization of the assembly process of the motor based on the special structure of the traveling wave type hollow ultrasonic motor.After research and analysis,this paper mainly obtains the following results and harvest.1?The characteristics of traveling wave type hollow ultrasonic motor and its application background are summarized.The current problems and research status of the traveling wave type ultrasonic motor are presented.The necessity of further research on the traveling wave type hollow ultrasonic motor is pointed out.2?The operating mechanism of the traveling wave type hollow ultrasonic motor is analyzed.The optimization design of the motor is optimized by the advanced design optimization theory.Through the optimization of the structure of the stator,the stator mode mixing and the small amplitude are optimized.Through the optimization of the structure of the rotor,the stiffness of rotor tends to rational with uniform contact interface between the stator and rotor.After optimization,the difference between the resonance frequency and the interference of the stator increased from 1 KHz to 2 KHz.This optimization also makes the stator amplitude increasing from less than 1.5 ?m to more than 3.5 ?m.The main goal of optimization measure contact uniformity from 0.27 before optimization for optimization of the1.48?10-5.3?The matching circuit of traveling wave type hollow ultrasonic motor is studied and analyzed.The optimum matching scheme of traveling wave type hollow ultrasonic motor is proposed.Combined with the motor body,a unified description of the mechanical and electrical integration system composed of motor and drive is described.The equivalent circuit of the whole mechanical and electrical integration system is obtained.Through the method of Fourier transform,the driving signal of ultrasonic motor is processed,and the calculation method of the motor and its drive system at all levels of efficiency is constructed.The performance test experiment of the parallel connection circuit of the traveling wave type hollow ultrasonic motor is carried out under different pre-stress,matching points and torque loads.Through the analysis of the experimental data,the admittance characteristics of the mechanical and electrical systems with different pre stress,matching points and torque load were analyzed and their effects on the performance of the motor were analyzed.Finally,the best drive frequency of the motor is larger than the frequency of the motor resonance frequency 100 Hz ~ 200 Hz.4?Three kinds of non-linear phenomena of the current traveling wave type ultrasonic motor are described.Focus on the traveling wave type hollow ultrasonic motor in a certain torque load conditions will appear under the sudden stop and the load unload after motor cannot rotate the phenomenon.Through the theoretical analysis of the forced vibration of ultrasonic motor stator,the nonlinear mechanism of the ultrasonic motor probably results in the load torque increase which leads to the increase of the resonance frequency of the motor.The reason of the increase of the resonance frequency of the motor is that the load leads to the decrease of the damping ratio of the stator.Finally,the frequency modulation test results at different load torque verify that the load causes the motor resonance frequency increase.5?In order to simulate the control moment gyroscope driven by traveling wave type hollow ultrasonic motor,the control algorithm based on fuzzy T-S model is used to simulate the speed stability of the motor,and the speed tracking error <0.2 °/s is obtained.Finally,the control moment gyroscope platform and at 0.005 °/s~72 °/s within the speed range of the motor speed is stable and fixed angle locking precision test.The experimental results are obtained when the motor speed is greater than 0.1°/s,the fluctuation is less than 5%.When the speed is less than 0.1°/s,the fluctuation is less than 0.01 °/s.The absolute fixed angle locking error is less than 2 arc-second,and the relative fixed angle locking error is less than 1%.The experimental results show that the control algorithm based on the fuzzy T-S model is more accurate than the traditional PID control algorithm,and the control precision of the motor speed stability is higher.6?For piezoelectric ceramic bonding process design pressure out of a bonding pressure of piezoelectric ceramic sheet tooling to overcome the piezoelectric ceramic wafer bonding process of adhesive layer is too thick and the air bubble.The stator assembly and the base of the traveling wave type ultrasonic motor are studied.Different installation methods ultimately determine the thread loop pressure installation method,which is the most suitable means for traveling wave type hollow ultrasonic motor.The methods of applying and maintaining different pre pressure of ultrasonic motor are studied,and the method of applying pre pressure to the thread is determined.The traveling wave type ultrasonic motor involves a set of pre pressure design installment to ensure that the pre pressure of the motor can be accurately applied with about 5N error. |
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