| Inertial navigation has a wide range of applications in aerospace,aviation,and navigation.The accuracy of inertial navigation is subject to the accuracy of inertial instruments.With the improvement of the accuracy requirements of inertial instruments,the demand for high-precision inertial instrument test equipment is becoming more and more urgent.The angle vibration table is a high-precision test equipment for dynamic performance testing of inertial instruments and inertial systems.Its output needs to meet the characteristics of high reliability,high precision and frequency bandwidth.In order to simulate various vibrations in the environment as the input of the inertial instrument,measure the dynamic characteristics of the inertial instrument and establish a dynamic model to realize error compensation and improve the performance of the inertial instrument.The angular vibration table for this purpose requires high-precision static rate signal and high output.Accuracy sinusoidal vibration signal needs to solve the problem of rate fluctuation caused by torque fluctuation,amplitude attenuation of vibration process,phase lag,waveform distortion caused by friction,and control system requires high sampling frequency and other technical problems.In this paper,the vector control method of synchronous motor is analyzed.The dynamic model of the motor is established.The transmission characteristics of torque fluctuation are analyzed.The mechanism of gear cogging torque fluctuation and electromagnetic torque fluctuation is studied.The cogging torque is electromagnetic.The Z-order harmonic of the moment,the electromagnetic torque fluctuation is mainly the Porder and 2nP-order harmonics,especially the conclusion of the 6P-order harmonic.Therefore,an algorithm for IQ decomposition of the fluctuating torque and reconstruction of the torque fluctuation is proposed.The simulation verified that the rate fluctuation caused by the torque fluctuation after compensation was reduced to 4% before compensation.The difficulty of the sinusoidal vibration process is divided into two parts.One is the phase lag of the high frequency vibration process and the amplitude attenuation.A four closed loop controller is proposed to close the desired signal,eliminating the amplitude attenuation and phase lag.Secondly,based on the Stribeck model,the influence of friction torque on waveform distortion under low frequency vibration is studied.The repeated learning controller is designed.The sinusoidal vibration has the characteristics of periodicity under the sinusoidal vibration.The output converges to the desired sinusoidal waveform,suppressing the effects of frictional moments.Finally,the control effect of the four closed-loop controller and the repetitive learning controller is verified by simulation,and the sinusoidal vibration of 0.1Hz to 100 Hz is realized.For the angular vibration table,which needs real-time control and high sampling frequency,the embedded motion control board of FPGA+DSP structure is designed.The control algorithm is implemented in the DSP,and the data is collected,forwarded and Synchronization of the inertial system.Finally,experiments were carried out on the existing single-axis turntable to verify the control performance of the four closed-loop controllers and the repetitive learning controller. |
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