Development Of High Precision Motor Torque Fluctuation Measurement System

The gyroscope motor is the core component of high-precision equipment in inertial navigation and navigational control,torque fluctuation parameters such as the start-stop torque,load torque,and friction torque of the motor are important technical indicators of the motor,therefore,it is of great significance to achieve high-precision measurement of motor torque fluctuations.Aiming at the problem that the existing torque measurement equipment cannot meet the high-precision micro-torque measurement requirements of the gyroscope motor,this paper focuses on the key technologies of antiinterference structure design,signal processing,and static calibration.The torque sensor type,torque device and angle are developed.The sensor combines two highprecision measuring systems for torque fluctuations,and has completed experimental verification.The main work of the thesis is as follows:1.Aiming at the high-precision and high-stability index requirements of the torque fluctuation measurement system,a torque fluctuation measurement system scheme based on the coaxial transmission structure is designed,and the aerostatic bearing is used to reduce the friction interference torque;at the same time,in order to compare the measurement results,the torque sensor,the combination of torque sensor and angle sensor are used to achieve high-precision measurement of motor torque fluctuations.2.Aiming at the problem that the interference torque reduces the measurement accuracy,the anti-interference structure design scheme based on coaxial transmission and the flexible wiring method of hairspring are proposed.The elastic coupling is used to connect the shaft system to reduce the interference torque transmitted by the shaft system,the spring-like hairspring is used to optimize the external wiring structure and reduce the elastic interference torque introduced by the wiring;on the basis of the traditional weight calibration method,the chute type calibration rod structure is designed to reduce the uncertainty introduced by the length of the arm.Experimental results show that,compared with the system before optimization,the measurement accuracy of the system is improved by 90%,the uncertainty of static calibration is better than 0.025%,and the anti-interference ability is significantly enhanced.3.The torque ripple measurement system circuit is developed,the high signal-tonoise ratio,high anti-interference ability amplifier filter circuit are designed,realized the sensor’s weak signal high-precision conditioning;the system adopts the torque device to simulate the balance loop,designs the angle sensor modulation and demodulation circuit and the torque device current drive circuit,and realizes the highprecision measurement of the torque fluctuation signal.4.Two types of torque fluctuation measurement systems,torque sensor type,torque sensor and angle sensor combined type were developed,the software and hardware development of the measurement system were completed,and the static calibration and uncertainty analysis of the measurement system were carried out;the experimental results showed that the accuracy of the sensor-based torque ripple measurement system is better than 0.5%,and the drift error is better than 5μN·m/2h;the accuracy of the torque ripple measurement system combined with the torque sensor and the angle sensor is better than 0.1%,and the drift error is better than 0.5μN·m/2h.