Hardware Design And Implementation Of Gyrowheel Control System

With the development of aerospace technology and the diversification of aerospace missions,the application of microspacecrafts has become more and more widespread.To reduce the volume and quality on the premise of ensuring spacecraft performance has become a research hotspot.The gyro flywheel integrates sensors and The new attitude control element of the actuator has a broad application prospect.In this paper,according to the experimental research and application requirements of the gyro flywheel,the hardware part of the gyro flywheel control system is designed and implemented,including the current precision measurement module,the flywheel speed control drive module and the data acquisition communication module.First of all,this paper analyzes the working principle of the main hardware modules.Two precision current measurement methods,precision resistance sampling method and current/frequency conversion method,were proposed,and the main sources of error were analyzed.A phase-locked loop-based brushless DC motor control system was established.A phase-frequency phase-frequency discriminator with 10 states was designed to make the phase-locked loop controller closer to the linear link.The use of EtherCAT Industrial Ethernet bus to transfer data saves the real-time data communication while saving the ISA bus board.The hardware circuit of the current precision measurement system is designed and implemented.The precision resistance sampling method uses a resistor network to reduce the temperature drift of the sampling resistor,compensates the offset error through a self-calibration technique,and improves the current/frequency conversion method to increase the voltage of the integrated capacitor collected by the A/D converter,thereby improving the system measurement accuracy and resolution..Experiments show that the precision resistance measurement error is less than 1.5*10-4 amps and the current/frequency conversion method measurement error is less than 4*10-4 amps.Designed and implemented a flywheel drive hardware circuit.In addition to setting the circuit protection module in the software,the bus over-current protection,over-voltage protection,and pump-up voltage protection functions are additionally implemented through the hardware circuit,which ensures the reliability of the driving circuit operation.The experimental results show that the speed accuracy of the system is 0.04%,and the step signal and the ramp signal can be well tracked.Designed and implemented an EtherCAT-based data acquisition communication circuit.According to the system requirements,a data acquisition and output module composed of an analog switch,an A/D converter,and a D/A converter was designed,and a Nis II soft core was used to implement an EtherCAT slave in the FPGA.Analysis of the collected and output data proves that the communication syst em has real-time and reliability.