Design And Experimental Research Of A Position And Posture Driving System Of The Primary Mirror For A Ring Solar Telescope Based On CAN Bus

Aiming at the problems of multiple harnesses,poor real-time performance and inflexible control of the primary mirror’s position and posture driving system of the 2-meter ring solar telescope,this thesis designs a set of position and posture driving system of the primary mirror based on CAN bus communication technology,which improves the stability and real-time performance of the driving system.Comprehensive tests and researches were conducted on the axial support prototype of the primary mirror to evaluate of its performance which can meet the driving targets.The specific work is as follows:(1)A new type of position and posture driving system architecture for the primary mirror of the ring solar telescope based on CAN bus communication technology is proposed.According to the index of the primary mirror’s posture drive,the kinematic analysis of the primary mirror is carried out to obtain the control index of the displacement actuator.In line with the control index of the displacement actuator and the requirement of reducing the harness of the position and posture driving system of the primary mirror,a distributed driving system is established.(2)The hardware and software design of the driving system of the primary mirror of the ring solar telescope based on CAN bus is completed,and the system platform is built.The hardware design includes the design of master node and child node.The master node part takes STM32F407VET6 as the core to design the hardware circuit from Ethernet to CAN.It communicates with upper computer through Ethernet while transmitting tasks to the corresponding child node by the CAN bus to complete the coordination work of each node;STM32F103C8T6 is used in the microcontroller of the child node part to collect data from the sensor,control the stepper motor,and transmit data based on CAN communication as well.In addition,according to the actual requirements of software functions,the host computer software is designed to realize the functions of communication network connection,motor control,real-time display,data storage and so on.The slave computer software including CAN communication,motor control,AD sampling and interrupt nesting is developed.Finally,the platform of the driving system of the primary mirror is built.(3)The experimental research on the position and posture driving system of the primary mirror is carried out.Firstly,test the performance of single displacement actuator and analyse the experimental results.The results show that the performance of the displacement actuator can meet the design requirements.Then,the performance of the driving system is tested with the help of laser displacement sensor and inclinometer.The error of the system is analyzed and corrected to meet the requirements of the design targets.The results show that the steady-state error of the rotation angle in the X-axis direction and the rotation angle in the Y-axis direction of the driving system is better than 1″,and the steady-state error in the Z-axis direction is better than 1 μm,which meet the design requirements.Finally,the primary mirror is tested under load.The results show that the driving system based on CAN bus can still drive the position and posture of the primary mirror effectively,and can meet the requirements of the design.From the above work,it can be seen that the position and posture driving system of the primary mirror proposed in this thesis can provide significant technical support for the construction of 2-meter ring solar telescope and provide reference for the engineering application of other precision optical mirror driving systems.