Modification of the Azimuth Control System in the LLMC

The original azimuth transmission mechanism in the LLMC causes too much vibration during the transpotation of the horizontal axis of the inst rument.In order to solve the problem, a new plan is presented in this paper, which is to replace the original stepper motors with a new type of stepper motor.Therefore the hardw are structure of the original control system must be modified .The hardware architecture of the new system is described .The ASM control program in the single chip microcontroller is rew ritten , which is composed of 10 subroutines.The methods used in cont rolling motors and skills in designing the program are presented in the paper.