CMOS Star Sensor System Design

Star sensor is a kind of high precision optic sensor widely used for attitude determination in spacecrafts, secondary planet, long-distance guided missile, cruise missile and other space attitude measurement.This paper background of a real project development, discuss a CMOS Star Sensor system design which can be used on moonlet and other spacecrafts as embedded attitude determination device. This system use a CMOS image sensor STAR250 to get image of stars. CPLD for device driver and preprocess, and make the ARM9 processor as host MCU. The ARM9 processor use stars matching arithmetic and other software methods to get the attitude information and translate it to the center controller of spacecraft.The main job of project research is system design for the sample CMOS star sensor, driver design for STAR250, and use CPLD implement preprocess of the star image. AS a attitude determine device on secondary planet, it has relative strict requirement. ARM series processor has many profits of low power, low consume, high integration and expansibility very suit for space usage. On the other hand, more than 200MHz frequency guarantee the real time process of stars image. STAR250 as a CMOS image sensor don't support IIC and other standard interface, So we use an Altera 10,000 gates CPLD implement device driver of STAR250 as well as preprocess of stars image and interface to processor system. Throw modularization program and provide host interface to ARM make the system more flexibility and maneuverability.At last, via experiment and analysis star image, this embedded CMOS star sensor device has benefits of high precision, miniaturization, low cost and low power, and very suit for space usage.