EKF implementation on S3CEV40 for InnoSAT attitude determination system

Extended Kalman Filter (EKF) has been successfully utilized in a number of satellites. However, compared to other attitude determination methods developed, it is one of the most computationally burdening algorithm and with the new trend of using nano-satellites which have limited electrical power, mass, space and usually budget, it is essential to design an attitude determination system (ADS) which conforms to this limitation. Therefore, in this paper, as an improvement on the InnoSAT project which incorrectly runs the EKF algorithm on the RCM3400, the CPU is replaced with the ARM7TDMI microprocessor to successfully perform attitude determination of InnoSAT using the EKF. The ARM7TDMI has been chosen since it is one of the well-known microprocessor used in various electronic equipment because it is low power and robust. It is also off the shelf which means it is easily available thus making it a cheaper solution than a space grade component. Analysis on the ARM7TDMI was done based on attitude data accuracy and execution time.