On Real Time Performance Evaluation of the Inertial Sensors for INS/GPS Integrated Systems

In this paper, a new performance evaluation method is proposed for the inertial navigation system (INS) aided by the global positioning system (GPS). Inertial sensors in the INS are the key components for motion measurement. However, they are vulnerable to external disturbances, and performance degradation is likely to happen. Thus, a performance evaluation method is essential for real-time monitoring of motion measurement. On the other hand, conventional evaluation methods are usually based on the assumption that the sensor noises are Gaussian white, whereas it may be violated in practice. The statistics of sensor noise may be unknown yet norm bounded. Hence, a more general evaluation method to cover this case is needed. To achieve real-time performance evaluation of the inertial sensors subject to norm-bounded noises, a new evaluation function is proposed first. Then, we convert the evaluation issue into finding a minimum of the evaluation function, which can be viewed as an index to assess the sensor qualities. Next, for ease of online implementation, the evaluation function is reformulated and simplified by innovation projection. Moreover, an evaluation scheme is designed for the application of INS/GPS systems. Finally, two flight tests using the INS/GPS system for remote sensing are considered to validate the proposed method.