Hideto Suzuki

Fault Diagnosis of Space Vehicle Guidance and Control Systems Using Analytical Redundancy

Abstract For the efficient fault diagnosis of the space vehicle guidance and control system, the feasibility of the observer-based fault diagnosis using analytical redundancy is studied by a simulation analysis. The simulation using a reentry vehicle model shows that sensor faults and actuator faults can be detected and isolated promptly. The effectiveness of the robust observer, which is insensitive to the modeling error, is also shown.

The Effect of the Small Damping Sloshing to the Flexible Launch Vehicle Stability

Abstract The sloshing with a small damping can easily make the vehicle control system unstable. In this paper new index to evaluate the effect of sloshing to the attitude stability of the vehicle is introduced. This index includes the effect of bending interference as well as the sloshing mass location. Nyquist plot analysis shows that the sloshing with the same index has the same effect to the attitude stability and the interference between sloshing and bending affects the vehicle stability significantly.

System Design of the Pseudolite DGPS System for ALFLEX.

For a reusable space plane, the GPS navigation is essential to perform an accurate onboard navigation. Moreover, if the GPS navigation with the differential GPS technique performs high navigation accuracy and can be applied to the landing phase, the onboard GN&C system of a space plane is simplified and its weight is reduced. The National Space Development Ageacy of Japan (NASDA) and the National Aerospace Laboratory (NAL) have been studying the GPS navigation for an automatic landing. As one of the research items of the Automatic Landing Flight Experiment (ALFLEX), we designed and manufactured the pseudolite DGPS system for ALFLEX and evaluated its function and performance using real flight data. This paper presents mainly the system design results of the Pseudolite DGPS System for ALFLEX. And as the evaluation of these designs, the results of the ground experiment and the flight experiment by airplane are described.