Structured MIMO H-Infinity Design for Dual-Stage Inertial Stabilization: Case Study for HIFOO

The paper reports on a control design for an experimental platform that contains two aligned motorized gimbals stabilizing an optical payload around a single axis using measurements from an inertial angular rate sensor (MEMS gyro). Such a laboratory system represents a simplified testbed for the more practically useful line-of-sight stabilization. The paper defends the choice of the control configuration and argues that when using MIMO design procedures, enforcing some structure upon the transfer function matrix makes the controller implementation and fine-tuning easier. Such structural constraints were taken into consideration in the computational Hinf design by using the publicly available HIFOO solver based on algorithms for non-convex and non-smooth optimization. Results are contrasted with the controllers designed with classical methods and full MIMO Hinf optimization.