Flight Control

Autonomous functioning via real-time monitoring and information management is an attractive ingredient in the design of any complex system. The inevitable presence of uncertainties due to malfunctions, environmental variations, ageing, and modeling errors, requires this management to be adaptive. Several projects are ongoing in the area of flight control and analysis, and are listed below.

Adaptive Control in the Presence of Rate Saturation

Actuator rate saturation nonlinearities are not often explicitly accounted for in the design of flight control systems. Rate saturated actuators pose the risk of failing, rendering a control system unstable and creating pilot induced oscillations (PIO). Two architectures are presented in this area to explicitly counter the effects of rate saturation within an output feedback MIMO adaptive control framework.

Sequential Loop Closure with Rate Limiter and Adaptation for Control of Hypersonic Vehicles

ghv The rate saturation architecture proposed in this section is formulated as an add-on to an existing sequential loop closure based guidance and control framework. The rate limiter functions by changing the guidance and control commands to push the system away from rate saturation. A buffer region is used to begin the limiting effects before a rate limit is reached. Tracking of the desired guidance command resumes as the aircraft leaves the designed rate saturation buffer region. Augmented output feedback adaptive laws are introduced to account for the effects of hard magnitude saturation additionally. This architecture is used to control a nonlinear hypersonic vehicle model in the presence of rate saturation.

Inner Loop Rate Limiter for Adaptive Control

This rate saturation architecture provides for guaranteed rate limiting within the bandwith of a control filter placed in between the controller and plant. The control filter synthesizes an input control rate which is passed through hard saturation blocks. Given the presence of the control filter, a relative degree two output feedback adaptive controller is used to control a plant of relative degree one. Augmented output feedback adaptive control laws are proposed and regions of attractions are mathematically guaranteed.

Shared Control Between Human Pilot and Adaptive Autopilot

Adaptive Kalman Filter