Peter Lommel

Reactive inflight obstacle avoidance via radar feedback

Avoidance of unmapped obstacles is critical to autonomous flight in forested areas and urban canyons. The small vehicles capable of navigating in these spaces necessarily cannot carry the heavy and sophisticated sensor packages carried on large aircraft. We propose simple reactive feedback laws that enable obstacle avoidance for a hover-capable unmanned aerial vehicle (UAV) using a crude low resolution, small field of view radar sensor. The basic component in these laws is the reduction in the velocity component in the direction of the obstacle. We illustrate the performance of these feedback laws on a point mass double integrator model with velocity and acceleration limits. Simulation results in both 2-D and 3-D settings are presented.

Failure accommodating aircraft control

Describes development and performance analysis of a failure accommodation system for the commuter and business aircraft control recovery. First, system failures are detected and isolated using a hierarchy of techniques that is chosen to ensure minimal disruption of operations and to minimize the number of false alarms. Successive layers in the diagnostics hierarchy are increasingly invasive. Once a failure has been detected and identified, the failure can be accommodated in several ways, from passive pilot cueing to active autopilot reconfiguration. An autopilot reconfiguration algorithm to accommodate failures wherever possible is developed. Some preliminary pilot cueing strategies and displays to alert pilots to true failures, provide guidance on recommended responses, and inform the pilot of any reconfigurations are also introduced.

Active Failure Management for Aircraft Control Recovery

This paper describes development and performance analysis of an active failure management system for the commuter and business aircraft control recovery. System failures are detected and isolated using a hierarchy of techniques that is chosen to ensure minimal disruption of operations and to minimize the number of false alarms. Successive layers in the diagnostics hierarchy are increasingly invasive. Higher layers will be invoked only when lower layers indicate a potential problem. Once a failure has been detected and identi ed, the failure can be accommodated in several ways, from passive pilot cueing to active autopilot recon guration. This paper also describes some preliminary pilot cueing strategies and displays to alert pilots to true failures, provide guidance on recommended responses, and inform the pilot of any recon gurations. 1

Model-based failure management for aircraft control recovery

Abstract This paper describes the development and the performance analysis of an active failure management system for aircraft control upset prevention and recovery. The development of failure detection and system parameter identification algorithms that can reliably detect and isolate system failures with minimal disruption of normal operations constitutes the heart of the paper.