External Load Stabilization Control Laws for an H-6 Helicopter Testbed

A helicopter with an externally slung load represents a dynamic two-body problem where the pilot is required to manage the load motion in addition to normal flight operating tasks. One method of reducing the pilot workload for external load tasks is to control the load motion by providing feedback of the motion to the helicopter control laws. Under the Adaptive Vehicle Management System (AVMS) Phase II program, external load stabilization using feedback to the flight control system, termed the Flight Control Load Stabilization (FCLS), has been developed. The FCLS design includes two architectures: one improves load damping, and the other improves handling qualities. Development of the FCLS architectures consists of model correlation, design using the classic root locus technique, control law tuning by CONDUIT® optimization and a parametric study, and piloted simulation evaluation. The design technique proved effective in identifying two architectures and the associated settings for load damping and handling qualities improvements. Piloted simulation results attributable to the FCLS system indicate improved Cooper-Harper Pilot Ratings and time to completion for three ADS-33E-PRF Mission Task Elements.