Development and Evaluation of a Proportional Displacement Sidearm Controller for Helicopters

Abstract

Associated with the development of fly-by-wire control systems for use in helicopters has been the prospect of replacing all of the current manual flight controls in the cockpit with a single sidearm controller. For the most part, the technology available for this concept has consisted of variations of force sensing sidearm controllers. The human proprioceptive system, however, does not perform optimally in force discrimination and stable maintenance of force outputs. One consequence of this is that operator feedback with respect to direction and magnitude of control input with force sensing manual control systems is relatively poor. An alternative approach applying proportional displacement sensing rather than force sensing was developed and evaluated via laboratory studies and flight tests in a research helicopter. The results to date indicate that pilot workload and performance with a displacement sensing controller are equivalent to conventional controls and superior to a force sensing controller across a wide spectrum of flight conditions and maneuvers. All four control functions (i.e., roll, pitch, yaw, and collective) were in one hand in both the force and displacement sensing configurations. A sidearm controller utilizing displacement sensing rather than force sensing retains most of the advantages of the latter (e.g., simplicity, compactness) while offering superior compatibility with human operator sensorimotor characteristics.