Tactile Cueing with Active Cyclic Stick for Helicopter Obstacle Avoidance: Development and Pilot Acceptance

Abstract

As helicopters land and takeoff in obstructed areas and on unprepared landing sites the risk of a collision with an obstacle is high. DLR have implemented a function to provide haptic feedback on the controls of a helicopter as a haptic pilot assistance for obstacle avoidance in order to evaluate its’ benefits for flying in obstructed areas. The cueing forces are provided in the direction away from the obstacle, and the intensity is a function of the distance to the obstacle. Two different force strategies were prepared for evaluation. The first was a steady, continuously increasing counter force in combination with an increasing spring gradient. The second was a repetitive, rectangular shaped pulsing force with increasing frequency and amplitude. As a proof of concept three EC135 pilots experienced in helicopter emergency medical service (HEMS) assessed the acceptability of such a system for operational use in the EC135 ACT/FHS simulator cockpit in DLR’s Air Vehicle Simulation Center (AVES). It achieved a high level of acceptance. This paper presents the development and evaluation results and gives recommendations for the further development.