A PILOTED SIMULATOR INVESTIGATION OF SIDE-STICK CONTROLLER/STABILITY AND CONTROL AUGMENTATION SYSTEM REQUIREMENTS FOR HELICOPTER VISUAL FLIGHT TASKS

A piloted simulator experiment was conducted to assess the effects of side-stick controller characteristics and level of stability and control augmentation on handling qualities for several low-altitude control tasks. Visual flight tasks were simulated using four-window computer-generated imagery depicting either a nap-of-the-earth course or a runway with obstacles positioned to provide a slaiom course. Both low speed and forward flight control Jaws were implemented, and a method for automatically switching control modes was developed. Variations in force-deflection characteristics and the number of axes controlled through an integrated side-stick were investigated. With high levels of stability and control augmentation, a four-axis controller with small-deflection in all four axes achieved satisfactory handling qualities for low-speed tasks. However, the four-axis configuration yielded degraded handling qualities compared to separated controllers for multi-axis control tasks and when reduced levels of stability and control augmentation were provided.