Modernized Control Laws for UH-60 BLACK HAWK Optimization and Flight-Test Results

Abstract

Modernized control laws were developed to provide an attitude-command/attitude-hold response type for the UH-60 BLACK HAWK helicopter and thereby afford improved handling qualities for near-Earth operation in night and poor weather. The inner-loop system modernized control laws were implemented using the 10% authority stability augmentation system actuators and was evaluated in an EH-60L helicopter. Central to addressing the significant resource and technical challenges of this project was the extensive use of a modern integrated tool set. System identification methods provided an accurate flight-identified aircraft response model and allowed the efficient isolation of discrepancies in the block diagram-based simulation model. Additional key tools were real-time rapid prototyping and a well-designed picture-to-code process. Control laws were tuned to achieve the maximum design margin relative to handling qualities and control system performance requirements. The optimized design was seen to be robust to uncertainties in the identified physical parameters. A flight-test evaluation by three test pilots showed significant benefits of the optimized design compared to the BLACK HAWK standard flight control configuration.