Dynamic Inversion Controller Design for Balloon-Launched Supersonic Aircraft

While balloon launch is one of the most cost-efficient ways to realize a supersonic flight experiment, it presents some issues for the controller. D-SEND#2 is one flight experiment of this kind which was carried out in 2015. An unpowered test vehicle was lifted to an altitude of 30 km by a balloon and then released. After separation, the vehicle's onboard flight control computer selected a target Boom Measurement System (BMS) according to the separation point. The vehicle then autonomously flew to the BMS selected and established the prescribed sonic boom measurement flight conditions. The design of the guidance, navigation, and control system for the D-SEND#2 flight test was exceptionally challenging, and it was solved by a combination of a sophisticated guidance law and a control law based on dynamic inversion and time scale separation. This paper describes a controller design method for a balloon-launch flight experiment and applied it to a D-SEND#2 control system design. Flight results are presented to show the effectiveness of the controller design method.