Coordinated Control of Altitude and Pressure Difference for Stratospheric Super-Pressure Balloons

Near space has significant advantages in data communication and has become a strategically contested field for development among various countries. As a type of persistent information platform in near space, super-pressure balloons have received increasing attention in recent years. However, the coordinated control of altitude and pressure difference for super-pressure balloons remains a technical challenge faced by researchers. This paper installs phase-change gasbags using ammonia as the phase-change working fluid on the structure of traditional super-pressure balloons, designing a backstepping controller to control the volume of the external phase-change gasbag to achieve altitude control of the super-pressure balloon. Additionally, the mass flow rate of ammonia in the internal phase-change gasbag is planned over time. Compared to traditional super-pressure balloons, simulation experiments show that super-pressure balloons with both internal and external phase-change gasbags have significant advantages in altitude and pressure difference coordinated control.