Design of a Compact and Decoupled Jet Thruster System for Microgravity Flying Robots in Space Stations

A compact and decoupled jet thruster system for compact microgravity flying robots is presented herein to address the problems with poor passing ability of microgravity flying robots in a narrow area in space stations and large jet thruster systems. The jet thruster system comprises six duct fans and three sets of bidirectional deflector modules. It is stabilized by feedback control and time-sharing omnidirectional control, which facilitates rapid turns and agile motions. Additionally, two technical challenges are addressed: the development of a compact; lightweight; and decoupling multi-DOF jet thruster system that generates and rapidly switches orthogonal 6-DOF jets and the controller design of this jet thruster system that enhances stability and achieves high maneuverability. A fluid dynamics model is also developed to understand the influence of jet direction and amount on the controllability and stability of the robot. A good maneuverable, spheroid-shaped, and compact robot prototype is built, with a mass of 0.3 kg and a diameter of 92 mm, to validate these concepts. Experimental results from the integrated design method demonstrate that the robot achieves good maneuverability for translation and attitude adjustment motion. Moreover, the jet thruster system only occupies 18% of the robot's total volume.