Constructing a control system using a time–state control form for a fish-type balloon robot

A fish-type balloon robot (FBR) is a biomimetic robot that introduces twisting and pectoral fin motions into an airship robot. The FBR can move back and forth, right and left, and up and down using the twisting and pectoral fin motions. The FBR can propel itself without using a propeller; therefore, it does not injure people during accidental collisions. From this perspective, the FBR can be considered very safe. Therefore, the FBR can be used as a monitoring satellite and an advertising platform. In this paper, we construct an automatic control system for such practical FBR applications. The FBR cannot skid sideways; therefore, it can be considered a robot with nonholonomic constrains, based on the Brockett’s study. In this research, we apply control using a time–state control form. The outline of this control method is as follows. First, we converted the FBR motion model into a time–state control form using a time state and a state control unit. Second, we constructed a feedback control system that stabilized the state control unit. Third, we measured the propulsion characteristics of the FBR using the pectoral fin motion, which is necessary for controlling the FBR’s motion using the time–state control form and for analyzing the measurement results. In addition, we varied the pectoral fin motion to simulate how the FBR’s propulsion and turning angular velocities become similar. Finally, based on the measurement results, we constructed and executed a simulated control system.