Modeling and Control of a Bionic Bladder System Designed for Bionic Underwater Robots

Bionic underwater robot is a new-type underwater robot which propelled and controlled by several bionic fins. Heaving motion is an indispensably function for most bionic underwater robots. Bionic bladder system is an apparatus which can realize both heaving and pitching control. It was inspired by biologic fish’s bladder. It was composed of a cylinder, a piston, a pipe, a rolling guide, two ball screws and two servomotors. The dynamic models of the bionic bladder system for heaving and pitching motion were established and based on which a dual-velocity control system was designed. Two control channels realized decoupling by setting different control cycles, and a PID controller are designed for each control channel. Simulations with the real design parameters and different control cycles were performed. Results indicated that the bionic bladder system can get a good control performance with proper control parameters.