DOI: 10.3724/SP.J.1004.2013.02032

Acta Automatica Sinica (自动化学报) 2013/39:12 PP.2032-2042

Comparison of Two Methods to Implement Backward Swimming for a Carangiform Robotic Fish

This paper presents and compares two classes of backward swimming control methods for a biomimetic carangiform robotic fish. One is based on the traditional fish body wave equation, in which the body wave equation is inverted to generate a forward propagated travelling wave. The other is based on the bio-inspired central pattern generator (CPG) controller outputting rhythmic joint signals. The latter can further be divided into two subclasses: 1) phase-inverted CPG control, in which the phase relationship of forward swimming is inverted; 2) phase-amplitude-inverted CPG control, in which both phase relationship and amplitude are reversed. Analysis, simulation, and experiments are carried out on these three backward swimming control methods. Testing results show that the phase-inverted CPG control can result in a maximum backward speed, accompanied with a largest disturbance; the body wave based backward swimming control and phase-amplitude-inverted CPG control may lead to a similar maximum backward speed and smaller disturbance. In addition, when switching the oscillatory frequency in the body wave based backward swimming control, dithering will occur, and a special transition function to eliminate this phenomenon; while the dithering disappears in the CPG-based backward swimming controls. The above results will shed light on the enhancement of the maneuverability of the swimming robots.

Key words:Biomimetic robotic fish, backward swimming, central pattern generator (CPG), body wave, experimental comparison

ReleaseDate:2014-07-21 17:04:34

Funds:National Natural Science Foundation of China (61075102) and Natural Science Foundation of Beijing (4102063, 4122084)