Multi-objective optimization for efficient motion of underwater snake robots

E. Kelasidi, M. Jesmani, K. Y. Pettersen, J. T. Gravdahl
2016 Artificial Life and Robotics  
Underwater snake robots constitute a bio-inspired solution within underwater robotics. Increasing the motion efficiency in terms of the forward speed by improving the locomotion methods is a key issue for underwater robots. Furthermore, the energy efficiency is one of the main challenges for long-term autonomy of these systems. In this study, we will consider both these two aspects of efficiency, which in some cases can be conflicting. To this end, we formulate a multi-objective optimization
more » ... blem to minimize power consumption and maximize forward velocity. In particular, the optimal values of the gait parameters for different motion patterns are calculated in the presence of trade-offs between power consumption and velocity. As is the case with all multi-objective optimization problems, the solution is not a single point but rather a set of points. We present a weightedsum method to combine power consumption and forward velocity optimization problems. Particle Swarm Optimization (PSO) is applied to obtain optimal gait parameters for different weighting factors. Trade-off curves or Pareto fronts are illustrated in a power consumption-forward velocity plane for both lateral and eel-like motion pattern. They give information on objective trade-offs and can show how improving power consumption is related to deteriorating the for-ward velocity along the trade-off curve. Therefore, decision makers can specify the preferred Pareto optimal point along the trade-off curve. Moreover, we address some interesting questions regarding the optimal gait parameters, which is a significant issue for the control of underwater snake robots in the future.
doi:10.1007/s10015-016-0332-3 fatcat:f6txlcdlajg3fopnlpznu6k3gq