This paper shows a new design and prototyping method for a bending pneumatic rubber actuator and its application to a soft-bodied manta swimming robot. The design is based on optimal design using non-linear finite element method, in which geometrical and material non-linearity are considered and fabrication process is based on a rapid and efficient prototyping system using a CAD/CAM based rubber molding process. In this paper, the characteristics of several possible actuators are analyzed and evaluated to lead to an optimal actuator design. The actuator works very well with smooth and soft motion. The manta swimming robot in which the developed actuators are embedded is also designed based on non-linear finite element method. The developed manta swimming robot is made only of rubber and it swims in water smoothly as if it was a living fish. The experimental results of the manta robot motion show that good agreement with those of analytical results.

Deals with (1) a manoeuvre test in the horizontal plane of a fish robot equipped with a pair of apparatus for pectoral fin motion on both sides and (2) guidance and control of the fish robot in the horizontal plane. The fish robot consisting of a fish body model and a pair of apparatus for pectoral fin motion has high performance of manoeuvrability such as turning in the same position. The use of fuzzy control enables the fish robot to perform rendezvous and docking with an underwater post in a water current.

Deals with the configuration of autonomous underwater vehicle (AUV) for inspection of underwater cables considering low hydrodynamic drag, sensor alignment, collision avoidance manoeuvre, turning manoeuvre and rolling motion. The AUV consists of a fuselage of body of revolution with low hydrodynamic drag, fore and aft horizontal wings, upper and lower vertical tails and a pair of horizontal thrusters at both sides of the aft horizontal wings. The shape of the forward horizontal wing and that of the rear horizontal wing can be determined by use of a nonlinear optimization method under the constraints of magnetic sensor alignment for cable tracking, dynamic stability in the vertical plane and the performance of the collision avoidance manoeuvre. The performance of the turning manoeuvre and rolling motion are attributed to thrust force difference between a pair of thrusters at both sides of the rear horizontal wing, because the shapes of the upper and lower vertical tails can be designed from the viewpoint of the dynamic stability in horizontal plane.

Reports analysis and simulation studies for the co-ordinated control of multiple manipulators on a free swimming underwater robot. The control objective is to perform an open loop control of the end effector position of one of the arms. A formulation is derived for both the inverse dynamics and inverse kinematics of an underwater robot with multiple manipulators, having a redundancy in degrees of freedom (DOF) of motion, in the presence of external generalised forces. The method is applied to a model of an underwater robot comprising a 6 DOF mission arm and a further pair of 2 DOF paddling arms used for stabilisation in a free swimming condition. The numerical simulation results show the effectiveness of the presented co-ordinated control method with the assistance of the stabilising arms.