This paper presents a control design for flexible manipulators using piezoelectric actuators bonded on nonprismatic links. The dynamic model of the manipulator is obtained in a closed form through the Lagrange equations. Each link is discretized using finite element modal formulation based on Euler-Bernoulli beam theory. The control uses the motor torques and piezoelectric actuators for controlling vibrations. An optimization problem with genetic algorithm (GA) is formulated for the location and size of the piezoelectric actuator and sensor on the links. The natural frequencies and mode shapes are computed by the finite element method, and the irregular beam geometry is approximated by piecewise prismatic elements. The State-Dependent Riccati Equation (SDRE) technique is used to derive a suboptimal controller for a robot control problem. A state-dependent equation is solved at each new point obtained for the variables from the problem, along the trajectory to obtain a nonlinear feedback controller. Numerical tests verify the efficiency of the proposed optimization and control design.

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This work presents an optimal design methodology for piezoelectric material positioning in structures aiming at vibration measurements. The main objective is to find the optimal location of piezoelectric sensors using a suitable topology optimization strategy. The sensors location is determined by an optimization formulation that defines where the material should have piezoelectric properties. The objective of the optimization is maximizing observability, measured by means of the trace of the Gramian matrix. The control strategy development is based on a truncated modal system model. A case study and its results are presented and discussed, showing that the optimal placement of the piezoelectric sensors in a cantilever beam can be suitably achieved through the proposed approach.

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