Hiroyuki Ichikawa

Robust Pole Assignment for Vibration Control of Flexible Structures

This paper proposes a method of structure/controller design by robust pole assignment for active vibration suppression of flexible structures. The proposed method assigns the closed-loop poles at the specified point in the complex plane and quasi-minimizes the condition number of the closed-loop modal matrix via structure/controller design. Reducing the condition number improves stability robustness and control performance of the designed closed-loop system. This paper also introduces a new index of condition number for the cost function. Use of this index in place of an actual condition number reduces computational effort and improves problem solvability significantly. Feasibility of the proposed method is demonstrated with numerical examples.

New DXHS algorithm for periodic vibration control — Numerical simulation and experimental result

The new type of active noise feedforward control (new DXHS algorithm) was proposed and its local stability was analysed to show that the new algorithm can overcome drawbacks of filtered-x least mean square (FxLMS) algorithm as well as delayed-x harmonics synthesiser (DXHS) algorithm. This paper verifies with simulations and experiments how well the new DXHS algorithm works. For the simulations and the experiments, the new DXHS algorithm is transfered from the continuous-time version to the discrete-time version. By observing global behaviors, it is made clear some issues on transient responses until the adjustable parameters converge to the stable equilibrium points.