<title>Controller implementation on infinite-order structural systems using distributed sensors</title>

Abstract

The design of spatially shaped distributed sensors for the control of infinite order structural systems has become a topic of interest in recent years. Sensor shape optimization techniques were developed for the design of optimal controllers on infinite order structural systems. In this paper, we investigate methods for the implementation of distributed sensors using polyvinylidene fiouide (PVDF) film. The complexity of the sensor shapes depends on the mode shapes of the flexible structure and the performance measure of the controllers. The sensitivity of the sensor shape on the performance of the controller is being investigated. The problems associated with the practical implementation of distributed sensors with PVDF film are also identified.The shapes of the distributed sensors for the implementation of a linear quadratic regulator (LQR) and a pole-placement controller have been determined. These sensors are implemented on simple cantilever beam test articles using PVDF film. The details of hardware implementation of the controllers are presented. The closed loop performance of the controll'ers are compared with simulation studies. The sensitivity of the shapes of the distributed sensors for the LQR and pole-placement controllers is discussed.

Parallelism error analysis and compensation for micro-force measurement

“…After assembly, the force measurement system was controlled. There have been more studies on the control for null balance than on the mechanism analysis and the design [9][10][11][12][13][14][15]. To control the displacement, the digital PID method was applied to the system.…”

“…Thus, even though mechanism analysis and design are needed to improve system performance by heightening the resolution, broadening the measurement range, and eliminating the corner loading error, papers on mechanism design related to the null balance type force measurement system, especially on the parallelism error analysis, have not been found in the literature. Several papers on control and filter design have been reported [9][10][11][12][13][14][15].…”

The modelling and design of a mechanism for micro-force measurement

“…In addition to the use of load cells and null balances, there are several other methods for force measurement, that use phenomena such as the change in frequency of a vibrating cord system, change of magnetic properties under loading, gyroscopic force in the gyroscopic force measuring apparatus and piezoelectric strain in piezoelectric strain sensors such as those using a PVdF cantilevered beam and piezoelectric thick films [2][3][4][5][6].…”

“…However, a few papers on control and filter design for the null balance type microweighing systems were found in the literature. Several structures and ideas regarding their modification were proposed in patents [5][6][7][8]. The paucity of reports on mechanical design procedure encouraged us to propose the present design.…”