<title>Strain-based shape estimation algorithms for a cantilever beam</title>

Abstract

Strain-displacement mappings based on linear and quadratic curvature assumptions are derived, compared for a numerical model and applied to a 4.37 m tapered composite boom with a circular cross-section. Displacement estimations are obtained for both the vertical and horizontal directions with displacement estimation errors of less than 0.2 mm in the vertical direction and 1 mm in the horizontal direction. Limitations on strain displacement algorithms for long booms are discussed as well as strain sensor noise effects on estimation accuracy.

An integrated GPS/gyro/smart structures architecture for attitude determination and baseline metrology

“…The assumption of linear curvature for the basis functions of each element has been used by both Baz, et al 14 and Gopinathan,et al 15 However, the estimation will degrade as the curvature departs from linearity. Accordingly, Vurpillot 16 , Andersson and Crawley 17 and Kirby, et al 18 have examined the use of quadratic local basis functions to describe the curvature over the length of each element The use of local linear basis functions is adopted in this paper.…”

“…If the gyro process noise value is equal for each gyro axis, then it is clear from Eqs. (17)(18)(19) that the three body axes uncouple and the Kalman filter can be divided into three simple two-state filters for computational ease. The block diagram in Figure 2 depicts the implementation of the integrated GPS/gyro/smart structures filter architecture.…”

Experimental Identification of the Structural Properties of an Ab 204 Helicopter Blade and Finite Element Model Validation

“…The strain measurements needed to identify the bending stiffness properties (when considering the approach called EI V2 ) could be also used to validate the numerical model as described by Kirby et al and Bogert et al 10,11 where a complete description of the methodology is reported. In the following, a brief description is reported for clarity purpose only.…”

Feasibility study on a strain based deflection monitoring system for wind turbine blades

“…Strain sensors are installed on a cantilever beam, and a deflection estimation method is presented in [19][20][21]. Refs.…”

“…In these cases, sensor positioning is important because it determines the strain sensitivity, which affects the accuracy of deflection estimation. To arrange the sensor positions, strain sensitivity is investigated by a FE model [19][20][21][22][23].…”