A Camera Based Method for the Measurement of Motion Parameters of IPMC Actuators

A visual measurement technique that is specifically developed to monitor the movements of ionic polymer metal composite (IPMC) materials in underwater conditions is presented. The proposed method is based on the extraction of appropriate information about the movement of an IPMC strip from subsequent picture frames. Since the time difference between these pictures is known, the system calculates both the displacement and the speed of the moving part. The processing algorithm implements a fully automated procedure for the localization of the point of interest (i.e., the edge of a microrobotic wing) and calculates the distance (displacement) between subsequent frames. This method is particularly useful for rather large and slow movements of the IPMC strips, as found in underwater microrobotic applications. The experimental results are compared with concurrent reference measurements by a high-accuracy laser-positioning system. A setup based on a low-cost camera offers a resolution of 0.5 mm or better, which is quite good for the specific application.