Computer Vision System: Measuring Displacement and Bending Angle of Ionic Polymer-Metal Composites

Abstract

A computer vision system for measuring the displacement and bending angle of ionic polymer–metal composites (IPMC) was proposed in this study. The logical progression of measuring IPMC displacement and bending angle was laid out. This study used Python (version 3.10) in conjunction with OpenCV (version 4.5.5.64) for the development of the vision system. The coding functions and the mathematical formulas used were elaborated on. IPMC contour detection was discussed in detail, along with appropriate camera and lighting setups. Measurements generated from the vision system were compared to approximated values via a manual calculation method. Good agreement was found between the results produced by the two methods. The mean absolute error (MAE) and root mean squared error (RMSE) for the displacement values are 0.068080668 and 0.088160652, respectively, and 0.081544205 and 0.103880163, respectively, for the bending angle values. The proposed vision system can accurately approximate the displacement and bending angle of IPMCs.

Design of Laboratory Stand for Displacement Measurement of IPMC Actuators

“…The bending angles of IPMCs were measured directly using the grid paper and calculating the arc length. After the results have been compared by using the laser displacement sensor ( Keyence LK- 160 G 152 laser transducer) to calculate the distance displacement and applying the Law of Cosine (also called the Cosine Rule) to obtain the bending angle [ 37 ].…”

Application‐Oriented Modeling of Soft Actuator Ionic Polymer–Metal Composites: A Review

“…Laser displacement sensors cannot accurately map the complex bending exhibited by IPMCs. [ 58 ] The laser displacement device is also affected by changes in beam refraction, making it unsuitable for use underwater or under humid conditions and on highly reflective objects. [ 58 ] Some studies use digital cameras to record the bending deformation of IPMCs to overcome the shortcomings of laser displacement sensors.…”

“…[58] The laser displacement device is also affected by changes in beam refraction, making it unsuitable for use underwater or under humid conditions and on highly reflective objects. [58] Some studies use digital cameras to record the bending deformation of IPMCs to overcome the shortcomings of laser displacement sensors. [53][54][55][56] The digital camera is usually placed on one side of the IPMC actuator (Figure 4b), and the tip displacement of IPMCs can be measured using a scale to obtain a grid paper.…”

“…Reproduced with permission. [58] Copyright 2022, MDPI. [56] Physical-Data driven machine learning based model…”

“…b) Digital camera setup to measure IPMC displacement. Reproduced with permission [58]. Copyright 2022, MDPI.…”