Design and implementation of a rapid automated defects inspection system for resistive touch panels with a PID-like fuzzy controller

The main purpose of this research is to improve the inspection speed and increase the inspection accuracy of the homemade three-dimensional automatic inspection system for resistive touch panels (TDAISRTP) bu using a PID-like fuzzy controller. First, the transfer functions are established to characterize the motion dynamics of the three-dimensional gantry stage. Then, the PID controllers and the PID-like fuzzy controllers are developed to improve the tracking responses. This allows the inspection probe to position any desired inspection point and track any desired inspection locus of touch panels (TP) rapidly and accurately. Besides, the processing circuits are designed to detect a touch-point coordinate of a touch event. In addition, the software control interface of the TDAISRTP is developed in the envioronment of C++ Builder language. This facilitates the TDAISRTP to compare the desired inspection path and the detected path and automatically validate the linearity test, accuracy test, single touch point test, touch pressure test, and reliability test. For performance comparisons, simualtion and experimental studies are carried out. It is seen the proposed TDAISRTP with a PID-like Fuzzy controller shows a better tracking response than a inspection systems with a PID controller. In addition, the inspection speed and the positioning ability are significantly improved as compared with commercial touch panel inspection systems.