Smart Wheelchair Stair Lift Using RFID Detection Method and Fuzzy-PI with PLC Ladder Control

Abstract

This paper presents the development of wheelchair stair lift with an intelligent control system that aim to apply for helping the mobility of ageing, disabled and wheelchair people who are suffered from any inconvenience causes of building stair usages and also served for the fire stair evacuation path in the same time. The stair lift is controlled by PLC with the fuzzy proportional plus integral (F-PI) controller combined on their driver functions called as fuzzy ladder control which can generate an appropriate setting voltage and torque to maintain a target position and speed of stair lift when it move along the stair path with shorter time of accessing, travelling and dwelling process. To gain the precise value of target position and speed , the DC motor drive with smart steering gear box that are coupled on two stair guide rails is designed for acting easily as a linear moving control by F-PI controller. By several tests of the unknown characteristics of wheelchair users, the F-PI controller can solve this kind of problems with more efficiency because of the main advantage of fuzzy logic is that no mathematical model is required but can be achieved higher performance with the effective tuning parameters especially in an initial setting process. For more efficiency, the RFID detection method is applied to use for identifying and automatically accessing of wheelchair users who want to use this stair lift with some important data such as their name, age or weight as the prior knowledge data of the initial setting process. By applying the proposed system, performance has been improved by mathematical analysis, solid work simulation, matlab simulation and several tests at laboratory room and real building stair. The results are better than the conventional PI control with more accuracy, correctly, smoothly, stability and safety. Finally, the all system can work well as design concept and the future work will further improve the system performance both in mechanical and control part for more practical to use in any real stair usage.