Calibration and optimization of FSR based smart walking assistance device

Abstract

The movement of the legs is a very important activity and routine exercise in human life for the fundamental necessity of mobility. Few smart walking assistance (SWA) devices have recently been developed to support walking for older people and osteoarthritis patients. A smart walking assistance device was developed using force-sensitive resistors (FSRs) to support mobility. Precise motion control of the walker wheel is necessary to direct the SWA device in the intended direction. Due to the inaccuracy in motor manufacturing and its internal resistances, the motors and respective attached wheels run at different speeds even though the electrical input signal is the same. The asynchronization in the motors attached to the wheels leads to deviation in the intended path of the user. It is very important to follow the exact path by SWA as per the requirement and safety of the user. In this paper, the speed asynchronization issue of the SWA device is addressed. The asynchronization problem is solved using mathematical modeling followed by implementing effective speed control techniques to provide speed synchronization in all the driving motors of SWA. Further, the power consumption of SWA is also analyzed. It has been found that the proposed SWA device, after calibration and optimization with pulse width modulation (PWM) mapping performed a successful operation with a power-saving of 27.62% at no-load and 77.33 % at load conditions.