Multifunction Stair Climbing Device And Control System Design

Wheelchairs play an important role in the life of the elderly and disabled ones. With the arising problems of the aging population and the increasing disabilities, they will surely act as an irreplaceable factor in improving the life of the special group. Traditional manual wheelchairs and even powered wheelchairs do not have the capability to climb up stairs or cross the barricade, which restricts the freedom of the user's requirements. On account of the issue above, this thesis focuses on the multifunctional mechanisms for climbing stairs, which is dedicated to be available for both use on the ground and stairs.A novel climbing structure with wheels is presented in this paper. The front wheels which act as master wheels on the ground are driven by motors integrated in the wheel rim. The rear wheels are designed for climbing stairs, each of which is composed of a hub disc and a rim. The climbing function of the mechanism is achieved by the eccentric drive shaft connected with the hub disc and the control system is based on the BLDC motors.According to the motor theory and the double close loops of speed and current control, the hardware and software of the motor driver are designed. The hardware is configured with Digital Signal Processor (DSP) as controller and Intelligent Power Module (IPM) as power driver. Moreover, over-voltage and under-voltage protection circuit and over-current protection circuit are designed. The software of the system is developed with modularization method and realizes the digital control of the whole system.Finally, part of the model is built for the function of climbing stairs and the debugging of the whole system is finished. The results prove the quality and the feasibility of the mechanism. Compared with the structure of wheel clusters, the track of the movement is optimized. The performance of speed control corresponds to the demand of the mechanism well.