Development of Torque Sensor Based Electrically Assisted Hybrid Rickshaw

Abstract

Cycle rickshaws are the most popular form of transportation inside the cities of Bangladesh, especially for its route and time-flexibility and door-to-door services. Considering the fact that a significant portion of underprivileged population of Bangladesh is directly or indirectly dependent upon the rickshaw-pulling profession, the necessity of scientifically thinking about its improvement and modernization was apparent. This paper describes a research and development project of Control and Applications Research Group, BRAC University, aiming to modernize these green fuelfree transports of Bangladesh using power-assistive technology. This involves design and implementation of an intelligent control system that would make the rickshaw pulling task easier-to-feel by assisting the human power with a motor, turning it into a hybrid vehicle. The motivation of the project was to relieve the rickshaw pullers from the excessive physical exhaustion associated with the task, which mainly occurs while initiating the momentum from rest or low speed to a moderate speed. A motor helping the pullers only during this particular time eradicates this exhaustion to a significant extent, at the same time saves energy by limiting over-use of the motor. A torque-sensor was involved to determine the need-of-assistance a puller feels at a particular time, and an external controller in addition to the motor controller was designed and tested. The model was developed so as to save energy, limit overuse, and keeping the identity and driving mechanism of old rickshaws. An idea of battery charging infrastructure using Solar- Battery-Charging-Station is also mentioned as a core factor of the project.