Digitalization and development of a torque sensor based control system and implementation of the algorithm using a micro-controller

Abstract

Mechanical vehicles are a part of our daily lives. Some of them are driven by electrical power whilst others are driven manually by effort of the driver through pedaling the vehicle. Given that the majority of the population of the world is still under poverty, the dependency of people have on manually driven vehicles is more, as they are both cheaper to own and maintain. However, continuous utilization of man-driven vehicles like, rickshaws, vans and wheelchairs, can have strenuous effect on the rider. Our aim for the project is to reduce this human effort by assisting the rider with an electrical input when the load on the vehicle becomes high. Thus, we developed an intelligent control system, with the help of a micro controller, which would work in conjunction with a Torque sensor to run a motor during some per-defined conditions. This makes the operation of manually-driven vehicles easier by assisting the rider, when necessary, with power from a motor. This enables us to change the manually driven vehicle into a hybrid vehicle. The inclusion of the micro-controller is to make the final circuitry simpler and easier to operate. In this circuit design the user can simply replace the chip, instead of changing the entire circuitry as in the former analog circuit, when any wear and tear takes place. The on circuit micro-controller has a pre installed algorithm which controls the overall decision making of the system. It automatically switches the motor both on and off based on the pre-installed threshold and cutoff voltage values. Our objective is to reduce the riders from the excessive physical exhaustion that mainly occurs when a high load is present on the vehicle or while initiating the momentum from either rest or low speed to generate a moderate speed. A motor helping the pullers/users only during these phases eradicates exhaustion to a significant level, and at the same time saves energy by limiting the over-use of the motor. Therefore, the digital circuit enables us to significantly reduce the human effort needed whilst keeping the identity and driving mechanism of the existing manually driven vehicles. Our developed algorithm and the designed digital circuitry with the micro-controller are usable with all the existing manually driven vehicles that involve pedaling. In our project, we have implemented it in an electrically assisted wheelchair for physically disabled people.