Pedaling torque reconstruction for half pedaling sensor

Electrically Power Assisted Cycles (EPACs) have been gaining increasing attention worldwide during the past few years. Market analysis show that cyclists prefer torque assisted EPACs over velocity-based ones. A torque assisted cycle requires an estimate or measurement of the cyclist torque, which increases the cost and complexity of the set-up. Among the viable solutions, sensors mounted on the pedal axis have several advantages in terms of packaging and cost; unfortunately, they are capable of measuring the torque exerted only on one pedal. This paper deals with the development, implementation and validation of two algorithms to estimate the entire revolution torque using a half pedaling sensor. The algorithms are based on the iso-power or iso-torque assumptions (checked on a high-end training bicycle). The algorithms are validated using road measurements, showing that a sufficient level of accuracy for EPAC is reached.