Nonlinear modeling of low cost force sensors

In this paper, nonlinear modeling of low cost force sensors is considered for force control applications in robotic or biomechanical applications. Commercial force sensors are often expensive, with a limited use in severe conditions such as the presence of a strong magnetic field. On the contrary, thin film piezoresistive sensors such as the Tekscan Flexiforce and the Interlink FSR sensors are of low cost and can be considered in such an environment. Only a few information is however available on their dynamic properties. We therefore provide an experimental study of their dynamic behavior, showing nonlinear properties. Identification is then achieved, and a compensation model is proposed. A force control experiment is finally presented to evaluate the compensation scheme.