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The objectives of this research project are to design and build an instrumented shoe to measure the vertical ground reaction force (GRF) associated with a person walking or running. Sensor outputs are calibrated to actual GRF with an artificial neural network. Currently, GRF measurements require special equipment such as force plates or scientific treadmills. A force plate measures GRF over a limited area. A shoe insole fitted with sensors was identified as a good solution that allows free-range walking over arbitrary surfaces. Piezoelectric film sensors were chosen due to their low cost, flexibility and for being self-powered. Eight sensors were bonded to a conventional insole and wires attached. A data acquisition interface was prepared using a dSPACE MicroLabBox system, which contained digital filters for noise removal. Training and validation data were collected using a force-sensing treadmill available at the Parker-Hannifin Human Motion and Control Lab at CSU. A 3-layer feedforward network was successfully trained to approximate the training data. A separate data set was used to validate the trained network. A normalized root mean square error associated with training was 1.01, while the error in validation was 2.78.
Waskewicz College of Engineering
Khattab, Mohamad, "Ground Reaction Force Measurement with a Piezoelectric Insole" (2016). Undergraduate Research Posters 2016. 54.