A non-contact capacitive sensing system for robotic lower-limb prosthesis, comprising a sensing front end, a signal sampling unit and a signal processing unit. The sensing front end is composed of capacitance electrodes inside the prosthetic socket, and the capacitance electrodes locate between the prosthetic socket and the stump sock. Each capacitance electrode forms a capacitor with the human body. The signal sampling unit is composed of the CTD module and the control module. The CTD module measures capacitance values by calculating the ratio of discharge-and-recharge cycles between the under-test capacitors and the reference capacitor. The signal processing unit comprises the filter module and the communication module. The capacitive sensing system is highly repeatable in signals, resistant to sweat, and reliably dressed on a human body. The system performs well regardless of residual limb length and residual muscle strength. It can be widely used in the field of robotic lower-limb prosthesis.
