Development of a circuit design for a capacitive pressure sensor, applied in walking robot foot

Abstract

The paper presents development of a circuit solution and a primary detector of a capacitive pressure sensor. Various structural variants of pressure sensors are considered, their characteristics are discussed. Operational principle and structure of the developed primary pressure detector are described, its schematic circuit diagram is presented. The dependency of output signal from the press force is empirically obtained, exhibiting a linear pattern. The estimated value of cyclic drift of the prototype device makes up 0.48% for the upper loading values and 1.08% for the lower ones, by respective weights of 10.69 and 29.03 N. The output signal of the experimental sample is close to linear in the load range from 0 to 8 N, and linear in the range from 8 to 50 N. The sensitivity of the prototype device to the applied pressure is 0.072 V/N. The developed sensor is applied in the feet of a walking robot to determine the zero moment point and calculation of pressure application point on foot.