Development of sensing system of piezoelectric ceramics measuring contact pressure distributions. On techniques to increase measuring points and speed.

Improvement techniques of the sensing system proposed in the previous paper are described. By the sensing system, optional contact pressure distributions are measured automatically. In the system, piezoelectric ceramics are used and a special electric circuit is designed to measure electric charge in the material. In the electric circuit, the FET with the integral and peak hold circuits is used to increase the measuring points and speed. A sensing system of 20×10 measuring points and a 2-second measuring time is designed. By using this system, the contact pressure distributions for several problems are measured. The obtained total force and the pressure distributions are compared with the corresponding acting forces and the theoretical values.