An Embedded Friction Sensor Based on a Strain-Gauged Diaphragm

Abstract

A new design of friction sensor, intended for use in industrial process applications, such as metal forming, has been developed. The sensor consists of a diaphragm whose outer surface is flush with the surface of the tool and whose inner surface is instrumented with strain gauges. Relative to previous sensor designs, this sensor offers reduced disturbance of the frictional interaction between the tool and the workpiece. A proof-of-concept prototype has been constructed and tested in a laboratory test apparatus. The results of testing validate the anticipated performance, based on finite element modeling. The sensor is able to measure both shear and normal forces and, of greater significance, is able to simultaneously differentiate between the two types of loading.