Application of force sensors in microprocessor-controlled actuators

With the new generation of actuators, produced by the company AUMA, the torque needs of the armature can be continuously supervised. The essential item in the measurement of the torque is a sensor made of a special steel with resistors applied in thick-film technique. The optimal design of the force sensor was reached through FEM simulation. The K-factors for longitudinal or transversal forces of resistance were determined in an experiment with the deflection of a laterally loaded cantilever. The measurement of the output signal directly at the sensor shows a good linearity of the characteristic curve. After 30,000 load cycles, no drift of the maximum output signal can be detected. The offset drift (signal when F=0) lies at 3 percent, which is within the given requirements.