Design, Construction and Calibration of 6 DOF Force Torque Sensor for Measurement of Force and Moment of Tillage Implements

The presents study designed, constructed, and statically calibrated a 6DOF force torque sensor to measure forces and moments acting on a tillage implement. The instrument could measure the three orthogonal forces acting on the implement and the three moments acting around the orthogonal axes up to a maximum force of 5 kN and a maximum moment of 5 kNm. For mechanical design of the 6DOF force torque sensor, the finite element method and Solid Works software were used. The sensing element was constructed from AISI 1045 cold-drawn steel by machining. Strain distributions were analyzed to find the optimal strain node positions in the sensor to minimize cross-sensitivity between horizontal and vertical force measurement. The forces and moments acting on the sensor were measured using strain gauge bridges. A data logger (model DT800; DataTaker) was used for logging and saving data. Calibration of the measurement system was conducted by a calibration system designed for static calibration of a6DOF force torque sensor. The calibration results showed that the sensor had appropriateprecision, sensitivity, and good repeatability for measuring forces and moments. The results showed a high degree of linearity between bridge output voltage and applied force. The interaction of the applied forces and moments was not significant.