Theoretical And Experimental Investigation Of Multi-Point Force/Moment Measurement Dynamometer

The accuracy in the measurement of force is essential in the robotic design,rocket thrust,manufacturing process and control,and biomedical and military equipment.To realize the multi-dimensional force/moment measurement,a multi-point measurement(MP-M)dynamometer model capable of measuring spatial force information is developed.The designed multi-point measurement system consists of a long dynamometer balance plate with eight tri-axial piezoelectric sensors uniformly distributed along two parallel lines to obtain the multi-dimensional force/moment measurement.The structural design is constructed to analyze the operating and measuring principle of the test system and,to represent the multi-allocated points of the dynamometer.The design theory of the dynamometer is established,including a numerical simulation model and an experimental calibration model.The numerical simulation model is carried on using the ANSYS analysis(FEM:finite element method)and the experimental calibration model is performed both the statically and dynamically calibration experiments using deweSoft software.The static calibration is performed using a manual hydraulic load application method and the dynamic calibration is performed using an impact load technique.The axial force 'Fx' and vertical force 'Fz' maximum up to 12 kN is applied in X and Z-directions respectively,and pitch moment 'MY' maximum up to 9.660 kNm is applied along the Y-axis on the designed multi-point(P1-P6).The FEM simulations measured results are approximately 98.5-100%and experimental calibration output results are minimum up to 92%and maximum up to 110%of the exerted axial force,vertical force,and pitch moments.The error difference between the theoretical and experimental analyses is under 1-10%.The experimental analysis results evaluate that the cross-talk error of multi-allocated points in the X-axis,Z-axis,and along Y-axis is less than 5%,linearity error is under 3.38%and repeatability error is under 2.44%.The natural frequency(?n)of the dynamometer in each coordinate is greater than 0.4 kHz.The measured results of theoretical simulation investigation and experimental measurement analysis are in agreement and both models proved the consistency of the studied model.