Research On Non-contact Measuring Technology Of Stiffness For Elastic Element With Large Stiffness

This thesis explores an elastic element consisting of a spring tube andfeedback rod. Elastic elements with large stiffness are consisting of a class ofelastic elements that existing stiffness measuring technologies can’t measureaccurately. Elastic elements play an important role in the force feedback of servovalves. With the increasing requirements of the output power and controlaccuracy of servo systems, the requirements of the stiffness characteristics ofelastic elements with especially large stiffness also become higher. To ensure thestiffness characteristics of elastic element mainly depends on the stiffnessmeasuring technology. The stiffness measuring technology of the elastic elementplays a crucial role in improving the performance of a servo system. This papermainly studies the stiffness measuring technology for large stiffness elasticelements.First, for analyzing the limitations of the large stiffness elastic elementmeasuring devices, this thesis article analyzes the errors of measurementprinciple, structural distortion and data collection. Stiffness measurementaccuracy is affected by deformation and contact deformation between the hole inthe force measuring bar and the head of the spring tube. This error analysis isnecessary for developing a new measuring scheme.Second, targeting a different improvement challenge, the design anddebugging of the actual system will depend on the different types of errorsencountered. The new measuring system cancels the position adjustment plate ofstructure to improve the structure stiffness of the measuring platform, changesthe displacement sensors of displacement measuring principle and thedisplacement measuring object, uses the Dixon culling criteria to carry out thegross error and calculates the stiffness with a linear fit data processing method,Both algorithms effectively reduce the effect of random measuring error.Finally, verifying the influence of various factors on the stiffnessmeasurement precision, test experiments are made on the new measuring system,testing both this single factor as well as the general experiments. Theexperimental results show that the error analysis is valid and that the performance of the new measurement system for elastic element stiffness withlarge stiffness is stable, reliable and of high precision. The technology can meetthese measurement requirements.