Precision Force Measurement Using the Levitation Mass Method (LMM)
This paper reviews the present status and future prospects of the levitation mass method (LMM), which is a precision mechanical measurement method. The LMM has been proposed and improved by the author for 10 years. The force generated by the actuator is measured as the inertial force of the mass levitated with sufficiently small friction using an aerostatic linear bearing and connected to the moving part of the actuator. During the measurement, the Doppler shift frequency of the laser beam reflected by the mass is measured with a high accuracy with the help of an optical interferometer. Subsequently, the velocity, position, acceleration, and inertial force of the mass are calculated using based on this frequency. Simultaneously, the current and voltage supplied to the actuator are measured.
Y. Fujii et al., "Precision Force Measurement Using the Levitation Mass Method (LMM) ", Applied Mechanics and Materials, Vol. 103, pp. 1-8, 2012