Measurement of force acting on a moving part of a pneumatic linear bearing

A method for evaluating the components of the force acting on a moving part of a pneumatic linear bearing is proposed. The total force acting on the moving part is accurately measured as the inertial force using an optical interferometer. Then, the components of the force, such as the force component depending on position, the force component depending on velocity, and the force component depending on tilt angle, are evaluated using the least-squares method. In the experiment, the total force acting on the moving part is measured with the standard uncertainty of approximately 0.001 N, which corresponds to approximately 0.003% (30 ppm) of the gravitational force acting on it (M=4.119 kg) of approximately 40 N (40 N). The experimentally evaluated values of these force components well coincide with the theoretically expected values.