Improvement for the stability of an air-lubricated six-axis force/moment sensor

The air-lubricated six-axis force/moment sensor, a novel sensor developed using the gas lubrication principle, could avoid the coupling phenomenon and increase its precision to 0.2% full scale. During the sensor development, the stability of the nozzle-floating plate mechanism is a key issue, which is mainly caused by the “hammer phenomenon” that is affected by the size of the nozzle’s orifice. In this study, an air hammer stability criterion for the sensor was proposed and the design of the nozzle was optimized to avoid the air hammer phenomenon. The stable characteristics of the optimized nozzle were further verified with experiments through comparison with characteristics of the normal nozzle. In conclusion, the hammer instability phenomenon was averted through the optimal design of the nozzle and the precision of the air-lubricated six-axis sensor was improved, which can be applied in calibrating flexible tactile sensors with high-precision requirement.