Theoretical Modeling for a Six-DOF Vortex Inertial Sensor and Experimental Verification

This paper reports on a multi-axis fluidic inertial sensor that can detect three components of angular rate and linear acceleration. The sensor uses a vortex gas flow instead of the traditional linear gas flow as the inertial mass to detect the angular rate and linear acceleration. For this complex multi-axis sensing scheme, the theoretical modeling for the sensitivity and the cross-axis sensitivity of the sensor are discussed in detail. During the verification of the sensor's performance, the vortex was created by jetting the air supplied by an external air pump into a detection chamber via two opposing nozzle orifices in opposite directions. A configuration of microfabricated thermistors was constructed to realize multi-axis detection. The measured sensitivities of the gyroscope for the x-axis, y-axis, and z-axis were 0.429, 0.338, and 0.159 mV/°/s, respectively. The measured sensitivities of the accelerometer for the x-axis, y-axis, and z-axis were 0.185, 0.180, and 0.133 V/g, respectively. The results prove that the vortex sensor can effectively detect six-degree-of-freedom spatial motion.