Design and Experimental Study of a Novel Tilt Sensor Based on Magnetic Fluid

Magnetic fluid tilt sensors possess excellent shock resistance and strong adaptability to extreme environments, making them a highly promising new type of angle measurement device. This paper proposes a new miniaturized tilt sensor structure composed of a central permanent magnet, restoring magnets at both ends, magnetic fluid, and a Hall element. The inner diameter of the new sensor is only 8 mm and the overall length is 110 mm. The numerical electromagnetic field simulation model of the tilt sensor was established using COMSOL v6.1. Simulation analyses were conducted on the magnetic flux density distribution of the permanent magnet and the restoring force between permanent magnets. The structural dimensions of the central permanent magnet and restoring magnet were determined through analysis based on the simulation results. Subsequently, static and dynamic performance tests were conducted on the tilt sensor. The results demonstrate that the novel tilt sensor delivers excellent repeatability and low hysteresis error. The measurement range of the sensor is -35° to +35°, with a repeatability error of 0.46%, hysteresis error of 0.71%, linearity of 4.52%, and static sensitivity of 32.5 mV/°, as well as good dynamic response stability.