Simulation And Optimization On The Driving Structure Of The Liquid-Suspended Rotor Micro-Miniature Gyroscope

In recent years, micro-gyroscopes, which show good characteristics in their miniaturization, low-cost and low-power, has gained a fast development, and became an indispensable part in navigation and location system. The MEMS Center of HIT recently proposed a new liquid-suspended rotor micro-miniature gyroscope based on superhydrophobic effect and it applies a brand-new micro-gyroscope design structure whose rotor puts on the superhydrophobic coating by nanofabrication technology. In this way, rotor can reduce its friction force effectively as it is working, thus the rotational speed and stability is improved.Firstly, the content of this thesis is based on modeling and simulating the electromagnetic field and driving torque in liquid-suspended rotor micro-miniature gyroscope using simulation software Maxwell, establishing the3D micro-gyroscope model, and working out the stationary solutions by Maxwell equations and T-Ω arithmetic. The simulation results show the trends of driving torque under6different driving structure and they lead to the number combination of driving coils and phases. So the conclusion reaches to the12coils6phase24shots, or overlapped pulse signal of12coils as the optimized driving technology.Secondly, the paper moves on to optimize the coils on the stator, such as its ampere-turns and diameter. Simulations give the correlation between ampere-turns and driving torque and they go up linearly. The two parameters are required to meet the needs of greater driving torque, a specific space and heating as smaller as possible. According to these, the writer chooses ampere-turns of90, coil diameter of0.0267mm.Thirdly, the author studies the rotor size of radius and thickness due to their significant influences on driving torque. Surface fitting helps to get the equation describing the driving torque involving these two parameters. The paper takes the rotor radius of5.0mm and the thickness of2.5mm as the final decision among couples of feasible solutions.Finally, the experiments are operated under the micro-miniature gyroscope’s driving testing system to validate the simulation results. The experiments shows that12coils overlapped pulse signal can provide larger limited rotational speed and driving current than others. This phenomenon successfully verifies that12coils overlapped pulse signal is the best choice for driving the rotor. This paper aims at promoting driving system property and provides this gyroscope an optimized driving structure.