Chuan Zhi Mei

Study on Fluidic Gyroscope Zero Temperature Compensation Method

This paper had studied on the zero temperature compensation of fluidic gyroscope based on MEMS thermistor. Through the analysis of temperature characteristics of jet gyro sensitive element, two methods of comparison of zero temperature compensation was compared. Then, introduction of SCM and temperature sensor, to achieve zero temperature compensation for gyro output signal. The experiment shows: after compensation, zero voltage variation gyro reduced from 150mV to 10mV, working temperature range from room temperature to-40°C ~+55 °C. The fluidic gyroscope zero temperature compensated with zero drift is low, wide working temperature range advantages.

Study on a Craft Simulation Technology for the MEMS Thermal Element

On the basis of the craft manufacturing and designing about micro fluidic gyroscope, according to analyze the craft information and studying on the process simulation technology about the MEMS thermal components. Established a basic model of t the craft structure about the MEMS thermal components, based on this model, the L-Edit editor to edit creating a complete mask layout structure; studying a simulation method of craft process, the use of the technological editor which development based on the TCL/TK language to draw out the craft process document, then reconstructed the layout structure based the craft process in a 3D platform. It could be used to detect the rationality of the process program technology.

Study on Fluidic Gyroscope Linearity Compensation Method

Based on the linearity of the MEMS thermal element fluidic gyroscope compensation. By analyzing the results of the linear characteristic of the fluidic gyroscope sensor output, comparator linearity compensation two implementation methods, the introduction of the microcontroller and the temperature sensor, to achieve the linearity compensation of the gyro output signal. The experiments show that: after compensation, the non-linearity of the fluidic gyroscope5%down to 0.5%, to-120°/s~+120°/s measurement range from-40°/s~+40°/s Fluidic gyroscope linearity compensation with low non-linearity, wide measuring range.

Finite Element Analysis of the Drum-Shape Cavity Fluidic Gyroscope Sensitive Mechanism

Against the deflect that the existing fluidic gyroscope airflow channel structure was easy to cause the flocculating flow. This paper presented a kind of elliotic-drum flow cavity structure. Using the finite element method, calculated the flow field in the closed cavity at different angular velocity input. The results showed that the gas flow path of the main airflow distribution was streamlined, there did not form the vortex area which could reduce the energy additional losses, when the angular rate input changed, then the jet flow field distribution didnt keep equal and symmetrical, the jet speed difference at the hot sensitive wire changed with angular velocity, thus revealing the drum-shape cavity fluidic gyroscope sensitive mechanism.

Influence of Thermal Wires Position on Fluidic Gyroscope with Different Cavities

The influence of thermal wires position on resolution of fluidic gyroscope with three different cavities was researched. Using Finite element method we calculated two-dimensional flow distribution of fluidic gyroscope with rectangular cavity and two streamlined cavities when the thermal wires are in different positions. As the results shown: define d is the distance between thermal wires and the nozzle along the fluidic beam propagation direction, when d ≥ 13mm, velocity 4SSUM in streamlined cavity 1 is bigger than velocity 2SSUM in streamlined cavity 2. When d >16mm, velocity SX of two streamlined cavities decrease faster than RX of rectangular cavity, which reduce the vortex phenomena in cavity. With the distance away from the center axis of cavity increases, the velocity gradient increases, and increasing the distance between two thermal wires within a certain range can increase velocity difference of two when angular velocity ωi inputs, temperature difference increases, so it increases the resolution of fluidic gyroscopes. This paper has an instructional role on structure optimization and performance improvement of fluidic gyroscopes.

Research of the Impact on Distance between Thermal Wires and Nozzle for Fluidic Gyroscope

The impact that distance between thermal wires and nozzle on flow distribution of fluidic gyroscope with three different cavity structures was researched. Using the Finite element method we calculated the two-dimensional flow distribution of fluidic gyroscope with rectangular cavity and two streamlined cavity structures when the distance d between thermal wires and nozzle is different. The results show that: flow velocity at the outlet in two streamlined cavities is larger than that in rectangular cavity, which is 28.87% and 28.91% of flow velocity at the nozzle respectively; the velocity in the three cavities decrease with d, the velocity in streamlined cavity 1 is always larger than that in streamlined cavity 2. When d = 16mm and 17mm, there are a larger velocity and a smaller x-axial velocity of the fluidic beam center in streamlined cavity 1, and velocity difference of two thermal wires increase, so the resolution of fluidic gyroscope can have an improvement.

Influence of Sensitive Cavity Structure on the Resolution of Fluidic Gyroscope

The flow distribution of fluidic gyroscope with three different cavities was researched when angular velocity ωi is input. Using Finite element method we calculated two-dimensional flow distribution of fluidic gyroscope with rectangular cavity and two streamlined cavity structures when ωi input. The results show that: with ωi increasing, the fluidic beam centers in three cavities have a more deviation on one side, while in two streamlined cavities it deviates obviously. When ωi is 10rad/s, velocity difference of two thermal wires in streamlined cavity 1 and cavity 2 increase 42.59% and 59.30% respectively compared with rectangular cavity, velocity and y-axial velocity of two thermal wires in streamlined cavity 1 are smaller than rectangular cavity but larger than streamlined cavity 2, but x-axial velocity of two thermal wires in streamlined cavity 1 are smaller than other two cavities, and so is ωi = 15rad/s. It also shows that velocity difference between two thermal wires in streamlined cavity 1 is larger than others, and temperature difference is larger, which can improve the resolution of fluidic gyroscope. This article has laid a theoretical foundation to further enhance performance of fluidic gyroscopes.

Study on Nozzle Array Structure Fluidic Gyroscope

This paper reports about a nozzle array structure fluidic gyroscope. The gyro used setting sub-nozzle around the main nozzle to inhibit the attenuation which had been caused by the main nozzle jet column spread out and to increase the angular velocity difference of sensitive element in the thermal resistance wire when the jet flow rate had been input, thereby to improve the performance of the jet gyro. The test results showed that: a resolution of better than 0.1°/s nozzle formation jet gyro sensitivity better than 10mv/(0.1°/s), the measurement range is better than ± 60°/s; non-linearity of better than 1%.The impact of the gyroscope impact resistance capability, small size and wide range of applications.

Study on Improving Resolution of Fluidic Gyroscope

This paper presents a comparative study to improve the resolution of the fluidic gyro. Using ANSYS-FLOTRAN-CFD software, the finite element simulation has been conducted by series of procedures, such as model building, meshing, loads applying and equation solving, the flow distribution in the sensitive element of the single nozzle and nozzle array fluidic gyro was calculated separately. The results show that the air outlet flow gradient of the array type nozzle increases by 1.1%, the flow velocity difference of symmetrically heat resistance wires in sensitive element increases by 14.3%; the nozzle array structure can effectively improve the resolution of the fluidic gyroscope.

Study on the Pendulum Characteristic of Nature Convection in Dimensional Enclosure

In this paper, the pendulum characteristic of nature convection gas in dimensional enclosure is analyzed by FEM. Using ANSYS-FLOTRAN CFD program, the stream field and the temperature field caused by the point heat source, when the two-dimensional enclosure is inclined, has been obtained by a series of procedure, such as model building, meshing, loads applying and equation solving. The results are as follow: (1)Under the buoyancy lift affecting, the direction of nature convection gas always keeps the vertical upward in two-dimensional enclosure, nature convection gas has the pendulum characteristic. (2)When the dimensional enclosure is inclined, temperature distribution at the several points in dimensional enclosure will change with the tilt angle. The pendulum characteristic can be utilized to measure the tilt angle by the gas pendulum tilt sensor.