Ming Ming Ji

Three-Dimensional FEM Analysis of Effect of Acceleration on Airflow Level Posture Sensor

Using ANSYS-FLOTRAN CFD program, the finite element simulation is conducted by means of a series of procedures, such as three-dimensional model building of airflow level posture sensor, network modifying, loads applying equation solving, the flow field in three-dimensional hermetic chamber of sensitive element of airflow level posture sensor in different acceleration and inclination is Calculated, The numerical results show that for the sensor of airflow level posture sensor, the effect of acceleration and inclination is similar. Both of them can change the flow field of sensor, and will output a corresponding voltage. The simulation result of three-dimensional modeling is more comprehensive and accurate, which provides more reliable basis for practical research of the airflow level posture sensor.

Three-Dimensional FEM Analysis of the Gas Pendulum Characteristic for Airflow Level Posture Sensor

Using ANSYS-FLOTRAN CFD program, the finite element simulation is conducted by a series of procedures, such as three-dimensional model building of airflow inclination sensor, network modifying, loads applying and equation solving. The flow field in three-dimensional hermetic chamber of sensitive element of airflow level posture sensor is calculated, FEM analysis has been obtained. The numerical results show that 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, and 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 level posture by the airflow level posture sensor.

Three-Dimensional Modeling and Simulation for Airflow Inclination Sensor

Using ANSYS-FLOTRAN CFD program, the finite element simulation is conducted by a series of procedures, such as three-dimensional model building of airflow inclination sensor, network modifying, loads applying and equation solving. The flow field caused by the two heats in three-dimensional hermetic chamber of sensitive element of airflow level posture sensor is Calculated, FEM analysis has been obtained. The numerical results show that compared with two-dimensional modeling, the simulation result of three-dimensional modeling are more comprehensive and accurate, which provides more reliable basis for practical research of the airflow inclination sensor.

Three-Dimensional FEM Analysis of Sensitive Mechanism of Airflow Level Posture Sensor Based on Thermoelectric Coupling

Using ANSYS program, the finite element simulation based on thermoelectric coupling is conducted by a series of procedures, such as three-dimensional model building of airflow level posture sensor according to the actual size of the proportion, network modifying, loads applying and equation solving. The sensitive mechanism of airflow level posture sensor is explained by finite element method. The numerical results show that compared with two-dimensional modeling, the simulation result of three-dimensional modeling and thermoelectric analysis methods are more comprehensive and accurate, which provides more reliable basis for practical research of the airflow level posture sensor.

Study on the Airflow Level Posture Sensor Based on Fluid-Solid Coupling

Using ANSYS program, the finite element simulation based on Fluid-Solid coupling is conducted by a series of procedures, such as three-dimensional model building of airflow level posture sensor according to the actual size of the proportion, network modifying, loads applying and equation solving. The flow field in three-dimensional hermetic chamber of sensitive element of airflow level posture sensor is calculated. The numerical results show that: 1) The velocity difference of air flow at two heat source changes with the tilt angle, the difference between airflow velocity increases with the increase of the tilt angle. 2)Compared with two-dimensional modeling, the simulation result of three-dimensional modeling and fluid-solid analysis methods are more comprehensive and accurate, which provides more reliable basis for practical research of the airflow level posture sensor.

Rearch of Data Interpolation in Airlevel Posture Sensor

The method of interpolation was used in the process of software compensation of temperature in order to improve the environmental performance of air level posture sensor. Two algorithms including Lagrange interpolation and piecewise linear interpolation were calculated and compared in Matlab software, and then the optimization scheme could be achieved. The result showed that although the curse of Lagrange interpolation included all the given data positions, the Runge phenomenon in polynomial interpolation made the accuracy of interpolation lower. Piecewise linear interpolation reflected the relationship between environment and zero voltage more accurately. Piecewise linear interpolation not only can be used to improve the accuracy of software compensation of air level posture sensor.

Research about Air Level Posture Sensor

Sensitive principle of air level posture sensor is introduced and test to the actual manufactures sensor is carried on. The test result indicates that the temperature’s influence to the sensitivity is suppressed basically; the operating temperature scope expands from the normal temperature to 30°C; the resolution surpasses over 0.1°; misalignment of air level posture in full scale scope is smaller than 1%，measuring range the angle of tilt may achieve to 20°.

Signal Process Technology of Omni-Directional Level Posture

Micro mechanical airflow level posture sensor, combined with micro mechanical skill and air pendulum, the volume is small, the structure is compact, the craft is simple and uniformity of sensitive component is good. But it can be only sensitive to tilt posture around the specific sensitive axle. In order to realize the omni-directional survey, this article utilizes the MEMS tilt-sensitive component to withdraw omni-directional and carries on sensitivity compensation of omni-directional signal. The results show that: resolution is better than 0.1 °; nonlinear is small than 1.2%; range of angle measurement is from 0 °to360 °, realizing survey of omni-directional level measurement.

Linearity Compensation of Air Level Posture Sensor

In order to improve linearity of output signal of air level posture sensor, this article do the research about linearity to output signal based in the operation function of single chip of MSC1214, uses the ORIGIN software to process experiment data to get the linearity curve. The result indicates that misalignment of sensor drops to ≤1% in full scale scope, linearity between output voltage and the input angle has the enormous improvement, depressing the influence caused by angle approximation and improving the measurement accuracy of air level posture sensor.

Temperature Software Compensation of Air Level Posture Sensor

Based on operation computation of signal chip MSC1214, Output signal processing of air level posture sensor is carried on, including temperature –zero voltage compensation, temperature-sensitive voltage. The results show that the change quantity of sensitivity drops to ≤1%; the operating temperature scope expands from the normal temperature to 30°C; in this temperature range, the change quantity of zero voltage drops from ≤0.23V to ≤0.01V, depressing the influence caused by temperature and improving the measurement accuracy of air level posture sensor.