基于Kalman滤波的田间导航车辆定位校正方法研究

以装载了RTK-DGPS导航系统的KUBOTASPU-68水田插秧机为试验平台,以姿态测量系统提供载体姿态信息,研究农业机械导航的姿态校正方法。在分析车载GPS倾斜误差产生原因基础上,提出了采用多传感器联合测量载体姿态角以提供校正信息。采用MEMS传感器集成模块ADIS16355作为惯性测量单元,卡尔曼滤波实现传感器信息融合以计算姿态角,设计了姿态测量系统。阐述了两种传感器融合测量实时姿态角的算法,基于ARM7Cotex-M3微处理器设计了姿态测量系统硬件。     

Analysis of flow characteristics in thermal-bubble actuated diffuser-nozzle valveless micropump

Based on the different flow resistance characteristic of diffuser/nozzle at the bubble growth and condensation stage, the flow characteristics of thermal-bubble actuated valveless micropump under different ratio of heating, driving frequency and diverging angle and different heating power are numerically investigated. Evaporation and condensation processes are accomplished by Volume of Fluid (VOF) multiphase flow model and User Defined Functions (UDF) interface. The results reveal that with the same ratio of heating time, the volume flow rate increases at first and then decreases with the increasing driving frequency. The micropump has a maximum flow rate of 5.87 μL/min when the driving pulse is 250 Hz at 10% heating ratio. The volume flow rate increases at first then decreases with the enlarging diverging angle when keeping the aspect ratio constant, and it will reach the maximum when the diverging angle is 14°, and it has a higher pressure difference between the diffuser and the nozzle. The average velocity at the diffuser neck is always greater than the nozzle during the entire driving period, the pumping flow rate presents a trend of increasing at first and then flatting with the increasing heating power.     

海参捕捞装置导航中低成本陀螺仪的降噪研究与试验

针对MEMS陀螺仪输出信号中含有的随机漂移噪声造成海参捕捞装置惯性导航精度明显下降的问题,采用时间序列分析法和Kalman滤波算法,对MEMS陀螺仪随机漂移噪声的削减问题进行研究。以MEMS惯性测量单元的实测数据和三维电子罗盘测量的姿态角为样本,对本研究的低成本陀螺仪的降噪效果进行测试,试验结果表明:1)经过降噪处理后的陀螺仪随机漂移信号的方差比陀螺仪原始采样信号的方差降低1个数量级,显著改善了陀螺仪随机漂移数据的精密度;2)以高精度三维电子罗盘实测的姿态角作为参考基准,将降噪后的陀螺仪随机漂移数据导入捷联惯导姿态更新算法程序,在300s时间内,解算出的俯仰角、横滚角和航向角的均方根误差RMSE全部小于1°;与降噪前相比,相应的俯仰角、横滚角、航向角的RMSE分别降低了170.5、97.6和42.5倍,明显提高了惯性导航精度。     

基于AR模型的MEMS陀螺误差补偿方法研究

针对MEMS(Microelectro Mechanical Systems）陀螺具有成本低、体积小但误差较大的问题,探讨MEMS陀螺的误差补偿方法。基于AR模型方法,采集MEMS陀螺原始信号,对原始信号进行预处理,利用预处理后的数据建立陀螺的AR(Auto Regressive)模型,辨识出模型参数。利用该模型对陀螺信号进行误差补偿,计算出陀螺的较精确值。通过对某MEMS陀螺误差补偿的静态和动态试验表明,提出的方法能够有效地减小误差,提高陀螺的测量精度。     

基于MEMS加速度传感器的手语识别系统

论述了基于高灵敏度、高准确度MEMS传感器的手语识别系统。该系统可识别聋哑人手形的变化,并将中国的手语拼音翻译成语音由麦克风播放出来。介绍了该系统的硬件设计、传感器选择及软件程序设计。     

微电子机械技术的发展研究

文章将重点介绍微电子机械技术的发展与现状,分析和探讨这一新机械技术的影响和意义,并总结出微电子机械技术发展所面临的的问题,并提出相应的策略和解决办法,从而为微电子机械技术的发展作出铺垫。     

Numerical simulation of hydrogen air combustion in meso scale IC engine

The burning rate of hydrogen air pre mixture on meso scale is mainly determined by its chemical reaction rate. So a Laminar Finite Rate Model, the gas phase reaction mechanism for the combustion of hydrogen air mixture which consists of 19 reversible elementary reactions and the dynamic mesh method are adopted to simulate the combustion of hydrogen air mixture in a meso scale IC engine which operates a quasi gas power cycle under ultrahigh combustion load. The combustion of hydrogen air mixture on meso scale in the micro combustion chamber with moving boundary can be stable. The complete thermodynamic process of heat addition, internal energy increasing, and a boundary work output producing during expansion can be perfectly achieved in the closed combustion system of the meso scaled IC engine igniting the hydrogen air mixture by wire surface of high temperature. However, running parameters such as cycle period, initial pressure and fuel/air ratio have complex effects on the hydrogen air combustion of micro closed container with moving boundary.     

MEMS传感器技术在汽车上的应用研究与展望

为了满足汽车电子化、智能化的需要,越来越多的MEMS(微机电系统)传感器应用到汽车上。本文对主要的几种汽车MEMS传感器的应用状况和研究现状进行简述,并且对压力传感器和微加速度计的设计缺陷进行研究。同时,结合MEMS传感器的特点和车载传感器的要求,对汽车MEMS传感器的发展提出几点建议和展望。     

C8051F320在的数字可调光衰减器设计中的应用

为了在光通信中实现光信号的衰减,采用微处理器C8051F320和AGILTRON公司的MEMS型EVOA元器件,实现了一种结构简单,低成本的可调光衰减器。本可调光衰减器由EVOA控制电路、液晶显示电路、USB接口电路和UART接口电路组成。通过实验测量和批量应用于生产,表明本可调衰减器工作可靠,有良好的精度。     

Dynamic Lubrication of Micro Gas Bearings at an Ultra High Speed

Micro bearings of Power MEMS are usually designed to work at an ultra high speed more than 10~(6) r/min in order to improve their specific energy. So the dynamic lubrication of micro gas bearings at an ultra speed is researched. First the micro structural characteristics of micro gas-lubricated bearings are investigated, and a method to caculate the load-carrying performance of micro dynamic gas-lubricated bearings is put forword. Then the designs of two typical micro dynamic gas-lubricated bearings that are used in micro gas turbines are vertified. Moreover, the parameters affecting the load-carrying performance of micro dynamic gas-lubricated bearings are analysed.