【作者】 周鸣；

【导师】 万健如；

【作者基本信息】 天津大学 ， 电力电子与电力传动， 2007， 硕士

【摘要】 惯性导航装置因具有机动性、保密性、抗电磁干扰能力强及不受地形限制的特性,在军用导航仪表中占有重要地位。捷联式挠性陀螺寻北仪能为军车提供基准定向和导航数据。由于寻北仪需要的控制信号较多,且时序关系复杂,故选用由DSP和FPGA组成的嵌入式控制器作为寻北仪的解算和控制单元。DSP选用TI公司F2812芯片,它运算速度快、程序存储器容量大、具有多个专用功能模块,主要负责解算和控制职能。FPGA选用XILINX公司XCS-20XL芯片,FPGA主要负责分频与时序控制。数字再平衡回路是陀螺仪的控制回路和测量回路。经过预处理的陀螺信号被送往专用的16位A/D转换芯片,DSP将转换后的数据读走并解算出相应的施矩值。捷联状态下,陀螺仪力矩器必须通过大电流,才能实现再平衡功能。设计由MOS管搭建的H桥施矩电路,并在FPGA中编写了施矩控制程序。在此基础上,进行了施矩电路线性度实验和陀螺仪常温漂移实验。寻北仪采用的四位置寻北算法,具有消除陀螺仪漂移及获取纬度信息的优势。DSP控制程序设计是寻北仪系统中的核心部分,其中寻北仪的控制与伺服功能都在中断服务程序中完成。寻北仪单位置重复性实验和全周寻北实验都取得了较为满意的结果。挠性陀螺仪因其固有的结构特性,两个轴的输入输出信号会产生交叉耦合。若要进一步提高寻北精度或获取更精确的导航数据,则需对挠性陀螺仪进行解耦。针对转子偏角耦合与输出电流耦合采用对角线矩阵方法分别进行解耦。因受军工项目交付时间限制,解耦研究仅进行了公式推导,将其应用于捷联式寻北仪设计中将是下一步工作的重点。更多还原

【Abstract】 As inertia navigation unit is mobile, secret, free of electromagnetism interference and topographic condition,it occupies a important place in military navigation meters. Strap-down flexible gyroscope north seeker provides direction and position, navigation data for the military vehicle.Because control signals of north seeker are numerous and complex in time sequence, we use embedded controller, which is composed of DSP and FPGA, as the calculation and control unit for the north seeker. F2812 DSP chip made by TI Company, has short instruction cycle, great On-chip Flash ROM, multiple special function modules and it is responsible for the calculation and control functions. XCS-20XL FPGA chip made by XILINX Company, is responsible for the frequency division and some control functions.Digital rebalance loop is the control and measurement loop of the gyroscope. Gyro signals, which have been preprocessed, are sent to a special 16-bit A/D converter, and then DSP reads and deals with the converted data to calculate the corresponding moment data. Under Strap-down status, the moment coils of gyro should pass high current to meet the rebalance demand. We design H bridge moment circuit composed of MOS tubes, and compile the moment control program in FPGA. Base on these preparations, we carry out moment circuit linearity experiment and gyroscope room temperature drift experiment.Four positions north seeking algorithm has the advantages of eliminating gyro drift and obtaining latitude information. DSP control program is the core part of north seeker design, and the control and servo function are implemented in the interrupt service routine. The experiment of north seeker single position repeatability and full circular north seeking achieve satisfying results.Because of flexible gyro’s inherent structure characteristic, the input and output signals of the X-axis and Y-axis are coupling. In order to improve north seeking precision and obtain more accurate navigation data, we should use decoupling control on flexible gyro. Diagonal matrix decoupling method is used both on rotor deflection coupling and output current coupling. Due to the lead time of military project, we only make formula derivation on decoupling, applying it to the design of Strap-down north seeker is the major step for the further research.更多还原