【作者】 吴敏；

【导师】 王毅；

【作者基本信息】 哈尔滨工业大学 ， 控制理论与控制工程， 2011， 硕士

【摘要】 为了满足新一代高精度惯性传感器的测试要求,需要研制更高精度的惯性测试转台。本文以测角精度为0.5″的惯性测试转台为背景,以实验室某单轴原型转台为实验平台,重点研究了圆光栅测角系统的测角精度和决定速率平稳性的摩擦力矩补偿方法。圆光栅传感器比感应同步器具有更高的测量精度。圆光栅测角系统采用双读数头对径安装的结构,有效的减小了光栅圆环安装偏心对测角误差的影响。为了进一步减小测角误差,采用光电自准直仪和23面棱体对圆光栅传感器的轴系测角误差进行了离散标定。对误差信号进行谐波分析,然后根据计算得到的谐波系数,用软件进行反向谐波补偿,使得补偿后的测角精度达到0.5″。在圆光栅测角系统提供了高精度角度信号的基础上,在单轴原型转台上进行转台控制系统实验。建立转台控制系统的数学模型,设计串联校正控制算法,将控制算法在DSP(Digital Signal Processor)上实现。在原型转台上测试了转台的速度较高的运动状态下的性能指标,符合设计要求,而原型转台在低速状态下产生了低速爬行,低速平稳性差。转台转轴上的摩擦力矩是导致低速爬行的主要原因。本文研究了通过摩擦力矩补偿的方式来改善转台低速平稳性的方案。为了实时地跟踪摩擦力矩的变化,精确地对摩擦力矩进行补偿,实际了基于LuGre摩擦模型的自适应摩擦补偿算法,并通过仿真验证了算法的有效性。更多还原

【Abstract】 In order to meet the needs of testing the new generation high precision inertia sensors, inertia testing turntables of higher precision have to be manufactured. This paper takes inertia testing turntable-whose angular measurement accuracy is asked to be 0.5 arc sec-as the background, and takes the single-axis prototype turntable in our lab as the experiment platform, and has mainly researched the circular grating angle measurement module’s angle accuracy and friction torque compensation technology which have great influence on low-speed rate stability.Circular grating angle sensor has higher precison than inductosyn. The circular grating angle measurement module installed two opposite-in-diameter readheads, which has efficiently reduced the error introduced by scale eccentricity and distortion. In order to further reduce the angle measurement error, a discrete calibration of angle measurement error was made by a photoelectric auto-collimator and a 23-face metal polyhedron. Through harmonic anlysis of the error signal by FFT (Fast Fourier Transform), we got the harmonic coefficients. A software- based harmonic compensation was made, and the finally angle accuracy reached 0.5 arc sec.After the circular grating angle module giving high precision angle signal, turntable control system experiments were made at the single-axis prototype turntable. First, the turntable’s mathematic model was made, and a series adjustment algorithm was proposed, and finally the algorithm was realized on a Digital Signal Processor (DSP). The experiments on the prototype turntable have demonstrated that in middle and high rate, the turntable works well and meet the performance requirements. Howerver, in low rate, the turntable emerged stick slip phenomenon, and the low rate stability is poor.The friction torque on the turntable’s shaft is the main reason for stick slip phenomenon. The paper has investigated the way of friction compensation to improve low rate stability. In order to track the friction torque in real-time, and make precision friction torque compensation, an adaptive friction compensation algorithm based on LuGre model was proposed, and simulation experiment has illustrated the algorithm’s validity.更多还原