【作者】 戚嘉兴；

【导师】 曾庆双；

【作者基本信息】 哈尔滨工业大学 ， 控制科学与工程， 2010， 硕士

【摘要】 高精度测试转台是一种用来对惯导系统和惯性仪表进行误差模型标定的设备。测试转台性能的优劣直接关系到测试试验的可靠性和精度,是提高航空、航天产品和武器系统的精度和性能的基础。随着航空、航天技术的迅猛发展,对导航和制导设备的性能和精度的要求不断提高,相应地需要精度更高测试转台。然而,转台低速性能的提高却受到以摩擦力矩为主的扰动力矩的影响,而摩擦力矩的减小又受到工艺水平及实验经费等条件的限制。因此,从控制方法上设计能克服摩擦影响的控制律,减弱或消除摩擦影响从而达到高精度控制,对研制结构简单且性能优良的转台具有重要的理论意义和实际应用价值。针对本课题,主要完成了以下工作:首先介绍了国内外转台低速性能的研究现状,着重分析了前人在转台低速性能影响方面的研究情况;针对摩擦补偿问题,介绍了常用的摩擦模型以及摩擦补偿研究方法。在转台基本结构的基础上,针对具体系统建立转台的数学模型;介绍了现在转台常用的PID控制方法,并分析了其中各参数对系统性能的影响。针对转台低速性能问题,深入分析了影响转台低速性能的主要因素,即测角系统误差、电机波动力矩和摩擦干扰力矩,研究了这些因素对系统低速性能的影响;分析了加速度反馈抑制外界干扰的原理,在此基础上设计了基于滤波器/观测器的加速度反馈控制律,特别针对小幅值低频正弦输入信号和低速斜坡信号进行了仿真分析和研究。理论和实验分析表明,系统跟踪误差是与给定信号同频率的谐波叠加的形式,在此基础上分析了前馈控制和自适应控制的特点,将两者进行有机结合为自适应前馈控制;分析了转台自适应前馈控制原理,设计出相关控制律,并通过仿真证明了方案的正确性。以某单轴转台的研制为契机,设计了测角系统和接口硬件电路。针对光栅使用过程中出现的偏心和斜角误差进行了分析,实验验证了误差补偿的正确性,提高了测角精度。设计实现了工控机控制软件的编写,完成了自适应前馈控制算法的编写和实验。实验结果表明该方法是可行有效的。更多还原

【Abstract】 Test turntable with high precision is a kind of significant apparatus for model calibration of inertial navigation systems and inertial instruments. The quality of test turntable determines the reliability and accuracy of experiments and is the foundation upon which the precision and performance of aeronautics and astronautics products and weapon systems is guaranteed. With the rapid progress of aeronautics and astronautics technologies, more excellent performance and accuracy of navigation and guidance is demanded, which in turn need improvement of the test turntable. However, the enhancement of the turntable in performance is limited by the disturbing torque, especially friction torque, while the reduction of friction is limited by technological level and experimental funds. Therefore, devising interrelated control laws to eliminate and compensate friction effect and in turn achieving high precision control contribute apparent theoretical significance and applicant value for the research of turntable with simple structure and high precision. For the problems mentioned above, relative researches are finished as follows:First, the research situations of turntable with low velocity are introduced and especially in the aspect of friction effect for turntable. Aiming at the problem of friction compensation, friction models in common use and compensation methods are presented. Based on the structure of turntable, the control model is constructed and linearization for actual system is finished, which in turn achieve the mathematic model of turntable. Also, the PID control law in tradition for turntable is recommended and the influence of parameters in PID for system is analyzed.For the low velocity performance of turntable, research is carried on about main factors which show clear effects on the low velocity performance, such as angel measuring error, disturbing torque of motor and friction torque, and relative researches are completed by simulation and experiments. In foundation of the theoretical analysis for restraining environmental disturbance by acceleration negative feedback, the control law for acceleration negative feedback which based on filter and observer are designed, and more simulations and researches are carried out, especially for sinusoidal signals with low frequency and ramp signals with small slope.By analyzing theoretical simulation and actual experiment, the tracking error of system is a series of signals with the same frequency as the order signal, based on which, the character of forward-back control method and self-adaptive control method are analyzed. In turn, self-adaptive and forward-back control law is conbined. The simulation indicates that this method performs apparent control capability in restraining the effect of friction torque for turntable performance in low velocity.Based on the research of a kind of turntable, hardware of angel measuring system and interface circuits is devised. For the decentration and pitched error in the process of grating application, relative researches are carried out, and of which, the correctess is poroved by experiment. Also, the software of industrial control computer is accomplished and the self-adaptive and forward-back control law is tested by turntable with single shaft. Finally, the experiment results significantly suppose the validation of the control law designed.更多还原