【作者】 刘杰；

【导师】 郝明晖； 郝双晖；

【作者基本信息】 哈尔滨工业大学 ， 机械设计及理论， 2010， 博士

【摘要】 数控装备是典型的机电系统,是装备制造业的核心。为达到数控装备高速和高精度的发展目标,需要对其进行机电一体化的全局最优化设计,这要求NC指令周期和伺服系统的机械环周期、电流环周期完全同步。本文旨在研究交流伺服系统机械环和电流环的同周期控制问题,使其获得更加优越的性能,并为数控装备全同周期的实现提供同周期伺服系统平台。为证明同周期控制的优越性,本文建立了交流永磁同步电机d-q坐标系下的数学模型。对比同周期和不同周期两种控制结构的控制效果,同周期控制系统波动极小,更接近于理想曲线。推导了同周期控制和不同周期控制系统的闭环传递函数,同周期系统传递函数相对阶数最低,最稳定。根据控制系统模型设计了软件仿真系统平台,设置机械环和电流环在不同周期和同周期控制情况下,分别进行速度控制仿真。仿真结果表明,同周期控制可更有效地抑制负载转矩波动。针对同周期控制将会引发的电流采样噪声、速度分辨率低以及计算量大等问题,提出了有效解决途径——用全整数运算来进行控制算法设计,设计全整数的电流环状态观测器和机械环状态观测器。针对实现同周期控制需要解决的计算量大的问题,提出了全整数控制算法设计的基本规则。为获得高效高精度的矢量变换算法,简化了矢量变换公式,设计了可以快速地获得高精度正弦和余弦值的查表算法。针对三相脉宽调制中母线电压不能被充分利用的问题,设计了电压矢量中心点平移算法,证明了其有效性和无方向误差。根据同周期控制交流伺服系统电流环模型和机械环传递函数,设计了伺服控制主程序流程图和同周期控制程序流程图和系统软件。研制了包括主控板、功率板和电源板在内的系统硬件。为解决同周期控制中的电流采样噪声问题,推导了低通滤波器的递推公式和电流环状态观测器的递推公式,并提出了极点选取原则。设计了电流环调节器,并讨论了控制参数取值方法。建立了电流环的仿真模型和状态观测器的仿真模型,通过电流控制仿真确定了观测器极点选取和系统控制参数范围,并验证了观测器的有效性和优越性。编写了电流低通滤波器和电流环状态观测器的程序模块,在试验平台上进行了电流控制试验,试验结果证明状态观测器能够更有效地抑制电流采样噪声,达到更高的电流响应频率。针对同周期控制中,机械环频率高所导致的速度分辨低的问题,推导了速度数字低通滤波器的递推形式,并设计了机械环状态观测器,给出了观测器的收敛条件,并进行了极点选取。在电流环仿真模型的基础上,搭建了机械环仿真模型,对机械环和观测器进行了仿真调试。控制仿真结果证明了机械环状态观测器的有效性。编写了速度滤波器程序模块和机械环状态观测器程序模块,进行了速度控制试验。试验结果证明,应用了状态观测器的系统具有较高的响应速度和稳定性。针对高速电机控制中的高频电流控制问题,分析得出PWM频率不小于电流频率6倍的结论。针对当前位置检测器件无法在高速情况下正常工作的现状,提出了高速电机控制对位置检测器件的要求。本文系统中单对极磁性编码器的特性符合高速电机控制的要求。针对高速电机矢量控制中电压矢量变换的角度误差较大的问题,提出了超前补偿方法。针对编码器角度上报方式造成的角度反馈滞后问题,推导了角度反馈滞后量计算公式。设计了4对极20,000r/min永磁同步电机,用同周期伺服控制器对其进行了高速控制试验,高速电机的最高控制转速达到了22,000r/min。高速电机控制试验的成功,验证了本文研制的同周期控制交流伺服系统,可在PWM频率与电流频率达到极限比例的情况下进行高频电流控制和电机伺服控制,充分证明了此伺服系统具有非常优良的控制性能。更多还原

【Abstract】 CNC equipment is a sort of typical electro-mechanical system, which is the core of equipment manufacturing industry. To realize the performance of high-speed and high-precision, the whole optimal design based on the mechanotronics is necessary, and it requires the cycle of NC instruction to be the same with the cycles of machine and current in the servo system. The thesis purposes on the uniform cycle control of machine-loop and current-loop to get the better performance for the AC servo system, and provides a uniform cycle servo system platform to achieve the integrate uniform cycle control in the CNC equipment.In order to validate the superiority of uniform cycle control, the math model of permanent magnet synchronous motor (PMSM) in the d-q coordinates is built. Compared the control effects of the uniform cycle control structure with the ones of the different cycle control structure, the fluctuation of the uniform cycle control is extremely unconspicuous, and the curves of output are more ideal. The transfer functions of uniform cycle control system and different cycle control system are derived respectively in this thesis. The transfer function of uniform cycle control system is provided with the lowest relative degree and the best stability. According to the models of the control system, the simulation platform is designed. Based on the simulation platrom, the velocity control is simulated with the uniform cycle control and the different cycle control. For the problems of current sampling noise, low velocity resolution and burdensome calculation based on the uniform cycle control, the effective solutions are proposed, which include the control algorithm with the integrate int calculation and the integrate int observer of current-loop and machine-loop.For the sake of realizing the uniform cycle control, a mass of calculation is needed to be carried out. In this thesis, the regulation based on the integrate int computing is proposed. To obtain the high-speed and high-precision vector transformation algorithm and simplify the vector transformation formulation, the algorithm of table looking-up which can get high-precision sine and cosine amount rapidly is designed. For the problem that the busbar voltage cannot be utilized sufficiently in 3-phrases PWM control, the algorithm of voltage vector center point translation is put forward, and the validity and precision are verified. Basd on the transfer function of current-loop model and mechanical-loop model in the uniform cycle system, the flow chart of main program for servo control and uniform cycle control are designed. And the control software of system is develped. The hardwares which include control board, power board and power supply board are also designed and developed.To solve the problem of current sampling noise in uniform cycle control system, the recurrence formulas of the low-pass filter and the observer in current-loop are achieved, and the regulation of pole’s selecting is discussed. Also, the adjustor in current-loop is designed and the method of control parameters’selceting is discussed. The simulation models of current-loop and observer are established, and the observer poles’selection and control parameter’s range are acquired from the current control simulation, and the superiority of the observer is validitied. And then, the program models for current low-pass filter and current observer are built. Taking the current control experiment on the experimental platform, the results show that the observer can press the current sampling noise effectively and gain the higher current response frequency.In the uniform cycle servo system, the high machine-loop frequency brings the problem of low velocity resolution. The recurrence of low-pass digital velocity filter is derived, the convergence condition is proposed, and the pole’s selection is dicussed. Based on the current-loop simulation model, the machine-loop simulation model is built, and the simulations of machine-loop and observer are carried out. The simulation results show the validity of the mechanical observer. Also, the velocity filter and machine-loop observer program modules are built, and the velocity control experiment is achieved based on the experimental platform. The experimental results indicate that the system adopting observer in current-loop and machine-loop is of higher response and stability.For the high frequency current control in the high-speed motor, the thesis achieves the conclusion that the frequency of PWM is requied to be 6 times lower than the current frequency. The present position detecting device cannot achieve nice effect in the high-speed condition, and the requirement for the position device in high-speed motor control is proposed. The characteristics of the single pole magnet encoder in the thesis meet the demand of high-speed motor control. For the problem that the angle errors exist in voltage vector transformation, the advancing compensation principle is put foward. Also, the method of angle uploading in encoder induces the delay of angle feedback, and the delay calculation formula of angle feedback is derived. Then, the 4-poles PMSM (20,000 rpm) was designed, and the motor has achieved the highest speed of 22,000 rpm based on the uniform cycle servo control equipment.The successful application in the high-speed motor control indicates that the uniform cycle servo system in this thesis can achieve the high frequency current control and servo control in the condition of that the frequencies of PWM and current get their ultimate proportion. It bears out that the servo system is of the excellent control performance.更多还原