伺服控制软件中内置数控指令模块实验研究

提出在交流伺服系统软件中,对内置逻辑功能模块和NC指令模块采用整数运算以提高处理速度,使其与底层控制程序同周期执行.对NC指令模块几个模式进行了研究和设计;实验结果证明此方案切实可行.此项研究了实现了CNC系统和伺服系统底层的一体化,提高了系统的集成度和可靠性,大幅度缩短了指令周期,保证了控制精度,降低了系统硬件成本.     

交流伺服直线位移平台高速定位控制

对直线位移平台的高速定位控制中,采用传统PID控制和低通滤波处理方法很难同时获得良好的指令跟踪特性和抗干扰生能.针对此不足,在建立了交流伺服电机控制模型的基础上,根据交流伺服硬件系统设计了三闭环PID控制结构.同时,为提高高速定位控制性能,设计出前馈控制和二自由度控制结构,并与传统PID控制进行了对比仿真,结果表明这种控制方法可以有效提高系统的指令跟踪特性和抗干扰性能.最后,设计了试验系统,对直线位移平台进行了高速定位控制试验,验证了此方法具有良好的控制性能.     

交流伺服系统中全整数状态观测器的研究

交流伺服控制中采用数字低通滤波可以抑制电流反馈噪声,提高速度反馈分辨率,但同时会带来反馈信号的相位滞后,将直接影响响应速度.引入电流环和速度环的状态观测器提高系统性能.为解决状态观测器中采用传统浮点数运算时,因自动下溢出产生误差的问题,提出全整数运算算法提高控制精度.对系统模型进行仿真对比分析后,设计了试验系统,并通过试验对比了采用全整数运算状态观测器与数字低通滤波器的系统性能,验证了这种状态观测器控制系统的优越性.     

永磁直线交流伺服系统机械环的研究

在永磁直线交流伺服系统中,机械环和电流环的控制周期相同,可以提高系统的运动精度,这就要求机械环的控制频率要大幅度提高,但编码器的分辨率一定,采样频率越高,速度反馈的分辨率将降低,反过来又影响系统控制精度和速度平稳性.基于此问题在在机械环中引入状态观测器,推导了机械状态观测器的方程,解决速度反馈延时滞后对系统精度的影响.对传统的机械环和加入状态观测器进行仿真,结果证明了引入机械环状态观测器可以提高系统的抗干扰能力,从而保证了位置控制精度.     

A novel absolute displacement detecting magnetic sensor

A novel magnetic grating based on calibration was proposed.Two tracks,look-up track and index track,were used to realize absolute output.Magnets of look-up track were magnetized according to N-S-N-S,and magnetic field was sensed by 6 linear Hall sensors.Three signals whose phase shift is 120° were obtained through difference,and the offset of magnetic head in a signal period could be obtained by look-up table;Magnets of index track were magnetized according to pseudorandom binary sequence.Hall sensors were used to get the absolute offset of the signal period to which the magnetic head is belonged.The magnetic grating was calibrated using a higher resolution optical grating:output of optical grating and signals from magnetic grating were sampled at the same time and transmitted to computer,the relation between them could be got and stored in MCU for looking-up.The displacement was got according to Hall signals while in working state.A magnetic grating prototype was made,and it could realize absolute detecting in 2048 mm and the resolution could achieve to 0.001 mm.Its structure is simple,cost is very low and it is suitable for mass production.