摘要
在核磁共振(NMR)实验中,样品旋转能够有效消除XY方向磁场的部分不均匀性,从而提高信号分辨率。在商用NMR谱仪中,一般采用PID算法进行待测样品的旋转控制。由于被控对象具有一定的非线性,存在着调节时间较长,稳定后存在误差等缺点。针对该现象,在Varian 500 MHz波谱仪气路系统的基础上,设计一套新的控制电路,在控制方法上引入了模糊PID控制,经过多次实验调试、优化处理,定制了适用于NMR谱仪气控系统的模糊参数隶属函数和模糊规则,设计出一种模糊自适应PID控制算法。结果表明,本系统较原系统稳定时间缩短了约30 s。在相同的实验环境下采样,本系统得到半高宽均值为1.27 Hz,信噪比为2293,优于Varian气控系统采样所得的结果,增强了旋转控制的鲁棒性,加快了响应速度和稳定速度,具有较高的应用价值。
In commercial nuclear magnetic resonance（NMR） spectrometer,a PID controller is generally used to regulate the rotation of samples.There are some faults such as long adjustment time,steady-state error because of the nonlinear character of the object.To improve system performance,a new pneumatic controller system was proposed by using self-tuning fuzzy proportional-integral-derivative（PID） controller to replace the original pneumatic system based on PID.The adjustment time of proposed controller is about 30 s shorter than that of Varian.The result of the experiment under the same environment shows that the half-height width after applying the proposed controller is 1.272 better than 1.396 of Varian and S/N is 2293.114 better than 2245.48 of Varian.The experiment result shows that the proposed controller is robust,quicker response and has great value for application and research.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2011年第4期506-510,共5页
Chinese Journal of Analytical Chemistry
基金
国家科技支撑计划(No.2006BAK03A22)
国家博士后基金(No.20090460750)资助
关键词
核磁共振波谱仪
气控系统
模糊PID
样品旋转
自适应
Nuclear magnetic resonance spectrometer
Pneumatic system
Fuzzy proportiona-lintegral-derivative controller
Spin
Self-tuning
作者简介
E-mail：hfliu@xmu．cdu．cn
