基于DSP的动态匀场放大器设计  

Design of Dynamic Shim Amplifier Based on DSP

作　　者：周泽畅[1] 孙宗海[2] 

机构地区：[1]哈尔滨工业大学深圳研究生院自动控制与机电工程学科部,深圳518055 [2]华南理工大学自动化科学与工程学院,广州510640

出　　处：《自动化与仪表》2011年第2期45-49,共5页Automation & Instrumentation

摘　　要：匀场放大器是一种应用于磁共振设备上,对局部高阶磁场进行补偿的高精度电流放大器。随着磁共振设备往高场方向发展,局部高阶磁场的畸变使磁共振成像的伪影变得越来越严重,市场上已有的匀场放大器由于其响应速度过慢,不能对这种伪影进行有效的抑制,而受到了局限。为了改善其在高场应用中的性能,该设计以TI公司的具有高分辨率PWM模块的TMS320F2808 DSP作为主控芯片,设计了一个数字动态匀场放大器,并采用模糊自整定PI作为控制器算法。实验结果表明该动态匀场放大器,具有响应速度快和稳态精度高的特点,能满足高场应用的要求。Shim amplifier is a component in magnetic resonance devices.It is actually a high precision current amplifier used to compensate the local magnetic field.With the development of high-field magnetic resonance equipment,static shim amplifiers has been limited because of its slow response speed.In order to improve its performance in high-field application,this design uses TI＇s DSP provided with high-resolution PWM module to design a digital dynamic Shim amplifiers,and using fuzzy self-tuning PI as the control algorithm.Simulation and experimental results show that the dynamic shim amplifier,with high response speed and high accurate steady state,can meet the high field applications.

关 键 词：动态匀场 高精度PWM BD调制 噪声分析 模糊自整定PI 数字信号处理器 

分 类 号：TN72[电子电信—电路与系统]