【作者】 刘文杰；

【导师】 陈亚珠； 沈国峰；

【作者基本信息】 上海交通大学 ， 生物医学工程， 2012， 硕士

【摘要】 相控信号发生器是P-HIFU系统的核心部件之一。在P-HIFU系统中,相控信号发生器在输入指令的控制下,输出多路具有指定相位的方波信号。这些方波信号经过多谐振功率放大器放大之后,驱动超声压电晶体球形阵列,在指定焦点位置聚焦。本文在研制P-HIFU相控信号发生器的过程中,根据理论计算得出的相位精度对加热焦点参数的影响,对相位信号发生器的需求进行了分析,确定了其性能指标。然后通过对国内外相位信号发生器技术研究现状的分析,讨论并确定了控制接口方案,以及基于FPGA技术的相位信号生成方案。本文设计了相位信号发生器中FPGA固件的架构体系,并使用VHDL代码或现有IP核实现了固件的编码。本文在FPGA固件中加入了嵌入式的MCU,并编写了相应的软件代码,实现了先下载存储相位数据,后顺序输出相位信号的运行模式,该模式实现了加热焦点的快速移动。本文在FPGA的固件中,加入了PCI的IP核,用户可以将相位信号发生器作为PCI插卡,插入到工控机的PCI插槽中使用,实现了实时的加热焦点快速移动的功能。本文完成了相位信号发生器硬件系统的设计,内容包括关键芯片选型、电路原理图设计、以及PCB的制作。本文通过增加硬件监测电路,提高了相位信号发生器的安全性。同时,本文通过硬件电路设计,提高了相位信号发生器的集成度及易用性。最后,本文对于影响相位输出信号精度的关键问题,进行分析并给出了解决方案。最后,通过软硬件联调以及实验检测,验证了本文研制的相位信号发生器实现了预定的性能指标及功能要求,同时具有安全性高、集成度高、易用性高等优点。更多还原

【Abstract】 Phased signal generator is one core components of P-HIFU system. In P-HIFU system, phased signal generator generates multi-channel square wave with specified phase under the controlling of input command. These square wave signal amplificated by the multiple resonant power amplifier then drive the sphere array of ultrasonic piezoelectric crystal to focus on specified position.According to theory of relationship between the phase accuracy and the parameters of heating focus, this paper analysised and identified the phased signal generator. Reference to the status phased signal generator in domestic and foreign, this paper discussed and defined the input control interface type, and selected FPGA-based technology solution to generate phased signal.This paper designed the architecture of FPGA firmware, and used VHDL language or IP core to implement the firmware coding. This paper used embedded MCU to deal with the serial interface communication, achieve the operation mode of―first download phase data and store, then output phased signal in order‖. This operation mode can implement the function of heating focus fast-moving.Adding IP core of PCI interface, the pahsed signal generator development by this can used an one PCI card that insert in the PCI slot, generating phased signal rapidly and implementing the fast-moving function―in real-time‖.This paper completed the hardware system design of phased signal generator, including selection of key chip, schematic design of circuit and PCB production. In this paper, additional hardware monitoring circuit improved the security of the phased signal generator. Meanwhile, the hardware design of this paper has improved the integration of phased signal generator and maked it easy to use.Finally, this paper alalysis and gives solution of key issues on accuracy of output signal. Through hardware and software debug and experimental testing, the phased signal generator developed by this paper make with the intended performance and functional requirements, and also has advantages of high security, high integration, easy to use.更多还原