面向悬浮光力系统的集成化反馈控制器研究

An integrated feedback controller for levitated optomechanical systems

关键词:  反馈控制器  集成化  悬浮光力系统  数字锁相环  力学传感

Key words:  Feedback controller  Integrated  Levitated optomechanical system  Digital phase-locked loop  Mechanical sensor

摘要:

悬浮光力系统具有高灵敏度、高稳定性和低耗散等特点，有望发展成为新型高性能力学传感器。针对目前悬浮光力系统存在的反馈控制器兼容性差、软硬件成本高、集成度低等问题，提出了一种兼容多种反馈控制模式的软硬件设计方案，并研制了一套高度集成的反馈控制器，在160 mm×170 mm×42 mm的尺寸上集成了六通道模数/数模转换器、滤波器、现场可编程门阵列+微处理器(FPGA+ARM）等功能模块，并且开发了基于数字锁相环和比例积分微分(PID）控制器的控制算法，最终在同一套硬件系统上实现了跨尺度微粒的运动信息采集和反馈控制，以及数十赫兹至亚兆赫兹的感知带宽。实验结果表明，该集成反馈控制器能够实现超高真空(10-6 Pa量级）下亚微米及微米尺度微粒的稳定悬浮和运动控制。在扩展系统感知带宽的同时减小了整体体积，为悬浮光力传感技术的器件化奠定了基础。

Abstract:

Levitated optomechanical systems with excellent sensitivity, high stability and low dissipation are expected to become new high-performance mechanical sensors. But current feedback controllers for levitated optomechanical systems have issues of poor compatibility, high cost and low integration. A hardware-software scheme compatible with multiple feedback control modes is showed here. And a highly integrated feedback controller is developed, which contains six-channel analog-to-digital/digital-to-analog converters, filters, field programmable gate array+advanced RISC machine (FPGA+ARM) and other functional modules with the size of 160 mm×170 mm×42 mm, and a control algorithm is proposed based on digital phase-locked loop and proportional integral derivative (PID) controller. And thus the motion demodulation and feedback control of multi-sized particles are realized with this controller, as well as the sensing bandwidth of which is from tens of hertz to sub-megahertz. The experimental results demonstrate stable suspension and motion control of submicron-sized and micrometer-sized particles in ultra-high vacuum (10-6 Pa). With a higher sensing bandwidth and a smaller size, the integrated feedback controller offers a route for instrumented levitated optomechanical sensing technology.