In this paper,the collective motion of self-driven robots is studied experimentally and theoretically.In the channel,the flowrate of robots increases with the density linearly,even if the density of the robots tends t...In this paper,the collective motion of self-driven robots is studied experimentally and theoretically.In the channel,the flowrate of robots increases with the density linearly,even if the density of the robots tends to 1.0.There is no abrupt drop in the flowrate,similar to the collective motion of ants.We find that the robots will adjust their velocities by a serial of tiny collisions.The speed-adjustment will affect both robots involved in the collision,and will help to maintain a nearly uniform velocity for the robots.As a result,the flowrate drop will disappear.In the motion,the robots neither gather together nor scatter completely.Instead,they form some clusters to move together.These clusters are not stable during the moving process,but their sizes follow a power-law-alike distribution.We propose a theoretical model to simulate this collective motion process,which can reproduce these behaviors well.Analytic results about the flowrate behavior are also consistent with experiments.展开更多
基于超声波时差测量流量的方法具有非接触、易安装、不改变流体的运动状态等优点,被广泛应用于油田井下流体流速测量分析领域,能够实时测量流体流速,准确分析管道中流体流量的变化。针对传统的超声波流量计功耗高、电路复杂的缺点,根据...基于超声波时差测量流量的方法具有非接触、易安装、不改变流体的运动状态等优点,被广泛应用于油田井下流体流速测量分析领域,能够实时测量流体流速,准确分析管道中流体流量的变化。针对传统的超声波流量计功耗高、电路复杂的缺点,根据超声波时差法测量流量的原理,结合井下高温测量环境,以及未来测井仪器低功耗、小型化的需求,以dsPIC33EV为主控芯片,设计了一种低功耗、小型化的井下超声波流量测量系统。该系统利用dsPIC33EV的充电时间测量单元CTMU(Charging Time Measurement Unit),实现声波传播时差与流量的高精度测量与计算。室内实验平台测试数据表明,该文设计的井下超声波流量测量系统测量相对误差为±7.2%,典型功耗为20mW,技术指标满足生产井流量监测需求。展开更多
基金Project supported by the Key Research and Development Program,China(Grant No.2016YFC0802508)the National Natural Science Foundation of China(Grant Nos.11672289 and 11422221)
文摘In this paper,the collective motion of self-driven robots is studied experimentally and theoretically.In the channel,the flowrate of robots increases with the density linearly,even if the density of the robots tends to 1.0.There is no abrupt drop in the flowrate,similar to the collective motion of ants.We find that the robots will adjust their velocities by a serial of tiny collisions.The speed-adjustment will affect both robots involved in the collision,and will help to maintain a nearly uniform velocity for the robots.As a result,the flowrate drop will disappear.In the motion,the robots neither gather together nor scatter completely.Instead,they form some clusters to move together.These clusters are not stable during the moving process,but their sizes follow a power-law-alike distribution.We propose a theoretical model to simulate this collective motion process,which can reproduce these behaviors well.Analytic results about the flowrate behavior are also consistent with experiments.
文摘基于超声波时差测量流量的方法具有非接触、易安装、不改变流体的运动状态等优点,被广泛应用于油田井下流体流速测量分析领域,能够实时测量流体流速,准确分析管道中流体流量的变化。针对传统的超声波流量计功耗高、电路复杂的缺点,根据超声波时差法测量流量的原理,结合井下高温测量环境,以及未来测井仪器低功耗、小型化的需求,以dsPIC33EV为主控芯片,设计了一种低功耗、小型化的井下超声波流量测量系统。该系统利用dsPIC33EV的充电时间测量单元CTMU(Charging Time Measurement Unit),实现声波传播时差与流量的高精度测量与计算。室内实验平台测试数据表明,该文设计的井下超声波流量测量系统测量相对误差为±7.2%,典型功耗为20mW,技术指标满足生产井流量监测需求。
