ResponseAnalysisofDeceleration Motion Control for Pipeline Intelligent Plugging Robot
Wang Shanshan1Jiang Zhengguo² (1.ResearchstituteofureyDsignamp;IformationTechnologyPetroCinaJidongOifeldCompany;.holofical Engineering,SouthwestPetroleumUniversity)
Abstract: Pipeline intelligent plugging robot (PIPR) is an indispensable high-end equipmentfor rapid maintenance and emergency repair operation of pipeline within 12 hours.Achieving eficient and stable deceleration is crucialto the success of plugging operation.A hydraulic controlsystem was designed foraPIPR that uses friction between the slip and the pipe wall to achieve deceleration and positioning.Then,a nonlinear dynamic model of constant deceleration was built for the servo PIPR based on fuzzy PID control.Finall,the numerical simulation method was used to conduct a mechanical-hydraulic co-simulation of the hydraulic control system,and study the influence of important parametersof the control systemon the dynamic control stabilityof the PIPR during the deceleration process.The studyresultsshow that as the initial velocity increases,the centroid accelerationof the PIPR gradually increases,with a maximum overshoot of -3.4m/s2 ,deceleration process control time within 30 seconds,and positioning accuracy within 5% .Increasing the expected deceleration distance can effectively reduce positioning eror;thecapacityoftheaccumulatorshouldbe atleast greater than O.25L.The numberof accumula torshas a relatively small impact on the system.
Keywords:PIPR;dynamic response;fuzzy PID;deceleration control
0 引言
管道是石油、天然气最主要的运输方式,全球陆上 70% 的石油和 99% 的天然气依靠管道运输[]。经过长期运营后管道会因腐蚀、地质运动、管材和施工质量等原因产生缺陷,这就需要及时对缺陷位置进行准确抢修,以避免油气泄漏甚至爆炸等重大事故的发生[2]。相较于传统带压封堵技术,管内封堵技术的优势在于不需要对管壁进行开孔操作,减少了挖掘、开孔及焊接等工作,减少了工程量,同时也避免了对管道的反复伤害,提高了封堵作业的安全性和可靠性[3-4]。目前管道智能封堵机器人(Pipeline IntelligentPluggingRobot,PIPR)产品减速定位多采用前置可控节流调速清管器实现。例如,TDW公司,SmartPlug、STATSGroup公司,TecnoPlug等[5]。但通常管内液体受阀门冲击、外界干扰以及管道内壁焊缝杂质等影响,流量会存在较大波动,这使得依靠该种节流调速方式的机器人减速距离控制不够理想,甚至导致其无法在指定位置封堵[6]。
流体驱动式PIPR的速度变化与管道内流体紧密相关,在减速过程中,其质心加速度的准确及稳定性决定了PIPR减速定位精度,该过程是一个典型的电液力伺服控制。PIPR减速时会影响到管内流场载荷分布,同时PIPR前后端流场的扰动又将引起压力载荷突变,致使机器人速度呈现非线性,进一步加剧流场变化;通过调节液压系统实时控制卡瓦与管壁间的摩擦力大小,跟踪非线性变化,使得机器人按照一个恒定的加速度进行减速,可在预期位置完成减速锚定。在机器人作业过程中,减速定位精度不仅影响机器人后续封堵、更换损伤管道的抢修效率,而且误差会增加机器人微调以及二次作业等附加工作,这对依靠自身内部能源动作的机器人极其不利。……