The synchronous tracking control problem of a hydraulic parallel manipulator with six degrees of freedom (DOF) is complicated since the inclusion of hydraulic elements increases the order of the system.To solve this p...The synchronous tracking control problem of a hydraulic parallel manipulator with six degrees of freedom (DOF) is complicated since the inclusion of hydraulic elements increases the order of the system.To solve this problem,cascade control method with an inner/outer-loop control structure is used,which masks the hydraulic dynamics with the inner-loop so that the designed controller takes into account of both the mechanical dynamics and the hydraulic dynamics of the manipulator.Furthermore,a cross-coupling control approach is introduced to the synchronous tracking control of the manipulator.The position synchronization error is developed by considering motion synchronization between each actuator joint and its adjacent ones based on the synchronous goal.Then,with the feedback of both position error and synchronization error,the tracking is proven to guarantee that both the position errors and synchronization errors asymptotically converge to zero.Moreover,the effectiveness of the proposed approach is verified by the experimental results performed with a 6-DOF hydraulic parallel manipulator.展开更多
针对双馈风机经串补并网引发的次同步控制相互作用(sub-synchronous control interaction,SSCI)问题,提出一种有源电力滤波器(active power filter,APF)谐波补偿控制策略。基于双馈风机(doubly fed induction generator,DFIG)和串补输...针对双馈风机经串补并网引发的次同步控制相互作用(sub-synchronous control interaction,SSCI)问题,提出一种有源电力滤波器(active power filter,APF)谐波补偿控制策略。基于双馈风机(doubly fed induction generator,DFIG)和串补输电线路的等效阻抗电路,利用阻抗法分析了系统发生SSCI的原因和特性;设计有源电力滤波器,通过向有源电力滤波器内部控制器注入包含无功电流和振荡电流在内的谐波参考电流来抑制风电场的次同步控制相互作用,该谐波电流参考值可通过并网采样电流减去其有功电流获得,有功电流则通过对APF直流侧电压采用一阶自抗扰控制(active disturbance rejection control,ADRC)获得;仿真验证了所提APF补偿控制策略在抑制SSCI方面的可行性。展开更多
基金Project(50375139) supported by the National Natural Science Foundation of ChinaProject(NCET-04-0545) supported by the New Century Excellent Talent Plan of the Ministry of Education of China
文摘The synchronous tracking control problem of a hydraulic parallel manipulator with six degrees of freedom (DOF) is complicated since the inclusion of hydraulic elements increases the order of the system.To solve this problem,cascade control method with an inner/outer-loop control structure is used,which masks the hydraulic dynamics with the inner-loop so that the designed controller takes into account of both the mechanical dynamics and the hydraulic dynamics of the manipulator.Furthermore,a cross-coupling control approach is introduced to the synchronous tracking control of the manipulator.The position synchronization error is developed by considering motion synchronization between each actuator joint and its adjacent ones based on the synchronous goal.Then,with the feedback of both position error and synchronization error,the tracking is proven to guarantee that both the position errors and synchronization errors asymptotically converge to zero.Moreover,the effectiveness of the proposed approach is verified by the experimental results performed with a 6-DOF hydraulic parallel manipulator.
