This paper investigates interception missiles’trajectory tracking guidance problem under wind field and external disturbances in the boost phase.Indeed,the velocity control in such trajectory tracking guidance system...This paper investigates interception missiles’trajectory tracking guidance problem under wind field and external disturbances in the boost phase.Indeed,the velocity control in such trajectory tracking guidance systems of missiles is challenging.As our contribution,the velocity control channel is designed to deal with the intractable velocity problem and improve tracking accuracy.The global prescribed performance function,which guarantees the tracking error within the set range and the global convergence of the tracking guidance system,is first proposed based on the traditional PPF.Then,a tracking guidance strategy is derived using the integral sliding mode control techniques to make the sliding manifold and tracking errors converge to zero and avoid singularities.Meanwhile,an improved switching control law is introduced into the designed tracking guidance algorithm to deal with the chattering problem.A back propagation neural network(BPNN)extended state observer(BPNNESO)is employed in the inner loop to identify disturbances.The obtained results indicate that the proposed tracking guidance approach achieves the trajectory tracking guidance objective without and with disturbances and outperforms the existing tracking guidance schemes with the lowest tracking errors,convergence times,and overshoots.展开更多
研究空间结构中悬臂梁的主动振动控制。首先使用PPF(Positive Position Feedback)的主动振动控制方法,得到和一般负反馈相比相对优化的脉冲响应,再利用结构频率与特征方程根的关系进行最优化参数选取,最后进行仿真。仿真结果表明基于PP...研究空间结构中悬臂梁的主动振动控制。首先使用PPF(Positive Position Feedback)的主动振动控制方法,得到和一般负反馈相比相对优化的脉冲响应,再利用结构频率与特征方程根的关系进行最优化参数选取,最后进行仿真。仿真结果表明基于PPF方法主动振动控制能够很好地实现对悬臂梁结构的振动控制。展开更多
研究利用PPF(Positive Position Feedback)和PD(Proportional-Derivative)相结合的方法对悬臂梁进行主动振动控制。理论分析表明:采用PPF和PD相结合对梁进行振动控制优于单独使用PPF对悬臂梁的振动控制;利用根轨迹以及作动器结构频率和...研究利用PPF(Positive Position Feedback)和PD(Proportional-Derivative)相结合的方法对悬臂梁进行主动振动控制。理论分析表明:采用PPF和PD相结合对梁进行振动控制优于单独使用PPF对悬臂梁的振动控制;利用根轨迹以及作动器结构频率和系统特征根实部的关系对该方法的相关参数进行优化;比对悬臂进行主动振动控制仿真,结果表明:该方法的控制效果要比PPF方法的效果好,且参数优化过后,控制效果得到进一步改善。展开更多
针对机器人无序工件分拣过程中在遮挡情况下不同外形工件识别率差异较大的问题,对全局特征描述子和局部特征描述子的描述及投票过程进行详细地分析,分别选取其中实时性较好的PPF(Point Pair Feature)和SHOT(Signature of Histograms of ...针对机器人无序工件分拣过程中在遮挡情况下不同外形工件识别率差异较大的问题,对全局特征描述子和局部特征描述子的描述及投票过程进行详细地分析,分别选取其中实时性较好的PPF(Point Pair Feature)和SHOT(Signature of Histograms of OrienTations)描述子在不同程度遮挡情况下使用不同外形工件进行识别实验,有针对性地对机器人无序分拣中不同外形工件适用的算法进行实验对比和总结,使在不同外形工件上的识别率达到最大化,实验结果表明:PPF全局描述子对工件点云模型的外形特征和遮挡较为敏感,特征不明显工件的识别率为0%,对于外形特征明显、无遮挡的点云模型工件识别速度较快(1 s内)且准确率较高,SHOT局部描述子对遮挡的鲁棒性较强,并且对外形特征不明显工件有一定的识别能力,特征明显与特征不明显工件的识别率均保持在90%以上。展开更多
基金the National Natural Science Foundation of China(Grant No.12072090).
文摘This paper investigates interception missiles’trajectory tracking guidance problem under wind field and external disturbances in the boost phase.Indeed,the velocity control in such trajectory tracking guidance systems of missiles is challenging.As our contribution,the velocity control channel is designed to deal with the intractable velocity problem and improve tracking accuracy.The global prescribed performance function,which guarantees the tracking error within the set range and the global convergence of the tracking guidance system,is first proposed based on the traditional PPF.Then,a tracking guidance strategy is derived using the integral sliding mode control techniques to make the sliding manifold and tracking errors converge to zero and avoid singularities.Meanwhile,an improved switching control law is introduced into the designed tracking guidance algorithm to deal with the chattering problem.A back propagation neural network(BPNN)extended state observer(BPNNESO)is employed in the inner loop to identify disturbances.The obtained results indicate that the proposed tracking guidance approach achieves the trajectory tracking guidance objective without and with disturbances and outperforms the existing tracking guidance schemes with the lowest tracking errors,convergence times,and overshoots.
文摘研究空间结构中悬臂梁的主动振动控制。首先使用PPF(Positive Position Feedback)的主动振动控制方法,得到和一般负反馈相比相对优化的脉冲响应,再利用结构频率与特征方程根的关系进行最优化参数选取,最后进行仿真。仿真结果表明基于PPF方法主动振动控制能够很好地实现对悬臂梁结构的振动控制。
文摘研究利用PPF(Positive Position Feedback)和PD(Proportional-Derivative)相结合的方法对悬臂梁进行主动振动控制。理论分析表明:采用PPF和PD相结合对梁进行振动控制优于单独使用PPF对悬臂梁的振动控制;利用根轨迹以及作动器结构频率和系统特征根实部的关系对该方法的相关参数进行优化;比对悬臂进行主动振动控制仿真,结果表明:该方法的控制效果要比PPF方法的效果好,且参数优化过后,控制效果得到进一步改善。
文摘针对机器人无序工件分拣过程中在遮挡情况下不同外形工件识别率差异较大的问题,对全局特征描述子和局部特征描述子的描述及投票过程进行详细地分析,分别选取其中实时性较好的PPF(Point Pair Feature)和SHOT(Signature of Histograms of OrienTations)描述子在不同程度遮挡情况下使用不同外形工件进行识别实验,有针对性地对机器人无序分拣中不同外形工件适用的算法进行实验对比和总结,使在不同外形工件上的识别率达到最大化,实验结果表明:PPF全局描述子对工件点云模型的外形特征和遮挡较为敏感,特征不明显工件的识别率为0%,对于外形特征明显、无遮挡的点云模型工件识别速度较快(1 s内)且准确率较高,SHOT局部描述子对遮挡的鲁棒性较强,并且对外形特征不明显工件有一定的识别能力,特征明显与特征不明显工件的识别率均保持在90%以上。
