针对欠驱动旋转激励平移振荡器(translational oscillations with a rotational actuator, TORA)系统的控制问题,使用一种自耦PID (self-coupling proportional-integral-differential, SCPID)控制方法.该方法首先利用坐标变换使TORA系...针对欠驱动旋转激励平移振荡器(translational oscillations with a rotational actuator, TORA)系统的控制问题,使用一种自耦PID (self-coupling proportional-integral-differential, SCPID)控制方法.该方法首先利用坐标变换使TORA系统的质心映射为Huygens振动中心,以实现新系统控制输入解耦,避免零动态不稳定问题;然后对Huygens振动中心设计平移位置的SCPID控制器,同时获得小球偏转角度的虚拟指令,进而设计小球偏转角度的SCPID控制器,从而实现TORA系统的平衡点跟踪控制;最后在复频域对闭环控制系统的稳定性进行严格的数学分析和证明.仿真及与其他方法的结果对比表明,所设计的控制算法简单高效,在欠驱动控制系统领域具有实际的应用价值.展开更多
针对由单电机驱动的欠驱动TORA(Translational oscillators with rotating actuator)系统,基于拉格朗日方程,建立其动力学模型。采用双闭环的模糊控制方案实现该系统的稳定控制,内环控制小球的摆角,外环控制小车的位置,设计了可靠的模...针对由单电机驱动的欠驱动TORA(Translational oscillators with rotating actuator)系统,基于拉格朗日方程,建立其动力学模型。采用双闭环的模糊控制方案实现该系统的稳定控制,内环控制小球的摆角,外环控制小车的位置,设计了可靠的模糊控制规则,仿真结果验证了控制器的有效性。展开更多
针对欠驱动水平TORA(translational oscillators with rotating actuator)系统,提出一种基于生物启发模型的有界输入控制方法,实现系统在执行器存在饱和约束情况下的镇定控制.首先,根据水平TORA系统的动力学模型分析系统的无源特性,进...针对欠驱动水平TORA(translational oscillators with rotating actuator)系统,提出一种基于生物启发模型的有界输入控制方法,实现系统在执行器存在饱和约束情况下的镇定控制.首先,根据水平TORA系统的动力学模型分析系统的无源特性,进而给出系统的控制目标;接着,基于无源特性构造一种新颖的Lyapunov函数,在此基础上设计一种结构简单的非线性状态反馈控制器;然后,考虑执行器的饱和约束条件,引入受生物启发建立的神经动力学模型,利用该模型的有界平滑输出特性,设计一种改进的状态反馈控制器;最后,根据LaSalle不变性原理对系统的稳定性进行严格的数学分析和证明.与其他方法相比,所提方法不仅考虑了执行器的饱和约束问题,而且设计的控制算法简单高效,易于工程实现.仿真与对比结果表明,所提方法具有更好的控制性能.展开更多
针对欠驱动TORA(Translational oscillations with a rotational actuator)系统,设计了一种具有执行器饱和约束的输出反馈等[7]特别地,由Rand学者提出的TORA系统,最初控制器.与其他现有方法相比,本文方法不仅考虑了执行器饱和约束和作...针对欠驱动TORA(Translational oscillations with a rotational actuator)系统,设计了一种具有执行器饱和约束的输出反馈等[7]特别地,由Rand学者提出的TORA系统,最初控制器.与其他现有方法相比,本文方法不仅考虑了执行器饱和约束和作为双自旋航天器的简化模型用于研究自振现象.后来由于速度信号不可测情形,而且考虑了旋转小球可能存在的循环行为.具体而TORA系统具有强耦合、高度非线性、欠驱动等特性,而被言,首先根据TORA系统模型分析了TORA系统的控制目标;随后,作为一种非线性基准系统主要用于非线性控制器设计、验证构造了一种新颖的能量函数,在此基础上设计了一种考虑执行器饱和约非线性控制算法的控制性能或教学研究.目前国内外已有多束的输出反馈控制器,并通过严格的数学分析证明了闭环系统关于平衡点的稳定性;最后,借助数值仿真测试检验了所提控制器的控制性能,并所高校和研究机构针对TORA系统的控制问题展开研究.对与已有方法进行了对比.仿真测试结果表明本文所提方法具有更好的控法制性能.展开更多
The repetitive control(RC) or repetitive controller problem for nonminimum phase nonlinear systems is both challenging and practical. In this paper, we consider an RC problem for the translational oscillator with a ro...The repetitive control(RC) or repetitive controller problem for nonminimum phase nonlinear systems is both challenging and practical. In this paper, we consider an RC problem for the translational oscillator with a rotational actuator(TORA), which is a nonminimum phase nonlinear system. The major difficulty is to handle both a nonminimum phase RC problem and a nonlinear problem simultaneously. For such purpose, a new RC design, namely the additive-state-decomposition-based approach, is proposed,by which the nonminimum phase RC problem and the nonlinear problem are separated. This makes RC for the TORA benchmark tractable. To demonstrate the effectiveness of the proposed approach, a numerical simulation is given.展开更多
Objetive: To explore the potential insecticidal, ovipositor deterrent and antifeedant effects of ethyl acetate extract of the seeds of Senna tora(Syn. Cassia tora) against cowpea weevil(Callosobruchus maculatus).Metho...Objetive: To explore the potential insecticidal, ovipositor deterrent and antifeedant effects of ethyl acetate extract of the seeds of Senna tora(Syn. Cassia tora) against cowpea weevil(Callosobruchus maculatus).Method: The activities were evaluated using standard protocols.In these bioassays, the cowpea seeds were used directly as an insect feed. The activity of the extract and isolated compounds were tested at concentrations of 100, 200 and 300 μg/mL and compared to neem oil and cinnamaldehyde(as standard positive controls). Phytochemical analysis of the ethyl acetate extract was done through a number of chromatographic techniques and the structures of the isolated compounds were established through comprehensive spectroscopic analysis including 2 D-NMR and ESI-MS studies.Results: Fractionation of the active ethyl acetate extract resulted in the isolation of one known anthraquinone,aurantio-obtusin(1) and a novel compound that was named as cassiatorin(2). Compounds1 and 2 showed comparable insect antifeedant properties with the positive controls while their insecticidal and ovipositor deterrent effects were far superior to the standard controls.Conclusions: It is thus concluded that Senna tora extracts and the isolated compounds(1 and2) may be employed in the postharvest management of stored cowpea seeds and as other crop protectants.展开更多
文摘针对欠驱动旋转激励平移振荡器(translational oscillations with a rotational actuator, TORA)系统的控制问题,使用一种自耦PID (self-coupling proportional-integral-differential, SCPID)控制方法.该方法首先利用坐标变换使TORA系统的质心映射为Huygens振动中心,以实现新系统控制输入解耦,避免零动态不稳定问题;然后对Huygens振动中心设计平移位置的SCPID控制器,同时获得小球偏转角度的虚拟指令,进而设计小球偏转角度的SCPID控制器,从而实现TORA系统的平衡点跟踪控制;最后在复频域对闭环控制系统的稳定性进行严格的数学分析和证明.仿真及与其他方法的结果对比表明,所设计的控制算法简单高效,在欠驱动控制系统领域具有实际的应用价值.
文摘针对由单电机驱动的欠驱动TORA(Translational oscillators with rotating actuator)系统,基于拉格朗日方程,建立其动力学模型。采用双闭环的模糊控制方案实现该系统的稳定控制,内环控制小球的摆角,外环控制小车的位置,设计了可靠的模糊控制规则,仿真结果验证了控制器的有效性。
文摘针对欠驱动水平TORA(translational oscillators with rotating actuator)系统,提出一种基于生物启发模型的有界输入控制方法,实现系统在执行器存在饱和约束情况下的镇定控制.首先,根据水平TORA系统的动力学模型分析系统的无源特性,进而给出系统的控制目标;接着,基于无源特性构造一种新颖的Lyapunov函数,在此基础上设计一种结构简单的非线性状态反馈控制器;然后,考虑执行器的饱和约束条件,引入受生物启发建立的神经动力学模型,利用该模型的有界平滑输出特性,设计一种改进的状态反馈控制器;最后,根据LaSalle不变性原理对系统的稳定性进行严格的数学分析和证明.与其他方法相比,所提方法不仅考虑了执行器的饱和约束问题,而且设计的控制算法简单高效,易于工程实现.仿真与对比结果表明,所提方法具有更好的控制性能.
文摘针对欠驱动TORA(Translational oscillations with a rotational actuator)系统,设计了一种具有执行器饱和约束的输出反馈等[7]特别地,由Rand学者提出的TORA系统,最初控制器.与其他现有方法相比,本文方法不仅考虑了执行器饱和约束和作为双自旋航天器的简化模型用于研究自振现象.后来由于速度信号不可测情形,而且考虑了旋转小球可能存在的循环行为.具体而TORA系统具有强耦合、高度非线性、欠驱动等特性,而被言,首先根据TORA系统模型分析了TORA系统的控制目标;随后,作为一种非线性基准系统主要用于非线性控制器设计、验证构造了一种新颖的能量函数,在此基础上设计了一种考虑执行器饱和约非线性控制算法的控制性能或教学研究.目前国内外已有多束的输出反馈控制器,并通过严格的数学分析证明了闭环系统关于平衡点的稳定性;最后,借助数值仿真测试检验了所提控制器的控制性能,并所高校和研究机构针对TORA系统的控制问题展开研究.对与已有方法进行了对比.仿真测试结果表明本文所提方法具有更好的控法制性能.
基金supported by National Natural Science Foundation of China(No.61473012)
文摘The repetitive control(RC) or repetitive controller problem for nonminimum phase nonlinear systems is both challenging and practical. In this paper, we consider an RC problem for the translational oscillator with a rotational actuator(TORA), which is a nonminimum phase nonlinear system. The major difficulty is to handle both a nonminimum phase RC problem and a nonlinear problem simultaneously. For such purpose, a new RC design, namely the additive-state-decomposition-based approach, is proposed,by which the nonminimum phase RC problem and the nonlinear problem are separated. This makes RC for the TORA benchmark tractable. To demonstrate the effectiveness of the proposed approach, a numerical simulation is given.
基金The financial assistance from the Swedish International Development Agency for some of the study (travel grant for Valantine Mbatchou)
文摘Objetive: To explore the potential insecticidal, ovipositor deterrent and antifeedant effects of ethyl acetate extract of the seeds of Senna tora(Syn. Cassia tora) against cowpea weevil(Callosobruchus maculatus).Method: The activities were evaluated using standard protocols.In these bioassays, the cowpea seeds were used directly as an insect feed. The activity of the extract and isolated compounds were tested at concentrations of 100, 200 and 300 μg/mL and compared to neem oil and cinnamaldehyde(as standard positive controls). Phytochemical analysis of the ethyl acetate extract was done through a number of chromatographic techniques and the structures of the isolated compounds were established through comprehensive spectroscopic analysis including 2 D-NMR and ESI-MS studies.Results: Fractionation of the active ethyl acetate extract resulted in the isolation of one known anthraquinone,aurantio-obtusin(1) and a novel compound that was named as cassiatorin(2). Compounds1 and 2 showed comparable insect antifeedant properties with the positive controls while their insecticidal and ovipositor deterrent effects were far superior to the standard controls.Conclusions: It is thus concluded that Senna tora extracts and the isolated compounds(1 and2) may be employed in the postharvest management of stored cowpea seeds and as other crop protectants.
