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
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
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
针对TORA(Translational oscillator with rotating actuator)系统的镇定控制问题,提出一种基于θ-D方法的非线性最优控制方案.应用拉格朗日方程建立TORA系统的数学模型,为保证状态空间形式的TORA系统数学模型中状态向量系数矩阵A(x)能...针对TORA(Translational oscillator with rotating actuator)系统的镇定控制问题,提出一种基于θ-D方法的非线性最优控制方案.应用拉格朗日方程建立TORA系统的数学模型,为保证状态空间形式的TORA系统数学模型中状态向量系数矩阵A(x)能够分离出常值矩阵,且其能与控制位置矩阵构成可控对,采用不同于传统形式的解耦坐标变换对TORA系统进行了处理,以此为基础为TORA系统设计基于θ-D方法的非线性最优控制器,该控制方案可离线得到控制输入的显示表达式.通过数值仿真以及与基于局部线性化的线性最优控制方案进行比较,验证了所提非线性最优控制方案所具有的良好瞬态性能.展开更多
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。
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.
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.
文摘针对TORA(Translational oscillator with rotating actuator)系统的镇定控制问题,提出一种基于θ-D方法的非线性最优控制方案.应用拉格朗日方程建立TORA系统的数学模型,为保证状态空间形式的TORA系统数学模型中状态向量系数矩阵A(x)能够分离出常值矩阵,且其能与控制位置矩阵构成可控对,采用不同于传统形式的解耦坐标变换对TORA系统进行了处理,以此为基础为TORA系统设计基于θ-D方法的非线性最优控制器,该控制方案可离线得到控制输入的显示表达式.通过数值仿真以及与基于局部线性化的线性最优控制方案进行比较,验证了所提非线性最优控制方案所具有的良好瞬态性能.
