Existing literature has shown that the control force at the nose could cause dynamic instability for controlled projectiles. To lower the adverse impact on the dual-spin projectile with fixed canards under the premise...Existing literature has shown that the control force at the nose could cause dynamic instability for controlled projectiles. To lower the adverse impact on the dual-spin projectile with fixed canards under the premise of meeting guidance system requirements, the influence of control moment provided by a motor on the flight stability is analyzed in this paper. Firstly, the effect of the rolling movement on stability is analyzed based on the stability criterion derived using the Hurwitz stability theory. Secondly, the evaluation parameters combining the features of different control periods that could assess the variation of stability features after the motor torque are obtained. These effective formulas are used to indicate that, to reduce the flight instability risks, the stabilized rolling speed of roll speed keeping period should be as small as possible; the variation trend of motor torque during the rolling speed controlling period and the roll angle of the forward body during roll angle switching period are recommended corresponding to the projectile and trajectory characteristics. Moreover,detailed numerical simulations of 155 mm dual-spin projectile are satisfactory agreement with the theoretical results.展开更多
双有源桥(dual active bridge,DAB)DC-DC变换器在其控制的灵活性与分析的简便性之间存在不可规避的矛盾,即控制自由度越高,分析越复杂。针对这一问题,该文提出从基础电路解析的角度对DAB的工作模式进行重塑,从而在提高其控制自由度的同...双有源桥(dual active bridge,DAB)DC-DC变换器在其控制的灵活性与分析的简便性之间存在不可规避的矛盾,即控制自由度越高,分析越复杂。针对这一问题,该文提出从基础电路解析的角度对DAB的工作模式进行重塑,从而在提高其控制自由度的同时降低分析的难度。首先,根据实际开关电路的特点,对单移相控制(single phase shift,SPS)下DAB的所有工作模态进行分析与重新定义,并基于模态分析对回流功率产生的电路本质进行解释。其次,详细阐述从模态角度抑制回流功率的分析方法。所采用的方法简化了DAB工作过程与功率传输特性的分析,对降低工程分析与设计难度具有较好的价值。最后仿真与实验验证分析方法的正确性。展开更多
文摘Existing literature has shown that the control force at the nose could cause dynamic instability for controlled projectiles. To lower the adverse impact on the dual-spin projectile with fixed canards under the premise of meeting guidance system requirements, the influence of control moment provided by a motor on the flight stability is analyzed in this paper. Firstly, the effect of the rolling movement on stability is analyzed based on the stability criterion derived using the Hurwitz stability theory. Secondly, the evaluation parameters combining the features of different control periods that could assess the variation of stability features after the motor torque are obtained. These effective formulas are used to indicate that, to reduce the flight instability risks, the stabilized rolling speed of roll speed keeping period should be as small as possible; the variation trend of motor torque during the rolling speed controlling period and the roll angle of the forward body during roll angle switching period are recommended corresponding to the projectile and trajectory characteristics. Moreover,detailed numerical simulations of 155 mm dual-spin projectile are satisfactory agreement with the theoretical results.
文摘双有源桥(dual active bridge,DAB)DC-DC变换器在其控制的灵活性与分析的简便性之间存在不可规避的矛盾,即控制自由度越高,分析越复杂。针对这一问题,该文提出从基础电路解析的角度对DAB的工作模式进行重塑,从而在提高其控制自由度的同时降低分析的难度。首先,根据实际开关电路的特点,对单移相控制(single phase shift,SPS)下DAB的所有工作模态进行分析与重新定义,并基于模态分析对回流功率产生的电路本质进行解释。其次,详细阐述从模态角度抑制回流功率的分析方法。所采用的方法简化了DAB工作过程与功率传输特性的分析,对降低工程分析与设计难度具有较好的价值。最后仿真与实验验证分析方法的正确性。
