四旋翼飞行器系统是强耦合、多输入多输出(MIMO)和非线性的。首先进行动力学建模,考虑模型参数确定与阵风干扰两种情况;然后提出了一种自适应积分反步控制方法应用于飞行器跟踪期望轨迹,整个控制系统采用双闭环回路结构,内回路用于控制...四旋翼飞行器系统是强耦合、多输入多输出(MIMO)和非线性的。首先进行动力学建模,考虑模型参数确定与阵风干扰两种情况;然后提出了一种自适应积分反步控制方法应用于飞行器跟踪期望轨迹,整个控制系统采用双闭环回路结构,内回路用于控制姿态,外回路用于稳定位置;最后在模型参数确定的情况下,与积分反步法(integral backstepping,IB)进行实验对比。在模型参数不确定情况下,对飞行器的期望姿态和位移进行跟踪,结果表明,应用自适应积分反步(adaptive integral backstepping,AIB)控制算法的飞行器对外界较强阵风干扰和模型参数不确定具有一定的鲁棒性,能够较为精确地完成轨迹跟踪任务。展开更多
The influence of frequency modulation （FM） interfer- ence on correlation detection performance of the pseudo random code continuous wave （PRC-CW） radar is analyzed. It is found that the correlation output deterior...The influence of frequency modulation （FM） interfer- ence on correlation detection performance of the pseudo random code continuous wave （PRC-CW） radar is analyzed. It is found that the correlation output deteriorates greatly when the FM inter- ference power exceeds the anti-jamming limit of the radar. Accord- ing to the fact that the PRC-CW radar echo is a wideband pseudo random signal occupying the whole TF plane, while the FM in- terference only concentrates in a small portion, a new method is proposed based on adaptive short-time Fourier transform （STFT） and time-varying filtering for FM interference suppression. This method filters the received signal by using a binary mask to excise only the portion of the TF plane corrupted by the interference. Two types of interference, linear FM （LFM） and sinusoidal FM （SFM）, under different signal-to-jamming ratio （S JR） are studied. It is shown that the proposed method can effectively suppress the FM interference and improve the performance of target detection.展开更多
文摘四旋翼飞行器系统是强耦合、多输入多输出(MIMO)和非线性的。首先进行动力学建模,考虑模型参数确定与阵风干扰两种情况;然后提出了一种自适应积分反步控制方法应用于飞行器跟踪期望轨迹,整个控制系统采用双闭环回路结构,内回路用于控制姿态,外回路用于稳定位置;最后在模型参数确定的情况下,与积分反步法(integral backstepping,IB)进行实验对比。在模型参数不确定情况下,对飞行器的期望姿态和位移进行跟踪,结果表明,应用自适应积分反步(adaptive integral backstepping,AIB)控制算法的飞行器对外界较强阵风干扰和模型参数不确定具有一定的鲁棒性,能够较为精确地完成轨迹跟踪任务。
文摘The influence of frequency modulation （FM） interfer- ence on correlation detection performance of the pseudo random code continuous wave （PRC-CW） radar is analyzed. It is found that the correlation output deteriorates greatly when the FM inter- ference power exceeds the anti-jamming limit of the radar. Accord- ing to the fact that the PRC-CW radar echo is a wideband pseudo random signal occupying the whole TF plane, while the FM in- terference only concentrates in a small portion, a new method is proposed based on adaptive short-time Fourier transform （STFT） and time-varying filtering for FM interference suppression. This method filters the received signal by using a binary mask to excise only the portion of the TF plane corrupted by the interference. Two types of interference, linear FM （LFM） and sinusoidal FM （SFM）, under different signal-to-jamming ratio （S JR） are studied. It is shown that the proposed method can effectively suppress the FM interference and improve the performance of target detection.
