科技报告详细信息
Output Feedback Adaptive Control of Non-Minimum Phase Systems Using Optimal Control Modification
Nguyen, Nhan ; Hashemi, Kelley E ; Yucelen, Tansel ; Arabi, Ehsan
关键词: ADAPTIVE CONTROL;    FEEDBACK CONTROL;    OPTIMAL CONTROL;    SISO (CONTROL SYSTEMS);    MIMO (CONTROL SYSTEMS);    MODEL REFERENCE ADAPTIVE CONTROL;    APPROACH CONTROL;    CANCELLATION;    STABILITY;    FLEXIBLE WINGS;   
RP-ID  :  ARC-E-DAA-TN50749
美国|英语
来源: NASA Technical Reports Server
PDF
【 摘 要 】

This paper describes output feedback adaptive control approaches for non-minimum phase SISO systems with relative degree 1 and non-strictly positive real (SPR) MIMO systems with uniform relative degree 1 using the optimal control modification method. It is well-known that the standard model-reference adaptive control (MRAC) cannot be used to control non-SPR plants to track an ideal SPR reference model. Due to the ideal property of asymptotic tracking, MRAC attempts an unstable pole-zero cancellation which results in unbounded signals for non-minimum phase SISO systems. The optimal control modification can be used to prevent the unstable pole-zero cancellation which results in a stable adaptation of non-minimum phase SISO systems. However, the tracking performance using this approach could suffer if the unstable zero is located far away from the imaginary axis. The tracking performance can be recovered by using an observer-based output feedback adaptive control approach which uses a Luenberger observer design to estimate the state information of the plant. Instead of explicitly specifying an ideal SPR reference model, the reference model is established from the linear quadratic optimal control to account for the non-minimum phase behavior of the plant. With this non-minimum phase reference model, the observer-based output feedback adaptive control can maintain stability as well as tracking performance. However, in the presence of the mismatch between the SPR reference model and the non-minimum phase plant, the standard MRAC results in unbounded signals, whereas a stable adaptation can be achieved with the optimal control modification. An application of output feedback adaptive control for a flexible wing aircraft illustrates the approaches.

【 预 览 】
附件列表
Files Size Format View
20180001213.pdf 2234KB PDF download
  文献评价指标  
  下载次数:10次 浏览次数:17次