Membrane structures are attracting attention as excellent candidates for lightweight large space structures, which can be utilized to improve the performance and reduce the cost of space exploration and earth observation missions. Membrane structures can be stowed to a small volume during launch and function as large structures after deployed. For many applications, maintaining surface accuracy of membranes is extremely important to achieve satisfactory performance, especially for membrane antennas and adaptive optics. Active flatness control is a vital technology to maintain surface accuracy of membrane structures. In this research, multiple shape memory alloy (SMA) actuators around the boundary of a rectangular membrane are used to apply tension forces to membrane structures to compensate wrinkle effects. The dynamics of membrane structures is nonlinear and computationally expensive, hence unfeasible to be used in real-time active flatness control. As a parallel direct searching method, genetic algorithm (GA) is used search optimal tension force combination on a high dimensional nonlinear surface. Due to increasing number of tension forces to search, the convergence is more difficult to attain. In order to increase responsiveness and convergence of genetic algorithm, an adaptive genetic algorithm (AGA) is proposed. Adaptive rules are incorporated in a modified genetic algorithm to regulate control parameters of genetic algorithm. Through numerical simulation and experimental studies, it is demonstrated that AGA can expedite its search process and prevent premature convergence.
[1]
Jonathan T. Black,et al.
STRUCTURAL ANALYSIS AND TESTING OF A SUBSCALE SUNSHIELD MEMBRANE LAYER
,
2003
.
[2]
Canadian Space Agency,et al.
Tests of Inflatable Structure Shape Control Using Genetic Algorithm and Neural Network
,
2005
.
[3]
Alexander Tessler,et al.
Nonlinear Shell Modeling of Thin Membranes with Emphasis on Structural Wrinkling
,
2003
.
[4]
S. Pellegrino,et al.
WRINKLED MEMBRANES PART II: ANALYTICAL MODELS
,
2006
.
[5]
Christopher H. M. Jenkins,et al.
Gossamer spacecraft : membrane and inflatable structures technology for space applications
,
2001
.
[6]
Emanuele Trucco,et al.
Introductory techniques for 3-D computer vision
,
1998
.
[7]
Yahya Rahmat-Samii,et al.
Advanced precipitation radar antenna
,
2003
.
[8]
Edward E Montgomery,et al.
THE DEVELOPMENT OF SOLAR SAIL PROPULSION FOR NASA SCIENCE MISSIONS TO THE INNER SOLAR SYSTEM
,
2004
.
[9]
Mitsuo Gen,et al.
Genetic algorithms and engineering design
,
1997
.
[10]
R. K. Miller,et al.
An algorithm for finite element analysis of partly wrinkled membranes
,
1982
.