As a new class of smart materials, shape memory polymers and their composites (SMPs and SMPCs) can respond to specific external stimulus and remember the original shape. There are many types of stimulus methods to actuate the deformation of SMPs and SMPCs, of which the thermal- and electro-responsive components and structures are common. In this review, the general mechanism of SMPs and SMPCs are first introduced, the stimulus methods are then discussed to demonstrate the shape recovery effect, and finally, the applications of SMPs and SMPCs that are reinforced with fiber materials in aerospace are reviewed. SMPC hinges and booms are discussed in the part on components; the booms can be divided again into foldable SMPC truss booms, coilable SMPC truss booms and storable tubular extendible member (STEM) booms. In terms of SMPC structures, the solar array and deployable panel, reflector antenna and morphing wing are introduced in detail. Considering the factors of weight, recovery force and shock effect, SMPCs are expected to have great potential applications in aerospace.

https://iopscience.iop.org/article/10.1088/0964-1726/23/2/023001/pdf

Shape memory polymers and their composites in aerospace applications: a review

Adaptive control is now finding its way into the marketplace after many years of effort. This paper reviews some ideas used to design adaptive control systems. It covers early ideas which primarily attempt to compensate for gain variations and more general methods like gain scheduling, model reference adaptive control, and self-tuning regulators. It is shown that adaptive control laws can be obtained using stochastic control theory. Techniques for analyzing adaptive systems are discussed. This covers stability and convergence analysis. Issues of importance for applications like parameterization, tuning, and tracking, as well as different ways of using adaptive control are also discussed. An overview of applications which includes feasibility studies as well as products based on adaptive techniques concludes the paper.

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Adaptive feedback control

/pdf/adaptive-feedback-control-384lkskmt0.pdf

Adaptive Feedback Control

The demand for large antennas in future space missions has increasingly stimulated the development of deployable membrane antenna structures owing to their light weight and small stowage volume. However, there is little literature providing a comprehensive review and comparison of different membrane antenna structures. Space-borne membrane antenna structures are mainly classified as either parabolic or planar membrane antenna structures. For parabolic membrane antenna structures, there are five deploying and forming methods, including inflation, inflation-rigidization, elastic ribs driven, Shape Memory Polymer (SMP)-inflation, and electrostatic forming. The development and detailed comparison of these five methods are presented. Then, properties of membrane materials (including polyester film and polyimide film) for parabolic membrane antennas are compared. Additionally, for planar membrane antenna structures, frame shapes have changed from circular to rectangular, and different tensioning systems have emerged successively, including single Miura–Natori, double, and multi-layer tensioning systems. Recent advances in structural configurations, tensioning system design, and dynamic analysis for planar membrane antenna structures are investigated. Finally, future trends for large space membrane antenna structures are pointed out and technical problems are proposed, including design and analysis of membrane structures, materials and processes, membrane packing, surface accuracy stability, and test and verification technology. Through a review of large deployable membrane antenna structures, guidance for space membrane-antenna research and applications is provided.

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Review of Large Spacecraft Deployable Membrane Antenna Structures

https://link.springer.com/content/pdf/10.1007/s10338-019-00103-9.pdf

Mechanical Models, Structures, and Applications of Shape-Memory Polymers and Their Composites

A novel mission concept, namely NEXRAD in Space, has been developed for detailed monitoring of hurricanes, cyclones, and severe storms from a geostationary orbit. This mission concept requires a space deployable 35-m diameter reflector that operates at 35GHz with a surface figure accuracy requirement of 0.21 mm RMS. This reflector is well beyond the current state-of-the-art. To implement this mission concept, several potential technologies associated with large, lightweight, spaceborne reflectors have been investigated by this study. These spaceborne reflector technologies include mesh reflector technology, inflatable membrane reflector technology and Shape Memory Polymer reflector technology.

http://www.northropgrumman.com/BusinessVentures/AstroAerospace/Documents/pageDocs/tech_papers/tech_papers_AIAATech.pdf

Prospects of Large Deployable Reflector Antennas for a New Generation of Geostationary Doppler Weather Radar Satellites

A Steering Control System to Minimize Propulsion Losses of High-Speed Containerships—Part I: System Dynamics

A Large and High Radio Frequency Deployable Reflector

A Steering Control System to Minimize Propulsion Losses of High-Speed Containerships—Part II: Controller Design

A system to control a hydraulic industrial arm using a 4-bit microcomputer is described. A supervisory minicomputer can handle global routines such as scene analysis and task and trajectory planing while the microcomputer attends to the control of the arm. The microcomputer monitors arm joint positions and sensors, and maintains current joint position when no motion is desired. The supervisory minicomputer transfers a job to the microcomputer in the form of a sequence of macro-commands. The microcomputer interprets and executes the job and returns the final status of the arm to the minicoputer.

J. W. Moore

Papers

Prospects of Large Deployable Reflector Antennas for a New Generation of Geostationary Doppler Weather Radar Satellites

A Steering Control System to Minimize Propulsion Losses of High-Speed Containerships—Part I: System Dynamics

A Large and High Radio Frequency Deployable Reflector

A Steering Control System to Minimize Propulsion Losses of High-Speed Containerships—Part II: Controller Design

An Intelligent Industrial Arm Using a Microprocessor