Active position control of a shape memory alloy wire actuated composite beam

Abstract

Abstract. This paper presents the design and the experimental result of the active position control of a shape memory alloy (SMA) wire actuated composite beam. The composite beam has a honeycomb structure with SMA wires embedded in one of its face sheets for the active actuation. The potential applications of this experiment include thermo-distortion compensation for precision space structure, stern shape control for submarines, and flap shape control for aeronautical applications. SMA wires are chosen as the actuating elements due to their high recovery stress (>500 MPa) and tolerance to high strain (up to 6%). However, SMA wires are inherently nonlinear and pose a challenge for control design. A robust controller is designed and implemented to actively control the tip position of the composite beam. The experiment set-up consists of the composite beam with embedded SMA wires, a programmable current/voltage amplifier to actuate the SMA wires, an infrared laser range sensor to detect the beam tip displacement, and a real-time data acquisition and control system. The experimental result demonstrates the effectiveness of the robust control.

A three‐dimensional model describing stress‐temperature induced solid phase transformations: thermomechanical coupling and hybrid composite applications

“…Hence, a proper choice of wire position and heating time allow to control shape and position of the structure. A wide range of appliances employing this behaviour have been proposed, such as smart wings for airplanes [15], air management modules in climate control unit, smart space antenna reflectors [16], artificial muscles [17], large bending actuators [18].…”

“…We investigate the performance of the proposed computational tool in simulating a peculiar promising application of SMA hybrid composite (active blade flap control): it has been shown [16] that helicopter blade vibration reduction is possible by trailing edge flap active control. Herein, we present a simplified model of an Aluminium flap with prestrained Ni-Ti fibres in martensitic phase surface mounted on.…”

Development of Spaceborne Deployable Active Phased Array Antennas

“…(1) 结构变形与误差对电性能的影响。关于星 载天线阵面误差方面，WANG [65] 分析了天线典型机 械误差和随机误差对天线电性能影响，并指出星载 有源相控阵天线为了获得-10 dBi 平均副瓣电平， 阵 面误差须控制在 1%波长范围以内。OSSOWSKA 等 [66] 指出星载可展开有源相控阵天线阵面变形主 要有三种--对称变形、 非对称变形和随机变形(图 11)，并分析了三种变形对天线电性能的影响。 ZULCH 等 [67] 针对美国空军和 NASA 机构研制的低 轨道 L 波段 1.25 GHz 的星载有源相控阵天线， 分析 了天线阵面变形对天线增益和对 GMTI 的影响。 (2) 电磁电路校准与补偿。TORRES 等 [68] 分析 了振动和热变形对天线电性能的影响，并通过外部 相位参考方法来校正阵元位置误差。PIERRO 等 [69] 分析了最大变形量为 10 cm 的阵面变形对中轨道星 载可展开有源相控阵天线波形和 GMTI 的影响。针 对结构变形补偿和校准技术，TAKAHASHI 等 [70] 对 星载可展开有源相控阵天线发射升空时振动和在轨 热振动导致的结构变形提出了一种补偿方法，即分 三个阶段校准：初始校准、发射前校准和在轨校准， 最后对每个阵元的相位误差进行补偿。LIER 等 [71] 针对星载 Ku 频段(17.3～17.8 GHz)有源相控阵天线 阵面变形，提出了控制电路编码校准技术。 (3) 形状记忆与自动补偿。SONG 等 [72] 将一种 形状记忆合金丝嵌入蜂窝结构体中，用于精密空间 结构的热变形补偿。 MCWATTERS 等 [73] 针对星载可 展开有源相控阵天线在轨热环境、 自身产生的热量、 卫星平台的振动和机械变形，提出了天线自动校准 和计量系统的概念，用于纠正在轨过程中的相位误 差和机械变形。PETERMAN 等 [74] [86] ，这是因为它具有如下特点：RF MEMS 不 仅可以大幅缩小相控阵天线体积，还可减轻重量； 由于 MEMS T/R 组件在低功耗方面表现突出，能减 轻相控阵扫描阵列的散热问题，延长其寿命；相比 于传统 T/R 组件，MEMS T/R 组件的插入损耗低， 故仅需要一般相控阵中 25%～50%的 T/R 组件数量 即可满足天线系统功能需要 [87] ；由于 MEMS 器件 的高线性度、宽带性能和开关高隔离度的特点，应 用 MEMS T/R 组件还能提高相控阵天线带宽、灵敏 度以及降低瞄准误差。 [51] (图 22)、单轴卷开 式展开结构(图 23)和双线轴展开结构(图 24) [90] 等三 种展开机构形式。复杂的展开机构是确保天线系统 能否正常工作的首选条件，因此应绝对保证展开机 构的可靠性。 …”

An application of neural network for Structural Health Monitoring of an adaptive wing with an array of FBG sensors

“…Taking into account the available range of various controllable properties of SMAs they can be effectively used in the active control of various static and dynamic characteristics of structural elements. For example, static deflection [4], [6], natural frequencies [5], [8], modes of vibration [2] and amplitudes of forced vibration [9] of the host structures can all potentially be changed, controlled or manipulated in a very precise manner by the use of embedded SMAs.…”