With the progress of miniaturization, shape memory alloy (SMA) actuators exhibit high energy density, self-sensing ability and ease of fabrication, which make them well suited for practical applications. This paper presents a self-sensing controlled actuator drive that was designed using antagonistic pairs of SMA wires. Under a certain pre-strain and duty cycle, the stress between two wires bec...

This paper proposes a design of SMA-based bionic suction cup actuator, the core of which is that the bias spring cooperates with the SMA spring to produce a displacement at the varying temperature caused by the drive current. To characterize the dynamic drive performance of the actuator, the thermody‐ namic model is established by the constitutive model of SMA material of Tanaka series. The sim...

The hysteresis nonlinearity of magnetically controlled shape memory alloy actuator is an obstacle in the achievement of high positioning accuracy. To eliminate the influence of hysteresis nonlinearity, a PID hybrid control method which uses the inverse Prandtl-Ishlinskii model as a feedforward controller is proposed in this paper. The PID parameters are searched by particle swarm optimization w...

As a new actuating material, magnetic controlled shape memory alloys (MSMAs) have excellent characteristics such as a large output strain, fast response, and high energy density. These excellent characteristics are very attractive for precision positioning systems. However, the availability of MSMAs in practical precision positioning is poor, caused by weak repeatability under a certain stimulu...

Further development of a three level switching controller [3] is presented. The controller was originally designed to drive a novel Shape Memory Alloy (SMA) actuator consisting of a number of thin NiTi bers woven in a counter rotating helical pattern around supporting disks. While the original controller performed satisfactorily, it was hampered by the presence of limit cycles at higher gains. ...

Prestrainend shape memory alloys (SMA) change their length when heated above their transformation temperature. Based on this property various micro-technical actuators have been developed in the past. This paper presents the design of novel macroscopic SMA actuators scalable in force and length. Our design approach allows arranging the point of actuation in any direction and ensures a short coo...

Shape memory alloy (SMA) based actuators have the potential to be lower mass, more compact, and more simplistic than conventional based actuators (electrical, hydraulic, etc); however, one of the key issues that plagues their broad use is packaging since long lengths of wire are often necessary to achieve reasonable actuation strokes. Spooling the wire around pulleys or mandrels is one approach...

In this research a Cu-Zn-Al alloy is produced by melting the raw materials in an electric resistance furnace and then pouring it into a steel mould. The optimum way to achieve the final analysis in the hypo-eutectoid range is determined and the influence of the alloying element, Ti on the grain size and the shape memory properties of the samples are investigated. Solution treatment (done at 850...

A shape memory device, and thus the alloy, when not operating is generally held in the martensitic condition. Also the shape memory effect depends on the retransformation of the martensite to the parent phase (i). Use of an alloy in a temperature controlling device, therefore, demands reliability and reproducibility of this retransformation temperature with shape memory cycles and more particul...