Research On The SMA Line Actuator With DSP Control System

Shape memory alloy (SMA) actuators have great potential in niche applications, where space,weight, cost and noise are crucial factors. Despite many of the advantages, they remain mostly asexperimental actuators due to their perceived slow response speed, low accuracy and controllability.Currently, SMA actuators generally use displacement, angle and other external sensors tomeasure the feedback control, although to meet the control requirements, but the structure in thepresence of external sensors, the larger the size of the actuator, there will be more restrictive for itsapplication subject. In this thesis, practical, effective control systems are applied to achieve fast andposition control of SMA wire actuators. Basing on shape memory alloys characteristic of sensing anddriving performance, a two-way differential SMA linear actuator is designed; this paper introduces theheating circuit and the resistance signal acquisition circuit, which uses the traditional PID controllerfor the SMA actuator to improve the control effect. Specific contents are as follows:Fundamental research: study the basic concepts of shape memory alloy and its features, and doserial tests of performance parameters to get data for the next work; Then the SMA actuator isdesigned with the ball linear guide and produced it; DSP hardware control system: it includes theADC module external feedback signal processing circuit and the EV module external control heatingcircuit, and use the ORCAD software to produce the PCB board; DSP software control system: basingon CCS3.3, the control program is designed using the sub-control and traditional PID controller forthe SMA actuator to improve the control effect. According to the conclusions of experiments, it isverified that the actuator and control system is feasibility and controllability.