Fuzzy PID controller design for artificial finger based SMA actuators

Abstract

Shape Memory Alloy (SMA) wires are currently employed in robotics, as well as prosthetic limbs and medical equipment. Due to advantages such as reducing the size in the application, high power-to-weight ratio, elimination of complex transmission systems and noiseless actuation, and humanmachine interface, these materials are used as actuators in the prosthesis limb. Because of hysteresis property and nonlinear behavior of SMA, control of these actuators is very complicated. In this paper, the design of control algorithms has been discussed for SMA actuators in the artificial fingers with 3 DOF, which includes PID-fuzzy controller. Gains of controllers are set so that the current applied to SMA wires has minimum overshoot and output of system has minimal time to achieve stability. The simulation results compared with actual measured data show how well the controllers decrease the overshoot and time of stability of input signal to SMA wires.

Intelligent Controller Design for Multifunctional Prosthetics Hand

“…To determine the response based on the rate by adjusting the derivative gain. The entire weight of these three-term controller is used to adjusting the process via a feedback of control variables or an actuator such as movement of a control valve, position and speed of the robotic hand and other [10], [11].…”

Operational space control of a lightweight robotic arm actuated by shape memory alloy wires: A comparative study

“…However, it was not until recent years when the term shape memory technology (SMT) was introduced and a wide range of SMA wires' applications started to be developed. An example of these applications is the bioinspired micro-robots manufacturing, where SMAs are considered as a good alternative to traditional actuators, due to characteristics as corrosion resistance, simple mechanical structure and biocompatibility (Khodayari et al, 2011;Colorado et al, 2011;Gao et al, 2014;Shin et al, 2015). SMA wires have also been used in medical devices like intra-arterial supports (Nematzadeh and Sadrnezhaad, 2012) or wires for suturing (Nespoli et al, 2015), in orthopedic devices as a spinal cage implant , adaptive anklefoot orthoses (Mataee et al, 2015) or skeletal fixation devices (mandibular segmental) (Moghaddam et al, 2016), as well as dental and orthodontic applications (Jafari et al, 2008;Pandis and Bourauel, 2010).…”

Adaptive Control of Robotic arm with Hysteretic Joint

“…Different forms of SMA materials can be used for actuation but only the wires-type of SMA actuators will be addressed here in the current article. SMA wires are being used in medical applications [13,12], dental applications [14], automotive devices [19], SMA based motors [17], robotic manipulators [5,10,11] and other general purpose actuators [3,4,8,7,6,9]. On the other hand the design and development of SMA actuators are challenging due to low energy efficiency, slow response, hysteresis type nonlinearity which cannot be ignored and requires customized mechanical design and advanced modelling and control solutions.…”