On the implementation and control of a pneumatic power active lower-limb orthosis

Remote Actuation Systems for Fully Wearable Assistive Devices: Requirements, Selection, and Optimization for Out-of-the-Lab Application of a Hand Exoskeleton

“…Pneumatics is one of the most commonly used RAS principles for wearable assistive devices, mainly for upper-limb applications (He et al, 2005 ; Sasaki et al, 2005 ; Takahashi et al, 2005 ; Takahashi et al, 2020 ; Costa and Caldwell, 2006 ; Gordon et al, 2006 ; Balasubramanian et al, 2008 ; Beyl et al, 2008 ; Jia-Fan et al, 2008 ; Ino et al, 2009 ; Vanderhoff and Kim, 2009 ; Xing et al, 2009 ; Hurst and Aw, 2011 ; Bae and Moon, 2012 ; Heo et al, 2013 ; Huang and Chen, 2013 ; Tjahyono et al, 2013 ; Noda et al, 2014 ; Park et al, 2014a , b ; Patar et al, 2014 ; Yap et al, 2015 ; Zhao et al, 2015 ; Haghshenas-Jaryani et al, 2016 ; Chen et al, 2017 ; Sun et al, 2017 ; Yun Y. et al, 2017 ; Zhou et al, 2019 ; Ge et al, 2020 ; Hong et al, 2020 ). In the actuation unit, pneumatic energy is stored in form of highly pressurized air or generated by pumps powered by batteries.…”

“…Most frequently, conventional pressure generators or external compressed air supplies (e.g., stationary air supply systems as found in many laboratories) have been used as power sources at the input (He et al, 2005 ; Sasaki et al, 2005 ; Takahashi et al, 2005 ; Gordon et al, 2006 ; Beyl et al, 2008 ; Heo et al, 2013 ; Huang and Chen, 2013 ; Park et al, 2014b ; Patar et al, 2014 ; Zhao et al, 2015 ; Haghshenas-Jaryani et al, 2016 ; Chen et al, 2017 ; Sun et al, 2017 ; Zhou et al, 2019 ; Hong et al, 2020 ). Alternatively, compressors based on metal hydrides (MH) have been presented (Ino et al, 2009 ; Vanderhoff and Kim, 2009 ).…”

“…SPA with variable stiffness can accurately reproduce motion patterns without rigid mechanical support structures like joints or links (Yap et al, 2015 ; Zhao et al, 2015 ; Haghshenas-Jaryani et al, 2016 ; Agarwal et al, 2017 ; Sun et al, 2017 ). Double- and single-acting pneumatic cylinders are a further common type of output (Lucas et al, 2004 ; Takahashi et al, 2005 ; Bae and Moon, 2012 ; Huang and Chen, 2013 ; Patar et al, 2014 ). Cylinders can exert high bidirectional linear forces but have a limited stroke length and suffer from relatively high static friction resulting from integrated sealings.…”

“…Soft pneumatic and hydraulic actuators and artificial muscles suffer from nonlinearities, reducing the controllability, and buckling, potentially causing harmful motion for the user (Martinez et al, 2008 ). Cylinders feature high linearity due to the constant cross-section along the whole stroke length but are affected by nonlinear friction making the control challenging (Huang and Chen, 2013 ). Body-powered RAS can be considered safe since the user has direct control over the device.…”

Fractional-calculus-based control scheme for dynamical systems with input uncertainty

“…An artificial neural network control algorithm has been proposed in [10] for robotic manipulators with actuator saturation nonlinearity. A PID-iterative learning control approach for tackling the actuator nonlinearity has been designed by Huang and Chen for a biomedical device [11]. Finite-time stability synthesis of special nonlinear systems in spite of the input nonlinearity has been addressed in [12].…”