"Soft" Exoskeletons for Upper and Lower Body Rehabilitation — Design, Control and Testing

Abstract

The basic concepts for exoskeletal systems have been suggested for some time with applications ranging from construction, manufacturing and mining to rescue and emergency services. In recent years, research has been driven by possible uses in medical/rehabilitation and military applications. Yet there are still significant barriers to the effective use and exploitation of this technology. Among the most pertinent of these factors is the power and actuation system and its impact of control, strength, speed and, perhaps most critically, safety. This work describes the design, construction and testing of an ultra low-mass, full-body exoskeleton system having seven degrees of freedom (DOFs) for the upper limbs and five degrees of freedom (DOFs) for each of the lower limbs. This low mass is primarily due to the use of a new range of pneumatic muscle actuators as the power source for the system. The work presented will show how the system takes advantage of the inherent controllable compliance to produce a unit that is powerful, providing a wide range of functionality (motion and forces over an extended range) in a manner that has high safety integrity for the user. The general layout of both the upper and the lower body exoskeleton is presented together with results from preliminary experiments to demonstrate the potential of the device in limb retraining, rehabilitation and power assist (augmentation) operations.

Assist-as-Needed Control of an Intrinsically Compliant Robotic Gait Training Orthosis

“…PMA have intrinsic elasticity (compliance) which can be used in providing compliant actuation [41]. Several robotic orthoses powered by PMA have been developed for the gait training of neurologically impaired subjects [38,40,[42][43][44][45][46][47]. However, in most of the cases, only trajectory-tracking control has been applied to these PMA powered robotic gait training orthoses [38,48].…”

Non-linear sliding mode control of the lower extremity exoskeleton based on human–robot cooperation

“…Intuitively, the model error and disturbance are thought of the disturbance and represented by f ðtÞ which is nonlinear and difficult to model. f ðtÞ is with boundary as f L f ðtÞ f U (18) Equation (17) can be written as…”

Modeling the Static Force of a Festo Pneumatic Muscle Actuator: A New Approach and a Comparison to Existing Models

“…In recent years, pneumatic muscle actuators (PMAs, Figure 1) were integrated in many robotic systems [1][2][3][4] and are still particularly favored, especially in applications that have to be lightweight and powerful. …”