A task-based design methodology for robotic exoskeletons

Abstract

Introduction This study is aimed at developing a task-based methodology for the design of robotic exoskeletons. This is in contrast to prevailing research efforts, which attempt to mimic the human limb, where each human joint is given an exoskeleton counter-joint. Rather, we present an alternative systematic design approach for the design of exoskeletons that can follow the complex three-dimensional motions of the human body independent of anatomical measures and landmarks. With this approach, it is not necessary to know the geometry of the targeted limb but rather to have a description of its motion at the point of attachment. Methods The desired trajectory of the targeted limb has been collected through a motion capture system from a healthy subject. Then, an approximate dimensional synthesis has been employed to specify the size of the mechanism and its location with respect to the limb, while generating the desired trajectory. The procedure for this method, from motion capture to kinematic synthesis to mechanism selection and optimization, is validated with an illustrative example. Results The proposed method resulted an exoskeleton which follows the desired trajectory of the human limb without any need of aligning its joint to the corresponding human joints. Conclusion A method to design lower mobility exoskeletons for specific sets of human motion is presented; the approach result an exoskeleton with lesser actuation system while generating complex 3D limb motions, which in turn results a lighter exoskeletons. It also avoids a need to align each robotic joint axis with its human counterpart.

Methodology for a Task-Specific and Personalised Development of an Initial Exoskeleton Design

“…As stated before, a systematic approach will improve the overall development process (Hansen et al, 2018). Existing methodologies for exoskeletons focus either on the iterative prototype design phase (Dahmen and Constantinescu, 2020;Constantinescu et al, 2018) or on the specifics of a single task within the development process while neglecting the overall design process (Heidari et al, 2018;Hansen et al, 2018). However, a methodology for the development of an initial conceptual exoskeleton design specific to a particular application remains unknown.…”

“…The third phase (evaluation) is specific for the development of rehabilitation devices. Heidari et al (2018) propose a task-based design methodology for the development of exoskeletons. This method is based on a detailed assessment of the human body movements as well as an identification of body movement paths instead of considering the human (robotic) joint movements.…”

“…The engineering phase can be applied to the iterative prototype design phase by providing further specifying steps to design the initial prototype. The third phase (evaluation) is specific for the development of rehabilitation devices Heidari et al (2018). propose a task-based design methodology for the development of exoskeletons.…”

Design Methodology for Rehabilitation Robots: Application in an Exoskeleton for Upper Limb Rehabilitation

“…These characteristics of the developments of rehabilitation technologies have results into the appearance of different methodologies approaches to create therapies devices, in [6] describes a methodology for design an exoskeleton using a motion capture system of the trajectory of the limb from a healthy subject, for rehabilitation's devices are important to define the specifications to calculate the design parameters of the actuator, the number of elements and the characteristics of the material [7], the development of multidisciplinary technological devices requires a holistic methodology for planning, optimization and integration of human-centered workplaces [8], as aforementioned each of the methodologies work like a sequence of steps but do not use the clinical context and a specialist from different disciplines working concurrently from the beginning of the design.…”

Methodology for the Design of Rehabilitation Robots: Application in an Exoskeleton for Upper Limb Rehabilitation

“…These characteristics of the developments of rehabilitation technologies have results into the appearance of different methodologies approaches to create therapies devices, in [6] describes a methodology for design an exoskeleton using a motion capture system of the trajectory of the limb from a healthy subject, for rehabilitation's devices are important to define the specifications to calculate the design parameters of the actuator, the number of elements and the characteristics of the material [7], the development of multidisciplinary technological devices requires an holistic methodology for planning, optimization and integration of human-centered workplaces [8], as aforementioned each of the methodologies work like a sequence of steps but do not use the clinical context and a specialist from different disciplines working in a concurrently way from the beginning of the design.…”