Abstract:Flexible exoskeletons, also known as exosuits, are robotic wearable devices intended to help healthy and unhealthy subjects in different tasks, such as daily life activities, load lifting or rehabilitation. A position control is required to assure stability and compliance in all assisted movements. In this paper, the authors propose the use of a flexible position sensor based on differential capacitance measurement as position feedback for the elbow joint in the flexible exoskeleton LUXBIT. This exosuit is con… Show more
“…Assuming that the transmission cables are not deformable, the linear speed v of the cable in the motor side is the same of the anchor-point side. Considering, for example, the shoulder cable, the cable speed is defined in terms of the shoulder actuator angular variation in (9) and in relation to the shoulder angular variation in (10):…”
Section: ) Actuator and Articular Speeds Relationshipmentioning
confidence: 99%
“…An elegant trajectory-tracking control for a rigid elbow and shoulder exoskeleton that consists on a fuzzy approximation-based adaptive backstepping controller was proposed in [8]. Position controllers for trajectory tracking in exosuits have also been used, where a SMC-based control with adaptive backlash compensation was designed for elbow control in [9]; and a supertwisting SMC was implemented for the elbow joint, obtaining high robustness to external disturbances in [10]. To the knowledge of the authors, there do not exist yet international standards regarding the required tracking accuracy for upper-limb rehabilitation.…”
Upper-limb exosuits are light wearable devices suitable for applications such as rehabilitation or assistance in industrial environments. One of the main drawbacks of these systems is the amount of uncertainties intrinsic to the nature of the device. Moreover, the direct interaction between the exosuit and its user adds disturbances to the system. Therefore, a robust control architecture to these phenomena is required for its appropriate control. In this article, a robust motion (position and speed) control architecture based on a cascade proportional-integral (PI) and a sliding mode controller (SMC), and a nonlinear disturbance observer (NDO) for the upper-limb cable-driven rehabilitation exosuit LUXBIT is designed. We call the proposed controller by the acronym CPISDO. The SMC nature allows to compensate the matched disturbances and uncertainties, while the NDO counteracts the unmatched ones. The PI component helps in reducing tracking error. Dynamic modelling, system architecture and control design are addressed. The CPISDO controller has been implemented over the exosuit and several experiments have been performed over 10 healthy subjects to evaluate the controller's tracking performance as well as the disturbance rejection. Supertwisting (a state-of-the-art SMC) and PI controllers have been implemented for CPISDO validation. Results are compared with other state-of-the-art solutions.INDEX TERMS Motion control, exoskeletons, control architectures, rehabilitation robotics, sliding-mode control.
“…Assuming that the transmission cables are not deformable, the linear speed v of the cable in the motor side is the same of the anchor-point side. Considering, for example, the shoulder cable, the cable speed is defined in terms of the shoulder actuator angular variation in (9) and in relation to the shoulder angular variation in (10):…”
Section: ) Actuator and Articular Speeds Relationshipmentioning
confidence: 99%
“…An elegant trajectory-tracking control for a rigid elbow and shoulder exoskeleton that consists on a fuzzy approximation-based adaptive backstepping controller was proposed in [8]. Position controllers for trajectory tracking in exosuits have also been used, where a SMC-based control with adaptive backlash compensation was designed for elbow control in [9]; and a supertwisting SMC was implemented for the elbow joint, obtaining high robustness to external disturbances in [10]. To the knowledge of the authors, there do not exist yet international standards regarding the required tracking accuracy for upper-limb rehabilitation.…”
Upper-limb exosuits are light wearable devices suitable for applications such as rehabilitation or assistance in industrial environments. One of the main drawbacks of these systems is the amount of uncertainties intrinsic to the nature of the device. Moreover, the direct interaction between the exosuit and its user adds disturbances to the system. Therefore, a robust control architecture to these phenomena is required for its appropriate control. In this article, a robust motion (position and speed) control architecture based on a cascade proportional-integral (PI) and a sliding mode controller (SMC), and a nonlinear disturbance observer (NDO) for the upper-limb cable-driven rehabilitation exosuit LUXBIT is designed. We call the proposed controller by the acronym CPISDO. The SMC nature allows to compensate the matched disturbances and uncertainties, while the NDO counteracts the unmatched ones. The PI component helps in reducing tracking error. Dynamic modelling, system architecture and control design are addressed. The CPISDO controller has been implemented over the exosuit and several experiments have been performed over 10 healthy subjects to evaluate the controller's tracking performance as well as the disturbance rejection. Supertwisting (a state-of-the-art SMC) and PI controllers have been implemented for CPISDO validation. Results are compared with other state-of-the-art solutions.INDEX TERMS Motion control, exoskeletons, control architectures, rehabilitation robotics, sliding-mode control.
“…A super twisting slider mode controller [29] has been simulated and implemented previously for elbow and shoulder flexion and extension movements [30]. In the study conducted previously by the authors, the use of a supertwisting controller is proposed, which stands out from other controllers in sliding mode due to its attenuation of chattering, a high frequency noise coupled to the control signals due to the discontinuous nature of SMC.…”
Section: Data Availability Statement: Not Applicablementioning
Recovery of therapeutic or functional ambulatory capacity in patients with rotator cuff injury is a primary goal of rehabilitation. Wearable powered exoskeletons allow patients to perform repetitive practice with large movements to maximize recovery, even immediately after the acute event. The aim of this paper is to describe the usability, acceptability and acceptance of a hybrid exoskeleton for upper-limb passive rehabilitation using the System Usability Scale (SUS) questionnaire. This equipment, called ExoFlex, is defined as a hybrid exoskeleton since it is made up of rigid and soft components. The exoskeleton mechanical description is presented along with its control system and the way motion is structured in rehabilitation sessions. Seven patients (six women and one man) have participated in the evaluation of this equipment, which are in the range of 50 to 79 years old. Preliminary evidence of the acceptance and usability by both patients and clinicians are very promising, obtaining an average score of 80.71 in the SUS test, as well as good results in a questionnaire that evaluates the clinicians’ perceived usability of ExoFlex.
“…Además, se ha desarrollado un exoesqueleto flexible que está equipado con una transmisión por cable en la que el par es generado por dos motores de corriente continua. Se ha simulado e implementado un controlador de modo de deslizante super twisting [14] para los movimientos de flexión y extensión de codos y hombros [15]. Finalmente, se han estudiando métodos para estimar la orientación y posición del hombro utilizando diferentes tipos de sensores y algoritmos [16][17].…”
The last decades have witnessed a rapid and vast development of robots for physical rehabilitation that allow efficient planning of the rehabilitation process in terms of cost, duration of sessions and availability of the therapist. This project aims to qualitatively evaluate an exoskeleton for upper body rehabilitation. The device presents an approach to the development of a device with the end-effector anchored to the ground that performs the actuation on an exoskeleton coupled to the body of the subject by cables. Experimentation with patients suffering from the supraspinatus tendon is documented by performing a series of movements dictated by a doctor.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.