This paper presents a new gravity compensation method for an upper extremity exoskeleton mounted on a wheel chair. This new device is dedicated to regular and efficient rehabilitation training for post-stroke and injured people without the continuous presence of a therapist. The exoskeleton is a wearable robotic device attached to the human arm. The user provides information signals to the controller by means of the force sensors around the wrist and the arm, and the robot controller generates the appropriate control signals for different training strategies and paradigms. This upper extremity exoskeleton covers four basic degrees of freedom of the shoulder and the elbow joints with three additional adaptability degrees of freedom in order to match the arm anatomy of different users. For comfortable and efficient rehabilitation, a new heuristic method have been studied and applied on our prototype in order to calculate the gravity compensation model without the need to identify the mass parameters. It is based on the geometric model of the robot and accurate torque measurements of the prototype's actuators in a set of specifically chosen joint positions. The weight effect has been successfully compensated so that the user can move his arm freely while wearing the exoskeleton without feeling its mass.
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http://dx.doi.org/10.1109/IEMBS.2010.5626036 | DOI Listing |
Sensors (Basel)
January 2025
College of Geoexploration Science and Technology, Jilin University, Changchun 130012, China.
As gravity exploration technology advances, gravity gradient measurement is becoming an increasingly important method for gravity detection. Airborne gravity gradient measurement is widely used in fields such as resource exploration, mineral detection, and oil and gas exploration. However, the motion and attitude changes of the aircraft can significantly affect the measurement results.
View Article and Find Full Text PDFPLoS Comput Biol
January 2025
Biorobotics Laboratory, EPFL, Lausanne, Switzerland.
Humans can perform movements in various physical environments and positions (corresponding to different experienced gravity), requiring the interaction of the musculoskeletal system, the neural system and the external environment. The neural system is itself comprised of several interactive components, from the brain mainly conducting motor planning, to the spinal cord (SC) implementing its own motor control centres through sensory reflexes. Nevertheless, it remains unclear whether similar movements in various environmental dynamics necessitate adapting modulation at the brain level, correcting modulation at the spinal level, or both.
View Article and Find Full Text PDFFront Bioeng Biotechnol
December 2024
Center for Healthcare Robotics, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Introduction: During tasks like minimally invasive surgery (MIS), various factors can make working environment not be ergonomic, and those situations will accumulate fatigue in the surgeon's muscles which will inevitably lead to poor surgical performance. Therefore, there has been a need for technical solutions to solve this problem and one of the methods is exoskeleton robots.
Methods: We designed a passive shoulder exoskeleton whose workspace could be used for MIS to assist the surgeon's movements and performed computational and clinical validation.
PLoS One
December 2024
Department of Psychology, University of Jaén, Jaén, Spain.
PeerJ Comput Sci
November 2024
University Center for Exact Sciences and Engineering, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico.
This article presents an implementation of visual servoing (VS) for a redundant mobile manipulator in an eye-in-hand configuration. We used the image based visual servoing (IBVS) scheme, which means the pose control of the robot is based on the error features in the image of a camera. Conventional eye-in-hand VS requires the inversion of a Jacobian matrix, which can become rank deficient, provoking kinematic singularities.
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