scholarly journals Formulating and Deploying Strength Amplification Controllers for Lower-Body Walking Exoskeletons

2021 ◽  
Vol 8 ◽  
Author(s):  
Gray C. Thomas ◽  
Orion Campbell ◽  
Nick Nichols ◽  
Nicolas Brissonneau ◽  
Binghan He ◽  
...  
Keyword(s):  
Material Handling ◽  
Task Force ◽  
Inequality Constraints ◽  
Whole Body ◽  
Lower Body ◽  
Computationally Efficient ◽  
Physical Strength ◽  
Manual Material Handling ◽  
Control Framework ◽  
Machine Interface

Augmenting the physical strength of a human operator during unpredictable human-directed (volitional) movements is a relevant capability for several proposed exoskeleton applications, including mobility augmentation, manual material handling, and tool operation. Unlike controllers and augmentation systems designed for repetitive tasks (e.g., walking), we approach physical strength augmentation by a task-agnostic method of force amplification—using force/torque sensors at the human–machine interface to estimate the human task force, and then amplifying it with the exoskeleton. We deploy an amplification controller that is integrated into a complete whole-body control framework for controlling exoskeletons that includes human-led foot transitions, inequality constraints, and a computationally efficient prioritization. A powered lower-body exoskeleton is used to demonstrate behavior of the control framework in a lab environment. This exoskeleton can assist the operator in lifting an unknown backpack payload while remaining fully backdrivable.

Lifting Performed on Laterally Slanted Ground Surfaces

2005 ◽  
Vol 49 (14) ◽  
pp. 1325-1329
Author(s):  
Zongliang Jiang ◽  
Gwanseob Shin ◽  
Jacklyn Freeman ◽  
Stephanie Reid ◽  
Gary A. Mirka
Keyword(s):  
Material Handling ◽  
Biomechanical Model ◽  
The Body ◽  
Time Dependent ◽  
Whole Body ◽  
Slant Angle ◽  
Manual Material Handling ◽  
Lateral Forces ◽  
Outdoor Work ◽  
Biomechanical Responses

Many outdoor work environments (e.g. agriculture and construction) require manual material handling activities on variable grade ground surfaces. Quantifying biomechanical responses for lifting under these conditions may provide insight into the etiology of lifting-related injuries. The aim of the current study was to quantify the effect of laterally slanted ground surfaces on biomechanical responses. Ten subjects performed lifting exertions (using a 40% of max load) while standing on a platform that was laterally tilted at 0, 10, 20 and 30 degrees from horizontal. During the lifting tasks the whole body kinematics were collected, which were later used in a dynamic biomechanical model to calculate the time-dependent moment about L5/S1 and the time-dependent lateral forces acting on the body segments. The results showed a consistent reduction in the peak dynamic L5/S1 moment (decreased by 9%) and an increase in the lateral forces (increased by 111%) with increasing slant angle.

scholarly journals Two-Dimensional Symmetric Box Delivery Motion Prediction and Validation: Subtask-Based Optimization Method

2020 ◽  
Vol 10 (24) ◽  
pp. 8798
Author(s):  
Yujiang Xiang ◽  
Shadman Tahmid ◽  
Paul Owens ◽  
James Yang
Keyword(s):  
Cost Function ◽  
Material Handling ◽  
Optimization Method ◽  
Joint Torque ◽  
Two Dimensional ◽  
Computationally Efficient ◽  
Inverse Dynamic ◽  
Manual Material Handling ◽  
Research Outcome ◽  
The Cost

Box delivery is a complicated manual material handling task which needs to consider the box weight, delivering speed, stability, and location. This paper presents a subtask-based inverse dynamic optimization formulation for determining the two-dimensional (2D) symmetric optimal box delivery motion. For the subtask-based formulation, the delivery task is divided into five subtasks: lifting, the first transition step, carrying, the second transition step, and unloading. To render a complete delivering task, each subtask is formulated as a separate optimization problem with appropriate boundary conditions. For carrying and lifting subtasks, the cost function is the sum of joint torque squared. In contrast, for transition subtasks, the cost function is the combination of joint discomfort and joint torque squared. Joint angle profiles are validated through experimental results using Pearson’s correlation coefficient (r) and root-mean-square-error (RMSE). Results show that the subtask-based approach is computationally efficient for complex box delivery motion simulation. This research outcome provides a practical guidance to prevent injury risks in joint torque space for workers who deliver heavy objects in their daily jobs.

scholarly journals A Whole-Body Control Framework Based on the Operational Space Formulation Under Inequality Constraints via Task-Oriented Optimization

IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 39813-39826
Author(s):  
Yisoo Lee ◽  
Sanghyun Kim ◽  
Jaeheung Park ◽  
Nikos Tsagarakis ◽  
Jinoh Lee
Keyword(s):  
Inequality Constraints ◽  
Whole Body ◽  
Operational Space ◽  
Control Framework ◽  
Space Formulation ◽  
Task Oriented

scholarly journals Impact of Kinanthropometric Differences According to Non-Professional Sports Activity Practiced

2021 ◽  
Vol 11 (11) ◽  
pp. 5063
Author(s):  
Daniel J. Navas Harrison ◽  
Ana María Pérez Pico ◽  
Raquel Mayordomo
Keyword(s):  
Physical Activity ◽  
Body Composition ◽  
Professional Sports ◽  
Whole Body ◽  
Lower Body ◽  
Basketball Players ◽  
Sports Activity ◽  
Sedentary Population ◽  
Activity Performance ◽  
Amateur Athlete

Kinanthropometry allows us to analyze variations in physical dimensions and body composition. This study’s objective was to evaluate the kinanthropometric differences based on physical activity performance, depending on whether the lower body or the whole body is more or less potent and the differences with a sedentary population. We analyzed 131 individuals (74 men and 57 women), with an average age of 22.68 ± 2.98 years. We differentiated three populations: sedentary (n = 63), runners (n = 20), and basketball players (n = 48). Measurements and indices were obtained following the international protocol of the International Society for the Advancement of Kinanthropometry (ISAK). The results show differences between the populations regarding weight, height, wingspan, and certain perimeters, diameters, and morphotypes depending on the predominant training type and the sedentary population. These anthropometric measurements will allow the amateur athlete to compare between seasons or other moments of training, pay attention to their evolution, and assess the possibility of changes in training.

Sign in / Sign up

Export Citation Format

Share Document