Highlights
Wearable Robotics
Dual-Motor-Task Analysis of Healthy Individuals
Humans perform numerous dual-tasks activities in their day-to-day activities. These activities require meeting the demand on the attentional and cognitive faculty failing in which the performance in the primary or secondary task will decline. This study provides an understanding of the gait strategy adopted by healthy individuals in order to complement the objective of the secondary task of a dual-task.
Twenty-one healthy subjects participated in this study. The experiment involved three conditions – normal overground conditions, catch and throw a ball while standing, and catch and throw a ball while overground walking – all in a virtual environment.
Results showed that although the participants walked conservatively during the dual-motor trial, the scores obtained in throwing the ball at the target were significantly high in dual-task. The lower limb gait analysis showed participants to be in the terminal and pre-swing regions of the stance phase at the throw event. During this region, the body has a forward momentum as the ankle provides power generation for the leg to begin the swing phase.
This study, being performed in virtual reality, provides a new and engaging paradigm to analyze dual-motor-task performance. It can be used as a basis to compare strategies adopted by different population groups with healthy young adults to execute coordinated motor tasks. The paper is published in the Transactions on Neural Systems and Rehabilitation Engineering (TNSRE) – 2020.
Grants: This work was done in collaboration with the ROAR Lab, Columbia University, New York as part of the Scheme for Promotion of Academic and Research Collaboration (SPARC) program, MHRD, India.
Team: Yogesh Singh, Antonio Prado, Dario Martelli, Fitsum E. Petros, Xupeng Ai, Sudipto Mukherjee, Anil K. Lalwani, Vineet Vashista, and Sunil K. Agrawal
Links: Video, Publication
Subject-Specific Gait Intervention Using WeARS
This work presents a cable-driven Wearable Adaptive Rehabilitation Suit (WeARS), which was used to implement single joint resistive force interventions at the hip and ankle joints separately. Two sets of experiments with eight healthy participants in each case were conducted. Experiment I involved the application of resistive forces on the posterior part of the thigh, and Experiment II involved the application of resistive forces on the anterior part of the foot. The resistive forces were applied from pre-swing to the terminal swing phase of walking to induce deviations in the gait pattern.
The results of the two experiments reported that the healthy participants compensated for the applied intervention by adopting a deviant gait. Significant changes in the overall gait pattern were observed, in particular, reduction in joint range of motion and ankle trajectory in the sagittal plane of walking were reported, which required significant intralimb and interlimb adjustments.
The observed results highlighted that a single-joint abnormality could result in abnormal gait characteristics, as observed in the case of multi-joint alterations. Furthermore, the results of the experiments reflected that a gait abnormality being distal or proximal can induce different spatio-temporal adaptation.
In summary, the presented work explored self-selected actions due to controlled resistive forces applied at a single joint. Such an understanding of lower limb musculoskeletal adjustments to gait abnormalities is insightful to the adaptation of human-robot interactions during gait training. Thus, locomotor adaptations studies with primitive resistive force interventions are applicable when designing effective subject-specific rehabilitation paradigms.
Team: Srikesh Iyer, Joel V Joseph, and Vineet Vashista
Links: Video, Publication
Human-Quadcopters Interaction for Aerial Transportation
HCR Lab at IITGN developed a control architecture that can enable a single human operator to fly the multiple quadcopters for the aerial transportation of the cable-suspended payload. This paper was accepted in IEEE International Conference on Robotics and Automation (ICRA) in 2020.
As a human can not control multiple quadcopters simultaneously, in the present work, a leader-follower control architecture is developed in which human flies the leader quadcopter to direct the motion of the entire system while the follower quadcopters autonomously controlled for safe and stable transportation. During the aerial transportation of the cable-suspended payload, it is necessary to control the oscillations of the cables and payload. Thus, Cable Attitude Controller (CAC) which reduces the cable oscillations and Payload Attitude Controller (PAC) which reduce the payload oscillations have been proposed.
Human experiments were conducted for two quadcopters with a cable-suspended payload and simulations were performed using three quadcopters-payload system. The results showed successful human control of these systems to transport the payload spatially.
In summary, this work presents the possibility of enabling manual control for on-the-go maneuvering of the quadcopter-payload system which motivates aerial transportation in the unknown environments.
Team: Pratik Prajapati, Sagar Parekh, and Vineet Vashista
Links: Video, Publication