scholarly journals Sensorimotor recalibration during split-belt walking: task-specific and multisensory?

2016 ◽  
Vol 116 (4) ◽  
pp. 1539-1541 ◽  
Author(s):  
Wouter Hoogkamer ◽  
Megan K. O'Brien
Keyword(s):  
Contact Force ◽  
Movement Execution ◽  
Movement Perception ◽  
Leg Position

Motor adaptations not only recalibrate movement execution but also can lead to altered movement perception in multiple sensory domains. Vazquez, Statton, Busgang, and Bastian ( J Neurophysiol 114: 3255–3267, 2015) recently showed that split-belt walking affects perception of leg speed during walking, but not perceptions of leg position during standing and walking or perception of contact force during stepping. Considering their findings within the broader scope of sensorimotor recalibration in other tasks, we suggest that sensorimotor recalibrations are task specific and can be multisensory.

scholarly journals Split-belt walking adaptation recalibrates sensorimotor estimates of leg speed but not position or force

2015 ◽  
Vol 114 (6) ◽  
pp. 3255-3267 ◽  
Author(s):  
Alejandro Vazquez ◽  
Matthew A. Statton ◽  
Stefanie A. Busgang ◽  
Amy J. Bastian
Keyword(s):  
Motor Learning ◽  
Contact Force ◽  
Learning Task ◽  
Lower Limbs ◽  
Locomotor Adaptation ◽  
Walking Pattern ◽  
Speed Perception ◽  
Perceptual Changes ◽  
Walking Adaptation ◽  
Leg Position

Motor learning during reaching not only recalibrates movement but can also lead to small but consistent changes in the sense of arm position. Studies have suggested that this sensory effect may be the result of recalibration of a forward model that associates motor commands with their sensory consequences. Here we investigated whether similar perceptual changes occur in the lower limbs after learning a new walking pattern on a split-belt treadmill—a task that critically involves proprioception. Specifically, we studied how this motor learning task affects perception of leg speed during walking, perception of leg position during standing or walking, and perception of contact force during stepping. Our results show that split-belt adaptation leads to robust motor aftereffects and alters the perception of leg speed during walking. This is specific to the direction of walking that was trained during adaptation (i.e., backward or forward). The change in leg speed perception accounts for roughly half of the observed motor aftereffect. In contrast, split-belt adaptation does not alter the perception of leg position during standing or walking and does not change the perception of stepping force. Our results demonstrate that there is a recalibration of a sensory percept specific to the domain of the perturbation that was applied during walking (i.e., speed but not position or force). Furthermore, the motor and sensory consequences of locomotor adaptation may be linked, suggesting overlapping mechanisms driving changes in the motor and sensory domains.

BRUSHFORM 65

Alloy Digest ◽  
2013 ◽  
Vol 62 (6) ◽  
Keyword(s):  
Physical Properties ◽  
Tensile Properties ◽  
Contact Force ◽  
Temperature Rise ◽  
Power Loss ◽  
High Reliability ◽  
Superior Performance ◽  
Contact Interface ◽  
Resistive Heating ◽  
Computer Power

Abstract BrushForm 65 is designed for both superior performance and high reliability in appliance, automotive, and computer power applications. Alloy BF-65’s combination of properties limits power loss at the contact interface, controls temperature rise from resistive heating, and provides stable contact force at temperatures to 200 C (390 F). This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on forming. Filing Code: Cu-821. Producer or source: Materion Brush Performance Alloys.

Adaptive control for insect leg position: controller properties depend on substrate compliance

2004 ◽  
Vol 190 (12) ◽  
pp. 983-991 ◽  
Author(s):  
H. Cruse ◽  
S. K�hn ◽  
S. Park ◽  
J. Schmitz
Keyword(s):  
Adaptive Control ◽  
Position Controller ◽  
Leg Position

scholarly journals Evolution of a contact force network in a 2D granular assembly: an examination using neutron diffraction

2021 ◽  
Vol 23 (3) ◽  
Author(s):  
C.M. Wensrich ◽  
E.H. Kisi ◽  
V. Luzin ◽  
A. Rawson ◽  
O. Kirstein
Keyword(s):  
Neutron Diffraction ◽  
Contact Force ◽  
Granular Assembly ◽  
Force Network

scholarly journals Imitation learning-based framework for learning 6-D linear compliant motions

2021 ◽  
Author(s):  
Markku Suomalainen ◽  
Fares J. Abu-dakka ◽  
Ville Kyrki
Keyword(s):  
Contact Force ◽  
Free Space ◽  
Prior Information ◽  
Goal Area ◽  
Imitation Learning ◽  
Learning From Demonstration ◽  
End Effector ◽  
Localization Accuracy ◽  
Novel Method ◽  
Contact Tasks

AbstractWe present a novel method for learning from demonstration 6-D tasks that can be modeled as a sequence of linear motions and compliances. The focus of this paper is the learning of a single linear primitive, many of which can be sequenced to perform more complex tasks. The presented method learns from demonstrations how to take advantage of mechanical gradients in in-contact tasks, such as assembly, both for translations and rotations, without any prior information. The method assumes there exists a desired linear direction in 6-D which, if followed by the manipulator, leads the robot’s end-effector to the goal area shown in the demonstration, either in free space or by leveraging contact through compliance. First, demonstrations are gathered where the teacher explicitly shows the robot how the mechanical gradients can be used as guidance towards the goal. From the demonstrations, a set of directions is computed which would result in the observed motion at each timestep during a demonstration of a single primitive. By observing which direction is included in all these sets, we find a single desired direction which can reproduce the demonstrated motion. Finding the number of compliant axes and their directions in both rotation and translation is based on the assumption that in the presence of a desired direction of motion, all other observed motion is caused by the contact force of the environment, signalling the need for compliance. We evaluate the method on a KUKA LWR4+ robot with test setups imitating typical tasks where a human would use compliance to cope with positional uncertainty. Results show that the method can successfully learn and reproduce compliant motions by taking advantage of the geometry of the task, therefore reducing the need for localization accuracy.

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