Narrow Results

For the first time, we present a theoretical formulation to determine the nonrelativistic repulsive optical potential relative to neutron–nucleus interaction in terms of the s-wave coherent scattering amplitude and the radius of the nucleus which is regarded as a spherical infinite potential well. Within this context, the Fermi velocity is determined in excellent agreement with the Fermi velocity obtained from considerations relative to nuclear density obeying the Saxon–Woods distribution. Assuming this distribution, the force relative to the neutron–nucleus interaction is calculated. Aspects related to the involved chemical potential are discussed. Our results are consistent with previous work.

A cooperative control of a manipulator and a human operator has been proposed for an efficient direct teaching operation in this research. The main goal is making the operator be convenient and relaxed when he is operating the manipulator for a direct teaching. The proposed control strategy has two layers: In the first layer, human motion estimator (HME) has been designed to estimate a human intention. The recursive least square method has been utilized for the HME to simultaneously estimate the interaction force and the human arm admittance model. In the second layer, human motion reactor has been designed to keep the human motion intention precisely by a proportional derivative and gravity compensation in real time. Real experiments with a 3-degree of freedom robotic manipulator guided by the human operator have been conducted to draw a diamond shape on a panel. The experimental results demonstrate the effectiveness of the proposed cooperative control strategy.

We investigated the effect of the weighting between surface electromyography (sEMG) and interaction force for user intention extraction for the control of an upper-limb assistive device. A point-to-point vertical arm lifting task was performed by two age-segregated cohorts including 10 young subjects and 10 elderly subjects. The performance in terms of muscular effort and repeatability was analyzed. The elderly and young group showed age-dependent differences in terms of muscular effort with distinct sEMG weights.