Impedance characteristics of a neuromusculoskeletal model of the human arm II. Movement control |
| |
Authors: | Sybert Stroeve |
| |
Institution: | (1) Man-Machine Systems and Control Group, Department of Mechanical Engineering, Delft University of Technology, The Netherlands, NL |
| |
Abstract: | The modulation of neuromusculoskeletal impedance during movements is analysed using a motor control model of the human arm.
The motor control system combines feedback and feedforward control and both control modes are determined in one optimization
process. In the model, the stiffness varies at the double movement frequency for 2-Hz oscillatory elbow movements and has
high values at the movement reversals. During goal-directed two-degrees-of-freedom arm movements, the stiffness is decreased
during the movement and may be increased in the initial and final phases, depending on the movement velocity. The stiffness
has a considerable curl during the movement, as was also observed in experimental data. The dynamic stiffness patterns of
the model can be explained basically by the α−γ coactivation scheme where feedback gains covary with motor control signals.
In addition to the modulation of the gain factors, it is argued that the variation of the intrinsic stiffness has a considerable
effect on movement control, especially during fast movements.
Received: 14 October 1997 / Accepted in revised form: 18 May 1999 |
| |
Keywords: | |
本文献已被 PubMed SpringerLink 等数据库收录! |
|