he efferent signal is the
impulses from the brain to muscle or organ tissue. The afferent signal
is the sensation that transmits the state of peripheral body parts to
the brain. The motor control architectures of biological systems have
hierarchical structures in which the efferent/afferent signals interact.
Thanks to this architecture, flexible and reflective action is realized.
In this paper, we propose a hierarchical control architecture for high-speed
visual servoing on the basis of a biological signal interaction model.
The proposed architecture has three modules: servo, motion planner and
adaptation. The afferent signal corresponds to the feedback signal from
the sensors; the efferent signal corresponds to the motion command. These
signals interact in a hierarchical manner that realize a parameter adaptation
mechanism. A series of dynamical tasks, tracking/grasping/handling of
a moving object, is implemented as an example of high-speed visual servoing.
The system contains a DSP network, high-speed active vision, dextrous
hand and a seven-degrees-of-freedom manipulator. Real-time experiments
are conducted and the results exhibit the responsiveness and flexibility
of the proposed hierarchical architecture. |