  The gesture-determined-dynamic function (GDDF) offers an effective way to
handle the control problems of humanoid robots. Specifically, GDDF is utilized
to constrain the movements of dual arms of humanoid robots and steer specific
gestures to conduct demanding tasks under certain conditions. However, there is
still a deficiency in this scheme. Through experiments, we found that the
joints of the dual arms, which can be regarded as the redundant manipulators,
could exceed their limits slightly at the joint angle level. The performance
straightly depends on the parameters designed beforehand for the GDDF, which
causes a lack of adaptability to the practical applications of this method. In
this paper, a modified scheme of GDDF with consideration of margins (MGDDF) is
proposed. This MGDDF scheme is based on quadratic programming (QP) framework,
which is widely applied to solving the redundancy resolution problems of robot
arms. Moreover, three margins are introduced in the proposed MGDDF scheme to
avoid joint limits. With consideration of these margins, the joints of
manipulators of the humanoid robots will not exceed their limits, and the
potential damages which might be caused by exceeding limits will be completely
avoided. Computer simulations conducted on MATLAB further verify the
feasibility and superiority of the proposed MGDDF scheme.
