Local analysis of singular configurations of open and closed loop manipulators (Q1851115)

The author presents a general approach to local analysis of singular configurations of both serial and parallel manipulators. It is shown that the maximum rank deficiency of the manipulator Jacobian never has to exceed 4. Singular configurations are classified with respect to active and passive joints. The author also presents a purely algebraic algorithm which determines the singular motion of a mechanism based on its instantaneous screw system. The singular set can locally be approximated by a hypersurface of maximum degree 4. The minimum number of joints that a serial manipulator must activate in order to escape from a singular configuration is also given.