Summary: | A novel algorithm for the simplified tele-operation of mobile-manipulator systems is
presented. The algorithm allows for unified, intuitive, and coordinated control of
mobile manipulators, systems comprised of a robotic arm mounted on a mobile base.
Unlike other approaches, the mobile-manipulator system is modeled and controlled
as two separate entities rather than as a whole. The algorithm consists of thee states.
In the rst state a 6-DOF (degree-of-freedom) joystick is used to freely control the
manipulator's position and orientation. The second state occurs when the manipulator
approaches a singular configuration, a con guration where the arm instantaneously
loses a DOF of motion capability. This state causes the mobile base to proceed in
such a way as to keep the end-effector moving in its last direction of motion. This
is done through the use of a constrained optimization routine. The third state is
triggered by the user: once the end-effector is in the desired position, the mobile
base and manipulator both move with respect to one another keeping the end-effector
stationary and placing the manipulator into an ideal configuration. The proposed
algorithm avoids the problems of algorithmic singularities and simplifies the control
approach. The algorithm has been implemented on the Jasper Mobile-Manipulator
System. Test results show that the developed algorithm is effective at moving the
system in an intuitive manner.
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