Minimizing the number of iterations when computing a base pose for manipulation by mobile base inclusion in the inverse kinematics

One of the most fundamental skills of a domestic service robot is the ability to manipulate objects. Hereto, the end-effector must be positioned accurately in Cartesian space. To move the end-effector to its desired pose, a suitable end-pose for the mobile platform and a corresponding configuration of the manipulator and possibly torso must be found. To determine the optimal base pose, it is common to compute manipulator configurations corresponding to a large number of possible base poses, requiring a large number of IK computations with each a number of samples or iterations with corresponding time-consuming collision checks. This paper demonstrates how the total number of required iterations can be minimized by computing a single IK solution for the kinematic chain including the base kinematics and using the result as the base pose for manipulation. As a secondary objective, the distance to joint limits is maximized. A further reduction in the total number of iterations can be achieved by only constraining translations and rotations that need to be constrained for the task at hand.