Uncertainty manipulation and propagation and verification of applicability of actions in assembly tasks

Uncertainties are represented in the form of homogeneous transforms, and the manipulation of uncertainties is focused on the spatial uncertainty propagation and the uncertainty fusion. In order to integrate the uncertainty information into a task plan which consists of a sequence of primitive actions, the propagation of uncertainty before and after a primitive action, such as moving, perception, or contact action, has been developed. A simple and optimal solution for the consistency problem is proposed for perception actions. Using conditional probability and the evidence collecting technique, the correlation between motion parameters, when a contact occurs, can also be taken into account. To determine the applicability of an action, forward propagation and backward propagation are proposed to verify the success of the action in the presence of uncertainties. This backward uncertainty propagation method can be used to determine the admissible set of an action according to an acceptable success confidence