Surface-based geometric modeling of general objects using teaching trees

Geometric modeling of the environment is important in robot motion planning. Generally, shapes can be stored in a database, so the elements that need to be decided are positions and orientations. In this paper surface-based geometric modeling using a teaching tree is proposed. In this modeling method, combinations of surfaces are considered in order to decide the positions and orientations of the object. The combinations are represented by a depth-first tree, which makes it easy for the operator to select one combination out of several. This method is effective not only in the case when perfect data can be obtained but also when conditions for measurement of three-dimensional data are unfavorable which often is the case in the environment of a working robot.