2台の車両型移動ロボットから構成される協調搬送システムの経路追従フィードバック制御法

抄録

This paper presents a path following feedback control method for a cooperative transportation system with two car-like mobile robots coupled together by a carrier. We first define seven variables for describing the state of the system. These variables are the relative position counted as two and relative orientation of the first robot to a path followed, the first robot steering angle, the relative orientation of the carrier to the path, the relative orientation of the second robot to the path, and the second robot steering angle. We secondly transform the system into two-chain, single-generator chained form, based on Frobenius' theorem in differential geometry. This means that we make such transformation in a coordinate system where the path is a curved line axis and a straight line perpendicular to the tangent of the path is another axis. In other words, this conversion is more general because it includes a conversion performed in the Cartesian coordinate system where its two axes are straight lines and they are perpendicular to each other. One of the seven variables of the form is the moving distance of the first robot along the path. By moving the cooperative transportation system, the presented feedback control method makes the other six variables converge into desired ones, which is equivalent to making the system follow the path. Especially, the system can follow any path as long as its curvature is two times differentiable. We have performed a path following simulation where the first robot follows a circle path and the relative orientation of the carrier to the path converges into a specified angle. The validity of the transformation and the feedback control method is supported by computer simulations.