Patent ID: 8103373

Claim:
A control system for use with a machine having a tool arranged to move through a known path of movement, the control system characterised by comprising: a light emitting means arranged to illuminate a region around the path; a light receiving means arranged to receive light that has passed through the region such that objects in the region cast shadows on the light receiving means; and a processing and control means in communication with the light receiving means such that the processing and control means recognises the presence of the objects in the region by images received by the light receiving means, the processing and control means being arranged to determine the distance between the objects in or adjacent the path of the tool and a leading edge of the tool, the known path extending to a stationary member; wherein the control system includes a first mode of operation in which the processing and control means controls movement of the tool such that the distance between the objects in or adjacent the path of the tool and the leading edge of the tool is maintained within minimum and maximum values.