A tool-path algorithm exhibiting improved collisional behaviour

In NC machining and photoplotting applications, tool paths are generated as offset curves. The problem of avoiding collision between tool and work in tool-path generation is described, with emphasis on the problem of generating a tool path to cut away small pieces of material. An algorithm is presented which treats collisions in the fundamental algorithm design, avoiding the danger of a cumbersome algorithm exhibiting unexpected behaviour. Improved behaviour is demonstrated in a photoplotter driver for a microwave circuit synthesis application