| 摘要 |
A safety system for use with a machine having a moving tool arranged to move through a known path of movement. The safety system is arranged to detect the presence of an obstruction in a region ( 20 ) around a portion of said path deemed to be hazardous. The safety system is characterised by comprising a light emitting means ( 16 ), a light receiving means ( 18 ) and a processing and control means. The light emitting means ( 16 ) is arranged to emit light generally parallel to the path of movement of the tool such that the region ( 20 ) is illuminated. The light receiving means ( 18 ) is arranged to receive light from the light emitting means ( 16 ) which has passed through the region ( 20 ). The processing and control means is arranged to receive information from the light receiving means ( 18 ) and determine whether an obstruction exists in the region ( 20 ) by the presence of one or more shadow regions cast on the light receiving means ( 18 ) by the obstruction and to control movement of the tool ( 12 ) dependent on the presence of obstructions in the region ( 12 ). |
