| 摘要 |
1500970 Line followers LEAR SIEGLER Inc 3 July 1975 [16 July 1974] 28101/75 Heading G1A [Also in Division G3] In a vehicle guidance system in which a vehicle is made to follow a line which it illuminates, the line includes a material which emits a first wavelength when illuminated by a second wavelength. The line may be fluorescent, in which case the illumination is ultraviolet and the emission from the line is visible; the source of illumination is filtered to provide only UV and the photo-detectors of the system are filtered or otherwise selected to respond only to appropriate visible wavelengths. The source may be modulated to ease detection of the fluorescence by synchronous demodulation, and various AGC and other circuits are proposed to counter background illumination and to prevent operation in the absence of a line. In Fig. 2 a UV source 50 emits radiation on to line 36, all visible emission being blocked by filter 52. Detectors 56, 58, 60 respond only to fluorescence passed by filters 61, and their signals are processed to derive a position error signal, Fig. 3 (not shown). This is used to adjust the steering of the vehicle. A floor scrubber is described to which the guidance system may be applied; a modification allows the system to be used with scrubbers steered by their front or rear wheels.
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