| 摘要 |
There is described a method and means for monitoring the position of an article (10) in space (that is to say the orientation of the article, its distance from a datum location and its angular movement away from an axis extending from the datum location). A number of photo-diodes (16) sensitive to infrared radiation are placed on surfaces of a cube (14) carried by the article (e.g. a headset in a virtual reality system) and an infrared radiation sensor (18) is placed at the datum location. Means in the article receive the outputs of the photo-diodes and provide in response to the level of illumination of each an output (22) indicative of the position in space of the article. To account for translational movement of the article away from the axis (Z) joining the article (10) and the datum location (18) the parts so far described may be augmented by an infrared sender (26) on the article illuminating a plurality of photo-diodes (30) located at a position spaced from the article (e.g. the datum location). A plurality of locations spaced from the article may be provided allowing a wearer of the headset freedom of movement. The outputs of the senders are modulated - demodulators (20) being provided in the means receiving the output signals of the photo-diodes. The outputs of the senders may also be polarised and polarising filters be provided in each of the photo-diodes. The effective modulation and polarisation applied to the outputs of the senders preferably differs. |
