| 摘要 |
<p>A system and method to measure the relative position and orientation of a remote body, such as a pilot's helmet (11). At least four high intensity infrared LEDs (20) positioned on the remote body are pulsed one at a time in known sequence. The LEDs are pulsed by diode drivers (27) including NMOS switches. The LEDs (20) have darkened substrates and multiple (nine) heating pads (32). A multi-element (nine), wide angle, wide aperture, short focal length lens (21) focuses pulsed light spots on a single highly linear, high resolution, two-dimensional duo lateral position sensing diode (22) having a single photoelectric sheet. Low noise transimpedance amplifiers (23) reverse bias the position sensing diode and convert the position sensing diode current signals to voltage signals, then converted by an analog to digital converter (24) to digital signals indicative of the position of pulsed light spots on the position sensing diode. A digital signal processor (25) uses the digital signals to calculate recursively the relative position and orientation of the remote body, in part by comparing calculated sensed and guessed values. Two calculation methods are disclosed for six degrees of freedom, one providing an accuracy generally of around 30 arc seconds and ideally of 3 arc seconds. Update rates of at least several hundred Hz are obtained.</p> |
