| 摘要 |
<p>ADAPTIVE COMPASS AND NORTH STABILIZATION DRIVE SYSTEM of the Invention This system accepts compass outputs from a wide variety of compass output devices such as stepper and synchro devices having different coupling ratios, supply voltages and carrier. frequencies. The system then, as part of a PPI radar system, electronically converts these compass outputs without the usual intermediary electromechanical devices into real-time analog reference signals properly phased with respect to the radar timing to provide an electronically stabilized PPI. This is achieved by selecting for comparison the points of equal amplitude of any two phases of gyro compass synchro output signals and using these major transition points to provide a digital code indicating the angular position of the gyro output shaft; a microprocessor then transforms the code, by comparison with a previously stored position code into coded position change signals which are then used to change a stored angular value, representing the course of the ship. These coded angular data are converted to analog sweep reference outputs applied to the deflection circuit of the display to provide a stabilized and oriented PPI display. In cases where synchro coupling ratios are used, resulting in smaller angular changes in the synchro shaft position for a given change in course, minor transition points can be inserted between the major transition points to provide the correct step changes in the orientation of the PPI.</p> |
