| 摘要 |
PURPOSE:To eliminate the difference between a display spot and an actual arrival spot by comparing sensor outputs with a maximum and a minimum value during last correction and detecting a magnetization correction period, and sending an indication to a driver. CONSTITUTION:An arithmetic control part 6 compare the maximum and minimum values of an (x)-directional and a (y)-directional terrestrial magnetism component and this operation is repeated until the output signal of a correction end switch 8 is supplied to the arithmetic control part 6. Then, the arithmetic control part 6 calculates an (x)-directional and a (y)-directional correction coefficient and the (x)-directional and (y)-directional maximum and minimum values are stored as maximum and minimum values for comparison. When the pulse output of a vehicle speed sensor 1 is supplied to the control part 6 through a waveform shaping circuit 7 after corrections are made, the (x)-directional and (y)-directional maximum and minimum values are compared. When the values in two directions are within a specific range, corrections are made in the two directions and the direction and run distance are calculated to detect the current position, which is decomposed into two-dimensional coordinates and displayed on a display device 9, thus eliminating the difference from the actual arrival spot. |
