| 摘要 |
PURPOSE:To detect any abnormality in outputted data by finding the first running direction based on the outputted data of a geomagnetic sensor and the second running direction based on outputted data of GPS device, and when the observed absolute value of difference in directions exceeds a specified value, judging that the outputted data of the geomagnetic sensor is abnormal. CONSTITUTION:Sensor direction based on the outputted data of the geomagnetic sensor 1 and GPS direction based on outputted data from the GPS device 4 are each sought, the absolute value of the difference in directions of each detected direction is monitored, and when this absolute value of the difference in directions exceeds the specified value, judgement is carried out to decide that the outputted data from the geomagnetic sensor 1 is abnormal. Thus, when the vehicle body is magnetized by the vehicle passing through a railroad crossing, and the outputted data of the geomagnetic sensor is abnormal due to that, this fact can be detected accurately. |
