| 摘要 |
PURPOSE:To remove the individual difference of cars and drivers and estimate the arrival time of a car by finding the speed distribution consisting of the specific number of measured speeds on the basis of information from a car speed sensor in every fixed period and discriminating whether it is in a low speed mode or a high speed mode to successively compensate a set average speed. CONSTITUTION:A pulse is outputted from a car speed sensor 1 in every travelling of a fixed distance and a central processing unit CPU2 calculates the car speed on the bases of the output pulses: for example, a speed distribution mode is found in every hundred measured values (in every 200-300min), the average car speed is found from the average value of said speed distribution and the average speed is statistically calculated also from the speed distribution in accordance with either a low speed mode or a high speed mode. These speeds are compared with the preceding average speed in a storage circuit 7 or 11, and when the variation width is evaluated as a normal value, the speed is multiplied by respective compensation factors of compensation circuits 6, 10 to find a new average speed. |
