| 摘要 |
PURPOSE:To detect the speed of a mobile with no influence of the gravity or the receiving conditions of GPS by detecting the speed of mobile based on the high frequency components in an oscillation spectrum. CONSTITUTION:An oscillation sensor 2 disposed at the metal part a mobile, e.g. the trunk of an automobile, detects oscillation in one of back/forth and right/left directions generated through running of the automobile. An output signal S1 from the sensor is amplified through an amplifier 4 in an operating unit 3 to produce an analog signal S2 which is passed through a filter 5 in order to extract a signal S3 only in a specific band. The extracted signal S3 is fed through a detecting circuit 6 to a smoothing circuit 7 for accumulation and an analog output signal S4 therefrom is digitized through an A/D converter 8. Since only the high frequency component of oscillation detected through the sensor 2 is extracted and processed in the operating unit 3, the speed of a mobile, e.g. an automobile, can be detected with no influence of the gravitational acceleration on a slope. |
