| 摘要 |
PROBLEM TO BE SOLVED: To cope with a time lag in a GPS velocity data to calculate an accurate speed, taking a case of a different time interval in a received data into account, when calculating the speed based on the GPS velocity data and an acceleration data. SOLUTION: In this speed calculating circuit for a moving body for calculating the speed of the moving body, based on the GPS velocity data and the acceleration data of the moving body sampled at the same time in every calculation cycle, the presence of the GPS velocity data is determined in a sampling time point (step P4), and the speed of the moving body is calculated based on only the acceleration data, when the GPS velocity data is not able to be sampled concurrently with the acceleration data (step P5). When the GPS velocity data exists in the sampling time point, the speed of the moving body in the last calculation cycle is calculated based on the acceleration data sampled in the calculation cycle ago by a cycle corresponding to the time lag of the GPS velocity data (step P6). An integrated value of the acceleration data from the last calculation cycle time point up to the present time point is added to the speed at the last calculation cycle time point. COPYRIGHT: (C)2004,JPO&NCIPI |
