This paper describes the features of an extended Kalman filter algorithm designed to support the navigational function of a real-time vehicle performance and emissions monitoring system currently under development. The Kalman filter is used to process global positioning system (GPS) data enhanced with dead reckoning in an integrated mode, to provide continuous positioning in built-up areas. The dynamic model and filter algorithms are discussed in detail, followed by the findings based on computer simulations as well as a limited field trial carried out in the Greater London area. The results of using the extended Kalman filter algorithm demonstrate that the integrated system employing GPS and low cost dead reckoning devices is capable of meeting the required navigation performance of the device under development.

Rhere exists a slope drifrion an integra gyro when it is used as an azimush gyro, which may cause serious heading and posirion erross in: be Inertial Navigation System (INS). Thereby, it is necessary to estimate and colmpensate ir. This paper describes its cause and characteristes. A methed of esing the output of INS after BBA CALTHRASION to estimase it and constant drift is discussed in detail. In addition. some issues needed to nore in the practical operation are provided too. Software-simniztion and practical experiment both show the valid-ty of this method.

本文设计了一种工时的动态GPS/INS组合模拟器，为测试GPS/INS组合系统考察组合系统性能提出供了一种多功能的实验设备。本文推导了GPS/INS模拟器的数学模型，谖模拟器，对本文提出的两种船用纵使方案做了比较，其中一种方案已经通过了1994年在南海进行的海上试验。实际应用表明，GPS/INS模拟器不同性能、不同工作状态下精度的GPS和惯导系统，具有较高的实用价值。