緊耦合與鬆耦合式低成本IMU/GPS整合式POS於移動測繪應用之適用性分析

The Applicability Analysis of LC and TC Based Low Cost MEMS IMU/GPS POS for MMS Applications

近年來，整合數值影像處理與直接地理定位系統的移動測繪系統（MMS）已迅速發展。藉由直接地理定位系統可決定各時刻載具的位置與速度。全球定位系統（GPS）為提供位置導航訊息的主要來源，慣性導航系統（INS）可藉由加速度與姿態角提供所需之姿態訊息，整合GPS與INS可提升導航系統，彌補各自的缺點與限制。卡曼濾波器（KF）為INS/GPS整合系統研究中，數據處理較佳估計理論；具體實現方式包含鬆耦合（LC）與緊耦合（TC）架構。前者為將GPS的位置、速度與INS的導航訊息做整合；後者直接使用GPS之觀測量，故少於四顆衛星時亦能使用。本研究將利用LC與TC之架構，針對低成本MEMS IMU/GPS定位系統，應用在車載MMS之應用。初步實驗成果顯示，在都市地區GPS訊號遮蔽的環境下，TC比起LC有較佳的結果，故TC的高定位與定向的精度與無縫定位之特性特別適合應用於車載MMS之應用。 Mobile mapping system (MMS), the methodology that integrates digital imaging with directgeo-referencing, has developed rapidly over the past fifteen years. Global positioning system (GPS)has become the primary source of providing navigation information for most of the presentnavigation applications. An inertial navigation system (INS) is a self-contained positioning andattitude device. Integrated systems provide an enhanced navigation system with superiorperformance in comparison with either a stand-alone GPS or INS as it can overcome each of theirlimitations. The Kalman Filter (KF) has been considered as one of the most common optimalestimation tools for INS/GPS integrated kinematic POS determination. The most common INS/GPS integration is known as the loosely coupled (LC). Another type of integration is knownas tightly coupled (TC). In this research, both LC and TC integration will be utilized to analyze theapplicability for low-cost MEMS INS/GPS POS systems for MMS. The preliminary resultspresented in this research illustrate the TC have better performances than LC. Consequently, theTC INS/GPS POS system is a suitable solution to setup a low-cost INS/GPS POS system withhigher position and attitude accuracies to meet the requirement of land-based MMS application.

Mobile mapping system (MMS), the methodology that integrates digital imaging with directgeo-referencing, has developed rapidly over the past fifteen years. Global positioning system (GPS)has become the primary source of providing navigation information for most of the presentnavigation applications. An inertial navigation system (INS) is a self-contained positioning andattitude device. Integrated systems provide an enhanced navigation system with superiorperformance in comparison with either a stand-alone GPS or INS as it can overcome each of theirlimitations. The Kalman Filter (KF) has been considered as one of the most common optimalestimation tools for INS/GPS integrated kinematic POS determination. The most common INS/GPS integration is known as the loosely coupled (LC). Another type of integration is knownas tightly coupled (TC). In this research, both LC and TC integration will be utilized to analyze theapplicability for low-cost MEMS INS/GPS POS systems for MMS. The preliminary resultspresented in this research illustrate the TC have better performances than LC. Consequently, theTC INS/GPS POS system is a suitable solution to setup a low-cost INS/GPS POS system withhigher position and attitude accuracies to meet the requirement of land-based MMS application.