scholarly journals A Novel Separated Position and Orientation System Integrated with Inertially Stabilized Platform

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Yanshun Zhang ◽  
Shuangji Feng ◽  
Zhanqing Wang ◽  
Xiaopeng Xi ◽  
Ming Li
Keyword(s):  
Inertial Sensors ◽  
Orientation System ◽  
Imaging Payloads ◽  
Position And Orientation ◽  
Velocity Motion ◽  
Stabilized Platform ◽  
Application Requirements ◽  
Inertially Stabilized Platform ◽  
Centralized System ◽  
Effective Function

Considering the application requirements of independent imaging payloads design, a novel scheme of separated position and orientation system (POS) is proposed, in which the high-precision inertial sensors of traditional centralized POS fixed on the imaging payloads are mounted on three gimbals of the inertially stabilized platform (ISP), respectively, and make them integrated. Then, the kinematics model of the ISP system is built to transmit the inertial information measured by separated inertial sensors mounted on ISP gimbals and flight body to the imaging payloads, calculating the position and attitude of the imaging payloads to achieve the function of separated POS. Based on the model, a series of simulations indicate that the precision difference between separated system and centralized system is ignorable under the condition of angular motion and variable velocity motion. Besides the effective function equal to traditional centralized system, the separated POS enhances the integration with the ISP. Moreover, it improves the design independence of the imaging payloads significantly.

scholarly journals Automatic Estimation of Dynamic Lever Arms for a Position and Orientation System

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4230 ◽  
Author(s):  
Qiangwen Fu ◽  
Sihai Li ◽  
Yang Liu ◽  
Qi Zhou ◽  
Feng Wu
Keyword(s):  
Estimation Method ◽  
Measurement Unit ◽  
Valuable Insight ◽  
Differential Gps ◽  
Distribution Method ◽  
Lever Arm ◽  
Automatic Estimation ◽  
Orientation System ◽  
Position And Orientation ◽  
Stabilized Platform

An inertially stabilized platform (ISP) is generally equipped with a position and orientation system (POS) to isolate attitude disturbances and to focus surveying sensors on interesting targets. However, rotation of the ISP will result in a time-varying lever arm between the measuring center of the inertial measurement unit (IMU) and the phase center of the Global Positioning System (GPS) antenna, making it difficult to measure and provide compensation. To avoid the complexity of manual measurement and improve surveying efficiency, we propose an automatic estimation method for the dynamic lever arm. With the aid of the ISP encoder data, we decompose the variable lever arm into two constant lever arms to be estimated on line. With a complete 21-dimensional state Kalman filter, we accurately and simultaneously accomplish navigation and dynamic lever arm calibration. Our observability analysis provides a valuable insight into the conditions under which the lever arms can be estimated, and we use the error distribution method to reveal which error sources are the most influential. The simulation results demonstrate that the dynamic lever arm can be estimated to within [0.0104; 0.0110; 0.0178] m, an accuracy that is equivalent to the positioning accuracy of Carrier-phase Differential GPS (CDGPS).

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