基于低成本接收机的双天线测姿算法

针对低成本接收机双天线测姿系统利用直接法解算精度较低且存在系统粗差的问题,提出一种基于载波和伪距双差实时动态定位(RTK)卡尔曼滤波算法。首先,引入基线长度作为观测量,并将事先测量得到的精确基线长度作为观测量误差;然后,根据从天线接收机的历元时间间隔对主天线位置进行实时矫正,而周整模糊度采用改进LABMDA算法求解。在静态和动态情况下进行了测试,结果表明,在基线长度为1.1m、采用GPS和北斗双系统进行观测的情况下,所提算法解算出的航向角精度在1°左右,俯仰角精度在2°~3°。相比传统的双天线直接法测姿,该算法在系统抗差性能和精度上都较优。

Dual-antenna attitude determination algorithm based on low-cost receiver

Concerning the problem that low-cost Dual-antenna Attitude determination System (DAS) has low accuracy and gross error because of using direct solution, an improved algorithm based on carrier phase and pseudo-range double-difference Real-Time Kinematic (RTK) Kalman filter was proposed. Firstly, the baseline length was employed as the observation, then the precise baseline length obtained in advance was taken as the observation error. Secondly, the position of master antenna was corrected according to the epoch time interval of the slave antenna receiver and the integer ambiguity was solved by MLABMDA (Modified LABMDA) algorithm. Experimental results in static and dynamic mode show that the accuracy of the heading angle calculated by the proposed algorithm is about 1 degree and the calculated pitch angle accuracy is about 2-3 degrees in the case of baseline length 1.1 m with GPS and Beidou dual systems. The proposed algorithm improves the robustness and accuracy of the system greatly compared with the traditional dual-antenna attitude determination by direct solution.