基于加速度计和磁强计的随钻姿态测量观测模型

摘要

水平定向钻进中钻具姿态的实时测量是实现导向的关键因素.推导了钻具姿态角的测量方法,给出了姿态转换矩阵的解算公式.针对姿态测量的非线性问题和已有算法的不足,建立了姿态测量系统的线性观测方程,该观测方程利用加速度计和磁强计分别测得的地球重力场分量和地磁场分量来构造新的观测向量,并以姿态四元数的误差向量作为观测模型的输入.给出了线性观测模型的求解方法,最小二乘递推法.仿真结果表明:该算法收敛速度快,能够得到钻具准确的姿态信息,即使起始姿态的估计值与真实值之间的偏差很大,该算法仍能很好地收敛到真实值.%Realtime measurements of the drill bit attitude while horizontal directional drilling are the key factors for guiding of directional drilling. A method is introduced to determine the attitude angles and the direct cosine matrix(DCM). As for nonlinear problems of attitude determination and shortcomings of the existing algorithms, linear observation equation for attitude determination system is established, which uses accelerometers and magnetometers to measure components of the earth ' s gravity field and geomagnetic field to construct new observation vectors and takes error vector of attitude quaternion as its input. A solution to the linear observation model,recursive least-squares method is proposed. Simulation results show that the algorithm converges quickly, and can get accurate attitude information, the algorithm can converge to real value, even though the deviation of estimated and real value of initial attitude is large