In petroleum drilling,the Near-bit Inertial Measurement (NIM) uses an accelerometer triad to measure the gravity for realizing the attitude measurement.The temperature model of accelerometers needs to be calibrated in order to increase the accelerometer measurement precision in the range of working temperature.In view that traditional 12-position tumbling method has the shortcomings of time consuming and complex operation,a static no-tumbling two-position calibration method is introduced based on the analysis and modeling of the temperature characteristics of the accelerometer.The temperature compensation experiments are carried out by using the designed calibration equipment to test the temperature model of accelerometers.Experiment results show that the two-position temperature compensation method is effective and convenient,and the accelerometer precision can reach 5×10-4g within 10℃-150℃,satisfying the attitude angle measuring requirement of NIM.%近钻头惯性测量模块(Near-bit Inertial Measurement,NIM)用于石油钻井中实时测量导向外套的姿态角,是导向钻进闭环控制中的重要组成部分.它采用三轴加速度计组合测量重力加速度实现姿态角测量.为了提高加速度计在工作温度范围内的测量精度,需对其进行温漂模型标定.针对三轴加速度计组合的传统12位置翻滚温度模型测定方法存在耗时长、操作效率低的局限性,提出一种新的加速度计三轴组合温度模型标定方法——两位置法,并通过实验验证了温度补偿的效果.在10℃~150℃的温度范围内,补偿后加速度的测量精度达5×10-ag,完全满足NIM测量姿态角的要求.
展开▼