中文摘要：

将线元看作一个由许多无限接近的点构成的随机过程,这些点坐标的联合概率密度可以用来描述平面线元的概率,而平面线元落在某一区间内的概率,可以通过这些点在线元垂直方向的误差曲面构成的体积通过数值计算得到.采用数值积分方法计算了平面线元落在不同区间内的概率并进行模拟,最终得到平面线元误差指标和误差缓区带的合理确定方法.

英文摘要：

The line segment is regarded as a stochastic process in this paper, so the uncertainty of the llne segment is achieved and the unite probability function of points on the line segment can be used to describe the error probability of the plane line segment. Random error falling inside a certain range can be used to describe the error distribution effectively, so the probability analysis is a method for depicting the error distribution of a line segment. The probability that the line segment error fall inside a certain range can be calculated by the volume composed of the error curved surface perpendicular to the line segment. The detailed probability results of the error band of line segments are computed with numerical value, the selection principle of the error indicator and buffer of error band are then proposed.