绝对二次曲面

To solve the problem, the method that all the elements of the image of dual absolute quadric are transformed into the same magnitude is proposed.

提出了一种变换法，使对偶绝对二次曲面像的各个元素变到同一个数量级上，可以使求解过程更具有鲁棒性。

An analysis on camera critical motion is given and a conclusion is proposed which clarifies that the critical motion is decided by the ambiguities of the absolute quadric.

通过对相机的临界运动进行分析，指出了相机运动的关键性在于绝对二次曲面求解的模糊性这一结论。

The available camera self-calibration is based on the image of the dual absolute quadric, but its elements have so large differences in magnitude that solutions are extremely sensitive to noise.

现有的自定标技术一般都是基于对偶绝对二次曲面像，由于对偶绝对二次曲面像元素在数量级上相差较大，在求解时必然会导致鲁棒性较差。

Theory; the spatial meshing theory includes comparative motion, comparative differential and conjugative curved surface; and the application of meshing theory includes gear drive and worm drive. The spatial meshing theory is the main part of the course.

课程的重点讲解内容有曲线的参数方程、切线、法面、弧长、曲率、空间曲线的基本公式、挠率及平面曲线的基本公式等；曲面第一和第二基本公式，法曲率、主方向和主曲率、欧拉公式、短程挠率、欧拉公式和贝特朗公式推广、相对法曲率和相对短程挠率等；刚体的绝对和相对运动速度、相对微分和绝对微分、相对速度和相对微分、轨迹曲面的法曲率和短程挠率等；空间共轭曲面的啮合条件、诱导法曲率、两类界限点、等距共轭曲面、空间啮合的二次接触原理等；蜗杆传动的数学模型建立及啮合特性分析方法等。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。