Due to high precision and convenient operation, the vision coordinate measurement machine with one probe has become
the research focus in visual industry. In general such a visual system can be setup conveniently with just one CCD
camera and probe. However, the price of the system will surge up too high to accept while the top performance hardware,
such as CCD camera, image captured card and etc, have to be applied in the system to obtain the high axis-oriented
measurement precision. In this paper, a new dual CCD camera vision coordinate measurement system based on
redundancy principle is proposed to achieve high precision by moderate price. Since two CCD cameras are placed with
the angle of camera axis like about 90 degrees to build the system, two sub-systems can be built by each CCD camera
and the probe. With the help of the probe the inner and outer parameters of camera are first calibrated, the system by use
of redundancy technique is set up now. When axis-oriented error is eliminated within the two sub-systems, which is so
large and always exits in the single camera system, the high precision measurement is obtained by the system. The result
of experiment compared to that from CMM shows that the system proposed is more excellent in stableness and precision
with the uncertainty beyond ±0.1 mm in xyz orient within the distance of 2m using two common CCD cameras.
The portable three-dimensional vision coordinate measuring system, which consists of a light pen, a CCD camera and a laptop computer, can be widely applied in most coordinate measuring fields especially on the industrial spots. On the light pen there are at least three point-shaped light sources (LEDs) acting as the measured control characteristic points and a touch trigger probe with a spherical stylus which is used to contact the point to be measured. The most important character of this system is that three light sources and the probe stylus are aligned in one line with known positions. In building and studying this measuring system, how to construct the system’s mathematical model is the most key problem called perspective of three-collinear-points problem, which is a particular case of perspective of three-points problem (P3P). On the basis of P3P and spatial analytical geometry theory, the system’s mathematical model is established in this paper. What’s more, it is verified that perspective of three-collinear-points problem has a unique solution. And the analytical equations of the measured point’s coordinates are derived by using the system’s mathematical model and the restrict condition that three light sources and the probe stylus are aligned in one line. Finally, the effectiveness of the mathematical model is confirmed by experiments.