Capturing Motion,
Crafting Stories

In order to realize the concept of sustainable development of Green Winter Olympics and improve the utilization rate of existing Olympic venues, the Winter Olympic Organizing Committee proposed to transform a number of summer Olympic venues for the Winter Olympics. The Water Cube, the swimming venue of the 2008 Beijing Olympic Games, is undergoing an unprecedented transformation. As the main venue of curling events in the 2022 Beijing Winter Olympics, it will once again witness the glory of athletes.

To transform the Water Cube into the Ice Cube, it is necessary to build a steel structure in an empty swimming pool, splice prefabricated panels on the steel frame to form a platform, then lay a waterproof layer, a thermal insulation layer, a moisture-proof layer and an anti-skid layer in turn, and then lay the ice-making pipe on it. When the refrigerant with a temperature of -18℃/-0.4℉ flows in the ice-making pipe of the whole track, the water can be frozen into ice to form a whole ice surface.

Curling track has extremely strict requirements on ice surface, even if the leveling deviation of 1mm will affect the track of curling sliding, thus changing the result of the race, which requires that the ice surface must be leveled. To form a flat ice surface, all prefabricated panels on the steel frame must be kept on the same plane.

Aiming at the above problems, the research group of Winter-Summer Scene Conversion Project of Science and Technology Winter Olympics Water Cube developed the leveling dynamic monitoring technology. The leveling dynamic monitoring technology developed by the research group is based on NOKOV optical motion capture system, which uses infrared optical cameras erected around the site to capture markers placed on prefabricated panels, thus determining the position of prefabricated panels in real time. The positioning accuracy of NOKOV motion capture system can reach sub-millimeter level, which meets the leveling accuracy requirements of precast slab.

There are 1,568 precast concrete slabs in this Ice Cube transformation project. The traditional manual leveling method is such that each leveling slab involves eight slabs around it, and the whole measurement process consumes a lot of time and manpower.

Using the dynamic leveling system based on NOKOV motion capture, the coordinates of the marker on each slab can be obtained at the same time. Put the marker in the center of the precast slab, and the system will automatically identify whether its elevation is within a reasonable range according to the set reference value. If it is within a reasonable range, it will be displayed in green; if not, it will be displayed in red instead, and the difference from the reference elevation will be displayed as well.

By observing the warning on the screen, the builders can quickly locate which board needs to be adjusted and the height that needs to be adjusted, which can be adjusted in place at one time, greatly improving the measurement efficiency. Last year, it took 45 days to complete the supporting structure of the whole structure. This year, leveling and dynamic monitoring technology was used in the construction. It took only 10 days to complete, and the construction efficiency increased by 4 times!