Leaded by Professor Xu Weiguo, Tsinghua University (School of Architecture) - Zhongnan Digital Architecture Research Center, has invented the "automatic bricklaying system of machine arm". Different from the existing bricklaying system at home and abroad, it is the first time to combine automatic bricklaying of machine arm with 3D printing mortar to form an automatic integrated intelligent building system. For the first time in the world, the system was applied to the actual construction site and built a "maze garden of brick art".

Parameterization design: With the help of digital generation technology, the design of labyrinth garden firstly generates curved surface in rhino software, which looks like flowing ribbon. At the same time, optimizes the shape of curved surface, confirms that it meets the basic requirements of Space Streamline and human scale. Then the basic surface is imported into the parametric software grasshopper to analyze and arrange the bricks. Firstly, the curves of the basic surface at various heights are extracted as the baseline of each line of bricks, and then the intervals between the bricks are separated on the baseline; the dislocation between the upper and lower layers of bricks is arranged; finally, the bricks are controlled by the reference line. The vertical and horizontal dislocation perpendicular to the curve is generated to form a concave and convex texture of brick wall.

accurate conversion from digital model to actual construction: After the brick wall model is generated, the design team designs the motion trajectory of the manipulator in combination with the construction method, and uses KUKA | PRC to derive it as a program statement that can be recognized by the manipulator. The motion of the manipulator includes taking bricks with vacuum sucker, putting bricks in the specified position, turning the front end of the manipulator, printing mortar on the brick surface according to the arrangement of bricks, etc. The control command issued by the manipulator to the air pump and other external equipment is integrated in the motion track command, and the obstacle avoidance design is carried out. After the simulation in the program, the PRC program is used to execute the manipulator to realize the accurate transformation from the digital model to the actual building.

Destructive impact test: During the test stage, brick wall failure tests were carried out to verify that the brick wall design and construction specifications were satisfied. Different types of mortar are used in this wall project according to the ambient temperature. The fluidity and early strength time of mortar can meet the needs of 3D printing and molding, and can meet the different needs of winter and summer construction. Mortar used 425# cement, water cement ratio of about 0.7, strength can reach 16MPa. After the maintenance of the feet, the sandbags were used to carry out the destructive impact test, and the strength meets the requirements of the garden.Changing space: Labyrinth Garden is a circular land with a diameter of 13 meters. The three curved brick walls in the circle not only form complex and continuous folding space on the plane, but also adopt curved shape in the vertical direction. In addition, the brick walls are concave and convex in detail, so it becomes a double labyrinth of space and vision. The outer space along the circular edge is used for planting bamboo and turf, and the inner space is the place where the residents live. The relativity of Yin and Yang in Chinese tradition is presented with complexity.

The project reflects "intelligence" from design, construction to use. In the future, the intelligent city construction process needs not only intelligent perception, intelligent diagnosis, intelligent response, but also similar intelligent construction technology to make the intelligent city more comfortable.