Under a sky with light rain, at the construction site of the Panzhihua-Dali highway general section, white smoke rose from the asphalt pavement from time to time, and a rumbling fleet of unmanned machinery arrived from afar: a large intelligent paver leading four unmanned road rollers was constructing the combined road.
As the world's first unmanned roller machinery fleet for highway construction, it will continue until the road is built in September 2020.
The intelligent brain of this complete unmanned driving system was developed by the underground space development and utilization team and the intelligent construction team of Tsinghua University, cooperating with the Xugong Group (providing vehicles and lower control interface) and the Sichuan Road & Bridge Group (providing test conditions), after nearly two years of testing and and measuring. Having overcome many difficulties caused by the epidemic, the joint team completed the project on schedule and the unmanned road roller and the machinery fleet cooperative construction system finally met the requirements of highway construction standardization.
Panzhihua-Dali highway is an important channel for Sichuan to strengthen its ties with the Southwest and ASEAN countries, with bridges and tunnels accounting for more than 81%. The requirement of smoothness for pavement buildings is high. It is difficult for traditional manual operations to meet the requirements of construction standardization. During the process of research and development, the cooperative team paid much special attention to reducing the safety accident rate of special road construction, and decreasing the damage caused by toxic gases emitted by the asphalt concrete during heating to the human body. They together researched and developed the unmanned roller machinery fleet suitable for highway construction.
The road roller collects the surrounding environment information through a GPS positioning system, microwave communication, millimeter wave radar and other sensor equipment installed on the vehicle; plans the optimal operation path according to the environmental parameters; independently undertakes the operation, and accomplishes the unmanned multi-machine rolling and pressing collaborative work. The application of this technology has successfully made it possible for an unmanned roller to operate under complex working conditions. The construction track can be accurately controlled at 2 to 3 cm, which greatly improves the construction quality and largely reduces the cost of the operation.
Construction safety is the primary concern associated with an unmanned machinery fleet. Unmanned roller compactors are equipped with multi-level safety precautions to monitor construction conditions on the site in real time to achieve automatic warning, emergency stop, automatic entry and exit, and automatic obstacle avoidance, to provide safety protection for road construction.
With the advent of the 5G era, intelligent, unmanned, and standard mechanical construction has become a trend in industrial development. Intelligent construction aims to make full use of intelligent technology and intelligent systems to raise the level of intelligence in the construction process, reduce its dependence on people, achieve the purpose of safe construction, and improve the cost-effectiveness and reliability of construction.
This research result is a pioneering initiative to deepen cooperation in production, learning, research and application, and to fully enter the field of unmanned asphalt pavement construction. The successful application of an unmanned highway construction machinery fleet has promoted the industrialization of unmanned technology and accelerated the integrated development of smart transportation construction.
Source: Department of Hydraulic Engineering
Editor: Guo Lili, John Olbrich
