Operator controlled, vehicle-based highway crack-sealing machine

摘要

This paper presents a new heavy vehicle system developed for the automated sealing of cracks in highway pavement. The machine has been developed based on the authors' experience over the last twelve years building such machines, the earliest of which was reported in the first issue of this journal. The current machine overcomes the many shortcomings of the earlier machines, and this paper reports on several new contributions. A special sealant applicator that deploys a pressurised reservoir was developed to allow for high speed, automated sealing operations. In order to be able to seal cracks within a full lane without intruding into adjacent lanes, a telescoping long-reach robotic arm was developed, which can position the sealing head mounted to its end in a 3.65 m (12 ft) by 4 m (13 ft) large workspace within 0.4 mm (1/64 in) at a traverse speed up to 1 m/s (3 ft/s). To ensure adequate sealant flow, a special electrically heated hose was developed. A control network of both fast 100 Mbps Ethernet and 10 Mbps Wireless allows for distributed real-time motion control, I/O control and machine vision. A fully object-oriented, multi-threaded and Internet-based software architecture allows reliable and efficient system integration and provides an interactive and responsive user interface for feature rich and easy imaging, path planning and system control. An operator-assisted crack identification method is used and the path planning method is based on simulated annealing in order to optimally seal a network of cracks. Additionally, the overall machine's specifications are provided and test results are presented.