Development of an automated verticality alignment system for a vibro-lance

Abstract

This paper describes the automation of a vibro-lance for ground improvement on a construction site. Here, a vibrating probe is lowered into the ground and penetrates downwards by means of a two-arm excavator, compacting the surrounding soil. The control system is straightforward to install on a conventional, hydraulically controlled excavator, such as the one utilised for the field tests reported in the paper. The new system supports the operator by automatically maintaining the verticality of the probe, increasing the speed of operation by a factor of three, whilst also yielding improved accuracy and, therefore, a potential increase in tool life. In particular, the research demonstrates the successful design and implementation of Proportional-Integral-Plus (PIP) control systems for joint control on-site. To the authors' knowledge, this represents the first operational use of automation for vibro-lance ground compaction.