Much of the media focus on automation concerns conventional vehicles with some autonomous functions, truck convoys and low speed autonomous pods in urban areas. Full or partial autonomy of construction plant, along with operator assistance is one area where immediate improvements in safety, quality and productivity can be realised.
A 2017 report by the McKinsey group (1), identified that globally, construction sector labour productivity has increased by around 1% per annum over the past two decades compared with 2.8% globally and 3.6% for manufacturing. Increased technology certainly isn’t a silver bullet and improved business practices are needed more generally, but it can offer part of the solution.
Whilst some technologies will replace the need for human involvement, there are areas where machines can be used to assist the workers to increase productivity and performance.
Volvo have created a semi-autonomous excavator (2) which achieves perfect grading. Once the job parameters are entered into the system, the excavator automatically adjusts the boom and bucket movements to make precise cuts, follow the desired shape and deliver exactly the right angle of grade.
Volvo claim that grading times are reduced by 45% compared to conventional grading, with zero rework as the system achieves perfect results first time. An additional benefit is that a second person is not required to take depth/grade checks which also improves safety. The system also ensures that hazards are avoided through a depth limit, avoiding known underground utilities, a height limit with a pre-set safe elevation, avoiding powerlines for example, and finally, a swing fence prevents the machine hitting obstacles to its side.
An overview and assessment of potentially applicable renewable energy generation is presented in the report supplemented by a selection of case studies selected to provide a range of technologies and levels of maturity. These demonstrate the availability of technically feasible and economically viable options to support the generation of renewable energy and essentially enable PERs.
Trimble (3) report, that there are over 100,000 earth moving (dozer) vehicles fitted with machine control worldwide. Whilst semi-autonomous machines still rely on a skilled operator, technology can enable experienced operators to run 41% faster and 75% more accurately, whilst new operators will run 28% faster and 100% more accurately. Increased automation of steering and other controls is likely to improve productivity further.
There are emerging examples of connected and automated plant being deployed in the construction sector. Some are autonomous versions of existing machines, some have been developed by robotics companies to fulfil a specific need, whilst others have come from other sectors, e.g. from mining.
One area with a specific focus is in compactors, as the correct level of compaction, with an equal number of passes over each section has a strong influence on the subsequent road quality and longevity.
For road maintenance energy demands of 1 TJ/lane km (i.e. 2 TJ/km for a standard single carriageway), would require the equivalent of the annual output of around over 1,100 solar panels, for a resurfacing operation. Achieving Level 3 PER with solar technology within the right-of-way would be difficult, although possible in some locations.
BOMAG (4) has undertaken a research study to develop a fully autonomous tandem roller, containing GPS, Lidar and advanced position sensors, enabling it to be used fully autonomously in defined work areas or using remote control. BOMAG’s ‘Asphalt Manager’ software monitors compaction power and ensures that compaction performance is accurately documented.
In terms of tasks being undertaken autonomously, it is the simple repetitive tasks that will initially be replaced. A research article by Volvo construction machinery (5) states that there are some tasks, such as a skilled excavator operator, precisely and accurately controlling the bucket that are beyond the capability of current machines, however the same skilled operator is currently required to also undertake simple and repetitive tasks that a machine could ceaselessly undertake.
It is not just the ‘big ticket’ items where significant savings can be made. Traditional methods of pre-marking white lines on new construction or resurfacing involves engineers calculating the location of the new road markings, walking the route and marking out using aerosol paint or chalk. WJ (6) collaborated with a European partner to develop a small robotic system that could carry out the process autonomously. The Robotic PreMarker uses connected automated driving (CAD) software to draw where road markings need to be placed using global co-ordinates via GNSS. Once inputted the robot is then able to autonomously mark these points on the carriageway. It does this more quickly, to a greater level of accuracy, removes operatives from the carriageway (75% general reduction in exposure on site due to increased process speed) and reduces back injury risk as the process eliminated engineers constant bending when manually marking.
Whilst generating sufficient renewable energy to cover level 5 would not achievable from sources within the right-of-way, using energy generated to cover e.g. street-lighting to power electric vehicle charging stations could be a useful option for local energy use.
Discussions with an industry expert (7) suggested further levels of productivity could be achieved by remote operation of plant on certain sites, especially where they are isolated or dangerous. Operatives would sit in dedicated buildings and could potentially remotely operate plant anywhere in the UK. This would have multiple benefits; it would improve safety by removing people from site, it could encourage a wider talent pool for the sector, by engaging technologically minded operatives who would not be interested in more traditional construction roles and it would improve working conditions. Above all, it would improve productivity dramatically; a lot of time on construction is wasted, through for example, waiting for plant to arrive on site, an excavator driver waiting for haulage trucks to return. This could be avoided by allowing operatives to drive multiple machines at multiple remote locations. It won’t be suitable everywhere, but for certain locations, it would offer multiple benefits.
Will machines take jobs in construction? Probably, but this needs to be put into context. David Autor, during a TED talk on automation (8), points out that during every industrial revolution, whilst technical progress has threatened to replace jobs, for example, tractors substituting manual labour, assembly lines increasing production, computers taking over bookkeeping, employment has increased. Think of the number of IT jobs that exist now, that didn’t exist before the widespread adoption of computers in the workspace. As Autor states “As automation frees our time, increases the scope of what is possible, we invent new products, new ideas, new services that command our attention, occupy our time and spur consumption”. So, whilst some jobs will be lost, others will replace them.
7) Personal discussion with Mark Lawton, Skanska