A (Non-Comprehensive) Perspective on Construction Robotics

Ruedi Wagner, Head of Open Technology Innovation, Hilti Group

In recent years, the number of robotic solutions in construction has steadily increased. At Hilti, our primary goal is to bring productivity to the jobsite. Mobile construction robots augmenting workers by taking over the strenuous, repetitive, and unhealthy tasks fall within this goal. In 2020, Hilti has launched the Jaibot, a semi-autonomous ceiling drill robot to support ceiling installations by autonomously executing measuring, drilling and marking.

As an emerging discipline, construction robotics still has a lot to learn. Yet, the increasing number of recently launched solutions may raise interest from those who have been involved in the more traditional fields of robotics. Without a claim for completeness, this article aims to share some current insights and experiences gained on jobsites around the world.

One of the main differences of deploying a robot on a manufacturing line vs a jobsite is the characteristic of the environment. A manufacturing line is usually established within a clean, structured, and controllable environment, with well-planned repetitive processes resulting in robots being fixed on the ground. Contrary to that, a construction site changes frequently, with the workplace often exposed to all the elements, people and machinery moving in rather unpredictable manners and building material often blocking the required spaces. In consequence, the automation of tasks on a construction site requires in most cases mobile, ruggedized and safe platforms with the capability of precise orientation and/or localization and a basic ability to avoid obstacles.

“Digital planning is definitely increasing also in construction. Yet, the building process with its various trades, contractors and subcontractors remains highly fragmented.”

To stay with the ceiling installation application, installations usually require an accuracy of <0.5cm. To automatically drill into the ceiling, the drill hole needs to be digitally planned, the digital plan referenced to the real jobsite, the data transferred to the robot and the drill tip needs to be localized with this accuracy in the constructed building. Today, most jobsite robots operating “under roof” and requiring such a positional accuracy, i.e. also layout robots, use surveying technologies and total stations or similar to establish an

accurate and localized reference. Robots that require “only” a high application accuracy, for instance drywalling or paint robots, do often not require digital planning, but use scanning technology to orientate themselves within the work area. For all mobile robots moving in unmapped and open terrain, safe autonomy will require relevant sensors and decision making to recognize and avoid obstacles in the pathway of the system as well as within the work area of the manipulator.

As with many emerging technologies, technology development is often ahead of the legislative framework. Some countries have recently started to develop best practices or even legal frameworks for the safe deployment of autonomous construction robots. From today’s perspective, it seems likely that construction robots will gain autonomy rather gradually, continuing to require supervising operators to take over control when needed.

Related to this, an open topic in systems design seems the use of collaborative arms (cobots), particularly when construction robots work alongside construction workers. While fencing off the active work area can also be achieved with “curtains”, cobots offer a range of safety features that are important for safe deployment within an unstructured and active construction site. With cobots being a reasonably new development of robotic technology, the portfolio of suitable cobot solutions has to date been rather limited. It will thus be interesting to see how the technology will develop with regards to safety, performance, weight and price and if regulators and certifiers reflect this in their frameworks.

As is the case with manufacturing, more planning, coordination and alignment of stakeholders along the value chain results in more productivity. Digital planning is definitely increasing also in construction. Yet, the building process with its various trades, contractors and subcontractors remains highly fragmented. This can easily dampen the productivity gains of construction robots. Fortunately, planners are increasingly taking on a coordinating role between the stakeholders to avoid collisions, delays and rework. While this is certainly good for the adoption of construction robots, it also shows once again that adoption is not just based on “technology maturity“, but also on “workflow fit”.

First steps in bringing construction robots to the market have been taken, a lot more has to be done. From today’s perspective it may be too early to say, which approach, application and solution will eventually establish itself as “Best Practice” for a robot on a construction site. But it seems clear that external factors such as a changing and often ageing labour force, increasing awareness of workers’ safety and health and the need for more sustainability will promote the use of robotic solutions across the construction industry. Exciting times ahead!

About the company: The Hilti Group supplies the worldwide construction and energy industries with technologically leading products, systems, software and services. With about 30,000 team members in over 120 countries, the company stands for direct customer relationships, quality and innovation. Hilti generated annual sales of CHF 5.3 billion in 2020. The headquarters of the Hilti Group has been located in Schaan, Liechtenstein, since its founding in 1941. The company is privately owned by the Martin Hilti Family Trust, which ensures its long-term continuity. The Hilti Group’s strategic orientation is based on a caring and performance-oriented culture and the goals of creating enthusiastic customers and building a better future.