Brake safely when it counts

Emergency Brake Assist actively reduces the workload in tough work environments

The construction machinery manufacturer BOMAG is equipping its heavy tandem rollers with the Emergency Brake Assist* safety system from SICK. The system, which prevents collisions with people and infrastructure, is precisely tailored to the machine type and the specific application and is the most technologically advanced solution on the market at present. The feedback from industry for this innovative safety solution has consistently been very positive.

Noise, heat, steam and a latent accident risk – who wouldn't tip their hat to the workers as you drive past highway construction sites? The drivers of the mighty asphalt rollers, in particular, perform a tough job. They not only need to pay close attention to the edges of the roadway, but also keep an eye on the audiovisual signals for the fuel and water level as well as indicators of the degree of compaction of the asphalt within their cockpit. Added to this, there is the constant challenge of managing potentially hazardous situations for the people and materials in the construction site area. All this translates to not only mental but also physical stress, which experts determine as the primary cause for accidents on construction sites.

New approach with active anti-collision

To-date, reversing cameras or 360-degree cameras for environment detection have been employed to assist drivers, however BOMAG decided to take a different approach when equipping its latest generation of the AP-5 heavy tandem roller: "We purposely decided against selecting a camera for collision avoidance so as to make life easier for the driver. The system is intended to operate in the background and only intervene when necessary," emphasizes Frank Reinartz, the person responsible for product management for heavy tandem rollers at BOMAG.

Back at BAUMA 2019, the experts from SICK and BOMAG discussed the urgent problem of safe collision avoidance for mobile machines in outdoor applications under challenging conditions. Having worked on achieving the autonomous operation of asphalt rollers, BOMAG presented there a highly acclaimed technology study with its ROBOMAG. This system, too, was already equipped with the LiDAR sensor technology from SICK. With its now series production ready collision prevention system – Emergency Brake Assist – the technology leader in the construction machinery sector has achieved an important milestone.

USP: dynamic route calculation combined with functional safety

The EN ISO 13849-1-certified safety system achieves performance level b and reduces the workload on the driver by actively applying the brakes. Under harsh ambient conditions, it uses two 3D LiDAR sensors for environmental perception to measure the travel path of the machine taking into consideration the precise steering angle and the speed of travel. The sensors for this are mounted on the front and rear of the cabin roof. Using a central processing unit that combines all the measurement data of the LiDAR sensors and the machine controller based on intelligent algorithms, the distance between the roller and emerging obstacle is determined. The system detects both static and dynamic obstacles, e.g., people, other machines, or objects in the infrastructure.

At the same time and with the help of dynamic route calculations, the safety system only "takes notice of" actually relevant obstacles so as not to curtail the productivity of the driver. If the driver is distracted or there is a risk of an obstacle being overlooked, the system automatically initiates an adaptive application of the brakes. While previous assistance systems have not been well accepted by drivers, the feedback on the Emergency Brake Assist feature in the new pivot-steered tandem rollers at BOMAG has been decidedly positive, as Frank Reinartz emphasizes: "We have been receiving consistently good feedback from our first customers – in particular regarding the intuitive operation and noticeable reduction of workload in complex construction site situations.

"A system that really helps customers!"

BOMAG and SICK developed the system through an intensive co-engineering effort. Tilman Schmidtke, Strategic Product Manager Mobile Outdoor Automation at SICK, regards the following as the main reason for success: "In weekly meetings, we jointly refined the system step by step with the help of comprehensive field tests and iterative improvement loops. For example, the steam produced when sprinkling the drums with water initially caused our optical LiDAR sensor problems. We then built a smart software-based filter that recognized these steam clouds. The continuous and direct feedback was incredibly valuable to us as it enabled us, thanks to our agile team-based working method, to jointly develop with BOMAG in the end a system that both achieves performance level b according to EN ISO 13849-1, and, when mounted on the roller, passed with flying colors the tests according to the test principle GS-BAU-70 of the German Social Accident Insurance Institution for the Construction Industry (BG Bau)."

Frank Reinartz adds that the precise adaptation of the system to the specific application in question paid off, and he draws a clear conclusion: "With this focused and quite time-consuming development work, we have created for our new generation of heavy tandem rollers (types BW 154 AP-5 / BW 174 AP-5) a system that functions well and reliably, and which really helps customers in their daily work on the construction site, in particular with avoiding accidents."

Emergency Brake Assist can, of course, also be adapted to the particular work situation, for example when a grit spreader is attached to the roller to improve the surface adhesion after asphalt paving. The changed circumstances are automatically detected by the system and taken into consideration in the environment monitoring.

International recognition: safety that is setting the standard

The innovativeness of Emergency Brake Assist has also gained great international recognition. At the Intermat in Paris in 2024, the system received the Gold Award for Innovation for its groundbreaking technology for the automatic detection of obstacles and emergency braking. In its decision, the independent international panel of judges acknowledged in particular the contribution of the system to increasing occupational safety on the construction site as well as its technological maturity. The decisive criteria therefore were the precise object detection by means of multi-level LiDAR, the automatic braking strategy, and the ease of integration into existing machine concepts. This award underscores the great importance of intelligent assistance systems such as Emergency Brake Assist to the future of road construction because it is also suitable for road milling machines, mobile robots in outdoor applications, cranes or telehandlers.

Tailored sensor solution – even for trench rollers

BOMAG is also relying on smart sensor technology for its BMP8500 multipurpose compacter – in particular in the form of a customer-specific, customized inertial sensor of type TMS/TMM22. The sensor reliably detects critical tilt angles, as can arise when using the compacter on uneven terrain, and ensures the hydraulic unit is switched off in the event of an emergency. This prevents the machine from running dry and suffering irreparable damage if it tips over.

Standard solutions hit their limits in this case because extreme vibrations and shocks in the operating environment have made precise detection impossible to-date. Through an on-site performed firmware update, the sensor was able to be optimally tailored to the requirements – a prime example of practical engineering. This demonstrates that safety is not just a matter of technology, but also adaptation to real-life conditions.

* This product is listed under the name *Safe Brake Assist at SICK.

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