Wirtgen has released a significant software upgrade for its W series large milling machines, dubbed "Auto-Mill 3D." This system addresses one of the most persistent challenges in cold milling: maintaining a consistent texture depth and protecting the milling drum from hidden obstacles like manhole covers or reactive aggregate. Traditional milling relies on the operator to manually adjust the depth and speed based on visual cues and sensor readings, a process prone to human error.
The Auto-Mill 3D system utilizes a dual-sensor architecture. First, it employs a high-precision GNSS rover mounted on the rear of the machine that references a digital terrain model (DTM). This ensures the milling depth follows the exact design grade of the road. Second, the system integrates an infrared temperature sensor array mounted just above the drum housing. Asphalt viscosity changes with temperature; colder asphalt is harder and causes more wear on the cutting tools.
The system's "Intelligent Speed Regulation" logic works as follows: If the temperature sensor detects a cold spot (e.g., asphalt below 15°C), the system automatically slows the machine's travel speed while maintaining engine RPM. This prevents the cutting bits from shattering against the hard material. Conversely, if the asphalt is hot and soft, the system increases travel speed to maximize productivity without sacrificing surface quality.
Furthermore, the system features a "Tool Preservation Mode." The vibration sensors on the drum housing monitor the harmonic frequency of the cutting drum. If the frequency changes abruptly-indicating a hidden manhole cover-the system instantly raises the drum by 5 cm and reverses the rotation to clear the obstruction, all within 0.5 seconds. This automation reduces carbide tool consumption by 18% and minimizes costly downtime caused by damaged drum holders.
