Advanced Laser Controls – Features to Improve Your Process

Untangle Your Parameters for Consistent, High-Quality Processing

Eliminating the dependency of laser processing parameters on motion trajectories improves the quality of material interactions and increases part yields. Aerotech laser control features allow users to untangle the process parameters forcing critical design compromises in many laser machining centers.  Aerotech’s Automation1 controller gives users complete control over optimized spot diameters, processing fluency, power densities, and spot-to-spot overlap without sacrificing the dynamic accuracy, throughput, or working area of your motion subsystems.

Infinite Field of View

Using Aerotech’s Infinite Field of View (IFOV) controller feature, throughput, quality, and precision can be improved in your laser machining system. With IFOV there are no limits on your laser scanner based system working area. Using the optimized optical components for your processing parameter requirements doesn’t have to limit your working area. In most contemporary laser processing systems that utilize a galvo scanner, the field size and focused spot diameter are connected through the f-theta lens selection. If a user wants a large field size to process larger parts and improve throughput, they have to compromise with a larger spot size. A larger spot size can hinder a user’s ability to make quality cuts or fine features. If the process demands a small spot size, the user is limited to a small working area and cannot achieve high-throughput. With Aerotech’s Infinite Field of View, these constraints are eliminated and you don’t have to settle for a compromised solution.

Position Synchronized Output

Aerotech’s Position Synchronized Output (PSO) feature not only improves part quality and consistency, but also allows for a more accurate part at higher throughput rates. PSO controls laser delivery in the spatial domain, allowing for pulse rate modulation as a function of the true tool-on-part velocity and position of the laser spot. This alleviates another example of process parameter entanglement existing in the interaction of the laser control system and the motion subsystem. Most motion systems only allow for the triggering of lasers in the time domain. Therefore, when the motion system needs to slow while performing tight corners to stay in tolerance, laser energy will bunch-up increasing the energy density in that section of the part. In many processes this is intolerable for quality output. The primary strategy to eliminate this is for the laser spot to maintain constant velocity on the part. However, that velocity is then dictated by the maximum velocity possible through the highest dynamic move without causing a loss of accuracy. This means throughput is diminished during lower dynamic moves where the system could be moving faster without causing accuracy issues if only the laser repetition rate increased.  

As a result of PSO, spot overlap is kept consistent throughout the motion profile, stabilizing path fluency and allowing the motion system to speed up and slow down to take full advantage of its capabilities without suffering dynamic accuracy losses. Constant and programmably variable spot overlap via PSO gives the user explicit control of laser energy density delivered to the part independent of the system dynamics, enabling better process quality control. In addition to throttling back the motion system from its full capability, traditional laser control that demands constant velocity makes the programming and motion path more complex. Often times a constant velocity constraint adds length to the overall motion path via splines added to fine features, again reducing throughput.

Power Correction Mapping

Power correction mapping ensures high quality material processing while enabling higher throughput. As discussed in the IFOV and PSO sections, achieving quality cutting in many modern materials is very sensitive to fluency. All users want to use the entire available working area of their laser delivery system as long as doing so doesn’t degrade quality. Even in scanner-based systems using IFOV, using the full working area of the scanner increases throughput of your system because it allows the scanner to do the most work during combined motion. Many optical systems, especially field flattening optics, cause spot distortion throughout the field, particularly when approaching the edges. Aerotech’s Automation1 controller allows for the creation of power correction maps to account for the distortion of the laser spot as a function of position in the field. The controller automatically manages the power output of the laser source through analog outputs as the system moves through travel to maintain a more constant fluency at the part, resulting in better quality control.

Power Throttling

Power throttling is another tool that ensures the user achieves the highest processing quality and consistency. As the power mapping function modulates laser power as a function of position, Aerotech’s Automation1 controller also allows the user to automatically scale the power output as a function of combined vector velocity of the laser spot. The faster the laser spot moves, the more power required to maintain average fluency across the cutting path. Power throttling is achieved through the Automation1’s Analog Vector Tracking, and works jointly with both PSO and Power Mapping taking all aspects of the motion into account during laser control. This is just another tool to give the user maximum control over their process parameters without compromise.