White Papers/Application Notes

Technical Note: Piezo Controller Thermal Stability Comparison

Piezo controller design can have a significant effect on thermal stability causing excessive error in precision motion applications. In this technical note, we briefly describe some techniques used for controlling thermal effects and compare the thermal stability of our piezo control electronics with a competitive design.

High-Bandwidth Force Control

Traditionally linear stages are used with encoders to position to precise points in a motion profile. These encoders are used for both positioning and, in the case of brushless servomotors, for motor commutation as well. However, in certain applications like material press-bonding, position is not as important as force. When binding two materials together, if a position is the target, the force applied while bonding can vary significantly. Part thickness, amount of epoxy, and stage backlash can combine to produce more or less force applied than is necessary for a complete and successful bonding process. If a force can be used in place of "position" at the servo-loop level, we can be assured of the same amount of force being applied cycle after cycle, regardless of part tolerances, to create a more uniform and successful bonding result.

Machine Positioning Uncertainty with Laser Interferometer Feedback

The purpose of this discussion is to explain the major contributors to machine positioning uncertainty in systems with laser interferometer feedback near the work point. We will use an example to quantify these uncertainties in a real implementation of a laser-feedback-driven machine.

Laser Raster-Scanning Patterns on Cylindrical Workpieces Using CADFusion and PSO Bitmap Tools

A large number of cylindrical laser processing applications program the laser writing campaign as if the two axes (one linear and one rotary) are both, in fact, linear in nature. In other words, the cylindrical pattern is “unrolled” to make the shape a more typical flat workpiece. While this technique might ease the motion control programming burden, often the resulting pattern cycle time suffers due to the many directional changes the rotary axis (in particular) must undergo during laser processing. Alternatively, “free-running” the rotary axis in a constant direction and raster-scanning the required pattern using high-dynamic galvanometers is a better and far more time-efficient means of writing the same pattern to the cylindrical workpiece.

Enhanced Tracking Control (ETC)

Aerotech's unique Enhanced Tracking Control (ETC) feature improves move-and-settle times in point-to-point positioning and reduces tracking errors during contoured motion.

Synchronizing Position Synchronized Output (PSO) with Mode Locked Lasers

Many lasers are limited to firing pulses based on an internal clock source and cannot be asynchronously triggered from an external signal such as from Aerotech’s Position Synchronized Output (PSO) feature. Aerotech has added the ability to synchronize the start of the PSO output pulse with the laser clock signal.

Using the A3200 ROTATION Command for Five Axis Systems

The ROTATION command in the Automation 3200 (A3200) implements a rotation matrix operation. The function can be used to transform coordinates on mechanical actuators that include rotary motion. Multiple ROTATION commands can be configured to work with systems that have more than one rotary axis. A five‐axis system consisting of two rotary axes and three linear axes is an example of such a system. This application note will discuss the process of setting‐up the ROTATION command for this type of application.