White Papers/Application Notes

Optimized Mechatronics for Silicon Photonics Alignments

In the rapidly growing realm of silicon photonics, precision alignment of optical components is a crucial part of the fabrication process. If a fiber-optic component is misaligned, this misalignment can prevent the device from functioning properly. Signal strength can be reduced by multiple dBs with just a single micron of misalignment, so having equipment capable of quickly and consistently performing high-precision alignments is critical for manufacturers of fiber optics and silicon photonics devices. Linear alignments are typically the most crucial in these processes, but angular alignment precision can also be very important.

Line Following in the Packaging Industry

There are many variations of line following applications within the packaging industry including labeling, cut-to-length, fly cutting, lane diversion, rotary knife, and many others. All of these line following applications have the same machine functions at their core. Commonly there is an independent moving line with feedback for measuring line speed. This feedback signal is input to the motion controller through an auxiliary encoder input. The motion controller then uses this auxiliary encoder input as the commanded speed, while it controls another axis called either a “slave” or “follower” axis to move at the same speed as the line. The relationship between line speed and follower speed could be a one-to-one ratio or some other function.

Motion Control with Precision Noncontact Displacement Sensors

Noncontact displacement sensors are used in measurement applications where surfaces or processes do not allow contact and demand high precision. Technologies such as capacitive, confocal, eddy-current, and laser triangulation sensors have proven themselves in applications that incorporate motion systems.

Aerotech’s EasyTune Advanced Autotuning Tool

EasyTune® is the most advanced autotuning tool available in a commercial motion controller. EasyTune was extensively tested and refined on different motion systems to reduce settling in order to enhanced your machine’s throughput. It allows non-control system users to complete system tuning quickly and easily.

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.

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.

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.

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.

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.

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.