This paper summarizes the factors that limit the performance of moving-magnet galvo scanners driven by
closed-loop digital servo amplifiers: torsional resonances, drifts, nonlinearities, feedback noise and friction.
Then it describes a detailed Simulink® simulator that takes into account these factors and can be used to
automatically tune the controller for best results with given galvo type and trajectory patterns. It allows for rapid testing
of different control schemes, for instance combined position/velocity PID loops and displays the corresponding output in
terms of torque, angular position and feedback sensor signal. The tool is configurable and can either use a dynamical
state-space model of galvo's open-loop response, or can import the experimentally measured frequency domain transfer
function.
Next a drive signal digital pre-filtering technique is discussed. By performing a real-time Fourier analysis of the
raw command signal it can be pre-warped to minimize all harmonics around the torsional resonances while boosting
other non-resonant high frequencies. The optimized waveform results in much smaller overshoot and better settling time.
Similar performance gain cannot be extracted from the servo controller alone.
This paper discusses the bridging requirements and the transfer of credits for the graduates of a three year technology program entering the Bachelor of Applied Technology (BAT) degree in photonics.
The procedure followed to determine the transfer of credits consisted of two iterations. In the first iteration a detailed comparison of the learning outcomes of the different courses in the Diploma of Photonics Engineering Technology and the BAT programs was undertaken. This comparison helped to determine the correspondence of the learning outcomes, but did not permit to compare the theoretical level of the Diploma and BAT courses.
A second iteration was performed to compare in more detail the focus of the courses and the theoretical depth of learning the subjects. A grid covering all the usual mathematical topics used for the courses was set and the courses for which the mathematical tools are important were compared.
The difference between the courses from the two programs was used to design two bridging courses one in Advanced Physics and one in Advanced Optical Engineering. These two courses cover the missing theoretical background for the Diploma graduates in order to continue in the Bachelor program.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.