VisSim News - April 2014

Articles

VisSim for Motor Drives and Digital Power at PCIM in Nuremberg

Prof. Dr. ir. Duco Pulle, a member of TI's InstaSpin sensorless motor drive technology team, will be showing his VisSim based motor drives in the VisSim booth (Hall 7 - booth#515) at the Power Control and Intelligent Motion show at the Nuremberg Messe May 20-22. TI's InstaSpin code can also perform identification of key motor parameters like stator inductance and resistance. These parameters can change due to manufacturing variations and motor heating during use, so the ability to perform online identification is key to smooth sensorless control.

VisSim helps Bayer deliver a Better Life

Bayer's slogan is “Science for a Better Life.” Glen Williams, an engineer for the medical corporation, has been using VisSim for over a decade to fulfill that vision. While working on equipment that directly interacts with the human body in critical situations, Williams needs a precise tool to help him develop and test complex systems.

Take for example Magnetic Resonance Imaging, or MRI. “It’s an electronically noisy environment. The scanner itself generates signals that are 200 times stronger than the signal created by the human body,” says Williams.

User Matt Wolf published a VisSim model of human acid-base and fluid-electrolyte balance in the American Journal of Physiology

Dr. Matt Wolf has created a VisSim model of steady-state acid-base and fluid-electrolyte chemistry to gain further understanding and aid diagnosis of complex disorders involving cellular involvement in critically ill patients. In his latest research, a cellular compartment was added to the previous VisSim model of steady-state acid-base and fluid-electrolyte chemistry to gain further understanding and aid diagnosis of complex disorders involving cellular involvement in critically ill patients.

Meet Satya

Satya is our VisSim Application Engineer in India. As he completes his second year with VSI, it is clear his command of VisSim for Model Based Embedded Development (MBED) has grown fast. He has become quite adept in VisSim use in motor drive and digital power applications. Satya has gotten great demand for his knowlege and training skills at a number of universites in India and has been teaching one and two-day seminars quite a bit this past year. He taught a two day course at the National Institute of Technology in Warangal last October.

VisSim at San Diego State University

Dr. George Mansfield of San Diego State University has been using VisSim as an important teaching aid for his ME550 controls course for years. With enrollment of about 80 controls students per year, VisSim is used along with VisSim/Analyze to introduce students to control concepts, Bode, Root Locus and Nyquist plots.VisSim is used to validate the designs of feedback controls systems developed throughout the semester. Topics covered include modeling, simulation, linearization, Laplace, transfer functions, block diagrams, linear feedback systems, frequency domain design techniques.

VisSim Diagram of the Month

This is a diagram from Dr. George Mansfield's SDSU course. It models heat flows through the oven walls, from the heating element, heat capacities of DUT, oven, etc. PID control is used to maintain a temperature profile.
The diagram can be seen below and downloaded if you are signed in.

Puzzler

Sam was getting to be an old hand with VisSim, but ran into a problem modeling the electric steering mechanism in his solar powered car. He had carefully modeled the motor force, the frictional resistance of the wheels and linkage, integrated force over mass to get velocity and integrated velocity to get position. He even included a limit block after his velocity integral to limit the range of motion. What he noticed was that when he hit the stops and then reversed direction on velocity, there was some significant lag time before seeing any motion off the stops.