Dave Wilson, Motion Products Evangelist, Texas Instruments
At 6:31 a.m. on Feb. 26, if you were wearing your motor control goggles, you would have seen a bright flash in the skies over Texas. TI finally announced its long-awaited new sensorless Field Oriented Control (FOC) algorithm that it had been working on for the past couple of years. Called “TI InstaSPIN™-FOC,” this new technology promises to make FOC a lot easier to use while at the same time improving controller performance over a wider range of operating conditions. While the flash of this initial announcement is over, the motor control community will continue to feel the rumble from this big-bang for years to come!
I’m trying to think of how to communicate my excitement about this technology without sounding like a cheerleader. I’ve been in the motor control industry for 34 years. From fuzzy logic to the switched-reluctance craze of the late 90s, I have seen a lot of promising motor control technologies come and go. But in all that time, I can’t recall a technology announcement that had the potential to shake the motor control world like this one. But, enough flag waving. I will resist the urge to write using superlative phrases and grandiose keystrokes. Instead, let me bring it down to the bench level and explain why I think this announcement was so significant and why it will continue to rock the motor control world for years to come…
The first point I want to make is not related to the technology at all but how it is implemented. It is actually embedded within select C2000™ real-time control microcontrollers (MCUs) and is directly accessible as C-callable library routines. This exemplifies a growing business trend within TI to re-evaluate how we think about our products. At the last semiconductor company I worked for, I made the statement that “any processor company that still thinks its main product is silicon will be out of business within a decade.” Although my comment was not well received, I still believe it is true! In many cases, our silicon is just one component of our real product, which is our intellectual property. In my past life as a field applications engineer, having a superior piece of silicon almost always resulted in a sale. But today our customers demand more than just good silicon – they expect applications leadership and innovation. And THAT must be the prism through which we evaluate future products. I think it is safe to say that you can expect to see more innovations like this from TI in the future.
Second, TI InstaSPIN-FOC can make your job easier. A LOT easier! At the risk of overdramatizing my point, let’s just say that you can now go to your child’s music recital or sporting event after work instead of fighting with your motor control code until midnight. The research is done. The coding is done. The porting is done. All you have to do is call the functions you want. Whether you are an expert at FOC or even if this is your first motor control project, TI’s InstaSPIN-FOC can get you to the finish line much faster than trying to write the code yourself.
But even the best written code is worthless if it doesn’t perform. So let me highlight a few observations about what this technology can do for you. At the heart of TI InstaSPIN-FOC is a new sensorless engine that works like nothing I have ever seen before. You are probably aware that there are lots of different sensorless observers available today. In fact, TI has code examples of most of them already available on our website. But if you pop the hood on this engine you won’t see a sliding-mode observer. You won’t see a traditional back-EMF observer. And it doesn’t require you to inject any signals into the motor. It is something totally new. The result is a unified observer structure that works with almost any motor, over a speed range that spans over four orders of magnitude using today’s processor capabilities! We have already demonstrated practical examples of an eight-pole motor running down to five RPM without a shaft angle sensor, and a two-pole motor running up to 50,000 RPM. Unlike dual-mode observers that require extra bandwidth and mode switching between different speeds, the TI InstaSPIN-FOC observer requires no mode switching and no parameter adjustments regardless of motor speed.
We have named the observer “FAST,” which is an acronym derived from the four outputs of the observer: flux, angle, speed, and torque. Arguably, the angle estimate is the most important output since it drives the controller’s synchronous frame axis into alignment with the machine’s flux axis. It is the accuracy of this parameter that allows such elegant control over such a wide speed range. Another improvement that we have observed is how robustly the angle estimator behaves during transient conditions. While sliding mode observers we tested could easily be confused by sudden speed transients, FAST was able to track the same transients with ease.
Now that TI’s InstaSPIN-FOC has been released, don’t expect TI to just sit back and enjoy the fruits of its labor. We realize that this is a hugely competitive market, and we must continuously earn your business. To that end, we are already busy working on next-generation innovations that will enable this technology to perform even better in the future. There are many other features in TI’s InstaSPIN-FOC that I plan to address in future blogs. But for now, you can get more information about this new technology at our website.
Time will tell whether this technology really does change the motor control world. I am betting that it will. But for now, I just wanted to let you know that the sound you just heard is the collective cheer from motor control designers the world over as they just realized how easy and fun their next motor control project is going to be. :-)
Keep Those Motors Spinning,
