E Drives Conference
March 2, 2008 by Steve Meyer
I was fortunate to attend the E Drives Conference In Atlanta Feb 14 & 15. The show is an annual gathering of specialty companies involved in mechatronics. The exhibits and lectures cover magnetic design tools, power electronic modules, control technology, feedback technology and gear reducers. A lot of cutting edge conversations in the mechatronic world.
The design of motion control components is a difficult balancing act. Component manufacturers must incorporate a lot of features and functionality in order to address the broadest portion of the market. For the OEM machinery builder, this often means paying more for a product that exceeds the requirements of a particular application.
It has always been my opinion that most of the available motion control products are very expensive, so I am always on the lookout for technology that offers the potential to reduce price and deliver the right kind of performance.
Two companies at the conference have standout contributions to make. One is Luminary Micro which makes high performance, low cost control chips. They are making major inroads displacing the ubiquitous DSP with more processing capability and full Ethernet and Canbus communications embedded in the same device. Very cost effective.
The other is Novatorqu, a new company that has broken some performance barriers in the electric motor. Novatorque’s President John Petro has re-invented the electric motor’s internal architecture making the DC brushless motor smaller, faster and a lot more efficient. Did I mention lower cost? Yes, lower cost too. So much so, that they think they can take on the AC motor cost point in some applications with their technology.
I hope both of these companies will succeed in growing their respective markets and recovering some of the ground we have lost to foreign suppliers.
The sad thing about the DSP craze in the motion control industry is that 90% of the things that are handled by a motion controller have nothing to do with signal processing. The only reason for such high usage of DSPs is that until in that last few years we have not had any options. DPS’ have been the only show in town and companies like TI have cashed in on it. Actually, most of the control tasks that happen in a motion controller are better handled by a microcontroller.
It is possible to say that DSPs are good for contouring calculations, but again there the reason is that they are available with fixed point or floating point capabilities at price points that are reasonable. There still no true signal processing going on.
DSPs are optimized to handled big blocks of data or data streams, and do complex calculations on it. This is not what motion control is about. Fortunately, as Steve Meyer has pointed out, there are options out there. Luminary was the first to introduce a microcontroller based on the ARM CortexM3 core, which is a very powerful core optimized for microcontrollers. Last year STMicroelectronics also introduced a product family based on this core, with even higher performance. Both have made their products very attractive to motor control. Also, compared to a lot of DSPs out there this micros can run at their maximum clock speed from flash memory and not RAM, which is the norm for most DSPs. Luminary and ST run at 50MHz and 72MHz, respectively, giving us 62 MIPS and 90 MIPS performance. More than enough for the most demanding motion control tasks at a very attractive cost (at least compared to the DSP