Page 42 - Power Electronics News - December 2020
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MOTION CONTROL                                                                                                                                                                                              Motion Control


                                                                                                                                 Stepper motors might seem inferior to many           form-factor, intuitive user interface, real-time

                                                                                                                                 engineers compared to servo drives. However,         capabilities, functional safety, and collecting and
                                                                                                                                 stepper motor control has come a long way from       sharing data with the cloud are the new focus
                                                                                                                                 the simple ‘no tuning needed’ control scheme.        of engineers. Quite frankly, the average engineer
                                                                                                                                 Of course, you can still drive stepper motors        might even consider motor and motion control as
                                                                                                                                 the easy way without a problem for some appli-       a necessary evil that stands in the way of his idea
                                                                                                                                 cations but an increasing number of high-end         and the conception thereof. That’s why intuitive
                                                                                                                                 applications depend on the high torque at low        development kits are key.
                                                                                                                                 speed that a stepper motor delivers. From lab
                                                                                                                                 automation to semiconductor handling and 3D          Supporting motors with development kits, un-

                                                                                                                                 printing to 4K surveillance cameras, the me-         fortunately, is not that easy. And the reason is
                                                                                                                                 chanical characteristics of these motors enable      simple: every motor is different. Motor param-
                                                                                                                                 engineers to realize drive systems without an        eters are different, the pole count is different,
                                                                                                                                 additional gearbox. And no gearbox means less        the feedback system, if any, is different, and the
                                                                                                                                 wear, less noise, and lower overhead cost.           motor might need to be optimized and finetuned
                                                                                                                                                                                      for a specific use case. And that’s not even taking
                                                                                                                                 Despite offering robustness and precision at low     the variety of external interfaces into account

                                                                                                                                 cost, stepper motors still have the reputation of    which also need to be considered. Therefore, a
                                                                                                                                 being noisy, introducing vibration, and not being    ‘one size fits all’ solution that typically consists
                                                                                                                                 very energy-efficient. A heritage from the driver    of a microcontroller with a special motor con-
                                                                                                                                 solutions used in the past which weren’t sophis-     trol library in combination with a universal driver
                                                                                                                                 ticated at all. In the meantime, however, micro-     board will not work. There are simply too many
                                                                                                                                 step operation in combination with sophisticated     variables.
                                                                                                                                 current choppers and even voltage choppers al-
                                                                                                                                 lows for smooth, noiseless operation with adap-      That’s why TRINAMIC Motion Control, now part
          Enabling Intelligent                                                                                                   tive current. Add the diagnostics features and the   of Maxim Integrated, offers a broad spectrum

                                                                                                                                                                                      of development boards as part of their modular
                                                                                                                                 advantage of no hunting – meaning no motion at
          Automation with Motor                                                                                                  all at standstill – and you suddenly have an in-     evaluation system and why the company invests
                                                                                                                                 dustry-leading solution for applications demand-
                                                                                                                                                                                      so much in the software, tools, and wizards to
                                                                                                                                 ing perfect motion control. For those applications
                                                                                                                                                                                      support this system. The boards allow quick set-
          and Motion Control                                                                                                     in need of closed-loop operation an encoder can      up of a prototype application so the average en-
                                                                                                                                                                                      gineer can try out different settings and finetune
                                                                                                                                 be added, which could be a single Hall-based
                                                                                                                                 component, to serve as a position sensor and         the drive system needed to realize their idea.
          By Michael Randt, Executive Director, Business Management at Maxim Integrated                                          you suddenly have a full-blown servo drive minus     Once the settings are perfect for their unique use

                                                                                                                                 the gearbox!                                         case, the code can easily be compiled and ex-
          Driven by increasingly lower production cost,        ier with plug-and-play building blocks offering                                                                        ported in C for direct use in their own firmware.
          BLDC motors are gaining popularity across the        field-oriented control, or vector control, in hard-               Just like motor control changed over the last two    As for the hardware, the development boards are
          board. Especially the introduction of consumer       ware. While this combination enables a whole                      decades, so did the average engineer developing      verified open-source designs under the MIT li-
          drones and e-bikes resulted in mass production       range of new applications including medical and                   the application. Nowadays, the average engi-         cense meaning they’re free to use without having
          of BLDC motors – once reserved for high-end,         healthcare devices, we should not forget about                    neer wants to focus on what makes their device       to share the result.
          industrial applications. In parallel, development    stepper motors.                                                   unique, not on developing a seemingly sophisti-
          of once sophisticated servo drives became eas-                                                                         cated drive system. Sleek designs with a minimal


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