Embedded solutions for motor control have historically been a big part of what
we do at NXP—going all the way back to some of our Motorola product
lines. In the past, motor control applications have typically relied on the
affordable and flexible usability provided by microcontrollers (MCUs). While
there are still many situations where the simplicity of an MCU offers a
perfect fit, there are increasingly more motor control instances that would
benefit from greater performance and integrated functionality at the
This is really part of a more general trend across the industrial and consumer
markets. Product designers want efficient, high-performance embedded
processing with greater wireless connectivity, better display capabilities,
dedicated image capture and increased data processing power, without
increasing costs and power consumption, which will bring the motor control
applications to higher integration, smarter and more harmonic level.
Essentially, they need something that covers the space between MCUs and more
fully featured applications processors (MPUs).
i.MX RT Motor Control Features
Arm Cortex-M7 core, up to 600 MHz (0-95C) or 500MHz (-40-105C)
- 32 KB L1 instruction cache and 32 KB L1 data cache
Up to 512KB on-chip RAM that can be configured as I-TCM and
D-TCM or general-purpose on chip RAM
4 x FlexPWM
- 4 sub-modules with A, B, X PWM outputs in each FlexPWM
Separated 16-bit counter for center, edge-aligned and
asymmetrical PWMs for each sub-module
All 4 FlexPWM are easily configured to work in synchronous mode
- Multiple output h/w triggers generated per PWM cycle
2 x 12-bit ADC with up to 1MS/s sampling rate and 16 input channels
selected by h/w or s/w triggers
ADC_ETC to share an ADC in a time-division-multiplexing way and to
sync trigger between trigger initiator and ADC
4 x QuadTimer with Quadrature decoder integrate
With 4 identical 16-bit counter/timer groups in each QTimer
- Each support standard capture and compare operation
4 x 32-bit PIT for periodical interrupt generation
2 x 32-bit GPT with 2 input capture Channels and 3 output compare
- 4 x Quadrature Encoder/Decoder
4 x ACMP with 6-bit DAC and two 8-to-1 channel mux
3 x XBAR and 2 x AOI for module inter-connectivity
The Crossover between Performance and Usability
As a leading producer of both MCUs and MPUs, NXP was up to the challenge of
filling this need in the market. Our new
i.MX RT Crossover series (based on the ARM®
Cortex®-M7 core) bridges the gap between performance and usability for
today’s industrial and consumer markets—including
next-generation motor control designs. The i.MX RT supports up to a four-AC
motor control system with unique features including:
- Two sensorless FOC motors control + Camera + LCD preview
Four high-speed, sensorless FOC electronic speed controllers for UAVs
Servo motor actuators (PMSM and stepper motor), which are used in 4-axis CNC
milling or 3D printers (XYZ head with additional motor for 3D printing
- And other systems up to 4 advanced AC motors control
Industrial Controls—Higher performance and integrated capabilities
The i.MX RT processor enables
enhanced automation capabilities for a variety of industrial
control applications—such as robotic arms, product assembly,
manufacturing and secure physical access.
For example, within an automated parking garage system, the i.MX RT includes a
parallel camera sensor interface and image processing capabilities for reading
license plate numbers and determining whether or not to allow access based on
that data. If the license plate scan shows the car belongs to an authorized
vehicle, then the chip automatically operates the necessary motors to open and
close a garage door, gate, and/or other secure barriers.
In addition, the i.MX RT’s integrated multimedia
features—supporting GUI displays, enhanced touch capabilities and
audio—can help improve other types of industrial operations through
advanced Human Machine Interface (HMI) capabilities.
The combined features and capabilities of i.MX RT processors also enable
designs that achieve higher performance at lower cost. That
means boosting capabilities while reducing complexity and bill-of-materials
(BOM) expenses at scale across your installed industrial base.
With i.MX RT, you can get increased performance without needing to purchase
more expensive applications processors or the complexity of moving into the
Linux space. Crossover processors also support better power efficiency versus
MPUs, which in turn helps reduce power consumption and operational costs over
large industrial installations.
3D Printers—Greater precision with fewer parts
A typical 3D printer requires four different MCUs—three for the various
motors that control the X-, Y- and Z-axis print heads, plus an additional for
the 3D printing extruder. But our i.MX RT replaces those multiple chips with a
single, integrated processor with 4x FlexPWM to address all the necessary
motors in a 3D printer. This dramatic reduction in key components not only
simplifies designs, it also reduces materials costs, while higher performance
control algorithms can be adopted.
The i.MX RT’s
multi-motor control peripherals design also makes it easier
to synchronize the multiple motors for greater printer precision. The i.MX RT
uses an advanced motor control algorithm (micro-stepping) with a
high-performance CPU and peripherals to further improve system performance.
Other integrated features that directly apply to next-generation 3D printer
designs include support for advanced graphics, multimedia and HMI for easy
programming, this makes it possible to only use one i.MX RT chip for 3D
printer system including the main controller and motor controllers.
Drones—Lighter designs with longer flying times
Another example of how the i.MX RT Crossover processor offers an exceptional
motor control solution is in Unmanned Aerial Vehicles (UAVs)—known more
commonly as drones. The i.MX RT features four high-speed, sensorless, field
oriented control (FOC) electronic speed controllers (ESCs) for motor control
within drone designs. Combining the flight controller and ESC within single
chip enables more simplified designs—lighter and cheaper builds—without sacrificing processing performance (600MHz).
They also include highly integrated
wireless connectivity (Wi-Fi®, Bluetooth®, BLE,
ZigBee® and Thread™) for maintaining reliable remote control
functions for operators.
In addition, i.MX RT solutions provide
low dynamic power consumption through features such as a
fully integrated PMIC with a DC-DC converter and efficient power gating. These
features can effectively help double the battery life for
drones and other portable designs.
As an industry leader with a proven history in motor control solutions, we
feel the i.MX RT offers something that no other product on the market can
touch in terms of the features, performance, usability and flexibility it
presents in a single chip.