Your motor control designs just got a whole lot smarter with one little chip

Your motor control designs just got a whole lot smarter with one little chip

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 processing level.

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 sycn 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 Channels
  • 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 (drones)
  • 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 extruder)
  • 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.

Jintao Zeng
Jintao Zeng
Jintao Zeng is a senior product manager at NXP Semiconductors. He has more than 20 years of experience in the semiconductor industry, spanning circuit design, business development, technical marketing and product management. Jintao holds a BSEE degree from Shanghai Jiao Tong University, MSEE degree from Purdue University at West Lafayette and an MBA from the University of Texas at Austin.

Comments are closed.

Buy now