Robotic vacuums have surged in popularity over the past decade, thanks to their ability to keep homes clean without
the
hassle of manual vacuuming. These robots utilize spatial computing algorithms for navigation, broadly referred to as
SLAM, an abbreviation for simultaneous localization and mapping. Traditionally SLAM is processed on powerful
embedded
processors. However, the introduction of NXP’s crossover microcontroller units (MCUs) signals a new breed of these
devices that deliver the real-time performance, power efficiency and connectivity required to navigate and clean
residential and commercial spaces more efficiently.
Since 2011, bObsweep has
developed a range of intelligent floor-cleaning robots that help keep homes spick and span.
Its
product portfolio includes several models that target a variety of needs and price points (for example, PetHair,
Dustin and
Ultra-Vision).
bObsweep's PetHair-based models are designed for homes with pets. They use a combination of sweeping, vacuuming and
mopping to remove dust and debris from various floor types. Building on the PetHair model, the upgraded Dustin adds
features like self-emptying, Wi-Fi connectivity, smartphone app control and a larger battery for extended-cleaning
sessions. bObsweep’s flagship robotic vacuum, the Ultra-Vision, takes cleaning to new fronts with the industry’s
largest
dust collector, an onboard camera and real-time computer vision processing for advanced low-height item detection
and
obstacle avoidance. Exceptionally agile, bObsweep’s Dustin and Ultra-Vision models boot in just 6 seconds, map on
the
fly
without the need for training runs, identify the floor layout at first glance and react to the environment at very
high
speed.
bObsweep vacuum at work in a modern home. Image credit: bObsweep
How Crossover MCUs Can Benefit Robotic Vacuum Applications
Historically, robot vacuums have relied on hefty CPUs in addition to one or multiple discrete MCUs to handle
processing
workloads, increasing cost, complexity and power consumption. However, a new class of processors known as
“crossover
MCUs” can support robot vacuums by combining the high performance and integration of application-specific chips with
the
real-time capabilities and ease-of-use of conventional MCUs. bObsweep is leveraging this innovation to consolidate
multiple vacuum functionalities into a single-chip solution (NXP’s i.MX RT1052 crossover MCU). This serves as the
vacuum’s cost-effective, yet highly accurate, brain.
Ordinarily, the various functions in a robot vacuum have been achieved by employing multiple dedicated processors. A
typical architecture comprises separate MCUs for low-level motor and sensor control, high-level compute CPU for
navigation, discrete wireless radio chips and more. However, spreading workloads across multiple chips increases
the
cost, complexity and points of failure. Multichip systems also consume more PCB real estate, limiting design
flexibility.
To deliver a superior user experience and the best value to their customers, bObsweep took a different approach to
designing its products’ hardware and software.
Elevate your applications with advanced processing and efficiency. Learn more about how the
powerful
i.MX RT1052 crossover MCU.
The “Right Chip” for the Job
Block diagram of the i.MX RT1050 crossover MCU. Image credit: NXP
The i.MX RT1052 is part of NXP's crossover MCU series combining the high performance and integration of application
processors with real-time capabilities and ease-of-use of conventional MCUs. This MCU contains an Arm® Cortex ®-M7
running at up to 600 MHz, providing ample computing power to handle low-level real-time tasks, such as motor
control,
sensor fusion and navigation planning. NXP’s i.MX RT1050 crossover MCUs also provide a CSI interface, which is used
to control
the
CMOS sensor, and up to 1 MB of tightly coupled memory to allow the entire processing to be contained onboard.
i.MX RT1050 crossover MCU. Image credit: NXP
Connectivity and Interfacing
Robotic vacuums use a variety of interfaces to connect sensors, actuators, wireless modules and other peripherals.
The
i.MX RT1052 handles all of these with an extensive set of integrated I/O options, including:
- Multiple I2C, SPI and UART ports for sensor interfacing
- Up to 12 PWM channels for brushless DC motor control, audio and display interfaces
- USB/CAN connectivity for external modules
Advanced Graphics and Computer Vision
The Ultra-Vision is bObsweep's most sophisticated and intelligent robotic vacuum to date, setting a new standard for
cleaning performance and obstacle avoidance. However, even with advanced features like visual object detection, the
Ultra-Vision still only requires a single i.MX RT1052 chip to handle all processing tasks. The i.MX RT1052 enables
the
Ultra-Vision to see and react to obstacles faster than any other robotic vacuum on the market while still
maintaining
a
compact, cost-effective processor architecture. This is the secret sauce behind bObsweep’s highly affordable prices
for
very high-end products.
A parallel 8-/16-bit camera interface allows direct connection to raw Bayer image sensors at up to 720p resolution
and
60 fps. The i.MX RT1050 crossover MCUs integrated Pixel Processing Pipeline (PXP) hardware offloads image
preprocessing tasks,
including color space conversion, scaling, alpha blending and rotation. The PXP can manipulate images on the fly
without CPU intervention.
Combining a camera interface and PXP allows bObsweep to integrate computer vision into its vacuums cost-effectively.
The
camera feed is processed instantly to detect and identify objects in the robot’s path without using an external
vision
processor or GPU.
Power Management and Efficiency
Battery-powered devices like robot vacuums demand the utmost efficiency to maximize runtime between charges. The i.MX
RT1052 excels in low-power applications.
The chip includes an integrated power management IC with a high-efficiency DC-DC converter that powers the MCU and
external components, reducing the need for external power management circuitry. Low-power modes allow the CPU clock
speed and core voltage to be throttled during periods of light load, and full deep sleep mode can achieve current
consumption as low as 4.6 mA while still maintaining SRAM content and GPIO state. The i.MX RT1052 MCU also provides
flexible clock gating for peripherals, allowing unused modules to be automatically shut off to eliminate leakage.
Development Platform
NXP has gone to great lengths to simplify the development of the i.MX RT with a comprehensive software and tools
ecosystem. Its MCUXpresso SDK includes project files for MCUXpress for VS code, MCUXpresso IDE, Keil MDK and IAR
Embedded Workbench. Support for FreeRTOS™ on the i.MX RT1050 crossover MCUs is also available.
In addition, the i.MX RT series is also supported by the Zephyr Project, offering developers a full-featured, widely
tested, secure RTOS with a flexible licensing model. Zephyr's modular architecture and robust device driver
infrastructure make it easy to tailor the OS to fit the specific needs of robotic vacuum applications.
Configuration tools for setting up pin muxing, clock trees and power sequences eliminate much of the work during
product development.
Sweeping the Competition
With NXP's i.MX
RT1050 crossover MCU as the foundation for its platform, bObsweep delivered a family of robotic
products
that provides high performance, efficiency and intelligent features. The i.MX RT1052 is an ideal “brain”
for
robotic vacuums, with its architecture offering high-speed control, real-time operation, advanced processing and
reliable connectivity.