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Introduction

As any cat owner knows, cat litter inevitably tracks throughout the home, regardless of the type of litter used. Despite even owning brands that advertise 'non-tracking' litter, there is always some litter that always makes its way out when the cat exits the litter box. Instead of sweeping up every time when my cat uses the litter box, I decided to automate it with a Raspberry Pi, a couple of cameras, and a Roomba. This page outlines the modifications and design of my automated cleaning system. To see it in action and understand how it works, click here.

Why a Modifed Roomba?

There were a couple of reasons why I wanted to modify a Roomba specifically:

1. Roomba's Open Interface - iRobot has an open interface that allows control over the entire Roomba and access to all of its sensors. This feature coupled with the ROS 2 Driver (create_robot) from AutonomyLab allows me to only look at integrating the high-level action and logic into the system. This setup streamlines the process, allowing for a more efficient development of sophisticated functionalities without the need to manage the underlying hardware interactions directly.
2. Low Cost - Given that the Roomba 694 has been on the market since 2020, I was able to acquire one for under $60. Designing and building a similar system from scratch for cleaning litter would have required many hours and it likely would have cost over $100 in parts alone. Opting for the Roomba 694 offered a cost-effective and time-efficient solution.

Design Changes

For my project, I set up the Roomba to vacuum specifically around the litter box area and avoid small obstacles in its path. I used a security camera/baby monitor with a real-time streaming protocol (RTSP) integrated to oversee the area, track the Roomba, and track state changes with the litter box. An AprilTag was attached to the Roomba, allowing the security camera to track and localize the robot effectively. This system helps the Roomba navigate and stay within the defined cleaning path, ensuring targeted cleaning around the litter box.

Note: Privacy with cameras in a home is a concern. The placement of the security camera in my apartment was carefully chosen to maximize privacy for anyone present. It is positioned to capture only from the waist down in 90% of the frame. This arrangement ensures that while a large surface area is monitored for litter tracking, personal privacy is preserved. Similarly, the camera installed on the Roomba is angled with a 10-degree tilt toward the floor. This specific orientation is designed to focus solely on object avoidance near the Roomba, ensuring it functions effectively without compromising privacy or intruding into personal spaces.

Ultimately, these are the components I integrated into Roomba.

1. Raspberry Pi Zero 2W - Runs ROS 2 Humble and runs the create_robot package and camera node.
2. Raspberry Pi Camera 2 - Used for obtaining sensing small obstacles the bump sensor cannot detect.
3. April Tag - Used for localizing the robot in the litter box space.
4. Lifted Enclosure - Allows access to the regular Roomba buttons for reprogramming.

Key Takeaways from this Project

• Use Docker instead of the Zero 2W to build all the packages. Otherwise, it won't compile because while a Raspberry Pi Zero 2W is efficient, it's not that powerful and limited on RAM. Use a ROS 2 ARM-based Image and emulate the ARM architecture if you use an x86 computer.

Projects with Cypress

Cat Tracking and Litter Containment - Automating and keeping my home litter free.

Link Here

Video Game Vacuuming - Vacuuming made fun using a PS5 controller.

VIDEO HERE

Bill of Materials