Hi everyone!
I'm working on a morphing robot that can operate both as a drone and as a wheeled ground robot, inspired by the ATMO project: https://github.com/mandralis/ATMO.
The robot will fly to a building, land, and then navigate autonomously on the ground using ROS 2. I'm currently designing the four-wheel ground locomotion system.
The estimated total robot weight is around 5–11 kg, but weight is a critical factor because the robot must also fly. Any additional motors, gearboxes, transmissions, and supporting structures affect the overall flight weight and potentially the flight time.
The ground environment will mainly be smooth indoor ceramic floors, such as university hallways. The robot should perform accurate 90° and 180° turns, including in-place turns when necessary.
I'm considering two drivetrain configurations:
Option 1: Four motors
- One geared DC motor per wheel.
- Four wheel encoders.
- Independent wheel-speed control using PID.
Option 2: Two motors
- One motor drives both wheels on the left side.
- One motor drives both wheels on the right side.
- Mechanical power transmission to the second wheel on each side using gears, belts, or another lightweight mechanism.
The chassis and some drivetrain components will be 3D-printed.
My main goal is to find a good balance between minimum weight, mechanical simplicity, energy efficiency, and reliable ground odometry.
I'd appreciate advice on the following:
- For a flying-ground morphing robot, would you recommend two motors driving four wheels or four independent wheel motors? How significant is the weight difference in practice?
- Would four independent wheel encoders meaningfully improve odometry accuracy, or would lateral wheel slip in a four-wheel skid-steer configuration dominate the error?
- How significant is wheel scrub during in-place turns on smooth ceramic floors, and how can it be minimized?
- What lightweight wheel and transmission options would you recommend for a 5–11 kg robot that must also fly?
- Would a belt transmission, gears, or another mechanism be a good choice for driving two wheels from one motor?
- What is the best practical approach to calibrating skid-steer odometry using wheel encoders and an IMU in ROS 2?
- Are there any papers, open-source projects, or real-world examples of morphing aerial-ground robots that I should study?
I'm particularly interested in practical experience with lightweight mechanisms and the trade-offs between drivetrain weight, ground mobility, and flight performance.
Thanks!