University of Alberta RoboMaster Engineering Team
Hero Robot
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Creative Fields: Robotics, Design, Manufacturing, R&D
Completion Date: 2022
Skills: Brainstorming, SolidWorks modelling, design, DFX, BOM, manufacturing, multi-discipline collaboration
Background: This robot was designed for the University of Alberta RoboMaster Team to participate in RMNA competition. Based on the rules of the competition, the hero robot should be controlled by an operator and need to be able to move freely inside the arena and battle against enemy robots by shooing projectiles (42mm golf balls). There is a referee system to calculate the number of shots received by the robot through sensors and decide the remaining health point based on that. The projectiles are not meant to or able to damage the robots! There were three subteams (Mechanical, Electrical, and Computer Vision) working on this project. The mechanical team was responsible for the design, modelling, manufacturing, and troubleshooting of all mechanical parts of the robot.
Project Details:
There are several design challenges for the hero robot:
The golf balls from the container to the barrel using “pipelines” but the rough surface of the golf ball would cause high friction forces even when rolling
To reduce the friction, numerous designs of the pipeline have been tested using 3D-printed prototypes. The final solution was to add a line of mini bearings at each turning point, which significantly reduced the rolling friction
The shooting system is supposed to be lightweight and compact allowing for fast aiming and a wider pitching range but the large dimension of the golf balls becomes the obstacle
To compensate for the size and weight of the pipeline and golf balls inside, the pitch motor was moved closer to the Yaw axis by a unique mounting structure with screw copper pillars. Additionally, weight reduction has been done to all the major parts of the shooting system based on FEA simulation results.
Powering the Yaw axis. There is a slip ring that’s vertically connecting the shooting system and the chassis. This design allows the chassis to spin freely to reduce the chance of getting hit by projectiles when the shooting system is aiming at any direction. The slip ring requires an external motor to power the rotational movement.
A gear set was designed to deliver the power from the electric motor to the top end of the slip ring. The gear set was 3D printed and had been test-proofed to be reliable and efficient. Compared to a traditional belt-pully system, a 3D-printed gear set reduced the manufacturing time and cost while allowing for easier disassembly for later testing and shipping.
Final Product:
Contribution and Disclaimer:
My work is only limited to the mechanical part of the robot and does not include the control or CV coding.
My contribution:
Conceptualized shooting system design and offered solutions to challenges mentioned above
Detailed modelling for the shooting system
Manufactured all the parts for the shooing system at Elko Garage
Assembling and troubleshooting of the entire robot