Biweekly Updates

This week we assigned to each member of the team their specific area of technical analysis. Sahil set up mcbd-40.monday.com to keep track of progress for each member. 

Current assignments are as follows:

• Technical Analysis

  • Electrical (Chris) 

    • Ctrl System 

    • Electronics

  • Structural (Christian, Ryan, Gunnar)

    • Kinematics (Velocity, Acceleration)

    • Settle on concept we want to go for

  • Ferrofluid (Christian, Sahil)

    • Material Properties

    • Calculations (quantity and force)

More design and redesigns are done to the omniwheel component of the ball drive. We will be using a basketball as the new tire mechanism which would help us ease the grip design. We will still be using ferrofluid to develop the magnetic coupling mechanism. 

Breaking down last year's MCBD robot to reuse the parts for this year. We intend to recycle and reuse parts as it helps us remain cost effective and allocate monetary resources to other parts of development. 

We will be reusing the motor components, such as the motor controllers, motor drives, Arduinos, and even the cables. 

Any fabricated components, like 3d printed designs, will be made new from scratch. 

The updated MCBD design is focused on reducing the overall footprint by resizing the chassis and suspension system. The chassis now features reinforced joints for added stability and accommodates new vertical bars.

 Additionally, the ball drive is being updated with new omni wheels, and motor mounts are being adjusted to shrink the system's footprint. CAD parts will be reused where possible, with new motor mounts designed for the updated specifications.

The MCBD is designed as the mobility unit for the ARGOS system, forming a mobile remote presence (MRP) robot. The visual shown is an approximate representation of how the MCBD integrates with ARGOS to provide the mobility capabilities needed for the MRP. The MCBD enables smooth movement and adaptability, facilitating remote presence and interaction.

The control system for the MCBD has been successfully developed to manage the movement of a single leg. The leg is independently controlled using a set of motors, and the system is capable of precise control over both forward/backward and side-to-side movements. By implementing this control system on one leg, the base functionality is established and can be scaled to all three legs for full mobility.

For further testing and refinement of the system, the control logic for one leg was thoroughly tested, ensuring that the movement and response to joystick inputs were accurate and responsive. The initial testing involved mapping the throttle and steering values to motor speeds, and the system was calibrated to ensure smooth motion. This was followed by analyzing how each leg behaves independently to refine the individual motor control.

These two weeks were spent learning to print and mold the rubber material that is used to make the ball for the ball drive. The main goal was figuring out what material we can use to create the molds so that we can easily take out the formed mold. The final mold would likely be reusable, easy to release the formed mold, and easy to print on the 3D printer. 

To scale the control system for three legs, each leg must move in unison by adjusting the motor speeds for the X and Y axes (side-to-side and forward-backward). The control logic involves calculating each leg's movement based on joystick input, ensuring that all legs move together. Rotation is handled by adjusting motor speeds in opposite directions, depending on whether the system needs to turn clockwise or counterclockwise. 

The kill switch feature ensures safety by stopping all movement if triggered. The motor control system combines these movements, ensuring all three legs work in harmony for smooth operation and rotational control.

Throughout these two weeks, the old team's ball drive was deconstructed to determine what we can reuse for the 4.0 iteration. Additionally, we began to finalize the design for the omniwheels. We have opted to try and design an omniwheel that has overlapping components. That way we can optimize surface area contact between the omniwheel and the ball drive components. 

During these two weeks, we have finalized molding of the balls for the ball drive component as well as the design for the frame of the MCBD. We have opted to use a durable, shape keeping, yet flexible plastic material for the internal of the ball drive. On the outside is the magnetic mixture that is poured into the mold and rests on top of the internal core. Additionally, we are finalizing the control system logic for the ball drive and the motors. Currently, the main goal is to synchronize the ball drive motors based on the diagram created in the weeks of 3/16.