Week 5

Overall Progress

Accomplishments

Mechanical:

• The Drive train was designed, 3D printed and assembled. The motors previously ordered doesn't have enough torque to turn under the weight of the robot. So new stronger motors have been ordered. But the drive train operates well when unweighted with wheels lifted off the ground.
• The catapult arm was assembled and mounted onto the robot.
• Incorporation of elastic bands instead of a spring. After multiple tests it was found that the desired trajectory required something that was strong (didn't deform easily) but stretchy enough to be tension-ed easily and provides the elastic potential energy necessary.
• The reset mechanism for pulling back the catapult was designed and 3D printed.
• The bean bag mechanism was designed and assembled.
• Latching mechanism design in progress

Electrical:

• Electrical board placed mounted onto robot base on front half.
• Most electrical components mounted to the board.
• Started on path planning and trajectory following.

Software:

• Most of the work this week was done mechanically and electrically. Some progress has been made for integration of software components with the rest of the robot.

Challenges

Mechanical:

• The initial driving mechanism that focused the load entirely on the motor shafts weren't stable enough. So the new drive train was designed where the load is on the bolt going through a hole in the extrusion. The redesign, CAD and 3D printing and assembly was accomplished overnight.
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Electrical:

• Electrical board reduced in size and more components added.
• Still need a few components to fully assemble electrical board.

Software:

• Getting some kind of path planning algorithm which will recompute the path if some obstacle appears. So far we have obstacle leading to a stop but that is a placeholder

Plan for week 6

• Mechanical:
  • Replace current catapult shaft with one that has a larger diameter. It will make the throwing system more robust.
  • Finish design and assembly of the latching mechanism.
  • Redesign motor mounts for the newer motors
  • Complete integration of all the systems onto the robot frame.

Electrical:

• Make. It. MOVE.

Software:

• Integration with more parts
• Making the sensors detect timing and position from multiple ultrasonic sensors to find a position, then using that position over time for obstacles, estimate a linear path as a function of time x(t). Then, using our robot speed, plan a path such that their path x(t) does not collide with our path y(t) when t is equivalent.
  • Essentially, find non-intersecting functions x(t) and y(t) in 3-D space where x(t) is a predicted path from our sensors and y(t) is our objective path given a starting point (current position) and ending point (goal).