CBC Initial Design Concept:
· A plow at the front of the CBC would catch the water balls as the CBC ran forward. This initial concept was supposed to obtain the 30 points for the water ball.
· The CBC’s plow would catch the water balls as it ran forward. The forward motion would push the water balls further into the plow’s funnel and secure them inside the cavity. The plow was refined so that it could fit up to four water balls instead of only one as it was capable of earlier.
· A peculiar feature of the plow is that it was very large. The team plans to be able to catch all the water balls on one trip so the plow was enlarged to fit four balls with no difficulty. The shape of the plow was also more like a square rather than a triangular funnel so that the cavity inside was more abundant with space for the water balls. Also, the plow is extremely light. The walls of the plow are thin and low. The water balls are secured inside the cavity because four bendable plastic tubing attached to each side of the plow function as walls.
· The most difficult aspect of implementing this concept is ensuring that the CBC continues to run forward continuously when the water balls are secured inside the plow because if the CBC stops or runs backwards, the water balls will roll out of the plow, since the plow has no gate.
· We will certainly use this plow for the CBC because we have already tested it and it has proven to be very reliable. It is simple and sturdy and the plow does not require a servo to function, which eliminates the likelihood of programming errors.
Roomba Initial Design Concept:
· A compression mechanism constructed from metal rods will be used to capture and secure bot guy off his pedestal to obtain the x3 points.
· The compression mechanism functions by having a long metal rod that is attached to a servo, spin and slam into bot guy off from his pedestal and against another long metal rod that does not move. Bot guy will be secure because the long metal rod attached to the servo will push him against another metal rod and he will remain compressed between these two metal rods.
· A key feature in this design is that it does not need another cavity space on the roomba to drop bot guy in once bot guy is captured. The compression mechanism acts as a way of securing bot guy as well as catching him. Another notable feature is that although the compression mechanism resembles a large, simple claw, only one side of the compression mechanism actually moves. The other side of the mechanism does not need to move. It merely functions as an obstacle that bot guy is pushed into by the movable rod on the other side.
· The difficult aspect of implementing this mechanism is programming the roomba to activate the compression mechanism once it is only very close to bot guy. If the roomba is close to bot guy, the compression mechanism might not work because the compression mechanism only swings into bot guy with enough force only if bot guy is very close to where the two metal rods intersect.
· We will definitely use this design. We have successfully programmed the roomba to activate the compression mechanism once it is within acceptable range of bot guy. It is much more reliable than a claw and it does not require another cavity space to put bot guy in once he is captured.
Roomba Rejected Design Concept:
· A possible arm with a claw to grab bot guy was rejected. An extendable arm with a claw at the end would be a possible mechanism for grabbing bot guy off the top of his pedestal. This rejected concept was supposed to be used to transport botguy to the peak in order to obtain the botguy x3 points.
· The robot would score these points by using a sturdy claw that would open and then close and clamp bot guy when the arm of the claw straightened like a scissor lift.
· The robot would have a claw made out of legos. It was constructed out of several long plastic pieces that were kept together by axels when they overcrossed each other. They formed an arm that extended just like a scissor lift. The end of the scissor lift arm, which was the actual claw, was comprised of four bent-L shaped plastic beams. Each side of the claw has two of these L-shaped pieces. When the arm of the claw straightened, the claw would close and be able to secure bot guy. One side of the end of the arm opposite from the claw would be attached to a servo. When the servo spun 60 degrees, it would also shift the end of one side of the arm 60 degrees. The other side of the arm would shift 60 degrees the opposite direction because of the presence of the numerous axels. Depending on what direction the servo spun, the scissor lift like arm would either compress and widen to open up the claw at the other end, or the scissor lift like arm would become straighter and longer to close the claw at the other end in order to grab bot guy.
· This idea was difficult to implement for the fact that approaching bot guy at a high speed while he is unstably placed on the platform risks knocking him over. Also if the claw was larger, then it was difficult to close the claw entirely, thus creating the risk of dropping bot guy out of grasp. If the claw was smaller, then it was difficult to actually grab bot guy.
· This idea was rejected because the scissor lift claw was too clumsy and it was challenging difficult not to drop bot guy. It was discovered that the compression mechanism to secure bot guy was simpler and sturdier.