2- Initial Concepts and Prototypes

Moving an Oreo cookie from its container, dipping it into milk, and bringing it to the feeding position is fundamentally a position and velocity problem. To solve this we would need to create a linkage that picks up the cookie, rotates 90 degrees, dips the cookie, and then rotates 90 degrees to feed the operator. This must be done slowly enough not to lose the cookie during this process. The challenge in designing the linkage came from obtaining the three stops.

Figure 4: Three Stages of Operation

One of the challenges we faced when designing our pick and place mechanism was how to achieve a vertical profile for the picking stage. Our initial ideas all involved motion profiles that followed a parabolic profile downward, which would not work for our desired motion because this type of profile would knock the glass over in the dipping stage. We also knew we wanted some way to actuate the end effector to a position where the cookie would be easy for the consumer to get. The utilization of MotionGen played a crucial role in the iteration of the design to achieve the desired motion profile. By adding links and adjusting link lengths, we were able to see how these adjustments would affect the motion profile of the end effector. 

Figure 5: Iterations of mechanism design through MotionGen

MotionGen proved to be a really helpful tool as we were able to visualize how increasing the length of the top two grounded links would change the amount that the end effector would rotate in the serving position. Additonally, we were able to see how changing the bottom right grounded link affected the vertical motion that we desired.

Figure 6: Linkage Design in MotionGen - Dipping Position

Figure 7: Linkage Design in MotionGen - Serving Position

Figure 8: Linkage Design in Solidworks - Dipping Position

Figure 9: Linkage Design in Solidworks - Serving Position

Figure 10: Pick and Place Mechanism in Motion

Figure 11: First Iteration of Prototype

Figure 12: Second Iteration of Prototype