Pick up Mechanism

The system to be used in picking the balls up off the court consists of a single rotating shaft mounted on the front of the robot with 4 or 5 rows of stiff, plastic bristles that shall push balls up a curved ramp and into an onboard storage bin area in the chassis. The storage area is designed such that the bottom plate of the bin can be raised by use of a motorized pulley system to unload balls over top of the bristle wheel. The bristle wheel is in constant rotation when the solution is in operation. The figure below describes various details of the system in collection mode.

The build consists of aluminum frame that shall be tack welded and riveted to the existing Kodiak chassis. The side panels consists of the support framework for the system components, and make use of the existing mounting holes in the Kodiak chassis body. The rotary wheel is to be chain driven from a spur gear that is pre-mounted on the Kodiak chassis. All measurements for the existing Kodiak structure are available in the Kodiak database provided by the UW Robotics Team. Further torque analysis shall be done to determine the minimum required torque to rotate the bristle wheel and lift the maximum amount possible load (geometrics allows for a maximum of 4 balls to be lifted in any given 90 degree rotation of the bristle wheel).

A force analysis will be required to determine the optimal height of the pulley rod, and the motor torque required to lift the bin platform from a horizontal position to nearly vertical position, while considering the weight of the platform and ball load. The motor for the pulley system is to be mounted underneath the storage bin platform in front of the drive wheel motors (not viewable in the diagrams). The pulley support links are to made adjustable to accommodate some adjustability. The system gives unloaded balls a potential energy of 0.109 N at a height of 18.5 cm from ground level. This should allow enough feasible potential energy to displace the balls to a desired orientation in the drop-off bay to reload into the ball machine.

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