A normal 4 bar allows an end effector to always stay parallel to the ground by using parallelogram-structured bars. A virtual 4 bar allows the same functionality while taking up much less space by utilizing belts. Keeping the intake parallel to the ground was 35% slower during auto than Tele-Op. To address this, our uniquely geared virtual 4 bar uses different size pulleys on our belts to allow the intake to move from the ideal transferring position to the ideal intaking position, while keeping the same efficient packaging. It also means that instead of having an additional pitch servo on the end, we only need 1 servo, which helps reduce power draw. We found the optimal intaking angle to be ≈ 135° from horizontal and used that to calculate the correct number of teeth for our pulleys.
To calculate the pulley ratio for the belt we used this equation. 135 deg indicating the arm rotation and 60 deg indicating target end-effector rotation.
