Multistage Tray Shifter Counterweight Vibration Control

The patent applies the counterweight principle by assigning opposite movement directions to trays based on their stack numbers. When multiple trays are moved simultaneously to their home positions, trays with odd stack numbers move in one direction while trays with even stack numbers move in the opposite direction. This causes the forces generated by the trays to counterbalance each other, significantly reducing the net vibration and noise during initial operation while maintaining efficient positioning.

The patent applies local quality by making the movement direction property dependent on the local characteristic of each tray (its stack number). The control system determines the movement direction based on whether the tray's stack number is odd or even, allowing each tray to have a customized movement pattern tailored to its position. This simple rule-based approach minimizes control complexity while achieving the vibration reduction goal.

By moving trays in opposite directions based on their stack numbers, the patent creates counterbalancing forces that reduce the net mechanical stress on the system during simultaneous initial operation. The opposing movements cancel out the cumulative load that would otherwise be placed on the mechanical components, allowing fast initialization without excessive stress.