3. Wiper Prototype

Prototype Features

• The prototype has 4 components: the gear train, two single-crank 4-bars, and one 5-bar.

• The gear train transmits motion from the motor. The idler gear speeds up the motion by a factor of 1.67 (5/3). This creates asynchronous motion between the two 4-bars, with one 4-bar crank completing 3 rotations in the time it takes the other to complete 5.

• The 4-bar output links are then used as part of a 5 bar, which has 2 DoF and therefore can combine the outputs of the two 4-bars.

• The final output is a complex pattern combining CW ellipses, CCW ellipses, and back-and-forth motion.

• Any of the link lengths can be changed and any change affects the output motion pattern. I will use a MATLAB simulation to test various configurations and plot their output motion patterns.

Figure 5. Physical Prototype