Context

The final project of Introduction to Engineering and Design (Pengantar Rekayasa dan Desain), a course that takes a team through the whole design process, from a need to a built and tested prototype.

Problem

Build a solar-powered car that travels a set distance and stops exactly there. This requires a braking mechanism that triggers at that point.

Approach

• Power: the car runs on a battery, which is charged by solar cells before the run.
• Stopping mechanism: during the run, the solar cell works as a sensor. A container of water sits on top of it, and ink drips in as the car drives. The water darkens, less light reaches the cell, and once the liquid is dense enough the cell stops producing voltage. That drop in voltage is the signal that stops the car.
• Distance tuning: the stopping distance is set by the amount of ink added to the water.
• Control: an Arduino Uno, with relays for switching.
• Chassis: a four-wheel car, modeled in SolidWorks (see the gallery).

My Contribution

• Electrical: wired the car’s electronics.
• Programming: wrote the Arduino program.

Result

The car stopped close to the target distance. The exact accuracy was not recorded, but the stops were not far off.