Idea 1: Foosball goalie
I’d like to integrate the areas of the class into constructing an automatic foosball goalie.
There are two design possibilities:
- A system that is placed onto the foosball table itself, with its own bar and goalie.
- A system that controls the existing goalie rod by attaching to the handle.
I think #1 would be more feasible and reliable, though less integrated. It has the benefit that it could play in a self-contained setting (e.g. on a tabletop).
There are two critical problems or design thresholds I see:
- Actuator speed: can I move the goalie quickly enough to do anything useful? This will require exploration of high-speed servos or other gearing schemes.
- Sensor speed and accuracy: can I reliably determine the ball’s location and trajectory?
For the actuator, I’m basing my thinking off of inkjet printer heads. I imagine a belt-driven system that can achieve quick horizontal motion.
For the sensor, I’m debating between an IR sensor bank on/around the goalie figure and ultrasonic sensor(s) aiming towards the middle of the field from the outside edges. I will need to research the timing and accuracy of these possibilies.
Idea 2: Bicycle power meter
A more recent idea is tracking power output on a bicycle (wattage). Several commercial solutions exist, but they are cost-prohibitive for the tinkering hobbyist. Can I make a workable solution from a cost-effective kit of parts?
- Force sensor at the pedal. This would measure the force exerted by each foot. Do resistive strain gauges have enough dynamic range? Could I mount it in a pedal or in the shoe/pedal interface?
- Accelerometer at the pedal, crank, or shoe. The crank position is key for determining the work of each pedal push. Will cheap solid-state accelerometers work for this?
- Wireless transmitter with sensors. The sensors rotate and move in complex ways, making wired connections to a base station impractical or impossible. They will have to interface to the user display with a wireless link.
- User display. This would analyze the sensor input and produce (and record) measurements. UI and connection to a computer for analysis are key.