Suggestion… Offer the Rover a dog biscuit – Test Video #7
Yesterday evening we couldn’t get the rover into a successful turn. I went home and thought about the issue but after posting it this morning my friend Allen had a suggestion.
“Have you tried a biscuit treat? It works for my dogs real well.”
Sadly, the dog biscuit didn’t elicit a response the response I was hoping for. 
My suspicion was that we weren’t getting enough torque to overcome the lateral friction on the tires. At 50% power (duty cycle), the pulse we were sending just weren’t big enough. This morning we cranked the duty cycle up to 99% and this is what we got.
Here is what we tried:
- Turning Test 1: Duty Cycle = 50% –> shivering sad puppy behavior
- Turning Test 2: Duty Cycle = 50% with additional weight on the rover –> shivering sad puppy behavior
- Turning Test 3: Duty Cycle = 99% –> Successful turn
- Turning Test 4: Duty Cycle = 95% –> Successful turn
- Turning Test 5: Duty Cycle = 90% –> Successful turn (slow)
- Turning Test 6: Duty Cycle = 80% –> Failure (partial turn and stop)
- Turning Test 7: Duty Cycle = 85% –> Failure (partial turn and stop)
Success
That tells us that when we want to execute stationary turns we should probably kick the duty cycle up to 90% or higher. Now that we have good turning behavior we can move on to quantifying the turns. We want to be able to spin the device with some degree of precision.
