@@ -136,9 +136,9 @@ To find the best possible setpoint we decided to use the PID values of Bagnall's
| 600 | Too high | Falls forwards |
| 550 | Too low | Falls backwards|
| 580 | Too high | Falls forwards, with short balance|
| 570 | Too low | Falls backwards, with less balance than upper |
| 575 | OK | Feels like most backwards|
| 578 | OK | Pretty good initial balance with no preferende fall-direction|
| 570 | Too low | Falls backwards, with less balance than for sp = 570 |
| 575 | OK | Seems to mostly be falling backwards|
| 578 | OK | Pretty good initial balance with no preferred fall-direction|
| 577 | OK | Maybe better - really hard to tell |
*Table 1: Observations for the effect of various setpoint values for the balancing robot*
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@@ -173,27 +173,9 @@ Using the grid search approach again, we first tried with 40 (robot falling forw
We changed the setpoint to 585 and tried values of p between 40 and 70. As before, 70 caused violent oscillations and instability. Both 55 and 40 seemed more stable. We decided to continue testing with a value of 40.
Additional observation: The robot seems to stop briefly once in a while. This seemed to happen more with p = 70 than with p = 40.
*TRYING SOMETHING NEW (inspired by the above approach)*
*** skriv om: TRYING SOMETHING NEW (inspired by the above approach)***
Strategy: Trying extreme values for each variable to understand the effect of changing it. Then trying empirically to find good parameter values by utilizing this knowledge.
p20, sp585, i4, d33:
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p40, sp585, i4, d33:
SE VIDEO
p10, sp585, i4, d33:
SE VIDEO
p50, sp585, i4, d33:
SE VIDEO
p30, sp585, i4, d33:
SE VIDEO
IDAS NOTER:
- perhaps it doesn't really make sense to compare these sets of values (perhaps we should dinstinguish more roughly - "not standing at all", "barely standing", "standing")
We decided to finish up the experiments (long) before having tried all possible combinations of parameters values, as it seemed pointless to go on when seeing no significant improvements to the robot's behaviour - continuing would not improve on our understanding of the effects of the different PID parameters further. However, the parameter search inspired by grid search did provide us with a more structured insight into the effects of the different parameters than had we just tried varying each parameter on a whim.
