It works!!!! I can only conclude that I botched the previous version, producing something that compiled, but somehow skipped over vital code or processed it in the wrong order.
Web server refreshed at 2x per second and it still drives smoothly around obstacles without stopping or apparent hesitation. 3 ping sensors produce a decision approx 12x a second. This is a great starting point.
I can overwhelm it with 2 clients seeking data. It starts losing ping readings for some reason. I can correct that by slowing the refresh rate to 1x per second.
How do I post longer code than 9500 characters?