4 ms·
An interesting improvement over naive operation I thought long ago: idle elevators should go to 1/2 maximum floor! You easily cut average wait times in 1/2! Pr
by gnramires 5y ago
An interesting improvement over naive operation I thought long ago: idle elevators should go to 1/2 maximum floor! You easily cut average wait times in 1/2!
Problem is, it's also energy inefficient. If you get a passenger at floor 1 or 0, you've wasted a lot of movement. On-demand movement wastes minimally.
So I've learned of a tradeoff between energy and waiting time -- not just elevator speed, but in algorithms.
It's fun to consider a minimal energy solution (it takes a very long time to get anywhere ;) ).
- gnramires 5y agoI've also learned it's a classic under-specified problem. To solve it completely you need, for example: 1) distribution of arrival times and destinations of passengers; (For example, if late evening people usually go up, it's best to idle on ground floor) 2) a "satisfaction function", giving a measure of performance of your system: You can get low average waiting times and diverging maximum wait time for a busy elevator, simply trade time from a single passenger for others (by e.g. never going to a floor). As long as utilization is significant at all times, this phenomenon exists. Clearly it's not only average we care about, but also maximum and minima of transit times. --- It's a very illuminating modelling exercise.