[FEA] Support for EV charging via vehicle capacity #589
Description
Vehicle capacities in cuOpt VRP solver are currently tied to tasks, increasing or reducing capacity every time a vehicle visits a task location.
To track EV battery status of a vehicle as the vehicle travels during the day, a new capacity concept is proposed. This type of capacity needs to be linked to "edges" traversed as opposed to "nodes" where tasks will dictate how capacity is used.
An ideal solution would be to have a vehicle capacity defined (ie. starting EV charge level), which gets depleted based on distance traveled between tasks (using an applicable depletion factor). The vehicle then must return either to a depot or to one of the charging locations to recharge, and the service time at the charging location should be a function of charge level (eg. to top it off) at the time of charging.
Using estimated break times and specifying break windows and locations (ie. for charging stations) may not work because it is hard to estimate a break window due to dynamic nature of tasks assigned and distance traveled before a recharge (small number of high-service-time tasks visited may involve short travel distances and low depletion vs. large number of low-service-time tasks visited may involve large travel distances and high depletion).