Add two cost parameters for each vehicle type

[tcokyasar44]

Just to increase the complexity, how about adding two different cost parameters for the same vehicle type? For example, a hybrid vehicle runs the first x distance/time on EV-mode, and hence the cost is lower than the distance/time after x. Meanwhile, another vehicle type with a fixed cost can be a benchmark. Is it possible to model this?

[orwant]

I really don't think you want to go there :-) Instead, choose a lower overall operating cost for the hybrid. That keeps the modeling easy, and it also better reflects reality: your typical hybrid car experience is not "electric for these 5 miles, then gas for the next 5" but a blend as the car turns the engine off and on all the time (speaking as a former Prius owner). Similarly for planes, which burn fuel at different rates depending on altitude and speed: you *could* attempt to model that, and even make those decision variables, but you'd be upping the complexity of your problem so much that it changes how you'd solve it. Jon

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On Sat, May 15, 2021 at 7:27 AM tcokyasar44 ***@***.***> wrote: Just to increase the complexity, how about adding two different cost parameters for the same vehicle type? For example, a hybrid vehicle runs the first x distance/time on EV-mode, and hence the cost is lower than the distance/time after x. Meanwhile, another vehicle type with a fixed cost can be a benchmark. Is it possible to model this? — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#2545>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACFCEWZKM5LYSSJ3QU4MYFTTNZLA7ANCNFSM445ZQKQQ> .

[tcokyasar44]

Hey Jon,

I admit that introducing even more complexity to a readily NP-hard problem is not ideal. Can I at least model the problem for two types of vehicles where the first set of vehicle charges c_1 cost per time unit and the second set charges c_2 cost?

[paultrow]

You can define a separate cost function for each vehicle using SetArcCostEvaluatorOfVehicle (https://github.com/google/or-tools/blob/v8.1/ortools/constraint_solver/routing.h#L898). You need to create a separate callback for each vehicle, which returns the travel costs for that vehicle, and pass the callbacks to RegisterTransitCallback - see https://developers.google.com/optimization/routing/tsp#dist_callback1.