Allocating destination calls using genetic algorithm employing chromosomes

Method for handling destination calls in an elevator group comprising several elevators using destination call control, which method comprises an allocation procedure for situations where the calls can't be served by all elevators of the elevator group in one round trip, in which situation “n” open calls and “m” fixed calls are present, which fixed calls are already allocated but not served, in which allocation procedure comprises:

• a) forming chromosomes comprising genes in which chromosomest,
• n first genes comprise a correlation of each open call and a corresponding elevator,
• n second genes comprise a correlation of each open call and the corresponding number of the round trip in which the open call will be served, and
• m third genes comprise a correlation of each fixed call and the corresponding number of the round trip in which the fixed call will be served,
• b) calculating for each chromosome round trips for each elevator of the elevator group according to collective control,
• c) evaluating the round trips of all elevators calculated in step b) according to known optimization criteria,
• d) presenting chromosomes evaluated in step c) as sufficient to the forming of a new generation by per se known genetic algorithm (“GA”) methods,
• e) repeating the steps b) to d) for each chromosome of each new generation of chromosomes until a stop criterion is achieved,
• f) wherein the calls are served in collective control according to the best chromosome of the last generation, and
• g) assigning the destinations of each elevator in its travelling direction in the current round trip according to the best chromosome to allow them to be shown on at least one common display shortly before each elevator's arrival at said landing.