Transport management control apparatus and method for unmanned vehicle system

A transport management control apparatus which controls the transport of a plurality of unmanned vehicles traveling along travel routes formed from a plurality of connecting routes which connect nodes constituting vehicle stopping positions, said transport management control apparatus comprising:

• first means which searches for an optimal travel route which connects a present node to a target node having minimum cost for each unmanned vehicle, by calculating costs of travel for possible transport intervals connecting said present node and said target node based on the positions of said nodes and the connections between said nodes, and based on the results, selects a travel interval having a specified moving direction by determining for each unmanned vehicle the travel intervals in which there are conflicts with the travel routes of other unmanned vehicles and totaling the costs of the conflicting intervals, then restricting the moving direction of the conflicting intervals of the unmanned vehicle having the highest cost to a specified direction, to determine the most appropriate travel routes having no conflicts by eliminating said conflicting intervals in the order of the costs of the conflicting intervals with respect to the unmanned vehicles;
• and
• second means which simulates the temporal movements of each unmanned vehicle based on the travel routes determined by said first means, and if any of the unmanned vehicles are in a state of deadlock in which it is unable to advance, resolves the deadlock problem of said unmanned vehicle by:
• adding a relief route to the travel route of said unmanned vehicle by moving another unmanned vehicle which has already completed its work to a node having the least cost for moving thereto,
• changing the sequence in which unmanned vehicles pass through nodes by selecting a reservation sequence of nodes, containing unmanned vehicles which are not in a standby state, based on the number of passes which other unmanned vehicles make through the nodes,
• offering a detour route by selecting an unmanned vehicle which is not in a standby state, prohibiting passage through a portion of the travel route of said unmanned vehicle, searching for a detour route to the next node in the travel route of said unmanned vehicle, and substituting the detour route as a new travel route for said unmanned vehicle to move to said next node, or
• offering a passing route for temporarily yielding the right of way to an unmanned vehicle which is encountering the deadlock problem by temporarily moving an unmanned vehicle which is not in a standby state to a node having the least cost for moving thereto.

A transport management control method for controlling the transport of a plurality of unmanned vehicles traveling over travel routes formed from a plurality of connecting routes which connect nodes constituting stopping positions, said transport management control method comprising the steps of:

• a. determining the optimal travel route of each of a plurality of the unmanned vehicles;
• b. finding in the plurality of optimal travel routes obtained in step a., opposite direction intervals comprising travel routes having mutually opposite directions;
• c. halting processing if opposite direction intervals are not present, and if opposite direction intervals are present, then calculating an integral cost for each unmanned vehicle by totaling the costs of the opposite direction intervals in the travel route of each unmanned vehicle;
• d. applying a specified direction to an opposite direction interval on the travel route of the unmanned vehicle having the highest integral cost, so that this interval has one direction;
• e. again determining the optimal travel routes of all unmanned vehicles, with the above-mentioned application of a specified direction to the travel routes;
• and
• f. determining by the repetition of steps b., c., d. and e. optimal travel routes having no conflict.

A transport management control method for controlling the transport of a plurality of unmanned vehicles traveling over travel routes formed from a plurality of connecting routes which connect nodes constituting stopping positions, said transport management control method comprising the steps of:

• a. determining the optimal travel route of each of a plurality of unmanned vehicles;
• b. finding in the plurality of optimal travel routes obtained in step a. opposite direction intervals comprising travel routes having mutually opposite directions;
• c. halting processing if opposite direction intervals are not present, and if opposite direction intervals are present, then calculating an integral cost for each unmanned vehicle by totaling the costs of the opposite direction intervals in the travel route of each unmanned vehicle;
• d. applying a specified direction to an opposite direction interval on the travel route of the unmanned vehicle having the highest integral cost, so that this interval has one direction;
• e. again determining the optimal travel routes of all unmanned carrier vehicles, with the above-mentioned application of a specified direction to the travel routes;
• and
• f. determining by the repetition of steps b., c., d. and e. optimal travel routes having no conflict;
• g. simulating the temporal movements of the unmanned vehicles in a travel grid based on said optimal travel routes;
• h. if the simulation teaches that an unmanned vehicle has encountered a deadlock problem in which it is unable to advance, then adding a relief route to the travel route of said unmanned vehicle by moving another unmanned vehicle which has already completed its work to a node having the least cost for moving thereto;
• i. if the deadlock problems of all unmanned vehicles encountering deadlock are not able to be resolved by the above-described step h., then changing the sequence in which unmanned vehicles pass through nodes by selecting a reservation sequence of nodes containing unmanned vehicles which are not in a standby state, based on the number of passes which other unmanned vehicles make through the nodes;
• j. if the deadlock problem is not resolved by the above-described step i., then offering a detour route by selecting an unmanned vehicle which is not in a standby state, prohibiting passage through a portion of the travel route of said unmanned vehicle, searching for a detour route to the next node in the travel route of said unmanned vehicle, and substituting the detour route as a new travel route for said unmanned vehicle to move to said next node, or
• k. if the deadlock problem is not resolved by the above-described step j., then offering a passing route for temporarily yielding the right of way to an unmanned vehicle which is encountering the deadlock problem, by temporarily moving an unmanned vehicle which is not in a standby state to a node having the least cost for moving thereto.

An optimal route determination apparatus comprising:

• first cost calculation means, in which, with respect to a set of travel intervals connecting a first and second node which join one another and between which travel is possible, among a plurality of nodes on a travel route, calculates a first cost for each travel interval, based on the distance between the nodes and the movement time;
• second cost calculation means, which, when a target node is directed, calculates the angular difference between the direction of the first node, as seen from the target node, and a prespecified direction, and calculates the angular difference between the direction of the second node, as seen from the target node, and prespecified direction, and based on these angular differences, calculates a second cost for each travel interval;
• addition means for adding the results of the cost calculation of the first and second cost calculation means for each travel interval;
• and
• route generation means, which, based on the added costs calculated by said addition means, selects the case in which the estimated value of the added costs of each travel interval has the smallest value as the optimal route from the departure node to the target node.