Automated guided vehicle system based on autonomous mobile technique and a method for controlling the same

• US 10,223,916 B2
• Filed: 07/15/2016
• Issued: 03/05/2019
• Est. Priority Date: 07/17/2015
• Status: Active Grant

• Current Assignee: Korea University Research and Business Foundation
• Original Assignee: Korea University Research and Business Foundation
• Inventors: Song, Jae Bok, Son, Jung Ho, Jung, Min Kuk, Park, Chan Soo
• Primary Examiner(s): Shafi, Muhammad
• Application Number:
  US15/211,215
• Publication Number:
  US 20170017236A1
• Time in Patent Office: 963 Days
• Field of Search: 701 23
• CPC Class Codes: G05D 1/024 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/0274 using mapping information stored in a memory device navigation using map-matching G01C21/30
• CPC Class Codes: G08G 1/164 Centralised systems, e.g. external to vehicles
• CPC Class Codes: G08G 1/165 for passive traffic, e.g. including static obstacles, trees

Abstract

The present invention provides an autonomous mobile-based automated guided vehicle system comprising a system input unit configured to set and input a mobile path between a departure point and an end point of the autonomous mobile-based automated guided vehicle as one or more mobile path blocks in the unit of a block, a system control unit configured to apply a control signal to a corresponding autonomous mobile-based automated guided vehicle based on one or more mobile paths in the unit of a block and a system storage unit configured to store the mobile paths in the unit of a block, which are inputted by a user through the system input unit, and a method for controlling the autonomous mobile-based automated guided vehicle system.

Claims

1. A method for controlling an autonomous mobile-based automated guided vehicle system that controls at least one autonomous mobile-based automated guided vehicle comprising a vehicle sensor unit, a vehicle drive unit configured to drive a vehicle body having mounted thereon the vehicle sensor unit, and a vehicle control unit connected to the vehicle sensor unit and the vehicle drive unit and configured to control the drive of the drive unit, the method comprising:

a mobile path setting step of providing one or more mobile path blocks to an operator through a user interface of a system input unit, each mobile block including a preset path information, receiving instructions from the operator on selection and arrangement of the mobile path blocks through the user interface, and setting by the system input unit a mobile path of the at least one autonomous mobile-based automated guided vehicle as one or more mobile paths in the unit of a block based on the arrangement and selection of the mobile path blocks received through the system input unit;

storing in a system storage unit the mobile path in the unit of a block inputted through the system input unit;

transmitting a sensing signal and travel information from the autonomous mobile-based automated guided vehicle to the system control unit;

a travel control step including generating an autonomous travel control signal by a system control unit based on the mobile path and the sensing signal, and applying the autonomous travel control signal by the system control unit to the autonomous mobile-based automated guided vehicle to control the travel of the automated guided vehicle; and

transmitting travel information of the autonomous mobile-based automated guided vehicle to the from a communication unit of the autonomous mobile-based automated guided vehicle to the system control unit;

wherein the autonomous mobile-based automated guided vehicle is provided in plural numbers,

wherein the travel information comprises mobile path information and an actual travel velocity of the autonomous mobile-based automated guided vehicle, and

wherein the travel control step further comprises a collision control step of controlling a vehicle collision between the autonomous mobile-based automated guided vehicles to prevent the vehicle collision therebetween using the travel information of the autonomous mobile-based automated guided vehicle, which is received through a communication between the system control unit and the autonomous mobile-based automated guided vehicle, the collision control step including determining by the system control unit whether or not a collision between the autonomous mobile-based automated guided vehicles is predicted at a collision prediction block as an intersection point of mobile path blocks of the autonomous mobile-based automated guided vehicles based on the travel information.

2. The method according to claim 1, wherein the collision control step comprising:

a travel information collection step of collecting the travel information of the autonomous mobile-based automated guided vehicle through the communication between the system control unit and the autonomous mobile-based automated guided vehicle;

a detour path presence confirmation step of allowing the system control unit to confirm whether or not there is a detour path of the autonomous mobile-based automated guided vehicles based on the travel information if it is determined in the collision determination step that the collision between the autonomous mobile-based automated guided vehicles is predicted;

a detouring determination step of determining whether or not to perform a detouring operation if it is confirmed at the detour path presence confirmation step that there is the detour path of the autonomous mobile-based automated guided vehicles; and

a collision mode execution step of selecting and controlling an corresponding mode of a detouring mode in which the autonomous mobile-based automated guided vehicles travel along the detour path and a velocity control mode in which the travel velocity of the autonomous mobile-based automated guided vehicles is controlled based on a result of the determination at the detouring determination step.

3. The method according to claim 2, wherein the detouring determination step comprises:

a detour path presence determination step determining whether or not a detour path is present based on a result of the execution at the detour path presence confirmation step;

a virtual travel time confirmation step of if it is determined in the detour path presence determination step that the detour path is present, confirming a virtual velocity control travel time spent for the autonomous mobile-based automated guided vehicle to travel through the reduction of the travel velocity at a preset reduction ratio on a scheduled path of the autonomous mobile-based automated guided vehicle, and a virtual detour control travel time spent for the autonomous mobile-based automated guided vehicle to travel on a detour path of the autonomous mobile-based automated guided vehicle; and

a detouring decision step of deciding whether or not the autonomous mobile-based automated guided vehicle detours through a comparison between the virtual velocity control travel time and the virtual detour control travel time.

4. The method according to claim 3, wherein the collision mode execution step comprises:

a detouring mode execution step performed if it is determined in the detouring decision step that the autonomous mobile-based automated guided vehicle detours along the confirmed detour path; and

a velocity control mode execution step performed if it is determined in the detouring decision step that the autonomous mobile-based automated guided vehicle does not detour along the confirmed detour path.

5. The method according to claim 4, wherein if it is determined in the detour path presence determination step that the detour is not present, the velocity control mode execution step is performed in which the system control unit controls the travel velocity of the autonomous mobile-based automated guided vehicle using deceleration reference order data and a reduction ratio, which are stored in the system storage unit.

6. The method according to claim 2, wherein the collision determination step comprises:

a prediction arrival time calculation step of calculating a prediction arrival time difference from a prediction arrival time of the autonomous mobile-based automated guided vehicle to a collision prediction block;

a collision prediction reference time calculation step of calculating a collision prediction reference time for determining that the autonomous mobile-based automated guided vehicles are predicted to collide with each other at the collision prediction block; and

a collision prediction determination step of determining whether or not a collision between the autonomous mobile-based automated guided vehicles is predicted at the collision prediction block using the prediction arrival time difference and the collision prediction reference time.

7. The method according to claim 4, wherein the velocity control mode execution step comprises:

a velocity control priority confirmation step of allowing the system control unit to confirm the travel priorities of the autonomous mobile-based automated guided vehicles, which are included in preset data that is previously stored in the system storage unit, and confirming and selecting the velocity reduction for an autonomous mobile-based automated guided vehicle having a lower travel priority; and

a velocity reduction coefficient assignment step of assigning a velocity reduction coefficient for a mobile path block on a current mobile path of the autonomous mobile-based automated guided vehicle for which the velocity reduction is confirmed and selected in the velocity control priority confirmation step, and reducing the travel velocity of the autonomous mobile-based automated guided vehicle.

8. The method according to claim 4, wherein a plurality of mobile paths is formed on the mobile path blocks, and the system storage unit has stored therein information of a switch block where the number of the entry and exit directions of the autonomous mobile-based automated guided vehicle is less than twice the number of the plurality of mobile paths among the mobile path blocks, and

wherein the collision mode execution step further comprises a switch block control step of allowing the system control unit to confirm whether or not the autonomous mobile-based automated guided vehicle approaches a preset distance with respect to the switch block and control the travel of the autonomous mobile-based automated guided vehicle at the switch block.

9. The method according to claim 8, wherein the switch block control step comprises:

a switch block preset distance approach confirmation step of allowing the system control unit to confirm whether or not the autonomous mobile-based automated guided vehicles enter a preset number of mobile path block distances with respect to the switch block; and

a switch block distance entry determination step of allowing the system control unit to determine whether or not a distance between the autonomous mobile-based automated guided vehicle and the switch block is within the preset distance using a confirmation result in the switch block preset distance approach confirmation step.

10. The method according to claim 9, wherein the switch block control step further comprises:

a switch block entry standby step of, if it is determined in the switch block distance entry determination step that autonomous mobile-based automated guided vehicle enters the preset distance with respect to the switch block, applying an entry standby signal to the autonomous mobile-based automated guided vehicle; and

a travel directionality and travel priority confirmation step of confirming the travel directionality of the autonomous mobile-based automated guided vehicle and the travel priority of the autonomous mobile-based automated guided vehicle, which is included in the preset data.

11. The method according to claim 10, wherein the travel directionality and travel priority confirmation step comprise performing a switch block ON mode of, if the travel directionalities of the autonomous mobile-based automated guided vehicles that stand by at both ends of the switch block are different from each other, allowing an autonomous mobile-based automated guided vehicle having a higher travel priority of the autonomous mobile-based automated guided vehicles to travel in a prior order so that an autonomous mobile-based automated guided vehicle having a lower travel priority enters the switch block after escaping from the switch block or a region formed by the switch block.

12. The method according to claim 11, wherein the switch block ON mode comprises:

a higher-priority vehicle travel and passage step of allowing the autonomous mobile-based automated guided vehicle having a higher travel priority of the autonomous mobile-based automated guided vehicles to travel in a prior order and pass through the region formed by the switch block;

a corresponding path travel directionality switching step of switching the travel directionality at the switch block for a mobile path along which the autonomous mobile-based automated guided vehicle having a higher travel priority travels;

a lower-priority vehicle travel and passage step of allowing the autonomous mobile-based automated guided vehicle having a lower travel priority to enter the switch block and pass through the region formed by the switch block; and

a corresponding path travel directionality switching step of switching the travel directionality at the switch block for a mobile path along which the autonomous mobile-based automated guided vehicle having a lower travel priority travels.

13. The method according to claim 10, wherein the travel directionality and travel priority confirmation step comprises performing a switch block OFF mode of, if it is determined that the travel directionalities of the autonomous mobile-based automated guided vehicles that stand by at both ends of the switch block are identical to each other, allowing an autonomous mobile-based automated guided vehicle having a higher travel priority of the autonomous mobile-based automated guided vehicles to travel in a prior order so that the autonomous mobile-based automated guided vehicle enters a region formed by the switch block, and an autonomous mobile-based automated guided vehicle having a lower travel priority also enters the region formed by the switch block after a preset time has been lapsed.

14. The method according to claim 13, wherein the switch block OFF mode comprises:

a higher-priority vehicle prior travel step of allowing the autonomous mobile-based automated guided vehicle having a higher travel priority to travels in a prior order so that the autonomous mobile-based automated guided vehicle enters the region formed by the switch block;

a lower-priority vehicle posterior travel step of allowing the autonomous mobile-based automated guided vehicle having a lower travel priority to also enter the region formed by the switch block after the preset time has been lapsed;

a corresponding path travel directionality switching step of, if the autonomous mobile-based automated guided vehicle having a lower travel priority deviates from the region formed by the switch block, switching the travel directionalities at the switch blocks for the mobile paths of the autonomous mobile-based automated guided vehicle having a higher travel priority and the autonomous mobile-based automated guided vehicle having a lower travel priority.

15. A combination of at least one autonomous mobile-based automated guided vehicle and a vehicle guiding system, wherein:

the at least one autonomous mobile-based automated guided vehicle comprises a vehicle sensor unit, a vehicle drive unit configured to drive a vehicle body having mounted thereon the vehicle sensor unit, and a vehicle control unit connected to the vehicle sensor unit and the vehicle drive unit and configured to control the drive of the drive unit,

the vehicle guiding system is spaced apart from the at least one autonomous mobile-based automated guided vehicle, the vehicle guiding system comprising;

a system input unit configured to set and input a mobile path between a departure point and an end point of the autonomous mobile-based automated guided vehicle as one or more mobile path blocks in the unit of a block, each of the mobile blocks including a preset path information, wherein the system input unit provides the one or more mobile path blocks to an operator through a user interface and receives instructions from the operator on selection and arrangement of the mobile path blocks through the user interface,

a system control unit configured to apply a control signal to a corresponding autonomous mobile-based automated guided vehicle based on one or more mobile paths in the unit of a block, which are inputted through the system input unit and a sensing signal detected by the vehicle sensor unit to control the path movement of the corresponding autonomous mobile-based automated guided vehicle, and

a system storage unit configured to store the mobile paths in the unit of a block, which are inputted by a user through the system input unit.