Integrated Navigation Control And Research On Scheduling Method For Multi-AGVS System

AGV (Automated Guided Vehicle) is an important part of the flexible manufacturing industry and navigation control and scheduling method are the key technology of AGV design. Integrated navigation system can process a variety of data through the filter. The AGV scheduling system can plan the path under the constraint conditions efficiently. An excellent scheduling system can achieve accurate position, rapid response and timely process barriers, conflicts. In theory, this is a combinatorial optimization problem and more difficult to describe, optimize and calculate, compared with the general scheduling optimization problem. In engineering application, the method proposed in this paper can effectively solve the real time workshop scheduling problem and has important engineering application value.Supported by the National Natural Science Foundation, this paper studies the AGV integrated navigation and positioning technology and the real-time schedule method of multi-AGVs system. This paper studies the integrated navigation and positioning technology including inertial unit and magnetic navigation unit and the framework of solving static scheduling, real-time scheduling problem through the research of execution process about multi-AGVs system scheduling task.The main work of this paper is as follows:(1) Industrial controller based on LPC2388, a sensor MPU9255 and MS20-150 magnetic sensor regarded as the hardware design platform, this paper studies four key technology of AGV navigation:AGV attitude calculation, signal filtering, AGV kinematics model derivation and integrated navigation and positioning method.In this paper, Quaternion is chosen to calculate the attitude, and the complementary filtering algorithm is adopted to correct the attitude by the measure value of the accelerometer and magnetometer. At the same time, this paper established two wheeled differential drive kinematics model, and AGV’s position and heading direction is corrected in accordance with the absolute position of the magnetic nail known to achieve accurate navigation and positioning.(2) With static workshop AGV scheduling problem as the research object, this paper builds the two-stage workshop scheduling system to solve the real-time operation state of the system acquisition, off-line shortest path generation library generation and online optimal scheduling scheme generation. In the offline phase, the shortest path library is constructed by rules and Dijkstra algorithm to avoid the quality of the solution is low in the online phase. In the online phase, this paper controls the time window of AGV in each node and link and adopts the improved micro genetic algorithm to solve the static workshop scheduling problem considering the running time, parking times and turning times.(3) In order to solve the real time workshop scheduling problem, this paper proposes schemes to solve three kinds of workshop floor scheduling problems including free of obstacles in the workshop, the failure of the road of the workshop and the failure of the node in the workshop, which has been verified by the examples. Tests show that the real-time scheduling scheme generally converges at about 10-12 generations, and when a fault occurs in the workshop, the alternative path number of the library path AGV decreases to make the computation time of path optimization reduce and contributes to achieve the rapid response for system. In addition, the fitness value of the scheduling scheme is improved gradually, which both significantly reduces the blocking times and turning times and improves the efficiency and stability of the system. Besides, this paper introduces the map generation of scheduling system in workshop, wireless information transmission and AGV control module, and the function of dispatching system was verified by simulation module.In this paper, the problem of multi-AGVs system integrated navigation and positioning and the method of solving real time scheduling problem are presented. And the key technology and system prototype of integrated navigation hardware, path optimization algorithm and software scheduling related functions are given. This method is helpful to solve the problem of multi-AGVs scheduling in the production workshop and it is expected to be applied to solve the multi-AGVs scheduling problem in the other areas of the port, airport, and logistics and so on.