The Research And Application Of Storage/Retrieval Machine Positioning Control System

Storage/retrieval machine is the core operating equipment of automated warehouse. The warehouse which is large capacity and high efficiency requires that Storage/retrieval machines have an further improvement in requirements of reliable, economical and rapidity. The operational efficiency of Storage/retrieval machine in the X, Y, Z three directions and the costs of design and manufacturing of its mechanical part determines the operating efficiency and construction costs of warehouse. Thus, the investigation of the positioning control system of the Storage/retrieval machine has an important practical significance.The positioning control of the Storage/retrieval machine is related to the application of detection technology of cargo positioning recognize site, motor control technology, PLC control technology, the swing control technology of flexible elastic members, and the precise positioning control technology in braking to stop. This thesis, for the impact of mast swing of the positioning control system of the Storage/retrieval machine and the horizontal positioning of the running gear, applies the research methods which include theoretical modeling, designing appropriate control strategies and simulation analysis, we can make the further investigation from the establishment of mechatronics model and the sway mast control and the precise positioning control strategies.Firstly, the positioning control principle of movement of the Storage/retrieval machine in X, Y, Z three directions and the characteristics of the constituent elements are analyzed. the control object and the effect factors of accuracy of the Storage/retrieval machine positioning is defined, such as the problem of mast swing and the large inertia of the Storage/retrieval machine, the sensor noise and high positioning speed etc. Two-step approach of positioning control based on double position loop is designed, the positioning accuracy and fast response is conducted the key performance indicators of positioning control system. The establishment of mechanical transmission model of the storage/retrieval machine electromechanical system, general model of AC servo motor and servo drive model. Through simplified the storage/retrieval machine mast, on the basis of Euler-Bernoulli cantilever beam theory, the kinematics and dynamics model of the storage/retrieval machine mast is built in the progress of acceleration and braking stop.Secondly, through the design of accurate and fast positioning control strategy, it makes that the storage/retrieval machines have a good performance in positioning accuracy, fast response and stability. On the one hand, on the basis of the storage/retrieval machine mast swing characteristics, we design masts swing suppression controller based on input shaping technique, so the storage/retrieval machines can quick stop; on the other hand, the controller based on the structure of the two degrees of freedom makes the storage/retrieval machines have an precise positioning process in the horizontal direction to walk. Combined to the two control modules, it determines the final control program. By means of software Matlab, the establishment of the controller Simulink model can obtain the simulation curve and the comparative analysis of simulation results verify the effectiveness of the controller.Finally, the thesis analyzes the application method of positioning control system of the storage/retrieval machines from these aspects of hardware and software design. The system makes the PLC as the control core, the use of precise positioning control algorithm, the profibus communication methods and barcode positioning precision confirmation addressing mode; these and AC servo systems, mechanical transmission system are consisted of high-precision positioning control system which has an double position loop. From the simulation results, this method can effectively improve the control performance of the storage/retrieval machines. It provides an important reference for the design of the future storage/retrieval machine control system.