The Design Of Construction Elevator’s Intelligent Leveling Control System

The great development of construction industry proposes high demand ofintelligence, efficiency and security during the process of construction. Theconstruction elevator serves as a necessary facility for vertical transportation, itscontrol system has many disadvantages such as low accuracy, low efficiency, lowcomfort degree and low intelligent level. It cannot meet the demand of productio nand improvements are required. So we develop a more intelligent construc tio nelevator control system. The research contents include3parts.First, the issue has studied the driven method and torque distribution of3motorson the construction elevator. The variable frequency speed-regulating vectortechnology are used to control the motors and it makes the construction elevatorworking more smoothly. Then a master-slave motor control scheme is designed tosolve the problem of3motor’s torque are equaled while their speed are same. We usespeed close-loop control on the master motor and the slave motor will follow themaster motor’s torque. Then the problems of multi-motor’s coordination and torquedistribution are solved. The motor’s loss are reduced and the reliability of system areincreased at the same time. At last we build a3-motor master-slave control model byMatlab/Simulink. The simulation results have proved the feasibility of master-s la vemotor control scheme.Second, the issue has studied the realization method of construction elevato r’sintelligent leveling. The automatic leveling strategy is designed considering thespeed/location and weighing signal from external sensors, and BP neural networkalgorithm is used to calculate the stopping distance. Such a control model is built andwe simulate by Matlab about the train and application of the model. Considering theoffline algorithm depending on samples and disability with time-variation system, wefurther propose an online algorithm. It keeps training in using and it fully impro vesthe level accuracy.Third, the implementation of hardware and software and functional verifica tio nare completed. We have designed hardware test device of construction elevatorcontrol system. The part of hardware circuit design includes a master control boardwhich has a DSP F28335(TI) served as control core. The board has realized functio nsincluding controlling, collecting of signal from sensors, communicating withfrequency converter, saving/showing and port of wireless communication. Finally anexperimental platform is set up with the board, ATV71series frequency converte r,three-phase asynchronous motor and external sensors. Then, we complete theprogram about control algorithm and functions in CCS3.3, and begin furtherdebugging and studying. Then the accuracy of system design is verified at last.