Research Of Operation Conditions Monitoring System For Tower Crane

In the housing architectural engineering, many hoisting machineries can be used to finish the vertical translation and horizontal movement of heavy loads in the same time, but lifting appliance used most widely is tower crane. The tower crane provide several significant advantages compared to other lifting appliance, such as the high tower, the long crane boom and the broad effective area of operation, it can finish the action of hoisting, slewing, walking and luffing. Meanwhile tower crane is the mechanical equipment with a lot of risk factors and high probability of accidents, once accident occurs, the damage and harm is extremely serious, either suffering injury or personnel casualty, the consequences not only lead to tremendous losses of people’s lives and property but also relate to the economic development and social harmony and stability. Thus, how to enhance the safe operation of tower cranes, has received the manufacturer, the building construction enterprise, the safety surveillance department and the construction administration department highly attention. GB/T5031-2008tower crane standard developed by nation latest, which require all types of lifting machinery must be equipped with safety devices to ensure the operational safety of tower crane.At present, the existing tower crane protection devices just stay at the stage of "four limiters two insurances", four limiters including torque limiter, high limiter, luffing limiter and walk limiter, two insurances including hook insurance and coiling block insurance. The safety protection devices can not complete display of relevant parameters, and alarm only in the case of reaching the limit, so their reliability is low. In view of above existence question, on the basis of analysis about the structure and security of tower crane, the several key operational parameters, such as the hoisting weight, lift height, turning angle, lifting torque, working radius, wind speed of jobsite, were studied as the representative and an operation conditions monitoring system of tower crane was developed.The system takes STC12C5A60S2microcontroller as processing core, the key information of hoisting weight, lift height, turning angle, lifting torque, working radius, wind speed of jobsite were collected by shaft pin sensor, incremental encoder, absolute encoder, wind speed sensor. The system has a good human machine interface parameter setting functions and display feature, finishing the related parameters display for operation conditions of tower crane through the LCD, according to tower machine itself unique parameter, the operator can set or modify the security parameters of tower crane through keyboard. The recent20times aberrant operating mode data saved by nonvolatile data storage can provide analysis of the accidents for tower crane supervision department. In addition, the system is equipped with photoelectric coupling output interface, to achieve the stop of all operating mechanism for tower crane. In the time of overrun and overload caused by operational errors of operator, sound and light alarm circuit work and automatically cut off the control circuit to dangerous direction to reach purpose of safety monitoring for tower crane. Considering the poor working environment of tower crane, in the design of hardware circuit, photoelectric isolation technology, decoupling and filtering technology were used to improve the system’s reliability, in the course of software design, some measures, such as software watch dog, software filtering, were used to enhance the system’s anti-jamming capability. In the last of paper, debugging the hardware and software of circuit board and verifying the basic functionality of system.The system is a work status monitoring system for tower crane based on the basis of traditional mechanical and electronic sensors and combined with current digital processing technology, the sensor technology, the filter technology. The system has a good real-time performance reliability and wide application value, it meet the development direction of miniaturization and intellectualization of crane intelligent monitoring system.