Study Of Critical Control Algorithm Of Monitoring System Based On WSN For Tower Crane Groups

Every year, there are many fatal accidents of tower crane in our country, causing huge number of casualties and property losses. Therefore, this paper proposes a program of the monitoring system for group towers based on wireless sensor network, and does the research and analysis about the crane anti-sway algorithm and crane anti-collision algorithm.Firstly, this paper proposes a new program of tower crane monitoring system based on wireless sensor network (WSN) technology which based on ZigBee, and combined with GPRS, CAN bus technology and embedded technology. System is consisted of the crane monitoring terminal and monitoring center platform components. In order to ensure real-time of the system, this paper compares and analyzes the advantages and disadvantages between centralized control mode and distributed control mode, proposes the hybrid control mode combined the advantages of both, and introduces structure and function of the intelligent control system in detail. The wireless network structure of the system is star topology, it can transfer information between the individual controllers and control center in real-time. The system provides a method which is simple, real-time, low cost and high reliability. Secondly, aiming at phenomenon of tower cranes load swinging easily, it needs anti-sway controller to control. This paper establishes a system model by Lagrange equations, analyzes on system stability, controllability and observability. This paper reduces the complexity of the control by using the strategy of controlling the trolley position and angle of load-sway simultaneously. In order to overcome the deficiencies of conventional PID control on tower crane anti-sway control, by determining the domain of the system and the membership function, establishing fuzzy rule table and precisely calculating, and thus designs fuzzy adaptive PID controller of the system. The paper does the simulation experiments of anti-sway controller by using MATLAB/Simulink, and does the performance analysis compared with the conventional PID control. Simulation results show that anti-sway fuzzy adaptive PID controller can quickly achieve precise positioning of the trolley and remove the load sway. Compared with conventional PID control, the controller improves the control performance and has strong robustness. At last, because cross-operation of group tower cranes can easily produce collision between tower crane arms in construction site, this paper uses homogeneous transformation to unify the coordinate. Through the four-dimensional space-time state law, establishes the mathematical model of crane movement, draws the idea of hierarchical bounding box collision detection to establish anti-collision model of tower crane, designs a tower crane anti-collision algorithm by calculating the distance of tower crane arms in real time, and uses MATLAB software to simulate, and verifies the algorithm is effective and real. The simulation results show that the algorithm can prevent collisions in group towers construction site.In summary, this paper designs a program of monitoring system on tower crane groups based on wireless sensor network, and does the research of anti-sway control algorithm and anti-collision algorithm in detail. Simulation studies show that:the system can effectively control the crane load-sway, and can effectively prevent the collision between the cranes and prevent accidents to happen.