Research And Design Of The Optimal Control Systems For NC Turret Typing Machine

Aim at the current situation of NC turret typing machine at home and abroad, this paper analyses the current advantages and disadvantages of conventional typing machine and presents the design of the optimal control systems for NC turret typing machine, according to the large range movement and high-precision positioning. The open NC system based on industrial control computer(IPC)and programmable logic controller(PLC) is developed . The specific research contents are listed as follows:Firstly, according to the concept of open NC system, the design for the key technology of hardware units in NC System must be completed on the premise of analysis of the mechanical structure of NC turret typing machine.Secondly, the optimization of the tool path plays a vital role in the process of typing. The efficient optimization algorithm for the tool path could reduce the number of tool changing and optimize the tool path so that processing efficiency could be improved greatly. NC turret typing belongs to multi-point processing, which can be abstracted as the traveling salesman problem(TSP) in the path optimization model. This paper presents a method of path optimization based on genetic algorithm with the study on current optimization algorithm for the tool path.Aiming at the drawbacks of slow convergence speed for crossover operation in genetic algorithms, the algorithm strategy should be selected and applied properly. The system uses "Elite preservation strategy" and greedy crossover operator which can enhance the convergence speed. It also uses "Adaptive mutation strategy" to prevent premature convergence. Finally, The simulation for optimal tool path is carried out with MATLAB, which verifies that the path optimization system has good properties in computation time and solution precision. In a word, genetic algorithm can achieve the path optimization of turret typing machine. Thirdly, the upper and lower control mode which composed of IPC and PLC is proposed in this paper. PLC executes the optimized processing path code which is used to control servo system of NC turret typing machine with X-axis and Y-axis so as to achieve rapid and accurate location; the code also can control the two-way revolution of turret and the nearest tool changing.