The Research And Implementation Of An Embedded And Constant Length Cut Control System

Constant length cut control is a familiar problem in industrial application. The constant length cut of raw materials is a necessary working procedure, whose automation and cutting precision are very important to the production efficiency and product quality of the whole production line. It also affects the utilization rate of raw materials.After the study on the constant length cut control and the analysis of the current application situation of embedded control systems, this thesis proposes a constant length cut control system which is implemented using two ARM controllers. One is responsible for the human machine interface, and the other is dedicated to motion control and creation of motion curve of step motor. In this way the real-time control is guaranteed, and the flexibility of system design and modification are also improved.The core of a constant length cut control system is motion control, and the choice of the motion curve will decide the motion control performance. Firstly, after comparing linear accelerated curve with the S accelerated curve, the thesis uses the S accelerated curve as the motion curve of feeding motor. Secondly, because of the changeable working states and loads, the IAP(In Application Program) is used in the creation of motion curve. Motion curve can be set freely by the application of this function. Finally, control pulses' transmission makes use of PWM function in the ARM controller, which makes the implementation of various function requirement more reliable and flexible and software programming more easily.The human machine interface module and motion control module are the main modules in the system. The display module adopts LCD panel and the interface design is based on ZLG/GUI, therefore the operation is simplified with more user-friendly interface. For reducing the errors in logic judge and improving clarification of program and comprehensibility of code, the state machine is adopted in the window switching. The motion control module is responsible for pulse transmission, direction control and input-output signals' disposal.The constant length cut control system proposed in this thesis has been applied in pack industry and the system works well. The control precision is also satisfied for the production requirement.