The Control System Of Multi-point Forming Equipment Based On Industrial Fieldbus

Multi-point forming is the sheet metal forming three-dimensional surface of flexible processing methods, it adopts a series of the basic body of regular array and adjustable height composed of multi-point flexible mold . The control system of multi-point forming equipment uses computer to control displacement and speed of basic body, in order to achieve the change of enveloping surface with flexible forming. Compared with traditional methods of forming die, multi-point forming equipments realize the conceive of multi-purpose machine.The multi-point forming control system is an important part of its equipment, and its study on the practical application of multi-point forming technology and device is of great significance. Parallel adjustment is a rapid adjustment technology, all the basic body can make adjustments at the same time, speed up adjusting speed of multi-point forming equipment, so greatly improve adjusting efficiency of multi-point forming equipment.Functional requirements of the control system based on the multi-point forming equipment, on the base of previous research work, a distributed control system of distributed computer that based on RS-485 bus completes design and development of parallel adjusting system. The main contents and conclusions of research work are as follows:1. In the past, the adjustment means of multi-point forming system are not serial but parallel, serial adjustment means lower cost of machinery and equipment but increase too long time when they work, so the efficiency is too low; in the way of parallel adjustment, each basic body counterparts a motor, time of adjustment is reduced by double, but the cost along with it increase, and due to the numbers of motor too many ,so the basic body of smaller bulk and the equipment of higher precision can not achieve because there is no place for motors, the paper adopts mixed adjustment which takes account of adjusting time as well as solves the problem of precision, especially applicable to micro-device of smaller basic body.2. To meet the system requirements, put forward the communication protocol of PC and terminal unit, it is composed of initial frame, address frame, data frame and end frame, contains all the transfered information between PC and terminal unit, and there are even and odd test functions; discuss the problem of the RS-485 communication bus fabrication and design the reliability of bus to ensure it good operation.3. Using VC++6.0 compiled adjusting software. The software achieves the setting parameters, leveling, adjusting type and so on, and analyses the results as well as power control. Monitoring software receives data files that are transmitted by multi-point forming CAD software system, set up control methods and device parameters after the data-processing and send data and command to the control unit, control implementing agencies of press, construct the group forming surface of basic body, and then forming parts that we are required by controlling organization of load. In the process of adjustment, the PC can detect, display, judge state parameters of enforcement agencies. It will continue to communicate with terminal unit and record performance if state parameters are normal, and wait for the shutdown orders; detect the record of routing whether or not accords with requirements of precision, if not, then generate new data files, continue to adjustment until it meets the requirements of precision. In the process of adjustment, if state parameters of implementing agencies are abnormal, then shutdown, warning and displaying the point of malfunction; after eliminating, the system re-initialized. In practical applications, the monitoring software has achieved good results.4. Using three-phase bridge rectifier circuits provides low-voltage DC high-power power supply for the control system of multi-point forming equipment. Meet the electrical need of the control unit and other components.With the rapid development of modern industries, the sorts of product are more and more, and the speed of replacement is more and more fast, so production quantities turn to small quantities, coupled with development of the auto industry and the aerospace industry, the need for multi-point forming technology improvements. But control system of multi-point forming is a very complex technology, it occupies a very important position in multi-point forming technology , the extent of its research directly restricts development of multi-point forming technology, which involves the computer, electronics, machinery and many other subjects, so there are many issues to be studied further.