Three-dimensional Traction Bed Control System Design

In this thesis , the designing method of computer-controlled system in three-dimensional drawing bed was discussed and a simple computer-controlled system was developed .The hardware in the system consists of an upper processor and a lower processor . PC is used as the upper processor, which implements the interface between user and computer and completes the input of parameter and command. The lower processor is a P89C51RD2 processor which act as the center of the controlling system. The lower processor outputs controlling instructions according to real-time data of the equipment and result of program running in order to realize determined movement and velocity. The upper processor was developed with Visual Basic 6.0.The lower processor was developed with assemble language which is characteristic of high code efficiency.Three-dimension drawing bed has three motions included main drawing motion, inclining motion and rotating motion .Each motion is independent each other and its movement and velocity must be controlled. In this paper hybrid stepper motor is used as power resource . MCU sends instruction value to chip 8254. As a result chip 8254 produces corresponding rectangular waves which have a definite frequency. When the rectangular waves are transferred to motor driver, the motor is activated at a definite RPM. In order to promote controlling accuracy, feed-back controlling method is adopted. Three sensors are mounted at the equipment side in order to detect the real-time positions of three motions. Depending on a series of calculating ,MCU can decided what to do afterwards after the three real-time positions are sampled. A set of Man-Machine interface is developed with Visual Basic 6.0 to supply convenience to operator. Most job can be completed on this platform.After a large quantity of adjusting work, the lower processor can receive the treatment parameters and command, and execute the command correctly. The experiment shows that the three-dimension drawing bed controlling system can realize all the anticipated functions. This system can be put into practice after further development.