The Ball - Pole Monitoring And Control System Development And Research

Ball-beam is a non-linear, unstable, mechanical and electrical combination system; it is of great significance to the research of the dynamic system modeling and to verifying the stability, the rapidity, the accuracy of control algorithm. Many researchers have done a lot of work in the modeling and the digital simulation of ball-beam system at home and abroad. However, with the complexity of control algorithm, the shortcomings of RS232 in data acquisition frequency and real-time communication performance become increasingly obvious.This research is to design and realize the measurement and control system for the ball-beam system:the communication between PC and MCU is based on USB (Universal Serial Bus); the measurement and control platform is based on MCU; the PC software platform is based on LabVIEW. This thesis has accomplished the following work::1. After analysing some drawbacks of RS232 in communication speed, reliability, and usability this thesis uses an embedded solution based on USB, which is proved to satisfy the demands for the motor drive capacity and the sampling frequency.2. The subordinate measurement and control system is based on a micro-controller system, which includes a counting module to measure the motor speed through the two-phase encoder, and an analog acquisition circuit to measure the ball's position on the beam, and a power-driving module to drive DC motor, and a USB function module in order to achieve real-time data communication with the host computer.3. With Keil C51 as the software development kit, the measurement and control program is a combination of assembly program and C program, which includes the USB firmware, the data acquisition program, and the program for driving the DC servo motor, to accomplish the function of the measurement and control system in communication, data acquisition, and control.4. The human-machine/operator interface is based on LabVIEW which is also used to accomplish the control algorithm. The LabVIEW-based interface is friendly with a great data-visualizing function. The connection between the LabVIEW program and the Windows driver software is established by using the library function nodes of LabVIEW, which makes it easy to operate the ball-beam system just like operating a file document on the computer.5. Taking NI ELVIS virtual oscilloscope and its supporting hardware as a debugging platform, and BusHound and IRPTrace as a monitoring software for the enumeration procedure, we optimized the application program on PC and MCU to achieve faster speed and higher reliability of data communication. The performance of the measurement and control system is tested, which shows a successful, stable and reliable system.