The Research And Exploitation Of A High-Precision Digital Control System For A Boring Machine Which Is Driven By Intelligent Material

Giant Magnetostrictive Actuator, which is made of Giant Magnetostrictive Material, has several inherent advanced properties such as large strain, quick responding, high output force, etc. It has a promising applied perspective in Precision Processing Field. This dissertation, with the topic of "The Exploitation and Implementation of a High Precise Digital Control System for Boring Processing Driven by Intelligent Material", and based on the state 863 research program "A High Precise Digital Control Boring Machine Embedded with GMA for Non-circular Pinhole Processing", is focused on the construction of a close-loop feedback control system for the Boring Machine.Non-circular pin hole has a significant meaning in ameliorating the stress distribution of the piston, increasing its capability of bearing, prolonging the service life of the piston, as well as the exploitation of highly turbocharged engine. However, due to the difficulty of processing abnormal piston's pin hole, Non-circular pin hole is not yet widely used. Researchers, both domestic and abroad, have been involved in the research of processing methods for abnormal pin hole for many years, and the processing methods have been improved from mechanical nc-copy machining to NC machining. In order to realize the precision machining, how to design a practical abnormal pin hole precise boring control system has therefore been pivotal.The dissertation has summarized and analyzed the current domestic and abroad research works in control systems of non-circular pin hole manufacturing, as well as other technologies which are relevant to this topic.Then this paper elaborates the establishment of the overall scheme of the high precise digital control system for the non-circular pinhole processing. This section includes:the principle and implementation of the non-circular pinhole processing, the hardware constitution of the digital control boring machine as well as the control system, the closed-loop improvement of this system, as well as the establishing of the control plan.After that, the details about the hardware design of the control system are presented. Commonly-used measure methods of the radial feeds of the boring tool are introduced and compared. Afterwards, an improved measure method is devised and realized. Meanwhile, the performance parameter of the DSP board, the design of a high performance D/A conversion interface and its improvement, the filtering and noise reducing of the analog signal of the eddy current transducer, as well as the design of the level conversion interface, are included in this section. Afterwards, this paper focuses on the exploitation of the software of the control system. This section illustrates the design of the software framework of the digital control system, as well as detail programming, such as the program of A/D and D/A conversion, the algorithm of the radial displacement measurement, the PED algorithm, the implementation of the SCI communication between DSP and PC, and the interrupt service routine. Chapter 5 lays out the experiment and its result of this control system. The experiment is divided into two sections. One is the testing of separate circuit boards and the hardware system as a whole, the other is the debugging of separate software modules and the whole software system. Actual machining of the boring machine which is equipped with the closed-loop feedback control system is also operated, and the performance is analyzed in this chapter.In the last section, the main conclusions of the dissertation are summarized, and the further research work which is worthy to be done is listed.