Research And Design On A Kind Of Digital-analog Electro-hydraulic Speed Governor

The speed governor is a key device used for the diesel, which supplies the oil to the diesel engine according to its load so as to control the diesel's speed steadily.The general diesel uses mechanical speed governor to control its speed.But by this kind of governor; it is difficult to regulate the speed exactly and impossible to complete complicated functions.To resolve the above problems, a kind of digital-analog electro-hydraulic speed governor is designed,which consists of the analog electronic speed controller and the ARM-based management system .The speed governor is a multi-functional integrated speed control system,it can regulate the speed of diesel stably ,monitor and display the operation of the diesel and inquire about the history information.The research of this thesis mainly focuses on the following four aspect.1. Based on research and deeply analyse about analog electronic speed governor, a speed governor electronic board is desighed.the board has a high reliability; it is the basis of the whole speed governing system.2. Based on ARM9 hardware platform, Embedded Linux software platform and development tool Qt/Embedded, a monitoring and management system is built.By the system, we can set the system parameter, monitor the operation and inquire about the history information of the diesel engine.Besides, other functions such as remote monitoring,data transferring and on-line internet can added to this system easily.3. A connecting circuit is designed to connect the monitoring and management system to the speed governor.The circuit can transfer the system parameter from monitoring and management system to the electronic board and transfer the opetation parametrt such as speed, temperature, pressure to the monitoring and management system.4. The speed of the diesel is the most critical variable.A speed set-up and detection board is designed for users to set up diesel speed friendly and accurately. Besides, the board can monitor the validity of the speed signal from the two pathways to improve the reliability of the speed control system.The electro-hydraulic speed governor combines the advantages of digital circuit, analog circuit and hydraulic pressure system.It can achieve practical application requirements, and have better control effect.Now the speed governors have been used in several diesel factories successfully.