Qin Zhang is an assistant professor at the University of Illinois at Champaign-Urbana developing a programmable electrohydraulic (EH) control valve. The new device consists of five proportional-flow control valves that are used with a hybrid control algorithm. Zhang and colleague Haibo Hu published a paper outlining their conclusions: They say it is technically feasible to integrate a programmable valve using five individually controlled proportional valves. It is important to obtain the characteristics of sub-valves before the integration, say Zhang and Hu. They also assert that the use of a simple logic control algorithm is sufficient for achieving programmable valve features such as open center, closed center, tandem center, and float center. For more information, call Zhang at (217) 333-9419 or visit www.uiuc.edu.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.