Feedback Control of a Digital Hydraulic Operating System (DHOS) Diesel Injector

A new algorithm for injection control has been designed, enabling small, consistent, pilot injection quantities. The control scheme described in this paper is adaptable and software tunable. It enjoys advantages including the ability to compensate for both manufacturing tolerances and operating conditions such as pressure, temperature and injection timing. In bench and dynamometer testing on Sturman Industries' DHOS (Digital Hydraulic Operating System) diesel injector the algorithm has proven its effectiveness for decreasing the minimum stable injection quantity. This data is presented along with results showing improved repeatability at large injection quantities and stable multiple injection sequences. The approach thus provides both improved performance and tremendous flexibility for the injection sequence.