A Hybrid Digital Hydraulic Servo
650317
02/01/1965
- Event
- Content
- In many applications, control system equations are being processed in a digital computer. Digital-to-analog (D/A) converters are then used to make command signals compatible with analog final control elements. It is more desirable to design a highly integrated system which uses a digital servo and does not require D/A conversion. However, digital hydraulic servo valves have not yet been highly developed, and some types are quite complex.It was the object of this program to design a hydraulic digital servo which uses the standard, proven two-stage electrohydraulic servo valve. This was done by having the servo valve itself perform the function of a D/A converter. It accepts digital signals in computer format and quantizes actuator velocity. Initial design studies were performed, followed by analog and digital computer studies. A breadboard unit was built and evaluated. Two main conclusions have thus far been reached:
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Performance comparable to analog servo systems can be obtained with the hybrid.
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The basic concept provides inherent redundancy, thus high reliability; the hybrid servo operates at reduced performance with most single failures.
Experimental as well as analytical data are presented in the paper. -
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- Pages
- 13
- Citation
- Yount, E., and Stiglic, P., "A Hybrid Digital Hydraulic Servo," SAE Technical Paper 650317, 1965, https://doi.org/10.4271/650317.