Abstract
This paper treats nonlinear control of a hydraulic servo system to suppress micro stick-slip vibrations. The system consists of a hydraulic cylinder, a servo-valve and a personal computer. Self-excited vibrations of two different types occur in the conventional feedback control system. Discontinuous control signal generated through a D/A converter causes a stick-slip vibration of micron order over the wide range of the feedback gain. Increasing the feedback gain results in the other type of stick-slip vibration of nearly ten times larger amplitude due to the locally increased flow gain in the underlap region of the servo-valve. The feedback linearization technique is applied to compensate the nonlinearity of the valve. Numerical simulation and experiment were performed for both the present nonlinear control system and the ordinary linear control system to confirm the validity of the former one in suppressing the micro stick-slip vibration. The other type of micro stick-slip vibration due to the D/A converter was effectively suppressed by improving the resolution of the input signal.
| Original language | English |
|---|---|
| Pages (from-to) | 772-779 |
| Number of pages | 8 |
| Journal | Nihon Kikai Gakkai Ronbunshu, C Hen/Transactions of the Japan Society of Mechanical Engineers, Part C |
| Volume | 64 |
| Issue number | 619 |
| DOIs | |
| Publication status | Published - 1998 |
Keywords
- D/A Converter
- Digital Control
- Feedback Linearization
- Frictional Vibration
- Nonlinear Control
- Nonlinear Vibration
- Oil Hydraulics
- Self-Excited Vibration
- Servo Mechanism
- Stick-Slip Vibration
- Underlap of Spool-Valve