Abstract
Most nonlinear dynamic systems do not lend themselves to simple closed-loop control strategies. However, computational methodologies are now available to analyze such nonlinear systems and design/optimize their open-loop control strategies. In this work, we augment the optimal open-loop scheme with a closed-loop scheme. We linearize the equations of motion about the optimal open-loop trajectory. The resultant linear time-varying system is controlled by a simple feedback law. The proposed control scheme can be used to design controllers for a wide array of nonlinear dynamic systems, e.g. manufacturing systems. Here, we design and implement a controller for a single flexible link. It is well known that noncollocated control of a flexible link results in unstable closed-loop behavior and that stable collocated feedback fails to adequately suppress the residual tip vibration. The proposed control methodology combines the optimal open-loop scheme that is designed to suppress residual tip vibration with stable collocated feedback. A nonlinear dynamic model, based on finite strain rod theory, is used with sensitivity analysis and numerical optimization to obtain the optimal open-loop scheme. Simulation and experiment are used to evaluate and compare the performances of the proposed open-loop controller, the proposed closed-loop controller, and a traditional proportional-derivative collocated feedback controller.
Original language | English (US) |
---|---|
Pages (from-to) | 645-654 |
Number of pages | 10 |
Journal | Collection of Technical Papers - AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference |
Volume | 1 |
State | Published - 1997 |
Event | Proceedings of the 1997 38th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference. Part 4 (of 4) - Kissimmee, FL, USA Duration: Apr 7 1997 → Apr 10 1997 |
ASJC Scopus subject areas
- Architecture
- Materials Science(all)
- Aerospace Engineering
- Mechanics of Materials
- Mechanical Engineering