Robust Rate Control System Designs for a Submersible
Abstract
Two robust rate control system designs are carried out for a submersible (modeled by the NSRDC 2510 equations) in a turn using the Linear Quadratic Gaussian approach with Loop Transfer Recovery. Separate command channels allow the submersible to maneuver independently in horizontal and vertical planes; the vehicle operator controls bearing and depth rates through a joystick-like device. Fin configuration is the conventional cruciform stern without differential control. The first compensator design r - theta controller directly controls two vehicle state variables: pitch theta and vehicle angular velocity, r, about the z-axis. The other system (the psi - z controller), controls yaw (or heading) rate psi and depth rate (z) directly. However, this design relies on linearized equations of yaw and depth rate to be employed by the compensator for state reconstruction. A tool for Kalman Filter loop shaping is developed in which state variables are scaled to provide good loop shapes and then recovered to get controllers that are robust. Both controllers are compared on the basis of performance in a nonlinear simulation. A robustness comparison is also conducted. Based on limited simulation data, this thesis concludes that the psi - Z controller provides better control of depth rate than the r - theta controller. Bearing rate performance is essentially equal in both designs; however, the psi - z controller appears less robust in certain frequency ranges.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1984
- Accession Number
- ADA144792
Entities
People
- Lawrence J. Dreher
Organizations
- Massachusetts Institute of Technology