Prediction of Longitudinal Pilot Induced Oscillations Using the Optimal Control Model
Abstract
This thesis evaluates the OCM in predicting handling qualities and PIO pilot ratings during the approach and landing task. Using two existing PIO databases, analytical prediction schemes were developed using the OCM. The prediction schemes used were flight path error and crossover frequency. The prediction schemes were applied to 12 different aircraft/flight control system landing configurations. The 12 configurations were flight tested using a USAF/ calspan variable stability NT-33A. The OCM was able to predict pilot handling qualities ratings (PHQR) accurately (within one pilot rating) 80% of the time. PIO ratings were accurately predicted 96% of the time. Due to a PIO rating problem in the original databases, the PIO prediction schemes were modified using flight test data. Additional flight test configurations should be flown to verify the revised flight path error and crossover frequency prediction schemes. Because of the subjective nature of PHQRs and PIO ratings, the flight test results varied between pilots. The correlation between multiengine pilots was better than with the fighter pilot. The crossover frequency prediction scheme was the most accurate predictor of pilot ratings, while the flight path error prediction scheme was slightly more accurate for PIO ratings. Both predictors agreed with classical control theory, showing correlation between flight path error, crossover frequency, and pilot/PIO ratings. The flight path error and crossover frequency rating prediction methods should be used as a tool in flight control system design.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1989
- Accession Number
- ADA220593
Entities
People
- Steven W. Lindsey
Organizations
- Air Force Institute of Technology