Nonlinear 3D Spiral Trajectory Tracking of a 3-DOF Helicopter: A Comparative Analysis of SDRE and Successive Approximation Strategies
12th International Conference on Control, Decision and Information Technologies, CoDIT 2026, Bari, İtalya, 13 - 16 Temmuz 2026, ss.3058-3063, (Tam Metin Bildiri)
- Yayın Türü: Bildiri / Tam Metin Bildiri
- Doi Numarası: 10.1109/codit70676.2026.11631284
- Basıldığı Şehir: Bari
- Basıldığı Ülke: İtalya
- Sayfa Sayıları: ss.3058-3063
- Gazi Üniversitesi Adresli: Evet
Özet
This paper compares State-Dependent Riccati Equation (SDRE) and Successive Approximation (SA) controllers for trajectory tracking of a nonlinear three-degree-of-freedom (3-DOF) laboratory helicopter. Both methods provide approximate routes to nonlinear optimal control problems associated with the Hamilton-Jacobi-Bellman (HJB) equation, but they treat the nonlinear dynamics differently. SDRE preserves a state-dependent coefficient representation, whereas SA repeatedly solves locally linearized subproblems. Two simulation scenarios are considered. The first scenario uses step commands with a severe wind-gust interval to verify nominal tracking and disturbance rejection. The second scenario imposes a three-dimensional spiral reference and an asymmetric wind gust to test sustained nonlinear maneuvering. Under the tested conditions, both controllers track the step commands satisfactorily, while the SDRE controller gives smoother responses and lower time-weighted tracking errors in the spiral case. The comparison is quantified using Integral of Time-weighted Absolute Error (ITAE), Integral of Time-weighted Squared Error (ITSE), total quadratic cost, control behavior, and computation time. The results should be interpreted as evidence for the considered benchmark and scenarios rather than as a universal ranking of the two methods.