Design of Flight Control System Control Laws

Flight control system control law design serves as the core component in UAV and aircraft development, with the primary objective of ensuring vehicle stability and controllability under various operating conditions.

Control laws typically consist of three main components: Feedback Control: Retrieves aircraft attitude, velocity, and other parameters through sensors, compares them with desired values to generate error signals. Implementation often involves reading sensor data via I/O interfaces and calculating deviations using subtraction operations. Control Algorithm: Processes error signals using PID (Proportional-Integral-Derivative) or its enhanced variants. PID parameter tuning directly impacts system response speed and stability - in code, this involves implementing difference equations for discrete PID calculations with carefully calibrated Kp, Ki, and Kd coefficients. Feedforward Compensation: Injects compensation signals in advance for known disturbances (e.g., wind gusts) to reduce system lag. This requires modeling disturbance patterns and implementing predictive compensation algorithms.

MATLAB implementation typically utilizes the following toolchain: Simulink for building control models and conducting visual simulations, where control blocks can be directly dragged and configured System Identification Toolbox for analyzing aircraft dynamic characteristics, using functions like tfest() for transfer function estimation Automatic code generation features to deploy verified algorithms to hardware through Embedded Coder or similar tools

Advanced development must additionally consider: Multi-loop coupling issues (e.g., roll/pitch channel interference), requiring decoupling algorithms and coordinated control strategies Nonlinear factors (actuator saturation, aerodynamic parameter variations), necessitating gain scheduling or nonlinear control techniques Adaptive control implementations to handle flight envelope changes, potentially using model reference adaptive control (MRAC) architectures