Moghadaszadeh Bazaz S, Bohlouri V, Jalali Naini S H. Attitude Control of a Rigid Satellite with Pulse-Width Pulse-Frequency Modulation Using Observer-based Modified PID Controller. Modares Mechanical Engineering 2016; 16 (8) :139-148
URL:
http://mme.modares.ac.ir/article-15-1094-en.html
Abstract: (6396 Views)
In this paper, the performance of a single-axis attitude control with pulse-width pulse-frequency (PWPF) modulation is enhanced using a modified proportional-integral-derivative (PID) controller for a rigid satellite with on-off thruster actuators. For this purpose, the well-known observer-based PID approach is utilized. The on-off thruster actuator is modeled with a constant delay followed by a second-order binomial transfer function. The modulator update frequency is limited to 40 Hz as an input to the on-off thruster actuators. In this study, the design criteria of pointing accuracy, overshoot of the attitude response, fuel consumption, and the number of thruster firings are considered for a step external disturbance (with different values). The parameters of the observer-based PID controller are tuned using parametric search method. Simulation results show that the fuel consumption and settling time of the observer-based approach are considerably decreased with respect to those of PID controller with PWPF modulator. Moreover, the overshoot of the observer-based approach is omitted. Finally, the robustness of the observer-based modified PID controller is investigated in presence of uncertainties in satellite moment of inertia and thrust level of on-off actuators.
Article Type:
Research Article |
Subject:
Control Received: 2016/06/2 | Accepted: 2016/07/4 | Published: 2016/08/14