On attitude controller design for Mars quadcopter: Parameter identification and hovering experiment

Based on the joint exploration of Mars by various exploration spacecraft, the latest Mars spacecraft changes from rovers to rotorcraft. The landmark event is the successful flight of the “Ingenuity” Mars helicopter, which not only proves the feasibility of Mars rotorcraft, but also provides a new avenue for Mars exploration. In the past, researchers mainly focus on the feasibility of the Mars rotorcraft concept, with less research on attitude control. In addition, the low atmospheric density and low gravity of Mars pose challenges to the attitude control of rotorcraft. Therefore, this paper studies the design of the attitude controller for a Mars quadcopter, which weighs 3.9 kg and has four two-bladed rotors with a diameter of 0.9 m. First, the parameters within the flight control model in the Martian environment are jointly identified through experimentation and simulation. Then, an attitude controller is designed based on the model and verified through semi-physical simulation. Finally, the hovering flight demonstration test is carried out in the Mars Atmospheric Simulator equipment. During the test, the fluctuation ranges of roll angle, pitch angle, and yaw angle in the hovering state are ±2°, ±2°, and −3.8°∼2.4°, respectively, which verify the effectiveness of the attitude controller. This paper provides theoretical and practical references for the design and application of future Mars quadcopters.