Direction-cosine-matrix-based attitude control subject to actuator saturation

• Published in: IET control theory & applications Vol. 9; no. 11; pp. 1653 - 1661
• Main Author: Forbes, James Richard
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 16.07.2015
• Subjects: actuator saturation; Actuators; aerospace robotics; Angular velocity; angular velocity control; angular velocity control term; Attitude control; closed loop systems; closed‐loop system; control nonlinearities; control system synthesis; controller synthesis methods; Controllers; DCM; direction‐cosine‐matrix parameterisation; direction‐cosine‐matrix‐based attitude control; Euler angles; feedback; feedback control algorithm; input nonlinearity; Kalman–Yakubovich–Popov lemma; linear quadratic control; linear quadratic regulator problem; linearisation techniques; linearised system; Low pass filters; low‐pass filter; Mathematical models; matrix algebra; on‐board actuators; plant disturbances; proportional control; quaternions; rigid body; Rigid-body dynamics; Saturation; sensor noise; set‐point attitude control; quaternions; linear quadratic regulator problem; Euler angles; controller synthesis methods; angular velocity control; linearised system; proportional control; angular velocity control term; feedback; feedback control algorithm; rigid body; control nonlinearities; direction-cosine-matrix parameterisation; attitude control; low-pass filters; actuator saturation; low-pass filter; set-point attitude control; linearisation techniques; Kalman–Yakubovich–Popov lemma; on-board actuators; control system synthesis; plant disturbances; aerospace robotics; sensor noise; matrix algebra; DCM; closed loop systems; input nonlinearity; direction-cosine-matrix-based attitude control; closed-loop system; linear quadratic control
• ISSN: 1751-8644; 1751-8652
• DOI: 10.1049/iet-cta.2014.0890

Set-point attitude control of a rigid body explicitly preventing actuator saturation is considered. The attitude control approach developed does not employ any sort of direction-cosine-matrix (DCM) parameterisation, such as Euler angles or quaternions. Rather, the DCM is used directly within the feedback control algorithm. Together a proportional control term and an angular velocity control term make up the attitude controller. The angular velocity control is composed of a strictly positive real system subject to a special input non-linearity. The specific form of the proportional control and angular velocity control ensure control torques are below the saturation level of the on-board actuators. Two controller synthesis methods are considered. The first uses the linearised system, the solution to the linear quadratic regulator problem, and the Kalman–Yakubovich–Popov lemma to design the controller. The second employs a simple low-pass filter that is guaranteed to stabilise the closed-loop system; tuning the low-pass filter is also considered. Numerical simulation results demonstrate effective closed-loop control in the presence of plant disturbances and sensor noise.