In this paper, the target-tracking problem of a 3-axis camera gimbal mounted on a flying vehicle is considered. In order to keep the camera’s line of sight continuously pointing to a moving target, an optimal controller using LQR control techniques is applied. The motion equations of the gimbal system are derived by the Lagrangian approach considering the vehicle motion. | Journal of Science & Technology 127 (2018) 035-039 Optimal Control for the Target-Tracking Problem using Three-Axis Camera Gimbals Do Dang Khoa*, Le Quang Duong Hanoi University of Science and Technology, No. 1, Dai Co Viet, Hai Ba Trung, Hanoi, Viet Nam Received: November 12, 2017; Accepted: June 25, 2018 Abstract In this paper, the target-tracking problem of a 3-axis camera gimbal mounted on a flying vehicle is considered. In order to keep the camera’s line of sight continuously pointing to a moving target, an optimal controller using LQR control techniques is applied. The motion equations of the gimbal system are derived by the Lagrangian approach considering the vehicle motion. The LQR controller is designed based on the system’s continuously linearized model. A tuning method for the LQR is also proposed to make the gimbal system point to a moving target in the shortest time. The feasibility of the proposed controller is shown by numerical simulations. Keywords: Optimal Control, LQR, Camera Gimbal, Line of Sight (LOS) the Lagrangian approach under the flying platform’s inertial effects and a linear quadratic regulator (LQR) is utilized. An offline-tuning procedure for LQR is proposed to find optimal values of state and control weight matrices to improve gimbal target-tracking performance. 1. Introduction* Inertial stabilized platforms (ISPs) are mechanisms to control and stabilize the LOS of optical equipment. Recently, ISPs have been popularized in many civil and commercial applications (. movies shootings, aerial photography). In such systems, the optical equipment, which is often mounted on a moving vehicle, must keep its optical sensor’s LOS pointing to a fixed or moving target. One of the most common types of ISPs is based on a gimballed structure [1]. The two main issues are raised as to build exact physical models and to develop good control algorithm to fulfill the target-tracking problems. Basically, there are two approaches to derive the gimbal
