Automation, Control and Intelligent Systems 2019; 4(1): 39-45 http://www.sciencepublishinggroup.com/j/acis doi: 10.11648/j.acis.20190701.15 ISSN: 2328-5583 (Print); ISSN: 2328-5591 (Online) System Modeling and Controller Design for Lateral and Longitudinal Motion of F-16 Waqas Ahmed * , Zhongjian Li, Hamid Maqsood, Bilal Anwar School of Automation, Northwestern Polytechnical University, Xi’an, China Email address: * Corresponding author To cite this article: Waqas Ahmed, Zhongjian Li, Hamid Maqsood, Bilal Anwar. System Modeling and Controller Design for Lateral and Longitudinal Motion of F-16. Automation, Control and Intelligent Systems. Vol. 7, No. 1, 2019, pp. 39-45. doi: 10.11648/j.acis.20190701.15 Received: April 15, 2019; Accepted: May 28, 2019; Published: June 15, 2019 Abstract: Classical control laws are still widely used in aviation industry because of their good structural understanding, simplicity, and better tracking control performance. However in recent decades the application of such controllers are getting substantial interest of researchers. This paper addresses controller design method for longitudinal and lateral motion autopilots of F-16. Aircraft complete mathematical model was obtained using Newton-Euler formulism. The non-linear model was linearized around equilibrium points at certain trim conditions to obtain state space model of the system. Comparative analysis of two linear controllers, Proportional-Integral-Derivative (PID) and Linear-Quadratic-Regulator (LQR) is investigated and control algorithm is proposed. Both the control schemes use feedback control laws and a careful selection of tuning parameters for controllers is carried out to track the desired input reference. Effectiveness of both controllers is illustrated with the help Matlab/Simulink figures and results. Keywords: Aircraft Modeling, Autopilots, PID, LQR 1. Introduction Wright brother’s had the honor to make the first flight in aviation history. Following that aviation industry had some dramatic development and the pace with which these changes happened was quite astonishing [1]. The Stability and Control of the airplanes was always a key issue from the very beginning of the aeronautical industry. The introduction of autopilots was one of the great step in aviation development. Initially the autopilots were used with the purpose to replace the human pilot during cruise modes. They were expected to perform more rapidly and with greater precision as compare to the human pilot and to fly aircraft in the same manner as a well-trained pilot. Around 1912 Sperry Gyroscope Company designed and developed an autopilot which was used on a flying boat for a trial. By 1914 the progress reached such a state of development that a public flying demonstration was given [2]. When an aircraft had a deviation form a particular flight path, the autopilots alter the roll, pitch and heading angles of an aircraft. The Automatic Flight Control System (AFSC) concept was changed from mechanically control aircraft to fly by wire control system. In recent decades AFCS is utilized to assist pilot in controlling the aircraft and also help in simultaneously sensors, navigation, guidance and flight instrument display [3]. General aircraft have a six-degree-of-freedom motion, which is further split into translational (horizontal, vertical and transverse) and rotational (pitch, roll and yaw) motions. Aircraft have three control surfaces (Rudder, Elevator and ailerons) which provides help in rotational motion of the aircraft. The lateral axis travel from wingtip-to-wingtip and the pitch motion is angular displacement about this axis while longitudinal axis passes through aircraft from nose-to-tail and motion about this axis is called roll motion. Pitch control can be achieved by providing change to elevator surface. Similarly Roll motion can be controlled with the help of ailerons while for yaw control we need to have a change in rudder surface [4]. In recent decades, enormous techniques including linear and non-linear approaches are investigated to propose control schemes for F-16 [5-7]. It has been stated that LQR controller to be the best for pitch control of aircraft system compared with linear feedback control in [8]. Aircraft Roll Control System Using LQR and PID was done in [9].