Vol.7 (2017) No. 3 ISSN: 2088-5334 Mathematical Modelling of Translation and Rotation Movement in Quad Tiltrotor Andi Dharmawan #* , Ahmad Ashari # , Agfianto Eko Putra #* # Department of Computer Science and Electronics, Faculty of Mathematics and Natural Science, Universitas Gadjah Mada, Yogyakarta, Indonesia E-mail: *andi_dharmawan@ugm.ac.id Abstract - Quadrotor as one type of UAV (Unmanned Aerial Vehicle) is an underactuated mechanical system. It means that the system has some control inputs is lower than its DOF (Degrees of Freedom). This condition causes quadrotor to have limited mobility because of its inherent under actuation, namely, the availability of four independent control signals (four-speed rotating propellers) versus 6 degrees of freedom parameterizing quadrotor position or orientation in space. If a quadrotor is made to have 6 DOF, a full motion control system to optimize the flight will be different from before. So it becomes necessary to develop over actuated quad tiltrotor. Quad tiltrotor has control signals more than its DOF. Therefore, we can refer it to the overactuated system. We need a good control system to fly the quad tiltrotor. Good control systems can be designed using the model of the quad tiltrotor system. We can create quad tiltrotor model using its dynamics based on Newton-Euler approach. After we have a set of model, we can simulate the control system using some control method. There are several control methods that we can use in the quad tiltrotor flight system. However, we can improve the control by implementing a modern control system that uses the concept of state space. The simulations show that the quad tiltrotor has done successful translational motion without significant interference. Also, undesirable rotation movement in the quad tiltrotor flight when performing the translational motions resulting from the transition process associated with the tilt rotor change was successfully reduced below 1 degree. Keywords: UAV; overactuated; control; state space I. INTRODUCTION UAV (Unmanned Aerial Vehicle) or UAS (Unmanned Aircraft System) is defined as a plane without a pilot sitting in it, uses aerodynamic forces to fly, either standalone (autonomous) with the help of auto pilot or piloted remotely and can carry a payload (payload) or not [1]. UAVs have been developed for a variety of purposes and missions from having the ability to perform various types of sensing missions either for civilian or military to monitor the building. The missions consist of surveillance, reconnaissance, monitoring, air patrols, high-resolution aerial photography and so forth [2]. UAV is a mechanical system that underactuated. It means a system has a lower number of actuators than degrees of freedom (DOF). In this case, the system is said to be trivially underactuated [3]. However, the design of that underactuated Quadrotor still limits the ability to fly in space that is free or irregular and also lowers the possibility of interacting with the environment by deploying the desired style-free direction. Motivated by these considerations, several solutions have been proposed in previous studies that cover different concepts, for example, the mechanism of tilt-wing [4], UAV that uses a non-parallel direction of the lift force (but fixed) [5], or implementing the tiltrotor system [6]. The possibility of combining several modules of underactuated rotorcraft to achieve full movement of the 6-DOF on a UAV is theoretically still being explored. This issue focuses on the optimal allocation of available control inputs (that may be excessive) [7]. On the contrary, the possibility of the swinging lifting force of quadrotor where the main direction of the lift force (2 DOF), which can be actively regulated may be considered [8]. Also, if the UAV made it to the movement of the full 6 DOF or more, control systems that are used to optimise the movement of UAV flight becomes different to those previously applied. One thing that needs to be optimised is the attitude control of the UAV flight. 1104