Gun-Hee Moon

Study on payload stabilization method with the slung-load transportation system using a quad-rotor

This paper introduces the payload stabilization method for safe payload transportation. We assumed that the vehicle and the payload are connected by wires, which is called the slung-load system. For the slung-load system, the wire generates various constraint forces between the vehicle and the payload. Various types of slung-load systems can be defined by various numbers of vehicles and payloads, but in this research, we used the slung-load system that is composed of only one vehicle and one payload. To model the slung-load system, we applied the Udwadia-Kalaba equation (UKE) to account for the slung-load system with various constraint forces. To transport the payload safely to destination point from the starting point, we suggest the payload stabilization method that modifies the structure of position controller of a quad-rotor. Controller gain design processes are also performed. Lastly, using the derived system model based on the UKE, simulation and flight tests are performed to demonstrate the performance of the payload stabilization method we suggested. Additionally, a particular unmanned aerial vehicle of quad-rotor is chosen as the main platforms of the entire system due to its advantages such as simple control logic implementation and maintainability.

Quaternion based attitude control and suboptimal rendezvous guidance on satellite proximity operation

This paper introduces a suboptimal rendezvous guidance method and a quaternion based attitude control law for satellite proximity operation. A dynamic model of relative motion between two satellites is expressed as a linear dynamic model, called the Clohessy-Wiltshire equation, while the satellites attitude is governed by the rigid body kinematic. A solution of a linear quadratic control problem is obtainable with a system of algebraic equations. This paper proposes a suboptimal rendezvous guidance law based on the LQC and a quaternion based attitude controller to comply the suboptimal command. Several cases of simulation is conducted to prove that proposed method can meet the terminal condition on the desired time, and attitude control logic is well functioning to comply the guidance command.

Distributed Task Assignment Algorithm for SEAD Mission of Heterogeneous UAVs Based on CBBA Algorithm

This paper presents a distributed task assignment algorithm for the suppression of enemy air defense (SEAD) mission of heterogeneous UAVs, based on the consensus-based bundle algorithm (CBBA). SEAD mission can be modeled as a task assignment problem of multiple UAVs performing multiple air defense targets, and UAVs performing SEAD mission consist of the weasel for destruction of enemy`s air defense system and the striker for the battle damage assessment (BDA) or other tasks. In this paper, a distributed task assignment algorithm considering path-planning in presence of terrain obstacle is developed for heterogeneous UAVs, and then it is applied to SEAD mission. Through numerical simulations the performance and the applicability of the proposed method are tested.