• Journal of the Korea Institute of Military Science and Technology
• /
• v.16 no.2
• /
• pp.95-100
• /
• 2013

Localization is very important for the autonomous navigation of Unmanned Ground Vehicles; however, it is difficult that they have a precise Inertial Navigation System(INS) sensor, especially Small Unmanned Ground Vehicle(SUGV). Moreover, there are some condition such as denial of global position system(GPS), GPS/INS integrated system is not robust. This paper proposes the estimation algorithm with optical flow sensor and INS. Being compared with previous researches, the proposed algorithm is suitable for skid steering vehicles. We revised the measurement model of previous research for the accuracy of side direction position. Experimental results were performed to verify the algorithm, and the result showed an excellent performance.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.20 no.6
• /
• pp.803-812
• /
• 2017

This paper proposes a local path planning method for stable autonomous driving in rough terrain. There are various path planning techniques such as candidate paths, star algorithm, and Rapidly-exploring Random Tree algorithms. However, such existing path planning has limitations to reflecting the stability of unmanned ground vehicles. This paper suggest a path planning algorithm that considering the stability of unmanned ground vehicles. The algorithm is based on the genetic algorithm and assumes to have probability based obstacle map and elevation map. The simulation result show that the proposed algorithm can be used for real-time local path planning in rough terrain.

• International Journal of Computer Science & Network Security
• /
• v.21 no.3
• /
• pp.145-152
• /
• 2021

In the Recent times, various technological enhancements in the field of artificial intelligence and big data has been noticed. This advancement coupled with the evolution of the 5G communication and Internet of Things technologies, has helped in the development in the domain of smart mine construction. The development of unmanned vehicles with enhanced and smart scheduling system for open-pit mine transportation is one such much needed application. Traditional open-pit mining systems, which often cause vehicle delays and congestion, are controlled by human authority. The number of sensors has been used to operate unmanned cars in an open-pit mine. The sensors haves been used to prove the real-time data in large quantity. Using this data, we analyses and create an improved transportation scheduling mechanism so as to optimize the paths for the vehicles. Considering the huge amount the data received and aggregated through various sensors or sources like, the GPS data of the unmanned vehicle, the equipment information, an intelligent, and multi-target, open-pit mine unmanned vehicle schedules model was developed. It is also matched with real open-pit mine product to reduce transport costs, overall unmanned vehicle wait times and fluctuation in ore quality. To resolve the issue of scheduling the transportation, we prefer to use algorithms based on artificial intelligence. To improve the convergence, distribution, and diversity of the classic, rapidly non-dominated genetic trial algorithm, to solve limited high-dimensional multi-objective problems, we propose a decomposition-based restricted genetic algorithm for dominance (DBCDP-NSGA-II).

• Journal of Sensor Science and Technology
• /
• v.33 no.5
• /
• pp.391-398
• /
• 2024

Accurate positioning is essential for unmanned underwater vehicle (UUV) operations, particularly for long-term survey missions. To reduce the inherent positioning errors from the inertial navigation systems of UUVs, or dead reckoning, underwater terrain observations from sonar sensors are typically exploited. Within the framework of pose-graph optimization, we can generate submaps of the seafloor and use them to add loop-closure constraints to the pose graph by determining the best match between the submaps. However, this approach results in error accumulation in long-term operations because the quality of local submaps depends on the dead reckoning. Hence, we can adopt external acoustic positioning systems, such as an ultrashort baseline (USBL), to add global constraints to the existing pose graph. We assume that the acoustic transponder is installed on a UUV and that the acoustic transceiver is equipped in an unmanned surface vehicle trailing the UUV to maintain an acoustic connection between the vehicles. We simulate the terrain and USBL measurements as well as evaluate the performance of the UUV's pose estimation via online pose-graph optimization.

• Journal of Power System Engineering
• /
• v.16 no.1
• /
• pp.84-90
• /
• 2012

In unmanned vehicles' navigation, the shapes of obstacles are generally irregular and complex. The motion of vehicles based on the range sensor system such as ultrasonic sensors or laser sensors can be unstable due to the irregular shape of the obstacles. In this case, to generate stable trajectory of unmanned vehicles equipped with range sensors, we need an approach that can simplify an obstacle's irregular shape information. In this paper, we propose the trajectory generation algorithm that an vehicle can stably navigate in the environments where irregular shaped obstacles are scattered. The proposed method is verified through the analysis of vehicle's trail and direction data acquired by simulations and implementations.

• Journal of Institute of Control, Robotics and Systems
• /
• v.14 no.12
• /
• pp.1212-1217
• /
• 2008

This paper studies the feasibility of using the nonlinear model predictive control as a formation flight control algorithm for unmanned aerial vehicles. The optimal control inputs for formation flight are calculated through the cost function which incorporates the relative positions of the individual vehicles to maintain a desired formation and also the inequality constraints on inputs and states using the Karush-Kuhn-Tucker conditions. In the nonlinear model predictive control setting, the optimal control inputs are implemented in a receding horizon manner, which is suitable for dealing with dynamic constraints. Numerical simulations are executed for the validation of the proposed scheme.

• The Journal of Korea Robotics Society
• /
• v.17 no.4
• /
• pp.477-483
• /
• 2022

In this paper, we propose waste collection vehicle system with a safety device for worker safety and an autonomous driving function. The steering system is applied as MDPS (Motor Drive Power Steering) system to control the waste collection vehicle of the internal combustion engine. Safety-related errors is prevented through redundancy brake of the integrated system and the control braking system. In order to ensure safety between workers and waste collection vehicles, work guidelines and safety devices for emergency stop in case of danger are applied to vehicles. In addition, this research is conducted on improving the working efficiency through vehicle condition monitoring system and a short-range control system for field test. This research is aimed to secure stability through demonstration and contribute to the industrialization of unmanned waste collection vehicles.

• Journal of Electrical Engineering and Technology
• /
• v.13 no.1
• /
• pp.493-500
• /
• 2018

This paper addresses a decentralized observer-based output-feedback formation control problem for multiple unmanned underwater vehicles (UUVs). The complex nonlinear model for a UUV is feedback-linearized. It is assumed that each UUV in the formation exploits only the information regarding itself and the immediate predecessor, which imposes structural constraints on the formation controller gain matrices. The design condition is presented as a two-stage linear matrix inequalities problem. The synthesized controller demonstrates its own advantages through a numerical example.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.23 no.6
• /
• pp.618-638
• /
• 2020

An unmanned aerial vehicle(UAV) refers to an aircraft that has all or part of its functions to autonomously fly by grasping the surrounding environment by remote control on the ground without a pilot on board. With the development of unmanned aerial technology, civil/military forces are developing unmanned aerial vehicles for various purposes. In order to control unmanned aerial vehicles from the ground, communication protocols between unmanned aerial vehicles and ground control equipment are required, and civil/military forces have developed and used a photocall for different purposes. In this study, the characteristics of the MAVLink protocol used in the private sector and the STANAG 4586 protocol used in the military are compared/analyzed in detail to find elements to complement each other and to draw improvement measures for protocol unification.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.22 no.5
• /
• pp.597-602
• /
• 2012

In this paper, a manual and automatic steering system for electric vehicles capable of manned and unmanned driving is proposed. The automatic steering systems, EPS, MDPS, used in conventional engine based car includes the problem of handle lock phenomenon while driving of overloading, therefore it has a drawback to apply to manned and unmanned electric vehicles. By using electronic clutch and pulleys, the proposed manual and automatic steering mechanism was designed so that it is possible to convert from manual to automatic steering mode. To experiment the performance of the proposed steering system, we made an experimental setup of an electric vehicle. We confirmed that the proposed manual and automatic steering system was useful for manned and unmanned electric vehicles.