• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.42 no.2
• /
• pp.424-431
• /
• 2017

These days land vehicle navigation system is a subject of great interest. The GNSS(Global Navigation Satellite System) is the most popular technology for out door positioning. However, The GNSS is incapable of providing high accuracy and reliable positioning. For that reason, we applied Network-RTK in vehicle to improve the accuracy of GNSS performance. In this network-RTK mode, the GNSS error are significantly decreased. In this paper, we explain ntrip client program for network-RTK mode and show the result of experiments in various environments.

• Journal of Positioning, Navigation, and Timing
• /
• v.11 no.3
• /
• pp.199-208
• /
• 2022

Inertial Navigation System (INS)/Global Navigation Satellite System (GNSS) integrated navigation system can be used for land vehicle navigation. When the GNSS signal is blocked in a dense urban area or tunnel, however, the problem of increasing the error over time is unavoidable because navigation must be performed only with the INS. In this paper, Non-Holonomic Constraints (NHC) information is utilized to solve this problem. The NHC may correct some of the errors of the INS. However, it should be noted that NHC information is not applicable to all areas within the vehicle. In other words, the lever arm effect occurs according to the distance between the Inertial Measurement Unit (IMU) mounting position and the NHC effective point, which causes the NHC condition not to be satisfied at the IMU mounting position. In this paper, an INS/GNSS/NHC integrated navigation filter is designed, and this filter has a function to compensate for the lever arm effect. Therefore, NHC information can be safely used regardless of the vehicle's driving environment. The performance of the proposed technology is verified through Monte-Carlo simulation, and the performance is confirmed through experimental test.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2015.10a
• /
• pp.73-74
• /
• 2015

In the world the interests about a unmanned surface vehicle(USV) are growing up. However it is difficult to launch and recover a USV because of no men on board of USV. And it is more difficult in recovery than launch of USV. So in this research the heaving line launcher was developed to support the recovery of USV easier. And a mock-up was manufactured to validate for adoption to the USV. The muck-up is composed of launcher pipe, remote trigger, air tank, tow shell and heaving line. Tests in land using the mock-up were carried out. The forces by the heaving line launcher to USV were measured by a measuring table during the tests in land. In this paper the development of a mock-up of heaving line launcher, tests in land and the measured forces during tests are presented.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.11 no.2
• /
• pp.66-72
• /
• 2008

A distributed missile system is composed of command control center, radar and launcher which exchange information each other to use wire or wireless network. The distributed missile system is required mobility for operational convenience and survivability. Also missile system requests land navigation system to provide relatively accurate attitude. For reason of these requirements, each subsystem needs land navigation which provides information of position and attitude. This paper represents operational concept for land navigation to consider operational environment and concrete operational procedure to apply the operational concept. In state that there is no operation for land navigation of distributed missile system internally so for, this paper could be helped to establish operational concept and procedure of this kind of system.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.6
• /
• pp.689-695
• /
• 2018

This paper presents the means of controlling the regeneration of a diesel particulate filter (DPF) that is mounted on tactical vehicles to satisfy exhaust gas standards. The DPF captures particulate matter in the exhaust gas and combusts the captured particulate matter. This process is regeneration, which is essential to the normal performance of the DPF. Bad regeneration causes degradation of vehicle performance; worse, it can lead to a vehicle fire. DPF regeneration is performed by control logic. If the regeneration control logic does not properly reflect the operating characteristics of the vehicle, DPF regeneration may not occur. Consequently, it is very important to ensure the DPF operates properly by reflecting the operating characteristics of the tactical vehicle. This study analyzes the operational characteristics of a tactical vehicle and the DPF, and adds proper DPF regeneration control logic. Additionally, this study is intended to simultaneously improve the additional problems that may occur from operating under the added regeneration control logic.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.49 no.1
• /
• pp.64-73
• /
• 2012

In this paper, a new land preview system using laser range finder based on heave estimation algorithm is proposed. The proposed land preview system is an equipment which measures the shape of forward topography for autonomous vehicle. To implement this land preview system, the laser range finder is generally used because of its wide measuring range and robustness under various environmental condition. Then the current location of the vehicle has to be known to generate the shape of forward topography and sensors based on acceleration such as IMU and accelerometer are generally utilized to measure heave motion in the conventional land preview system. However the drawback to these sensors is that they are too expensive for low-cost vehicle such as mobile robot and their measurement error is increased for mobile robot with abrupt acceleration. In order to overcome this drawback, an algorithm that estimates heave motion using the information of odometer and previously measured topography is proposed in this paper. The proposed land preview system based on the heave estimation algorithm is verified through simulation and experiments for various terrain using a simulator and a real system.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.2
• /
• pp.763-772
• /
• 2019

Recently, there is a great expectation for the sustainable effect of TOD and apply it to urban planning and design. However, there are few research on the quantitative evaluation method of the effect. The purpose of this study is to propose a quantitative way to assess the effectiveness of TOD(Transit Oriented Development)'s vehicle traffic reduction in the urban planning phase, based on the land-use plan. Firstly, it proposes a method to convert the information contained in the land-use plan into a network and secondly a method to estimate the travel distance based on the network. In the first phase, the roads in the land-use plan are converted into links and the intersection of the roads into nodes. The area and the height of the zones included in the land-use plan are converted into the weights on adjacent nodes. The second phase assumes the frequency at which travel occurs between nodes on the network is relative to the weights and estimates the travel distance by dividing it into a pedestrian and a vehicle. Then, taking the city without TOD as the object, through comparison present city and alternatively redesigned city to the analysis of TOD effect. In this study, the application of these methods to Bundang as of 1997 and alternatively redesigned Bundang showed that about 39.94 percent of the vehicle traffic reduction effects occurred. Furthermore, the pedestrian traffic ratio of alternatively redesigned Bundang increased to 2.39%.

• Geophysics and Geophysical Exploration
• /
• v.7 no.1
• /
• pp.1-6
• /
• 2004

High-resolution S-wave reflection surveying has been successfully conducted on paved areas using a Land Streamer originally designed by the author. The main feature of the Land Streamer tool is the non-stretch woven belt on which geophone units are mounted to form a multichannel geophone array similar to a marine streamer. Because it is easily towed by a vehicle or by hand, the tool leads to high performance in field measurements and resultant cost-effectiveness of high-resolution reflection surveys. Although each geophone unit is coupled to the pavement through a metallic baseplate instead of being firmly planted in the ground, the Land Streamer tool provides comparatively clean data, unaffected by traffic noise even on the pavement. Thus, the tool is capable of expanding the opportunity for S-wave reflection surveys in urban areas where many surfaces are paved and traffic noise is severe. A series of high-resolution S-wave reflection surveys on paved areas delineated detailed structures of surface layers shallower than 60 m, and proved the wide applicability of the tool to engineering, environmental applications, and earthquake disaster prevention projects.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.6
• /
• pp.266-274
• /
• 2020

This paper reports a means of improving the abnormal noise of light tactical vehicles (LTVs) by applying a vehicle fitting type generator (hereinafter called generator). LTVs are classified as having generators, and there are no differences in the noise level. On the other hand, quality improvement was performed in response to unpleasant noise felt by the user (hereinafter called abnormal noise) during vehicle operation. To improve the quality, the generator mounting structure and the phenomenon of the vehicle in the problem were identified. Through this, it was confirmed that the noise caused by the generator installation was the rattle noise. Rattle noise at the engine driving system is normally caused by the transfer of irregular torque generated by the engine power stroke and the backlash by the spline-serration fitting structure between the engine coupler and rotor assembly in a generator. Therefore, this study established an improvement plan to apply a damper coupler to solve the cause of the abnormal noise. Regarding the improved establishment method, the improvement effect was confirmed from the influence of the irregular torque of the engine, noise level, dynamic characteristics analysis, and the endurance test of the parts.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.6
• /
• pp.86-94
• /
• 2019

This paper describes the development of unmanned vehicle remote control system which is configured with steering and accelerating/braking hardware to improve the sense of reality and safety of control. Generally, in these case of the remote control system, a joystick-type device is used for steering and accelerating/braking control of unmanned vehicle in most cases. Other systems have been developing using simple steering wheel, but there is no function of that feedback the feeling of driving situation to users and it mostly doesn't include the accelerating/braking control hardware. The technology of feedback means that a reproducing the feeling of current driving situation through steering and accelerating/braking hardware when driving a vehicle in person. In addition to studying feedback technologies that reduce unfamiliarity in remote control of unmanned vehicles, it is necessary to develop the remote control system with hardware that can improve sense of reality. Therefore, in this study, the reliable remote control system is developed and required system specification is defined for applying force-feedback haptic control technology developed through previous research. The system consists of a steering-wheel module similar to a normal vehicle and an accelerating/braking pedal module with actuators to operate by feedback commands. In addition, the software environment configured by CAN communication to send feedback commands to each modules. To verify the reliability of the remote control system, the force-feedback haptic control algorithms developed through previous research were applied, to assess the behavior of the algorithms in each situation.