Overloaded and improperly loaded trucks cause serious road hazards, such as rollovers and cargo falls. Although automatic enforcement methods are being studied, they face challenges in accuracy and legal application. Thus, a technology for direct tracking and enforcement is needed. This study uses EfficientNet to extract features of vehicles and license plates, and applies cosine similarity to identify the same vehicle. Comparisons were divided into “same vehicle” and “similar vehicle,” with a threshold-based method and five classification types. Results showed that the average similarity of the same vehicle group was 0.11 higher than that of the similar vehicle group. The accuracy of correctly identifying the same vehicle was 84.54%. Integrating OCR or LPR is expected to further improve tracking performance.
Aerial work platforms (AWPs) are specialized vehicles designed for tasks at elevated heights, and are widely used in various environments such as construction sites, road maintenance, and high-altitude operations. In this study, computational fluid dynamics (CFD) analysis was conducted to investigate the airflow field, drag force, and torque characteristics around an AWP. The simulation results showed that the overall airflow velocity decreased as it passed over the vehicle and boom, while it increased locally between the vehicle and the boom, and beneath the work platform. The drag force and torque acting on each component were highly sensitive to changes in boom angle due to variations in airflow. As the boom angle increased, the drag force increased by approximately 20 times, and the torque by up to 108 times. These findings provide fundamental data for establishing design criteria to enhance the structural stability and aerodynamic performance of aerial work platforms.
This study aims to present a methodology and the corresponding results of an economic analysis, incorporating both costs and benefits, to assess the feasibility of introducing a smart on-board truck scale.The cost estimation was conducted based on direct expenditures associated with the installation and operation of smart on-board truck scales. The benefit analysis was performed by evaluating the reduction in social costs resulting from the mitigation of overloading, including transportation infrastructure maintenance costs, traffic accident costs, and environmental costs. The economic analysis outlines the variables required for each phase of the smart on-board truck scale implementation, along with their reasonable value ranges. In consideration of the uncertainty regarding the effectiveness of the smart on-board truck scales, a quantitative assessment of the impact of individual variables on the economic indicators was carried out through scenario analysis, focusing on key variables. The influence of the vehicle service life, the service life of the smart on-board truck scale, and personnel expenses—each related to installation and operation—on the benefit-cost ratio (B/C) and net present value (NPV) was determined to be limited. In contrast, the overload crackdown rate exhibited the most significant impact on the B/C and NPV, as it directly increased the number of vehicles contributing to measurable benefits. Notably, an increase in the discount rate led to a decrease in the values of both economic indicators. This outcome is expected, as the discount rate reduces the present value of future costs and benefits by increasing the denominator in the calculation. The introduction of smart on-board truck scales enables the achievement of economic feasibility in preemptive overload enforcement. Therefore, progressively expanding the number of vehicles equipped with smart on-board truck scales is essential to maximize their effectiveness in the near term.
In this study, a layout was designed to adjust the location of the LPG fuel tank by combining a Z-Spring and an Airbag in an LPG 1-ton truck air suspension assembly, and a structural analysis based on the finite element method was performed considering the load conditions of extreme situations based on the weight taken into account. The study was performed under a total load condition of 2.1 tons per axle with a safety factor of 2, and it was confirmed that the maximum stress value occurring in each part is within the yield strength value of the material. Through these results, it was confirmed that the designed LPG 1-ton truck air suspension assembly is a system with secured structural stability.
Recently, corrosion problems caused by quarantine disinfectant have occurred in the door panel of commercial trucks. As a way to solve this problem, a drain hole is being drilled in the door panel, and the door panel is being designed again for this purpose. Reinforcing parts such as frames or brackets for rigidity are attached to the inner and outer door panels, and spot welding is performed for assembly. X-rays and nugget diameter measurements of the welds were performed to confirm the results of performing according to various conditions for such spot welding. Through this study, it was confirmed that the pressing force had a greater effect on the welding quality than the amount of welding current.
Aerial work platform truck is used in various ways depending on the surrounding environment, of city roads, farming areas, and industrial sites. Air flow, drag force and torque in surroundig the flow field of AWP have been analyzed with CFD method. The overall air flow rate decreases as the AWP passes and increases between the vehicle and the boom, at the boom connections, and at the bottom of the work platform. The drag force and torque on the boom, workspace, and the combined boom and workspace are largely affected by air flow velocity. The boom's drag and torque are approximately 2.2 and 1.3 times greater than those of the work platform, respectively. These predicted results can be widely applied as basic conceptual design data for highly efficient aerial work platform truck.
초대형 자동차운반선(LCTC)의 높이는 선저에서 조타실까지 약 44~46m에 이르며, 자동차운반선이 대형화될수록 상부 무게가 하부 무게보다 무거운 중두선의 특징을 가진다. 이 연구는 선회 중 전도한 자동차운반선 골든 레이호(G호)의 최대 외방경사각을 추정하 여 사고 원인 규명과 유사사고 방지에 목적이 있다. 이론식으로 계산된 최대 외방경사각은 GM이 +3.0m 이상 상황에서 7.5°(19kn, 타각 35°), GM이 +1.85m인 상황에서 16.7°였다. 실험에 의한 수정식으로 계산한 최대 외방경사각은 GM이 +3.0m 이상 상황에서 10.5°(19kn, 타각 35°), GM이 +1.85m인 상황에서 23.3°를 보였다. G호는 전도사고 당시 도선사의 지시에 따라 속력 13kn, 우현 타각(10°→20°)을 사용하여 침 로 038°(T)에서 105°(T)로 변침 중이었다. 이 때 최대 외방경사각은 좌현으로 7.8° 내지 10.9°로 추정된다. 평상 시 외방경사각보다 2.2배 높 은 수치이다. 화물선의 최소 GoM은 IS coded에서 +0.15m 이상을 요구하고 있다. 전도된 G호도 +1.72m GoM을 확보하고 있었다. GoM에 대 한 기준 미달이 전도의 원인이 아니라, 선회 중 횡경사 모멘트에 대응할 수 있는 충분한 GoM을 확보하지 않아 전도된 것이다. 이 연구는 중앙해양안전심판원과 USCG의 사고 조사 결과를 뒷받침한다.
Truck no-show behavior has posed significant disruptions to the planning and execution of port operations. By delving into the key factors that contribute to truck appointment no-shows and proactively predicting such behavior, it becomes possible to make preemptive adjustments to port operation plans, thereby enhancing overall operational efficiency. Considering the data imbalance and the impact of accuracy for each decision tree on the performance of the random forest model, a model based on the Borderline Synthetic Minority Over-Sampling Technique and Weighted Random Forest (BSMOTE-WRF) is proposed to predict truck appointment no-shows and explore the relationship between truck appointment no-shows and factors such as weather conditions, appointment time slot, the number of truck appointments, and traffic conditions. In order to illustrate the effectiveness of the proposed model, the experiments were conducted with the available dataset from the Tianjin Port Second Container Terminal. It is demonstrated that the prediction accuracy of BSMOTE-WRF model is improved by 4%-5% compared with logistic regression, random forest, and support vector machines. Importance ranking of factors affecting truck no-show indicate that (1) The number of truck appointments during specific time slots have the highest impact on truck no-show behavior, and the congestion coefficient has the secondhighest impact on truck no-show behavior and its influence is also significant; (2) Compared to the number of truck appointments and congestion coefficient, the impact of severe weather on truck no-show behavior is relatively low, but it still has some influence; (3) Although the impact of appointment time slots is lower than other influencing factors, the influence of specific time slots on truck no-show behavior should not be overlooked. The BSMOTE-WRF model effectively analyzes the influencing factors and predicts truck no-show behavior in appointment-based systems.
The curb weight of electric trucks is more than 10% higher than that of conventional internal combustion engine trucks due to the motor and battery. For this reason, cargo box developed for small electric trucks is required weight reduction, and cargo door that can reduce weight and maintain strength are being developed. In this paper, we designed the lightweight cargo door, confirmed the stability of the door through structural analysis, and developed a cargo box door that was more than 25% lighter by applying composite materials such as Sheet Molding Compound(SMC) and Fiber Reinforced Plastic(FRP).
PURPOSES : Unlike European standards, domestic performance assessment standards for truck mounted attenuators (TMAs) was first stipulated in 2014 using the NCHRP Report 350 of 1993 as the standard instead of the 2009 MASH of the United States. The purpose of this study is to present an improvement in the domestic performance evaluation criteria for TMAs..
METHODS : Considering the latest TMA performance evaluation standards in the U.S. and Europe, domestic performance evaluation criteria must improve stipulations related to impact speeds, impact conditions, impact cars, and support trucks. The performance change in the TMAs according to the variation in the impact speed, impact condition, impact vehicle, and support vehicle was investigated using finite element analysis (FEA).
RESULTS : The TMA for an impact speed of 100 km/h showed a limit to the safety of the occupants of the collision vehicle and workers on the road for a collision speed of 120 km/h. The safety of the workers on the road was also not guaranteed for the collision of the remaining 73.8% of vehicles that exceeds the maximum impact car weight of 1,300 kg, the lower 26.2% of the total mass composition of domestic passenger cars. In addition, a TMA that satisfied only the conditions under which the vehicle was hit head-on to the center of the TMA did not reduce the risk of a secondary collision of the impact vehicle. Furthermore, the safety of workers on the road was not guaranteed when a travel distance of a support truck of 10 tons or more was applied to a work vehicle of less than 10 tons.
CONCLUSIONS : To improve the safety of road traffic, a performance level corresponding to an impact speed of 120 km/h was added to the domestic TMA performance evaluation standard, and the eccentricity and oblique collision conditions were mandatory. Furthermore, the maximum impact vehicle weight of 1300 kg was raised to 2000 kg, and the test requester had to present support trucks of lower and upper weights such that TMA mounting trucks of various weights could be used.
In this study, in order to review the structural stability of a Sub-frame assembly mounted on a 5-ton dump truck with a telescopic cylinder type that can secure price competitiveness through cost reduction effect and an extended loading box that satisfies automobile safety standards, the 3D shape design technique for a main component parts is presented. In addition, structural analysis based on the finite element method is performed with the load condition applied to a safety factor 3.0 and boundary condition assigned to the lower part of the Sub-frame. By comparing and examining the maximum stress result from the structural analysis of the entire Sub-frame assembly and individual component and a yield strength of each material applied to each component, a design technique that can assure the structural stability of the Sub-frame assembly is presented.
Companies are making design changes by improving product quality and function to succeed while meeting customer requirements continuously. Design changes are changing the product BOM's amount, item, specification, and shape while causing a change in the product's structure. At this time, the problem of inventory exhaustion of parts before design change is a big topic. If the inventory exhaustion fails, the pieces before the design change become unused and are discarded, resulting in a decrease in asset value, and the quality cost of the design change affects the company's profits. Therefore, it is necessary to decide to minimize quality costs while minimizing waste inventory costs at the time of application of design changes. According to the analysis, priorities should be prioritized according to urgency because the quantity of items before the design change affects the applied lead time.
Many manufacturers applying third party logistics (3PLs) have some challenges to increase their logistics efficiency. This study introduces an effort to estimate the weight of the delivery trucks provided by 3PL providers, which allows the manufacturer to package and load products in trailers in advance to reduce delivery time. The accuracy of the weigh estimation is more important due to the total weight regulation. This study uses not only the data from the company but also many general prediction variables such as weather, oil prices and population of destinations. In addition, operational statistics variables are developed to indicate the availabilities of the trucks in a specific weight category for each 3PL provider. The prediction model using XGBoost regressor and permutation feature importance method provides highly acceptable performance with MAPE of 2.785% and shows the effectiveness of the developed operational statistics variables.
The lane departure warning device can not detect the lane to be driven in the future by sensing the departure of the lane passing by during driving and warning the driver. Considering the safe operation of the truck, it is also expected that the departure of the future lanes according to the dynamic weight and speed of the current truck should be predicted. This study attempted to predict whether or not to deviate from the lanes of curved roads to be driven in the future according to the current dynamic driving weight and speed in consideration of the safe driving of trucks.
In order to develop a 1 ton truck rear wheel air suspension module, this study designed and manufactured a Z-type spring and air suspension module test jig to optimize the design and reliability of the Z-type spring and vibration-free air suspension module, which are core parts, and to secure the reliability of the developed parts. We were able to achieve the technology development goal of this thesis by making a prototype and conducting a test evaluation at an external test and research institute to perform the vibration endurance test aimed in this study.
Recently, traffic accidents have continued to occur due to the failure to secure a safe distance for trucks. Unlike passenger cars, freight cars have a large fluctuation in the weight of the vehicle's shaft depending on the load, and the fatality of accidents and the possibility of accidents are high. In this study, a braking distance prediction model according to the driving speed and loading weight of a three-axis truck was implemented to prevent a forward collision accident. Learning data was generated based on simulation, and a prediction model based on machine learning was implemented to finally verify accuracy. The extra trees algorithm was selected based on the most frequently used R2 Score among regression analyses, and the accuracy of the braking distance prediction model was 98.065% through 10 random scenarios.