Car Trailer Research Articles

ANALYSIS OF THE CONSTRUCTION OF THE CAR TRAILER FRAME IN TERMS OF CHANGING THE ASSEMBLY TECHNOLOGY

Car trailers are quite a popular means of transport and are offered in many versions, from single axle light trailers with a maximum permissible weight of 750 kg, through two- or more-axle specialized trailers. The issues of research car trailers focus on two directions: testing the driving properties and analysing the strength of the supporting frame system. Issues related to the construction of light trailers are often common to trailers used in agriculture or general transport. In this article, based on a mass-produced car trailer, an analysis was carried out regarding the choice in the technology of making the supporting structure consisting of a lower frame and an upper frame. The term upper frame should be understood as the structure on which the lifted load box rests. The costs of materials, assembly and technological possibilities of small-scale production were taken into account. In addition, strength analyses of the numerical models were carried out for critical areas of the frame during operation. After considering the unit costs for each of the analysed assembly technologies, it was shown that riveting would be the cheapest. However, the most suitable method of assembly is welding, as it allows the use of standard profiles.

PORT AND RAILWAY CONNECTIONS AND THE HINTERLAND CONCEPT

<em>Intermodal transport began in the early twentieth century with railroad cars loaded onto carrier ships. At that time, only a few systems were available as standard freight units suitable for intermodal transport. By the middle of the twentieth century, the carriage of road vehicles, known as piggybacks, using car carrier ships or flat car trailers, became more common. Considering that that mode of transport will always play a role in the transport of containers, one can conclude that congestion problems in ports burden the infrastructure near the ports also. The deficiency of space forces ports to improve solutions for port tasks such as filling, storage, and congestion, using the new port concepts with the port entrance shifted to the interior. The increasing volume of container transport in ports has also led to a general increase in the transport volume in ports, increased the geographical coverage of the market, and significantly transferred ports into hinterlands. Ports have played a vital role not only in terms of domestic activities and the provision of exports and imports but also in other transport networks. In this study, the author emphasized the importance of hinterland logistics and proposed some solutions.</em>

Optimization of Gain Scheduled Controller for an Active Trailer Steering System Using an Evolutionary Algorithm

Car–trailer combinations can experience unstable motion modes such as trailer-sway, jackknifing and rollover that can lead to fatal accidents. These unstable motions can be mitigated with the use of an active trailer steering (ATS) system. Prior studies in ATS have leveraged the linear quadratic regulator (LQR) as an ATS controller but for many of these designs it was assumed that the vehicle and operating parameters were constant. In reality, vehicle and operating parameters may vary and have an impact on the stability of a car–trailer combination. In this paper, the weighting matrices of the LQR controller are determined using the GDE3 evolutionary optimization algorithm with the objective of addressing the design trade off between minimizing the car–trailer’s path-following performance for low vehicle speeds and minimizing the rearward amplification for high vehicle speeds. The effectiveness of the approach is demonstrated using a numerical simulation car–trailer model developed in the CarSim simulator. Our results show that the multi-objective tuned gain scheduling controller outperforms a non-tuned gain scheduling controller in terms of improving the lateral stability and the path following performance of car–trailer combinations in driver in the loop single lane-change maneuvers at a constant vehicle forward speed.

On nonlinear model predictive direct yaw moment control for trailer sway mitigation

In car–trailer combinations, the hitch angle is the relative yaw angle between towing car and trailer. The literature has shown that the inclusion of the hitch angle measurement for the feedback control of trailer oscillations can bring safety benefits, compared with conventional trailer sway mitigation algorithms based on the yaw rate of the car. Given the nonlinearity of the vehicle system in the typical conditions requiring the hitch angle control function intervention, nonlinear model-based controllers could be an effective solution. This paper presents four real-time implementable nonlinear model predictive control (NMPC) formulations, using the hitch angle measurement for the torque-vectoring (TV) control of an electric front-wheel drive car towing a trailer. The simulation results show that: (i) the active safety is enhanced by the proposed NMPC TV formulations, with respect to a benchmarking NMPC TV controller only based on the control of the towing car; (ii) the NMPC formulations that directly constrain the hitch angle error, or perform continuous hitch angle tracking, outperform those that modify the reference yaw rate or yaw rate error based on the hitch angle error; and (iii) the NMPC approaches including a dynamic model of the trailer are robust with respect to variations of trailer parameters.

Strength testing of a modular trailer with a sandwich platform

The article presents the experimental strength evaluation of modular car trailers with a maximum permissible total mass of up to 3500 kg and its application to assess the mechanical strength of box-type car trailers. Tests were carried out using an original test bench dedicated to fatigue testing. They aimed to compare a trailer made in traditional technology with a trailer equipped with a load-carrying structure containing a sandwich panel. As a result of the conducted work, the displacement values of the measurement points were measured. The deformation form of the trailer made in the traditional technology was compared with the trailer containing the sandwich panel. The proposed method of experimental strength evaluation of modular car trailers enables a quantitative assessment of the mechanical strength of the load-carrying structures of trailers. This results in improved safety of trailer operation in road traffic by identifying the critical elements of the load-carrying structure at the early design phase before the trailer is allowed to run on the road.

Експлуатаційна надійність і роботоздатність вантажного автомобільного рухомого складу

The article analyzes the causes of failures of vehicle structures belonging to complex systems. In order to ensure the operational reliability and operability of freight rolling stock, namely the supporting frames of automotive cargo semi-trailers and trailers during their operation. The chosen topic is relevant today, because the automotive industry is firmly in the lead in the transport industry. It is known that the quality of transportation is determined by the technical conditions of rolling stock. This is especially important if the rolling stock is represented by vehicles The reliability of freight rolling stock was studied, taking into account 2000 hours of experimental tests at the machine-test station during transport works, including 3.5 thousand loading and unloading cycles, which is 50% of the operating time. It is noted that the organization of transport work of the machine-test station does not exactly coincide with the real operating conditions, which affects the reliability indicators: for example, readiness and average failure time increase, and failure decreases. Structural analysis of the fault complex is an important part of a comprehensive system to ensure the reliability and survivability of the supporting frame of the car trailer. Generally speaking, the main causes of metal failures are manufacturing defects (production stage) and design errors (design stage), and the overall failure rate due to poor design and production quality can be over 50%. The analysis of the causes of failure of welded metal structures shows that the influence of a single factor on its frequency in emergency situations, factors related to stress concentration and subsequent development of cracks, is up to half. Of these, breakdowns due to design defects at the design stage and poor quality of manufacture and assembly of machines are about a quarter each, and due to low technology and low quality materials - more than a third, due to violations of vehicle rules and low quality staff - every tenth .

The method of kinematic excitation reconstruction based on measured suspension dynamic responses – experimental verification

The paper presents the method of kinematic road excitation reconstruction based on measured suspension dynamic responses and its reconstruction with use of estimated displacements of unsprung mass as a preliminary approximation of kinematic excitation and tracking control system with a PID controller that allows for faithful reconstruction of unsprung mass accelerations and, in turn, kinematic excitations. The authors performed an experimental verification of the method with use of one axle car trailer and measurements of road profile and acquiring signals of suspension dynamics responses. The signal processing methodology and obtained results are presented for random and determined excitations. The necessary requirements to use the method effectively were defined and its limitations were listed.

40Ca+ optical clocks in China

In this review, the improvements made in the past two decades for 40Ca+ optical clocks in China are presented. Uncertainty of below 1.3×10−17 was achieved by applying the “magic” RF trapping frequency and introducing a generalized Ramsey excitation scheme. The stability of 40Ca+ optical clocks has been improved to 2.5×10−15/τ with an uptime rate of 93.8% by implementing two ameliorated lock algorithms in the Ramsey excitation scheme. A long-term clock frequency comparison shows a clock stability of 6.3 × 10−18 in an averaging time of 524 000 s. A robust and transportable clock installed in an air-conditioned car trailer can achieve almost the same performance of laboratory clocks. A height difference between transportable and laboratory clocks was measured with an uncertainty of 0.33 m and the absolute frequency of 40Ca+ optical clock transitions was remeasured as 411 042 129 776 400.41(23) Hz, with a fractional uncertainty of 5.6×10−16 based on a Cs fountain clock in the National Institute of Metrology after the transportable clock was transported from Wuhan to Beijing. The author predicts that transportable single-ion optical clocks especially based on the 40Ca+ will make a significant contribution to the construction of a world-wide optical clock network and the redefinition of the unit of time in the future.

Dynamic behaviour of a car trailer

The most common causes of accidents involving trailer are poor environmental conditions, materials from which trailers are built, inappropriate assembly processes (incorrectly made welds, choosing screws or placing them so that they cannot withstand loads etc.), the inadequacy of the vehicle's speed to the runway quality, the detachment of the trailer from the towing hitch attached to the vehicle, lack of verification of the condition of the trailer (worn tires, the absence of the braking system, damaged of the resistance elements), the resonance of the trailer or the lack of attention of the drivers in traffic. The paper presents the experimental researches performed on a real trailer with one axle attached to a vehicle and driven on a road with and without obstacles. So, the influence of uncontrolled disturbing dynamic effects was analyzed based on acceleration signals recorded during test.

Geopotential measurement with a robust, transportable Ca+ optical clock

We present a robust, transportable ${\mathrm{Ca}}^{+}$ optical clock, with a systematic uncertainty of $1.3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}17}$ limited by the black-body radiation (BBR) field evaluation and an uptime rate of $g75%$ over a 20-day period. The clock is then installed in an air-conditioned car trailer, making it more convenient for applications. Referenced to a stationary laboratory clock, geopotential measurements are made with the transportable clock with a total uncertainty of 0.33 m (statistically 0.25 m and systematically 0.22 m) and agree with the spirit level measurement. After being moved $g1200$ km, the absolute frequency of the ${\mathrm{Ca}}^{+}$ optical clock transition is measured as 411 042 129 776 400.41(23) Hz, with a fractional uncertainty of $5.6\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}16}$, which is about one order of magnitude smaller than our previous measurement. The transportable built can be used for sub-meter-level elevation measurements, comparing intercontinental optical clocks, verifying basic physical theories, etc.

An overview of control schemes for improving the lateral stability of car-trailer combinations

This paper reviews the state-of-the-art control schemes for enhancing the lateral stability of car-trailer (CT) combinations. Various studies have been conducted on lateral stability control of single-unit vehicles, e.g., cars. However, much less attention has been paid to lateral stability control of multi-unit vehicles, e.g., CT, which usually exhibit poor manoeuvrability in curved-path negotiations and low lateral stability under high-speed evasive manoeuvres. The low lateral stability may lead to unstable motion modes, e.g., trailer-sway and jackknifing, causing severe accidents. To improve the lateral stability, various control schemes were designed considering relevant performance measures and evaluated using either numerical simulations or testing methods. Thus, the topics surveyed in this paper include: directional performance measures, evaluation methods, important parameters affecting the directional performance, and active control approaches for CT combinations. Important control schemes are emphasised and their features discussed and analysed. As a result of the overview, future research efforts are identified.

An overview of control schemes for improving the lateral stability of car-trailer combinations

This paper reviews the state-of-the-art control schemes for enhancing the lateral stability of car-trailer (CT) combinations. Various studies have been conducted on lateral stability control of single-unit vehicles, e.g., cars. However, much less attention has been paid to lateral stability control of multi-unit vehicles, e.g., CT, which usually exhibit poor manoeuvrability in curved-path negotiations and low lateral stability under high-speed evasive manoeuvres. The low lateral stability may lead to unstable motion modes, e.g., trailer-sway and jackknifing, causing severe accidents. To improve the lateral stability, various control schemes were designed considering relevant performance measures and evaluated using either numerical simulations or testing methods. Thus, the topics surveyed in this paper include: directional performance measures, evaluation methods, important parameters affecting the directional performance, and active control approaches for CT combinations. Important control schemes are emphasised and their features discussed and analysed. As a result of the overview, future research efforts are identified.

The Trailer as Erotic Capital. Gendered Performances—Research and Participant Roles during Festival Fieldwork

This article examines different roles and field relations of the researcher in studies of young people at Christian festivals. The main questions are how the researcher gains access to the “flirtation field,” which flirting roles the youth participants engage in, and how the researcher copes with flirtation in the field. The article’s theoretical approach draws on feminist methodology on how positions, roles, and relations are negotiated in fieldwork, and discusses the notion of erotic capital. Christian festivals in Norway attract among 100,000 people every year. One of the main activities that was brought to my attention by a car trailer was the importance of flirting between the young boys and girls at these festivals. At the Christian festivals, flirting takes place within a heterosexual framework. In order to be part of this game, the girls are supposed to be feminine and available. The boy’s role is to be active and take initiative. Both sexes work hard to become participants in this game of winning attention that represents two different worlds for boys and girls, and in which there are both male and female losers. The rules of the game seem doubly strict for the girls since they are expected to administer both their own and the boys’ lust.

Development of an autonomous energy supply system for harvesting wood resources based on wood fuel

A number of original technical solutions of energy supply system of technological processes of wood harvesting and production of chips in the cutting area and upper warehouse are presented. It is proposed to use generator gas from chips instead of traditional motor fuel. The autonomous power supply system includes a power plant with a DC motor and a hydraulic station, a power cable for transmitting electrical energy and a power plant. The power plant is installed on the chassis of the technological machine. The power plant equipment is located on a separate car trailer chassis. The power plant includes a battery of electrical energy, a DC generator, a heat engine on the generator gas, gas generators and a container with a fuel reserve. For cable rolling along the cutting area, special patented rollers are offered. The use of this system can save up to 870 liters of motor fuel from non-renewable resources per 1,000 cubic meters of harvested wood.

DESIGN AND ANALYSIS OF PNEUMATIC BAG AIR JACK

Drivers need lifting device jack with notch fits in place under the vehicle in the proper location during changing tires, also in workshops or maintenance centers jacks required for maintenance and refurbishment of parts, this device made the job faster and easy. Traditional car trailers use a mechanical feature to allow the human to raise the vehicle by manual force, by using the screw thread power or hydraulic jack which uses hydraulic power. The other way for lifting cars are pneumatic air bags, these bags are highly effective in industrial, maintenance applications and construction. In order to study this modern technology development and obtain good air bag design, which can lift and sustain the weight of more than 1200 kg estimated car weight, Solid works software used to analyze the weak points of pneumatic airbag. In this paper pressure used 249809.6 N/m^2 by imposing a weight of 1250 kg, Using natural rubber an as air bag material with two cases of thickness 1 mm, 3 mm, three behaviors of air bag tested (Von Mises stress, Strain and Deformation in two directions) analyzed, the results shows that the 1 mm thickness cannot sustain the load and pressure and weakest area lays between connection natural rubber and metal cast iron which contact the body of the car.

Analysis of a Broken Pin on the Brake System of a Car Trailer

Fatigue of materials is the degradation process that results from the cyclical dynamic loading of components in combination with other internal or external factors, e.g. corrosion, defects, etc. This paper mainly focuses on the analysis of the causes leading to the damage of a pin in a car trailer´s braking system. The damage of the pin was caused by a few, mutually independent, parameters. Several techniques such as macroscopy, microscopy (light, SEM) and dimension measurement were used for the damage analysis. The material and geometry of the pin were the main issues identified leading to the failure of the part in question.

Modeling and strength analysis of the prototype of the multi-tasking car trailer

The subject of the paper is modeling and strength analysis of the prototype of the multi-tasking car trailer. The innovativeness of the solutions applied consists in the combination of several single-purpose trailers into one, allowing for multitasking and the combination of several specialized trailers. Using the author's solution, the prototype of a multi-purpose trailer has been developed, which has the characteristics of several specialized trailers, such as for the transportation of general cargo, kayaks, motorcycles, quads etc. The model has been created by using SolidWorks package and it has been used for full strength analysis by simulation module. The sample analysis results cover various load configurations with respect to selected trailer construction components.

The Impact of Using Trailers on the Fuel Consumption

The amount of fuel consumed may also be influenced by driving style, speed as well as by the need for the use of passenger car trailers. This paper deals with the impact of using such trailers on the amount of fuel consumed. Measurement of the impact of the passenger car trailer on fuel consumption was carried out during driving at constant speed and during acceleration. The measurements were performed by driving test on a flat road. The first part of the paper deals with the driving resistances which influence fuel consumption during driving at constant speed and during acceleration on the flat road. The second part describes the vehicle used for measurements and measuring equipment. The conclusion of the paper includes the principles to reduce the impact of passenger car trailers on the amount of fuel consumed.

Повышение эффективности эксплуатации лесовозных автопоездов, оснащённых устройством для управления поворотной осью прицепа

The concept of systemic design of forest machines in the new economic conditions is proposed in the article. The main provisions of the choice of a mechanism for controlling the trailer of a road train on the basis of a technical and economic comparison of options are given. The main characteristics of the management of the road train and the efficiency of the technological process of transportation are determined. The proposed work deals with the issues of controllability of vehicles, which is of considerable interest for the purpose of using such equipment for forest machines, which would provide movement over a different reference surface (snow, sand, marsh etc). It is proposed to improve the electropneumatic design of the trailer drive, taking into account the numerous and changing factors. The analysis of timber car trailer constructions is given. The advantages and disadvantages of wood transportation by multi-tier road train are considered. The main types of road sections. The article analyzes the factors influencing the operational condition of roads. The road junctions are the places where the road accident most often occurs. The probability of ensuring reliability of functioning of separate elements of the highway and also road in general in time of close conditions of operation with technical or economic advantages in comparison with traditional decisions is considered. A graph is presented for determining the speed of the road train according to the proposed method for various conditions and factors. The method of finding the transfer functions of a complex multi-mass mechanical system "VAD" is proposed. The economic efficiency of the truck fleet is determined by the specific costs of transportation of timber, representing the ratio of the sums of costs.

Line-Scan Stereo Using Binary Descriptor Matching and Regularization

We present a line-scan stereo system and descriptor-based dense stereo matching for high-performance vision applications. Additionally we introduce a post-processing step based on total variation (TV) regularization for robust disparity estimation. Descriptor-based matching utilizes the Stochastic Binary Local Descriptor (STABLE). The performance of STABLE was shown to be superior to other binary descriptors, both w.r.t. stereo reconstruction quality as well as runtime performance. Regularized estimation of disparity maps is suggested as a hierarchical and iterative post-processing procedure where the Pseudo-Huber-TV norm was employed. We describe the hardware setup consisting of two line-scan cameras mounted in a car trailer and observing the road surface. Presented are results of 3D road surface reconstruction which are used in applications of road infrastructure maintenance.