Construction Vehicles Research Articles

Hierarchical Model Predictive Control for Hydraulic Hybrid Powertrain of a Construction Vehicle

Hybrid hydraulic technology has the advantages of high-power density and low price and shows good adaptability in construction machinery. A complex hybrid powertrain architecture requires optimization and management of power demand distribution and an accurate response to desired power distribution of the power source subsystems in order to achieve target performances in terms of fuel consumption, drivability, component lifetime, and exhaust emissions. For hybrid hydraulic vehicles (HHVs) that are used in construction machinery, the challenge is to design an appropriate control scheme to actually achieve fuel economy improvement taking into consideration the relatively low energy density of the hydraulic accumulator and frequent load changes, the randomness of the driving conditions, and the uncertainty of the engine dynamics. To improve fuel economy and adaptability of various driving conditions to online energy management and to enhance the response performance of an engine to a desired torque, a hierarchical model predictive control (MPC) scheme is presented in this paper using the example of a spray-painting construction vehicle. The upper layer is a stochastic MPC (SMPC) based energy management control strategy (EMS) and the lower layer is an MPC-based tracking controller with disturbance estimator of the diesel engine. In the SMPC-EMS of the upper-layer management, a Markov model is built using driving condition data of the actual construction vehicle to predict future torque demands over a finite receding horizon to deal with the randomness of the driving conditions. A multistage stochastic optimization problem is formulated, and a scenario-based enumeration approach is used to solve the stochastic optimization problem for online implementation. In the lower-layer tracking controller, a disturbance estimator is designed to handle the uncertainty of the engine, and the MPC is introduced to ensure the tracking performance of the output torque of the engine for the distributed torque from the upper-layer SMPC-EMS, and therefore really achieve high efficiency of the diesel engine. The proposed strategy is evaluated using both simulation MATLAB/Simulink and the experimental test platform through a comparison with several existing strategies in two real driving conditions. The results demonstrate that the proposed strategy (SMPC+MPC) improves miles per gallon an average by 7.3% and 5.9% as compared with the control strategy (RB+PID) consisting of a rule-based (RB) management strategy and proportional-integral-derivative (PID) controller of the engine in simulation and experiment, respectively.

A deep‐learning‐based computer vision solution for construction vehicle detection

AbstractThis paper aims at providing researchers and engineering professionals from the first step of solution development to the last step of solution deployment with a practical and comprehensive deep‐learning‐based solution for detecting construction vehicles. This paper places particular focus on the often‐ignored last step of deployment. Our first phase of solution development involved data preparation, model selection, model training, and model validation. Given the necessarily small‐scale nature of construction vehicle image datasets, we propose as detection model an improved version of the single shot detector MobileNet, which is suitable for embedded devices. Our study's second phase comprised model optimization, application‐specific embedded system selection, economic analysis, and field implementation. Several embedded devices were proposed and compared. Results including a consistent above 90% mean average precision confirm the superior real‐time performance of our proposed solutions. Finally, the practical field implementation of our proposed solutions was investigated. This study validates the practicality of deep‐learning‐based object detection solutions for construction scenarios. Moreover, the detailed information provided by the current study can be employed for several purposes such as safety monitoring, productivity assessments, and managerial decision making.

Can Exposure to Whole-body Vibration Affect the Prevalence of Musculoskeletal Disorders in Operators of Construction Vehicles? A Study in Construction Projects

Can Exposure to Whole-body Vibration Affect the Prevalence of Musculoskeletal Disorders in Operators of Construction Vehicles? A Study in Construction Projects

ПЕРСПЕКТИВЫ ПРИМЕНЕНИЯ ЧЕРВЯЧНЫХ ПЕРЕДАЧ В КОНСТРУКЦИЯХ АВТОТРАНСПОРТНЫХ СРЕДСТВ

The article analyzes the prospects for the use of worm gears in the construction of vehicles. A review of the method of calculating the worm gear has been carried out, approaches to the selection of materials for the worm itself and the worm wheel have been analyzed. A comparative analysis of the characteristics of improved and normalized medium-carbon steels and cast irons has been carried out. The characteristics of materials characterized by the best antifriction and anti-seize properties, in particular, tin bronzes, are given. The methods for predicting the reliability of a worm pair as well as methods for increasing the resource have been considered. The choice of the material of the worm gear depending on the sliding speed has been justified. Calculations have been given to prevent failures in the worm pair: chipping of the working surfaces of the teeth, kinking of the worm wheel tooth, seizing and wear, breakage of the worm's body, overheating, jamming of the gear and others.

Multiobjective Optimal Predictive Energy Management for Fuel Cell/Battery Hybrid Construction Vehicles

Fuel cell/battery hybrid construction vehicles (FCHCVs) have shown great promise; however, the complex working conditions of construction vehicles pose considerable challenges to the performance and energy management of a fuel cell/battery hybrid system. In this paper, multiobjective optimal model predictive control (MOMPC)-based energy management for FCHCVs is explored. A system model is established that includes an economic model and a lifetime model. In the MOMPC framework, multiobjective optimization is conducted to enhance fuel cell durability and battery lifetime while minimizing costs. Since the energy management problem is a nonlinear problem with hard state constraints, it can be difficult to resolve online. The multiobjective approach employs an adaptive weight-adjustment method based on a fuzzy logic algorithm. An economic evaluation of the FCHCV is conducted over its life cycle with respect to the power source size. Simulation results indicate economic savings and prolonged battery lifetime with the MOMPC-based strategy, compared with conventional benchmarks.

Method of estimating the change in life cycle CO2 due to transport system development incorporating micro-traffic flow simulation

In this research, a method of estimating the system overall life cycle CO2 emissions including vehicle traveling, infrastructure construction, and new manufacture of vehicles is constructed in order to comprehensively evaluate the change in CO2 emissions associated with transport system development. In particular, congestion of automobiles due to traffic signals and turning left and right, etc., and the detailed driving behavior of vehicles including mixing of light rail transit (LRT) and automobiles on the road can be analyzed by micro-traffic flow simulation. A framework is presented for the introduction of LRT that enables conversion from parallel fixed route buses and the increase in congestion of automobiles due to the reduction in the number of traffic lanes to be taken into consideration. As a result of application of this estimation method to a case study, the effect of automobile congestion brought about by the reduction in the number of traffic lanes and the introduction of LRT priority signals on CO2 emissions was quantitatively determined.

Hybrid DNA/RNA nanostructures with 2'-5' linkages.

Nucleic acid nanostructures with different chemical compositions have shown utility in biological applications as they provide additional assembly parameters and enhanced stability. The naturally occurring 2'-5' linkage in RNA is thought to be a prebiotic analogue and has potential use in antisense therapeutics. Here, we report the first instance of DNA/RNA motifs containing 2'-5' linkages. We synthesized and incorporated RNA strands with 2'-5' linkages into different DNA motifs with varying number of branch points (a duplex, four arm junction, double crossover motif and tensegrity triangle motif). Using experimental characterization and molecular dynamics simulations, we show that hybrid DNA/RNA nanostructures can accommodate interspersed 2'-5' linkages with relatively minor effect on the formation of these structures. Further, the modified nanostructures showed improved resistance to ribonuclease cleavage, indicating their potential use in the construction of robust drug delivery vehicles with prolonged stability in physiological conditions.

Tatyana Tolstaya’s “Sleepwalker in a Fog” or “The Life is a Dream” in a Neobaroque manner

The proposed analysis of the oneiric elements in the early prose writing by Tatyana Tolstaya, most notably in the short story “Sleepwalker in a Fog”, attributes the highest heuristic value to the traditional Baroque metaphor “life is a dream”, and attempts to close read the text by using this premise as a focal point. The stated metaphor which, as an impor-tant vehicle for construction of narrative reality, is present only implic-itly in the text, contains two distinct semantic aspects. The fi rst can be defi ned as the claim that the protagonist observes objective reality as a dream, with disintegrated and lessened attention, passively and absent-mindedly, since he is completely absorbed in his inner life. What con-stitutes reality for him is the activity of his spiritual sphere whereas the real world looks completely unreal, as if he were dreaming about it. The metaphor “life is a dream” has, however, another meaning which can be defi ned as an observation that reality can sometimes have a dreamlike character. Hence, the protagonist is not necessarily submerged into his inner life but rather observes the external world with sharp and vigilant perception, and has a strong feeling that what surrounds him is not real, i.e. that the external reality is objectively like a dream. There is no doubt that the reality of the late socialism as described in the short story “Sleepwalker in a Fog” has a quality of a chaotic, oneiric chronotope in which events evolve incoherently, illogically, and in a dreamlike manner.

Construction of vehicle driving cycle in Fuzhou

The current driving cycle in Europe is not consistent with China’s actual road conditions, and the traffic conditions in different cities of China also are discrepant. Therefore, it is increasingly urgent to build corresponding driving cycle based on the driving data of each city. In this paper, based on noise reduction pretreatment of vehicle driving data in three areas of Fuzhou city, K-means clustering is carried out on the first five principal components of the extracted kinematic segments obtained by principal component analysis. Then, three types of kinematic segments, which represent relatively smooth traffic, traffic congestion and smooth traffic, are obtained respectively. So the vehicle driving cycle is constructed, and the correlation coefficient between it and the sampling population for constructing is calculated. Finally, the error analysis method and correlation coefficient are used to verify the constructed driving cycle that is rational and representative.

Increase of strength of cast-iron cylinder liners of engines of road construction vehicles

Cylinder liners made of gray cast iron are quite widespread in the design of engines of road construction vehicles. The negative properties of this structural material include relatively low strength and high fragility. This increases the probability of both manufacturing and operational defects. Therefore, improving the performance of the considered parts is an urgent problem. A promising direction in this case is the use of chemical-and-thermal treatment. The aim of the work is to study the effect of chemical-and-thermal treatment of gray cast iron on strength. The paper investigates the strength of cast iron subjected to chemical-and-thermal treatment (thermal diffusion surface alloying). On the basis of experimental studies, the effect of the thickness of the hardened layer on the strength was studied. A numerical model is created in the Ansys software. The effect of the hardened layer on the strength of cylinder liners of engines of road-building vehicles is investigated.

Experiments all the way in programmatic design research

Experiments take various forms, have various purposes, and generate various knowledge; depending on how, when and why they are integrated in a design research study with a programmatic approach. This is what we will argue for throughout this article using examples and experiences from our now finalized Ph.D. studies. Reviewing the prevailing literature on research through design the overall argument is that design experiments play a core role both in conducting the research, in theory construction and in knowledge generation across the different design domains and methodological directions. However, we did not identify sources that explicitly discuss and operationalize roles and characteristics of design experiments in different stages of programmatic design research. The aim of this article is therefore to outline a (tentative) systematic account of roles and characteristics of design experiments. Building upon Schön’s definition of experiments in practice we propose adding to the prevailing understanding of experiments in research through design understanding and operationalizing design experiments (1) as initiators or drivers framing a research programme, (2) as ways to reflect on and mature the research programme serving as vehicles for theory construction and knowledge generation and finally (3) as a ‘designerly’ approach to the written knowledge dissemination and clarification of research contributions.

Experiments all the way in programmatic design research

Abstract Experiments take various forms, have various purposes, and generate various knowledge; depending on how, when and why they are integrated in a design research study with a programmatic approach. This is what we will argue for throughout this article using examples and experiences from our now finalized Ph.D. studies. Reviewing the prevailing literature on research through design the overall argument is that design experiments play a core role both in conducting the research, in theory construction and in knowledge generation across the different design domains and methodological directions. However, we did not identify sources that explicitly discuss and operationalize roles and characteristics of design experiments in different stages of programmatic design research. The aim of this article is therefore to outline a (tentative) systematic account of roles and characteristics of design experiments. Building upon Schön’s definition of experiments in practice we propose adding to the prevailing understanding of experiments in research through design understanding and operationalizing design experiments (1) as initiators or drivers framing a research programme, (2) as ways to reflect on and mature the research programme serving as vehicles for theory construction and knowledge generation and finally (3) as a ‘designerly’ approach to the written knowledge dissemination and clarification of research contributions.

OPTIMIZATION OF ENERGY COSTS AT THE STAGE OF DESIGNING AND REFINING OF THE PUSHER OF ENGINE GAS DISTRIBUTION MECHANISM

In order to optimize energy consumption at the design stage and fine-tuning the main components of the gas distribution mechanism, calculations were performed. The method of calculating annular gaps was used to select the rational dimensions of the pusher assembly design, as well as the gas distribution mechanism of the engine of construction machines. A pusher model is considered in the design scheme of the engine lubrication system for construction vehicles, which helps to refine the calculated data on the oil consumption of the main consumers. The data obtained accelerate the development of the engine design at the design, development and operation stages of machines and mechanisms. The main task was to calculate the pusher of the indicated type to obtain data on oil consumption through the annular gap formed by the sleeve and the pusher body.

Ways to Improve the Durability of Pneumatic Tires

Current trends of functional improvement of pneumatic car tires are described in the article. As a rule, these are the structural features of a car wheel that allow getting the nearest service station after a tire damage. The airless tire design eliminates the damages specific for pneumatic tires. They have been used for construction vehicles and military vehicles exclusively. However, improving the durability of pneumatic tires is relevant. This is due to the increase of free speed. There are two ways to improve the durability of automobile tires. The first way is to use tire damping, thanks to the new material structure of the tire. The second way is to use thermoelectric cooling to reduce thermal effects on the tire.

CREDO RADON UA – INFORMATION MODEL FOR CALCULATION OF ROAD CONSTRACTION

CREDO RADON UA software provides an automated calculation of the strength of the pavement structures of non-rigid and rigid types, as well as the calculation of the strengthening of existing structures. In the article, one can see the main features and functionality of the CREDO RADON UA software, the main points in the calculations according to the new regulations. Information support of the design process includes necessary databases, informational and helping materials that make up the full support of the pavement design process. The concept of CREDO RADON UA 1.0 software is made on the use of elasticity theory methods in calculations of initial information models of pavements. Performing optimization calculations, the roadwear in CREDO RADON UA is designed in such a way that no unacceptable residual deformation occurs under the influence of short-term dynamic or static loading in the working layer of the earth bed and in the structural layers during the lifetime of the structure. The calculation algorithms were made in accordance with the current regulatory documents of Ukraine. CREDO RADON UA software allows user to create information bases on road construction materials and vehicles as part of the traffic flow for calculations. The presented system of automated modeling makes it easier for the customer to control the quality of design solutions, to reasonably assign designs to layers of reinforcement, to quickly make comparisons of calculations of different designs for the optimal use of allocated funds. Prospects for further improvement of the program should be the results of theoretical and experimental studies on filling the databases, which are used as information support for automated design of road structures. Keywords: CREDO RADON UA, road, computer-aided design, repair project, road pavement, strengthening, construction, rigid pavement, elasticity module, a transport stream, calculation method, information support, dynamic or static loading.

Conical rubber suspension springs in the construction of railway vehicles

An important category of rubber suspension elements is represented by the tapered springs, to which the rubber is subject to shear and compression request. Such type of springs has a widespread use in the construction of rolling stock because, in addition to the advantages of good use of the rubber in terms of request to the stress, they are easier to use. The shape and dimensions of these springs make them usable in a very wide range, from elements for suspending aggregates to suspension elements. The paper presents the main constructive types of conical springs and their calculation elements. Special reference is made to the use of conical springs in the suspension of railway vehicles.

Sensor subsystem design for small unmanned surface vehicle

The construction of unmanned vehicles is a major trend in a modern robotics and automation. One of the promising branches is the development of unmanned boats and surface vehicles (USV). They possess the great variety of possible applications, including environmental studies, military and security issues. In this paper, we consider the design and rapid prototyping of sensory subsystem for small-sized USV. The proposed sensor system incorporates the lidar, Doppler radar rangefinder and video camera in a waterproof housing. The housing is made with additive technology and provides the efficient and rigid placement of chosen set of sensors. The circuitry and design of the sensory subsystem are given and discussed in comparison with existing solution. The prototype of the system is described and the results of its experimental testing are provided.

Automatic control of air pressure in tires as a factor of safety improvement of wheeled vehicle operation in agricultural sector

The article is devoted to the problem of automatic modes of tire pressure regulation in transport vehicles used generally in agriculture where there are a lot of roads performing in very bad condition with mud. Almost all kind of wheeled vehicles could be fitted with air pressure regulation systems. Limits of tire pressure usually regulated by manufacturer so any kind of engineering modifications of tire systems should work in that limits strictly bordered by manufacturer of vehicle and tires. The presented article contains engineering based and practical orientated way to improve drive safety and operator working conditions. Each type of road has such characteristics as safety speed, angle of rollover etc. The authors propose mathematical model of regulation process on the basis of the above mentioned factors of road and vehicle functioning. In the process of modern construction of vehicles the way of module upgrades of existing vehicles becomes more and more popular. In this regard the authors try to propose one of the compromise universal solution for the problem of automatic tire pressure control and regulation.

Considerations on the V-block type shape suspension springs at the rail vehicles

In the paper is presented some theoretical considerations underlying the use of these springs in the railway vehicle constructions. The use of these springs as elastic suspension systems is justified by a few advantages that they offer in service, such as: simplicity, weight and low gauge, do not require guides, work without wear and have a high reliability. The elasticity in the three-principal: vertical, horizontal-transverse and longitudinal directions recommends the use of these springs in the axle’s suspension of the vehicle. As an application it is presented the axle suspension dimensioning elements in the case of a carload subway vehicle.

A Fundamental Study on the Methodology used to Estimate the Number of Construction Vehicles for Designing Pavements in an Apartment Complex

A Fundamental Study on the Methodology used to Estimate the Number of Construction Vehicles for Designing Pavements in an Apartment Complex