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Trudy NAMI

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No 3 (2020)
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AUTOMOBILE DEVELOPMENT

6-13 195
Abstract

Introduction. The safety level of buses design, which transport a large number of passengers should constantly improve and include the safety of buses seat belts, seats, head restraints, bodywork, etc. The purpose of the study was to assess the bus passengers safety effectiveness based on the using various seat belts types depending on the distance between the bus seats backs.

Methodology and research methods. Experimental studies were carried out by means of field test method in accordance with the UN Rules for certified equipment and instruments.

Scientific novelty and results. The results of the study of various types seat belts effectiveness with a distance between the seats of 680, 730 and 780 mm have been obtained.

Practical significance. Based on the analysis of the experimental results, recommendations regarding requirements for the design of buses and methods for testing them when making changes and additions to TR TS 018/2011 were proposed.

14-23 189
Abstract

Introduction. Currently, an intensive development is being carried out to create tracked vehicles equipped with traction motors, the use of which practically eliminates the mechanical drive (friction clutches or brakes) controls, organizing stepless rectilinear motion and rotation together with the partial kinetic recuperation of braking energy.

The purpose of the study was to conduct a comparative analysis of the electromechanical transmissions schemes of tracked vehicles with two traction electric motors.

Methodology and research methods. To provide the possibility of a electromechanical transmissions comparative analysis the article presented kinematic and power link equations which made it possible to describe in general terms the transmission-rotation mechanisms of tracked vehicles equipped with two traction motors. The following variants of the circuit design of the transmission were compared: on-board drive of the drive wheels, separate drive for rectilinear movement and rotation, joint drive for rectilinear movement and rotation. The criterion for evaluating electromechanical transmissions was the value of the installed capacity of electric motors (the product of the maximum moment and the maximum rotational speed of the rotor shaft), referred to the power costs necessary to ensure rectilinear motion. To carry out the calculations, a number of operational operating modes of tracked vehicles were formed.

Scientific novelty and results. The methods presented in this work allowed to conduct a comparative assessment of the applied various circuit decisions effectiveness of the transmission-rotation mechanisms in the developed tracked vehicles at the design stage. Their distinctive feature was the application of a single approach to the obtained solutions analysis. The result of the study was a scientifically based choice of rational schemes of transmission-rotation mechanisms for high-speed tracked vehicles with two traction electric motors.

Practical significance. In the framework of the article, a number of rational circuit solutions for the transmission-rotation mechanisms of tracked vehicles have been obtained, the use of which will reduce the total installed capacity of the traction electric drive and, accordingly, reduce the weight and size parameters of the electric motors used.

Continuation. Start of article in previous issue

24-34 125
Abstract

Introduction. This article describes the observability problem for navigation parameters of road vehicles, namely the coordinates and the heading angle, which are used by automated driving systems. The measurement quality of navigation parameters can vary substantially depending on vehicle operating conditions ranging from high precision measurements to complete unavailability of navigation data. Low quality of navigation data may render operation of automated driving systems impossible. To solve this problem, this work uses indirect measurements implemented if the form of so-called observers, which are able to identify the vehicle navigation parameters regardless of its operating conditions.

The purpose of the study is to improve observability of the vehicle navigation parameters.

Methodology and research methods. The observers of the vehicle navigation parameters were implemented using a kinematic model of vehicle’s motion and Kalman filtering. The accuracy of the elaborated observers was estimated by root mean square errors and maximum deviations from the reference data acquired by a high precision navigation system in various driving conditions.

Scientific novelty and results. The article provides a detailed analysis of the observability problem regarding the vehicle navigation parameters. It also proposes a development approach for observers of the vehicle heading angle and coordinates based on the Kalman filter. The parameters calculated by the elaborated observers were verified through a comparison with high precision measurements.

The practical significance of the work is constituted by the elaborated observers, which provide an improved quality of the vehicle navigation parameters.

ENGINE DEVELOPMENT

35-45 152
Abstract

Introduction. Modern research in the area of internal combustion engines are focused on searching and investigating the technologies that will improve fuel efficiency and decrease emissions. Application of dual-fuel engines is considered as a potential solution of these problems. In the dual-fuel engine, natural gas-air mixture is ignited by a small amount of the diesel fuel directly injected into a combustion chamber. Pilot fuel injection parameters can strongly affect combustion process. This paper is devoted to the investigation of the effect of fuel supply parameters on the dual-fuel engine combustion process.

The purpose of this paper is to investigate the effect of such parameters as pilot fuel mass, pilot fuel injection pressure, pilot fuel injection timing and excess air ratio on combustion process.

Methodology and research methods. Based on the data obtained during the bench tests conducted with the use of the measurement equipment, the dependences of engine characteristics from the fuel supply parameters under review and the heat release rate curves were obtained. Optimal value for every investigated parameter was chosen. The combustion process indicators were calculated for each operating mode.

Scientific novelty and results. The result of the investigation is consist in obtaining new data on combustion process parameters adjusting based on the heat release rate curves for the operating modes under review. Based on the obtained results, coefficient m for heat release rate was calculated for each operating point, according to Vibe’s equation.

Practical significance. The results of the conducted investigation can be applied when designing modern heavy-duty dual-fuel engines.

REVIEWS, ARTICLES FOR DISCUSSION

46-59 193
Abstract

Introduction. The article provides an overview of the “Zimniy gorod” technological competition held in Russia during 2019, which is a competition of unmanned vehicles moving autonomously in winter conditions at night, taking into account urban conditions and the peculiarities of vehicles operation in Russia. One of the five finalists of the competition was the BaseTracK team, which participated in the Gazelle Next EVA electric minibus. The article describes and substantiates the technical solutions used in the preparation for the competition and implemented in an experimental vehicle.

The purpose of the study was to develop an autonomous wheeled vehicle for participation in the “Zimniy gorod” technology competition.

Methodology and research methods. Research was carried out on the basis of vehicle motion theoretical fundamentals, theoretical mechanics, electrical engineering, the theory of mathematical analysis, the theory of experiment, computer modeling methods, the theory of automated control, methods of synthesis of control systems and communication facilities, methods of processing video information in technical vision systems.

Scientific novelty and results. The scientific novelty is the set of selected technical solutions and methods for adjusting the trajectory controllers and speed control of an unmanned vehicle, which ensure safe and efficient movement in difficult urban and winter conditions. The distinctive features of the implemented project include the use of optimal vehicle control schemes depending on the formulation of the transport problem, high-precision mapping of the terrain by aerial photography as well as the refusal to use lidar technologies.

Practical significance. The description of the unique “Zimniy gorod” competition, which has no analogues in the world, the results obtained and the methodology for designing an unmanned vehicle for difficult operating conditions are of practical importance, as well as the consideration and analysis of practical errors.

60-65 132
Abstract

Introduction. The rapid development of road transport in recent years has led to significant environmental pollution, including solid particles caused by tire and road wear.

The purpose of the study was to review and analyze the current state of research on particulate matter emissions caused by tire and roadway wear when vehicles are moving.

Methodology and research methods. In this work, basing on domestic and foreign materials, the method of systematic analysis of solid particles emissions resulting from the interaction of tires and roadways was applied.

Scientific novelty and results. The article analyzed some modern domestic and foreign studies on emissions of solid particles caused by tire and roadway wear when vehicles were moving.

Practical significance. The main research directions of solid particles emissions resulting from tire and roadway wear have been determined.

66-72 177
Abstract

Annotation. Introduction. An electrically driven throttle unit is used in modern internal combustion engines (ICE) with quantitative control. The throttle unit makes it possible not only regulate the amount of incoming air, but also measure the parameters of the air passed through the throttle unit.

The purpose of the study was to develop an algorithm for the ICE control system.

Methodology and research methods. The ICE control systems algorithms were based on the application of physical patterns.

Scientific novelty and results. To work out the needed algorithm high-precision models were used, in particular, a model that took into account the leakage of the simulated throttle unit caused by the gaps necessary for the normal throttle unit operation. To determine the amount of air passed through the throttle unit with the help of the ICE control system, it was proposed to use the model considering the area of the slot formed due to the inequality of the linear size of the throttle valve small axis and the inner diameter of the throttle channel. In case the area of the slot in the model is not considered it can lead to a significant error, especially when the absolute angle of the throttle position is less than 30 degrees. The existing model of the throttle unit passage area was taken into account and a more accurate model of the throttle unit passage slot area was proposed. The results of calculating the relative error and the amount of the passed through the throttle unit air for the models under consideration were presented.

Practical significance. The developed recommendations can be used in the elaboration of software algorithms for the electronic control unit of the internal combustion engine control system.

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ISSN 0135-3152 (Print)