Idle Speed Research Articles

A New Approach for Static NOx Measurement in PTI

NOx emissions in vehicles are currently only controlled through the homologation process. There is a lack of knowledge to assess and control real NOx emissions of vehicles reliably. Even if vehicles in EU-27 are subject to Periodical Technical Inspection (PTI), NOx are not among the pollutants currently being controlled. For PTIs, tests need to be simple, quick, inexpensive, representative, and accurate. Ideally, tests need to be carried out under static conditions, without the need for a power bench or complex equipment. In this paper, a new approach for measuring NOx in PTI is proposed. The method has been developed and validated at a PTI Spanish station to ensure feasibility and repeatability. This method is based on the relationship between the “% engine load” value and exhaust NOx concentration at idle engine speed. Starting from the state of minimum possible power demand in a vehicle (idling and without any consumption), a load state with an average 98% increase in engine power demand is generated by connecting elements of the vehicle’s equipment. The relationship between power demand (through the “% engine load” value) and NOx concentration is then analyzed. The quality and representativity of this relationship have been checked with a p-value lower than 0.01. The method has been compared with a different NOx measurement technique, based on the simulation on a test bench and the ASM 2050 cycle, showing better performance in terms of repeatability and representativeness. The “% engine load” dispersion with the new approach is 7%, which ensures the reliability and repeatability of the method. The results show that the proposed method could be a valuable tool in PTI to detect high NOx emitting vehicles and to obtain information from the diesel vehicles fleet.

Idle speed control with low-complexity offset-free explicit model predictive control in presence of system delay

The requirement for continual improvement of idle speed control (ISC) performance is increasing due to the stringent regulation on emission and fuel economy these days. In this regard, a low-complexity offset-free explicit model predictive control with constraint horizon is designed to regulate the idle speed under unmeasured disturbance in presence of system delay with rigorous formulation. Particularly, we developed a high-fidelity 4-stroke gasoline-direct injected spark-ignited engine model based on first-principles and test vehicle driving data, and designed a model predictive ISC system. To handle the delay from intake to torque production, we constructed a control-oriented model with delay augmentation. To reject the influence of torque loss, we implemented the offset-free MPC scheme with disturbance model and estimator. Moreover, to deal with the limited capacity assigned for the controller in the engine control unit and the short sampling interval of the engine system, we formulated a low-complexity multiparametric quadratic program with constraint horizon in presence of system delay in state and input variables, and obtained an explicit solution map. To demonstrate the performance of the designed controller, a series of closed-loop simulations were performed. The developed explicit controller showed proper ISC performance in presence of torque loss and system delay.

Organization of Six-Cylinder Tractor Diesel Working Process

The purpose of the work is to consider the organization of the working process of six-cylinder diesel engines with a power of 116 and 156 kW and exhaust gas recirculation. The following systems and components were used in the experimental configurations of the engine: Common Rail BOSСH accumulator fuel injection system with an injection pressure of 140 MPa, equipped with electro-hydraulic injectors with seven-hole nozzle and a 500 mm3 hydraulic flow; direct fuel injection system with MOTORPAL fuel pump with a maximum injection pressure of 100 MPa, equipped with MOTORPAL and AZPI five-hole nozzle injectors; two combustion chambers with volumes of 55 and 56 cm3 and bowl diameters of 55.0 and 67.5 mm, respectively; cylinder heads providing a 3.0–4.0 swirl ratio for Common Rail system, 3.5–4.5 for mechanical injection system. The recirculation rate was set by gas throttling before the turbine using a rotary valve of an original design. The tests have been conducted at characteristic points of the NRSC cycle: minimum idle speed 800 rpm, maximum torque speed 1600 rpm, rated power speed 2100 rpm. It has been established that it is possible to achieve the standards of emissions of harmful substances: on the 116 kW diesel engine using of direct-action fuel equipment and a semi-open combustion chamber; on the 156 kW diesel using Common Rail fuel supply system of the Low Cost type and an open combustion chamber.

R1234yf/R134a Based Refrigerant Mixture for Automobile Air Conditioning Systems: A Thermodynamic Approach

The environmental protocols lead to analysing various refrigerants minimum global warming potential (GWP) to substitute high GWP R134a in an automobile air conditioning (AAC) system. The present study deals with the thermodynamic analysis of the AAC unit using R1234yf/R134a refrigerant mixtures under three-vehicle speed conditions such as idling (L-900 rpm), city limit (M-1800 rpm), and high speed (H-2700 rpm). The mass fractions of R1234yf/R134a such as 0:1, 1:0, 0.9:0.1, 0.8:0.2, 0.7:0.3, 0.6:0.4 and 0.5:0.5 were considered in this analysis. The cooling capacity and coefficient of performance (COP) of R1234yf were observed to be poorer than that of the existing R134a by up to 10.4% and 8.3%. The addition of R134a in R1234yf reduced the performance gap between the existing R134a system under all the speed conditions. There was an increase cooling capacity and COP of the AAC by up to 6.4% and 4.9% was found with the addition of 0.5 mass fraction of R134a in R1234yf. However, the GWP of the refrigerant mixture was increased with rise in R134a mass fraction of which causes more direct CO2 emission from the AAC system. This study prevailed that the use of R1234yf/R134a mixture (0.5:0.5 by a mass fraction) performed very much similar to that of R134a in the AAC unit. Further, the R1234yf/R134a mixture (0.9:0.1 by a mass fraction) is suggested to use in the AAC system to satisfy the environmental protocols (GWP < 150).

Study of Energy Consumption of a Bucket Conveyor in a Jig Concentrator Plant in a Hard Coal Mine

The subject of the discussion is oriented toward limiting the energy consumption of the bucket conveyor used in jig concentrator plants by controlling its speed. A method of predictive control of the bucket conveyor speed is presented. It allows for reducing the energy consumption due to appropriate selection of bucket movement speed to ensure the nominal filling of buckets along the entire length of the conveyor. This approach enables limiting the idling speed of the conveyor, extend its life, and also reduce the electricity consumption of the entire system. Experimental studies, carried out at the “Sośnica” Coal Mine working facility, confirmed that the use of a predictive algorithm for controlling the bucket conveyor speed and adapting the bucket speed to the current load decreased in energy consumption n by 9.6%, with 80% of the filling conveyor.

Vector control system of electric drive of grain machine conveyor

Purpose. Synthesis of an automatic control system for an asynchronous electric drive of a grain thrower conveyor based on a frequency converter with vector control.&#x0D; Methodology. The research was carried out using methods of mathematical modeling of an electric drive; using methods of tuning optimization and regulator synthesis. The technique of synthesis of vector control systems is based on the representation of a non-stationary multi-connected object, which is an AC machine, in the form of a set of stationary subobjects with linear links in the main control channels.&#x0D; Findings. The study of the work of the subordinate regulation system, which implements the principles of vector control, oriented along the vector of the rotor flux linkage, has been carried out. The modeling of the processes of AM excitation, AM start-up at idle speed, nominal load surge, speed reduction has been carried out. It was found that the synthesized system is characterized by good quality indicators. The overshoot at start does not exceed 5%, the regulation time is 0.4 s, the torque limitation is carried out at a predetermined level. It has been proven that oscillatory processes in transient modes with significant torque surges with classical settings of loop regulators can be compensated by introducing artificial cross-links into the control part of the electric drive.&#x0D; Originality. A system of subordinate regulation of the blood pressure of the grain thrower trimmer conveyor has been implemented to set the speed of the grain flow with the aim of throwing grain at a given distance by creating an appropriate ballistic flight trajectory, which ensures a reduction in losses from damage to grain.&#x0D; Practical value. The structure of the vector control system of a frequency-controlled asynchronous electric drive with additional compensating cross-connections between active and reactive energy control channels is proposed to improve the quality indicators of the system.

Time response analysis for two-phase PMSM with two-sectional phase windings

A new approach to investigation of two-phase PMSM control methods on the level of phase windings sections is presented. For two-phase PMSM with two-sectional windings all control methods are considered from a unified position. Section and phase usage variants implementable at all possible section connection schemes are determined and classified; armature magnetic induction vector amplitudes and angle positions are calculated. The vectors are grouped by graphical representation, phase usage variant and section connection scheme into sets, number of which leading to non-zero vectors and the zero vector is determined. A simulation is carried out, speed time response curves are calculated and compared; the affecting of section connection scheme and phase usage variant on speed transition time and idle speed is ascertained; groups are discovered, section connection schemes can be attributed to. The obtained results can be used in demand by drive developers to select the most suitable PMSM control method.

A new path of energy saving and emission reduction based on the choice of matching engine oil for tor traditional energy vehicles

Comparative test research for the same and different models with matching type oil has been carried outunder same and different conditions. The results show that the parameters such as idle speed, load calculation value, absolute position of throttle, injection pulse width and fuel repair value of all the tested engines are reduced to different degrees by using the matching type oil. Energy consumption, emissions and other indicators of vehicles with matching type of oil have been improved after long-term tracking, especially large diesel vehicles.

Simulation of the force factors causing engine idling to vibrate

The article provides a diagram and a description of the physical reasons that cause the engine to vibrate on the suspension at idle. The substantiation of the assumption about the inertial nature of these reasons is given. The main dependences for modeling the force effects on the engine casing at idle modes are given. The above theoretical aspects of modeling oscillations at idle speed are confirmed by the results of experiments to determine the influence of the moment of inertia of rotating engine parts on the amplitude of its oscillations on the suspension.

Organization of the Six-Cylinder Tractor Diesel Working Process

The purpose of the work is the organization of the six-cylinder diesel engines (with a power of 116 and 156 kW) working process with exhaust gas recirculation. The following systems and components were used in the experimental configuration of the engine: Common Rail BOSСH accumulator fuel injection system with an injection pressure of 140 MPa equipped with electro-hydraulic injectors with 7-hole nozzle and a 500 mm3 hydraulic flow; direct fuel injection system with MOTORPAL fuel pump with a maximum injection pressure of 100 MPa, equipped with MOTORPAL and AZPI five-hole nozzle injectors; two combustion chambers with volumes of 55 and 56 cm3 and bowl diameters of 55 and 67.5 mm; cylinder heads providing a 3-4 swirl ratio for Common Rail system, 3.5-4.5 for mechanical injection system; recirculation rate was set by gas throttling before the turbine using original design rotary valve. The tests were conducted at characteristic points of the NRSC cycle: minimum idle speed 800 rpm, maximum torque speed 1600 rpm, rated power speed 2100 rpm. It is established: achievement of emission standards for the 116 kW diesel engine is possible with the use of direct-acting fuel equipment and a semi-open combustion chamber; on the 156 kW diesel - using the Low Cost type common Rail fuel supply system and an open combustion chamber.

Behavior of the particulate matter (PM) emitted by trackless rubber-tyred vehicle (TRTV) at an idle speed under different movement conditions and ventilation optimization

The particulate matter (PM) emitted by a trackless rubber-tyred vehicle (TRTV) in coal mines can seriously threaten the health and safety of the exposed workers underground. In this paper, in order to effectively reduce the PM concentration and improve the underground working environment, a combination of numerical simulations and field measurements was adopted to study the migration distribution of the PM emitted by a TRTV at an idle speed for 60 s under different movement conditions, and the dilution effects of the ventilation rate on the PM. The results showed that under different movement conditions, the PM mainly moved along the floor of the roadway, but upward diffusion trends were shown overall, which meant that the chambers are in high-risk areas. Field measurements were then performed under the two conditions to verify the effectiveness of the simulations. Furthermore, the dilution effects of the increased ventilation rate on the PM were analyzed. It was concluded that the optimal dilution ventilation rate under condition 1 was 4600m3/min, and that under condition 2 was 2800m3/min. Accordingly, the driver of the TRTV should try to move forward when entering the chamber.

Investigation of Temperature Distribution inside the Diesel Particulate Filter (DPF) during the Drop to Idle Test (DTIT) Performed at Steady-State and Worst-Case Driving Cycles

&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;The present work investigates the temperature distribution inside the diesel particulate filter (DPF) regeneration during the drop to idle test (DTIT), which is considered as life-threatening to the DPF. To study this scenario in detail, experiments were carried out with the filter volume of 3 liters. Initially, the experiments were done at a steady-state level, where the optimization for optimal soot loading was performed with setpoint temperature varying from 620 to 660°C. The soot loading was varied from 8 g/l to 11 g/l. The DTIT performed at a steady-state level indicated the different peak temperatures attained inside the DPF at different locations. The peak temperature was found to be in the center plane of the filter. The next peak temperature locations were found to be in downstream of the filter at different locations, which shows the non-uniformity in the soot deposition inside the filter. The temperature gradient was estimated based on the measured peak temperature and was higher at the center plane of the filter. The different soot loading and the setpoint temperature were correlated for different cases. The importance of selecting the optimal soot loading and setpoint temperature were discussed. The time taken from the start of idle speed to reach the peak temperature from the DTI test suggests the importance of the setpoint temperature, which is evident from the fact that it is promoting the burning rate of the accumulated soot with a higher setpoint. Decreasing the soot loading with relaxing the setpoint temperature can be a better option to operate the DPF in the safe zone and to avoid the failure of the DPF. A similar study was carried out at the vehicle level at different operating conditions. The temperature distribution inside the DPF in different worst-case driving maneuvers was measured.&lt;/div&gt;&lt;/div&gt;

Model Predictive Control-based Engine Idle Speed Regulation with Various Coordinated Controls Using an Instantaneous Engine Model

Model Predictive Control-based Engine Idle Speed Regulation with Various Coordinated Controls Using an Instantaneous Engine Model

Effect of Ethanol Additives on Combustion and Emissions of a Diesel Engine Fueled by Palm Oil Biodiesel at Idling Speed

Biodiesel is known for its high cetane number and high oxygen content among other advantages, but its high viscosity and density are not trivial issues for fuel flow and atomization, especially under idling conditions. Due to low cylinder temperature and incomplete combustion, engine idling is one of the worst operating conditions. As a common fuel additive, ethanol can address some of the shortcomings of biodiesel. This work evaluated the combustion and emission characteristics of different concentrations of ethanol additives on a diesel engine fueled with palm oil biodiesel under idling conditions. The results show that ethanol helps to increase peak cylinder pressure and heat release rate, suppressing the production of certain emissions with a maximum reduction in smoke opacity of 71%.

Influence of air temperature on warming up the engine of automotive vehicles

The air temperature has a significant effect on the warming up of the engine of automotive vehicles. To study this process, comparative experiments on the functioning of tractors in different operating modes were carried out. The value of the coolant temperature was taken as a parameter characterizing engine warm-up. In our studies, the heating of the coolant was considered complete when the temperature at the outlet of the tractor blockhead reached 85 degrees Celsius. The ambient temperature varied from plus 20 to minus 30 degrees. The effect of the load modes of its operation was taken into account on the duration of the tractor engine warming up. The results obtained show that the warm-up of the tractor engine at idle speed has a protracted nature and does not always have a positive result. The process can be intensified by operating the tractor engine under load and using an insulating cover. This reduces the duration of the warm-up process and significantly reduces the unproductive downtime of the tractor.

Construction Method of Automobile Operation Condition

The vehicle operation condition for a certain kind of vehicle is used to describe the relationship between vehicle speed and time in a specific traffic environment. The experimental group uses the acquisition device dash cam to record the driving data of a light vehicle in Shanghai for research to quickly and accurately build the operation condition of the vehicle. The information of three different periods of time for three consecutive times is also collected with the sampling frequency of 1 Hz. We use smooth processing, elimination, attribution, and sliding window method to preprocess the huge data of vehicle operating condition for studying the driving condition of automobile. A total of 724 time discontinuities are divided into three types for different processing, smooth processing with smooth function of moving average filter to eliminate the abnormal value of speed, and idle processing with long-term parking. Thereafter, the method of sliding window is used to process the idle speed data. Then, the kinematic segments are cut, and the feature values are extracted. Finally, the dimension of 13 features is reduced to four principal components. On the basis of three methods, such as contour coefficient, K-means clustering analysis method is used to continuously verify and divide the dataset into three categories, namely, stop and go, high-speed driving, and low-speed driving, which are consistent with the reality. According to the time proportion of each category, the most representative 15 segments are selected to construct the 1254 s long steam. The error rate of the result is less than 10%. The construction model of the vehicle operation condition is very detailed for the data processing process of the vehicle operation condition, and the model constantly seeks optimization on the basis of the initial clustering center. This work provides a reference for the establishment of the vehicle performance research in line with the traffic and actual operation conditions of specific cities in China.

Mathematical simulation of kinematic capabilities of mechanisms in agro-industrial complex applications

Many modern machines, including agriculture, food and mining and processing industries, use the oscillatory movement of the working body. At the same time, not only the frequency and amplitude of the oscillations, but also their shape, that is, the law of motion, are important. When solving some practical problems, it is optimal to move with distances, change the idling speed compared to the working stroke, etc. The article proposes gear eccentric system (GES) and discusses a mathematical model of kinematic capabilities for various modifications.

Enhancement of idling characteristics using multi-objective approach in light-duty diesel Vehicle fuelled with orange peel biofuel

Along with an increasing demand for an alternate source of fossil fuel, rapid urbanization has increased the motor vehicle pollutant spews in a metropolis, especially in traffic congestion or cold start condition. In reference to these situations; this research is aimed at utilizing orange peel oil (OPO) as blend fuel to mineral diesel in light-duty diesel engine and asses the output characteristics for optimizing engine fuel map under idling condition. A four-factor central composite design (CCD) approach-based response surface methodology (RSM) analysis is applied to statistically relate the effect of important input variables on key engine characteristics to achieve minimum emissions without a major compromise on the power output. From the desirability report, for orange Peel Oil (20%) blended with diesel fuel (80%) (OPO20) fuel, the optimum pilot injection timing is 210 before top dead centre (bTDC), pilot mass of 24% and apt fuel injection pressure is 500 bar while maintaining 1100 rpm as idle engine speed. While tuning the OPO20 operated engine fuel map under this optimum operating condition, a notable reduction of 34% in carbon monoxide and 36.84% reduction in smoke is observed in comparison to diesel. However, the increased mean gas temperature in-turn translated into 37.65% increase in oxides of nitrogen. As a trade-off to the reduced emissions, a 15.47% decrease in the brake thermal efficiency is observed while the specific fuel consumption also increased by 29.98% in comparison to diesel operation.

The effect of duct shape on the heat dissipation performance of ventilated clutch pressure plate

This study presents the effects of duct design on thermo-fluidic characteristics of ventilated clutch pressure plate via validated numerical model. Two different duct designs are considered. Moreover, variation of duct width and airfoil shaped duct designs are investigated. Compared to non-ventilated conventional clutch pressure plate, results show that implementing duct shape enhances the overall cooling performance by up to 154% at idle speed 550 rpm, 137% at 1200 rpm, and 142% at 2000 rpm. Once only the duct shapes are considered, it is found that the variation of inlet and outlet duct width has negligible effect on overall cooling performance. Further, radial airfoil shaped duct design shows the best cooling performance in overall among all duct shapes, and enhances the overall cooling performance by up to 11% at 550 rpm idle speed compared to non-airfoil radial duct design. In addition, implementation of ventilated design results weight reduction up to 25%. Heat transfer enhancement mechanisms clarified in the present study are helpful to motivate further innovative lightweight solutions in order to overcome the challenges related to the recent CO2 regulation for Heavy Duty Vehicles.

Effect of Confluence Geometry of Dual Exhaust System on Quietness and Power

Recently, the driving performance that maximizes driving pleasure, exhaust sound quality, and quietness have been recognized as important elements according to the demands of clients. Technology has been dramatically developed while the evaluation and improvement of the exhaust system have been attempted using various methods to meet the requirements of clients, the largest problem in designing the exhaust system is to maximize performance by forming the optimal back pressure and flow velocity and to reduce the generated noise and vibration. The objective of this study is to propose an optimal geometry of an exhaust system for sports sedans with a V6 and above engine. To achieve this, an experiment was conducted as follows. Before a prototype was fabricated, an exhaust system was designed and the fluid flow was analyzed. A pressure transducer was installed in the prototype, and the exhaust pressures on the exhaust system were measured at idle, medium and high engine speeds. Noise and vibration were also measured to analyze the impact of confluence geometry on the silence of vehicle. Finally, wheel horsepower, torque from wheels were analyzed using a chassis dynamometer to identify an output difference according to confluence chamber geometry and propose an optimal geometry.