Homogeneous charge compression ignition (HCCI) engines create a more efficient power source for either stationary power generators or automotive applications. Control of HCCI engines, however, is difficult since the ignition cannot be actuated directly. For the purpose of model-based analysis and control design, a crank-angle based HCCI engine model is developed in this paper based on experimental data from a single-cylinder engine. The zero-dimensional dynamic engine model is constructed based on conservation of mass and energy, and ideal gas law. Subsystems in this model included valve lift profile, cylinder volume, mass flow rate, intake and exhaust runner dynamics, cylinder dynamics, combustion model and heat-transfer model. Inputs to the model include engine speed, intake temperature, fueling rate, intake throttle and exhaust throttle positions.
Abstract Unintended acceleration events due to pedal misapplication have been shown to occur more frequently in older vs. younger drivers. While such occurrences are well documented, the nature of these movement errors is not well-characterized in common pedal error scenarios: namely, on-road, non-emergency stopping or slowing maneuvers. It is commonly assumed that drivers move in a ballistic or “direct hit” trajectory from the accelerator to the brake pedal. However, recent simulator studies show that drivers do not always move directly between pedals, with older drivers displaying more variable foot trajectories than younger drivers. Our study investigated pedal movement trajectories in older drivers ages 67.9 ± 5.2 years (7 males, 8 females) during on-road driving in response to variable traffic light conditions. Three different sedans and a pick-up truck were utilized.
Abstract This paper presents the physical adjustments and the incorporation of a control system to injection, ignition and throttle valve parameters for operation of a diesel engine with 100% hydrous ethanol. The control system of the aforementioned parameters integrates three dependent subsystems. The control systems of the throttle valve opening, fuel injection and ignition timings have the purpose to reduce cylinder pressure, control engine speed and the combustion process. The signals generated depend on engine speed and knock sensors, which are operated by microcontrollers programmed in Assembly and C language. The measured parameters during engine operation are relative humidity, temperature in different engine locations, fuel consumption and intake air mass flow rate. The data collected are monitored by a software developed in LabVIEW platform. The software also controls the load applied at each engine operating condition.
Abstract A low pressure exhaust gas recirculation system (LP EGR system) enables the expansion of the EGR operating area than that of the widely used high pressure EGR system. As a result, fuel consumption and emissions can be improved. In order to meet the EU 5 emissions regulations, an exhaust throttle LP EGR system was used. The EU5 vehicles developed using this system have greater merits than other vehicles. However, because the exhaust throttle LP EGR valve is installed adjacent to the after-treatment system, the material of the LP EGR valve itself must be stainless steel in order to withstand the thermal stress, consequently, the cost is increased. Therefore, in order to achieve cost rationalization for EU6 vehicles, an intake throttle LP EGR system is developed and applied to replace the exhaust throttle LP EGR system. In order to apply the intake throttle LP EGR system, the EGR valve is installed in front of the turbo charger compressor.
Torque profile control is one of required technologies for propulsion engines. A smaller parametric model is more preferable for control algorithm design and evaluation. Mean value engine torque can be obtained from throttle opening change using a transfer function. A transfer function for a turbocharged engine was investigated with thermo-dynamic equations for a turbine and a compressor and test data. A small turbocharged engine was tested to model the air transfer process. Turbine speed was measured with temperatures, pressures and air mass flow. Turbine speed response is like a first order system to air mass flow into a combustion chamber. The pressure ratio at the compressor is approximated by a curve proportional to the turbine speed square. Based on those findings, a reduced order model for describing dynamic air transfer process with a turbocharger was constructed. The proposed model is compact and suitable for engine torque control design and controller implementation.
CFD Simulation and Experimental Validation of a Throttle Body Design without Bypass for Fuel Injected Motorcycles
Increased penetration of gasoline EFI (Electronic Fuel Injection) in the Indian two wheeler commuter segment, demands simplified, but robust solutions. Freedom for the end user to adjust the idle speed with carbureted engines is considered as reference behavior. Control of idle air flow in the traditional throttle body designs is through a bypass path with either an idle speed actuator or a mechanical screw. Due to the quality of air and vented blow-by in the air path, field issues observed on most throttle body designs include a) carbon deposition influencing the air flow characteristics b) consequent effects included instability of idle speed, jamming of throttle valve or clogging of idle air control valve. One of the design measures suggested  was to introduce an idle screw on the throttle flap to retain the user experience based on the incumbent carburettor and address the carbon deposition based on the knowledge of ETB (Electronic Throttle Body).
Analysis of the Mixture Formation at Partial Load Operating Condition: The Effect of the Throttle Valve Rotational Direction
In the next incoming future the necessity of reducing the raw emissions leads to the challenge of an increment of the thermal engine efficiency. In particular it is necessary to increase the engine efficiency not only at full load but also at partial load conditions. In the open literature very few technical papers are available on the partial load conditions analysis. In the present paper the analysis of the effect of the throttle valve rotational direction on the mixture formation is analyzed. The engine was a PFI 4-valves motorcycle engine. The throttle valve opening angle was 17.2°, which lays between the very partial load and the partial load condition. The CFD code adopted for the analysis was the FIRE AVL code v. 2013.2. The exhaust, intake and compression phases till TDC were simulated: inlet/outlet boundary conditions from 1D simulations were imposed.
The Effect of the Throttle Valve Rotational Direction on the Tumble Motion at Different Partial Load Conditions
Abstract In PFI and GDI engines the tumble motion is the most important charge motion for enhancing the in-cylinder turbulence level at ignition time close to the spark plug position. In the open literature different studies were reported on the tumble motion, experimental and not. In the present paper the research activity on the tumble generation at partial load and very partial load conditions was presented. The added value of the analysis was the study of the effect of the throttle valve rotational direction on the tumble motion and the final level of turbulence at the ignition time close to the spark plug location. The focus was to determine if the throttle rotational direction was crucial for the tumble ratio and the turbulence level. The analyzed engine was a PFI 4-valves motorcycle engine. The engine geometry was formed by the intake duct and the cylinder. The CFD code was FIRE AVL code 2013.1.
Abstract Throttling loss of downsized gasoline engines is significantly smaller than that of naturally aspirated counterparts. However, even the extremely downsized gasoline engine can still suffer a relatively large throttling loss when operating under part load conditions. Various de-throttling concepts have been proposed recently, such as using a FGT or VGT turbine on the intake as a de-throttling mechanism or applying valve throttling to control the charge airflow. Although they all can adjust the mass air flow without a throttle in regular use, an extra component or complicated control strategies have to be adopted. This paper will, for the first time, propose a de-throttling concept in a twin-charged gasoline engine with minimum modification of the existing system. The research engine model which this paper is based on is a 60% downsized 2.0L four cylinder gasoline demonstrator engine with both a supercharger and turbocharger on the intake.
Abstract Cost reduction is an important development goal for small motorcycles (1). As a way to reduce costs, we have developed an electronically controlled fuel injection (hereafter FI) system without a throttle position sensor (hereafter TPS). Ordinarily, the high throttle range is controlled and computed by TPS, and the low throttle range by manifold pressure sensor (hereafter MPS). The intake airflow is estimated with consistent high precision regardless of the engine load, and the basic fuel injection is executed accordingly. Also, transient correction monitors the size of TPS changes, to inject fuel immediately when a TPS change equal to or greater than a threshold value is detected. In our development, we replaced these functions with control by MPS. For calculation of basic fuel injection quantity by MPS, we carried on the conventional method. However, MPS transient correction control had some aspects with poor tracking.
Detecting a Fully-Closed Throttle by Manifold Pressure in Fuel Injection System with Idle Speed Control
Abstract Various sensors including throttle position sensors (TPS), manifold pressure sensors (MPS), crank angle sensors, engine temperature sensors, and oxygen sensors are mounted in electronically controlled fuel injection (FI) systems to accurately regulate the air-fuel ratio according to the operating state and operating environment. Among these vehicle-mounted sensors, TPS has functions for detecting a fully-closed throttle and estimating intake air volume by the amount of throttle opening. Currently, we have conducted a study on transferring TPS functions into the MPS (manifold pressure sensor) in order to eliminate the TPS. Here we report on detecting a fully-closed throttle for achieving fuel cut control (FCC) and idle speed control (ISC) in fuel injection systems. We contrived a means for fully-closed throttle detection during ISC and controlling changes in the bypass opening during FCC in order to accurately judge each fully-closed throttle state via the manifold pressure.
The Torque from an engine is a very critical parameter which controls the drivability of the vehicle, better torque availability at Partially Open Throttle (POT) condition improves drivability at city driving condition and better torque at Wide Open Throttle (WOT) condition improves cruising at highway driving condition, conventionally engine produces better torque at one particular operating condition leaving poor drivability at others. The Torque characteristics of an engine depends upon the volumetric efficiency of the engine. The volumetric efficiency of a naturally aspirated engine can be improved by tuning the intake manifold. With an overall improvement in volumetric efficiency throughout the engine operating conditions better torque curve can be achieved, which facilitates improved drivability.
A Location-Aware Adaptive Vehicle Dynamics System (LAAVDS) is developed to assist the driver in maintaining vehicle handling capabilities through various driving maneuvers. An Intervention Strategy uses a novel measure of handling capability, the Performance Margin, to assess the need to intervene. The driver's commands are modulated to affect desired changes to the Performance Margin in a manner that is minimally intrusive to the driver's control authority. Real-time implementation requires the development of computationally efficient predictive vehicle models which is the focus of this work. This work develops one means to alter the future vehicle states: modulating the driver's throttle commands. First, changes to the longitudinal force are translated to changes in engine torque based on the current operating state (torque and speed) of the engine.
Recently, there have been many reports about developing control systems that actuate engines and brakes based on friction circle. We are researching the control system for motorcycles, which adds the return torque of throttle grip based on it for informing the limit of tire grip on the driving wheel. This throttle grip is a haptic display, offers haptic signals by controlling the motor connected to the throttle grip as a HMI. From the results of riding tests, the system was found helpful for riders to control the throttle grip as well as feeling easy about knowing the limit of tire grip. But it is known that the friction circle of a driving wheel depends on the normal force which changes by the gradient of road, acceleration and so on. The compensated control for changing the normal force by gradient was made to improve the throttle grip control system.
Honda developed a new generation 1.6L diesel engine as a part of technologies for high driving performance and good fuel economy. This new engine is equipped on Civic (C Segment, 5 doors), launched as a new European model in 2013. This engine has some technologies achieving both good fuel economy and low emission, and met Euro5 emission regulation. And the Civic achieved CO2emission of 94 g/km in NEDC, a reduction of 14.5% in CO2 emission against the previous diesel engine of Honda.  This engine has the dual EGR system composed of HP-EGR and LP-EGR, one of the technologies introduced to increase fuel efficiency. In this paper, some issues for the dual EGR system control and countermeasures for them will be described. In order to control each EGR mass flow, two or more valves (HP-EGR valve, LP-EGR valve and intake throttle) should be regulated cooperatively.
Investigations were conducted on how to improve vehicle performance by improving throttle response. A method for improving throttle response was to reduce the rotating and reciprocating mass in the engine. Two engines, which only differed in the amount of rotating and reciprocating mass, were investigated. Based on tests on a chassis dynamometer, it was observed that there was an 18% faster throttle response for the engine possessing the lower amount of rotating and reciprocating mass.
Recently, there have been many reports about development of Human Machine Interface (HMI) which used a visual or auditory display to improve driver assist. For a motorcycle, it is suitable to use a haptic display for rider assist, since there are many disturbances in open-air situation such as sunshine and surrounding noise. Therefore, a test vehicle based on a large motorcycle equipped with the haptic throttle grip that is connected to a motor by gear, an original ECU to control the motor, and a lean angle sensor to calculate the lateral force of the motorcycle was developed. To inform surplus driving force warning, the throttle grip, a haptic display outputs additional return torque estimated by the friction circle and ellipse with the lateral force of the motorcycle.
The Effect of Modifying Throttle Body for Gas Injectors on Engine Performance and Emissions of SI Automotive Engine
This study was carried out to evaluate the variation in performance and emission characteristics of a multi cylinder Multi-point Fuel Injection (MPFI) automotive Spark Ignition (SI) engine after incorporating an additional manifold for gas injectors to throttle body. To install gas injectors for Compressed Natural Gas (CNG)/Hydrogen-CNG (HCNG) operation throttle body of the engine was modified using a novel manifold. The performance and emission characteristics of the existing throttle body and the new throttle body configuration were evaluated. The parameters studied were Manifold Air Pressure (MAP), Torque and Emissions (HC, CO, CO2, and NOx) for gasoline operation. The influence of installing new manifold on these parameters was evaluated. It was important to evaluate the degree of variation of the parameters on the gasoline operation so that the addition of new manifold for gas operation could be validated. The measurement was carried out at wide open throttle.
Improvement of Part Throttle Performance of Carburetor Used in a Two Wheeler Four Stroke Single Cylinder Engine
With the introduction of stringent emission norms for two wheeler applications, and need to reduce green house gases emission, it is a challenging task to improve the performance of the engine, especially at part throttle conditions. The typical drawback of spark ignition engine is poor part throttle performance and the Indian driving cycle (IDC) predominantly covers these part throttle operations. Contrary to popular belief, carbureted two wheelers with engine capacity up to 250cc are able to meet regulation Euro III with add-ons like secondary valve and catalyst. Vehicles with EFI systems are more expensive and they are not able to provide any fuel economy benefit or improvement in drivability. Under these circumstances, carburetor designers are working continuously to improve its performance. In order to improve the performance, optimization of slow speed to high speed fueling circuit dividing ratio is of immense importance.
The need to improve fuel consumption by saving the weights of automobile parts is growing from the viewpoint of global warming mitigation. In the case of a throttle body for controlling the air flow volume into an engine, it is important to achieve a high dimensional accuracy of the valve-bore gap in the state of closed valve. In fact, most throttle bodies are made of precision-machined metal. Therefore, resin throttle bodies are drawing attention as a lightweight alternate. However, in comparison with metal throttle bodies, resin throttle bodies have two potential disadvantages that should be solved prior to productization. The first one is greater air leakage in the state of closed valve, and the second one is smaller heat conduction for unfreezing the valve in a frigid climate. We have developed an electronic resin throttle body that has overcome the above-mentioned disadvantages.
Reducing Throttle Losses Using Variable Geometry Turbine (VGT) in a Heavy-Duty Spark-Ignited Natural Gas Engine
Abstract Stoichiometric operation of Spark Ignited (SI) Heavy Duty Natural Gas (HDNG) engines with a three way catalyst results in very low emissions however they suffer from bad gas-exchange efficiency due to use of throttle which results in high throttling losses. Variable Geometry Turbine (VGT) is a good practice to reduce throttling losses in a certain operating region of the engine. VTG technology is extensively used in diesel engines; it is very much ignored in gasoline engines however it is possible and advantageous to be used on HDNG engine due to their relatively low exhaust gas temperature. Exhaust gas temperatures in HDNG engines are low enough (lower than 760 degree Celsius) and tolerable for VGT material. Traditionally HDNG are equipped with a turbocharger with waste-gate but it is easy and simple to replace the by-pass turbocharger with a well-matched VGT.
The automotive industry is currently facing the challenge of significantly stringent requirements regarding CO₂ emission and fuel economy coming from both legislations and customer demand. Advanced engine technologies play a vital role for downsizing of gasoline engine. The development of key design technologies for high efficiency gasoline engines is required for the improvement of competitive power in the global automobile industry. This paper focused on effect of geometry of intake manifold of gas exchange process and consequently the performance of the engine. Specially, the optimal design technologies for the intake manifold and intake port shape must be established for high performance, increasingly stringent fuel economy and emission regulations. Space in vehicle or packaging constraints and cost are also important factors while consideration of the design.
Comparative Investigation of Throttle-free Load Control on a 2.0 l Four Cylinder Turbocharged Gasoline Engine with Port and Direct Fuel Injection
A 2.0 l turbocharged gasoline engine with port injection and a comparable turbocharged gasoline engine with direct injection have been investigated on a test bench at Kaiserslautern Technical University. Both engines were driven with throttle-free load control by fully mechanically variable valve actuation (CVVL). The basic series-production turbocharged engine in this comparison is the version with direct injection without the fully variable valve train. The focuses of the fired tests were investigation of the fuel consumption at part load and of maximum torque behavior at low engine speeds at full load. In both engine modes, use of fully variable valve actuation shows improvements compared with the turbocharged engine versions without CVVL. Better turbocharger response enabled the torque behavior to be optimized.
Engine Electronic Throttle Control (ETC) systems are gaining success in high volume applications. This system helps to improve overall engine and vehicle performance, as well as facilitate the function integration of related control features. The requirement for an ETC system is that it fulfills the commanded throttle plate opening as quickly and accurately as possible. Because of nonlinearity of the electronic throttle system, gain-scheduled control is often used. A method to automatically tune the control for each operating region is needed. In this paper the engine electronic throttle is considered as having dominant linear dynamics for each operating region. A Two-Degree-of-Freedom (2-DOF) PID controller and a method of using Model Reference Adaptive Control (MRAC) algorithm to automatically tune the PID control gains are designed.
It has been clearly demonstrated separately, that the application of both Dual Cam Phasers (DCP) and External Cooled EGR systems are highly beneficial to improving the efficiency of highly-boosted GDI engines. DCP systems can optimize the volumetric efficiency at WOT conditions, improve boost and transient response at low engine speeds, and provide internal EGR at low RPM part-load conditions. External cooled EGR has been demonstrated to dramatically improve the fuel consumption, lower turbine inlet temperature, and improve emissions at high power conditions. In previous investigations by the BorgWarner Engine Systems Group, we showed that full engine speed/load range EGR coverage can be obtained by combining High Pressure Loop and Low Pressure Loop external EGR systems with a DCP strategy.
This work involved study of the effects of alcohol blends on combustion, fuel economy and emissions in a single cylinder research engine equipped with a mechanical fully variable valvetrain on the inlet and variable valve timing on the exhaust. A number of splash blends of gasoline, iso-octane, ethanol and butanol were examined during port fuel injected early inlet valve closing operation, both with and without variable valve timing. Under low valve overlap conditions, it was apparent that the inlet valve durations/lifts required for full unthrottled operation were remarkably similar for the wide range of blends studied. However, with high valve overlap differences in burning velocities and internal EGR tolerances warranted changes in these valve settings.
A patent pending engine control system with torque sensor feedback is described. Upon detecting a loss in traction by means of a torque sensor, engine torque is adjusted via throttle paving the way for improved traction and enhanced stability. The throttle is reduced to a calculated value using engine characteristics, the torque sensor measurement and non-slipping wheel speed information. The advantages of the powertrain torque sensing as opposed to speed sensing are demonstrated thru a case study of a RWD SUV with an open rear differential. Simulations are used to prove the concept while the bandwidths of a number of physical systems contributing to the overall response time are ignored. Therefore the data provided in this paper should be treated relatively comparing speed sensors versus torque sensors. There are a number of engine torque reduction methods faster than throttle control such as spark retard and fuel shutoff.
For the throttle bodies for sport motorcycles, there is a need for a design giving importance to drivability and precise control. At the same time, various devices such as idle control and duct control are necessary in order to conform to recent environmental regulations. However, these added functions lead to an increase in the number of components, thus leading to disadvantages in both cost and weight. Therefore we have developed a throttle body where DBW (Drive By Wire) has been used to consolidate such parts, and functions. For the drive actuator, a modified actuator device from a passenger car DBW system was incorporated into a multi-cylinder link structure. In addition, specifications such as the gear ratios and the operation torque were optimized in order to satisfy the operability required for motorcycles.
In recent years, even motorcycles impose demands for engine power controls that are more flexible and precise. The Electronic Throttle Control (ETC) system is one of the methods that addresses this need. However, the most important issue facing the installation of the ETC system on the motorcycle is handling failures. To avoid this problem, we developed an ETC system for motorcycles that can properly effect engine power control in case of a failure. This ETC system contains in duplicate the major components to detect failures and switch to a failure mode properly. To effect control that is optimally suited to the type of failure, this system switches between three types of failure modes. These failure modes are designed to minimize risks in case of a failure and maximize the operational capability while the rider is on the way to have the motorcycle repaired.
In the port injected Spark Ignition (SI) engine, the single greatest part load efficiency reducing factor are energy losses over the throttle valve. The need for this throttle valve arises from the fact that engine power is controlled by the amount of air in the cylinders, since combustion occurs stoichiometrically in this type of engine. In WEDACS (Waste Energy Driven Air Conditioning System), a technology patented by the Eindhoven University of Technology, the throttle valve is replaced by a turbine-generator combination. The turbine is used to control engine power. Throttling losses are recovered by the turbine and converted to electrical energy. Additionally, when air expands in the turbine, its temperature decreases and it can be used to cool air conditioning fluid. As a result, load of the alternator and air conditioning compressor on the engine is decreased or even eliminated, which increases overall engine efficiency.