Browse Topic: Electronic throttle control
In this paper, the Artificial Neural Network (ANN) control strategy based on the Nonlinear Auto Regressive Moving Average-Level 2 (NARMA-L2) technique has been used for tracking control of an electronic throttle body. The NARMA-L2 nonlinear plant model is first identified offline by training using a set of input-output data pairs measured at different operating conditions. This data was collected from an actual operation of the throttle body running in a closed-loop control system on a prototype vehicle. The identified NARMA-L2 plant model was then inverted and used to force the throttle output position to approximately track any reference inputs with multiple set-point changes at different operating conditions. The NARMA-L2 model was reconfigured to be an equivalent model of a feed-forward controller that can cancel not only the actual dynamic behavior of the throttle body but also the nonlinearity effects. This type of controller has great potential to overcome the difficulty of developing an inverse dynamic model of the throttle body [1] and has the ability to compensate any un-modeled nonlinear dynamic changes that may be excited due to environmental changes. These changes can include load, temperature, humidity, and external disturbances with noise effects that may be introduced into the closed-loop control of the throttle body during real time operation in the vehicle. The resulting closed loop control system used the NARMA-L2 architecture that have a multilayer perceptron neural network structure with the dynamic back-propagation algorithm becomes an implicit algebraic model that perfectly tracks any multiple set-point changes at different operating conditions. Testing results from real time implementation are provided to illustrate the new controller performance for tracking controls during actual operation on a prototype vehicle. The identified NARMA-L2 neuro-controller shows more robustness and better performs as compared to other controllers developed in previous work [1-3]. * This work was done while the author was at IAV Automotive Engineering Inc, 15620 Technology Drive, Northville, MI 48168. † Currently working with MAHLE Powertrain LLC, 14900 GalleonCourt, Plymouth, MI 48170.
The development of intelligent transportation improves road efficiency, reduces automobile energy consumption, and improves driving safety. The core of intelligent transportation is the two-way information interaction between vehicles and the road environment. At present, road environmental information can flow to the vehicle, while the vehicle’s information rarely flows to the outside world. The electronic throttle and electronic braking systems of some vehicles use sensors to get the state of the accelerator and brake pedal, which can be transmitted to the outside environment through technologies such as the Internet of Vehicles. But the Internet of Vehicles technology has not been widely used, and it relies on signal sources, which is a passive way of information acquisition. In this paper, an active identification method is proposed to get the vehicle pedal on-off state as well as the driver’s operation behavior through existing traffic facilities. The research object is the commercial vehicles driving on expressways. Vehicle speed is acquired by the camera, and specific vehicle models are identified by the camera to get the relevant vehicle parameters from the vehicle model database. Combined with road environment data, the pedal on-off state will be calculated by the vehicle dynamics model. The research results show that the judgment accuracy of the pedal opening and closing state is high, and the errors are generated at the time of the pedal opening and closing state transition, and the maximum error is 0.4 s. This study provides a new method for the outside access to vehicle longitudinal operation information in the intelligent transportation system and provides a backup scheme for the information interaction of the Internet of Vehicles, which can provide a reference for the determination of traffic accident liability.
Efficiency testing of hybrid-electric vehicles is challenging, because small run-to-run differences in pedal application can change when the engine fires or the when the friction brakes supplement regenerative braking, dramatically affecting fuel use or energy regeneration. Electronic accelerator control has existed for years, thanks to the popularity of throttle-by-wire (TBW). Electronic braking control is less mature, since most vehicles don’t use brake-by-wire (BBW). Computer braking control on a chassis dynamometer typically uses a mechanical actuator (which may suffer backlash or misalignment) or braking the dynamometer rather than the vehicle (which doesn’t yield regeneration). The growth of electrification and autonomy provides the means to implement electronic brake control. Electrified vehicles use BBW to control the split between friction and regenerative braking. Automated features, e.g. adaptive cruise control, require BBW to actuate the brakes without pedal input. We present a system for computer control of brake and accelerator inputs on a TBW- and BBW-equipped vehicle. The system injects analog signals into the vehicle’s wiring harness, bypassing the pedals and obviating mechanical actuation and brake-by-dyno. The system combines feedforward control based on recorded human pedal application with feedback control based on human-driven speed. This combination produces repeatable driving, enabling precise measurement of the impact (e.g. fuel or battery use) of small changes to the powertrain (e.g. engine calibration or lubricant) or test cycle (e.g. speed or grade). The system’s J2951-defined energy-efficiency rating and absolute speed-change rating were more consistent than a human’s by factors of 6.63 and 4.10, respectively. The effect of braking intensity on braking regeneration is quantified using the system.
Electronic throttle body (ETB) is commonly employed in an intake manifold of a spark ignition engine to vary the airflow quantity by adjusting the throttle valve in it. The actual position of the throttle valve is measured by means of a dual throttle position sensor (TPS) and the signal is feedback into the control unit for accomplishing the closed loop control in order handle the nonlinearities due to friction, limp-home position, aging, parameter variations. This work aims presents a neural networks based novel virtual sensor for the estimation of throttle valve position in the electronic throttle body. Proposed neural network model estimates the actual throttle position using three inputs such as reference throttle angle, angular error and the motor current. In the present work, the dynamic model of the electronic throttle body is used to calculate the current consumed by the motor for corresponding throttle valve movement. Proposed virtual sensor is tested for the sinusoidal and random driving cycle throttle angle input using a Bosch DVE5 electronic throttle body. Estimated throttle valve angle using the proposed neural network is found to closely follow the measured throttle valve angle using hardware TPS. Experimental results exhibit the accurate tracking capacity of the proposed virtual sensor for the throttle valve estimation in the event of hardware throttle sensor failure and it can be useful as an added redundancy in the electronic throttle control system.
The introduction of new emission legislation and the demand of increased power for small two-wheelers lead to an increase of technical requirements. Especially for single cylinder engines with high compression ratio the transient behavior close to idling is challenging. The demand for two-wheeler specific responsiveness of the vehicle requires low overall rotational inertia as well as small intake manifold volumes. The combination with high compression ratio can lead to a stalling of the engine if the throttle opens and closes very quickly in idle operation. The fast opening and closing of the throttle is called a throttle blip. Fast, in this context, means that the blipping event can occur in one to two working cycles. Previous work was focused on the development of a procedure to apply reproducible blipping events to a vehicle in order to derive a deeper physical understanding of the stalling events. The corresponding investigations were performed on a motorcycle with a mechanical throttle body. Based on this the present paper is focused on a comparison to a motorcycle with the same base engine and boundary conditions but with electronic throttle control. The main targets are to reproduce the blip events based on the previous work and to evaluate whether any differences can be observed in the physical root causes, which can lead to a stalling of the engine. In the course of the examination process, the previously introduced systematic of blip stall mechanisms is refined. Therefore, thousands of blip events with defined start position within the working cycle are applied, automatically evaluated and categorized. The previous work showed a significant influence of the idle speed on the probability of a stall occurrence for a throttle blip. It was shown that a single retarded combustion process or misfire could lead to a stalling of the engine at a sudden throttle opening. The only counter measure in that case for a system with mechanical throttle body is an increased idle speed. Furthermore, it was shown that the additional pressure build-up caused by early ignition angles is increasing the stall probability. All measured stall events have been grouped into different stall modes, which are described by typical patterns of engine speed and intake pressure during and after the blip event.
Electronic throttle control is extensively preferred to vary the air intake in the engine manifold for regulating the torque in order to obtain the better vehicle response, high performance in terms of improving the fuel economy and trim down the emissions of the spark ignition engines. For such type of the engine control systems the throttle angle is estimation is accomplished either by pedal follower or torque based method. This work aims to develop a throttle opening angle estimation strategy in a closed loop manner using fuzzy logic approach by considering real time internal system and driver torque demands for controlling the SI engine. In present work the torque demand from internal system such as catalyst heating, cold start assist and battery voltage compensation is estimated using fuzzy logic strategy. Such intelligent system aims to replace the lookup tables associated with those systems and reduces the calibration effort. For the estimated throttle angle the electronic throttle body is evaluated in an engine test bed simulation on Matlab Simulink platform for the various accelerator pedal inputs conditions. Also, the external or auxiliary torque demand input given in the form of ramp signal and assumed torque cycle. The outcome curves based on simulation for engine torque, speed and power are compared against the open loop method. The simulation result of the proposed approach shows betterment than the existing method.. Angular error of the proposed closed loop method is in lower range of 5.3 deg and 4.1 deg for ramp and step based driving cycle inputs respectively. The error value for open loop method is in the higher side of 7.4 deg and 6.7 deg.
When Volkswagen fell afoul of U.S. and European emissions rules, it effectively stripped the U.S. car market of small turbodiesels for passenger vehicles. While Mazda is still certifying its 2.2-L Skyactiv-D for the CX-5 (now expected on sale in spring 2018), General Motors is ready to fill the void. Its all-new 1.6-L turbodiesel, a $2,200 option for the 2018 Chevrolet Cruze and Equinox and GMC Terrain, was engineered four years ago in Italy, is built in Hungary and was calibrated in Detroit for the hitherto-abandoned market. Fuel economy, with highway numbers particularly impressive, are diesel strong points. The Cruze diesel is EPA highway-rated at 52 mpg with the GM-Ford joint-venture 9T50 9-speed automatic transmission. The Equinox is rated at 39 mpg for front-drive, 38 mpg for all-wheel drive using GM's 6-speed automatic. Equinox' greater curb weight precludes any real-world economy advantage for the 9-speed over the 6-speed transmission.
CNG has recently seen increased penetration within the automotive industry. Due to recent sanctions on diesel fuelled vehicles, manufactures have again shifted their attention to natural gas as a suitable alternative. Turbocharging of SI engines has seen widespread application due to its benefit in terms of engine downsizing and increasing engine performance [1]. This paper discusses the methodology involved in development of a multi cylinder turbocharged natural gas engine from an existing diesel engine. Various parameters such as valve timing, intake volume, runner length, etc. were studied using 1D simulation tool GT power and based on their results an optimized configuration was selected and a proto engine was built. Electronic throttle body was used to give better transient performance and emission control. Turbocharger selection and its location plays a critical role. Turbocharger Wastegate actuator trials were conducted to select optimum actuator to restrict boost enough to meet power target. Various engine related MAP like main lambda, volumetric efficiency, MBT timing, Primary ignition timing, etc. were calibrated and saved in EMS. The full load curve was calibrated using EMS to meet performance target of 85 kW rated power and 285 Nm max torque. Further, through precise calibration of various ECU tables the engine managed to meet BS IV emission norms.
An applicable and comprehensive control strategy of a natural gas/diesel dual fuel engine is presented in this paper. The dual fuel engine is converted from a conventional mechanical pump, turbo charged, heavy duty diesel engine. In the dual fuel mode, the pedal position is explained as demanded total fuel quantity, the quantity of pilot diesel and natural gas are calculated in order to provide the equal energy with the original diesel engine at the same operation condition, the proportion of the natural gas is primarily determined by the load rate and the speed of the engine. When the engine is working under light or moderate load, the intake air is throttled in order to improve the brake mean effective pressure and reduce the hydrocarbon emissions of the dual fuel engine, according to target excess air ratio and the quantities of the two fuels, the desired air mass per cycle can be obtained. After that a mean value model based feedforward control is adopted to calculate the electronic throttle position, with a universal exhaust gas oxygen sensor, a proportional-integral controller is designed, therefore feedback control is introduced to the air/fuel ratio control system to enhance its accuracy and robustness. Verification test results show that: the engine which employs the control strategy in this paper can work stably and reliably with less calibration data; the air/fuel ratio is regulated accurately and quickly; dual fuel engine has better fuel economy even though its brake thermal efficiency is lower due to the comparatively low price of natural gas; intake throttling has significant effect on improving the economy and hydrocarbon emission of the dual fuel engine under light and moderate load.
Range Extended Electric Vehicles (REEVs) are gaining popularity due to their simplicity, reduced emissions and fuel consumption when compared to parallel or series/parallel hybrid vehicles. The range extender internal combustion engine (ICE) can be optimised to a number of steady state points which offers significant improvement in overall exhaust emissions. One of the key challenges in such vehicles is to reduce the overall powertrain costs, and OEMs providing REEVs such as the BMW i3 have included the range extender as an optional extra due to increasing costs on the overall vehicle price. This paper discusses the development of a low cost Auxiliary Power Unit (APU) of c.25 kW for a range extender application utilising a 624 cc two cylinder automotive gasoline engine. Changes to the base engine are limited to those required for range extender development purposes and include prototype control system, electronic throttle, redesigned manifolds and calibration on European grade fuel. Modifications to the intake/exhaust manifolds were initially modelled using GT-Power and validated by engine tests. These modifications improved the engine torque in the APU planned operating range, and the new control system achieved improved BSFC up to 4000 RPM with European grade fuel. The use of European grade fuel also allowed operation at lambda 1 across a marginally wider portion of the engine operating range to improve fuel economy. Further modifications include replacing the mechanical coolant pump with an electric pump to reduce engine warmup duration and improve fuel economy.
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 [1] 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). The primary objective of this investigation was to validate this assumption through CFD (Computational Fluid Dynamics) analysis backed by vehicle trials. In CFD, carbon deposition can be characterized as a function of velocity and pressure. This phenomenon was used to simulate air flow in the throttle body with and without bypass path and compared against the experimental results. Further, these configurations were subjected to real world driving conditions to evaluate the effect on carbon deposition phenomenon. The simulation showed a channeled air flow with the maximum velocity of 353m/s (which is greater than sonic velocity) for throttle body without bypass path. The simulation and experimental results for air mass flow had close agreement with <8% deviation over the entire range of throttle opening. The results from vehicle trials indicated reduced rate of carbon deposition when observed at frequent intervals during the trials. Learning from the iterative steps, vehicle validation results and combination of smart software algorithm enabled a robust throttle body design.
Last mile transportation is an important supply chain and transportation requirement for the movement of people and goods from a transport hub to a final destination in that area. In India this requirement is largely met by 3 wheelers and small 4 wheelers (below 1 ton payload). Greaves cotton Ltd. (GCL) has played an important role for last mile transportation solutions in India by developing suitable engines for the above category vehicles. GCL is already supplying single cylinder air cooled 400 cc diesel / CNG, 435 cc & 510 cc diesel and 510 cc water cooled CNG BSIII engines for 3 wheeler applications. Single cylinder water cooled 510 cc and 611 cc BSIII diesel engines are being supplied for small commercial 4 wheeler applications. In India, BSIV emission norms are in place since April 2010 in metro cities for 4 wheelers. CNG network is well established in most of these cities. Hence to serve this market, the CNG engine variant development of the 611 cc diesel BSIII engine was initiated. At present ECU based close loop CNG port injection technology is used in multi-cylinders engines for car and commercial vehicle applications. On the other hand, single cylinder engines with venturi based open / close loop systems are being used for 3 wheeler vehicles. This is a first of its kind of efforts which combines the ECU based port injection as well as electronic throttle body (ETB) technology and various sensors for a single cylinder engine to make it suitable for small 4 wheeler applications. This paper describes development and performance of the 611 cc, single cylinder, naturally aspirated, 4-stroke, water cooled dedicated CNG engine with port injection close loop fuel system. The base direct injection diesel engine was re-designed to operate on CNG with advance electronics controls. The engine variables optimised to convert the base diesel engine to operate on CNG were compression ratio, combustion chamber and intake port. Intake manifold was specially designed to integrate CNG injector, TMAP sensor and electronic throttle body. Crank sensor with tone wheel was employed to give TDC and engine speed inputs to the ECU. Lambda sensor was installed on the exhaust manifold for close loop control. This engine with drive by wire technology is not only capable of meeting the stringent BS-IV (4W) emission norms along with IOBD-II compliance but also gives superior performance w.r.t. drivability and startability. The development is already completed and now the engine is ready for the serial production.
In ISO 26262, the top-level safety goals are derived using the Hazard Analysis and Risk Assessment. Functional safety requirements (FSRs) are then derived from these safety goals in the concept phase (ISO 26262-3:2011). The standard does not call out a specific method to develop these FSRs from safety goals. However, ISO 26262-8:2011, Clause 6, does establish requirements to ensure consistent management and correct specification of safety requirements with respect to their attributes and characteristics throughout the safety lifecycle. Hence, there are expectations on the part of system engineers to bridge this gap. The method proposed in this paper utilizes concepts from process modeling to ensure the completeness of these requirements, eliminate any external inconsistencies between them and improve verifiability. The goals of process modeling are to understand the current state of the process in detail, define the desired state of the process and implement techniques to change the state. The process model variables provide the appropriate context needed to define these states. These principles are commonly adopted in the fields of software development and chemical engineering. They are also being used to improve safety in aviation and industrial operations with some success. In an ISO 26262-based product development, process modeling can help define all the safety-relevant attributes of a system and analyze them. With this information, the functional safety requirements can be written with a high level of rigor. Electronic Throttle Control is used in this paper as an example to illustrate the advantages of the proposed method.
Homogeneous Charge Compression Ignition (HCCI) and Spark Ignition (SI) dual-mode operation provides a practical solution to apply HCCI combustion in gasoline engines. However, the different requirements of air-fuel ratio and EGR ratio between HCCI combustion and SI combustion results in enormous control challenges in HCCI/SI mode switch. In this paper, HCCI combustion was achieved in a four-cylinder gasoline direct injection engine without knock and misfire using close-loop control by knock index. Assisted Spark Stratified Compression Ignition (ASSCI) combustion was obtained stably at medium-high load. ASSCI combustion exhibits two-stage heat release with initial flame propagation and controlled auto-ignition. The knock index of ASSCI combustion is less than HCCI combustion due to the lower pressure rise rate. The stable operation range of stoichiometric ASSCI combustion is from 0.35MPa to 0.65MPa Indicated Mean Effective Pressure (IMEP), which is higher than normal gasoline HCCI combustion. Therefore, ASSCI mode naturally fills the gap between HCCI at low load and SI combustion at high load in gasoline HCCI engine. Applying ASSCI strategy can effectively reduce the frequency of engine combustion mode switch. HCCI/SI and ASSCI/SI combustion mode switch were investigated and compared in a four-cylinder GDI engine which was equipped with dual VVT (intake and exhaust), two-stage cam-profile system (CPS) and electronic throttle control (ETC). Experimental results indicated that, fuel injection in compression stroke in ASSCI mode can avoid the misfire and improve stability of switching process without the requirement of changing control variables such as throttle, CPS and injection strategy simultaneously. Meanwhile, ASSCI combustion mode can extend the load range of the compression ignition (CI). Stable HCCI/ASSCI switch was achieved by adjusting s negative valve overlap (NVO) duration only. It is therefore concluded that the switch control strategy of ASSCI/SI combustion was optimized by stoichiometric operation before/after switch and the robust combustion switch was achieved.
Clean snowmobile technology has been developed and applied to a commercially available two cylinder, four-stroke snowmobile. The goals of this effort included reducing exhaust and noise emissions to levels below the U.S National Parks Service (NPS) Best Available Technology (BAT) standard while increasing vehicle dynamic performance with a 50 percent peak power increase over the original equipment version. Engine thermal efficiency has been increased through Late Intake Valve Closure (LIVC) valve timing modification for Miller cycle operation, while high load power was increased through the implementation of a turbocharger and variable electronic boost control. An electronic throttle was also implemented in combination with a “performance/economy” mode switch to limit speed and increase fuel efficiency per the rider's demands. Additionally, a new exhaust system featuring a three-way catalytic converter and a simple, lightweight muffler utilizing a passive acoustic valve has been developed to reduce chemical and noise emissions. This snowmobile was modified to run the full range of ethanol-blended fuels using an affordable flex-fuel sensor and custom controls, including closed-loop wideband exhaust oxygen feedback. Excellent fuel efficiency was achieved with the lean-burn Miller cycle powertrain in addition to an exhaust emissions improvement of 13 percent from the original equipment version.
THE ADOPTION OF A SINGLE-CYLINDER ENGINE, INSTEAD OF THE MORE POWERFUL INLINE FOUR CYLINDER, REQUIRED A MUCH BIGGER EFFORT FOR GETTING AN ACCEPTABLE LEVEL OF POWER. FORMULA SAE AND ITS EQUIVALENT in the U.K. named Formula Student are competitions among university students who have to design, build, and race a car complying with specific rules issued by SAE International. The final classification of the competition derives from the sum of the scores achieved in the single events, which are divided into statics (design: 150 points at maximum, cost: 100 points, and presentation: 75 points) and dynamics (acceleration: 75 points, skid pad: 50 points, and endurance: 400 points). As far as the engine is concerned, the technical regulations require one or more four-stroke engines running on gasoline or E85 with a total displacement not exceeding 610 cm3, and the air for all engines must pass through a single air intake restrictor. This restrictor is circular in shape and placed between the throttle and the engine(s). The maximum restrictor diameter is 20 mm (0.79 in) for gasoline fueled cars and 19 mm (0.75 in) for E85. Any device that has the ability to throttle the engine downstream of the restrictor is prohibited.
This paper is an introduction to the opportunities, challenges and technical solutions chosen for implementation of an electronic throttle control (ETC) system on a 50cc 2-stroke scooter. The paper outlines the selection of the ETC motor and the choice of the throttle position sensing (TPS) system along with the development of a new twin sensor throttle demand (TDS) twist grip, and briefly describes the benefits achieved in fuel economy, electronic vehicle speed control, improved start-up and idle stability. The ETC software operational strategy; including start flare, idle speed control and vehicle speed control are presented as real world strategies to achieve 22% improvements in fuel economy and accurate electronic vehicle speed control.
The global challenges for cleaner engine technology place a heavy burden on electronic control. Creative technology such as direct injection and throttle by wire create more powerful and more fuel efficient engines with lower emissions. While the majority of this type of technology would be considered evolutionary from the base electronic fuel injection (EFI) system, production engine technology can only be realized with modern system on a chip technology designed specifically for the automotive market. As the future of the global auto industry pushes beyond the Ultra-low Emission Vehicle (ULEV) and European Union Regulation 715/2007(EURO V) limits, this burden of increasingly complex electronic control is being transferred to the to the small engine market. Here, tens of millions of one and two-cylinder engines have almost no electronic content yet face emissions challenges in 2010 and beyond requiring advanced control techniques that can only be enabled by highly integrated, specialized electronics. Electrical systems incorporating the right amount of leading automotive technology are essential to the successful adoption of new electronics for small engine based products. However, these systems cannot simply be scaled from automotive designs. A combination of specialized components and fundamental technology must meet stringent cost targets to prevent a small engine based product from losing its positioning in the market due to the added cost. At the center of this problem is the principal component of an EFI system, the electronic control unit (ECU).
The world's first Variable Cylinder Management (VCM) system for large motorcycles, which will achieve both high power and low fuel consumption, has been developed. The system uses a mass production in-line four-cylinder engine which has a displacement of 1137 cm₃ as the base engine. The VCM system is capable of increasing and decreasing the number of working cylinders between 2-cylinder, 3-cylinder and 4-cylinder operations by modifying some parts of the base engine. Utilizing throttle valves installed on each cylinder, the throttle valves for continuously operating the regularly working cylinders and the on-demand working cylinders are controlled by three motors, which divide them into three independent lines. In order to improve fuel consumption by reducing the pumping loss of the non-working cylinders, the engine is equipped with hydraulically operated intake and exhaust valve deactivating mechanisms. It is very important for the posture control of the moving motorcycle to prevent abrupt changes of engine power output when the number of working cylinders is changed. In order to prevent such abrupt changes, the newly developed VCM system controls engine power output using the harmonized control of the three-system-independent Throttle-by-Wire (TBW) and the intake and exhaust valve deactivating system. Also, the fuel consumption in New European Driving Cycle (NEDC) mode is improved by approximately 46% as compared with the base motorcycle while clearing the EURO3 exhaust emission regulation values. Power output characteristics equivalent to those of the base engine are achieved. In this paper, the outline of the VCM system, the effective way of reducing output change when switching the number of working cylinders, and the effects of the improvement in fuel consumption are described.
Most times in ECU system function testing, the sensor input signals are directly set to a known value in order to drive the corresponding software variable to within a range of an expected value. This works only if the transfer function from the physical signal input to the software variable is well defined such as the measurement on MAP, A/C pressure, etc. Nevertheless, there are times the transfer function is not clearly defined and it is difficult to drive the software variable to an expected value. One example is throttle position sensor (TPS) test in an electronic throttle control (ETC) system, where TPS is not directly driven by the driver accelerator pedal sensor (APS) and it is very difficult to get TPS to an expected range by only changing APS. This paper introduces a method to use feedback in an HIL based ECU testing system to control outputs to an expected range. In this case study, the signal to be controlled is connected back to the HIL system to provide feedback. The error between the target and the actual signal is used in a PID control system to adjust the input signal dynamically and keep the signal to be controlled within the targeted range. Two different feedback methods, namely hardware feedback by physically connecting the signal to be controlled to HIL simulator and software feedback by reading back the software variable to be controlled through ASAP3 protocol between the HIL simulator and ECU instrumentation tool, are evaluated.
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. With this approach, control performance enhancement from initial control settings can be realized with closed loop testing, without the need of a plant model. Control gains that give good performance can be obtained quickly for each operating region of the system. The designed control and automatic tuning algorithm is implemented on a rapid prototyping setup and the application results show the effectiveness of the method.
Honda R&D has developed a throttle-by-wire (TBW) system that meets the needs of motorcycles where the attitude of the vehicle body is controlled by operation of the throttle. To gain high response and following for the throttle valve, we employed a new adaptive control algorithm. The newly developed system has an idling combustion stabilization function and a three-dimensional control function for the throttle-opening map based on running gear and engine speed. With those functions, we improved the controllability of the motorcycle, especially for small throttle openings. Furthermore, we improved the feeling of the limiter control used in maximum-speed limitation. For the overall system, intake system related devices are consolidated to improve the layout flexibility and expand the mounting options on the motorcycle.
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. Thus, by creating a fail-safe system that effects engine power control, while keeping the vehicle characteristics in mind, the installation of the ETC system on motorcycles has been made possible.
ABSTRACT Embedded systems are becoming increasingly complex and more distributed. Cost and quality requirements necessitate reuse of the functional software components for multiple deployment architectures. An important step is the allocation of software components to hardware. During this process the differences between the hardware and application software architectures must be reconciled. In this paper we discuss an architecture driven approach involving model-based techniques to resolve these differences and integrate hardware and software components. The system architecture serves as the underpinning based on which distributed real-time components can be generated. Generation of various embedded system architectures using the same functional architecture is discussed. The approach leverages the following technologies – IME (Integrated Modeling Environment), the SAE AADL (Architecture Analysis and Design Language), and Ocarina. The approach is illustrated using the electronic throttle control system as a case study.
Ford's new 2.5-L inline four for 2010 boasts advanced fuel and ignition control, and an Atkinson-cycle variant for HEVs. The steady drop in U.S. retail gasoline prices does not phase Scott Makowski. As Manager of Ford's Global Large I-4 Engine programs, he knows it's only a matter of time before the fuel-price roller coaster races uphill again-sparking increased demand for his company's steadily evolving Duratec four-cylinder range. “Keep in mind the rapid shift [in the marketplace] from last spring to summer,” Makowski noted. From March through August 2008, as gas prices skyrocketed to more than $4 per gallon, Ford's North American production volumes of V8 and four-cylinder engines virtually swapped places, in terms of percent of total output. V8 production swung from 44% of the total mix to 22%, while I-4s jumped from 25% of the total to nearly 40%.
We are mass-producing the electronic throttle body (ETB). The nonlinearity of electronic throttle friction and the return spring Limp-Home affects the valve positioning performance of the electronic throttle control (ETC) system. The nonlinear computer ETB model was built based on mechanical and electrical design and experimental data. Two steps were used for the throttle valve controller design. The computer model was verified and designed by comparing the simulation results and the real throttle valve experimental data. A rapid prototyping processor was used for performance tests and validation of the controller and a low performance microprocessor was used for testing the implementation of the ETC, using the automatic production code generator.
Items per page:
50
1 – 50 of 131