Anti Jerk Control Of Hybrid Electric Vehicles Engineering Essay

Anti Jerk Control Of cross galvanizing Vehicles railway locomotiveering EssayThis interim report consists of three chapters explaining the initial analyze and re attend into anti click subordination of interbreeding voltaic fomites. This draw aims at electrification of anti-jerk ascendency in crossbreeding fomites by utilise the crown of thorns vehicle galvanising motor to damp these shakings and to analyze its effect on kindle consumption, alleviate and sportiness of the vehicle and then to comp ar the results with fuelling merely if method. This give will as well include studying the impact of unresisting damping with DMF in these vehicles. As a part of this be after, a sticker of a crossbred diesel motor motor locomotive locomotive exact p arntage with DMF will be developed development pretence X and an active feedback soften for an electric motor will be tendencyed to permit active damping of these oscillations.The results obtained from simulating the fix suck ups amazeed using poser X will be find oneselfd for advertizeline tremblings with respect to the frequency spue and also the range in which the goosy frequencies affect the passengers inside the vehicle so as to concentrate on it particularisedally galloping to maximum decrement in jerking of look atline.The toughies so developed will then subjected to throw modifications and investigation in accordance with the control strategies developed and affect of the very(prenominal) will be observed on all the ask devise moodls with level of jerk control chance upond. final examinationly Suggestions will be make on effect of electric motor on crossbreeding drive ensure in damping the driveline oscillations, fuel consumption and sportiness of the vehicle also analyze it with the stately drive admit models.IntroductionIn the age of railway locomotiveering science where every cardinal is concentrating on improving the products by bringing in sophisticate d technologies from cars to airplanes, we as homo beings neglected the environment particularor everyplace the years. 20th degree Celsius was called an industrial age and much technological advancement take been do in this era which revolutionized the whole world.One of the industries which is closely colligate to plug in our daily life be automobiles. Automobiles consecrate grown rapidly over the years with stiff competition among automotive manufacturers crosswise the world. As the measure passed by people become more(prenominal) demanding with their interests widening the automotive commercialize and also the fact that automotive majors started delivering those demands. These technological improvements along with human comfort factor outs all of us forgot about the effect on environment.The takings of vehicles on roads grew exp unmatchablentially and consumption figures of petrol and diesel across the world increased drastically sending out alarm bells to se bowh for alternate fuel technologies as the stuffy petrol diesel were not only running out from their existence hardly also bear on the environment leading to considerable amount of CO2 emissions and get ahead contribute to global warming. This future caper opened up opportunities for rese bowingh in alternative fuel technologies leading to the development of Hybrid vehicles, Fuel cellular ph peerless technologies Hydrogen fuelled cars. Few of the alternate fuel vehicles atomic number 18 Toyota Prius hybrid, Honda Civic hybrid, Honda perspicacity etc which have received good response in the grocery in hurt of performance as well as in trim down CO2 emissions and have success fully proved their presence in the market with their selling volumes and fuel savings.On a smaller level, these developments lead to further research in beas kindred DC/AC motors, fuel cells, bombardment pack railway locomotiveering science, advanced controller design, world causality optimization and new concepts which piece of tail be utilize as alternate fuels.Problem Definition commonly in every locomotive driven system issue of randomness, shakiness and harshness (NVH) comes along with it. Automotive manufacturers have al shipway tried to swan healthy comfort to performance ratio so as to take maximum customer satisfaction. With respect to comfort of driving, the manufacturers main aims ar to win vibration free driving pleasure as much as possible and the same applied to hybrid electric vehicles. One such(prenominal) ara of concern in drive line jerking which affects the boilersuit drivability. Jerking is a kind of driveline oscillations which occurs delinquent to excitation ca utilise by explosive or huge variation in railway locomotive tortuosity or driveline load. These excitations cause because of torsional vibration of drive train at mellowed- switched engine tortuousnesss leading to unwanted longitudinal oscillations of passenger compartment which reduces the riding comfort and drivability. These oscillations have tendency to occur at low engine zip ups which argon experienced as unpleasant jerking effect by the driver. Due to the fact diesel engines produce high crookedness at low engine speeds, makes these engines more pr unrivaled to this problem. The area of concentration under this case is vibration frequencies ranging among 2- 10 Hz as human body is thin towards this frequency range causing unpleasant driving experience.These driveline oscillations majorly occur during expiration in and intercept out conditions. In conventional diesel engine vehicles methods like active control of fuel injection into engine and passive element such as bivalent mass flywheel are utilize to permit feed forward active as well as passive damping of these unpleasant oscillations in idle, tip-in/tip out and coast conditions. To attain minimal amount of driveline oscillations, vehicle manufacturers have to compromise mingled with c omfort and performance of the vehicle. In diesel hybrids, the jerking spate be controlled by varying fuel injection and electric motor contortion control and also passively by an additional dual mass flywheel (DMF).Aims ObjectivesThe aims and objectives of this project areTo develop a model with three unalike physical bodys of reasontrain using air X those are Conventional diesel engine, Conventional diesel engine with DMF and netly hybrid billet train with DMF.To study the effectuate of jerk in each individual office train variety before developing the control strategy for anti jerk control.To telegraph the anti jerk control in hybrid vehicles by using Crank digging integrated stator/ writer to damp the oscillations.To analyze the effect on fuel consumption, comfort and sportiness of the vehicle.To compare the results with conventional fuel control method. books ReviewHybrid electrical VehiclesHybrid Electric Vehicle is the one which uses two or more sources of vital force to propel the vehicle which consists of an inhering combustion engine and electric motor fibre by batteries. Hybrid vehicles are of various types such as series hybrid, check hybrid and combination of series parallel and base on their hybridization factor they are categorise into micro, mild and full hybrids. convention 1, beneath shows the emblematic place tell type former train. Generally, hybrid advocator trains are costly to build callable to its complexness but the costs are paid off against the running costs payable to improved fuel efficiency. Regenerative braking plays an important role in conserving energy by charging the outpouring pack. normal Showing a index finger Split Hybrid PowertrainTypes of Hybrid vehicles based on drive train structureParallel HybridIn parallel hybrid vehicles, there are two parallel ways for transmitting power to the wheels of the vehicle those are by engine and by electric drive, as shown in below figure 2. The contagion is united with the motor/author and the engine, allowing either, or both, to power the wheels. Control architecture of parallel hybrid vehicles is more complex compared to a series hybrid due to the requirement of efficient coupling of the motor/ reservoir and engine so as to maintain optimum drivability and performance. mannequin Parallel Hybrid Powertrain operate modes open in parallel hybrid vehicles areEngine only tractionElectric only tractionHybrid tractionRegenerative braking series HybridIn series hybrid there is only one way for transmitting power to the wheels of the vehicle, but consists two energy sources. As shown in figure 3, the conventional engine is coupled to a generator for charging the barrage fire pack which returns electrical energy to a motor/generator to power the wheels via transmission. The motor/generator rear end also be apply for recharging the barrage fire during braking and deceleration. externalize serial publication Hybrid Power train dir ect modes for sale in series hybrid vehicles areElectric only tractionElectric traction battery charging shelling charging and no tractionRegenerative brakingSeries-Parallel (unite) Hybrid electric vehiclesA Series-Parallel (combined) hybrid vehicle has both the aspects Series and Parallel energy transfer paths. As shown in figure 5, a system consisting of motors and/or generators consisting of a adapting or power split doodad allows the engine to re agitate the battery. Changes in this power train configuration merchantman range from simple to very complex type depending on the number of motors /generators and their working terminology.These configurations can be called as Complex hybrids (such as the Toyota Prius and Ford Escape Hybrids), Split-Parallel hybrids, or Power-Split hybrids.Figure Series-Parallel (Combined) Hybrid Power trainDriveline JerkingDriveline jerking also called as driveline oscillations can occur due to many different factors such as load changes, gear displacement and also the condition of the road. In recent times, direct injection diesel engines with extensive refinement of components and significant weight reduction in driveline lead to the problem of driveline jerking. Also with advancement in diesel engine technology over the years, issue torque of these diesel engines has risen tremendously for passenger cars effecting the comfort and drivability. The problem with high engine torque is, it causes torsion of driveline due to the gear ratios of the final drive causing the torsion at drive shafts which in turn causes whole power train to oscillate with combined effect of vehicle jerking. Figure 5, shown below show the measurements on a test car ca utilise by tip in behavior in which driver suddenly steps on the throttle combined with high torque gradient and tip out condition, the back out maneuver.Figure Engine torque and engine speed for tip in and tip out maneuvers.though the oscillations caused by engine speed are sligh tly absorbed by engine mounts but the oscillations due to wheel speed is responsible for horizontal vibrations of the vehicles longitudinal acceleration affecting the performance of the vehicle which is experienced directly by passengers. To restrain these oscillations affecting the comfort and drivabilityfor the passengers, damping of these driveline oscillations is infallible which is referred to as Anti Jerk Control. The oscillations leading to power train jerking in conventional power train can be categorized by the Eigen frequencies of following driveline componentsTorsion of shafts causes pitching and jerking due to good luck system, mass of the vehicle and damping. The range of frequency for this cause lies between 2 5 Hz. Also, we know that the natural frequency of the vehicle with respect to pitch motion is lies between 1 2.5 Hz.The frequency of oscillations caused by engine driving force and mounts lies in the range of 15 200 Hz.The vibration due to gearbox assembly lies in the frequency range of 50-80 Hz.There are oscillation depending upon the type of engine, no. of cylinders, engine speed and also the combustion execute shown in below figureTable showcasing different engine types and their Eigen frequenciesEngine TypeMultiples of Eigen Frequency4-Cylinder ,R4, 4-Stroke2,4,6,8,106-Cylinder,R4, 4-stroke3,6,96-Cylinder,V60,4-Stroke1,5, 3, 4,5, 6, 7,5, 96-Cylinder,V90,4-Stroke1,5, 3, 4,5, 7,5, 912-Cylinder, V60, 4-Stroke6,12From the above categorization of the components and their individual Eigen frequencies, the main aim is to narrow down on the components leading to vibrations which are felt by passengers majorly and to minimize the level of vibrations by designing model based predictive control strategy age retaining the performance of the vehicle as much as possible.Hybrid Vehicle DesignThe power train which has been considered for testing the jerking behavior and the anti jerk control strategy to be designed is shown in the below figu re 6. This power train is one of the possible hybrid vehicle architecture consisting of I.C engine, CISG (Crankshaft merged Starter/ Generator), Dual grass Flywheel (DMF), suitcase, caravanbox assembly , High potentiality battery pack and power electronics.Figure Hybrid Vehicle architectureIn operation, at lower rpm the vehicle acts as excellent electric vehicle powered by the on dining table battery pack and at higher rpm, both electric drive and I.C engine together produce required power by the vehicle. The percentage of power transmission sharing to propel the vehicle plays an important role in determining fuel efficiency.Design ConsiderationsThe components and factors which play important role in hybrid electric vehicle design shown in figure 6 areEngine design and selection The I.C engine as in conventional power train plays an important role in hybrid vehicles. Generally, engines designed for hybrid vehicles are smaller in size compared to conventional vehicles. Thoug h the design selection of the engine is completely based on the power requirements of the vehicle.Crankshaft integrated starter/generator (CISG) The starter/generator is device which is controlled electronically. It combines both the functions of a conventional starter and generator into a one single unit. The motive of single CISG unit is replacing the starter as a single entity which is passive in nature need to switch over the old fashioned belt and pulley type connection between the alternator the engine. Also to replace the modern day rotor wound alternators with compositors case rings and brushes. The integrated starter/generator works as a bi-directional device which converts electrical energy to mechanical work and vice versa. As a electric motor, it assists in starting the I.C engine without any noise and also much suppleer than conventional starter. As a generator it produces power required for electrical components of the vehicle and is also used to charge the batt eries. Commonly integrated starter/generator is placed between engine and gearbox assembly. The main operating features of ISG are it enables stat/stop, onboard power generation and acts as power assist when required.Figure Integrated Starter / Generator.Dual Mass Flywheel (DMF) Dual mass flywheel consists of two flywheels machine-accessible by long arc travel springs located between I.C engine and delay or transmission. The beginning DMF was introduced for the automotive industry in 1985. At that time non lubricated dampers were used consisting of heavy springs which were problematic. consequently there was breakthrough in the DMF technology and arc spring type dampers was introduced in 1989 solving almost all the problems which were caused by DMF earlier. Due to the high cost of this product not everyone was interested but was used in large vehicles. Though DMF is a passive driveline element, it has been prove that DMF reduces torsional vibrations to certain extent and plays an important role in anti jerk control of hybrid vehicles also. The operating performance of DMF can be characterized by the spring rate and its damping characteristics.The dual mass flywheel consists of following important characteristics unproblematic and substitute(prenominal) inertias.The torsion damper rate.And the damping characteristic.Advantages of using DMF in conventional power train areSegregation of torsional vibrations we know that, torsional vibrations are caused by torque fluctuations. A vehicle is a kind of vibrating system with all the components like engine, transmission, drive shafts etc all contributing to the cause. Below figure 8, shows the simple driveline model so as to observe vibration behaviour. In this case engine and transmission are supposed as rotating inertia connected by springs. The spring C2 represents the spring damper characteristics and spring C3 showing the stiffness of the drive train.Figure Drive train with vibration modes.Figure 9 shown be low depicts the fluctuations in vehicle speed and in this case damped resonance occurs at around 1700 rpm. The main aim of DMF is to sideline the vibrations occurring from the engine as distant as possible from the rest of the driveline components. Also the figure compares the difference between the extents of vibrations in a conventional drive train compared to one fitted with dual mass flywheel. Dual mass flywheel efficiently reduces the engine vibrations and reduces gear rattle, helps in saving the fuel consumption and also improves driving comfort.Figure comparing of vibration damping in a conventional drive train to the one with DMFTransmission assistance As DMF is said to reduce the engine vibrations, it has confirming effect on the transmission system as the stress generate will be significantly less compared to a compared drive line increasing the transmission efficiency and cycle life.Crank shaft assistance In a conventional power train, we know that flywheel and clut ch are connected to engine crankshaft rigidly and due to the inertia of the flywheel high chemical reaction forces are developed on the crankshaft. But in case of DMF, the secondary flywheel can be neglected for bending load case as it connected loosely to the pristine flywheel by torsional damper and roller bearings which practically dont allow high transferable reactive forces. The primary flywheel is significantly brightness in weight, more elastic in nature compared to conventional flywheel.Battery pack design and selection The main criteria in battery design and selection depend upon the capacity, the output characteristics based on type of battery pack to be used, cycle life, cost, scope of reusability and whether recyclable on not. The size and weight of the battery pack depends on the capacity requirement. If capacity is high, more will be size and weight of the battery pack. In fact, battery pack design plays a very important role as the performance of the vehicle is dep endent on the overall weight of the vehicle. In case battery pack is heavier, this would have direct impact on the power catchd to propel the vehicle which is develop to rise with increase in battery weight and will also reduce the operating range of the vehicle.Figure Typical Battery pack arrangementElectric force Generally AC, DC and PMDC electric motors are used in hybrid vehicle depending upon the requirement and usage. In automotive industry, certain motor specifications are not acceptable due to their inability to meet the specific requirements such as power rating at peak load conditions, unvarying power supply, volumetric power density, cost, efficiency, weight, lifetime, level of protection against water and dust.Gear box assembly In hybrid vehicles, mostly a power splitter device is used which is consists of artificial satelliteary gear set allowing power flow from two power generating sources to propel the vehicle. The I.C engine is generally connected to Sun gear w hile electric motor is connected to the planet gear.Clutch It is found in every vehicle with manual of arms gearbox. Though the use of clutch varies from one hybrid drive train to another(prenominal) depending the gearbox being used as most of the hybrid power trains use automatic transmission which dont require clutch. The main purpose of clutch is to assist the vehicle starting off from stand still go under as it compensates for the speed difference between engine and the driveline and slips on to synchronize both. Clutch also used to engage and disengages engine from the transmission while gear shifting takes place.Modelling ApproachProcedure of workPower train jerking in hybrid vehicles is majorly due to engine electric motor torque changes during tip in and tips out operations. For investigating the problem of jerking for a hybrid vehicle, certain steps have been lay out for mildew the power train in five different steps which are in below figure 9 to observe and analyze e ach case individually with root causeFigure Modelling ProcedureBasic Driveline EquationsEngine The engine output torque is expressed by the driving torque (Te) generated from combustion , friction torque (Tfric,e) and the external load from clutch (Tc) .By Newtons second law of motion, we can achieve the following modelWhere Je is the mass of inertia of the engine, is the crank angular acceleration.Clutch Generally a friction type clutch is installed in vehicles with manual transmission connecting to the engine flywheel and input shaft of the transmission. During clutch engagement if we come in no inherent friction, Tc = Tt can be obtained. Then the torque transmitted is function of angular difference (cs c) and angular speed difference ( ) resulting inFigure vehicle driveline with corresponding move and torque labels.Transmission A transmission consists of a gear set each with a different operating ratio it leading to sexual congress between input and output torqueWhere Tp is the transmission output and Tfric is the internal friction torque of the transmission.Propeller shaft The shaft which connects the transmissions output to the final drive unit in which no friction is assumed which gives us Tp = Tf , resulting in model for torque input to final driveFinal Drive final drive can be considered as a final ratio if as for the transmission leading to input and output torque relationDrive Shafts The shafts which connect wheels to the final drive are called drive shafts. It can be assumed that both the wheels are rotating at same speed ( ). Ignoring the vehicle dynamics, the wheel speed shall be suitable to speed of vehicle bodys centre of gravity.Therefore, drive shafts can be modelled as one shaft.Wheels The forces acting on a vehicle with mass (m) and fastness (v) the longitudinal forces (FL)acting on the vehicle givesRolling resistance (Rr) = f*m*g and Aerodynamic drag (Ra) =1/2*Af*Cd**V2.Where, m=mass of the vehicle, g=gravity constant, f=0.015(co -efficient of rolling resistance), Rr=rolling resistance, Ra=aerodynamic drag, Af=cross sectional area, Cd=coefficient of drag, density (), V=velocity.The drive line model can be expressed as a system consisting of rotating lumped inertias, compliances, damping tone endinges, input torque and loads acting due to environmental resistive forces. A simple 2 degree of freedom model (fig 10) is sufficient to show the first torsional mode of vibrations which lead to jerking of vehicle.Figure Free body diagram of a conventional drivelineWhere, Teng = engine torque, road load = Tload , e = engine speed, v = vehicle speed, Je = mass issue of inertia, be = viscous friction, r = final drive ratio, Ks CS = drive shafts flexibility, Cw = damper, vehicle inertia = Jv.Hybrid Power train ModelAs discussed earlier in report, the hybrid power train consists of additional components compared to conventional type which include electric motor, batteries, power electronics which form together the el ectric drive unit of the vehicle.Engine Engine in hybrid power train plays a very important role in terms of fuel savings and vehicle assist. An engine model to be used for hybrid power train must be considered for following issuesThe engine model must produce desired torque output disregardless of operating conditions.The engines dynamic behaviour leading to torque fluctuations generates drive line vibrations which in turn affects the driver comfort.As engine is not quick enough to respond to control actions implemented externally, the response delay can have significant affect on the vehicles performance.Engine can be modeled in many different ways depending upon the level of complexity required and the availability of parameters which can later be used for validating the inputs. The introductory equation of engine model has been already discussed earlier which can be applied for the hybrid power train model also.Electric Motor/ Controller The electric traction motor and contr oller consume the power from the onboard energy storage device like battery to provide the power source so as to generate the required torque for vehicle propulsion. The electric motor can also be used as starter/alternator or as a generator to regenerate energy during braking which can be used to charge batteries. The traction motor model can be described by following equationsWhere idr , iqr are d,q axis vertebra rotor online respectively ids ,iqs are d, q axis primary current respectively Lm, is mutual inductance Lr , LJ are resolved rotor, stator inductance respectively P are poles Rr, Rs are resolved rotor, stator resistance respectively, ohms Vds Vqs are d, q axis primary potential respectively, V dr and qr are d, q axis rotor equivalent flux respectively, V-sec ds and qs are d,q axis stator equivalent flux respectively, V-sec e is synchronous frequency, rps r is rotor frequency, rps , is rotor acceleration, rps2 Ts is electric motor torque, Nm.The limiting torque of the m otor can be expressed byWhere b, is motor base speed, rpm m is mechanical motor speed, rpm Prated is the rater motor power, hp Trated is the rated motor torque, Nm Tm is mechanical motor torque, Nm.In addition to this, equations of motion for DC electric machine areWhere is the torque output of the machine relative to the armature current, e is the back emf of the machine is proportional to the velocity of the rotorDrive Shaft The drive shaft plays very important role in the drive train for transmitting the torque and rotation. They are subjected high torsion and shear stresses and therefore must have must have high stiffness. Below shown in the drive modelled using lumped inertias and their corresponding grassroots equationsTDS =KDS (T W) + CDS (T W)Wheels The forces acting on a vehicle with mass (m) and velocity (v) the longitudinal forces (Fe)acting on the vehicle givesStationary model of the vehicle assumptive all forces act through the centre of gravity and only in longitu dinal direction.Gears Assuming no losses in transmission the basic equation for gearing isBut in reality there are viscous losses, sealing bearings drag contact friction. Losses vary with gear change but can be modelled as a loss torque tl acting on the transmission input shaft there can be shown asCapacitor It is device which stores energy an can be modelled by current equationBattery Batteries are characterized by energy density, C-rating, cycle life, thermal run away and variations in temperature. Table below shows the comparison among different types of batteries with their technical specifications available in the market for HEV applicationsPropertyLead AcidNiMHLithiumCell electromotive force Volts21.23.6Energy Density WH/Kg30-4050-80100-200Power Density W/Kg100-200100-500500-8000Maximum Discharge Rate6 -10C15C100CUseful mental ability DOD%5050-8080Charge Efficiency %60-8070-90100 ego Discharge %/Month3-4302-10Temperature Range C-40 +60-30 +60-40 +60Cycle Life Cycles600-90010 002000Micro-cycle TolerantDeterioratesYesYesRobust ( over/Under Voltage)YesYes ask BMSCost per kWH100170150 TargetA basic battery model might include an open circuit voltage and internal resistance Rc and RdSOC CalculationSOCic = initial SOC of the battery (assume 1 fully charged)Ibat = battery current that can be both positive and disconfirmingQbat = battery capacity (Ah), needs converting to A.s for the simulationSimulation ToolSimulation XSimulation X is a multi domain program for modeling and simulation created by ITI GmbH. Some of its main features and capabilities areEnables high level modelling platform for complex systems.Integrated with CAE design toolOver 30 standard industry specific libraries including automotive.Development of user specific libraries based on standard ones.Object oriented modelling manner of speaking for simple and efficient modelling.Implementation of user based C label through external sources.Provides interface between various software available i n market such as MATLAB/Simulink etc.Analysis tools available in Simulation X areTransient Simulation suitable of computing linear and non-linear models in the time domain.Steady State Simulation Analyzing the models in periodic steady state condition dependent on a specific reference value.Linear System Analysis (Natural frequencies and mode shapes) Efficiently generates damped and un damped natural frequencies of the complete system , time constants , eigen vectors, oscillations of state variables related to particular eigen frequencies.Linear System Analysis (Input Output Analysis) Enables linearization in the current operating point , analysis, export of state space matricesModelling in Simulation XThe vehicle type selected for the analysis of jerking and its do is a sport utility vehicle (SUV) powered by a diesel engine shown earlier in figure 6 consisting a conventional diesel engine with crankshaft integrated starter generator (CISG), a DMF, a transmission gear box, a clu tch between the transmission and the DMF, differential as a part of conventional power train and high voltage battery pack with power electronics on board as electric drive unit for the vehicle. Creating simulation models for hybrid power train requires various components of power train such as mechanics, hydraulics, electronics and pneumatics including the control aspects involved.