Development Of Diesel Injection-cylinder Pressure Feedback Closed Loop Control System With DSPACE

Research and Development of Diesel Injection-cylinder Pressure FeedbackClosed Loop Control System with dSPACE is mainly composed of analytical unitiCAT combustion in cylinder, dSPACE rapid prototyping and CA6DL2-35E3turbocharged inter-cooled diesel engine of three main parts.Its principle isthe use of cylinder pressure sensor and speed sensor acquisition and thecylinder pressure signal, crank Angle signal, and then the combustion incylinder analytical unit iCAT by combustion in cylinder and the cylinderpressure signal, a cycle collection on crank Angle signal in real time tocalculate the parameters of the combustion in cylinder CA50, IMEP, CA50andIMEP as feedback variables by dSPACE rapid prototyping to calculate thecombustion in cylinder in the next cycle of injection advance Angle and cyclefuel injection quantity, and the control of diesel engine fuel injection ascontrol variables.The development of the whole Research and Development of DieselInjection-cylinder Pressure Feedback Closed Loop Control System can be dividedinto two parts: the software part and hardware part.Software part mainlydevelop dSPACE closed loop controller as the cylinder pressure feedbackclosed-loop control system of software systems.Hardware part includescylinder making dSPACE rapid prototyping, analytical unit iCAT combustion incylinder, dSPACE hardware connection between rapid prototyping and CA6DLdiesel engine and signal processing.This research mainly with the method of off-line simulation developmentvalidation cylinder injection pressure feedback closed loop control system of software system, first of all, according to the CA6DL3-35e3diesel engineparameters and bench test steady-state data use GT-the POWER to establishthe accurate CA6DL2-35e3virtual diesel engine model, GT-POWER modelingcan be divided into diesel engine inlet and exhaust system, exhaust gasturbocharger, cylinder and the nozzle four modules.Inlet and exhaust systemmodeling is based on diesel engine into the exhaust pipe shape modeling,exhaust gas turbocharger modeling is according to the turbine and compressorcharacteristic curve, the cylinder model according to the characteristics ofthe diesel engine combustion pressure to select suitable combustion model,nozzle modeling is selecting suitable nozzle model according to the controlvariables.Modeling is completed, this study based on the steady workingcondition of54points of simulation verify the accuracy of the model.This study with Matlab/Simulink software system development of the nextstep is to set the diesel engine fuel injection closed loop control model,mainly divided into speed torque control, CA50as feedback variables of fuelinjection advance Angle control and the IMEP as feedback variables cycle fuelinjection quantity of three PID closed-loop control.CA50is the cumulativeheat release rate of50%of the crank shaft Angle.Closed-loop control modeldesign is the process in accordance with the bench test, after the engine start,with constant speed torque of PID control diesel engine speed stability attarget speed.Then when the accelerator pedal, working condition of dieselengine by the steady-state condition to a transient conditions, start by CA50and IMEP PID control to control the fuel injection.Control strategy based onsteady state100cycle CA50and IMEP as target value, the average of eachcontrol fuel injection advance Angle and cycle fuel injectionquantity.Closed-loop control model to build, joint simulation withMatlab/Simulink and GT-POWER in the form of offline simulation, respectively,under the1650r/min speed of5s to8s inside the throttle opening from10%-100%under the working condition and1650r/min speed,5s-within15s working condition of throttle opening from10%-90%control effect forvalidation.By combined the results of simulation and transient bench test data,the steady-state target comparison, found in3s accelerated conditions, CA50transient test value than the steady state data after3°CA, and jointsimulation control data than the steady state data back only1°CA, IMEPdata for the straight line, the transient test data and steady state test datashow slight Angle intersection, and almost overlap joint simulation controldata and static data.In10s accelerated conditions, CA50transient test valuethan the steady state data back1°CA, and joint simulation control datathan the steady state data back only0.5°CA, IMEP data remains as a straightline, the transient and steady state data show slight Angle intersection, andalmost overlap joint simulation control data and static data.To sum up, theMatlab/Simulink to build fuel injection control closed loop controller isbetter than the transient test.Based on dSPACE injection diesel enginecylinder pressure feedback closed-loop control system software partcompleted.Injection diesel engine cylinder pressure based on dSPACE feedback closedloop control system hardware system of the combustion in cylinder analyticalunit iCAT made from tianjin university, compared with the bench test ofcombustion analyzer advantage to real-time calculation of iCAT CA50, IMEP,maximum cylinder pressure and the pressure rise rate of cylinder combustionparameters, guarantees the closed-loop feedback control variables real-timecalculation.DSPACE rapid prototyping manufacture is mainly for the treatmentof closed loop control system hardware connection interface and download thesoftware system to dSPACE hardware.Hardware in loop test is used to implementthis study of the oil cylinder pressure feedback closed-loop control systemhardware connection and the realization of signal processing.At present, thisstudy has achieved on diesel engine air intake pressure sensor and theaccelerator pedal sensor hardware in loop test.Connect the air intake pressure sensor and the accelerator pedal sensor dSPACE system, through the sensorsoftware ControlDesk observation of dSPACE intake pressure sensor and theaccelerator pedal sensor in the pressure change and the pedal position changeof the change of output value, success with air intake pressure sensor tomeasure the atmospheric pressure.ControlDesk transformation characteristicsof the observed value of change and the sensor and the output characteristiccurve is consistent.Hardware in loop test results are accurate.This study of diesel engine cylinder injection pressure feedbackclosed-loop control system of software system is completed, the hardwaresystem of other hardware interface connection and signal processing to becompleted the next step.