Project 2
1.The p1 architechture with the electric machine connected directly to the crankshaft.the electric motor functions as a generator during vehicle decleration as engine starter and as motor during vehicle accelerations
In the mild hybrid vehicle the components on the vehicles the possible control functions and make use in terms of fuel efficiency and driveabality.by architecture topology or configuration the mechanical link between the electrical system and the rest of the vehicle is done through the electric machine ,the mhev architechture is defined by the position of the electric machine and the type of connection with the powertrain .the powertrain configuraton of the mhev system has a signifcant impact on the performance and characteristics of the vehicle in terms of integration cost,fuel efficiency,dynamic performance.
The electric machine connections points are P0,P1,P2,P3,P4.the forward modelling of vehicle this kind of approach model is known as the cause effect,engine to wheels or rear to front method.the driver controller is required to control the vehicle to follow desired speed
the controller is implemented to model that the driver will either push the accelerator or the brake pedal to match the desired speed which enables to the braking of the vehicles it also acts as the feedback loop for the vehicle which was used to determined the energy requriments to drive the vehicle.
The model of simulink is for the convection model of the vehicle in which it has been divided into three sub blocks are driver block ,controller block,powertrain block
Driver block: the driver block is the basic pi controller model is used to generate accelerator and brake pedal output that are used to match the desired and actual vehicle speeds,the pi controller controls the error between the required drive cycle and the actual vehicle speed is been provided by acceleration and brake pedal output of the controller unit.
controller: The controller block is the brain of the vehicle unit ehich represents the ECU transmission unit and basic control unit. based on the driver inputs it generates desired engine torque desired transmission gear and desired brake torque it will send feedback to the powertrain blocks as inputs which is represented the drivertrain of the vehicle.mode selection block is used to select the mode for the drive condition with four different inputs such as stop ,start,drive,and regenerative braking.the input of the blocks is accleration brake,engine speed, state of charge,soc min,soc max,idel speed and clutch lockup.the output of the blocks is mode engine on condition ,engine throttle,and electric motor torque.electric control unit is the main unit that used to run the vehicle. inputs such as engine speed maximum torque curve minimum torque idle speed control and the output is engine torque.engine idle speed: this block is used to find the idle condition of the engine.
Transmission System: this control unit has two inputs where as throttle ,vehiclespeed and gear as input,has increasing the input throttle speed changing of the gear commands take place . Gearselection: the gear command is been done by using the stateflow block for the simulation.it is controlled by vehicle speed and throttle inputs.the gear command is been passed to the transmission block to select the desired gear ratio.Brake control unit:it consists of the basic control unit which required brake pedal into the wheel block in the transmission model
Powertrain: To move vehicle it need a body structure to move the vehicles in forward and reverse direction .the components that will converts the fuel power of the engine for the motion to move the vehicle.it has engine electric motors battery system transmission wheels differential and vehicles dynamics . Engineblock: the engine speed and torque request from the controller fuel compution is taken out by using a look up table the torque from the engine spped and based on the torque engine speed is also calculated at the transmission block
Electric motor: The motor subsystem also based on the motor torque request from the controller and engine speed the torque and the input power to the motor are calculated the engine speed is conisdered because it is considered that the engine and the motor are running at the same speed in p1 hybrid vehicle . Cranksystem: in this block is used to compute the both output from the engine and e motor power into a single output to supply its transmission system
Transmission system:In the transmission subsustem is on the input crank torque and transmission speed the torque from the torque convertor is calculated based on the gear command from the controller the gear ratio is selected by considering the gear and gear ratio data from look up table product of gear ratio and torque from the torque converter gives us total output torque from the transmission based on the nature of the torque its efficency is assigned and output torque is calculated.
Differential : in the differential subsustem the transmission output torque is multiplied by the final drive ratio of the system and based on the nature of the torque negative or positive axle torque is calculated
wheels:The wheels take input from the brake torque in the control model is been subtracted from the axle torque and divideed from the rolling radius to determine the tractive force.the wheel speed is calculated from the vehicle velocity are saved in workspace.
Vechicledynamics:the block consists of the longitudinal dynamics of the vehicle which conisists of aerodynamics force rolling resistance force grade force.
Battery system: In the battery subsystem based on the input power demand from the motor the current from the battery is considered and based on the current required,the soc level of the battery is calculated by considering the technique called coulomb counting the voltage of the battery is the function of soc level of the battery so the open circuit voltage is calculated by soc level in battery.