Project
Aim:-
- To study and observe the content of main elements of ATV model with continuously variable transmission CVT in open loop condition and in close loop condition using lookup table
MAIN ELEMENTS:
- Signal builder
- Solver configuration
- Engine
- To and from
- Simple gear
- RPM sensor
- PS-simulink converter
- PS terminator
- Input shaft inertia
- Variable ratio gear
- Double shoe brake
- Vehicle body
- Tire
EXPLANATION & OBSERVATIONS:
- ENGINE:-
- It is a machine that uses the energy from liquid fuel or steam to produce the movement of the object Heat engines are transform the heat into the movement through various thermodynamic process.
- Commonly used heat engines are internal combustion engine in the engine ie internal combustion chamber the fuel is injected in the chamber, ignition is on and the combustion is done cousing the expand and drive the piston which produce the mechanical energy to the shaft.Emissions which are produce due to the combustion are released through th valves of the engine.
- CONTINOUSLY VARIABLE TRANSMISSION:-
- CVT is a automatic transmission that can change coherrently through a continuous range of gear ratios. This contrasts with other transmissions that provide a limited number of gear ratios in fixed steps.
- The flexibility of a CVT with suitable control may allow the engine to operate at a constant RPM while the vehicle moves at varying speeds.
- Its Used in vehicles, tractors, motor scooters, snow automobiles, and earthmoving elements.
- The most common type of CVT uses two pulleys connected by a belt or chain, however, several other designs have also been used at times
- Simple gearbox:
- A gearbox is a transmission device,used between engines output shaft and the final drive shaft between engines output shaft and the final drive shaft seamlessly to transfer required torque and power to the wheels of automobile, gear contains of the group of gear(I.e. spur, helical, bevel, worm, epicycle depending on the types of gear box used) which are arranged in a special fashion to provide specified gear or speed ratio to the final drive of the vehicle, a gear box usually comes with the special specification I.e. 5 speed transmission with a reverse, and an automatic transmission.
- Vehicle body:-
- It is the main supporting structure of vehicle or automobile to which all other components are attached. tuck use a separate frame at chassis
#cvtModel
- Here in this model break and throtal are inputs the break signal is constant and the total is suddenly change at 20sec in signal builder.
- This input signals are connected to the input throttle signal point 'T'. to observe the further responses of the vehicle parameters.
- second signal builder CVT gear ratio signal is designed and connected to the primary pully of CVT
- CVT subsystem:-
- Input shaft inertia, variable ratio gear and ideal rotational sensor are connected as shown in the fig. outputs can observe in sensors.
- Engine subsystem:-
- Engine is connected to the RPM sensor, angular velocity 'W' port of the RPM is connected to the scope
- In the simple gear change the gear ratio to 10. further connected to the vehicle body
- Vehicle body subsystem:
- In this sub model vehicle bodies connected to 4 Tyres and dual shoe break velocity, throttle and brake are connected to the one scope and CVT primary and secondary shafts outputs are connected to another scope. Using To and from block connected.
- Engine torque speed curve:-
- Car data points are fit to the engine by using GABIT. GABIT is a file exchange file which can grab the data from any picture or graphical representation.
- Graph:-
- The velocity is rapidly change between 20 to 40 seconds and further gradual increasing throttle and break are shown in the graph signal of throttle is changed 0.3 to 1 and break signal is constant.
- In this CVT primary Pulley moves inside and secondary Pulley moves outside so radius of primary shaft is greater than the secondary shap does angular velocity of the secondary observe in output graph.
- As a result secondary shaft is connected to the wheels sharp both velocity of vehicle and secondary angular velocity graph are same.
#cvtModel
- To the same model add few dashboard elements such as knob circular gauge to change inputs while through running the simulation.
- in the above model knobs are connected to the break and throttle input circular gauge are connected to the engine RPM and velocity of the vehicle
Conditions:-
- Initial conditions to run the model are brake as 0 and throttle as 0.5.
Blocks:-
- Signal Builder:-
- There signal builders used is to input to provide cvt ratio.
- Generic Engine:-
- It is simscape block which acts as typical internal combustion engine and produces rotational movement and output in terms of force
- RPM Sensor -
- It is not simscape block it is user defined subsystem to to sense the force from the engine and give output in terms of angular moment.
- Cvt Subsystem:-
- Cvt system is not simscape block which is subsystem created with the help of simulink blocks, it takes the rpm and Cvt ration as input and give the two output one when the Cvt ration is not applied and the other one is when ratio is applied that is basically output shaft. Simple Gear Simscape block acting as the gear.
- Vehicle body:-
- It is consists of several vehicle simscape parts connected to each other which takes gear power and break as input and get vehicle speed and distance as output.
- Scope:-
- It is typical simulink block to plot the graphs against time.
Observation of model:-
- It initially we change the brake value to some other than zero and keep throttle constant then the initial speed is little lesser than the 60
- If we go according to the initial condition and run the model simulation it will show contant initial speed
- Again if we lower throttle value and increase break value speed will lower again if increase throttle with same break the speed increased upto 60
- There is some error with model as we increase the break value an reduce the throttle it will go down to slower speed and eventually to zero but again if we increase the throttle and lower the breaking value to zero speed will not increase and remain to zero
Graphs:-
- Primary RPM is the input rpm in CVT and Secondary is Output
- Graphs shows shows the velocity distance and brake throttle values.
#The two models are open loop model of a TV models and now we will observe and study about the closed loop models of the ATV model using look up table lookup table connected between the velocity of the vehicle and primary shaft or Pulley of CBT in reality close loop or feedback model ATV models are used:
#cvtModel_cvtratio_rpm
Graphs:-
- Resultant velocity, distance, throttle, brake shown in graph.
- primary and secodary shaft rotation graph show in graph.
- The graphs shows the approximately correct values according to input.
#cvtModel_mapped
- Graph:-
- In the look up table visualisation graph is plotted between velocity of x-axis and CBT ratio on y x
- Angular velocities is of the primary and secondary shafts of CVT and velocity output graphs of the close loop are shown
- Results and Conclusion:-
- The CVT simulink model has been studied well.
- Hence the study and conduct of the ATV model in open and close loop are completed successively.
- The graphs shows the approximately correct values according to input