Project
Aim :
To prepare a technical report of simulation of BAJAJ All Terrain vehicle (ATV) Using Different Conditions.
Tasks :
Carry out a system-level simulation of an all-terrain vehicle & Prepare a technical report explaining the model properties & comments on the results.
Theory To Remember :
All Terrain vehicle :
An all-terrain vehicle (ATV) is defined as a motorized off-highway vehicle designed to travel on four low-pressure or non-pneumatic tires, having a seat designed to be straddled by the operator and handlebars for steering control.As Shown in Figure
An all-terrain vehicle (ATV), also known as a light utility vehicle (LUV),[1] a quad bike, or simply a quad, as defined by the American National Standards Institute (ANSI); is a vehicle that travels on low-pressure tires, with a seat that is straddled by the operator, along with handlebars for steering control. As the name implies, it is designed to handle a wider variety of terrain than most other vehicles. Although it is a street-legal vehicle in some countries, it is not street-legal within most states, territories and provinces of Australia, the United States or Canada.
By the current ANSI definition, ATVs are intended for use by a single operator, although some companies have developed ATVs intended for use by the operator and one passenger. These ATVs are referred to as tandem ATVs.[2]
The rider sits on and operates these vehicles like a motorcycle, but the extra wheels give more stability at slower speeds. Although most are equipped with three or four wheels, six-wheel models exists and existed historically[3] for specialized applications. Multiple-user analogues with side-by-side seating are called utility terrain vehicles (UTVs) or side-by-sides to distinguish the classes of vehicle. Both classes tend to have similar powertrain parts. Engine sizes of ATVs currently for sale in the United States (as of 2008 products) range from 49 to 1,000 cc (3.0 to 61 cu in).
Task 1 :
Case 1 :
Simulink Model For BAJA ATV With CVT :
Main Components :
Continuously Variable transmission drive (CVT) :
A continuously variable transmission (CVT) is an automatic transmission that can change seamlessly 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.
CVTs are used in automobiles, tractors, motor scooters, snowmobiles, bicycles and earthmoving equipment.
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.
It does not use gears like a typical transmission. Rather, it uses two pulleys connected by a belt. It's a little bit like a snowmobile transmission: One pulley connects to the engine, the other pulley attaches to the transmission. The belt transfers the power in between them.
CVT Block :
Variable Transmisson Ratio :
The Variable Ratio Transmission block represents a gearbox that dynamically transfers motion and torque between the two connected driveshaft axes, the base and the follower.
Represents a variable ratio gearbox such as implemented by mechanical belt CVT, electric, or hydraulic transmissions. The physical signal input r defines the ratio of input to output angular shaft velocities.
Connections B (base) and F (follower) are mechanical rotational conserving ports. Specify the relation between base and follower rotation directions with the Output shaft rotates parameter
Generic Engine :
Represents a system-level model of spark-ignition and diesel engines suitable for use at initial stages of modeling when only the basic parameters are available. Optional idle speed and red line controllers are included.
The throttle input signal T lies between zero and one and specifies the torque demanded from the engine as a fraction of the maximum possible torque. If the engine speed falls below the Stall speed, the engine torque is blended to zero. If the engine speed exceeds the Maximum speed, the simulation stops and issues an error message.
Connections F and B are mechanical rotational conserving ports associated with the engine crankshaft and engine block, respectively. Connections P and FC are physical signal output ports through which engine power and fuel consumption rate are reported.
Input Signal :
A Signal builder is used to create signals for brake & throttle.
CVT Gear Ratio Input :
Torque Vs engine speed output :
Vehicle Body :
Output For Case 1 :
Vehicle Speed :
it is clear from the graph that the vehicle attains its maximum speed (V = 65km/hr) at full throttle = 1 after 30 seconds and then remains constant. The brake input value is zero, hence no effect on velocity.
CVT Shaft Rpm :
The graph shows variation in angular velocities of input and output shafts of the variable gear transmission system. These Values differ with respect to the gear ratio.
Case 2 :
Simulink Model For BAJA with ATV using dashboard :
In this model we have a dashboard which contains knobs to control thr inputs. In the case, the inputs-'Throttle' & 'Brake' are not provided using signal builder. A knob is provided to control both the parameters in real time for the user.
Output for Case 2 :
Vehicle Speed :
It Can be observed from the graph that the velocity of the vehicle increases drastically from 0 to 50kmph when throttle value is 0.5 & brake input is 0. Once the braking value increses from 0.1 to 0.5, the velocity of the vehicle decreases to 0 at constant throttle value. This Explains thr direct relation of velocity with respect to throttle and brake inputs.
CVT Shaft Rpm :
Task 2 : [Using Lookup Tables]
Case 1 :
Simulink Model For BAJA ATV With CVT Using Lookup Table :
CVT Block :
The only difference between this Model and the First model is that in this model, the gear ratio input to CVT is provided using a lookup table. The vehicle velocity and shaft rpm outputs are same as before.
CVT Gear Ratio :
Look Table Visualisation :
Output :
Vehicle Speed :
CVT Shaft RPM :
Both Results are same as that of first case,Since The input Parameters are Same .
Task 2 :
Case 2 :
Simulink Model For BAJA ATV With CVT Using Lookup Table & Dashboard :
In This Model of a dashboard is used to control the inputs-'Throttle' & 'brake' with knobs.
Output :
Case 2 :
Vehicle Speed :
This Graph is similar to that of cvt dashboard case. The Variation in Vehicle can be observed with change in throttle and brake inputs. With increase in braking value, the speed of vehicle decreases. On the other Hand,increasing the throttle leads to increased vehicle velocity.
CVT Shaft RPM :
This indicates the variation in RPM of primary & secondary shafts with respect to input parameters .
Conclusion :
Thus We Have Sucessfully intialises and tested of 4 different models of BAJA ATV with CTV and Submitted the outputs,Likely Vehicle velocity, CVT Shaft RPM, Signal builder, Engine Torque & Visualisation Of Look Table Curves & Graphs.