Project
SYSTEM LEVEL SIMULATION OF ALL-TERRAIN VEHICLE
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There are five different level are considered for the terrain vehicle. Each working with specific differenciations.
- All terrain vehicle model has same CVT sub system and vehicle body, In some modelas only the provide a 1-Dimensional look-up table for the input to the CVT.
3. The difference is due to dfference in input supply and some having Closed Loop or Feedback Configuration, Which automatically adjusts its CVT ratio.
4. Five different methodologies are observing seperately using output and the input.
1. CVT RATIO INPUT USING SIGNAL BUILDER BLOCK
1. It is the first simscape model and it is a open loop model, here input is used as brake & throttle which is given using signal builder block.
2. Here CVT ratio is given using a signal builder block to the variable ratio gear.
3. The throttle input is given to the Generic Engine in which 'T' (input) is normalised engine throttle level, 'P & FC' are output as power & fuel consumption, 'B' is a conversing port used to connect Solver
Configuration, 'F' is also a conversing port is connected to a sub system, then given to a subsystem CVT.
4. In CVT, it consist of Input Shaft Inertia, Variable Ratio Gear, Output Shaft Inertia, Rotational Motion Sensor.
5. These are connected in accordance so that it is given to the vehicle body using a Simple Gear System.
6. The vehicle body consisit of Inertia shaft, Double shoe brake, Left rear, Left front, Right rear, Right front which gives an output as velocity and distance.
7. Here we apply a throttle of "0.5" and brake of "0".
8. The output observed as the distance is keep on increasing linearly & the velocity is increasing exponantially and stay constant through out the time.
2. CVT RATIO INPUT USING 1-DIMENSIONAL LOOK-UP TABLE OF RPM
1. On this CVT model, CVT ratio is given using 1-Dimensional look-up table of RPM. It is also a openloop system with the same output of the initial simscape model where CVT ratio is given using signal builder.
2. The input to the CVT sub system is given using Look-Up table of Engine Sensor sub system.
3. In this Brke input is given as "0" and Throttle input as "1" through out the process.
4. The result is same as that of the 1st system, as Distance increasing linearly and velocity increasing exponantially through out the system.
3. CVT MODEL USING DASHBOARD AND MAPPING
1. Here Throttle input and Brake input is given using Dashboard System.
2. We can manually change the Throttle input and Brake input as needed by touching the knob position.
3. It is simple and efficient method to look after each value input to the output by easily changing Throttle input value and Brake input value.
4. It is a closed loop system, because the output velocity is mapped (feedback) to the CVT subsystem.
5. Depend on the output (velocity) the system automatically changes its function.
6. The gear change is done by calculating the velocity and it is done automatically by using feedback methodology.
7. Initial condition to run this simulation is as Brake=0 , Throttle =0.3
8. Here Look-Up table provided inside the CVT subsystem.
9. All other parameters are same as that of the initial simscape model. The output are being verified using Scope.
4. CVT MODEL USING DATA
1. It is similar to that of the "CVT model using RPM and Look-Up table" simscape model.
2. The input to the CVT subsystem is given using a signal builder block as CVT ratio. This ratio is normally given to the 'r' port of Variable Ratio Gear block.
3. The 'r' port gives the ratio of input to the output shaft velocity.
4. All others are same as that of mention in the earlier segments.
5. Here Brake input is kept '0' in all time interval & Throttle input as '0.3' for time of 20 seconds and 1 for rest of the time.
6. The output velocity is obtained for a time of 20 seconds it is slowly increasing, for a time of 20 to 40 seconds it is rapidly accelerating then after 40 seconds gradually increasing value upto 60 km/h.
5.CVT MODEL-MAPPED
1. It is a closed loop system, in which velocity is feeding back to the subsystem CVT.
2. In CVT, there is a Look-Up table provided which is given to the "Variable Ratio Gear" block in 'r' port.
3. Because it is a closed loop system, the gear value is automatically changed depending on the output velocity value.
4. Here the Brake input & Throotle input is given using "step signal" block.
5. Brake input is kept "0" all the time for a step of 35.
6. Throttle input is kept initially "0.3" and finally for "1" for a step of 20.
7. The output graph is obtained similar to that "CVT MODEL USING DASHBOARD & MAPPING", the velocity is keep on increasing as the time increases.
* Each model has its own differences and the output value is depend on the input and the feedback of the system.
* A simscape model of a system can be done using various ways. For me, "CVT MODEL USING DASHBOARD AND MAPPING" seems more efficient and easy to understand.