Challenge

Week - 4

JJanakiraman Rajendran18 Oct 2021

1. AIM

To implement control logic of a “washing machine” using Stateflow.

OBJECTIVE

When the power supply is available, the system should be activated.
When the water supply is not available. the process should be stopped and indicated through the LED.
The soaking time should be 200s, followed by a washing time of 100s.
Then rinsing happens for the next 20s and dryer runs for 50s.
finally finished LED should be turned on after the completion of the process.

STATEFLOW CHART

Firstly chart block is selected and entered into the chart environment.
State's are selected according to our design.
State blocks are created with proper names and state actions.
The below diagram shows the chart for the washing machine model

There are 8 blocks, with names start switch, filling, soaking, washing, rinsing, dryer, finish, and stop. we have 2 inputs - power, water, and 8 outputs - x, a, b, c, d, e, f, g.
The direction of the arrow is important ie. from which block to another one.
Here we have given the conditions for power, water ([power==1]) and messege names (after(200,sec)) for delay purpose.

EXPLANATION

When both the power and water conditions are satisfied ie. [power/water==1], the process works and gets completed.
when anyone's condition is not satisfied ie [ power/water~=1], the process does not work and ends at stop block.
After both conditions are true [power/water==1] soaking process will take place for 200 sec, then washing for 100 sec, then rinsing for 20 sec, then dryer for 50 sec, and finally the process finishes.

COMPLETE MODEL

The input power, water are connected to constants, and these are connected with the icons , such as 1 for check and 0 for Ex.

The outputs are connected with corresponding displays and lamps. where displays are used for displaying values 0 and 1, the lamps are used for indicating their present state and for clear understanding.
further explanations are done with the following output diagrams.
Generally, green lamps indicate the present state of the process while the red indicates off state ie. not occurring or happening.

OUTPUT 1 - When any one input or both are not satisfied, the process does not work and it stops with the indication lamp. only the startswitch and stop lamp are green.

OUTPUT 2 - When both the input are satisfied the startswitch , fill lamps are green

OUTPUT 3 - After filling soaking occurs for 200s. startswitch and soak lamps are green

OUTPUT 4 - Then washing occurs for 100 s.

OUTPUT 5 - Rinsing for 20 s.

OUTPUT 6 - Dryer for 50 s.

OUTPUT 7 - The process is completed leaving startswitch and finish lamps in green.

RESULT

Thus the control logic of a “washing machine” using Stateflow is implemented.

2. AIM

To make a Simulink chart for the “Gear shift” logic and to implement the Stateflow.

OBJECTIVE

Speed Range(kmph) Gear

0 to 15 1

16 to 25 2

26 to 40 3

41 to 60 4

Above 61 5

According to the input speed range, the gear numbers should be displayed.

STATEFLOW CHART

There are 6 blocks with names engineon, gear1, gear2, gear3, gear4, gear5, 1-input (speed), and 6-outputs, p, a, b, c, d, e.
The speed conditions according to directions are conditioned.
when 0 < speed <= 15, gear1 block should be active.
when 16 >= speed <=25, gear2 block should be active.
when 26 >= speed <=40, gear3 block should be active.
when 41 >= speed <=60, gear4 block should be active.
when speed > 61, gear5 block should be active.

COMPLETE MODEL

The constant is given as the input (speed) to the chart.
The knob is connected to the constant block which helps us in varying the speed range from 0 to 100 during simulation.
Speed display and circular gauge are connected to the constant, so when we are varying the input speed through the knob, input speed is displayed.
The gear display is connected to the chart, so according to the logic inside the chart, the gear number is displayed.
The displays are used for observing the present state of the process.
The stop time for this simulation is set to inf.
the above diagram shows the initial state when speed is 0 and the engineon block inside the chart is active.
from the below outputs, we can observe that according to the speed variations the gear number varies.

OUTPUT 1 - speed range 1-15 || gear1