Week - 4

WEEK-4

1.Implement control logic of a “washing machine” using Stateflow as per given sequence:

• If the power supply is available, the system gets activated
• If the Water supply is not available, stop the process & indicate through LED
• Soaking time should be 200s followed by Washing time of 100s.
• Then rinsing happens for next 20s & dryer runs for 50s

Solution:

WORKING PRINCIPLE OF A WASHING MACHINE:

A washing machine by spinning at 800-1600 rpm helps soap and dirt with it to leave the surface of the cloth via centrifugal force and into outlet pipes hence utilizing centrifugation to both clean and partially dry the clothes loaded in it. Thus, the processes are electrically controlled, such as the drum, valves, pump, motor and heating. The valve opens again and the dirty water drains out of the drums. The pump works to help get rid of the water. The valve lets clean water in again into the drums. The four processes are:

SOAKING:

It is used to dip clothes in detergent water to remove dirt from the clothes. In this function customer need to select soak from a panel. Soak - This function is available with wash timer, In 42 min of washing 27 min is soak and 15 min machine will wash the clothes.

WASHING:

During the wash cycle, a large plastic agitator (green) turns around, moving your clothes through the water. When the wash is finished, the pump drains the water from the outer drum.

RINSING:

The dirty, soapy water is drained, then the washing machine is refilled and your clothes are "rewashed" in clean water. Spin: All the water is drained completely, then your clothes are spun very fast and excess water is removed thanks to centrifugal force.

DRYER:

They work by pushing warm dry air through your wet washing to extract moisture, then cooling the now humid air in a heat exchanger to condense the moisture, which is collected in a tank or pumped down the drain. The (now dry) air is reheated and the cycle repeats.

1) STATE-FLOW:

Systematic solution of a problem is possible with sequential, unambiguous and realizable finite process step set. This set is called “algorithm” and it is one of the most important parts of the programming languages. In this study, it is represented how to learn algorithm by using Simulink Stateflow. In flow diagram-based algorithm learning.

CONTROL LOGIC OF A WASHING MACHINE:

It checks for the extent of dirt and grease, the amount of soap and water to add, direction of spin, and so on. The machine rebalances washing load to ensure correct spinning. Else, it reduces spinning speed if an imbalance is detected. Even distribution of washing load reduces spinning noise.

Stateflow:

The two inputs are given for the power and water supply. Once the inputs are given outputs are displayed by the flow chart as per the given sequence. The system is observed for some time then it is checked and the process is completed by green light as displayed.

Chart and output:

2.Make a Simulink chart for the “Gear shift” logic as per below conditions:

Speed Range(kmph) Gear

0 to 15 1

16 to 25 2

26 to 40 3

41 to 60 4

Above 61 5

Give speed input while the simulation is running & display the gear number.

Solution:

Chart of Gear shift Logic:

Stateflow:

Time and I/O parameters:

Set the stop time to infinite and change the parameters of speed as input and Gear as output using symbol wizard. Use a lamp to describe the Gear shifting with different colours.

Input:

Use the slider gain to give and change the input. Change the slider to change the speed as given in the question.

Output:

Gear_1:

Speed range: 0-15kmph

Input speed: 10kmph

Colour: Green

Gear_2:

Speed range: 16-25kmph

Input speed: 20kmph

Colour: Blue

Gear_3:

Speed range: 26-40kmph

Input speed: 35kmph

Colour: Yellow

Gear_4:

Speed range: 41-60kmph

Input speed: 50kmph

Colour: Red

Gear_5:

Speed range: above 60kmph

Input speed: 70kmph

Colour: Dark Red