Week - 4

                            Simulink for Mechanical & Electrical Engineers

• To implement control logic of a “washing machine” using Stateflow.
• To Make a Simulink chart for the “Gear shift”.

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

Objective:- 

To implement the control logic of a “washing machine” using Stateflow from the given sequence: 

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

Description:-

• A washing machine is a home appliance used to wash laundary. Before we start the machine we need to consider the load of the clothes, such as how big the load is (small, medium, big, extra large), what temperature the water will be for the wash and the rinse cycles(hot/cold,room teperature, warm/cold) and also the machine running cycles(for how many minutes based on clothes).
• Initially fill the tub with clothes, basedon the load  or by manually fill the tub with water. Along with the water detergent is also added.Then once the water is filled sufficiently, the machine starts stirring the clothes continously in both the directions.
• After few cycles of rotation, the washer drains the water and starts to spin the clothes in order to remove the remaining water from the clothes & aswell as the tub. 
• Similarly, this process is repeated in order to rinse out the soap . Then again finally it flushes all the water out through drain house.
• Finally the spin is ON such that all the clothes inside gets dry to their maximum. 

Stages of washing machine are;

a. Soaking

b. Washing

c. Rinsing

d. Drying

Model-1:

Logic-1:

•   Logic that shows the washing machine process step-by-step without OFF condition. 

Explanation: -

• Firstly, we need to create a logic for the machine to RUN. For this create a Chart by using 'CHART BLOCK' to define the logic of a Washing Machine.
• In order to start with logic, in the charts from the left toolbar drag and drop the 'STAGE'.
• So, the first stage is the Power Supply. The power is used to control the ON & OFF the machine. If the power is ON, the process follows step by step. Here Power is denoted by ‘P’.
• The next stage is the 'Water Supply' & represented by ‘W’. Here the water is filled based on the requirement.
• Between the power supply and water supply there is a condition that controls the process.i.e., if power is equal to 1 which means the power is ON. If the power is ON, the Water Supply will start and when the power is at 0, then the it set to OFF, then there won’t be any supply.
• The third stage is the Soaking Stage i.e., Soak(S). This stage is activated only if the above conditions are in ON condition. In this stage the clothes are soaked once the water is filled. The condition here is if S=1 the state is going ON, The Soaking time is around 200sec.
• The fourth stage is the Washing Stage i.e., Wash(W). Here as per the given condition the clothes are washed after 200sec of soaking. As per the given criteria, the washing time is around 100sec.
• The fifth state is the Rinsing Stage i.e., Rinse(R). In this stage all the water is drained out completely. When this stage is running the condition is represented as ‘R=1’. After 100sec of washing time the clothes are rinsed for 20sec.
• The sixth stage is the Drying Stage i.e., Dry(D). When this stage is running the condition represented is ‘D=1’i.e., the clothes are dried in this case. This drying of clothes takes place after 20sec of rinsing.
• Once this stage is stopped, it goes to the final stage that is ‘Finish Stage’ i.e., Finish(F). After 50sec of drying clothes the process reaches to the final stage that means the process ends and the machine is set to OFF.
• Here the main logic ends.
• In order to provide the input parameters like power and water to the washing machine, choose two constant block naming ‘Power Supply’ & ‘Water Supply’. These constant blocks are controlled by a Slider Switch. Here ON & OFF are set to tune the parameters by connecting to the respective constant block.

• So, the inputs are specified.
• To the other side of the chart block, create the required output parameters. The output parameters are Power(P), Water(W), Soak(S), Wash (Wa), Rinse(R), Dry(D), and Finish(F).
• Now, from the tool bar select SIMULATION > go to PREPARE > go to drop down menu and select ‘SYMBOLS PANE’ from Configuration and Simulation option.

• For all the parameters we need to define the type of data it is, like the Power(P) is the Input Data, Finish(F) is the Output Data etc.
• After declaring all the variables to their respective data type, each one is connected to the display as shown in the model.
• Finally, the ‘LAMP BLOCK’ is used to identify the stage process of the machine. For this drag and drop the Lam block and double click on the block. Now select one parameter for each lamp block and link the respective signals to them. Also set the State & Colour i.e. if the state=1 then the lamp should indicate Green colour and if the  state=0 then the lamp should indicate Red colour.

• Now, the complete model setup is done.
• As per the given conditions we need to change the stop time to observe the LED glow based on their respective stages.
• Finally RUN the simulation as per the given time conditions.

Results: -

Stages of Washing Machine:

Considering Stop time=100sec(baseline), Power Supply=1 (ON) and Water Supply=0 (OFF).

From the above image it is observed that the power supply is kept ON and Water is kept OFF. As per the given condition when the water supply is kept OFF the whole process will not begin. Hence, Lamp assigned for the power glows up green and rest remains red.

Soaking:

When both power and water supply are turned ON and the simulation is made to RUN for 100sec.  It is observed that the soaking process is happening and hence the Lamp glow Green for power, water and soaking. Rest all the lamp remains Red.

Washing:

As per the given condition it is observed that as the water supply is turned ON, and the simulation is made to run for around 250sec(as soaking takes place for 200sec) the washing process has begin after the soaking process ends. Hence lamp for washing also glows up Green and rest remains Red.

Rinsing:

Once after completing the washing process for 100sec, then immediately Rinsing process begins. Simulation is made to run for 320sec as per the condition. Hence the Lamp also glows Green for the Rinsing stage and the last stwo stages remain Red.

Drying:

As the process of Rinsing ends, immediately the next stage Drying is carried out and made to run for 350sec. Hence the Lamp for the Drying also glows Green and the final stage remains Red.

Finished:

The above image shows the final stage of the complete process for the Washing Machine. The above model completely satisfies the given conditions and after finishing all the stages of the machine the 'Finish' Lamp glows Green. Hence all the stages of washing machine are performed using the given condition.

Model-2

logic:-

Explanation: -

• Firstly, we need to create a logic for the machine to RUN. For this create a Chart by using 'CHART BLOCK' to define the logic of a Washing Machine.
• In order to start with logic, in the charts from the left toolbar drag and drop the 'STAGE'.
• So, the first stage is the Power Supply. The power is used to control the ON & OFF the machine. If the power is ON, the process follows step by step. Here Power is denoted by ‘P’. 
• The next stage is the 'Water Supply' & represented by ‘W’. Here the water is filled based on the requirement.
• Between the power supply and water supply there is a condition that controls the process.i.e., if power is equal to 1 which means the power is ON. If the power is ON, the Water Supply will start and when the power is at 0, then the it set to OFF, then there won’t be any supply.
• The third stage is the Soaking Stage i.e., Soak(S). This stage is activated only if the above conditions are in ON condition. In this stage the clothes are soaked once the water is filled. The condition here is if S=1 the state is going ON. The Soaking time is around 200sec.
• The fourth stage is the Washing Stage i.e., Wash(W). Here as per the given condition the clothes are washed after 200sec of soaking. As per the given criteria, the washing time is around 100sec.
• The fifth state is the Rinsing Stage i.e., Rinse(R). In this stage all the water is drained out completely. When this stage is running the condition is represented as ‘R=1’. After 100sec of washing time the clothes are rinsed for 20sec.
• The sixth stage is the Drying Stage i.e., Dry(D). When this stage is running the condition represented is ‘D=1’i.e., the clothes are dried in this case. This drying of clothes takes place after 20sec of rinsing.
• Once this stage is stopped, it goes to the final stage that is ‘Finish Stage’ i.e., Finish(F). After 50sec of drying clothes the process reaches to the final stage that means the process ends and the machine is set to OFF.
• Here the main logic ends and the other connections are same as model-1
• The only change between model-1 and model-2 is, in model-1 for every stage the led glows green and remains green even after the process is finished. Whereas for model-2, the Led glows Green for the active stage and rest remains in Red.

Result:- 

• The result for the model-2 is almost same as the model-1.  It is observed that when both power and water supply are in ON condition, the led lamp glows green and the soaking starts happening.
• As soaking time is around 200sec, after 200sec the soaking process ends and washing process begins i.e., Led for Soakin process turns Red and Led glows Green for Washing.
• Similarly, afte 100sec of washing the process ends and the led glows red which also starts the next process and hence Led for Rinsing gows Green.
• After 20sec of rinsing, the next stage is drying. The drying stage lamp glows Green and the lamp for drying goes Red.
• Finally, after 50sec of drying the process stops and hence the washing process is completely done. 
• Therefore, the Lamp for Finish glow green which indicates that the process is done.

Soaking stage:

Washing stage:

Rinsing stage:

Drying stage:

Finish: 

Conclusion:-

Therefore, the control logic of a “washing machine” using Stateflow is carried out as per the given imput parameters. After all the processes have completed the final Led glows to Green indicating that the processes has ended. 

To Make a Simulink chart for the “Gear shift”.

Objective:-

To 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.  

Description:-

Gears are mainly used for transmitting power from one part of a machine to another. Lower gear ratios offer more torque but less speed, while the higher gear ratios offer less torque but less speed. The manual transmissions consist of three shafts with constantly engaging gears of different sizes. The input shaft connects to the engine by means of clutch. The counter shafts is constantly meshed with the input shaft and has multiple gears. The output shaft connects the countershaft to the driven shaft and eventually to the wheels.

Model -

Logic-

Explanation: -

• Here, first we need to create a logic for the gear shifting. For this create a Chart by using 'CHART BLOCK' to define the logic.
• In order to start with logic, in the charts from the left toolbar drag and drop the 'STAGE'.
• Initially as per the given conditions, five states are defined i.e., Gear_1, Gear_2, Gear_3, Gear_4 and Gear_5.
• Based on the given speed parameters, we need to provide the necessary conditions between the states.

             Speed Range(kmph)               Gear

                         0 to 15                           1

                         16 to 25                          2

                         26 to 40                          3

                         41 to 60                          4

                         Above 61                        5

• Initial, for the speed of 0-15kmph it is first gear. The condition b/w Gear_1 & Gear_2 is specified as if the speed is greater than 15 then it should be shifted to second gear and if not, it remains in the first gear.
• For the speed range of 16-25kmph, the second gear is maintained. The condition b/w Gear_2 & Gear_3 is specified as if the speed is greater than 25 then it should be shifted to third gear and if not, it remains in the second gear.
• Until the speed is 25kmph it remains in second gear and once the speed reaches to 26kmph it changes to third gear.
• The condition b/w Gear_3 & Gear_4 is specified as if the speed is greater than 40 then it should be shifted to fourth gear.
• The speed maintained in fourth gear is 41-60kmph. The condition b/w Gear_4 & Gear_5 is specified as if the speed is greater than 60 then it should be shifted to fifth gear.
• Here the main logic ends.
• On the left side of chart block a Constant Block is connected. It is represented as the Accelerator/speed. In order to control the variation of speed a Slider Block is connected to the ‘Accelerator/speed’ i.e., constant block.

• In the slider block the scale is set to the range of 0-150 and connected to the Accelerator(speed) i.e., constant block
• To the other side of the chart block, create the required output parameters i.e., Gear(G).
• Now, from the tool bar select SIMULATION > go to PREPARE > go to drop down menu and select ‘SYMBOLS PANE’ from Configuration and Simulation option.

• For all the parameters we need to define the type of data it is i.e., the Speed(S) is the Input Data, and Gears(G) is the Output Data.
• After declaring all the variable to their respective data type, it is connected to the display as shown in the model.
• One signal from the input acceleration is connected to the scope and the other signal from the output is also connected to the scope in order to compare the speed with gear shifts.
• Now, the complete model setup is done. It is made to RUN the model with run time as 10sec.

Results: -

• By implementing the given logic for shifting of gears it is observed that, on varying the acceleration or speed it shows the gear shift w.r.to. the range of speed.
• It s observed that between the range of 0 to 15 kmph, the dispaly shows that gear is in First gear. On varying the values between the specified range is displays Gear=1.
• When the speed is increased to 16kmph, it is observed that the gear is shifted to the Second gear. For the range of 16 - 25kmph the gear values displays is 2.
• Similarly, as per the specified speed ranges, the gear shifts are shown in the display block for all the cases.
• The above logic is made in such a way that for each and every gear shift there is a specific speed range given as input. Based on these speed variations the Gear value is displayed.

Gear-1  Speed Range = 0-15kmph

Gear-2  Speed Range = 16-25kmph

Gear-3  Speed Range = 26-40kmph

Gear-4  Speed Range = 41-60kmph

Gear-5  Above 61kmph

Conclusion:- 

By creating the Gear Shift Logic and giving the speed vs gear conditions, the gear shifting is observed. The gear shift corresponding to the gien speed have been simulated. Therefore,  control logic of a “washing machine” using Stateflow is implemented and Simulink chart for the “Gear shift” logic is also done.