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

After all the processes have completed turn on the finished LED

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.

Answer-

process:

1.Start simulink and create a blank model.

2.Search for chart block in the stateflow category of library browser.

3.Open the chart block and select the junction feature from the stateflow window.

4.Control logic for washing m/c is such that it should soak the water for the first 200sec followed by washing time of 100sec. Rinsing the water for the next

20sec followed by drying time of 50sec.

1. After finishing the control logic run the STATEFLOW and check the sequence of operation for 370sec

Block Used

1. Chart

A finite state machine is a representation of an event-driven (reactive) system. In an event-driven system, the system responds to an event by making a transition

from one state (mode) to another. This transition occurs if the condition defining the change is true.

1. Display

The Display block shows the value of the input data. You can specify the frequency of the display. For numeric input data, you can also specify the format of the

display.

1. Constant

The Constant block generates a real or complex constant value signal. Use this block to provide a constant signal input.

1. Lamp

The Lamp block displays a color indicating the value of the input signal. You can use the Lamp block with other Dashboard blocks to build an interactive

dashboard of controls and indicators for your model. You can specify pairs of input values and colors to provide the information you want during the simulation.

1. Rocker Switch:

The Rocker Switch block toggles the value of the connected block parameter between two values during simulation. For example, you can connect the Rocker Switch block to a Switch block in your model and change its state during simulation.

Logic Explanation

A Rocker switch from the dashboard library is used with a constant to supply the power and as water supply. A lamp is used to indicate the power status & water status. The power status is checked at the entry for every

state and the water supply is checked for the soaking and the rinsing process. The timing for each state is as per the given inputs. The status of the running process can be seen by the glowing lamp corresponding to the process name.

In the above control logic first state is created with 2 conditions for power supply .

One is with power supply available(PowerSwitch==1)and second with water supply available 

(W==1).If the power supply at entry is 1 and water supply is on, then machine will get activated and start the next process of operation.

Next 4 Operation states have been created in flow order Soaking,Washing,Rinsing,Drying with their time of operation as 200sec for a soak,100sec for wash,20

sec for rinse & 50sec for dry.Entry and exit condition of the state are kept as 0 & i.e at entry of operation states it is 0 and as operation completes it is 1 for every states.

After all process has done washing machine completed LED will glow and we can shut the machine off.

Here,

PowerSwitch & W(water supply) is as input given while all other like Washing_State, D(dryer), Wa(washing), S(soaking), R(rinsing), Washing_Completed are all output given.

Complete Simulink Model, Showing that the washing process is completed

 Here all LED glown as Green means all process has been completed and all display output as 1.

Simulink Model, Showing that the washing process is completed & Rinsing is going on.

Here Red light means operation is not completed and green LED shows operation is completed which is also check from display box as output 1.

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. 

Part II : IMPLEMENTATION OF CONTROL LOGIC FOR GEAR SHIFT USING STATEFLOW

PROCESS:

1.Start simulink and create a blank model.

1. Search for CHART block in the stateflow category of library browser.
2. Open the chart block and select the various features from the stateflow window.

4.Control logic for gear shift is such that it should change the gear when the speed increases of decreases automatically.

5.After finishing the control logic run the stateflow and check the gear shift operation for an infinite time.

Blocks Used

1. Chart

A finite state machine is a representation of an event-driven (reactive) system. In an event-driven system, the system responds to an event by making a transition

from one state (mode) to another. This transition occurs if the condition defining the change is true.

1. Display

The Display block shows the value of the input data. You can specify the frequency of the display. For numeric input data, you can also specify the format of the

display.

1. Constant

The Constant block generates a real or complex constant value signal. Use this block to provide a constant signal input.

1. Lamp

The Lamp block displays a color indicating the value of the input signal. You can use the Lamp block with other Dashboard blocks to build an interactive

dashboard of controls and indicators for your model. You can specify pairs of input values and colors to provide the information you want during the simulation.

Rocker Switch:

The Rocker Switch block toggles the value of the connected block parameter between two values during simulation. For example, you can connect the Rocker Switch block to a Switch block in your model and change its state during simulation.

Logic Explanation

The speed ranges from 0 to 100 and the slider is used to send the input. The 1st gear has speed values from 0 to 15 so the entry condition for the 1st gear is 0<=speed and speed<=15 and the exit condition is when the speed greater than 15.

 Similarly for 2nd gear, the entry condition is 16<=speed and speed<=25 the exit condition is when speed<16 and speed>25. In the same way for each gear, the entry and the exit condition are specified and the out is mapped to the lamp and the display block.

1. In the above control logic , first Engine is started from input switch E=0/1 through Rocker switch which is power switch to make engine ON.Then next Gear_Shift_logic implemented through following states. 

1. Five Gear State is created with state condition of gear (G) 1,2,3,4and 5 respectively and their transition is connected with speed range condition as shown.

3.The transitions condition for the gear shift is decided as  

             Speed>15 shift to G=2

             Speed>25 shift to G=3

             Speed >40 shift to G=4

             Speed>60 shift to G=5 when the speed is increasing from 0-60 kmph

similarly in reverse direction             

              Speed<60 shift to G=4

             Speed<40 shift to G=3

             Speed<25 shift to G=2

             Speed<15 shift to G=1 when the speed is decreasing from 60-0 Kmph

While simulating Gear_Shift_logic , Engine [E==1] condition given with various speed change values.

At speed 48kmph which is above 40kmph gear 4 is implemented and Gear_fourth  LED is glow green and display output as 1.

And thus all condition simulated through stateflow chart successfully.