PROJECT DEVELOPEMENTFUZZY SYSTEM• Creating membership function using MATLAB application. • 4 input membership function. • 1 output membership function. • Defuzzification using MAMDANI style.
Cont. ……• Create rule evaluation.• Choose more usable rule for our traffic light system. • Do try and error to find rule that give more logic condition. • Cut any rule that give same result. Testing fuzzy system using MATLAB to check condition of our system before implement in PLC.
MEMBERSHIP FUNCTION (MATLAB)Input Membership Function
Input MFMembership variable : very low, low, medium, high, very high.Very low [0 0 2.5]Low [0 2.5 5]Medium [2.5 5 7.5]High [5 7.5 10]Very high [7.5 10 10]
Output Membership Function
Output MFMembership variable : very low, low, medium, high, very high.Very low [0 0 10]Low [0 10 20]Medium [10 20 30]High [20 30 40]Very high [30 40 40]
Evaluation of Rule
Evaluation of RULEUse MAMDANI style. Use min-max. Difuzzification using centroid of gravity. On our project we have use 45 rules to make our system function properly.
Creating Fuzzy using Cx-ProcessToolCreate fuzzy block diagram. Because our output for fuzzy is four, so we need to construct four fuzzy block diagram. Create user link table to read/write (communicate) between LCB (Cx- Process) and CPU PLC (Cx-Programmer).
Cont.Need to create input MF, up to 8 input. (but in our project we just use 4 input; X1, X2, X3, X4.)Input membership variable: NL: 0:2500 NS: 0:2500:5000 ZR: 2500:5000:7500 PS: 5000:7500:10000 PL: 7500:10000
Cont.Need to create output MF, up to 2 output; Y1 and Y2.But, in our project just use 1 output; Y1.Use horizontal singleton.Output membership variable: NL: 5000 NS: 10000 ZR: 15000 PS: 20000 PL: 25000
Cont.RULESRules express experience and know-how in IF- THEN statements. For example, IF (youre close to the car in front of you) & (youre going very fast) THEN (you have to step on the brake very hard).Up to 64 rules.In our project using 45 rules.Up to 8 conditions can be set for inputs X1 to X8, and up to two conclusions can be set for outputs Y1 and Y2.
Cont. Conditions The labels that will be used for inputs X1 to X8 are listed in order separated by colons. For example, if label NS is used for input X1 and labels ZR, PL, PL, NS, ZR, PL, and PL are likewise used for inputs X2, X3, X4, X5, X6, X7, and X8, then NS:ZR:PL:PL:NS:ZR:PL:PL is specified.
Cont. Conclusions The labels that will be used for outputs Y1 and Y2 are listed in order separated by colons. For example, if ZR is used for output Y1 and PL is used for output Y2, then ZR:PL is specified A slash is placed between the conditions and conclusions. For example, the above rule would be specified as follows: NS:ZR:PL:PL:NS:ZR:PL:PL/ZR:PL
Cont. Set a hyphen for inputs or outputs for which labels are not set. For example, to set NL for input X1, PL for input X2, and ZR for output Y1, then the rule "IF (Input X1 is NL and Input X2 is PL), THEN (Output Y1 is ZR)" would be specified as follows for ITEM 101: NL:PL:-:-:-:-:-:-/ZR:-
Fuzzy Block Diagram
Creating ladder diagram (cx-programmer) used to create ladder diagram for input and output of traffic light system. Use a discrete sensor (photoelectric switch) to detect presence vehicle for each junction. Use counter in ladder to count vehicle which detect by photoelectric switch. Data from counter is transform to LCB (Fuzzy system) to process by fuzzy system. Data from LCB then send to PLC to generate output for traffic light. Data from LCB is Hex, so it must create a ladder diagram to make is useful for generate timer for traffic light system.
Testing & Result Using MATLAB Guide to test using Matlab: Put number of vehicles for each junction at bottom pages and look for output at top right pages.Put number ofvehicles here
Cont. Look for output here
Result from Matlab
Testing in real system (PLCwith Fuzzy system)Guide to testing;The car come from each junction with random number.The car must past the first sensor and stop before the second sensor.When traffic light going to green, car at the junction with green lamp will move until past the second sensor.