CAMP-G/MatlabVehicle Crash TestCAMP-G/Matlab

Vehicle Crash Test

Sukhbir HundalSukhbir Hundal

ME 270ME 270

LAB 1LAB 1

11/1/0711/1/07

Introduction:Introduction:

Purpose: create a design where the dummy would survive from the force caused by the seat belts and avoid hitting the windshield.

system modeled elements: a mass, a dampener, and a spring element

Assumption: Gravity is neglected in the system to keep the model linear

mass as inertial, damping as a resistor, and the spring as a capacitor. The capacitance is 1/K where K is the spring constant.

CAMP-G SystemCAMP-G SystemCAMP-G SystemCAMP-G System Step 1: Generate Engineering Model of RealityStep 1: Generate Engineering Model of Reality Step 2: Enter Bond Graph in Graphical Form:Step 2: Enter Bond Graph in Graphical Form:

VerifyVerifyCAMP-G/Hand DerivationCAMP-G/Hand Derivation

There are four differential equations seen in the diagram!

Verified State Space Equations are Correct!

Initial Condition:Initial Condition: Q4IN= 0; Q10IN= 0; SF =0 Q4IN= 0; Q10IN= 0; SF =0

k2 =k2 = 300000 N/m; b2 = 300000 N/m; b2 = 80000 Ns/m 80000 Ns/m

k1 = 10000 N/m ; b1= 500 k1 = 10000 N/m ; b1= 500 Ns/mNs/mk2 and b2 are Bumper k1 and b1 are

seat belt

Step 4: Received four files in Matlab: Step 4: Received four files in Matlab: campgequ.m, campgmod.m, campgnum.m, campgequ.m, campgmod.m, campgnum.m, campgsym.mcampgsym.m

Step 5: Added Physical Parameters into Matlab Step 5: Added Physical Parameters into Matlab – campgmod.m file with Initial Conditions– campgmod.m file with Initial Conditions

CAMP-G Generate CAMP-G Generate Model/MatlabModel/Matlab

Initial Condition:Initial Condition: Displacement (car & dummy) at Displacement (car & dummy) at

25 mph25 mph and and 55 mph55 mph

Initial Condition:Initial Condition: Displacement (car & dummy) at Displacement (car & dummy) at

25 mph25 mph and and 55 mph55 mph

Figure 1: displacement vs time at 25 mph Figure 2: displacement vs time at 55 mphComment: Dummy survives impact at 25 mph but collides into the windshield at 55 mph!

Initial Condition:Initial Condition: Force on Dummy between Seat Force on Dummy between Seat

Belt at Belt at 25 mph 25 mph and and 55mph55mph

Initial Condition:Initial Condition: Force on Dummy between Seat Force on Dummy between Seat

Belt at Belt at 25 mph 25 mph and and 55mph55mph

Figure 3: force vs time at 25 mph Figure 4: Force vs time at 55 mphComment: Chest of the dummy sustains a force under 6670 N so he survives at 25 and 55 mph!

MY DESIGN Condition (1 MY DESIGN Condition (1 seat belt)seat belt)

Changed the following:Changed the following: k2 = 20000 k2 = 20000 N/mN/m; b2 = 900 ; b2 = 900

Ns/mNs/m k1 = 100000 k1 = 100000 N/mN/m; b1 = ; b1 =

10000 10000 Ns/mNs/mk2 and b2 is bumper k1 and b1 is seat belt

CAMP-G Generates CAMP-G Generates Model/MatlabModel/Matlab Step 4: Received four files in Matlab: campgequ.m, Step 4: Received four files in Matlab: campgequ.m,

campgmod.m, campgnum.m, campgsym.mcampgmod.m, campgnum.m, campgsym.m Step 5: Added Physical Parameters into Matlab – Step 5: Added Physical Parameters into Matlab –

campgmod.m file with MY DESIGN Conditionscampgmod.m file with MY DESIGN Conditions

1.1. MY Design Condition: MY Design Condition: (1 (1 seat belt)seat belt)

Displacement (car & Displacement (car & dummy) dummy)

at at 25 mph25 mph and and 55 mph55 mph

1.1. MY Design Condition: MY Design Condition: (1 (1 seat belt)seat belt)

Displacement (car & Displacement (car & dummy) dummy)

at at 25 mph25 mph and and 55 mph55 mph

Figure 5: displacement vs time at 25 mph Figure 6: displacement vs time at 55 mph

Comment: Dummy survives impact with my design at 25 mph and 55 mph!

2a.2a. MY Design Condition: MY Design Condition: (1 (1 seatbelt)seatbelt) Force on Dummy Force on Dummy

between Seat Belt at between Seat Belt at 25 mph 25 mph andand 55 mph 55 mph

2a.2a. MY Design Condition: MY Design Condition: (1 (1 seatbelt)seatbelt) Force on Dummy Force on Dummy

between Seat Belt at between Seat Belt at 25 mph 25 mph andand 55 mph 55 mph

Figure 7: force vs time at 25 mph Figure 8: Force vs time at 55 mph

Comment: Dummy survives impact of force at 25 mph and 55 mph!

MY DESIGN Condition (2 MY DESIGN Condition (2 seat belts)seat belts)

Changed the following:Changed the following: k2 = 20000 k2 = 20000 N/mN/m; b2 = 900 ; b2 = 900 Ns/mNs/m

k1 = k1 = 22*100000 *100000 N/mN/m; b1 = ; b1 = 22*10000 *10000 Ns/mNs/mk2 and b2 is Bumper k1 and b1 is

seat belt

Step 6: Received four files in Matlab: campgequ.m, Step 6: Received four files in Matlab: campgequ.m, campgmod.m, campgnum.m, campgsym.mcampgmod.m, campgnum.m, campgsym.m

Step 7: Added Physical Parameters into Matlab – Step 7: Added Physical Parameters into Matlab – campgmod.m file with MY DESIGN Conditionscampgmod.m file with MY DESIGN Conditions

CAMP-G Generates CAMP-G Generates Model/MatlabModel/Matlab

2b.2b. MY Design Condition: (2 MY Design Condition: (2 seat belts)seat belts)

Displacement (car & dummy) Displacement (car & dummy) at at

25 mph25 mph and and 55 mph55 mph

2b.2b. MY Design Condition: (2 MY Design Condition: (2 seat belts)seat belts)

Displacement (car & dummy) Displacement (car & dummy) at at

25 mph25 mph and and 55 mph55 mph

Figure 9: displacement vs time at 25 mph Figure 10: displacement vs time at 55 mph

Comment: Dummy survives impact for 2 seat belts at 25 mph and 55 mph!

2b.2b. MY DESIGN Condition: (2 MY DESIGN Condition: (2

seatbelts)seatbelts) Force on Dummy between Seat Force on Dummy between Seat

Belt at Belt at 25 mph 25 mph andand 55mph 55mph

2b.2b. MY DESIGN Condition: (2 MY DESIGN Condition: (2

seatbelts)seatbelts) Force on Dummy between Seat Force on Dummy between Seat

Belt at Belt at 25 mph 25 mph andand 55mph 55mph

Figure 11: force vs time at 25 mph Figure 12: Force vs time at 55 mph

Comment: Dummy survives impact of force from seat belt at 25 mph and 55 mph!

3. Initial Condition:3. Initial Condition: Displacement/Force at Displacement/Force at

“Critical” Maximum Velocity = “Critical” Maximum Velocity = 30 mph30 mph

3. Initial Condition:3. Initial Condition: Displacement/Force at Displacement/Force at

“Critical” Maximum Velocity = “Critical” Maximum Velocity = 30 mph30 mph

Figure 13: displacement vs time at 30 mph Figure 14: force vs time at 30 mph

Comment: Dummy can drive at 30 mph before he hits the windshield of the car!

4a. Initial Condition:4a. Initial Condition: Displacement and Force at Displacement and Force at 25 25

mphmph without seat belt without seat belt (k1=10E-10 and b1 = 0)(k1=10E-10 and b1 = 0)

4a. Initial Condition:4a. Initial Condition: Displacement and Force at Displacement and Force at 25 25

mphmph without seat belt without seat belt (k1=10E-10 and b1 = 0)(k1=10E-10 and b1 = 0)

Figure 15: displacement vs time at 25 mph Figure 16: force vs time at 25 mph

Comment: Dummy collides into the windshield within 0.1 seconds but has ZERO force on his chest!

4b. Initial Condition:4b. Initial Condition: Displacement and Force at Displacement and Force at 40 40

mphmphwithout seat belt (k1=10E-10 without seat belt (k1=10E-10

and b1 = 0)and b1 = 0)

4b. Initial Condition:4b. Initial Condition: Displacement and Force at Displacement and Force at 40 40

mphmphwithout seat belt (k1=10E-10 without seat belt (k1=10E-10

and b1 = 0)and b1 = 0)

Figure 17: displacement vs time at 40 mph Figure 18: force vs time at 40 mphComment: Dummy collides into the windshield within 0.07 seconds but

has ZERO force on his chest!

4c. Initial Condition:4c. Initial Condition: Displacement and Force at Displacement and Force at 55 55

mphmph without seat belt without seat belt (k1=10E-10 and b1 = 0)(k1=10E-10 and b1 = 0)

4c. Initial Condition:4c. Initial Condition: Displacement and Force at Displacement and Force at 55 55

mphmph without seat belt without seat belt (k1=10E-10 and b1 = 0)(k1=10E-10 and b1 = 0)

Figure 19: displacement vs time at 55 mph Figure 20: force vs time at 55 mphComment: Dummy collides into the windshield within 0.055 seconds

but has ZERO force on his chest!

Step Response/Camp-G:Step Response/Camp-G: Initial Condition:Initial Condition:

Step 8: Run campnum.m to find the step response and Step 8: Run campnum.m to find the step response and verified with Simulink (next slide) to make sure it is correct:verified with Simulink (next slide) to make sure it is correct:

Figure 21: Step Response of the Model

Simulink/MatlabSimulink/Matlab Initial Condition:Initial Condition:

Step 9: Run Simulink in Matlab to find the step response, Step 9: Run Simulink in Matlab to find the step response, the following is the Simulink block diagram of the model:the following is the Simulink block diagram of the model:

Simulink/Camp-GSimulink/Camp-G Initial Condition:Initial Condition:

Simulink Figures Output T1 and T2:Simulink Figures Output T1 and T2:

The Step Response and Simulink are identical so the results are correct!!

Figure 22: Output Figure 23: Output 2

Conclusion:Conclusion:• damping and spring is completely necessary in the design of the system in order for the dummy to survive. • The initial condition given in the lab was not sufficient to safe the dummy from colliding into the windshield or from force on the dummy’s chest.• I found the best design where he survives the impact from the wall shown in the figures.•Purpose was an introduction to the software to become familiar with the modeling process