1. CAMP-G/Matlab Vehicle Crash Test
Sukhbir Hundal
ME 270
LAB 1
11/1/07

2. 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.

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

4. Verify CAMP-G/Hand Derivation
There are four differential equations seen in the diagram!
Verified State Space Equations are Correct!

5. CAMP-G Generate Model/Matlab
Initial Condition: Q4IN= 0; Q10IN= 0; SF =0 k2 = N/m; b2 = Ns/m k1 = N/m ; b1= 500 Ns/m
Step 4: Received four files in Matlab: campgequ.m, campgmod.m, campgnum.m, campgsym.m
Step 5: Added Physical Parameters into Matlab – campgmod.m file with Initial Conditions
k2 and b2 are Bumper k1 and b1 are seat belt

6. Initial Condition: Displacement (car & dummy) at 25 mph and 55 mph
Figure 1: displacement vs time at 25 mph Figure 2: displacement vs time at 55 mph
Comment: Dummy survives impact at 25 mph but collides into the windshield at 55 mph!

7. Initial Condition: Force on Dummy between Seat Belt at 25 mph and 55mph
Figure 3: force vs time at 25 mph Figure 4: Force vs time at 55 mph
Comment: Chest of the dummy sustains a force under 6670 N so he
survives at 25 and 55 mph!

8. CAMP-G Generates Model/Matlab
MY DESIGN Condition (1 seat belt) Changed the following: k2 = N/m; b2 = 900 Ns/m k1 = N/m; b1 = Ns/m
CAMP-G Generates Model/Matlab
Step 4: Received four files in Matlab: campgequ.m, campgmod.m, campgnum.m, campgsym.m
Step 5: Added Physical Parameters into Matlab – campgmod.m file with MY DESIGN Conditions
k2 and b2 is bumper k1 and b1 is seat belt

9. MY Design Condition: (1 seat belt) Displacement (car & dummy) at 25 mph and 55 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!

10. 2a. MY Design Condition: (1 seatbelt) Force on Dummy between Seat Belt at 25 mph and 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!

11. CAMP-G Generates Model/Matlab
MY DESIGN Condition (2 seat belts) Changed the following: k2 = N/m; b2 = 900 Ns/m k1 = 2* N/m; b1 = 2*10000 Ns/m
CAMP-G Generates Model/Matlab
Step 6: Received four files in Matlab: campgequ.m, campgmod.m, campgnum.m, campgsym.m
Step 7: Added Physical Parameters into Matlab – campgmod.m file with MY DESIGN Conditions
k2 and b2 is Bumper k1 and b1 is seat belt

12. 2b. MY Design Condition: (2 seat belts) Displacement (car & dummy) at 25 mph and 55 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!

13. 2b. MY DESIGN Condition: (2 seatbelts) Force on Dummy between Seat Belt at 25 mph and 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!

14. 3. Initial Condition: Displacement/Force at “Critical” Maximum Velocity = 30 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!

15. 4a. Initial Condition: Displacement and Force at 25 mph without seat belt (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!

16. 4b. Initial Condition: Displacement and Force at 40 mph without seat belt (k1=10E-10 and b1 = 0)
Figure 17: displacement vs time at 40 mph Figure 18: force vs time at 40 mph
Comment: Dummy collides into the windshield within 0.07 seconds but
has ZERO force on his chest!

17. 4c. Initial Condition: Displacement and Force at 55 mph without seat belt (k1=10E-10 and b1 = 0)
Figure 19: displacement vs time at 55 mph Figure 20: force vs time at 55 mph
Comment: Dummy collides into the windshield within seconds
but has ZERO force on his chest!

18. Step Response/Camp-G: Initial Condition:
Step 8: Run campnum.m to find the step response and verified with Simulink (next slide) to make sure it is correct:
Figure 21: Step Response of the Model

19. Simulink/Matlab Initial Condition:
Step 9: Run Simulink in Matlab to find the step response, the following is the Simulink block diagram of the model:

20. Simulink/Camp-G Initial Condition:
Simulink Figures Output T1 and T2:
Figure 22: Output Figure 23: Output 2
The Step Response and Simulink are identical so the results are correct!!

21. 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