1. P07307: Controls for Dynamic Suspension
Mark Lifson Project Manager
Todd Simon Technical Lead
Kapil Chandersen Engineer
Khue Ho Engineer
Sponsor: After Hour Racing LLC

2. P07307: Design Concept Shock position Coil-over spring
MR shock replacing the mechanically adjustable shock
Rear right tire

3. P07307: Project Description
Develop a Dynamic Suspension System
- controls the damping co-efficient on a sprint race car
- responds to significant track conditions e.g. banking degree, corner radii, roughness etc.
- suspension system controlled through adjustment of rear right shock
- uses magneto rheological fluid to dynamically adjust the damping co efficient
- sensors will consist of 2 accelerometers mounted: center of gravity & front right wheel
Gives a better control over the sprint car and hence win races
Key high level customer needs / engineering specs:
- Basic Requirements: Max value for current of approx. 1A
Response time ≈ 25ms
Power consumption < 50 watts
System weight < 20lbs
- General Dynamics: Matches the valving requirements for regular shocks (1-6)
Max. damping co-efficient ≈ 240 8in/sec
Min. damping co-efficient ≈ 50 8in/sec
- Easy to modify: System parameters can be easily modified before the race begins

4. P07307: Technical Risk Assessment
Risks:
Ability to accurately sense turns
Ability to sense bumps with front, right wheel
Determination of shock response time
Possible system lockup
Proposed Mitigations:
Add yaw rate sensor to detect turns
Determine response time through shock dyno or in the final implementation on the car
Add software logic to return shock to “safe” state and LED indicator

5. P07307: Product Development Process Phase
Phase 0/1: SD I -planning, concept development, system-level design
Phase1: Detail design- finalizing full system design/ PCB layouts/ cabling
Phase 2: Testing & refinement- Assembly of PCB, system interfacing, bench testing
Phase 3: Integration into car and testing
Current Phase of Project Development 1 2 3
MSD I
MSD II

6. P07307: Current State of Design
Design is feasible and meets most customer requirements except:
Bump sense: may not sense during power sliding
Design meets all engineering specifications for the full system and subsystems except:
Response time: could be over 25ms
Available project budget is $1000
Project BOM budget: $740
Extra evaluation board for demo/bench test: $150-$200
Mitigations for non-compliances
Can still respond to turns and bumps in straightaway

7. P07307: Budget Distribution

8. P07307: MSDII Project Schedule Milestones
Mar 2: Order Materials and Components
Mar 23: Finalize full Detailed Design (PCB Layout)
Mar 30: Machine Shock Fixtures & Order PCBs
April 13: Assemble and Bench Test PCBs (system with rough software)
April 20: Software Interfacing & Data Collection on Tensile Tester
April 21: System Case Mounting, Field Testing
April 28 (end of 7th week): Overall software integration for Control System
May18: Documentation, Final Project Review