Testing & Diagnosis
Behavioral airflow
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challenge
• Observed a large discrepancy between the simulated and measured drag coefficients, indicating unexpected aerodynamic behavior
• Needed to understand how air flowed over and around the vehicle under real conditions to identify sources of drag
• Required a practical testing method to pinpoint aerodynamic inefficiencies and areas for design improvement
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approach
• Instrumented the solar car’s aeroshell with tufts (light strings) to visualize airflow direction and behavior during testing
• Conducted behavioral airflow tests on a closed road highway to capture high-speed photographs and video evidence of airflow movement
• Analyzed tuft motion to identify regions of separation, turbulence, and reversed flow across the shell
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solution
• Discovered a “parachute effect” at the leading edge, where tufts were pulled inward, indicating unwanted air ingress
• Identified a continuous gap between the upper and lower shells, contributing to drag and turbulent separation
• Determined that the rough aeroshell surface and localized turbulent zones further degraded aerodynamic performance
• Used test results to pinpoint areas for refinement in sealing, surface finish, and shell geometry to reduce overall drag and improve aerodynamic efficiency
Dynamic testing
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challenge
• Demonstrate compliance with American Solar Challenge performance rules for Figure-8, Slalom, and wet-surface braking
• Develop a test plan for a closed-road facility while ensuring driver and bystander safety
• Achieve specified performance targets (≤ 8.0 s/side Figure-8, ≤ 11.5 s Slalom, ≥ 4.72 m/s² wet braking) to pass scrutineering for the Formula Sun Grand Prix competition
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approach
• Developed a formal closed-road test plan specifying facility layout, safety briefings, observers, and safety mitigations
• Executed course setups per ASC geometry (Figure-8 cones, 18 m slalom spacing) and prepared the braking zone with controlled wetting for repeatable wet-stop runs
• Varied tire pressure to establish to establish performance/efficiency tradeoffs
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solution
• Collected, documented, and analyzed telemetry and video for all runs
• Figure-8 and Slalom runs consistently met time targets with clear margins (all runs ≤ required times)
• Wet braking tests produced average deceleration above the ASC minimum (average ≥ 4.72 m/s²), confirming stopping performance on a wetted surface
Tracker vehicle optimization
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challenge
• Use an autonomous line-following car that could not reliably stay on track and change the poor turning logic
• Gain a faster response from the vehicle that could stay on the course and complete the loop faster than the other groups
• Alter sensitivity and control code to achieve consistent, precise, and fast behavior
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approach
• Redesigned the control logic to optimize wheel speed balance and improve turning dynamics to stay on the line
• Implemented logic for lap counting and automatic stopping after the three laps
• Iteratively tested and tuned system parameters to find an optimal sensitivity and response level.
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solution
• Developed a higher speed and more stable control algorithm that eliminated erratic reversing and improved turn precision
• Achieved consistent track-following performance and automated lap tracking logic
• Placed in the top 3 for fastest vehicles around the loop