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Today’s knowledge share is about the regulations for FSGP (Formula Sun Grand Prix), ASC (American Solar Challenge), and possibly WSC (World Solar Challenge). We haven’t been to that competition in a while, but it has slightly different sets of regulations. However, it’s just really useful to know that all these regulations are completely fair, but they provide the necessities for the minimum product of our solar vehicle. We have to consider them because that will let us attend competition, but there are also other factors to our design that we have to choose and that the regs will not describe. We have to spec our components to be most effective and any communication is not specified in regs. That’s the main usefulness of this knowledge share, and also that we have taken an 80-page document and give you a high-level understanding of what it comes down to. In general, they’re just awesome experiences so it’s fun to talk about and it’s also a good thing to look forward to attend.

So our agenda; the regs are broken down into 3 components, which are the regs breakdown, the technical breakdown, and operations. We’ll also talk about scrutineering, which is the main component that we need to prepare for when we’re there during competition week. I’ve linked the ASC regs on that page so when this is uploaded, that’s the version we used for this document.

So I’ll go over section 1, the regs breakdown. So what is the purpose of all of this? At the end of the day, we're making a solar car for a variety of reasons, but the competition itself is a way to display our engineering creativity and gain experience in an awesome learning environment, have some friendly competition, and also gain automotive industrial experience because at the end of the day we are driving in these cars, so things like meeting specifications for temperatures and safety. Those are very important and we reflect that in our design, so this competition lets us showcase that. Finally, we’re a solar car team and the innovation in our design is put on display here because we’re all driving EVs that harness energy from the sun and our car particularly is meant to be like a sedan, with four passengers.

The regs just basically say that in other words. The regs then go to talk about administration. FSGP is formula sun grand prix. It happens every year and it’s a track-based competition, so every year we meet in a location that’s determined a year in advance, and is provided to all the teams that register. They also tell us the location and every other year, there’s the American solar challenge, which is another event that happens right after FSGP. We’ll talk about this event more later, but it's basically a race across the states, which is pretty cool. The last one was in 2018, and the next one was supposed to be this summer, but it's being pushed to next summer. During these events, there is a lot going on because we have all these teams and then we have to have what the regs call the administration, which is a tent put up for headquarters and there are various officials during the event. There’s the regulations manager keeping track of all the regulations that are being met, and also looking at penalties that need to be given in various situations. The Event Director, also a management-type position, chief inspector in charge of the team that will be inspecting vehicles. Timekeeper. FSGP is a week-long event, and it consists of 3 days of scrutineering, which is equivalent of testing, and then 3 days of racing. Keeping time and schedule is a subdivision of administration. The way the regulations are applied to are scrutineering, qualifiers and the tour, which are 3 stages of ASC coupled with FSGP.

Then the regs go into safety, and the safety is not just about the vehicle’s electrical or mechanical safety, but about the equipment required and the people who are driving and near the car. Even after passing scrutineering tests, it’s always good to remember that we’re liable for our vehicle and any failures during the entire event. We’re not good just because we passed the tests in scrutineering. We must always be aware of our vehicle and our design must be primarily focused on safety. At the end of the day, we’re putting ourselves in this, which is a crazy amount of risk if safety is not the primary focus. So what does safe mean? It means we have a road-worthy car, so it can actually drive is on the road in the setup that’s used for ASC with the support vehicles and it passes the minimum regs of competition and of course, it maintains the minimum regs plus the regs we have put for other systems not outlined. So every competition, there will be a safety officer, who must be trained in first aid and CPR, so we elect one during the terms for competition. If you are interested in competition, which you should be, that’s a role that someone has to take. They can’t be a driver or team manager, but it’s a very important role because they’re the point of contact in case of a safety concern. We have a safety kit that must be carried in the support vehicles during the entire competition. It’s especially important because there have been lots of instances where a car breaks down and stops and things like fires can happen. The safety kit includes a first aid kit, safety vests; everyone must be wearing one during competition when the car is moving, PPE for battery handling; if there’s a need to replace cells or modules, we need the equipment for that, we need orange cones with us at all times, warning flags, a fire extinguisher (very important), battery material safety datasheet, a battery spill kit (which can be 40 kg of sand and a shovel to apply it) or another method of battery fire containment, and we also need a container for damaged cells. This is the bare minimum listed in the regs, so we have to show up with this equipment. We don’t need to carry this is the vehicle itself, this is for the support vehicles or at the pit during FSGP.

We hear about this competition, and we get an outline of the event a year in advance, and before we can just show up to the event, there’s a lot of paperwork and deadlines to be met. The reason I wanted to bring this up is that we’ve talked to past leads, that have had some sad outcomes because they worked really hard on their car, but they were not allowed to participate because they missed their deadlines for some track fees and forms. In addition, this is actually very important for us as well because we have to include a couple of documents that are technical in nature, so in the initial registration package, we needed to send the PVDR. The PVDR has preliminary information about the electrical systems, batteries, solar cells, the mechanical structure, as well as the battery protection system. There’s another package, the track registration package, which includes the vehicle design report, including a solar report, battery report, protection report, electrical report, and a bunch of mechanical reports. These reports need to be approved in order to compete. We also need to send a team photo, team number (we’ve reserved 24), and a team datasheet, which is a high-level outline of our car, including battery weight and capacity, chassis description, braking architecture, wheel specs, and a list of all the leads.

There's a section in the regs that explains the requirements for the technical documentation required. Any of the hardware leads can send you a copy of our PVDR or VDR if you’re interested. These documents are sent to the scrutineers, who are the people that will inspect the vehicles before competition. They will provide feedback to ensure that our design complies with the regulations. For example, they recommended that we increase the number of thermistors in our BMS based on the number of cells in our battery pack. The PVDR includes roll over and driver impact protection, an overview of the electrical report, electrical diagram, preliminary battery approval form, battery specs, testing plans, and timeline, and solar cell approval form. There also needs to be an engineering build review (mainly for mechanical). Before any documents are submitted, they must review the design with an experienced engineer. The VDR is the main document we are required to provide, which will be heavily reviewed. On ASC’s website during this stage, the status of all the documentation of all the teams is shown. Teams that complete their documentation first are allowed to complete scrutineering first, which provides a time advantage during the race. The VDR includes the mech tech report, the electrical system tech report, the battery tech report, the battery protection report, the battery protection tech report, and the solar cell tech report.

The 3 stages of ASC are scrutineering, qualifiers, and the tour. For scrutineering, we need to get all green status before moving on the qualifiers, or at least blue status. Green status means approved and ready to go. Blue status means we can race, but there are penalties. Scrutineering is a set of tests during the first 3 days. The priority goes to teams who completed their registration forms and vehicle reports first. For the dynamics scrutineering, the tests need to be repeated with each driver. Next is qualifiers, which is the main component of FSGP. We must pass the qualifiers before racing in the tour. The tour is a cross-country event and we must complete a minimum number of laps in FSGP to be allowed to race.

Most of the vehicles are still single-occupant vehicles (SOV), which is the traditional “spaceship“ car design (also called challenger class in WSC). Designed to be light-weight, and much faster than our class, which is a multi-occupant vehicle (MOV). Vehicles in this class are designed to be practical consumer vehicles that carry multiple passengers (also called cruiser class in WSC). Not as many teams make MOVs, but the number is growing. There’s also a class called grandfathered, which means the car competed in the past. These vehicles aren’t ranked but can race for demonstration only.

Technical Regulations

Power

• Solar Collector

  • The three types of solar collectors that are allowed are silicon, gallium arsenide, or multi-junction solar cells. We used silicon solar cells because they are cheaper than the other types.

  • Each solar collector has a maximum allowed area. The limit is 5 m² for silicon solar cells.

  • The use of solar concentrators is allowed, but in that case, the area of the concentrator is measured instead of the area of the solar cells.

  • The solar array can only have 6 different solar cells, which includes cells of different compositions or different sizes. During scrutineering, we are required to provide samples of the cells on the car so they can verify the type of cell.

  • Teams often tilt the array during stationary charging to maximize the efficiency of the array. In this case, the array must be supported by the car, without aid from team members.

  • Dust can settle on the array, so teams are allowed to clean it with deionized water.

  • External irradiance is not allowed, so teams need to ensure that nothing nearby reflects light toward the array, including mirrors or white blankets, etc.

• Energy Storage

  • SOVs have a weight limit for their battery packs, but this does not apply to MOVs.

  • Supplemental batteries are permitted to power critical systems before the main battery is connected, or during a BPS fault.

  • Supplemental batteries are also permitted to power safety features, including the horn and driver ventilation fans.

• Battery Protection Systems

  • Active protection automatically disconnects the battery cells when safe limits are exceeded. This type of protection is required for secondary lithium-ion cells.

  • Passive protection displays the cell measurements to the driver, and the driver is responsible for deciding when to stop using the battery.

• Battery Enclosure

  • Must be at least 1 MΩ of resistance to ensure the battery pack is isolated in the event of a fault.

  • Must be labeled with warnings in at least a 10 mm font.

  • Requires forced ventilation that exhausts to the exterior of the vehicle.

  • Must be able to be secured so that the modules and cells cannot be accessed during the race.

• Main Fuse

  • Must be properly rated to isolate the maximum DC voltage and mechanically constrained.

  • The current limit must be less than 200% of the maximum expected currents and less than 75% of the wire capacity to prevent melting the wires.

  • Must be a fast-acting fuse to prevent damage as soon as possible.

  • Any other connections to the battery pack must be fused or current limited.

• All cables need to be sized for the expected system currents.

• Power switch

  • Must be controlled by the driver and the BMS.

  • Must be properly rated to isolate the maximum DC voltage and mechanically constrained.

  • Must be 2 BPS fault indicators that blink during a BPS fault; one on the top of the car and one on the dashboard.

  • There must be 2 kill switches; one on the outside of the vehicle and a 20 mm in diameter, red push button inside the car.

• Control

  • The driver must have sole control of the vehicle.

  • The accelerator pedal must return to the 0 position if released, must be accessed by the right foot, and it must be on the right side of the brake pedal.

  • The cruise control can only be activated by the driver and must automatically deactivate when the brake is pressed or the car is off.

• Shock hazards

  • Any voltage > 32 V is considered high voltage and must be protected to prevent inadvertent human contact.

  • High voltage systems must be labeled with 10 mm font.

  • Carbon fiber is conductive, so it must be isolated from the electrical systems.

  • Covers to all enclosures must be firmly secured.

• MOV Charging and Metering

  • Required to have a J1772 compliant onboard vehicle charger. This converts 120-240 Vac to a current limited DC voltage to charge the battery pack.

  • The charger must be secured and waterproof.

  • All high voltage AC and DC voltages must be isolated from each other and the chassis.

  • Required to put a charging meter (provided by ASC) between the charging adapter and the charger to measure how much non-solar energy we use during the race, which is used to calculate our score.

  • During charging, the BPS must be enabled and the vehicle must be stationary.

  • The charger must be labeled as high voltage.

  • Teams are allowed to charge the car using a generator.

  • The battery box must be sealed so that the only energy comes from the charger or the solar array.

Solar Car Body

• The L x W x H of the car must be less than or equal to 5 x 2.2 x 1.6 m.

• Only dynamic components can shift.

• There must be a minimum of 50 mm clearance between the car body and the ground.

• Lighting

  • The lights must be at least as bright as a reference light seen from 30 m away.

  • The lights must be visible from specific angles and positions (see the regs for complete list).

  • We must have DRLs, front/side/rear turn indicators, rear and center brake lights, and a BPS fault strobe light.

• Visibility

  • The driver’s eye height must be 70 cm from the ground.

  • The windshield must have a rain clearing mechanism (usually just a hydrophobic coating).

  • There must be a rear vision system (mirrors increase aerodynamic drag, so we use cameras).

• The driver and passengers must have air circulation (can be augmented by fans).

• Egress

  • All drivers and passengers must be able to get out using their nearest exit in 10 s.

  • All drivers and passengers must be able to get out using a different exit that is at least 90 degrees away from the nearest exit in 15 s.

• Each occupant must have a ballast box. The mass of each occupant and its ballast must be at least 80 kg.

• The vehicle must carry a data logger given to us by ASC that tracks vehicle location and speed.

• Each solar car must have the following markings

  • Team number

  • Institution and sponsors

  • Event logo

  • National flag

  • Front signage

• Mechanical - High Level

  • Body panels must be secured to prevent unintended movement.

  • All moving parts must be covered.

  • The solar array must be attached by two independent and different methods.

  • The vehicle needs to have 4 wheels, arranged symmetrically, and the distance between the back wheels and front wheels needs to be greater than half the width of the car.

  • Tires must be compliant with US DOT standards or equivalent and the manufacturer’s ratings/specifications must be followed.

  • The cockpit must be designed to protect occupants from injury.

  • Fasteners must be suitable type, strength, and durability.

  • Brakes must meet specs and account for possible failures.

  • The parking brake cannot be a tire/wheel contact style brake.

  • The steering wheel must be strong enough to withstand loads applied by the driver (not 3D printed), there must be steering stops to prevent dangerous or damaging steering travel, and the car must be able to make a U-turn within a 16 m wide lane.

  • The car requires a hardpoint where a rope or strap can be attached to tow the car for emergency recovery purposes.

• Dynamic Stability

  • The car must be able to

    • drive in a figure 8 in less than 9 seconds per side.

    • stay within a 3.5 m lane for at least 250 m, regardless of crosswinds or gusting conditions, at 104.6 km/h (65 m). If this cannot be done, the car’s speed will be limited to the maximum speed that allows the car to pass this test for the entire event.

    • pass a slalom test at 11.5 seconds

    • stop with an average deceleration of 4.72 m/s² when driving at 50 km/h or greater.

• Occupant Requirements

  • Minimum of 2 drivers, maximum of 4 drivers.

  • Maximum of 8 passengers.

  • The weight of each occupant and their ballast is at least 80 kg.

  • Each occupant must wear a helmet while operating the solar car. The helmet must meet international motorcycle standards and will be inspected during Scrutineering.

  • Occupants must wear shoes.

  • Occupants must spend less than 6 hours per day in the car.

  • The occupants must stay hydrated (must have at least 1 L of water each must be provided).

  • Communication with the driver must be verbal and hands-free at all times.

  • Cell phone use must comply with local laws.

  • The driver must be in communication with the solar car caravan.