Notes on DataAcq Presentation

Ishan's Notes

Race Strategy
Sensors
Data used for analysis
New peripheral board

Current:
- IMU (could be used actively in conjunction with motor control?)
- Airflow
- Temperature
- Tire Pressure (could be used for motor control?)

New Sensors
- Brake Pedal (why marked as new?)
 - Should probably be under controls domain
- Steering sensor (useful for two wheel drive software differential)
- Atmo Pressure Sensor
- Humidity Sensor

Telemetry
- Regenerative Braking message over CAN (wouldn't this be encoded within the motor messages?) (what type of data do you want to see)

Dashboard (chase car)
- Not relevant to controls

Race Strategy
- Optimize track stuff
- Will be relevant to controls after this race, to integrate data acq race strategy stuff
- Monitors efficiency of the car
- Every 3 secs, outputs an optimal speed for the vehicle over CarCAN
- Could be integrated into display w/ driver notifications

Maddie's Notes

- Adding brake pedal sensor because they want angle and we're just a button

Notes on Array Presentation

Ishan's Notes

- Power Electronics to track max power point to get most power out of array
- Bigger cells
- Make MISO and MOSI pins actually correct
- 1 RTD chip per 8 sensors with a decoder (with a select pin)

Maddie's Notes

Power Gen:

Make car go

• Buy cells and do stuff
• Design power electronics for mppt, boost voltage
• Regulations: only commercial silicon cells, max 4 m^2, only 6 types/sizes max

New things:

• Buy better cells, update MPPT to match, improve blackbody A
• Newer cells (Maxeon Gen 5 and 6) have doubled current so MPPT needs to be redesigned with bigger inductors and capacitors (1
• BlackbodyA tracks temp and irradiance in car. MISO and MOSI swapped so gonna fix that, simplify with MUX/decoder for RTD, fix shorted I2C wires to support >1 irradiance sensors
• Matthew is working on /has sims for ideal inductor capacitor size
• Irradiance sensors: something about there being global and local maxima and there are algorithms to find local maxima but the irradiance sensors tell you when to run to check for global maxima because we don't want to get stuck in a local one but global one takes time so we can't do it all the time,

Diya's Notes

solar array, 3 sub arrays. MPPT = Maximum Power Point Tracking 

How are the sims going to be designed? or are there sims out there that can replicate the behavior you are trying to achieve? A: Sim has already been designed. Sim tells us the specs we need. 

How many types of solar cells are being used? A:

What is an irradiance sensor?  A: The irradiance sensor tells the change in light. Black body supports two. IV curve. scan the global. This guides what would need to change to get max light.

Notes on Power Systems Presentation

Ishan's Notes

- Manufacture HV battery pack
- Improve Battery Pack Safety
- Faster Manufacturing
- Better Power Usage
- Improve charging efficiency between battery and array
- Has there been any noticeable improvements from characterizing each cell individually that would be lost from just taking samples from each box?
- From current characterization stuff, how much do the cells each actually differ in terms of characteristics?

Diya's Notes

Areas of improvement include stiff and hard to connect. Is there any advantage to having them paired up? A: no, we want them to be modular. when you say modules what is it. A: 9 cells. 

Cell manufacturing plant- similar characteristics. worried about the variability of every cell. A: However, it doesn't matter because they are close enough anyways. SOC, impedances, time stamps. It has been done with other solar cars. 

Fuse on each branch needs to be implemented. 

Maddie's Notes

Power systems

• Next gen goal: improve battery pack safety and reliability, accelerate battery manufacturing process, optimize power usage and reduce waste
• Main battery must power majority of systems
• Considering dual charging
• Battery: manufacturing was hard and doesn't work so well, so want better mode of connecting modules and organizing sensors. To many difficulties created in the name of modularity -> maybe reprioritize
• Cell manufacturing: sample instead of test everything single one
• Going to try to design a PCB to help them connect better
• Ignition switch redesigned
• Currently signals go through Controls ex to turn stuff on the signal just goes through Controls
• Q: Does characterizing each cell help much?
• So far curves look very similar and many teams just sample too
• Q: We need to have a fuse on each branch. Do we have a fuse on each branch?
• Working on it
• Going to use the same configuration next year but change connectors and manufacturing
• Need impedances of each module to be the same which is why in part they were trying to characterize every cell but they seemed very similar so they will probably be fine
• Modules are in parallel so impedances of each model doesn't really matter?

Notes on BPS Presentation

Ishan's Notes

Issues with current gen:
- Hardware uses non-standard and scarce chips
- Long wakeup time for isoSPI chips sampling

Goals:
- Standardize software drivers
- Transition to SOM
- New hardware to use common protocols
- How do you monitor the battery health now? Why is it a "nice to have" rather than "must have"?
 - Wanna know how damaged the cells are
 - We don't currently monitor the battery health
- Actively monitor isolation between frame and HV line (isolation is  required by regs, but active monitoring is not (clarify this))
- Switch to CAN from isoSPI
- Tachometer feedback from fans

Diya's Notes

BPS minions - 3 for the peripherals

voltage, temp, and current will still be sampled but using new hardware. 

Battery health is difficult to monitor, but it will tell us how damaged the battery is. 

Fault recovery --- going into a regular state instead of shutting off the entire car. 

BPS - doesn't need all evac for CAN stuff. Non CAN such as over temp --> kills car. 

recovery is for CAN stuff

Maddie's Notes

• Volt, temp, amperes board
• Uses Micrium RTOS, send CAN transmissions
• Next gen: maintain features but want to standardize hardware, drivers, communication protocols
• Desired improvements: active battery balancing, accurate state of charge, battery health, system fault recovery
• New features: isolation between frame and HV line (required by regs??), contactor weld detection on array contactor, switch from IsoSPI to CAN, tachometer feedback from fans (to know when fans are dead), bluetooth debugging
• Q: current battery health? Why just nice to have?
• Currently don't do anything, hard to do because requires measuring impedances, would tell you how damaged the cells are
• Q: how to implement active battery balancing and active state of charge?
• Not using cells to charge each other, more like passive battery balancing
• Characterizing system state through probability stuff, state estimation through IV cures, AC DC
• Q: on fault recovery:
• BPS currently shuts down for everything but doesn't need to.
• Something about contactors

Stuff that may need to be addressed in PDR

Ishan's Notes

- Figure out dist. sensor before PDR so Aeroshell can make cutouts depending on size
- Wire harnessing wants a small board that they have to route less wires to in the back of the car (LIN? CAN?)
- Icons for steering wheel? Coordinate with Ergo to figure out
- Ask Akshay what he was saying to Philip and Steven about Regen stuff

Questions from SRR Q&A

• Q: How do we blind spot monitoring?
  • Distance sensor on sides
• Q: On blind spot: add something more to notify faster and more imperative?
• Q: Also steering wheel is getting very complicated
• Q: Separate display that all systems can input to that is its own device on CAN instead of going through Controls?
• Q: What is the justification for putting two-wheel drive on Controls' requirements review (sort of is this all in your system's jurisdiction)
• Q: on display options?
• Q: Where are we placing blind spot tracking?
  • Sides (would have to make cutout for that)
• Q: How does the new one pedal mode help?
  • Most cars implement the new way so it will be more intuitive
• Q: Any plans to change current backup camera?
  • No current plans to change that. Considered adding it to the display but the driver needs to see it at all times anyways
• Q: On coasting with one pedal mode
• Q: What does pedal input match to:
  • Current, but velocity in one-pedal mode
• Q: Amount of switches?
  • GPIO extender (which goes on the SOM)
• Q: Still planning to use dashboard as simboard?
  • Maybe not could be annoying
• Q: fan potentiometer -> scroll wheel on steering wheel?
  • Perhaps, but maybe don't want it changed too easily