Elec <> Strategy

Notes from strategy sync, 6/26
Overall goal: make telemetry as simple as possible

Comms:

• Wifi

  • Low range, especially with ESP32 (30m? have we tested it? we will be outside where there are no walls etc.)

  • High data rate (multiple MBps)

  • Lost packets are resent, no missing data (unless connection completely drops)

• RF

  • Very long range (1km?)

  • Can interface directly with Arduino with minimal code

  • Arduino supports CAN, reads bus, stores in json and sends as bytes to the transmitted

  • Another Arduino receives the messages on the chase car, sends it to computer over serial

  • Make sure antenna is omnidirectional

  • Loses packets

• leaning towards RF due to range advantage, need to implement systems to account for data loss

  • Add checksum to verify integrity, and just interpolate if data is bad?

  • How will the receiver know if a byte was missed completely? @Mitchell Ostler

  • Maybe we can add a rolling counter?

  • Can we implement our own retransmission thing where if checksum doesn't match or counter is not sequential byte gets resent

  • Receiver can send ack to signify successful reception

  • If data transmission can't be guaranteed, coulomb counting has to be done on the car itself

• To look into exactly what hardware to use @Mitchell Ostler

Project Responsibility:

• Largely a strategy owned project, with fw/hw support

• FW

  • Provide background information

  • Define system requirements, including packet format

  • Assist in hw setup

• Strategy

  • HW purchases

  • System implementation

  • Integration with database and models

  • Testing and validation

Timelining:

• Likely to start more seriously in the fall

  • Currently lacking onsite members capable of independently taking this on

  • Can be alleviated by providing detailed system requirements and resources

• FW to assign someone on-site to support

Elec Data Points:

• Primarily interested in battery metrics

  • State of charge (SOC)

  • Power usage

  • Power generation

• Overall health of systems (whether they are online or not)

• Everything that occurs on the CAN bus will be broadcasted over telemetry

Telemetry Power

• Will be powered off aux batt, need only to supply 5v

• Aux batt can be recharged/swapped without penalty at least once a day

  • Maybe more often with penalty? Don't know, @Yanshen Zhou can you take a look?

Strategy General Update:

• Building out their microservices

  • Correct me if I'm wrong but the goal is to process a bunch of data to feed into a live loop decision model

• This lets us determine if our car has enough energy to take optional loops, increasing our distance travelled (race is distance based not time)

  • Largely developing models for external facing data

  • Weather API integration

  • Route elevation

  • Solar irradiance

• Primarily missing internal metrics due to lack of system definition

  • How SOC plays into the model

  • Correlating solar irradiance with power generation

    • Using datasheet?

  • Power budget and typical vehicle consumption

    • Previous power budget https://github.com/uw-midsun/strategy/tree/master/auxloss

    • @Forest Zhou to work on this

• To look into range sensitivities for mass and non-motive power consumption @Rodrigo Tiscareno