3/16/2022 - Rover Overview

Owned by Farris Matar
Last updated: Apr 16, 2022 by Logan Hartford
3 min read

Member

Main Project

Update

Action Items

Member

Main Project

Update

Action Items

@Ari Wasch

BMS

  • Went through reviews, should be finished tonight

  • Prepare ideas for the new designs/revisions brainstorm next week

@Chealsie Bains (Deactivated)

Jetson Carrier

  • Update on Jetson Carrier layout & stackup?

  • Prepare ideas for the new designs/revisions brainstorm next week

@Farris Matar

PDB/BMS

  • 80% through unit 3 of PDB + BMS, no shorts so far

  • Finalizing new electrical leads

  • Acquire crimped wires & missing RS422 parts to complete assemblies & connectors

  • Finish PDB + BMS unit 3 assembly

  • Documentation for PDB Rev. 3

  • Prepare ideas for the new designs/revisions brainstorm next week

@Ivan Lim

Science

  • Found replacements for most components out of stock

  • Prepare ideas for the new designs/revisions brainstorm next week

  • find replacement can bus ic/molex connector

@Jason Gao

RS422

BLDC motor controller

  • RS422 - unable to crimp connectors due to vision and size.

    • Will likely buy precrimped wires

  • Prepare ideas for the new designs/revisions brainstorm next week

  • BLDC Layout

  • RS422 testing once harness made

@Logan Hartford

Multiphase buck converter

  • Finished soldering boards

  • Complete unpowered and powered tests

  • Start working on performance testing

  • Did line regulation then just worked on a document for explaining and collecting other performance parameters.

  • Prepare ideas for the new designs/revisions brainstorm next week

  • Going to finish my testing document

  • Won’t be able to go to the bay this weekend, have to drive home to help my mom

  • What equipment should be used to test load regulation?

  • Is there a a better multimeter to test line regulation with than the little handheld one?

@Taylor Mcnabb

SPI LVDS

  • SPI Host Board is on its way

  • Need to select replacement for SPI peripheral IC

  • Layout 30% done

  • Prepare ideas for the new designs/revisions brainstorm next week

  • Continue layout

  • Select IC

@Wolfgang Windholtz (Deactivated)

Science

 

  • Prepare ideas for the new designs/revisions brainstorm next week

2021-2023 Rover Overview

Power

  • 12s LiPo (12 cell Lithium Polymer battery) powers the entire rover at 48V nominal voltage

  • PDB + BMS (Power Distribution Board + Battery Management System) regulates the battery power at lower voltages to power the Jetson AGX with 17V and Science & other small boards with 5V

    • BMS measures battery voltage and state of charge, and handles cell balancing (ensuring all cells are at equal voltage)

  • 48V-24V multi-phase buck regulates battery power to 24V at high current to power the Arm subsystem, Science motors, and communications (ethernet switch & antennas)

  • Unregulated battery power goes straight to the Drivetrain subsystem to power the motors

Arm

  • 8 motors controlled by Odrives

  • Encoders on all motors for monitoring position

  • 24V power from PDB

  • Arm interacts with objects to complete missions in the competition - requires precision & power

    • Needs to lift a 5kg weight

    • Use an Allen key to use on a screw

    • Type on a keyboard

  • Uses SPI (communication protocol) for communication with encoders

Drivetrain

  • 6 wheels, 3 on each side, using 6 brushless DC motors controlled by Odrives

  • Motor encoders used for monitoring and controlling movement

    • Encoders communicate using RS422 communication protocol

  • Currently Odrives are used as motor controllers. However, a prototype custom brushless DC motor controller is in development to provide a more tailored fit to the rover’s design and needs than the Odrives

Science

 

Main purpose: complete the science challenge

  • Scoop dirt, mix it with chemicals in a test tube, analyze for signs of life

  • Use brushed DC motors instead of brushless

  • Science board handles the encoder, sensor, motor, and communication connections

  • Uses a GPIO expander to get more GPIO control pins, communicates with I2C

  • Spinning mechanism to mix tubes is powered by drivetrain

  • 3 USB cameras to visually analyze the soil as well (not controlled by science)