Goals: Finalize sensors used and get a space claim of available space spacing for boards and wiring. Discuss unsprung related faults & data display on dash.

Unsprung:

• Hall effect per wheel (2)

  • entails one board per upright and one magnet per hub

    • multiple magnets needed perhaps bc we cant mount the magnet in the axle itself

  • usage: lets us check the speed of the front two wheels vs the rear for speed. also lets us check for toe, if the speeds are significantly different then we can adjust toe to make them the same speed (ish)

  • new member project: measuring toe

  • would make sure our toe is good beforehand and then collect data

  • confounding variables to consider → differences in tire

  • more magnets would give more accurate reading is the idea

    • is the sweet spot 2 or a different number?

      • will need to figure out a reason for the # of magnets chosen

      • how to secure magnet to the wheel hub

      • EV just epoxied to their center lock; they machined slots into their centerlock for the magnets

      • Electrical: will talk about best # of sensors

      • Dynamics: will talk best way to mount; either include in our manufacturing plan or epoxy onto hub

• Actual Dynamics BoardarchivedPreview ← link to current dynamics IMU board with idea of how hall effect sensors would be mounted on wheel hub/unsprung assembly

• in-line brake pressure sensors (2)

  • one pressure sensor per banjo-bolt connection

  • would be on the calipers on themselves

  • usage: lets us check for brake failure real-time, also to check pressure within system and tune brake bias

  • what about knowing pressure loss over length in brake lines thru 2 sensors?

    • could look into more into it; might be more useful than comparing left to right

    • originally this was the plan → was integrated into pedal board originally

    • would let us know if there is a brake line leaking if there is a significant pressure difference

    • can check in code the brake pressure and display an error; can check pedal displacement vs how much you are actually braking to see if something is wrong

    • 1st purpose for sensor: to see if brake line leaking

      • though can eyeball this technically and the driver can feel the difference

    • 2nd purpose for sensor: would help determine if we are getting the brake bias we want and adjust from there

      • Dynamics too look into/double check if our understanding of how to adjust brake bias is correct

    • 2 sensors total: one on one of the front wheel; one on the back wheel

      • don’t need one on each front wheel b/c if one changes pressure in the front then the other front one will also change

      • the sensor has to be part of the brake lining itself; will be part of the caliper itself

• IMU on each upright / tarm and the frame (4)

  • usage: imu’s on upright let us see the real bump forces that unsprung experiences whereas one on frame lets us see bump force on frame, can prolly work out like some suspension/shock stuff from differences in forces from wheels to frame

  • see the way the inner vs outer wheels angle changes when turning to evaluate ackerman

  • would be a main thing to do evaluate our sus and mostly for next next gen

  • frame one would be validating sus kinematics

  • IMU on the frame to help see this; yaw and roll rate; can then adjust sus characteristics to get closer to our goal kinematics

  • IMU would allow to see acceleration in x,y,z directions

  • current dynamics board also includes gyroscope so IMU on frame would work

    • IMU for the car itself

    • would help to determine what slope/angle the car is on

    • could be on the bellypan/frame itself

    • can help us tell what incline we are on and see how we can optimize

    • know what current max incline the car can get over; would be a next next gen thing to optimize and get over a steeper incline ---> could make a FBD

    • this IMU can be the same as above described IMU (the one that would help us with roll,yaw, and spring rates)

    • 3 on wheels (2 upright; 1 on trailing arm); 1 on frame/bellypan

    • this sensor would help us with pose of the car

      • this could be very useful for knowing where you are at physically → for helping know stuff on the electrical side

      • IMU on the frame would help us determine forces on the frame itself vs bump force at the wheels

      • could also help us determine ride/natural frequency of the frame

      • wheels move independently of the frame hence reason for wanting an additional IMU on the frame

• real-time wheel pressure (3) AND temp sensor (3)

  • screws into valves for rims

  • usage: lets us check for flats and ensures we are operating within pressures

  • Would these be wireless? Otherwise, it could get interesting.

    • HAS to be wireless basically

  • right now have wireless wheel pressure sensors

    • need to check the current model selected doesn’t interfere with unsprung assembly

    • model might not exist but data sheet and in person exist

    • current TPMS sensor doesn’t have proof of concept yet so this could change

    • temp sensor helps us find where our contact patch is + could help us determine ideal steering characteristics

      • could do a temp camera on drive days

      • multiple temp sensors on wheel would be hard on the electrical side

        • this can be lower priority sensor for now