2024-26 Selected
add limit switch
front brakes are no useable
front link
dicre
Factor | Spec |
|---|---|
Mechanical Rating | Made of high quality ABS plastic and metal. Great durability, wear resistance, and strong connectivity. Each product is strictly inspected before leaving the factory to provide high-quality auto replacement parts. - Amazon |
Accuracy | IDK |
Type | TPS sensor, Flange Mount |
Output | Analog (ADC) |
Size | small  |
Factor | Spec |
|---|---|
Mechanical Rating | 1000 PSI 3/8-24 connection |
Accuracy | 400 KHz - natural frequency |
Type | 4-20mA Current Loop Transmitter |
Output | 4-20mA
|
Size | 24.5 Grams (Max.) Excluding Cable 2 wires, 36" = 3'
|
Daybreak 2025
Accel: https://p3america.com/slpc-series/
In the 2024-2026 car, Controls will need to detect the position of the accel pedal for movement, as well as the position of the brake pedal for fault conditions and telemetry. While the position of the acceleration pedal is necessary, the position of the brake is technically optional- all Controls needs is to enable the brake lights. However, for the purpose of analysis and additional features, we want to measure the position of the brake pedal and the pressure in the brake fluid line to
Send measurements to Data Aq for analysis
Detect and display a fault when there are discrepancies between the brake pedal position and brake fluid line
[ Possibly adjust the brake light brightness ]
The brake fluid will the comparable to the potentiometer used for calibration.
and these sensors will be under Controls since we require it for the car state and therefore would like to receive this data as fast as possible (in short, we need it more/sooner than Data Aq).
In the 2022-2024 cycle, we used a linear potentiometer for the accelerator pedal, and a button for the brake pedal (since entering brake state is a binary decision).
50mm Stroke (measuring length)
Cost: $144
SKU: SLPC 50 A 2K 1M (621400)
Compact linear displacement transducer with rod end bearings
2KΩ resistor value
18mm diameter (housing)
IP65 Rating
Connector: plug type w/mating connector included / Cable: 1 m length (3 wire)
Intended for industrial applications
IP (Ingress Protection) Environmental Rating: Standard for the resistance of the part to environmental conditions like dust and moisture.
How to read the rating:
IP[Protection from solid objects][Protection from liquids]
Protection from solid objects: 0 (none) - 6 (no ingress)
Protection from liquids: 0 (none) - 9 (high-pressure hot water from different angles)
“linear was a relatively arbitrary choice made by me bc it was the first one I found with a good mechanical rating” - Sid
Mechanical Rating
Accuracy
Type (angular potentiometers, brake line pressure sensor)
Output (ideally supports digital protocol we use)
Cost (to some extent)
Size
Name | Description | Type | Cost | Accuracy | Rating | Output | Size | Link |
|---|---|---|---|---|---|---|---|---|
SLP Linear Potentiometer | Used on Daybreak | |||||||
HoneywellMLH | $288 | |||||||
PST-360 Hall-Effect Through-Shaft Rotary Position Sensor | Rotary Probably do not full 360 degrees, get as small as possible | $60 | +- 1 degree | IP67, IP69K | SPI (best), CAN, PWM | 14mm and 17mm versions | https://www.piher.net/products/rotary-position-sensors/through_shaft/pst-360/ |
https://www.reddit.com/r/FSAE/comments/ab3gs3/brake_pressure_sensors/
Industrial wet pressure transducer from Mouser or Allied
Honeywell MLH200
pressure switch rated for hydraulics
https://www.aim-sportline.com/en/products/sensors/index.htm#pressuresensors
For brake pedal (not line): load cell to measure force
Digikey MSI, 0-1000ish psi
https://www.fsae.com/forums/showthread.php?12194-EV-Car-brake-pressure-sensor
Linear potentiometer may be cheaper?
Can call to see if company will give a discount
Radio volume potentiometers have been used with suspension measurements- cheaper but less precise
Ebay
https://fsaeparts.com/collections/for-the-car
https://www.hpacademy.com/forum/general-tuning-discussion/show/brake-pressure-sensors/
2000psi honeywell
https://www.apexspeed.com/forums/showthread.php?53094-Brake-Pressure-Sensor-Installation
On installation
“Banjo” bolts
https://www.reddit.com/r/FSAE/comments/5vvg3v/accelerator_pedal_position_sensor_apps/
Rotation angle using hall sensors
linear displacement
https://electronics.stackexchange.com/questions/173609/measuring-angle-position-of-a-pedal
Rotary potentiometer
https://en.wikipedia.org/wiki/Rotary_variable_differential_transformer
TI inductance-to-digital converters
https://www.fsae.com/forums/showthread.php?877-Pedal-and-sensor-assembly
Aiden’s Notes
Rotary Potentiometers
Easier to integrate (slides directly onto the pedal)
Make sure to get one with a measuring angle of similar size to the pedal rotation
Will require a bit more work on our end to convert “degrees” into a useful number for us to use
Waiting for Ergo to make decisions to proceed
Break Line Pressure Sensor
Most pressure sensors are pretty similar as far as I can tell besides threading and the amount of pressure they can handle
We are using 3/8-24” threading and 50-600psi
A potential option that other teams use
https://hhrperformance.com/i-31646738-aim-brake-pressure-sensor-dash-3-3-8-24-0-100-bar.html
I’m not confident that this will hold up over time
This is a more industrial option
https://www.mouser.com/ProductDetail/Kavlico/P265-1000G-F2A?qs=bZC7aUKSI5%2Fp83lG5BHXWw%3D%3D
With materials dedicated to standing up to brake fluid at high pressures over a long period of time
It also has better accuracy
$150
