Changes for page Sensor Module
Last modified by Heimir Thordarson on 2026/07/05 12:56
From version 64.8
edited by Heimir Thordarson
on 2026/03/23 19:39
on 2026/03/23 19:39
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To version 67.6
edited by Heimir Thordarson
on 2026/07/05 12:56
on 2026/07/05 12:56
Change comment:
There is no comment for this version
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... ... @@ -259,7 +259,7 @@ 259 259 ((( 260 260 {{mathjax}} 261 261 $$ 262 - T= \frac{1}{\frac{1}{T_0} +\frac{1}{\beta}\ln\left(\frac{R_T}{R_0}\right)}262 +Q = C_D \cdot A_D \sqrt{\frac{2 \cdot \Delta P}{\rho}} 263 263 $$ 264 264 {{/mathjax}} 265 265 ))) ... ... @@ -267,15 +267,36 @@ 267 267 268 268 where: 269 269 270 -* {{mathjax}}\(\ beta\){{/mathjax}}=materialconstantthatdefinesthesteepness of its resistance-temperature curve between two temperaturepoints,usually 25/85 degrees celsius. In thiscaseit is 3976 //**K.**//271 -* {{mathjax}}\( T_0\){{/mathjax}}=The test temperature at whichthe thermistor is10k {{mathjax}}\(\Omega\){{/mathjax}}, which in this caseis 25 degreescelsius.272 -* {{mathjax}}\( R_0\){{/mathjax}}=Theresistanceofthethermistorwhenitis25 degreescelsius.273 -* {{mathjax}}\( R_T\){{/mathjax}}=Thelive resistanceof thethermistor.270 +* {{mathjax}}\(Q\){{/mathjax}}= Waterflow through the equivalent orifice 271 +* {{mathjax}}\(C_D \cdot A_D\){{/mathjax}}= practical cross section of the orifice 272 +* {{mathjax}}\(\Delta P\){{/mathjax}}= Pressure difference between the two pressure sensors 273 +* {{mathjax}}\(\rho\){{/mathjax}}= Density of the cooling liquid 274 274 275 +The sensor used on the AR26 car is the [[Bosch Motorsport PST-F 1>>https://www.bosch-motorsport.de/content/downloads/Raceparts/Resources/pdf/Data%20Sheet_70496907_Pressure_Sensor_Combined_PST-F_1.pdf]] and has the following transfer function for the output voltages based on pressure and temperature. 275 275 277 +=== Pressure sensor === 276 276 279 +The pressure sensor build into the PST-F 1 has an supply voltage of 5 volts and has a output voltage range of 0.5 to 4.5 volts. The following formula shows the pressure based on the output voltage. 277 277 281 +{{mathjax}} 282 +$$ 283 +P = 2.5 \cdot V - \frac{5}{4} 284 +$$ 285 +{{/mathjax}} 278 278 287 +Where: 288 + 289 +* {{mathjax}}\(P\){{/mathjax}} = Pressure from pressure sensor [bar] 290 +* {{mathjax}}\(V\){{/mathjax}} = Voltage output from the pressure sensor [volts] 291 + 292 + 293 + 294 += Alternative Usecases = 295 + 296 +For the AR26 sensor module, it proved itself being useful in taking extra task if any other systems stopped working. During the Vehicel Status Video (VSV) was the sensor module used as the Vehicle Control Unit (VCU), but did not measure all of the sensors which the original VCU was intended to measure. Considering that the suspension displacent and Acceleratior Pedal Position Sensors (APPS) are both potentiometers, can these be connected the same way so that the sensor module can measure the APPS. The sensor module is also designed to measure four pressure sensors for the cooling system which work on 5V, which luckily enough is also what the brake pressure sensors are running on. This means that the sensor module can measure the brake pressure by connecting them simularly to the module as the cooling pressure. 297 + 298 +The sensor module on the other hand is not designed to measure an extra 3 potentiometers which the VCU does. These sensor are the front suspension displacement sensors and the steering angle sensor. The sensor module can measure to an additional 5 potentiometers with some small changes on the PCB. This is done by using the thermistor inputs, removing the pull-up resistors, and supplying the sensor with 3.3V by conning one of the available pins on the main connector to 3.3V. On the main connector, is that pin number 33 to 42. If the pull-up resistor is not removed will the voltage input into the microcontroller become unlinear and unnecessarily difficult to calculate the length of the potentiometer. 299 + 279 279 = Bill of Materials = 280 280 281 281 == Circuit Board ==