- Thu Sep 23, 2021 1:49 pm
#53226
You can apply incremental steps in sensor heating, from no control (immediate heating to full temp on power-up), to a timer delay either in the vehicle or the controller, to heat on after start signal, to RPM sensing, e.g., 8Hz/500rpm before heating, to one OEM-style with an exhaust thermocouple that triggers full warmup above condensation temperature.
Additional parameters might be for other cold-shock conditions such as spark-cut rev-limiting, or conversely a bypass for hot sensor start-up tuning.
If you look at the sensor datasheets, you'll see a ramped warm-up profile, where it immediately begins low-current PWM heating on power-up in order to prevent damage, and follows with 100% PWM to full temp by time or temperature. Your decision is for what level of heating control to apply, based on your actual conditions and needs, and the trigger (if any) for each control step (if any). How deep do you need to go?
Remember, the control theories were to strive for long life in your Mom's car. In performance and racing we abuse them consistently for other purposes, where the sensors are regarded as consumables, similar to spark plugs and oil filters.
Additional parameters might be for other cold-shock conditions such as spark-cut rev-limiting, or conversely a bypass for hot sensor start-up tuning.
If you look at the sensor datasheets, you'll see a ramped warm-up profile, where it immediately begins low-current PWM heating on power-up in order to prevent damage, and follows with 100% PWM to full temp by time or temperature. Your decision is for what level of heating control to apply, based on your actual conditions and needs, and the trigger (if any) for each control step (if any). How deep do you need to go?
Remember, the control theories were to strive for long life in your Mom's car. In performance and racing we abuse them consistently for other purposes, where the sensors are regarded as consumables, similar to spark plugs and oil filters.
-= If it was easy, everyone would do it =-