throttle hysteresis
04-23-2010, 10:37 PM
#2
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Usually it means multiple parameters must be meant for an action to take place.
EX: For Deceleration Fuel Cut-off (DFCO).. to occur..
All the following parameters must be met: Vehicle Speed, Coolant Temperature, Manifold Pressure (MAP), and RPM. From EFILive: When all of the DFCO enablers are met, hitting any DFCO activate level will turn on DFCO. After DFCO has been enabled hitting any DFCO disabler or hitting every DFCO deactivate will turn off DFCO.
Thats about the simplest explanation I can give. You have to just kinda think about it, and let it sink in.
Hope that helps..
EX: For Deceleration Fuel Cut-off (DFCO).. to occur..
All the following parameters must be met: Vehicle Speed, Coolant Temperature, Manifold Pressure (MAP), and RPM. From EFILive: When all of the DFCO enablers are met, hitting any DFCO activate level will turn on DFCO. After DFCO has been enabled hitting any DFCO disabler or hitting every DFCO deactivate will turn off DFCO.
Thats about the simplest explanation I can give. You have to just kinda think about it, and let it sink in.
Hope that helps..
04-28-2010, 08:43 AM
#3
In control software hysterisis is normally an offset used to eliminate controller or output chatter.
A couple examples:
Your rev limiter is enacted at 6200 rpm. At 6200 rpm the the ignition is shutoff. At 6100 the ignition is turned back on. The hysterisis for your rev limiter is 100 rpm.
Your speed limiter it is enacted at 160 mph. At 160 mph your limiter kicks in, at 158 mph the limiter is eliminated. The hysterisis is 2 mph.
A real basic example is your house thermostat. Your heater turns on at 68 deg F and turns off at 71 deg F (hysterisis of 3 deg) Your heater is set up this way because if it had only one signal to turn on at 68 deg F your heater would be freaking out incessively switching on and off as your house temperature oscillated around 68 deg F.
The same 'freaking out' happens in controllers/computers, but at a much higher rate. It can be bad for controller loading and is bad for digital and analog outputs..... Or sometimes a hysterisis is necessary to get the desired result from the process.
So, throttle hysterisis is most likely your throttle turning or activating something at X position, and turning it off at y position. The software will sometimes give you both X and Y or sometimes it will just give you X and the hysterisis.
A couple examples:
Your rev limiter is enacted at 6200 rpm. At 6200 rpm the the ignition is shutoff. At 6100 the ignition is turned back on. The hysterisis for your rev limiter is 100 rpm.
Your speed limiter it is enacted at 160 mph. At 160 mph your limiter kicks in, at 158 mph the limiter is eliminated. The hysterisis is 2 mph.
A real basic example is your house thermostat. Your heater turns on at 68 deg F and turns off at 71 deg F (hysterisis of 3 deg) Your heater is set up this way because if it had only one signal to turn on at 68 deg F your heater would be freaking out incessively switching on and off as your house temperature oscillated around 68 deg F.
The same 'freaking out' happens in controllers/computers, but at a much higher rate. It can be bad for controller loading and is bad for digital and analog outputs..... Or sometimes a hysterisis is necessary to get the desired result from the process.
So, throttle hysterisis is most likely your throttle turning or activating something at X position, and turning it off at y position. The software will sometimes give you both X and Y or sometimes it will just give you X and the hysterisis.
Last edited by NoGo; 04-28-2010 at 08:52 AM.
