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eSBR non-linear throttle response at low speed

Discussion in 'Troubleshooting: Bugs, Questions and Support' started by default0.0player, May 6, 2019.

  1. default0.0player

    default0.0player
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    At low speed 10% throttle is WAY more than 10% torque, making low speed handling very twitchy. At nearly stationary, 2% throttle is nearly 80% torque.



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  2. SebastianJDM

    SebastianJDM
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    strange, maybe because lots of load (especially on a hill like in the photos) will draw more current if not supplied with a sufficient amount of voltage from the throttle? not sure how well beam simulates that but it's the only explanation i can think of
     
  3. default0.0player

    default0.0player
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    The explanation of sensitive throttle is that the "engine load" calculation is still ICE-ish.

    Gasoline engines use throttle to limit air intake. If the RPM is very high, partially opened throttle will cause a big choke to the engine, reducing power(relative to full throttle) significantly. At near redline, 50% throttle is about 50% power. At low RPM the airflow is low so 20% throttle will not create 80% vacuum, thus 20% throttle makes engine output much more than 20% power at this RPM. At 0 RPM, the manifold pressure is always 1atm regardless of throttle position. However in an ICE at low RPM the max torque is also not high so most driver ignores the non-linear behavior.

    This can explain the eSBR torque output is more than 2% at 2% throttle is although the torque curve is electric, the throttle response is still use intake vaccum calculation.
     
  4. SebastianJDM

    SebastianJDM
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    interesting and good to know. hopefully that will be changed, along with some proper thermals for electrical components.
     
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  5. Arcanox

    Arcanox
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    Yeah, I definitely noticed it was very difficult to control the electric motors on the eSBR. It was the same on previous versions in user-made electric vehicles that utilized the "electricMotor" drivetrain component. In a real electric car, the throttle is typically mapped to "requested torque" with an optional non-linear map (such as for a "sport mode"). This way you can put your foot on the accelerator and leave it in one place, and feel a very consistent amount of torque applied until the motors reach their RPM limits.

    I use this method in the latest (not yet released) version of my hybrid system so that the "total output torque" is consistent with the pedal input, even when switching between electric and gas operating modes.
     
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  6. SebastianJDM

    SebastianJDM
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    will you be updating your hybrid system to use an electric motor as a separate powertrain component (a secondary power input), or keep all of the cool lua coding you did to integrate it into the transmission or whatever.
     
  7. Arcanox

    Arcanox
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    The electric motor already existed in previous versions of the game, but it's not accurate or versatile enough to use in the hybrid system. It's easier to keep the custom Lua code I've developed.
     
    • Informative Informative x 2
  8. default0.0player

    default0.0player
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    I am kind of think the pre 0.15 electric mod was actually a little bit more realistic. The eSBR electic efficiency is also calculated incorrectly. It's electric energy X 0.95 (electic efficiency)-friction(including dynamicfriction). In this way if you stall a motor and apply throttle, no electric is consumed because 0 mechanical energy is 0 electric consumption.
    Before 0.15 electic mods use motor→torqueconverter→cvt or automatic→drive shaft. This layout kinds of more realistic because the tachometer RPM is actually is the motor winding drive frequency and the torqueconverter output RPM is the rotor RPM, there's "slip".This simulates induction motor dynamics. The winding core loss is input*(1-electricefficiency), the friction loss is friction+dynamicfriction, and the squirrel cage resistive loss is the torqueconverter loss. And the higher the slip the more the torque and the less the effieiciency.
     
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