AutomaticGearbox

The automatic gear box (device name "automaticGearbox") is a model of an automatic transmission including a one way hill holding viscous clutch, and a parking lock. Unlike a manual gearbox, the auto shifts smoothly between gears. In a Powertrain it is designed to be placed behind a viscousClutch or torqueConverter only, and should have a shaft, differential, rangeBox or splitShaft connected to it.

Jbeam Properties

Name	Type	Optional	Default Value	Description
gearRatios	array	false	na	This array is the list of gear ratios available to the gearbox. 0 represents neutral. A negative number indicates a reverse gear. The gearbox will have as many gears as specified in the array. Ex "gearRatios":[-3,-2,0,4,3,2,1,0.5] has 5 forward and 2 reverse gear ratios.
oneWayViscousCoef	number	true	5	This value controls how stiff the hill holding viscous clutch is. A higher value will make the vehicle less likely to creep backwards on a hill.
oneWayViscousTorque	number	true	=onewayViscousCoef*20	The upper limit for hill holding torque, used for stability reasons.
parkLockTorque	number	true	1000	The upper limit for the parking lock torque. If exceeded, the parking lock will slip.
parkLockSpring	number	true	Auto calculated	The stiffness of the parking lock spring. Too high may cause instability.
friction	number	true	0	The friction torque applied to the input side of the gearbox.
shiftEfficiency	number	true	0.5	The max proportion of torque loss during the shift.
gearChangeTime	number	true	0.5	The time taken to smoothly shift from one gear to the next.

Examples

Here is an example of the required powertrain section, along with the additional section for the properties.

    "powertrain": [
        ["type", "name", "inputName", "inputIndex"],
        ["automaticGearbox", "gearbox", "torqueConverter", 1],
    ],
    "gearbox": {
        "gearRatios":[-2.27, 0, 2.79, 1.54, 1.00, 0.695]
        "parkLockTorque":2000,
        "oneWayViscousCoef":8,
        "friction": 1,
    },