It seems like the R4EV (as well as a Highlander Hybrid I used to own) goes out of its way to copy the "idling" behavior of an automatic gas vehicle. Basically at under 3mph when take your foot off the gas, power "trickles" to the motor causing a ~ 1mph/s acceleration. Likewise over 3mph, when you take your foot off the accelerator, the regeneration system kicks in and power "trickles" back to the battery causing a ~-1mph/s deceleration. Shifting to "B" increases the deceleration to what I am guessing is the maximum (?) capacity of the regen system. (I don't think "B" does anything else.)
My point is that this "dumb" legacy behavior takes no consideration of the current grade, either uphill or downhill.
An EV system has potential for so much more. Why an EV should have to creep forward (or backward if your on an uphill slope) is confounding.
What I propose as a better behavior is basically this:
v - current velocity
v_idle - idle target velocity (+/- hysteresis) - make this a user preference from 0-4 mph
Releasing brake at stop (0<=v<v_idle)
accelerate at a_rest, where a_rest is a user preference from 0-2 mhp/s
Coasting (v_idle < v)
decelerate at a_coast, where a_coast is a user preference from -3-0.mph/s
AND follow these equations REGARDLESS of incline. Imagine not drifting backward when stopped on steep inclines, or not having to shift to "B" or "ride" the brake (and wondering whether you were still in the regen envelope or wearing the pads).
Also I not sure what the purpose of shifting to neutral is in an EV, but it would simply set a_rest=0, likewise in this proposal the purpose of "B" become moot?
My point is that this "dumb" legacy behavior takes no consideration of the current grade, either uphill or downhill.
An EV system has potential for so much more. Why an EV should have to creep forward (or backward if your on an uphill slope) is confounding.
What I propose as a better behavior is basically this:
v - current velocity
v_idle - idle target velocity (+/- hysteresis) - make this a user preference from 0-4 mph
Releasing brake at stop (0<=v<v_idle)
accelerate at a_rest, where a_rest is a user preference from 0-2 mhp/s
Coasting (v_idle < v)
decelerate at a_coast, where a_coast is a user preference from -3-0.mph/s
AND follow these equations REGARDLESS of incline. Imagine not drifting backward when stopped on steep inclines, or not having to shift to "B" or "ride" the brake (and wondering whether you were still in the regen envelope or wearing the pads).
Also I not sure what the purpose of shifting to neutral is in an EV, but it would simply set a_rest=0, likewise in this proposal the purpose of "B" become moot?