If inertia and tire road adhesion could not "drive" the ICE/electric motive combination then there would be no need for the inertial sensor that is used to detect a rear-ender event and therefore instantly release the clutch to protect the electronics from over-voltage from a potentially "over-revved" traction motor.

GaryG:

I will be in FL in late January, Daytona and then over to Tampa. See TeamSeattle.com.

Conversation over StarBucks?

 

Sorry, I'm 29 years old. This maybe be true for my 75 years old grandma...

"You may have noticed that fewer and fewer FWD and front biased AWD vehicles now have manual transmissions. IMMHO that is because it is so horribly dangerous to downshift one of these on a slippery roadbed."

 

1) Because the slipping came after the wheel was turned and/or I hit my brakes. I'd pulled my foot off the gas long before that so engine braking should have already started my slide before I turned the wheels. You can definitely "feel" when wheels start to slip even when traveling straight and I've never felt them start to slip when I've downshifted or released the gas.

Not saying it can't happen..... I've never experienced it in 20 years.

 

The last I knew A+B+C = D

Engine drag was ALWAYS just waiting for the sum of the need for traction to exceed the actual traction.

It would undoubtedly be a much RARER incident were engine braking alone to result in loss of directional control.

But quite obviously it is something the Ford engineers were concerned about, fully expecting it would be implemented elsewhere, in applying for the patent

 

http://www.angelfire.com/biz/snwvlly/fwd.html

This article about sums up what I think about FWD vehicles on snow. It also points out that I've apparently been doing it for years becuase it just seemed to make sense--but without really knowing why. I'd never apply gas at a corner if I was slipping in my RWD car, but in my FWD it seemed pretty natural to me to try to pull myself out of it.

But it doesn't imply a FWD on ice is some sort of death trap or inherently dangerous. Its just different and you have to know what to do to recover correctly.

That being said... if I was going down a mountain I'd be pulling my emergency brake too, because that makes sense.

As for a freeway and black ice... frankly I think you are pretty screwed either way and I doubt either car is going to come through unscathed. At least thats my opinion. Thats why I don't drive like a maniac in any vehicle on the freeway, FWD, RWD, 4WD, AWD. I always laugh at the 4WD SUV's that buzz by me on the freeway thinking.... "yeah feels great to have that extra traction to go... but we all have four wheel brakes and frankly STOPPING is the real problem."

 

Willard, the traction motor/generator is connected to the ring gear of the planetary gear set. The traction motor is connected to the drive wheels through a series of gears and rotates whenever the wheels rotate. The exception is when the axle disconnect is activated by neutral or any other predetermined fault detected by the vehicle controller. The disconnect is not a clutch.

As you know, there is no reverse gear in the eCVT. The traction motor can propel the vehicle in reverse by reversing it's direction. The OWC prevents the engine from turning in the reverse direction and I believe engine braking from the wheels. Engine braking is only simulated through the traction motor through regen. If you shift to "L", the simulation is increased by a increase in regen. I use this simulation everyday to get a quicker recharge of my battery to almost double EPA MPG estimates for the FWD FEH.

There is a very important need for the axle disconnect as stated in the patent. The patent on discontinuing regen in cold weather addresses your very concern with traction. Ford has the first hybrid AWD SUV which is designed to operate better in snow and ice than most FWD vehicles.

Ford just got a patent for complete control of the wheels (YAW) preventing roll over which even over rides anti lock brakes and regen.
http://www.cleanmpg.com/forums/showthread.php?t=2262

Willard, let get closer to the day of the race to make plans for Starbucks. I'm planning on a FE group of people to meet for the Sebring race and also heading up for the hybridfest event. Don't know how much the wife can take yet.

GaryG

 

I rather doubt that the referenced patent can be applied to the FEH/MMH.

When overstearing is sensed by a VSC system the corrective method is to moderately apply the brake on the outside front wheel. Some systems will also quickly dethrottle the engine. If the brakes are already being used then the braking of the inside front wheel is lowered, moderated. If the vehicle should continue to overstear to the point wherein the vehicle's "moment" is beyond the centerline of the desired direction of movement then VSC is instantly deactivated.

If the vehicle is understearing, plowing, the most common action for VSC is to moderately brake both rear wheels while instantly dethrottling the engine. Some of the more upscale vehicles will only brake, or more heavily brake, the rear wheel on the inside of the turn.

It appears to me then if this patent were to apply to the FEH/MMH then some method would need to be developed so that regenerative braking could be made selective side to side. And since there doesn't seem to be any way to be selective about regenerative braking Front vs rear in the FEH/MMH vehicles the patent, again, cannot be applied.

In any case, absent controlling the stearing wheel itself(***), the corrective measures for over or under stearing involve side to side differential functions, something that quite clearly can be accomplished with the actual braking system, but I can't see how it could be done with the regenerative braking capability of the FEH/MMH.

***The new electric power stearing in the Toyota and Lexus models actually do interact with the VSC system. If the vehicle is over or under stearing the system will lower the assist level if you try to turn the stearing wheel in a direction that would make matters worse. I understand that for FWD models the electric assist is also used to "cancel" the effects of torque stear.