I’ve never seen an ICE car need two engines to drive all four wheels. Why do EVs need 2 motors? Wouldn’t a transmission be cheaper than another motor?
I’ve never seen an ICE car need two engines to drive all four wheels. Why do EVs need 2 motors? Wouldn’t a transmission be cheaper than another motor?
Pretty sure you can direct these motors to behave however you want them to behave with the right sensors and software. I also don’t see why locking is inherently important - the important thing is putting power to wheels that have traction and not spinning the wheels that don’t. The quad motor configuration would use the computer to accomplish that rather than mechanical linkages which would be much less intelligent about dispatching torque.
While software can be used to manage traction it will always be reactive in a way mechanical lockers aren’t. The reason a locker is so good for offroading is because the wheels spin at the same speeds, preventing power “leaking out of the system” via wheelslip because the grip of every other locked wheel prevents a single low-traction wheel from slipping.
Independently powered wheels don’t have the proactive traction-management of mechanical lockers and thus are limited to reactive traction-management. That’s not to say independent motors can’t be extremely effective off-road, but mechanical-lockers will be more capable in serious offroading. The physical connection of mechanical lockers work in real-time.
This just isn’t very accurate as far as I can tell. The physical strain characteristics of a steel transfer case and drivetrain respond to forces in approximately 1ms (the speed of sound in steel over a 14 ft linkage). That’s the same speed resolution as a good quality computer controlled system. They’re exactly as “reactive”.
There’s nothing “delayed” about a good computer drive system, even compared to mechanical linkages. A well programmed computer system would be superior in every possible way. And you could just program it to only ever allow wheels to spin at exactly the same speed, exactly duplicating a mechanical linkage, with zero disadvantages (and much less complexity).