Gyroscope Application

[butelja]

Surely someone in the past has had this idea before. If anyone knows of any published reports or patents dealing with this or a similar idea, I'm curious for more details.

Here it is: A relatively large gyroscope is rigidly mounted in a vehicle at the vehicle's center of gravity with its spin axis in the horizontal plane perpendicular to the cars longitudinal axis. The gyro's spin rate is proportional to the vehicle's forward speed. When the vehicle is executing a turn, the gyroscope is precessed by the vehicle's yaw rate. The gyroscope in turn exerts a torque via the right hand rule on the chasis that counteracts the lateral load transfer the car would otherwise encounter due to lateral acceleration. Since the load distribution side to side is maintained equally even in a turn, the cornering capability should be improved.

Possible downside would be a huge increase in rotating mass, which would negatively affect acceleration and fuel efficiency. Also, packaging and safety would be concerns. But, has it been tried before?

 

[borjame]

I don't know if anyone used it on that scale but the Segway motorscooter uses a significant gyroscope to stabilize itself. The Segway is that "IT" thing the news talked about for over a year, it only has two wheels but balances itself using gyroscopes. Kind of similar, yes, no?

 

[gunsmith]

Hi BUTELJA,

stabilizing systems depending on gyroscopes were used on ships, rockets and aircrafts to held the radar system in a parallel layer to the surface of the sea or ground while the vehicle is moving. There are three gyroscopes, each for every axis x/y/z. The principle seems to be the same as yours. I don´t know the right expression in English, but is something like "virtual horizont". V1 and V2-rockets during the last war had such a system (without radar) built in to be guided by a virtual "north pol".

Andreas

 

[IRstuff]

The Segway scooter uses a solid state gyro that provides the error signals to the motor control electronics. What you are talking about here would require a substantial flywheel, which would add to the weight, complexity and potential danger to driving, since the gain of the gyro is a function of its rotation speed. There are much more efficient solutions at significantly lower weight.

TTFN

 

From what I have learned in dynamics class last year,there are two reasons you don't see this in cars:

1) They would be too heavy in order to produce effects that would make any difference in cornering.

2) Another reason that you don't use a gyro in a car is that if the car let go and started to spin a 360 (ie the car started to spin due to too large a cornering force), the revolution of the car could make the gyro produce such a large torque (due to the quick rotation of the rear end around the front) that it could flip the car over. This could very easily happen in wet, icy conditions.

So from a safety standpoint it is very dangerous to have cars flipping over if they spin-out.

 

[butelja]

Wicekdtl brings up a good point with respect to what happens after loss of tire adhesion. Without some sort of mechanical "fuse" or weak link to break in the system, the high yaw rate during oversteer could very easily cause catastrophe. This might be partially overcome by setting up the car to ensure understeer, but if done to excess then all potential advantage is lost. If the car is rolled over by the gyro due to excess yaw rate, the rolling motion would cause the gyro to exert a huge yawing torque. And vice versa. Sounds like a wild one way (terminal) ride. Probably not such a good idea after all.

Possible a better solution would be a laterally movable dead weight that is positioned via a signal from a small (instrument) yaw rate gyro. This would shift the center of gravity. Still the problem of adding excess weight and packaging concerns.

 

[hpfreak]

If the speed of the rotating mass is proportional to vehicle speed, there would be constant acc & dec of the rotating mass which also puts a torque on the vehicle and requires significant power.