methods to measure steering wheel inertia and friction? 1

[HondaRD]

Hi. I am currently studying chassis dynamics and would like to know what measuring devices are currently used to measure steering wheel inertia and steering system friction. Thanks!

 

[GregLocock]

1) Trifilar suspension

2) No simple method, but a series of component by component measurments and substitutions using force gauges and an instrumented steering wheel to give steering wheel torque gets you close enough.



Cheers

Greg Locock

 

[hpfreak]

Steering system friction is important on the "driver side" of the system more than the "hydraulic side". The difference is the driver side is unboosted and the hydraulic side is boosted. Friction has a large affect on steering feel and returnability on the driver side. You can measure the friction on the driver side by building a dummy gear. The dummy gear should have only the input shaft in it to locate the steering shaft. (No seals and no rack) Then install the dummy gear and measure the torque to turn the steering wheel using a torque wheel. Hydraulic side friction should be available from the gear supplier as part of standard testing of the rack.

 

[GregLocock]

I disagree with your emphasis. Many real world manouevres are strongly affected by the seal drag and the rack friction.



Cheers

Greg Locock

 

[SusTestEng]

I completely agree with Greg! Our steering shafts sit in very expensive bearings, and have very little friction. On the otherhand, the friction of the system is mostly a factor of the rack friction, which is set by the suplier(our focus area for steering effort adjustment), and the torque required to spin the tie-rod ball joint.

 

[hpfreak]

Ok, you disagree. How about methods of measurment?

 

[GregLocock]

Part by part measurement and substitution, as I said.

Cheers

Greg Locock