Thoughts on crank angle sensing

[robert dingli]

Paul Campbell writes,

...
> As for instantaneous acceleration, another op-amp circuit can do a high pass
> filter on the PLL's output. From acceleration, we can also calculate
> instantaneous torque. By looking for peaks in this signal (another PLL or
> another derivative?), the position of maximum torque can be located.

This is a little bit more complicated than it may appear.  The instantaneous
acceleration of your slotted wheel it only indirectly related to the torque
output of the engine.  With much less resolution (60 teeth) than you propose,
I have struck crankshaft resonance, driveshaft and dynomometer characteristics
which make the calculations more complicated.  Single cylinder test engines
give good results but in the real world, multiple cylinders and external
loads are difficult to analyse.

For reference try SAE 945017,950005,890885,890884,900487,890486 etc.

It's a great idea though.

Robert

-- 
    Robert Dingli   r.dingli at ee.mu.oz.au
Power and Control Systems    (+613) 9344 7966
Thermodynamics Research Labs (+613) 9344 7712
     University of Melbourne, AUSTRALIA 
**  he who dies with the most toys, wins  **