Steering column vibration reduced by cylinder pressure shaping
Steering column vibration reduced by cylinder pressure shaping
(OP)
According to this: https://www.hondarandd.jp/point.php?pid=1033&l...
...P&E engineers have allowed fundamental changes to breathing and combustion to reduce steering column vibration. I haven't read the actual article, but it sounds a little far-fetched. Interested to hear similar anecdotes.
Quote:
During development of the 2014 model-year Accord Hybrid, for which the SPORT HYBRID i-MMD new model hybrid system was adopted, 2nd-order vibration transmitted to the steering became an issue. This occurred because the vehicle has higher engine net torque than a gasoline engine vehicle, so that there is larger crankshaft revolution 2nd-order fluctuation, which is the source of the vibration. There is concern that using only reduction of engine net torque as the means to lessen crankshaft revolution 2nd-order fluctuation could cause an increase in the brake-specific fuel consumption. Therefore the combustion control parameters, such as ignition timing and valve operation timing, were changed as a way of optimizing crankshaft revolution 2nd-order fluctuation, engine net torque, and brake-specific fuel consumption. These measures achieved the steering vibration target while also determining the optimal point where the amount of engine net torque reduction could be lessened by 5 Nm and 1% of the increase in brake-specific fuel consumption could be recovered.
...P&E engineers have allowed fundamental changes to breathing and combustion to reduce steering column vibration. I haven't read the actual article, but it sounds a little far-fetched. Interested to hear similar anecdotes.
- Steve





RE: Steering column vibration reduced by cylinder pressure shaping
So, could you modify the combustion pressure such that the second order component is reduced, and yet the torque (the integral of all the harmonics) stays the same?
Cheers
Greg Locock
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RE: Steering column vibration reduced by cylinder pressure shaping
If this is a hybrid vehicle with a flywheel-centric electric motor, why not just actively cancel the undesired vibrations electrically?
RE: Steering column vibration reduced by cylinder pressure shaping
- Steve
RE: Steering column vibration reduced by cylinder pressure shaping
RE: Steering column vibration reduced by cylinder pressure shaping
- Steve
RE: Steering column vibration reduced by cylinder pressure shaping