Design And Research On Expert PI Self-tuning Control Strategy For Diesel Engine In Steady Condition

The classic proportional-integral-derivative(PID)control offers the most efficient and simplest way in diesel electronic speed control.However,the properties of diesel engine would be changed with the abrasion,operating environment changing etc.So the PID control parameters could be no longer suitable with the diesel engine which could lead to heavy speed fluctuation and the controller could not govern the speed back to steady state.Few self-tuning strategy is used to solve this problem in practical due to convergence problem,complicated to calculate etc.This paper proposes an “intelligent” way to solve this problem.In steady condition,using the expert control strategy,imitating the logic and experience of manual adjustment,tuning Kp and Ki automatically according to the discrimination of the speed fluctuation.The experiment on D6114 diesel shows that the PI self-tuning software designed by this paper can make the diesel speed running back to steady state by tuning Kp and Ki automatically.The expert control strategy proposed in this paper has practical value in PI parameter tuning and diesel system self-rescue from the unstable state.