Active damping of engine idle speed oscillation by applying adaptive PID control.

摘要

In this research, we investigate the use of an adaptive proportional-integral-derivative (APID) controller to reduce a combustion engine crankshaft speed pulsation. Engine test rig experiments are used to validate the suggested control scheme. The integrated starter alternator damper (ISAD) is used as the actuator for engine speed control. The ISAD is an induction machine. It produces a supplemental torque source to cancel out the fast engine torque variation. This machine is placed on the engine crankshaft. The impact of the slowly varying changes in engine operating conditions is accounted for by adapting PID controller parameters on-line.; The APID control scheme tunes the PID controller parameters by using the theory of adaptive interaction. The tuning algorithm determines a set of PID parameters by minimizing an error function. The error function is a weighted combination of system states (output of the plant) and the required control effort (input to the plant). The tuning method is automatic and requires no human intuition or intervention. The algorithm is simple and can be easily implemented on-line as well as off-line. Two versions of the tuning algorithm are presented and applied to the problem of engine speed pulsation damping. These tuning algorithms are known as the Frechet and the approximation methods. The approximation method does not require the knowledge of the plant to be controlled; therefore, the control scheme becomes robust to plant changes and can be applied to a large class of linear and non-linear systems.; In this research, we also show that the APID control algorithm is mathematically equivalent to the MIT rule. Furthermore, we perform analytical study of the performance and the convergence properties of the APID tuning schemes. We use the Lyapunov theory to prove the stability of the approximation method.