2020 年 56 巻 2 号 p. 67-69
We consider rechargeable batteries used in a start-stop system in automobiles, which automatically shuts down and restarts the engine. When the start-stop system is activated, it is necessary to check in advance whether batteries can serve sufficient power for restarting the engine and to judge whether the engine should be stopped. To make the judgement, the unit step response in a specified time of an internal impedance of batteries is used as a criterion. In this report, we propose to utilize an impulse response model to calculate the unit step response in a specified time. In particular, we illustrate the µ-Markov model, which consists of the finite impulse response model and the auto-regressive with exogenous input model, is suitable for the purpose. The effectiveness of the proposed method is demonstrated in a numerical experiment.