Conventional detection schemes of input estimation filter may exhibit limited ability in the presence of low-level maneuvers. In this paper, a new detection scheme called the detectable maneuver set scheme is proposed by incorporating the trade-off property between target maneuver magnitude and detection time delay. With this new detection scheme, low-level maneuvers can be detected without enlarging the window size. The proposed detection scheme is applied to a 1-dimensional tracking problem. Simulation results show that the proposed scheme gives more consistent estimation of maneuver onset time and smaller detection delay than the conventional detection schemes.