Sliding door motion model building method and smoothness evaluation method

The invention provides a sliding door motion model building method and a smoothness evaluation method. The sliding door motion model building method comprises the following steps that the center point of an upper hinge guide wheel of a sliding door and an upper sliding rail operation plane are restrained through a point-surface pair; manufacturing a middle hinge intermediate ball, restraining the movable end of the sliding door middle hinge and the center of the middle hinge intermediate ball through a ball pair, and restraining the movable end of the sliding door middle hinge and the fixed end of the sliding door middle hinge through a rotating pair; a lower hinge intermediate ball is manufactured, the movable end of the lower hinge of the sliding door and the center of the lower hinge intermediate ball are restrained through a ball pair, the movable end of the lower hinge of the sliding door and the fixed end of the lower hinge of the sliding door are restrained through a rotating pair, and center points of