Tumble-detecting apparatus and passenger conveyor

The invention provides a tumble-detecting apparatus and a passenger conveyor. The tumble-detecting apparatus can avoid fault detection when the sensor hood is covered by a foreign body. The tumble-detecting apparatus comprises a scanning distance sensor which, arranged at the passageway of the passenger conveyor, ejects laser beams. The scanning distance sensor stores the distances detected according to every angle, and calculates the standard deviation of the data distance varying with time and the standard deviation of the standard deviation according to the data within the set detecting area. When the standard deviation is below threshold value and the standard deviation of the standard deviation is below the threshold vale, the surface dimension of the object in the area is calculated. If the state that the surface dimensions of the object is beyond the threshold value lasts the preset duration, then the state is judged as the tumble state. The distance to the object is calculated. If the distance to the object is around the scanning distance sensor and the state that the surface dimensions of the object is beyond the threshold value lasts the preset duration, the object is detected to be a foreign body as fault detection.