Thispaperisconcernedoftheloopclosuredetectionproblemforvisualsimultaneouslocalizationandmappingsystems.Weproposeanovelapproachbasedonthestackeddenoisingauto-encoder(SDA),amulti-layerneuralnetworkthatautonomouslylearnsancompressedrepresentationfromtherawinputdatainanunsupervisedway.Differen