Abstract: In order to provide a map suitable for a movable apparatus which autonomously moves, a map data generation device includes a spatial data acquisition unit configured to acquire spatial data generated by measuring an object present in a space with a sensor, an attribute data acquisition unit configured to acquire attribute data indicating an attribute of a movable apparatus which autonomously moves in the space, and a map data generation unit configured to generate map data which is used when the movable apparatus autonomously moves in the space on the basis of the attribute data and the spatial data.

Abstract: An oxygen sensor for determining the partial pressure of oxygen in a monitored gas environment includes a diffusion housing of zirconia based material having a gas diffusion aperture, an oxygen ion conductive plate of zirconia based material, a pair of electrode layers mounted on opposite sides of the conductive plate, and a sealing glass material sealingly bonding the conductive plate at one side to the housing to provide a diffusion chamber defined by the diffusion housing and the conductive plate. The electrodes are connectable to a power source for being supplied with an electric potential to pump oxygen ion out of the diffusion chamber through the conductive plate to flow a current through the electrodes which current is indicative of the partial pressure of the oxygen in the monitored gas environment. The sealing glass material contains SiO.sub.2, BaO, Na.sub.2 O and ZrO.sub.2.