An orientation monitoring apparatus includes an inner spherical shell rigidly fixed within an outer spherical shell, and a spherical ball positioned between the two shells. The inner shell has a polar coordinate grid impressed on it so that the position of the ball relative to the grid is seen from above. An inertial platform is rotationally interfaced with the inner shell. This platform supports a video camera with a view of the grid and ball. As well, the platform supports a motor driven fly-wheel which keeps the platform in a desired horizontal attitude. The motor, camera and a computer are driven by a solar cell and storage battery also mounted onto the platform and which receives energy through the transparent shells. An optical recognition software driven by the computer, is used to automatically compute the movements of the ball relative to the grid so that rotational movements of the shells can be computed in three-space.
A platform monitoring system includes a camera for capturing a situation on a platform. An image captured by the camera is transmitted from a light emitter on the ground side as an optical signal and also transmitted from a transmission antenna on the ground side as a radio wave signal. These signals are received by an optical receiver and a reception antenna, respectively, mounted in a leading end portion of a vehicle. When the vehicle is positioned in a region around a stopping position, an image carried by the optical signal is selectively displayed on a monitor disposed near an operator's seat in the vehicle. When the vehicle is positioned out of the region around the stopping position, an image carried by the radio wave signal is selectively displayed on the monitor near the operator's seat in the vehicle.
