A train positioning method based on a dynamic map includes: performing train positioning initialization based on a positioning source, and obtaining key point information for creating the dynamic map; generating key point coordinates according to the key point information, and creating the dynamic map; updating a train position on the dynamic map according to train displacement and beacon information; updating the dynamic map, and updating the train position based on the updated dynamic map; and, converting an updated train position in the updated dynamic map into a standard track map, to achieve train positioning. A plurality of initialized positioning sources are used to obtain initialization positioning information of train key points, and creation of a dynamic map is completed.

A light apparatus for use with a power source and a control switch, the control switch including an input node, an output node and at least first and second independently selectable current paths between the input and output nodes, the first selectable current path having a resistance value that is greater than the second current path, controlling light intensity as a function of which of the current path is selected, at least one light source, a controller linked to the control switch and determining the selected path and generating a control signal and a light driver linked between the output node and the light source, the driver receiving the control signal and adjusting the current applied to the light source as a function of the control signal.

A light apparatus for use with a power source and a control switch, the control switch including an input node, an output node and at least first and second independently selectable current paths between the input and output nodes, the first selectable current path having a resistance value that is greater than the second current path, controlling light intensity as a function of which of the current path is selected, at least one light source, a controller linked to the control switch and determining the selected path and generating a control signal and a light driver linked between the output node and the light source, the driver receiving the control signal and adjusting the current applied to the light source as a function of the control signal.