On-Vehicle Apparatus, And Method And Computer Program For Transmitting Positional Information

A method of generating and sending positional information pieces representative of positions of a vehicle, comprising the steps of:

• generating, at every first prescribed timing, a positional information piece representing a position of the vehicle which occurs at the first prescribed timing;
• writing the generated positional information piece into one of storage areas in a storage device;
• sending positional information pieces in the storage areas to a positional information collecting apparatus at every second prescribed timing, and allowing new positional information pieces to be written into the storage areas in which the sent positional information pieces are stored;
• and
• in cases where sending the positional information pieces in the storage areas to the positional information collecting apparatus is impossible, allowing a new positional information piece or pieces to be written into one or more of the storage areas which store a positional information piece or pieces having not been sent yet.

An on-vehicle apparatus comprising:

• a storage device including a plurality of storage areas;
• an information generating section for sequentially generating positional information pieces each representing a current position of the vehicle, and for writing the generated positional information pieces into the storage areas;
• a communication condition deciding section for repetitively deciding whether communications with an external information collecting apparatus are possible or impossible;
• and
• a controlling section for, each time the communication condition deciding section decides that communications with the external information collecting apparatus are possible, sending positional information pieces in the storage areas to the positional information collecting apparatus, and for, each time the communication condition deciding section decides that communications with the external information collecting apparatus are impossible, allowing a positional information piece or pieces to be erased from one or more of the storage areas.

A positional information collecting apparatus for collecting positional information pieces from a plurality of on-vehicle apparatuses, wherein each of the on-vehicle apparatuses generates, at every first prescribed timing, a positional information piece representing a position of the related vehicle which occurs at the first prescribed timing, and writes the generated positional information piece into one of storage areas, and sends positional information pieces in the storage areas to the positional information collecting apparatus at every second prescribed timing, and allows new positional information pieces to be written into the storage areas in which the sent positional information pieces are stored, the positional information collecting apparatus comprising:

• a communication load detecting section detecting a communication load being a load of communications with the on-vehicle apparatuses;
• and
• a condition deciding section for deciding a condition in response to the communication load detected by the communication load detecting section, and sending the decided condition to the on-vehicle apparatuses;
• wherein the decided condition is designed so that in cases where it is impossible for each of the on-vehicle apparatuses to send positional information pieces in the storage areas to the positional information collecting apparatus, the decided condition will be a condition of using one or more of the storage areas from which a positional information piece or pieces have not been sent yet as a storage area or areas into which a new positional information piece or pieces are allowed to be written, and that a number of the storage area or areas used as a storage area or areas into which a new positional information piece or pieces are allowed to be written will increase as the communication load detected by the communication load detecting section is greater.