Communications: directive radio wave systems and devices (e.g. – Directive – Including a satellite
Reexamination Certificate
1998-11-19
2001-05-15
Tarcza, Thomas H. (Department: 3662)
Communications: directive radio wave systems and devices (e.g.,
Directive
Including a satellite
C342S452000, C701S201000, C701S206000, C701S208000, C701S210000, C701S209000, C701S211000, C340S995190
Reexamination Certificate
active
06232917
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to the field of navigational systems, and more particularly to a system, device and method of operation that provides the user with current information on the immediate environment and a route to a selected destination.
BACKGROUND OF THE INVENTION
Systems for providing positional and navigational information are known in the art. Typically, these systems utilise signals derived from a Global Positioning System (GPS) such as the NAVSTAR system.
Navstar was developed to provide accurate position, velocity, and time information in any environmental conditions. The system includes twenty-four satellites arranged in six orbital planes such that the satellites orbit the planet in circular orbits with a twelve hour period. The satellite orbits are arranged such that at least four satellites are in “view” (i.e. not obscured by the curvature of the planet) from any position on the planet.
Each user module receives periodically transmitted signals from four satellites. The user unit computes a range to each satellite based upon the known time of receipt of the signal, and a predicted time of transmission of the signal from the satellite. GPS systems commonly have two standards of operation; a military standard and a civilian standard. Systems operating according to the military standard provide a positional accuracy of 16 meters, a velocity accuracy of 0.1 meters per second, and a time accuracy to 100 nanoseconds. However, the signals transmitted by the satellites according to the military standard are encrypted to prevent unauthorised access. Comparably, systems operating according to the civilian standard provide a positional accuracy of 100 meters.
Vehicle navigational systems are well known in the art. For example, European Patent Application No. EP-A-0,542,331 discloses a vehicle navigational device for directing a vehicle along a predetermined route. The device utilises GPS positional data displayed on a display unit within the vehicle
The “Route Planner” system manufactured by TECmobility™ a subsidiary of Magneti Marelli is a navigational device that provides positional information of a vehicle relative to a map, together with a route planning capability. The position of the vehicle is estimated using positional data from signals received from GPS satellites. The actual position of the vehicle is then corrected by algorithms that relate the positional data computed from received GPS signals to a corresponding position on map of the current location of the vehicle stored on a CD-ROM.
The route planning function calculates the best route between the current vehicle location and a user selected destination. The system is capable of recalculating the route should the user deviate from the predetermined route due to adverse traffic conditions etc. The system is further capable of receiving data relating to the conditions on the predetermined route, and recalculating the route in accordance with the received traffic conditions etc.
However, although the system is capable of receiving data for causing the recalculation of the predetermined route due to adverse traffic conditions, the system is not capable of proactively recalculating the route due to the planned route calculations of other users of the system. For example, a user may be provided with a predetermined route which takes account of the current traffic conditions, but the system takes no account of the predicted travel conditions on the route within the travel period of the user. Consequently, although the selected route may be determined in accordance with the traffic conditions at the time of route determination, the predetermined route may be less appropriate when considering the intentions of other road users.
SUMMARY OF THE INVENTION
The present invention provides a system, device, and method for providing navigational information to a user that is calculated in accordance with known current travel conditions. The navigational information provided to the user is further calculated in response to the predicted travel conditions during the period when the user will be present at a way-point on the route between the initial position and the destination. The navigational information is interpreted in the context of local environmental information.
Therefore, according to a first aspect of the present invention there is provided A navigational system comprising; a plurality of transmitters for transmitting a clocking signal to a user module; the user module including; a processor for computing the range to each of the plurality of transmitters based upon the corresponding clocking signals received therefrom, and for determining a current position relative to each of said plurality of transmitters; designation means for sequentially designating and storing a sequence of reference points defining said current position relative to an initial position and a selected final position; a memory for storing geographical data relating to at least the current position of the user module; selection means for selecting geographical data relating to the current location of the user module based upon the determined current position; a display for providing an audio or video display of the selected geographical data and the current location of the user module relative thereto, and for providing an indication to the user of the distance and direction to a subsequent reference point in said sequence; and transmission means for transmitting said designated sequence of reference points to a control processor associated with at least one of said plurality of transmitters.
The data signals transmitted by the transmission means preferably comprise a geographical data component providing information on the current environment, and a positional data component the processor with information necessary to determine the instantaneous position of the receiver. For example, the geographical data may comprise a map of the current location or details of places of interest.
Preferably, the user module polls one of the transceivers, and receives geographical data relevant to the instantaneous environment of the receiver from the transceiver in response to being polled. The received geographical data is then stored in the memory.
Preferably geographical data can be provided to the memory for storage by coupling the user module to an external device. The external device may comprise a computer linked to a database via a network or modem, or comprise a CD-ROM, floppy disk or other suitable data storage medium.
The user is provided with a keyboard or other suitable data entry device for selecting a route between the current location and a destination location. A first reference point is assigned to the current location and a second reference point is assigned to the destination location. Further locations between said current location and said destination location may be selected and are assigned reference points accordingly.
According to a second aspect of the present invention there is provided a user module for a navigational system comprising; a receiver for receiving clocking signals from a plurality of transmitters; a processor for computing the range to each of the plurality of transmitters based upon the corresponding clocking signals received therefrom, and for determining a current position relative to each of said plurality of transmitters; designation means for sequentially designating and storing a sequence of reference points defining said current position relative to an initial position and a selected final position; a memory for storing geographical data relating to at least the current position of the user module; selection means for selecting geographical data relating to the current location of the user module based upon the determined current position; a display for providing an audio or video display of the selected geographical data and the current location of the user module relative thereto, and for providing an indication to the user of the distance and direction to a subsequent refere
Baumer Jean-Claude
Giacalone Jean-Claude
Hilbig Hans-Martin
Kempler William B.
Mull Fred
Tarcza Thomas H.
Telecky , Jr. Frederick J.
Texas Instruments Incorporated
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