Route guidance system for roadway vehicles
First Claim
1. A route guidance system for roadway vehicles for conveying thereto aural routing information from a central monitoring station in accordance with monitored traffic data, comprising:
- remotely located stations each being connected over a communication channel to said central station and adapted to receive inquiry signals transmitted from a vehicle in a specified area of a roadway and in response to transmit routing information to the same vehicle within the specified area, each of said stations comprising multiple location, addressable storage means for storing at respective different storage locations a plurality of different pieces of routing information received from said central station, means for receiving modulated electromagnetic energy including a destination code signal transmitted from said vehicle, means for demodulating said received electromagnetic energy, means at the remote station and responsive to said destination code for addressing said storage means to select a particular piece of routing information from said storage means, time-compression means for compressing the time dimension of said selected routing information, means for modulating electromagnetic energy with the time-compressed routing information, and means for transmitting the modulated electromagnetic energy to said vehicle; and
a vehicle unit comprising means for generating said destination code signal in response to said vehicle entering said specified area, means for modulating electromagnetic energy with said destination code signal, means for transmitting the modulated electromagnetic energy to said remote station for addressing a particular piece of routing information stored at a particular storage location in said remote station, means for receiving the electromagnetic energy transmitted from the remote station, means for demodulated the received electromagnetic energy, time-expansion means responsive to said demodulating means for expanding the time dimension of said demodulated energy to recover said selected piece of routing information, and means for electroacoustically transducing said audio routing information in audible form in said vehicle.
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Abstract
A central station of a route guidance system collects traffic data from various points of a city area and updates aural routing information stored in roadside remote stations at periodic intervals. A moving vehicle senses the location of a roadside station to transmit a coded destination signal thereto where it is decoded to retrieve desired routing information. The latter is compressed in time dimension and transmitted back to the vehicle for storage in a storage device which is later retrieved at such a rate as to reproduce the original aural information.
81 Citations
19 Claims
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1. A route guidance system for roadway vehicles for conveying thereto aural routing information from a central monitoring station in accordance with monitored traffic data, comprising:
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remotely located stations each being connected over a communication channel to said central station and adapted to receive inquiry signals transmitted from a vehicle in a specified area of a roadway and in response to transmit routing information to the same vehicle within the specified area, each of said stations comprising multiple location, addressable storage means for storing at respective different storage locations a plurality of different pieces of routing information received from said central station, means for receiving modulated electromagnetic energy including a destination code signal transmitted from said vehicle, means for demodulating said received electromagnetic energy, means at the remote station and responsive to said destination code for addressing said storage means to select a particular piece of routing information from said storage means, time-compression means for compressing the time dimension of said selected routing information, means for modulating electromagnetic energy with the time-compressed routing information, and means for transmitting the modulated electromagnetic energy to said vehicle; and a vehicle unit comprising means for generating said destination code signal in response to said vehicle entering said specified area, means for modulating electromagnetic energy with said destination code signal, means for transmitting the modulated electromagnetic energy to said remote station for addressing a particular piece of routing information stored at a particular storage location in said remote station, means for receiving the electromagnetic energy transmitted from the remote station, means for demodulated the received electromagnetic energy, time-expansion means responsive to said demodulating means for expanding the time dimension of said demodulated energy to recover said selected piece of routing information, and means for electroacoustically transducing said audio routing information in audible form in said vehicle. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A remotely controlled device adapted to be located in use adjacent to a roadside and connected in use to a central route guidance station over a communication channel to receive aural routing information from the central station to be transmitted to a moving vehicle requesting aural routing information while said vehicle is within a specified area of a roadway, comprising:
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a transmitter for generating electromagnetic energy in the microwave frequency range to direct it through a directive antenna toward the roadway surface; a receiver connected in use to said antenna for detecting information contained in microwave energy transmitted from a moving vehicle and captured by said antenna, said vehicle transmitted microwave energy including a destination code signal; means for providing quantization of said aural routing information received from said central station; storage means including multiple storage locations at said roadside device for storing respectively plural pieces of said quantized information; storage control means for causing said storage means to successively store the plural pieces of quantized information in respectively different storage locations of said storage means in said roadside device, said storage control means being responsive to said destination code signal at the output of said receiver for addressing said storage means to deliver a piece of stored quantized information corresponding to said location code signal, said storage control means further including means for causing said storage means to successively deliver the addressed piece of stored quantized information at a rate much-higher than the rate at which said piece of quantized information has successively been stored, said transmitter including modulation means for modulating said microwave energy with said delivered piece of quantized information, whereby a specified area of the roadway is irradiated with unmodulated microwave energy in the absence of a vehicle in said specified area and irradiated with modulated microwave energy in the presence of a vehicle in said specified area.
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17. In a route guidance system having a central station from which aural routing information is issued and a remotely located roadside station in communication with said central station over a communication channel to receive said routing information, said roadside station including storage means, means for quantizing the received routing information, means for storing different pieces of the routing information respectively in different storage locations of said storage means at said roadside station, means for receiving microwave energy transmitted by a moving vehicle within a specified area of a roadway requesting routing information, said transmitted microwave energy including a destination code signal, said roadside station further including means for addressing said storage locations in response to said received destination code signal to generate a particular piece of routing information and means for transmitting said particular piece of routing information to the roadway surface in the form of microwave radiation to be received by said moving vehicle, a vehicle unit, comprising:
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a transmitter for generating electromagnetic energy in the microwave frequency range to be propagated by a directive antenna mounted on the vehicle; a receiver at said vehicle responsive to energy received by said antenna for detecting quantized information contained in the microwave radiation transmitted from said roadside station and received by said vehicle antenna; a detector for detecting when said vehicle enters the specified area of the roadway; destination code generating means at said vehicle responsive to the output of said detector to generate the destination code, said transmitter including means for modulating said microwave energy with said destination code; storage means; storage control means for causing said storage means to successively store the information detected by said receiver and effective after completion of the storage of said information for causing said storage means to successively deliver said stored information at a rate much lower than the rate at which said information has successively been stored; and dequantization means for dequantizing said delivered quantized information to recover the original aural routing information for reproduction through an electroacoustic transducer.
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18. A method for conveying aural routing information to a moving vehicle while said vehicle is within a specified location from a central station, comprising the steps of:
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(a) transmitting pieces of said aural routing information from said central station to a remotely located station over a communication channel; (b) storing said pieces of transmitted routing information respectively in different storage locations of a storage device located in said remote station; (c) generating electromagnetic energy and radiating it toward the roadway surface of said specified location through a first directive antenna mounted fixedly adjacent said specified location; (d) detecting said radiated energy in said vehicle as it passes through said specified location; (e) transmitting a destination code signal in the form of electromagnetic energy through a second directive antenna mounted on said vehicle toward said first antenna in response to the detection of said radiated energy in the step of (d); (f) detecting said destination code at said remote station; (g) addressing said storage device in response to said destination code signal to generate a particular piece of stored routing information; (h) transmitting the stored routing information, generated by said addressed storage means, in the form of electromagnetic energy through said first antenna to said second antenna while said vehicle is within the specified location within a smaller interval than the interval within which said aural information is reproduced for human intelligibility; (i) detecting the particular piece of routing information so transmitted from the first antenna at said vehicle; (j) successively storing the detected particular piece of routing information in a storage device located in said vehicle; (k) retrieving the stored particular piece of routing information from said storage device of the vehicle in succession to the completion of the step (j) within a longer interval than the interval within which said detected particular piece of routing information has been stored in the step (j); and (l) electroacoustically converting the retrieved information into an audible signal. - View Dependent Claims (19)
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Specification