Doppler navigation method for determining the distance travelled by a vehicle
AssigneeInstitut Francais du Petrole
InventorRobert Delignieres
Life of this patent
Estimating the term…
Abstract
Method and apparatus for determining the distance travelled by a vehicle with respect to a reference surface from the frequency shift between the frequency of signals transmitted from the vehicle and the frequency of echo-signals reflected on said surface in which the transmitted signals consist of a series of pulses of variable recurrence period whose duration is shorter than the propagation time interval of said signals from the transmission point to the reception point of the echo-signal and in which the frequency of the signals constituting said pulses is variable during the period of each pulse.
Claims16
A device for determinining the distance travelled by a vehicle movable with respect to a reference surface, comprising means for transmitting signals along at least one transmission direction inclined with respect to the reference surface, means for receiving echo signals corresponding to the transmitted signals on said surface, and means for measuring the distance travelled by the vehicle with respect to said surface, said transmitting means including memory means for storing repetitive data sequences, selection means for selecting the address of the data stored in said memory means and for controlling the extraction thereof, clock means for producing clock pulses defining time scales, means for producing signals whose frequencies are proportional to those of the clock frequencies and which depend on the values of the repetitive data sequences, and control means for activating the selection means in response to signals corresponding to the preselected values of said sequences.
A device for determining the distance travelled by a vehicle with respect to a reference surface, comprising means for transmitting signals along at least one transmission direction inclined with respect to said reference surface, said transmitting means including means for producing an uninterrupted series of pulses, whose recurrence period is variable and whose frequency is variably during the period of each pulse, means for receiving echo signals corresponding to the transmitted signals on said surface, and means responsive to said receiving means for measuring the distance travelled by the vehicle with respect to said surface, said producing means including clock means for generating clock pulses and a system for generating signals whose frequencies are proportional to those of the clock pulses, said system comprising a signal generating means arranged for alternate positioning in two different states, and control means for alternately positioning said signal generating means at successive moments separated by time intervals depending on the period of the clock pulses and on repetitive data sequences of predetermined values.
A method for determining the distance travelled by a vehicle movable with respect to a reference surface, comprising the steps of transmitting from the vehicle along at least one transmission direction inclined with respect to the surface, an uninterrupted series of pulses whose recurrence period is variable and shorter than the propagation time interval between the transmission and reception of the signals, the pulses being comprised of signals which are variable in frequency during the period of each pulse, receiving echo signals corresponding to the transmitted signals after reflection from the surface, and measuring the distance travelled by the vehicle from the frequency shift between the frequency of the transmitted signals and that of the signal received along the transmission direction, the step of transmitting said series of pulses including controlling a pulse generating means by signals whose periods depend on clock pulses defining time scales and on predetermined values stored in a storage means.
A method for determining the distance travelled by a vehicle movable with respect to a reference surface, comprising the steps of transmitting from the vehicle along at least one transmission direction inclined with respect to the surface of an uninterrupted series of pulses whose recurrence period is variable and shorter than the propagation time interval between the transmission and reception of the signals, the pulses being comprised of signals which are variable in frequency during the period of each pulse, receiving echo signals corresponding to the transmitted signals after reflection from the surface, and measuring the distance travelled by the vehicle from the frequency shift between the frequency of the transmitted signals and that of the signal received along the transmission direction, the step of transmitting said series of pulses including controlling a pulse generating means by signals whose periods are proportional to predetermined values stored in storage means and to clock pulses defining two different time scales.
Dependencies are inferred from the claim text.