DOPPLER RADAR FOR LAND VEHICLES

• US 3,859,660 A
• Filed: 02/14/1972
• Issued: 01/07/1975
• Est. Priority Date: 02/14/1972
• Status: Expired due to Term

• Current Assignee: Carroll F. Augustine, Raymond E. Anderson
• Original Assignee: Carroll F. Augustine, Raymond E. Anderson
• Inventors: Augustine, Carroll F., Anderson, Raymond E.
• Primary Examiner(s): Wilbur, Maynard R.
• Assistant Examiner(s): Birmiel, H. A.
• Application Number:
  US05/226,108
• Time in Patent Office: 1,058 Days
• Field of Search: 343/8,9,7ED
• US Class Current: 342/114
• CPC Class Codes: G01S 13/60 wherein the transmitter and receiver are mounted on the moving object, e.g. for determining ground speed, drift angle, ground track G01S13/64 takes precedence

Abstract

A doppler radar system for automobiles and the like which is especially adapted for measuring vehicle speed. Preferably two radar antennas are utilized, one of which is forwardly and downwardly directed and the other of which is rearwardly and downwardly directed. The doppler signals from each of the antennas are summed to provide a velocity signal which is compensated for changes in the pitch of the vehicle. The system incorporates a circuit for distinguishing between phase shifts due to vertical vibratory motions of the vehicle when the vehicle is not moving longitudinally along the traveling surface and doppler shifts when the vehicle is moving longitudinally so that the system is only responsive to the doppler shifts.

Claims

1. In combination with a land vehicle traveling longitudinally along a roadway for the land vehicle, a system comprising:

generating and doppler detecting means for generating high frequency electromagnetic energy and for providing a signal representative of a phase shift between a returned part of said high frequency energy and a generated part of said high frequency energy;

directing and receiving means directing at least a portion of said generated energy along an axis intersecting with said roadway and receiving along said axis a returned part of said generated energy directed along said axis; and

signal processing means receiving said signal including means responsive to the amplitude of said signal for distinguishing between one portion of said signal representative of phase shifts due to a doppler effect and another portion of said signal due to another effect, said distinguishing means including doppler responsive means having an input means, an output means providing an output signal, and a feedback means connected between said input means and said output means for providing a feedback signal, said input means being connected to receive said signal and said feedback signal, said feedback signal being provided in opposition to said signal whereby a signal of predetermined amplitude at said input is required to effect a predetermined change in said output signal, and said distinguishing means further including an AND means having a pair of inputs and an output for providing an output signal in accordance with predetermined signals at both of said inputs, said signal being connected to one of said AND means input and said output signal of said doppler responsive means being connected to said other input of said AND means whereby the receipt by said AND means of both said output signal from said doppler responsive means and said signal provides an output from said AND means which is representative of phase shifts due to a doppler effect consequent longitudinal movement of said land vehicle.

2. A system according to claim 1 wherein said other portion of said signal is due to vertical motions of said vehicle.