Radar-operated collision avoidance system for roadway vehicles using stored information for determination of valid objects

• US 4,072,945 A
• Filed: 12/02/1976
• Issued: 02/07/1978
• Est. Priority Date: 12/02/1975
• Status: Expired due to Term

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Katsumata, Masaaki, Fujiki, Norio
• Primary Examiner(s): Tubbesing, T. H.
• Application Number:
  US05/746,742
• Time in Patent Office: 432 Days
• Field of Search: 343/7 VM, 343/7
• US Class Current: 342/70
• CPC Class Codes: B60T 2201/022 Collision avoidance systems
• CPC Class Codes: G01S 1/16 Azimuthal guidance systems, e.g. system for defining aircraft approach path, localiser system
• CPC Class Codes: G01S 13/02 Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
• CPC Class Codes: G01S 13/91 for traffic control G01S13/93 takes precedence
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/93185 Controlling the brakes
• CPC Class Codes: G01S 2013/932 using own vehicle data, e.g. ground speed, steering wheel direction
• CPC Class Codes: G01S 2013/9322 using additional data, e.g. driver condition, road state or weather data

Abstract

A radar-operated collision avoidance system for a roadway vehicle comprises a radar device for sensing the vehicle speed relative to an object and its distance thereto to decide whether the vehicle is approaching the object at a dangerously high speed. A minimum allowable distance represented by a digital code is stored in a memory location within an array of rows and columns and read out in response to a sensed vehicle speed relative to the roadway and to a sensed magnitude of steering movement. The minimum allowable distance is compared with the distance sensed by the radar to determine that the decision is valid only when the latter is smaller than the former.

Claims

1. A collision avoidance system for a roadway vehicle having a steering wheel, including a radar device for sensing the distance from the vehicle to an object and the speed of the vehicle relative to said object, a decision making circuit responsive to said sensed distance and said relative speed to determine when the vehicle is approaching the object to a dangerously high speed, and a utilization circuit responsive to an output from said decision making circuit, wherein the improvement comprises:

means for detecting the speed of the vehicle relative to roadway;

means for detecting the magnitude of angular movement of said steering wheel;

means for storing information representing a minimum allowable distance from said vehicle to said object for a set of input variables;

means for reading the stored information in response to said detected vehicle speed and to said detected magnitude of angular movement of said steering wheel as a set of said input variables;

means for comparing the distance sensed by said radar device and the minimum allowable distance represented by the information read out from said storing means to generate an inhibit signal when said sensed distance is greater than said allowable distance; and

means for disabling said output signal from said decision making circuit in response to said inhibit signal.

2. A collision avoidance system as claimed in claim 1, wherein said storing means comprises a plurality of memory units arranged in an array of rows and columns, and said reading means comprises first means for addressing one of the rows of said array in response to the detected vehicle speed and second means for addressing one of the columns of said array in response to the detected magnitude of angular movement of said steering wheel.

3. A collision avoidance system as claimed in claim 2, wherein each of said memory units comprises a plurality of memory cells for storing said minimum allowable distance in binary representation.

4. A collision avoidance system for a roadway vehicle having a steering wheel, including a radar device for sensing the distance from the vehicle to an object and the speed of the vehicle relative to said object, a decision making circuit responsive to said sensed distance and said sensed relative speed to determine when the vehicle is approaching the object at a dangerously high speed, and a utilization circuit responsive to an output from said decision making circuit, wherein the improvement comprises:

means for detecting the speed of the vehicle relative to roadway;

means for detecting the magnitude of angular movement of said steering wheel;

a plurality of memory matrices each storing information representing a minimum allowable distance from said vehicle to said object for a particular set of input variables within an array of rows and columns;

means for selectively reading the stored information from one of said memory matrices in response to said detected vehicle speed and to said detected magnitude of angular movement of said steering wheel as a set of said input variables;

means for comparing the distance sensed by said radar device and the minimum allowable distance represented by the information read out from said one of the memory matrices to generate an inhibit signal when said sensed distance is greater than said allowable distance; and

means for disabling said output signal from said decision making circuit in response to said inhibit signal.

5. A method for detecting a valid object from a roadway vehicle having a steering wheel, comprising:

storing electrical quantities each representing a minimum allowable distance from said vehicle to an object for a given set of a speed of said vehicle relative to roadway and a magnitude of angular movement of said steering wheel in storage locations within an array of rows and columns;

sensing the speed of the vehicle relative to said roadway;

sensing the magnitude of angular movement of said steering wheel;

sensing the distance from said vehicle to said object;

relating said sensed vehicle speed and said distance to a particular location of said array of rows and column;

addressing the storage location in response to the sensed vehicle speed and said sensed magnitude of steering wheel movement to read out the electrical quantity stored in the addressed location;

sensing the speed of said vehicle relative to said object;

determining whether said vehicle is approaching said object at a dangerously high speed in response to said sensed vehicle speed relative to said object and to said sensed distance;

comparing the minimum allowable distance represented by the read out electrical quantity with said sensed distance; and

judging that said determination is valid when said sensed distance is smaller than said minimum allowable distance.