Obstacle proximity detector for moving vehicles and method for use thereof

• US 4,833,469 A
• Filed: 08/03/1987
• Issued: 05/23/1989
• Est. Priority Date: 08/03/1987
• Status: Expired due to Fees

• Current Assignee: Constant V. David
• Original Assignee: Constant V. David
• Inventors: David, Constant V.
• Primary Examiner(s): Orsino, Joseph A.
• Assistant Examiner(s): Jackson, Jill D.
• Application Number:
  US07/080,953
• Time in Patent Office: 659 Days
• Field of Search: 340/901, 340/903, 340/904, 340/52 H, 340/552, 340/554, 340/555, 340/556, 340/557, 350/354, 350/356, 350/357, 350/358, 180/167, 180/169, 342/125
• US Class Current: 340/901
• CPC Class Codes: B60K 31/0008 including means for detecting potential obstacles in vehicle path
• CPC Class Codes: B60Q 1/535 to prevent rear-end collisions, e.g. by indicating safety distance at the rear of the vehicle
• CPC Class Codes: B60Q 5/006 indicating risk of collision between vehicles or with pedestrians
• CPC Class Codes: B60Q 9/008 for anti-collision purposes
• CPC Class Codes: B60T 2201/022 Collision avoidance systems
• CPC Class Codes: B60T 7/22 initiated by contact of vehicle, e.g. bumper, with an external object, e.g. another vehicle , or by means of contactless obstacle detectors mounted on the vehicle
• CPC Class Codes: B60W 2710/0605 Throttle position
• CPC Class Codes: B60W 2710/065 Idle condition
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 15/931 of land vehicles
• CPC Class Codes: G01S 17/48 Active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/931 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 2013/9323 Alternative operation using light waves
• CPC Class Codes: G01S 2013/9324 Alternative operation using ultrasonic waves
• CPC Class Codes: G01S 2013/9325 for inter-vehicle distance regulation, e.g. navigating in platoons
• CPC Class Codes: G01S 2013/93271 in the front of the vehicles
• CPC Class Codes: G08G 1/165 for passive traffic, e.g. including static obstacles, trees
• CPC Class Codes: G08G 1/166 for active traffic, e.g. moving vehicles, pedestrians, bikes

Abstract

A proximity sensing and indicating system for use in automobiles for instance to provide a warning signal to both the car driver and possibly other drivers that the car so equipped is approaching an obstacle at an unsafe speed and/or is getting too close thereto. The system operation is autonomous and is not monitored by the driver once the system is turned on, it responds only to the presence of an obstacle located ahead of the vehicle. The system detects the differential velocity between the car and the obstacle and determines the distance separating the car from the obstacle which may be fixed or moving in a general direction substantially oriented in the same direction as that followed by the system-equipped vehicle. A signal is generated whenever the combination of differential velocity and separation distance reaches an unsafe level. This signal may be processed so as to emit various types of signals that can be seen, heard and/or be used for taking emergency action such as causing the vehicle brakes to be applied automatically if the driver does not heed the passive signals already emitted. Provisions are built-in to prevent the driver from turning off the system after the emission of a signal has been initiated.

Claims

1. A system for detecting the presence of an obstacle located on the path of a motorized vehicle equipped with such system and for warning the driver of the vehicle that danger of a collision with the obstacle exists, said system comprising:

means for emitting and directing a probing electromagnetic radiation beam ahead of the vehicle;

means for receiving and recording a portion of said beam when reflected off the obstacle, as a reflected signal;

means for analyzing and processing the reflected signal by comparison with the probing radiation beam;

means for determining therefrom the separation distance and the differential velocity between the vehicle and the obstacle;

warning means for indicating the unsafe presence of the obstacle in the vehicle path;

means for focusing said radiation beam in a small solid angle;

means for directing said radiation beam within a specified solid angle having its axis substantially parallel to the vehicle axis and being larger than the focused beam solid angle;

means for causing the beam emitting and focusing means to oscillate about two orthogonal directions located in a plane substantially perpendicular to the beam direction; and

means for adjusting and varying the frequencies of these two oscillations so that they remain out of phase and without harmonics for enabling a point on the beam axis to follow quasi-Lissajous Curve patterns that provide a gradual and continuous coordinated motion of said point along the two oscillation directions, thereby enabling the area thus swept in a scanning fashion by the beam to cover a wide area with a narrow beam of enhanced radiation intensity;

whereby the impact area of the beam on the obstacle provides an enhanced reflection of the beam off the obstacle.

2. The system according to claim 1 wherein the amplitudes of the two oscillations are adjustable, said system further comprising:

means for vibrating a structure, on which the beam emitting means is mounted, in substantially the beam direction;

a combination of spring means and inertial means for causing said vibrations to generate resonance conditions of the beam emitting means about its two axes of oscillation simultaneously; and

means for varying and adjusting the structure vibration frequency so as to vary both resonance conditions concurrently;

whereby the amplitudes of both oscillations vary accordingly and can be adjusted simultaneously.

3. A method of warning the driver of a vehicle equipped with a system for detecting the presence of an obstacle located on the path of a motorized vehicle that a potential collision condition has developed and which must be corrected, said system comprising means for sending and directing probing signals ahead of said vehicle, means for receiving and processing reflections thereof by the obstacle, means for determining from comparison between the emitted signal and the reflected signal the distance separating the vehicle from the obstacle, means for determining the temporal variations of relative velocity of the vehicle with respect to the obstacle, means for determining the actual instantaneous distance separating the vehicle from the obstacle, means for establishing a safety criterion based on a vehicle/obstacle separation distance and the relative velocity thereof, means for warning the driver when the collision condition has developed, means for activating an emergency operation of the vehicle brakes and means for concurrently cutting the delivery rate of the fuel supply to the vehicle engine down to engine idle speed setting, said method comprising the steps of:

measuring the vehicle instantaneous velocity;

computing the instantaneous velocity of the obstacle;

computing the difference between said two velocities;

computing the actual distance separating both vehicle and obstacle at set time intervals;

computing a value of the safe separation distance criterion at the end of each one of said time intervals;

comparing the actual distance between vehicle and obstacle to the criterion value previously just calculated;

generating a warning signal whenever said actual distance becomes smaller than the calculated safe criterion value;

causing the driver to become unequivocally alerted of the existence of a potential collision danger;

generating signals for activating the emergency brake operation and the fuel delivery rate cut-down within a short time after the warning signal has been initiated;

enabling said signals to activate the brake operation and fuel cut-down if no corrective action is taken by the driver during said short time; and

cancelling said signals when corrective actions are taken by the driver during said short time.

4. A method of warning the driver of a vehicle equipped with a system for detecting the presence of an obstacle located on the path of a motorized vehicle that a potential collision condition has developed and which must be corrected, said system comprising means for sending and directing probing signals ahead of said vehicle, means for receiving and processing reflections thereof by the obstacle, means for determining from comparison between the emitted signal and the reflected signal the distance separating the vehicle from the obstacle, means for determining the temporal variations of relative velocity of the vehicle with respect to the obstacle, means for determining the actual instantaneous distance separating the vehicle from the obstacle, means for establishing a safety criterion based on a vehicle/obstacle separation distance and the relative velocity thereof, means for warning the driver when the collision condition has developed, means for preventing the driver from interfering with the system operation after a warning signal has been initiated, said method comprising the steps of:

measuring the vehicle instantaneous velocity;

computing the instantaneous velocity of the obstacle;

computing the difference between said two velocities;

computing the actual distance separating both vehicle and obstacle at set time intervals;

computing a value of the safe separation distance criterion at the end of each one of said time intervals;

comparing the actual distance between vehicle and obstacle to the criterion value previously just calculated;

generating a warning signal whenever said actual distance becomes smaller than the calculated safe criterion value;

causing the driver to become unequivocally alerted of the existence of a potential collision danger;

de-activating an ON/OFF switching means of the system as soon as a warning signal is initiated; and

re-activating said ON/OFF switching means when the collision danger has ceased to exist.