US 4,833,469 A · Obstacle proximity detector for moving vehicles and method for use thereof

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.

Claims4

Dependent claims

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.

8 more elements

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.

9 more elements

Dependencies are inferred from the claim text.

Obstacle proximity detector for moving vehicles and method for use thereof

Life of this patent

Obstacle proximity detector for moving vehicles and method for use thereof

Life of this patent

Abstract

Claims4