Obstacle proximity detector for moving vehicles and method for use thereof

Claim 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.

Claim 2

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.

Claim 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 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.

Claim 5

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.

Claim 6

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.

Claim 7

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.