Car collision prevention apparatus and method using dual processor and automatic sensor switching function

• US 5,594,413 A
• Filed: 12/07/1994
• Issued: 01/14/1997
• Est. Priority Date: 12/27/1993
• Status: Expired due to Term

• Current Assignee: Hyundai AMCO Company Limited (Hyundai Mobis Co., Ltd.)
• Original Assignee: Hyundai Electronics Industries Co. Ltd. (SK Hynix Inc.)
• Inventors: Cho, Jung S., Song, Je S.
• Primary Examiner(s): TONG, NINA C
• Application Number:
  US08/350,554
• Time in Patent Office: 769 Days
• Field of Search: 340/435, 340/436, 340/901, 340/903, 340/904, 342/70, 342/71, 367/909, 367/112, 367/96, 367/97, 367/107, 180/167, 180/168, 180/169, 180/170, 364/460, 364/461, 364/426.04
• US Class Current: 340/435
• CPC Class Codes: G01S 15/89 for mapping or imaging
• CPC Class Codes: G01S 17/86 Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/497 Means for monitoring or calibrating
• CPC Class Codes: Y10S 367/909 Collision avoidance

Abstract

Car collision prevention apparatus and method comprises a slave processor for transmitting and receiving a laser beam or an ultrasonic wave signal to extract distance information between a car and a car in front, and a master processor for comparing the extracted distance information from the slave processor with a safety distance between the car and the front car based on a car speed and performing car accelerating or decelerating and alarm functions in accordance with the compared result. The slave processor comprises a long-distance sensing laser sensor and a short-distance sensing ultrasonic wave sensor disposed in a front side of the car, the long-distance sensing laser sensor consisting of a laser trigger circuit, a laser transmitter and a laser receiver, the short-distance sensing ultrasonic wave sensor consisting of an ultrasonic wave trigger circuit, an ultrasonic wave transmitter and an ultrasonic wave receiver. The long-distance sensing laser sensor is driven in long-distance mode of the car in which the car speed is higher than a reference speed. The short-distance sensing ultrasonic wave sensor is driven in short-distance mode of the car in which the car speed is lower than the reference speed.

Claims

1. A car collision prevention apparatus mountable in a car, comprising:

slave processing means for transmitting and receiving one of a laser beam and an ultrasonic wave signal to extract distance information corresponding to a distance between said car and a car in front of said car; and

master processing means for comparing the distance information from said slave processing means with a predetermined safety distance corresponding to a desired distance between said car and said car in front based on a car speed of said car and performing car accelerating or decelerating and alarm functions in accordance with a compared result, and for initiating one of a long-distance operation mode and a short-distance operation mode based upon said car speed and a reference speed;

said slave processing means including;

laser trigger means for generating a laser trigger pulse signal in response to a drive signal from said master processing means, the laser trigger pulse signal being produced during said long-distance operation mode selected by said master processing means when said car speed is higher than said reference speed;

laser transmission means for emitting said laser beam externally in response to said laser trigger pulse signal from said laser trigger means;

laser reception means for receiving said laser beam after said laser beam is reflected off of said car in front;

ultrasonic wave trigger means for generating an ultrasonic wave trigger pulse signal in response to said drive signal from said master processing means, the ultrasonic wave trigger pulse being produced during said short-distance operation mode selected by said master processing means when said car speed is less than or equal to said reference speed;

ultrasonic wave transmission means for emitting said ultrasonic wave signal externally in response to said ultrasonic wave trigger pulse signal from said ultrasonic wave trigger means and an ultrasonic wave control signal;

ultrasonic wave reception means for receiving said ultrasonic wave signal after said ultrasonic wave signal is reflected off of said car in front;

counting means for generating time data by starting a counting operation in response to the laser trigger pulse signal from said laser trigger means or the ultrasonic wave trigger pulse signal from said ultrasonic wave trigger means and stopping the counting operation in response to an output signal from a respective one of said laser reception means or said ultrasonic wave reception means; and

distance information transmission means for converting said time data from said counting means into said distance information and transmitting said distance information to said master processing means; and

said ultrasonic wave reception means including;

an ultrasonic wave receiving sensor for receiving the ultrasonic wave signal emitted from said ultrasonic wave transmission means and reflected off of said car in front;

a first amplifier for amplifying said output signal from said ultrasonic wave receiving sensor to produce an amplified output signal;

a band pass filter for band pass filtering said amplified output signal from said first amplifier to remove a noise component therefrom;

a second amplifier for amplifying an output signal from said band pass filter;

a detector for detecting an output signal from said second amplifier and outputting a detected signal in a digital form;

a comparator for comparing said detected signal from said detector with said ultrasonic wave control signal from said ultrasonic wave transmission means;

a reference time operating circuit for generating a reference time period signal in response to the ultrasonic wave control signal from said ultrasonic wave transmission means;

a time comparator for comparing an output signal from said comparator with the reference time period signal from said reference time operating circuit; and

a signal adjustment unit for adjusting an output signal from said time comparator to permit processing by said distance information transmission means.

2. A car collision prevention method for use in a car to avoid collision with a car in front of said car, the method comprising the steps of:

(a) transmitting and receiving one of a laser beam and an ultrasonic wave signal during a respective one of long-distance and short-distance operation modes and extracting distance information corresponding to a distance between said car and said car in front based on reception of said one of said laser beam and said ultrasonic wave signal, said transmitting and receiving step and said extracting step being effected by a slave processor;

(b) comparing the distance information from said slave processor with a predetermined safety distance corresponding to a desired distance between said car and said car in front based on a car speed of said car and performing car accelerating or decelerating and alarm functions in accordance with a compared results, and initiating one of the long-distance operation mode and the short-distance operation mode based upon said car speed and a reference speed, said comparing, performing and initiating steps being effected by a master processor;

said step (a) including the steps of;

(a-1) initializing a system and performing a self-diagnostic function;

(a-2) checking whether the system is normal;

(a-3) stopping an operation if it is determined at said step (a-2) that the system is not normal;

(a-4) calculating said car speed if it is determined at said step (a-2) that the system is normal and discriminating whether the calculated car speed is higher than the reference speed;

(a-5) driving a laser and monitoring a laser sensor if it is discriminated at said step (a-4) that the calculated car speed is higher than the reference speed and driving an ultrasonic wave transmitter and monitoring an ultrasonic wave sensor if it is discriminated at said step (a-4) that the calculated car speed is lower than the reference speed;

(a-6) obtaining the distance information using said laser sensor or said ultrasonic wave sensor monitored at said step (a-5) and transmitting the distance information to said master processor; and

(a-7) checking whether the transmission of the distance information is completed, standing by until a current loop time elapses if it is checked that the transmission of the distance information is completed, programming a subsequent loop time if the current loop time has elapsed and clearing a counter.

3. A car collision prevention method for use in a car to avoid collision with a nearby car, the method comprising the steps of:

(a) transmitting and receiving one of a laser beam and an ultrasonic wave signal during a respective one of long-distance and short-distance operation modes and extracting distance information corresponding to a distance between said car and said nearby car based on reception of said one of said laser beam and said ultrasonic wave signal;

said transmitting and receiving step and said extracting step being effected by a slave processor;

(b) comparing the distance information from said slave processor with a predetermined safety distance corresponding to a desired distance between said car and said nearby car based on a car speed of said car and performing car accelerating or decelerating and alarm functions in accordance with a compared result, and initiating one of the long-distance operation mode and the short-distance operation mode based upon said car speed and a reference speed;

said comparing, performing and initiating steps being effected by a master processor; and

said step (b) including the steps of;

(b-1) initializing a system and performing a self-diagnostic function to check whether the system is normal;

(b-2) programming a loop time if it is determined at said step (b-1) that the system is normal and reading the distance information from said slave processor;

(b-3) calculating the car speed and calculating the safety distance between the car and the nearby car based on the calculated car speed;

(b-4) comparing the safety distance calculated at said step (b-3) with the distance information read at said step (b-2) to discriminate whether a front alarm is required;

(b-5) operating the front alarm if it is discriminated at said step (b-4) that the front alarm is required and reading rear distance data from said slave processor if it is discriminated at said step (b-4) that the front alarm is not required;

(b-6) discriminating whether the rear distance data read at said step (b-5) is greater than a reference value, to check whether a rear alarm is required, operating the rear alarm if it is determined that the rear alarm is required as the rear distance data is smaller than the reference value and checking whether a left or right alarm is required, if it is determined that the rear alarm is not required where the rear distance data is greater than the reference value;

(b-7) operating the left or right alarm if it is determined at said step (b-6) that the left or right alarm is required; and

(b-8) standing by until the loop time elapses, if it is determined at said step (b-6) that the left or right alarm is not required, and, if the loop time has elapsed, programming a subsequent loop time to perform a subsequent loop.

4. A car collision prevention apparatus mountable in a car, comprising:

slave processing means for transmitting and receiving one of a laser beam and an ultrasonic wave signal to extract distance information corresponding to a distance between said car and a car in front of said car;

master processing means for comparing the distance information from said slave processing means with a predetermined safety distance corresponding to a desired distance between said car and said car in front based on a car speed of said car and performing car accelerating or decelerating and alarm functions in accordance with a compared result, and for initiating one of a long-distance operation mode and a short-distance operation mode based upon said car speed and a reference speed;

said slave processing means including;

laser transmission means for transmitting said laser beam in response to a drive signal from said master processing means, the laser beam being produced during said long-distance operation mode selected by said master processing means when said car speed is higher than said reference speed;

laser reception means for receiving said laser beam after said laser beam is reflected off of said car in front;

ultrasonic wave transmission means for transmitting said ultrasonic wave signal in response to said drive signal from said master processing means and an ultrasonic wave control signal, said ultrasonic wave signal being transmitted during said short-distance operation mode selected by said master processing means when said car speed is less than or equal to said reference speed;

ultrasonic wave reception means for receiving said ultrasonic wave signal after said ultrasonic wave signal is reflected off of said car in front;

counting means for generating time data by starting a counting operation in response to the transmission of said laser beam or the transmission of said ultrasonic wave signal and stopping the counting operation in response to an output signal from a respective one of said laser reception means or said ultrasonic wave reception means; and

distance information transmission means for determining said distance information based on delayed reception of said one of said laser beam and said ultrasonic wave signal and for transmitting said distance information to said master processing means; and

said ultrasonic wave reception means including;

an ultrasonic wave receiving sensor for receiving the ultrasonic wave signal emitted from said ultrasonic wave transmission means and reflected off of said car in front;

a first amplifier for amplifying an output signal from said ultrasonic wave receiving sensor to produce an amplified output signal;

a band pass filter for band pass filtering said amplified output signal from said first amplifier to remove a noise component therefrom;

a second amplifier for amplifying an output signal from said band pass filter;

a detector for detecting an output signal from said second amplifier and outputting a detected signal in a digital form;

a comparator for comparing said detected signal from said detector with said ultrasonic wave control signal from said ultrasonic wave transmission means;

a reference time operating circuit for generating a reference time period signal in response to the ultrasonic wave control signal from said ultrasonic wave transmission means;

a time comparator for comparing an output signal form said comparator with the reference time period signal from said reference time operating circuit; and

a signal adjustment unit for adjusting an output signal from said time comparator to produce said output signal from said ultrasonic wave reception means to permit processing by said distance information transmission means.