REAR WARNING SYSTEM OF A VEHICLE FOR DETECTING AND DISCRIMINATING OBSTACLES REQUIRED TO BE WARNED OR NOT TO BE WARNED AND EXECUTING FREELY TUNING WORK BY USING AN EMBEDDED PROGRAMMABLE REFERENCE VOLTAGE MODULE

摘要

PURPOSE: A rear warning system for a vehicle is provided to execute freely tuning work more than an existing warning system using a built-out comparator, to shorten tuning time, and to improve obstacle detection efficiency by doubly filtering a reflected signal with same frequency band. CONSTITUTION: A rear warning system for a vehicle is composed of a plurality of supersonic sensors(10) mounted at a rear bumper of the vehicle and composed of a transmitting unit for radiating supersonic waves by a driving signal and a receiving unit for receiving a signal reflected from an object; a driving circuit(20) for transmitting the driving signal to each supersonic sensor; a reflective driving circuit(30) operated together with the driving circuit to collect reflected signals from each supersonic sensor; a first band filter(40a) for filtrating the reflected signals of the supersonic sensors collected by the reflective driving circuit into specific frequency band; a second band filter(40b) for filtrating secondarily the reflected signals with frequency band same as the specific frequency band of the first band filter; an amplifying circuit(50) for amplifying the reflected signals passing through the second band filter at specific amplification rate; a detection circuit(60) for detecting the reflected signals passing through the amplifying circuit; and a central processing unit(80a) for outputting a driving signal operating the supersonic sensors, controlling operations of the driving circuit and the reflective driving circuit, comparing a voltage value of the reflected signal passing through the detection circuit with a reference voltage value of a programmable reference voltage module(70a), and then outputting a warning signal to a warning unit(81) if the voltage value of the reflected signal is larger than the reference voltage value of the programmable reference voltage module. The central processing unit comprises a reference voltage regulating register outputting various program constants for setting various reference voltage values with corresponding to operation time of the supersonic sensor and a timer and the programmable reference voltage module outputting various reference voltage values with corresponding to the program constants output from the reference regulating register.