Car reversal radar that automatically modifies the sensor scanning range and method of the same

• US 7,567,168 B2
• Filed: 10/24/2006
• Issued: 07/28/2009
• Est. Priority Date: 10/24/2006
• Status: Active Grant

• Current Assignee: Coligen Corp.
• Original Assignee: Shih-Hsiung Li
• Inventors: Li, Shih-Hsiung
• Primary Examiner(s): Goins; Davetta W
• Assistant Examiner(s): LAU, HOI CHING
• Application Number:
  US11/585,093
• Publication Number:
  US 20080094193A1
• Time in Patent Office: 1,008 Days
• Field of Search: 340/435, 340/436, 340/431, 340/932.2, 340/903, 701/1, 701/45, 701/150, 701/301, 701/36, 342/69, 342/70, 342/27, 342/89, 342/85, 342/118, 367/99, 367/112, 307/10.1
• US Class Current: 340/435
• CPC Class Codes: G01S 15/931 of land vehicles
• CPC Class Codes: G08G 1/16 Anti-collision systems road vehicle drive control systems for predicting or avoiding probable or impending collision otherwise than by control of a particular sub-unit B60W30/08
• CPC Class Codes: G08G 1/168 Driving aids for parking, e.g. acoustic or visual feedback on parking space

Abstract

A car reversal radar automatically modifies the sensor scanning range and the method of the same. The car reversal radar includes a central processing unit that has predetermined compensation value and threshold distance. When the car reversal radar starts, its surrounding environment is recorded into an initial detecting value. The initial detecting value is compared with a subsequent detecting value recorded for the environment when the car is being backed. When the subsequent detecting value is greater than the sum of the initial detecting value and the compensation value, the distance between an obstacle and the ultrasonic sensor of the car is compared with the threshold distance. If the former is greater than the latter, the compensation value is increased. Therefore, the obstacle has to even closer to the ultrasonic sensor to reduce the sensitivity of the ultrasonic sensors at the tail and to prevent incorrect actions.

Claims

1. A method of automatically modifying an ultrasonic sensor scanning range of a car reversal radar, comprising the steps of:

predetermining compensation values for ultrasonic sensors and a threshold distance;

when the car reversal radar starts, sending out ultrasonic waves from the ultrasonic sensors to detect any obstacle and obtaining initial sensing results from the ultrasonic sensors;

storing each of the initial sensing results as an initial sensing value;

continuously detecting obstacles using the ultrasonic sensors to obtain a plurality of subsequent sensing results from the ultrasonic sensors;

storing each of the subsequent sensing results as a subsequent sensing value;

when the subsequent sensing value of any of the ultrasonic sensors is greater than a corresponding sum of the initial sensing value and compensation value, determining that an obstacle is detected and computing an actual distance between the obstacle and the ultrasonic sensor; and

if the actual distance between the obstacle and one of the ultrasonic sensors mounted on both sides at the back of the car is greater than the threshold distance, increasing the compensation value of the corresponding one of the ultrasonic sensors that detects the actual distance being greater than the threshold distance to reduce the sensitivity of the corresponding one of the ultrasonic sensors.

2. A car reversal radar, comprising:

a CPU;

a memory unit connected to the CPU;

an ultrasonic wave transceiving module that is used to emit and receive ultrasonic waves, the ultrasonic wave transceiving module including multiple sensor drivers and ultrasonic sensors;

wherein each of the ultrasonic sensors is coupled to the CPU via one of the sensor drivers and controlled by the CPU to send out ultrasonic waves;

a signal amplifying module being connected between the CPU and the ultrasonic transceiving module for amplifying reflected signals received by the ultrasonic sensors and then sending them to the CPU; and

a warning module connected to the CPU for generating a warning when an obstacle is detected;

wherein the memory unit stores compensation values for the ultrasonic sensors and a threshold distance;

when the car reversal radar is started, the ultrasonic sensors send out ultrasonic waves to detect any obstacle and obtain initial sensing results;

the memory unit stores each of the initial sensing results as an initial sensing value;

the ultrasonic sensors then continuously detect obstacles to obtain subsequent sensing results;

the memory stores each of the subsequent sensing results as a subsequent sensing value;

when the subsequent sensing value of any of the ultrasonic sensors is greater than a corresponding sum of the initial sensing value and the compensation value, an obstacle is detected, and the CPU computes an actual distance between the obstacle and the ultrasonic sensor; and

if the actual distance between the obstacle and one of the ultrasonic sensors mounted on both sides at the back of the car is greater than the threshold distance, increasing the compensation value of the corresponding one ultrasonic sensor that detects the actual distance being greater than the threshold distance to reduce the sensitivity of the corresponding one ultrasonic sensor.

3. The car reversal radar of claim 2, wherein the ultrasonic transceiving module further includes a multiplexer connected to the CPU, the sensor drivers, and the signal amplifying module,

wherein the multiplexer selects the reflected signals received by the ultrasonic sensors to be amplified by the signal amplifying module.

4. The car reversal radar of claim 2, wherein the warning module includes

a display unit connected to the CPU via a display driver;

and

a sound warning unit including a buzzer connected to the CPU via a sound driving circuit.

5. The car reversal radar of claim 2, wherein the memory unit is built in the CPU.

6. The car reversal radar of claim 3, wherein the memory unit is built in the CPU.

7. The car reversal radar of claim 4, wherein the memory unit is built in the CPU.

8. The car reversal radar of claim 5, wherein the CPU is an ATMega8 microprocessor.

9. The car reversal radar of claim 6, wherein the CPU is an ATMega8 microprocessor.

10. The car reversal radar of claim 7, wherein the CPU is an ATMega8 microprocessor.