Method and apparatus for reading code using short-range millimeter wave (MMWAVE) radar

• US 10,228,458 B2
• Filed: 03/03/2017
• Issued: 03/12/2019
• Est. Priority Date: 03/03/2016
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Park, Joo-Sung, Bae, Ki-Taek, Kim, Dae-Hyun, Han, Seung-Ku, Yang, Tae-Sik, Chang, Sang-Hyun
• Primary Examiner(s): Bythrow, Peter M
• Application Number:
  US15/449,498
• Publication Number:
  US 20170254898A1
• Time in Patent Office: 739 Days
• CPC Class Codes: G01S 13/584 adapted for simultaneous range and velocity measurements
• CPC Class Codes: G01S 13/753 using frequency selective elements, e.g. resonator
• CPC Class Codes: G01S 13/88 Radar or analogous systems specially adapted for specific applications electromagnetic prospecting or detecting of objects, e.g. near-field detection, G01V3/00
• CPC Class Codes: G01S 13/881 for robotics
• CPC Class Codes: G01S 13/89 for mapping or imaging
• CPC Class Codes: G06K 7/10009 sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
• CPC Class Codes: G06K 7/10326 the antenna being of the very-near field type, e.g. capacitive

Abstract

A code reading method and a radar system using a short-range millimeter wave (mmWave) radar are provided. The method includes transmitting a mmWave radar signal to a target object from a radar system and receiving a reflection wave signal reflected on the target object, extracting reflection signal strengths for a plurality of line codes constituting the target object from the reflection wave signal, compensating for the reflection signal strengths considering a difference in antenna gain between the plurality of line codes as per an antenna radiation pattern of the radar system, forming a radar image using the compensated reflection signal strengths, and reading a binary code from the radar image.

Claims

1. A method for reading a code using a short-range millimeter wave (mmWave) radar, the method comprising:

transmitting a mmWave radar signal to a target object in a radar system and receiving a reflection wave signal reflected on the target object;

extracting reflection signal strengths for a plurality of line codes constituting the target object from the reflection wave signal;

compensating for the reflection signal strengths based on a difference in antenna gain between the plurality of line codes as per an antenna radiation pattern of the radar system;

forming a radar image using the compensated reflection signal strengths; and

reading a binary code from the radar image.

2. The method of claim 1, wherein the compensating for the reflection signal strengths comprises:

identifying a first antenna gain of a line code positioned at a center of the plurality of line codes based on the antenna radiation pattern,

identifying a second antenna gain of a first line code of the plurality of line codes based on the antenna radiation pattern, and

compensating for a reflection signal strength of the first line code by multiplying the reflection signal strength of the first line code by a ratio of the first antenna gain relative to the second antenna gain.

3. The method of claim 1, further comprising compensating for the reflection signal strengths or the compensated reflection signal strengths based on a difference in distance between the line codes.

4. The method of claim 1, wherein the compensating for the reflection signal strengths comprises:

identifying a minimum distance between the radar system and the target object;

calculating a distance between the radar system and a first line code of the plurality of line codes; and

compensating for a reflection signal strength of the first line code by multiplying the reflection signal strength of the first line code by a ratio of the distance to the first line code relative to the minimum distance.

5. The method of claim 1, further comprising calculating times to scan the reflection wave signal, wherein the times are calculated by an equation:

6. The method of claim 1, further comprising calculating times to scan the reflection wave signal, wherein the times are calculated by an equation:

7. The method of claim 1, wherein the forming of the radar image comprises:

calculating a threshold for power strengths corresponding to pixels of the radar image based on a distribution of the power strengths, and

setting power strengths less than the threshold of the power strengths to 0.

8. The method of claim 7, wherein the threshold is calculated by an equation:

Th=P_max−

α

×

E{|P−

E{P}|²}

wherein P is a random variable including reflection signal strengths corresponding to the pixels of the radar image, P_max denotes a maximum value of all pixel values of the radar image, and α

denotes a certain scalability factor.

9. A radar system reading a code using a short-range millimeter wave (mmWave) radar, the radar system comprising:

a transceiver configured to;

transmit a mmWave radar signal to a target object, and

receive a reflection wave signal reflected on the target object; and

a processor configured to;

extract reflection signal strengths for a plurality of line codes constituting the target object from the reflection wave signal,

compensate for the reflection signal strengths based on a difference in antenna gain between the plurality of line codes as per an antenna radiation pattern of the radar system,

form a radar image using the compensated reflection signal strengths, and

read a binary code from the radar image.

10. The radar system of claim 9, wherein the processor is further configured to:

identify a first antenna gain of a line code positioned at a center of the plurality of line codes based on the antenna radiation pattern,

identify a second antenna gain of a first line code of the plurality of line codes based on the antenna radiation pattern, and

compensate for a reflection signal strength of the first line code by multiplying the reflection signal strength of the first line code by a ratio of the first antenna gain relative to the second antenna gain.

11. The radar system of claim 9, wherein the processor is further configured to compensate for the reflection signal strengths or the compensated reflection signal strengths based on a difference in distance between the line codes.

12. The radar system of claim 9, wherein the processor is further configured to:

identify a minimum distance between the radar system and the target object,

calculate a distance between the radar system and a first line code of the plurality of line codes, and

compensate for a reflection signal strength of the first line code by multiplying the reflection signal strength of the first line code by a ratio of the distance to the first line code relative to the minimum distance.

13. The radar system of claim 9, wherein the processor is further configured to calculate times to scan the reflection wave signal by an equation:

14. The radar system of claim 9, wherein the processor is further configured to calculate times to scan the reflection wave signal by an equation:

15. The radar system of claim 9, wherein the processor is further configured to:

calculate a threshold for power strengths corresponding to pixels of the radar image based on a distribution of the power strengths, and

set power strengths less than the threshold of the power strengths to 0.

16. The radar system of claim 15, wherein the threshold is calculated by an equation:

Th=P_max−

α

×

E{|P−

E{P}|²}

wherein P is a random variable including reflection signal strengths corresponding to the pixels of the radar image, P_max denotes a maximum value of all pixel values of the radar image, and α

denotes a certain scalability factor.