Motion parameter estimating method, angle estimating method and determination method

• US 9,134,407 B2
• Filed: 11/16/2012
• Issued: 09/15/2015
• Est. Priority Date: 07/30/2012
• Status: Active Grant

• Current Assignee: National Chiao Tung University (Government of The Republic of China)
• Original Assignee: National Chiao Tung University (Government of The Republic of China)
• Inventors: Huang, Chung-Jung, Tsai, Tsung-Yu, Lee, Ta-Sung, Dai, Chia-Wei
• Primary Examiner(s): Brainard, Timothy A
• Application Number:
  US13/678,560
• Publication Number:
  US 20140028490A1
• Time in Patent Office: 1,033 Days
• Field of Search: 342/107
• US Class Current: 1/1
• CPC Class Codes: G01S 13/345 using triangular modulation
• CPC Class Codes: G01S 13/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S13/46
• CPC Class Codes: G01S 13/58 Velocity or trajectory determination systems; Sense-of-movement determination systems
• CPC Class Codes: G01S 13/584 adapted for simultaneous range and velocity measurements
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/9321 Velocity regulation, e.g. cruise control
• CPC Class Codes: G01S 2013/93271 in the front of the vehicles

Abstract

A motion parameter estimating method, an angle estimating method and a determination method are provided. The methods are adapted for an electronic device. In the angle estimating method, a first frequency modulation continuous wave signal is first transmitted, and at least one antenna receives a second frequency modulation continuous wave signal resulted by a target reflecting the first frequency modulation continuous wave signal. Multiple motion parameters associated with the target are then obtained according to the first frequency modulation continuous wave signal and the second frequency modulation continuous wave signal. Multiple measured values corresponding to the at least one antenna are obtained according to the motion parameters and configuration parameters of the at least one antenna, respectively. Afterwards, the measured values are substituted into a formula to obtain an estimated angle between a preset direction of the electronic device and the target.

Claims

1. A motion parameter estimating method adapted for a car safety system, the car safety system comprising at least one antenna being arranged as an array, a transmitting antenna and a processor, the method comprising:

transmitting, by the transmitting antenna, a first frequency modulation continuous wave signal;

receiving, by each of the at least one antenna being arranged as the array, a second frequency modulation continuous wave signal resulted by a target reflecting the first frequency modulation continuous wave signal;

obtaining, by the processor, a first formula and a second formula according to the second frequency modulation continuous wave signal received by each of the at least one antenna; and

estimating, by the processor, multiple motion parameters associated with the target according to the first formula and the second formula,

wherein the first formula is

2. The motion parameter estimating method according to claim 1, wherein the first frequency modulation continuous wave signal comprises a first signal and a second signal, the second frequency modulation continuous wave signal comprises a third signal and a fourth signal, and the step of obtaining the first formula and the second formula according to the first frequency modulation continuous wave signal and the second frequency modulation continuous wave signal comprises:

obtaining, by the processor, the first formula according to a relationship between the first signal and the third signal; and

obtaining, by the processor, the second formula according to a relationship between the second signal and the fourth signal.

3. The motion parameter estimating method according to claim 1, wherein the motion parameters comprise the relative distance and the relative speed.

4. The motion parameter estimating method according to claim 1, wherein the frequency bandwidth is determined based on a measuring distance resolution associated with the relative distance.

5. The motion parameter estimating method according to claim 1, wherein the measuring time is determined based on a measuring speed resolution associated with the relative speed.

6. The motion parameter estimating method according to claim 1, wherein the car safety system further comprising an angle estimating unit, and after the step of estimating the motion parameters associated with the target according to the first formula and the second formula, the method further comprises:

obtaining, by the processor, multiple measured values corresponding to the at least one antenna according to the motion parameters and configuration parameters of the at least one antenna, respectively;

obtaining, by the angle estimating unit, a principle argument between any two of the measured values; and

estimating, by the angle estimating unit, an estimated angle between a preset direction of the car safety system and the target according to a linear combination of the principle argument between any two of the measured values.

7. The motion parameter estimating method according to claim 6, wherein, after the step of estimating the estimated angle between the preset direction of the car safety system and the target according to the linear combination of the principle argument between any two of the measured values, the method further comprises:

obtaining, by the angle estimating unit, a parameter yielding the estimated angle to consider a corresponding angle effect; and

estimating, by the angle estimating unit, a set of the estimated angle under the influence of the corresponding angle effect to obtain at least one angle within the scope of a field of view according to the parameter.

8. The motion parameter estimating method according to claim 6, wherein the car safety system further comprising a determination unit, after the step of estimating the estimated angle between the preset direction of the car safety system and the target according to the linear combination of the principle argument between any two of the measured values, the method further comprises:

designing, by the determination unit, a first filter with a zero point outside the scope of the field of view of the car safety system;

designing, by the determination unit, a second filter with a zero point at the estimated angle;

calculating, by the determination unit, a first calculation value of the measured values corresponding to the first filter;

calculating, by the determination unit, a second calculation value of the measured values corresponding to the second filter; and

determining, by the determination unit, reliability of the estimated angle according to a ratio between the first calculation value and the second calculation value.

9. The motion parameter estimating method according to claim 8, wherein the first calculation value is ∥

w₁^Hr∥

₂², where w₁ comprises the coefficients of the first filter, r is a vector comprised of the measured values, (●

)^H is a Hermitian operator, and ∥

●

∥

₂ is a 2-norm operator.

10. The motion parameter estimating method according to claim 8, wherein the second calculation value is ∥

w₂^Hr∥

₂², where w₂ comprises the coefficients of the second filter, r is a vector comprised of the measured values, (●

)^H is a Hermitian operator, and ∥

●

∥

₂ is a 2-norm operator.

11. An angle estimating method adapted for a car safety system, the car safety system comprising at least one antenna being arranged as an array, a transmitting antenna, a processor and an angle estimating unit, the method comprising:

transmitting, by the transmitting antenna, a first frequency modulation continuous wave signal;

receiving, by each of the at least one antenna being arranged as the array, a second frequency modulation continuous wave signal resulted by a target reflecting the first frequency modulation continuous wave signal;

obtaining, by the processor, multiple motion parameters associated with the target according to the first frequency modulation continuous wave signal and the second frequency modulation continuous wave signal;

obtaining, by the processor, multiple measured values corresponding to the at least one antenna according to the motion parameters and configuration parameters of the at least one antenna, respectively;

obtaining, by the angle estimating unit, a principle argument between any two of the measured values; and

estimating, by the angle estimating unit, an estimated angle between a preset direction of the car safety system and the target according to a linear combination of the principle argument between any two of the measured values.

12. The angle estimating method according to claim 11, wherein the step of obtaining multiple motion parameters associated with the target according to the first frequency modulation continuous wave signal and the second frequency modulation continuous wave signal comprises:

obtaining, by the processor, a first formula and a second formula according to the second frequency modulation continuous wave signal received by each of the at least one antenna; and

estimating, by the processor, the multiple motion parameters associated with the target according to the first formula and the second formula,

wherein the first formula is

13. The angle estimating method according to claim 12, wherein the first frequency modulation continuous wave signal comprises a first signal and a second signal, the second frequency modulation continuous wave signal comprises a third signal and a fourth signal, and the step of obtaining the first formula and the second formula according to the first frequency modulation continuous wave signal and the second frequency modulation continuous wave signal comprises:

obtaining, by the processor, the first formula according to a relationship between the first signal and the third signal; and

obtaining, by the processor, the second formula according to a relationship between the second signal and the fourth signal.

14. The angle estimating method according to claim 12, wherein the second formula is:

15. The angle estimating method according to claim 12, wherein the second formula is:

16. The angle estimating method according to claim 12, wherein the motion parameters comprise the relative distance and the relative speed.

17. The angle estimating method according to claim 12, wherein the frequency bandwidth is determined based on a measuring distance resolution associated with the relative distance.

18. The angle estimating method according to claim 12, wherein the measuring time is determined based on a measuring speed resolution associated with the relative speed.

19. The angle estimating method according to claim 11, wherein, after the step of estimating the estimated angle between the preset direction of the car safety system and the target according to the linear combination of the principle argument between any two of the measured values, the method further comprises:

obtaining, by the angle estimating unit, a parameter yielding the estimated angle to consider a corresponding angle effect; and

estimating, by the angle estimating unit, a set of the estimated angle under the influence of the corresponding angle effect to obtain at least one angle within the scope of a field of view according to the parameter.

20. The angle estimating method according to claim 11, wherein the car safety system further comprising a determination unit, after the step of estimating the estimated angle between the preset direction of the car safety system and the target according to the linear combination of the principle argument between any two of the measured values, the method further comprises:

designing, by the determination unit, a first filter with a zero point outside the scope of the field of view of the car safety system;

designing, by the determination unit, a second filter with a zero point at the estimated angle;

calculating, by the determination unit, a first calculation value of the measured values corresponding to the first filter;

calculating, by the determination unit, a second calculation value of the measured values corresponding to the second filter; and

determining, by the determination unit, a reliability of the estimated angle according to a ratio between the first calculation value and the second calculation value.

21. The angle estimating method according to claim 20, wherein the first calculation value is ∥

w₁^Hr∥

₂², where w₁ comprises the coefficients of the first filter, r is a vector comprised of the measured values, (●

)^H is a Hermitian operator, and ∥

●

∥

₂ is a 2-norm operator.

22. The angle estimating method according to claim 20, wherein the second calculation value is ∥

w₂^Hr∥

₂², where w₂ comprises the coefficients of the second filter, r is a vector comprised of the measured values, (●

)^H is a Hermitian operator, and ∥

●

∥

₂ is a 2-norm operator.

23. A determination method adapted for a car safety system, the car safety system comprising at least one antenna being arranged as an array, a transmitting antenna, a processor, an angle estimating unit and a determination unit, the method comprising:

transmitting, by the transmitting antenna, a first frequency modulation continuous wave signal;

receiving, by each of the at least one antenna being arranged as the array, a second frequency modulation continuous wave signal resulted by a target reflecting the first frequency modulation continuous wave signal;

obtaining, by the processor, multiple motion parameters associated with the target according to the first frequency modulation continuous wave signal and the second frequency modulation continuous wave signal;

obtaining, by the processor, multiple measured values corresponding to the at least one antenna according to the motion parameters and configuration parameters of the at least one antenna, respectively; and

estimating, by the angle estimating unit, an estimated angle between a preset direction of the car safety system and the target according to the measured values;

designing, by the determination unit, a first filter with a zero point outside the scope of the field of view of the car safety system;

designing, by the determination unit, a second filter with a zero point at the estimated angle;

calculating, by the determination unit, a first calculation value of the measured values corresponding to the first filter;

calculating, by the determination unit, a second calculation value of the measured values corresponding to the second filter; and

determining, by the determination unit, a reliability of the estimated angle according to a ratio between the first calculation value and the second calculation value.

24. The determination method according to claim 23, wherein the first calculation value is ∥

w₁^Hr∥

₂², where w₁ comprises the coefficients of the first filter, r is a vector comprised of the measured values, (●

)^H is a Hermitian operator, and ∥

●

∥

₂ is a 2-norm operator.

25. The determination method according to claim 23, wherein the second calculation value is ∥

w₂^Hr∥

₂², where w₂ comprises the coefficients of the second filter, r is a vector comprised of the measured values, (●

)^H is a Hermitian operator, and ∥

●

∥

₂ is a 2-norm operator.

26. The determination method according to claim 23, wherein the step of obtaining the multiple motion parameters associated with the target according to the first frequency modulation continuous wave signal and the second frequency modulation continuous wave signal comprises:

obtaining, by the processor, a first formula and a second formula according to the second frequency modulation continuous wave signal received by each of the at least one antenna; and

estimating, by the processor, the multiple motion parameters associated with the target according to the first formula and the second formula,

wherein the first formula is

27. The determination method according to claim 26, wherein the first frequency modulation continuous wave signal comprises a first signal and a second signal, the second frequency modulation continuous wave signal comprises a third signal and a fourth signal, and the step of obtaining the first formula and the second formula according to the first frequency modulation continuous wave signal and the second frequency modulation continuous wave signal comprises:

obtaining, by the processor, the first formula according to a relationship between the first signal and the third signal; and

obtaining, by the processor, the second formula according to a relationship between the second signal and the fourth signal.

28. The determination method according to claim 26, wherein the second formula is

29. The determination method according to claim 26, wherein the second formula is:

30. The determination method according to claim 26, wherein the motion parameters comprise the relative distance and the relative speed.

31. The determination method according to claim 26, wherein the frequency bandwidth is determined based on a measuring distance resolution associated with the relative distance.

32. The determination method according to claim 26, wherein the measuring time is determined based on a measuring speed resolution associated with the relative speed.

33. The determination method according to claim 23, wherein the step of obtaining the estimated angle between a preset direction of the car safety system and the target according to the measured values comprises:

obtaining, by the angle estimating unit, a principle argument between any two of the measured values; and

estimating, by the angle estimating unit, an estimated angle between a preset direction of the car safety system and the target according to a linear combination of the principle argument between any two of the measured values.

34. The determination method according to claim 33, wherein, after the step of estimating the estimated angle between the preset direction of the car safety system and the target according to the linear combination of the principle argument between any two of the measured values, the method further comprises:

obtaining, by the angle estimating unit, a parameter yielding the estimated angle to consider a corresponding angle effect; and

estimating, by the angle estimating unit, a set of the estimated angle under the influence of the corresponding angle effect to obtain at least one angle within the scope of a field of view according to the parameter.