Real-time object motion detection system and related method

• US 20050128128A1
• Filed: 07/26/2004
• Published: 06/16/2005
• Est. Priority Date: 12/15/2003
• Status: Abandoned Application

• Current Assignee: Sunplus Technology Co., Ltd
• Original Assignee: Sunplus Technology Co., Ltd
• Inventors: Liao, Tung-Tsai, Lo, Lih-Shang, Hsu, Hung-Ta
• Application Number:
  US10/898,246
• Publication Number:
  US 20050128128A1
• Time in Patent Office: Days
• US Class Current: 342/28
• CPC Class Codes: G01S 11/16 using difference in transit time between electrical and acoustic signals

Abstract

A real-time object motion detection system includes a first object and a second object in relative movement, wherein: the first object sequentially sends a plurality of signal pairs at continuous time points, every signal pair comprising a first signal and a corresponding second signal, and a first propagation speed of the first signal is faster than a second propagation speed of the second signal; and the second object receives the plurality of first signals and second signals, wherein after receiving one first signal, the second object starts to count until receiving the corresponding second signal to obtain a time difference, and then utilizes the time difference to calculate a relative movement distance and speed.

Claims

1. A real-time object motion detection system comprising a first object and a second object in relative movement, wherein:

the first object sequentially sends a plurality of signal pairs at continuous time points, every signal pair comprising a first signal and a corresponding second signal, and a first propagation speed of the first signal is faster than a second propagation speed of the second signal; and

the second object receives the plurality of first signals and second signals, wherein after receiving one first signal, the second object starts to count until receiving the corresponding second signal to obtain a time difference, and then utilizes the time difference to calculate a relative movement distance and speed.

2. The system as claimed in claim 1, wherein the first signal is an electromagnetic wave signal and the second signal is an ultrasonic wave signal.

3. The system as claimed in claim 2, wherein the first object has a first signal transmitting unit and a second signal transmitting unit for respectively sending the first signal and the second signal.

4. The system as claimed in claim 2, wherein the second object has a first signal receiving unit and a second signal receiving unit for respectively receiving the first signal and the second signal.

5. The system as claimed in claim 4, wherein the second object has a timer unit for calculating a time difference between receiving the first signal and receiving the corresponding second signal.

6. The system as claimed in claim 5, wherein the second object has a computing unit utilizing the following equations to obtain the relative movement distance and speed:

L_i=V′

×

t_i,

and

V=(L_i−

L<sub>i−

l</sub>)/Δ

t_i,

where L_i is a distance between the first object and the second object at time t_i, V′

is a propagation speed of the second signal, Δ

t_i is a time difference calculated by the timer unit at time t_i, and V is a relative speed between the first object and the second object.

7. The system as claimed in claim 6, wherein the first object is a fixed object and the second object is a moving object.

8. The system as claimed in claim 7, wherein the fixed object has a display unit and the moving object has a motion information transmission unit for sending the relative movement distance and speed to the fixed object for being displayed on the display unit.

9. The system as claimed in claim 6, wherein the first object is a moving object and the second object is a fixed object.

10. The system as claimed in claim 9, wherein the fixed object has a display unit for displaying the relative movement distance and speed.

11. A moving objecting detection method for detecting relative motion information between a first object and a second object, the method comprising the steps of:

(A) the first object sequentially sending a plurality of signal pairs at continuous time points, every signal pair comprising a first signal and a corresponding second signal, and a first propagation speed of the first signal being faster than a second propagation speed of the second signal;

(B) the second object receiving the plurality of first signals and second signals, wherein after receiving one first signal, the second object starts to count until receiving the corresponding second signal to obtain a time difference; and

(C) the second object utilizing the time difference to calculate the motion information.

12. The method as claimed in claim 11, wherein the motion information includes a relative moving distance and a moving speed.

13. The method as claimed in claim 12, wherein in step (A), the first signal is an electromagnetic wave signal and the second signal is an ultrasonic wave signal.

14. The method as claimed in claim 13, wherein in step (C), the moving distance and the moving speed are obtained by the following equations:

L_i=V′

×

t_i,

and

V=(L_i−

L<sub>i−

1</sub>)/Δ

t_i,

where L_i is a distance between the first object and the second object at time t_i, V′

is a propagation speed of the second signal, Δ

t_i is a time difference calculated by the timing unit at time t_i, and V is a relative speed of the first object and the second object.

15. The method as claimed in claim 14, wherein the first object is a fixed object and the second object is a moving object.

16. The method as claimed in claim 15, further comprises the step of:

(D) the moving object sending the relative movement distance and speed to the fixed object for display.

17. The method as claimed in claim 14, wherein the first object is a moving object and the second object is a fixed object.

18. The method as claimed in claim 17, further comprises the step of:

(E) the fixed object displaying the relative movement distance and speed.