Method and system for range measurement

• US 7,414,705 B2
• Filed: 11/21/2006
• Issued: 08/19/2008
• Est. Priority Date: 11/29/2005
• Status: Expired due to Fees

• Current Assignee: Navisense
• Original Assignee: Navisense
• Inventors: Boillot, Marc Andre
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): Brainard, Timothy A
• Application Number:
  US11/562,410
• Publication Number:
  US 20070121097A1
• Time in Patent Office: 637 Days
• Field of Search: 356/28, 356/5.01, 356/5.1, 356/5.09
• US Class Current: 356/5.01
• CPC Class Codes: G01S 15/104 wherein the transmitted pulses use a frequency- or phase-modulated carrier wave
• CPC Class Codes: G01S 15/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S15/46
• CPC Class Codes: G01S 15/50 Systems of measurement, based on relative movement of the target
• CPC Class Codes: G01S 15/88 Sonar systems specially adapted for specific applications seismic or acoustic prospecting or detecting G01V1/00
• CPC Class Codes: G06F 3/0304 Detection arrangements using opto-electronic means constructional details of pointing devices not related to the detection arrangement using opto-electronic means G06F3/033; optical digitisers G06F3/042
• CPC Class Codes: G06F 3/0428 by sensing at the edges of the touch surface the interruption of optical paths, e.g. an illumination plane, parallel to the touch surface which may be virtual sensing beam interruptions in a planar beam grid of an optical touch-screen G06F3/0421

Abstract

A method (200) and system (220) for range detection is provided. The system can include a sensing unit (110) for detecting a location and movement of a first object (401), and a processor (107) for providing a measure of the movement. The processor can convert the measure to a coordinate signal for moving a second object (124) in accordance with a location and movement of the first object. The system can include a pulse shaper (109) for producing a pulse shaped signal (167) and a phase detector (101) for identifying a movement from a reflected signal (166). A portion of the pulse shaped signal can be a frequency modulated region (312), a constant frequency region (316), or a chirp region (324). In one arrangement, the pulse shaper can be a cascade of all-pass filters (515) for providing phase dispersion.

Claims

1. A sensing device for providing touchless control comprising:

a pulse shaper for producing a pulse shaped signal, the pulse shaped signal intended for reflecting off a first object to produce a reflected signal, wherein at least one portion of the pulse shaped signal is at least one among a frequency modulated region, constant frequency region, phase modulated region, and a chirp region;

a phase detector for receiving and identifying a relative phase of the reflected signal with respect to a previously received reflected signal, and

a processor operatively coupled to the pulse shaper for receiving the reflected signal, tracking a location and a movement of the first object from an estimated arrival time of the reflected signal and the relative phase, and providing control to a second object that is a user interface control in accordance with the location and the movement of the first object,

wherein the processor estimates the location of the first object from a frequency modulated region of the reflected signal, and a velocity of the first object from the relative phase from the constant frequency region of the reflected signal.

2. The sensing device of claim 1, wherein the pulse shaper is a physical transducer element that emits the pulse shaped signal with a frequency modulation portion and an amplitude modulation portion.

3. The sensing device for claim 1, wherein the pulse shaper includes at least one all-pass filter as a phase warping element for providing phase dispersion in the pulse shaped signal.

4. The method for claim 1, wherein the pulse shaper concentrates an energy of the pulse signal within a narrow region of the pulsed shaped signal to produce a symmetric peak in the pulse shaped signal.

5. The method for claim 1, wherein the pulse shaper transmits the pulsed shaped signal as a continuous transmission of a frequency modulated signal, a phase modulated signal, or an amplitude modulated signal.

6. An ultrasonic sensor device for short-range detection, comprising:

a pulse shaper for producing an ultrasonic chirp signal with an amplitude modulated region and a frequency modulated region;

at least one transmit sensor operatively coupled to the pulse shaper for transmitting the ultrasonic chirp signal, the ultrasonic chirp signal intended for reflecting off a finger to produce a reflected chirp signal;

at least one receive sensor for receiving the reflected chirp signal;

a phase detector for identifying a relative phase of the reflected chirp signal from the frequency modulated region with respect to a frequency modulated region of a previously received reflected signal, and

a processor coupled to the phase detector and the receive sensor for identifying a location of the finger from an arrival time of the amplitude modulated region of the reflected chirp signal and a movement of the finger from the relative phase of the frequency modulated region, and providing control to a user interface control in accordance with the location and the movement of the finger.

7. A method for touchless control, the method comprising the steps of:

shaping a pulse signal to produce a pulse shaped signal;

transmitting the pulse shaped signal, the pulse shaped signal reflecting off a first object to produce a reflected signal;

receiving the reflected signal;

identifying a relative phase of the reflected signal with respect to a previously received reflected signal;

estimating a location of the first object from a frequency modulated region of the reflected signal,

estimating a velocity of the first object from the relative phase from the constant frequency region of the reflected signal; and

providing control to a second object that is a user interface control in accordance with the location and the movement of the first object,

wherein the shaping uses a combination of amplitude modulation, frequency modulation, and phase modulation.