Apparatus for the recognition of the presence of an object in space

• US 8,059,263 B2
• Filed: 07/08/2009
• Issued: 11/15/2011
• Est. Priority Date: 07/09/2008
• Status: Active Grant

• Current Assignee: Sick AG (Sick)
• Original Assignee: Sick AG (Sick)
• Inventors: Rothenberger, Bernd, Haberer, Manfred
• Primary Examiner(s): Tarcza; Thomas
• Assistant Examiner(s): Bedard; Antoine J
• Application Number:
  US12/458,354
• Publication Number:
  US 20100007870A1
• Time in Patent Office: 860 Days
• Field of Search: 356/5.01
• US Class Current: 356/5.01
• CPC Class Codes: G01S 17/04 Systems determining the presence of a target
• CPC Class Codes: G01S 17/10 using transmission of interrupted, pulse-modulated waves determination of distance by phase measurements G01S17/32
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 2007/4975 of sensor obstruction by, e.g. dirt- or ice-coating, e.g. by reflection measurement on front-screen
• CPC Class Codes: G01S 7/4811 common to transmitter and receiver
• CPC Class Codes: G01S 7/497 Means for monitoring or calibrating
• CPC Class Codes: G01S 7/4972 Alignment of sensor
• CPC Class Codes: G02B 26/105 with one or more pivoting mirrors or galvano-mirrors G02B26/101 takes precedence

Abstract

An apparatus for the recognition an object in space in accordance with the pulsed time-of-flight principle. The apparatus has a pulsed laser and a photoreceiver arrangement which receives the light pulses reflected back from the object present in the space. The apparatus has a first light deflection apparatus which outputs a first angular position signal representative of its instantaneous angular position to the evaluation circuit, wherein the first light deflection apparatus is arranged rotatably or pivotably about a first axis of rotation and is made for the transmission of light pulses following one another at changing angles in a first plane, wherein a second light deflection apparatus is arranged between the first light deflection apparatus. The apparatus outputs a second angular position signal representative of its instantaneous angular position to the evaluation circuit which has a deflection plate which is arranged rotatably or pivotably about a second axis of rotation.

Claims

1. An apparatus (10) for the recognition of the presence of an object (110) in space (100) in accordance with the pulsed time-of-flight method having a pulsed laser (20) which transmits light pulses into the space (100) in a controlled manner, having a photoreceiver arrangement (40) which receives the light pulses reflected back from the object (110) present in the space, having an evaluation circuit which determines a distance signal characteristic for the distance (d) of the object (110) from the pulsed laser (20) from the time (t) between the transmission and the reception of a light pulse, and having a first light deflection apparatus (50) which outputs a first angular position signal representative of its instantaneous angular position to the evaluation circuit, wherein the first light deflection apparatus (50) is arranged rotatably or pivotably about a first axis of rotation (90) and is made for the transmission of light pulses following one another at changing angles in a first plane (95), characterized in that

a second light deflection apparatus (60) is arranged between the first light deflection apparatus (50) and an energy supply of the first light deflection apparatus (50) which outputs a second angular position signal representative of its instantaneous angular position to the evaluation circuit and which has a deflection plate (62) which is arranged rotatably or pivotably about a second axis of rotation (92) and which is made for the changing of the angular position of the first plane (95), with the evaluation circuit determining the position of the object (110) in the space (100) from the first angular position signal, the second angular position signal and the distance signal, and with the apparatus (10) being arranged in a housing (140) having a window (142).

2. An apparatus in accordance with claim 1, characterized in that the first light deflection apparatus (50) is arranged between the space (100) and the pulsed laser (20) and has a deflection mirror (52) which is arranged rotatably or pivotably about the first axis of rotation (90) and which is made for the transmission of light pulses following one another at changing angles in a first plane (95) and for the guidance of the light pulses reflected back to the photoreceiver arrangement (40).

3. An apparatus in accordance with claim 1, characterized in that the first and the second axes of rotation (90, 92) are arranged perpendicular to one another.

4. An apparatus in accordance with claim 1, characterized in that the first light deflection apparatus (50) is arranged on the deflection plate (62).

5. An apparatus in accordance with claim 1, characterized in that the pulsed laser (20) and/or the photoreceiver arrangement (40) is/are fixedly arranged on the deflection plate (62).

6. An apparatus in accordance with claim 1, characterized in that the deflection mirror (52) and/or the deflection plate (62) has/have a deflection angle of more than 180°

, preferably of more than 270°

, in particular of 360°

.

7. An apparatus in accordance with claim 1, characterized in that the deflection mirror (52) is made as a rotating mirror and/or the deflection plate (62) is made as a turntable.

8. An apparatus in accordance with claim 1, characterized in that the energy transmission between moving and non-moving components of the apparatus (10), in particular the energy transmission from the energy supply of the first light deflection apparatus (50) to the first light deflection apparatus (50), takes place in a contactless manner, in particular inductively.

9. An apparatus in accordance with claim 1, characterized in that the data transmission between moving and non-moving components of the apparatus (10) takes place in a contactless manner, in particular inductively, capacitively or optically.

10. An apparatus in accordance with claim 1, characterized in that the apparatus (10) is made as a safe apparatus;

is in particular made in accordance with the standards EN 61496, EN 61508 or EN 954.

11. An apparatus in accordance with claim 1, characterized in that at least one light-reflecting or light-scattering test body (120) is arranged such that the light pulses transmitted by the pulsed laser are incident on the test body (120) at defined angular positions of the first and/or second light deflection apparatus (50, 60) and are reflected back into the photoreceiver arrangement (40).

12. An apparatus in accordance with claim 1, characterized in that the first light deflection apparatus (50), in particular the deflection mirror (52), has a first rotational frequency of approximately 20 to 100 Hz, in particular of approximately 50 Hz, with preferably the first rotational frequency being variably adjustable;

and/or in that the second light deflection apparatus, in particular the deflection plate (62) has a second rotational frequency of approximately 1 to 15 Hz, in particular of approximately 5 Hz, with the second rotational frequency preferably being variably adjustable.

13. An apparatus in accordance with claim 1, characterized in that the window (142) is made at least partly as a part of a spherical surface, in particular as a hemisphere.

14. An apparatus in accordance with claim 1, characterized in that a comparator is provided in which the signals of the light pulses reflected back by the window (142) are compared with a reference signal, with the reference signal being the signal of the light pulse reflected back at a clean window (142).