Hybrid compact sensing apparatus for adaptive robotic processes

• US 7,283,892 B1
• Filed: 04/03/2007
• Issued: 10/16/2007
• Est. Priority Date: 04/03/2006
• Status: Active Grant

• Current Assignee: Servo-Robot Inc.
• Original Assignee: Servo-Robot Inc.
• Inventors: Boillot, Jean-Paul, Fontaine, Jean-Claude
• Primary Examiner(s): Black; Thomas
• Assistant Examiner(s): Marc; McDieunel
• Application Number:
  US11/730,694
• Publication Number:
  US 20070233322A1
• Time in Patent Office: 196 Days
• Field of Search: 700/259, 318/568.1, 318/568.11, 318/568.12, 318/568.18, 318/568.2, 901/41, 901/42, 219/121.61, 219/121.62, 219/121.63, 219/121.64, 219/121.82, 219/121.83
• US Class Current: 700/245
• CPC Class Codes: G01S 15/08 Systems for measuring distance only indirect measurement G01S15/46
• CPC Class Codes: G01S 17/08 for measuring distance only indirect measurement G01S17/46; active triangulation systems G01S17/48
• CPC Class Codes: G01S 17/46 Indirect determination of position data

Abstract

A hybrid compact sensing apparatus for generating signals usable for guiding a process robot as a function of an object detected in a scene. The apparatus comprises a laser light generator, two optical sensors, one or more ultrasound sensors, and a control unit, all integrated in a same housing. The laser light generator and the optical sensors form a detection arrangement having a limited detection range compared to that of the ultrasound sensors. The control unit has a processing circuit monitoring the distance of the object measured by the ultrasound sensors, and triggering on the laser light generator and triggering use of the depth profile signals produced by the optical sensors among the signals usable for guiding the process robot when the distance measured by the ultrasound sensors falls within the limited detection range. Integration of an audio and video sensing unit to the apparatus enables remote monitoring.

Claims

1. A hybrid compact sensing apparatus for generating signals usable for guiding a process robot as a function of an object detected in a scene, comprising:

a housing attachable to the process robot and having a component mounting structure;

a laser light generator mounted onto the component mounting structure of the housing and having a laser light output through the housing for controllable projection of at least two planes of laser light in a predetermined pattern towards the scene;

two optical sensors mounted onto the component mounting structure of the housing and having optical inputs through the housing for detection of respective laser lines produced by intersection of the laser light with the object, and signal outputs producing depth profile signals indicative of a geometry of the object as a function of the detected laser lines, the laser light generator and the two optical sensors forming a detection arrangement having a first detection range limited by a field of view of the optical sensors and an effective range of the laser light generator;

at least one ultrasound sensor mounted onto the component mounting structure of the housing and having an ultrasound transducer element through the housing for controllable emission of at least one ultrasound signal towards the scene within a second detection range substantially exceeding the first detection range and for reception of an echo signal returned by the object, and a signal output producing a measurement signal indicative of a distance of the object as a function of the detected echo signal; and

a control unit connected to the laser light generator, the two optical sensors and the at least one ultrasound sensor, the control unit having a processing means monitoring the distance measured by the at least one ultrasound sensor as indicated by the measurement signal, providing the measurement signal as the signals usable for guiding the process robot, and triggering on the laser light generator and triggering use of the depth profile signals produced by the optical sensors among the signals usable for guiding the process robot when the distance measured by the at least one ultrasound sensor falls within the first detection range.

2. The hybrid compact sensing apparatus according to claim 1, wherein the control unit comprises a circuit board mounted onto the component mounting structure of the housing, the processing means being mounted onto the circuit board.

3. The hybrid compact sensing apparatus according to claim 2, wherein:

the component mounting structure comprises a mounting plate dividing the housing into rear and front opposite housing spaces;

the two optical sensors are provided with respective focusing lenses directed toward the scene and having field of views covering the first detection range;

the two optical sensors and the circuit board extend in the rear housing space; and

the laser light generator, the at least one ultrasound sensor, and the focusing lens extend in the front housing space.

4. The hybrid compact sensing apparatus according to claim 1, further comprising a speaker circuit mounted onto the component mounting structure of the housing and connected to the control unit, wherein the processing means of the control unit drives the speaker circuit so that a remotely audible audio signal is produced as a function the distance measured by the at least one ultrasound sensor as indicated by the measurement signal.

5. The hybrid compact sensing apparatus according to claim 4, wherein:

the at least one of the ultrasound sensor comprises multiple ultrasound sensors; and

the remotely audible audio signal comprises a different tone for each one of the ultrasound sensors, modulated with frequency inversely proportional to the distance measured by a corresponding one of the ultrasound sensors.

6. The hybrid compact sensing apparatus according to claim 1, wherein the housing is provided with a hollow shaft assembly attachable to the process robot and providing an inner wiring passage forming a gateway for power and data communication between the process robot and the hybrid compact sensing apparatus.

7. The hybrid compact sensing apparatus according to claim 6, wherein the at least two planes of laser light have an axis coincident with an axis of the hollow shaft assembly.

8. The hybrid compact sensing apparatus according to claim 1, wherein the at least two planes of laser light comprise two planes of laser light perpendicular with respect to each other.

9. The hybrid compact sensing apparatus according to claim 1, further comprising a video sensing module mounted onto the component mounting structure of the housing and having a field of view directed on the scene for producing a video image signal of the scene, and at least one light source mounted onto the component mounting structure of the housing for illumination of the scene to be captured by the video sensing module.

10. The hybrid compact sensing apparatus according to claim 9, wherein the at least one light source comprises light emitting diodes.

11. The hybrid compact sensing apparatus according to claim 9, further comprising a microphone mounted onto the component mounting structure of the housing, for detecting ambient sound.

12. The hybrid compact sensing apparatus according to claim 1, wherein:

the measurement signal produced by the at least one ultrasound sensor is in analog form;

the depth profile signals produced by the optical sensors are in a form of digital video signals; and

the processing means of the control unit converts the measurement signal into a digital value, compares the digital value to a threshold value, controls operation of the laser light generator in response to a comparison result between the digital and threshold values, receives the video signals from the optical sensors, processes the video signals, controls operation of the optical sensors and the at least one ultrasound sensor, and communicates with the process robot for process control.

13. The hybrid compact sensing apparatus according to claim 1, wherein the housing has a cover plate having multiple orifices for the laser light output of the laser light generator, the optical inputs of the optical sensors and the ultrasound transducer element of the at least one ultrasound sensor.

14. The hybrid compact sensing apparatus according to claim 1, wherein the laser light output, the optical inputs and the ultrasound transducer element substantially extend in a same plane.

15. The hybrid compact sensing apparatus according to claim 1, wherein the processing means of the control unit comprises an autocalibration means establishing a common reference for the at least one ultrasound sensor and the optical sensors.

16. The hybrid compact sensing apparatus according to claim 15, wherein the autocalibration means is effected by determining a relation between a coordinate system of the at least one ultrasound sensor and a coordinate system of the optical sensors from distance measurements taken by the at least one of the ultrasound sensor and the optical sensors for a target object positioned in the scene within the first detection range.

17. The hybrid compact sensing apparatus according to claim 16, wherein the target object has a flat surface positioned perpendicular to a common axis of the planes of laser light.

18. The hybrid compact sensing apparatus according to claim 1, wherein the laser light generator, the two optical sensors and the at least one ultrasound sensor are all positioned in a symmetrical arrangement with respect to a central transverse axis of the housing.

19. A two-stage process for guiding a process robot as a function of an object detected in a scene, comprising the steps of:

providing the process robot with a sensing apparatus comprising a laser light generator, two optical sensors, and at least one ultrasound sensor, all integrated in a same housing, the laser light generator and the two optical sensors forming a detection arrangement having a first detection range towards the scene limited by a field of view of the optical sensors and an effective range of the laser light generator, the at least one ultrasound sensor having a second detection range towards the scene substantially exceeding the first detection range;

monitoring the scene with the at least one ultrasound sensor to detect presence and motion of the object and generating ultrasonic sensor data representative of a position of the detected object in the scene;

measuring a distance of the detected object from the sensing apparatus using the ultrasonic sensor data;

determining whether the measured distance falls within the first detection range;

guiding the process robot as a function of the ultrasonic sensor data when the measured distance exceeds the first detection range;

triggering on the detection arrangement formed of the laser light generator and the two optical sensors and generating laser range imaging data through the detection arrangement when the measured distance falls within the first detection range; and

guiding the process robot as a function of the laser range imaging data when the measured distance is within the first detection range.

20. The two-stage process according to claim 19, further comprising the steps of speeding up the process robot towards the detected object when the measured distance exceeds the first detection range, and triggering the detection arrangement in operation when the measured distance falls within the first detection range.