Omron Corporation

Atsushi Taneno

Shiro Fujieda

Yasuyuki Ikeda

Hiroshi Yano

Hajime Takegawa

Kenichi Ukai

Masanao Yoshino

Reiji Takahashi

One of stereo cameras is set such that a front view of a support surface of a workpiece is imaged, an image produced by the camera is displayed, and a range of an area where measurement processing is enabled is assigned by a rectangular frame. A manipulation assigning an upper limit and a lower limit of a height measurement range is accepted. When each assignment is fixed, zero is set as a z-coordinate to each constituent pixel of an image to which the rectangular frame is set, and a z-coordinate based on the upper limit of the height measurement range and a z-coordinate based on the lower limit are set to coordinates corresponding to the rectangular frame. Perspective transformation of three-dimensional information produced by the setting is performed from a direction of a line of sight set by a user, a produced projection image is displayed on a monitor.

Method for displaying measurement effective area in three-dimensional visual sensor and three-dimensional visual sensor

To easily generate model data having high recognition accuracy and being consistent with measurement conditions and installation environment of each of optical sensors. Basic model representing a range in which a workpiece can be optically recognized is inputted, and pieces of processing of imaging and measuring the workpiece under the same condition as that in an actual measurement and matching feature data of the workpiece obtained from this measurement with the basic model are executed for a plurality of number of cycles. Then, in the basic model, information is set as unnecessary information where the information cannot be associated with the feature data of the workpiece in all of the pieces of matching processing, or where the number of times or ratio the information cannot be associated is more than a predetermined reference value, or where the information cannot be associated with the feature data in any one of the pieces of executed matching processing. Then, the unnecessary information is deleted from the basic model, and information after each deletion is identified as model data to be registered and is registered to the memory.

Method for registering model data for optical recognition processing and optical sensor

In the present invention, whether three-dimensional measurement or checking processing with a model is properly performed by setting information and recognition processing result can easily be confirmed. After setting processing is performed to a three-dimensional visual sensor including a stereo camera, a real workpiece is imaged, the three-dimensional measurement is performed to an edge included in a produced stereo image, and restored three-dimensional information is checked with a three-dimensional model to compute a position of the workpiece and a rotation angle for an attitude indicated by the three-dimensional model. Thereafter, perspective transformation of the three-dimensional information on the edge obtained through measurement processing and the three-dimensional model to which coordinate transformation is already performed based on recognition result is performed into a coordinate system of a camera that performs the imaging, and projection images are displayed while being able to be checked with each other.

Three-dimensional recognition result displaying method and three-dimensional visual sensor

Enabling height recognition processing by setting a height of an arbitrary plane to zero for convenience of the recognition processing. A parameter for three-dimensional measurement is calculated and registered through calibration and, thereafter, an image pickup with a stereo camera is performed on a plane desired to be recognized as having a height of zero in actual recognition processing. Three-dimensional measurement using the registered parameter is performed on characteristic patterns (marks m, mand m) included in this plane. Based on a positional relationship between a plane defined as having a height of zero through the calibration and the plane expressed by the calculation equation, a transformation parameter (a homogeneous transformation matrix) for displacing points in the former plane into the latter plane is determined, and the registered parameter is changed using the transformation parameter.

Three-dimensional vision sensor

When computation of a three-dimensional measurement processing parameter is completed, accuracy of a computed parameter can easily be confirmed. After a parameter for three-dimensional measurement is computed through calibration processing using a calibration workpiece in which plural feature points whose positional relationship is well known can be extracted from an image produced by imaging, three-dimensional coordinate computing processing is performed using the computed parameter for the plural feature points included in the stereo image used to compute the parameter. Perspective transformation of each computed three-dimensional coordinate is performed to produce a projection image in which each post-perspective-transformation three-dimensional coordinate is expressed by a predetermined pattern, and the projection image is displayed on a monitor device.

Calibration apparatus and method for assisting accuracy confirmation of parameter for three-dimensional measurement

An object of the present invention is to enable performing height recognition processing by setting a height of an arbitrary plane to zero for convenience of the recognition processing. A parameter for three-dimensional measurement is calculated and registered through calibration and, thereafter, an image pickup with a stereo camera is performed on a plane desired to be recognized as having a height of zero in actual recognition processing. Further, three-dimensional measurement using the registered parameter is performed on characteristic patterns (marks m, mand m) included in this plane. Three or more three-dimensional coordinates are obtained through this measurement and, then, a calculation equation expressing a plane including these coordinates is derived. Further, based on a positional relationship between a plane defined as having a height of zero through the calibration and the plane expressed by the calculation equation, a transformation parameter (a homogeneous transformation matrix) for displacing points in the former plane into the latter plane is determined, and the registered parameter is changed using the transformation parameter.

Display suitable to an actual three-dimensional model or a recognition-target object is performed when stereoscopic display of a three-dimensional model is performed while correlated to an image used in three-dimensional recognition processing. After a position and a rotation angle of a workpiece are recognized through recognition processing using the three-dimensional model, coordinate transformation of the three-dimensional model is performed based on the recognition result, and a post-coordinate-transformation Z-coordinate is corrected according to an angle (elevation angle f) formed between a direction of a line of sight and an imaging surface. Then perspective transformation of the post-correction three-dimensional model into a coordinate system of a camera of a processing object is performed, and a height according to a pre-correction Z-coordinate at a corresponding point of the pre-coordinate-transformation three-dimensional model is set to each point of a produced projection image. Projection processing is performed from a specified direction of a line of sight to a point group that is three-dimensionally distributed by the processing, thereby producing a stereoscopic image of the three-dimensional model.

Method for displaying recognition result obtained by three-dimensional visual sensor and three-dimensional visual sensor

In the present invention, processing for setting a parameter expressing a measurement condition of three-dimensional measurement to a value necessary to output a proper recognition result is easily performed. The three-dimensional measurement is performed to stereo images of real models WMand WMof a workpiece using a measurement parameter set by a user, and positions and attitudes of the workpiece models WMand WMare recognized based on the measurement result. An image expressing the recognition result is displayed, and numerical data indicating the selected recognition result is set to sample data in response to a user manipulation for selecting the recognition result. A setting value of the measurement parameter is changed every time in a predetermined numerical range, the three-dimensional measurement and recognition processing are performed using the setting measurement parameter, and a numerical range of the setting parameter is set to an acceptable range when the recognition result in which an amount of difference with sample data falls within a predetermined value is obtained. An intermediate value of the acceptable range is fixed and registered as an optimum value of the parameter.

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Kyoto, Japan

Atsushi Taneno