TECHNICAL FIELD

A method, system and computer program product are provided in accordance with an example embodiment in order to align wire contacts with insertion holes of a connector, and more particularly, to using a machine-vision system to automatically align wire contacts with wire contact insertion holes of a connector and to insert the wire contacts into respective holes of the connector.

BACKGROUND

Wire bundles consisting of a plurality of wires are utilized in a variety of industries to carry a myriad of different types of signals. The wire of a wire bundle assembly must frequently be terminated with a wire contact and the resulting wire end is inserted into a wire contact insertion hole of a connector, such as in a rubber grommet of a connector. As each wire of a wire bundle is unique and may carry a different type of signal, the wire ends of a wire bundle assembly must be inserted into specific wire contact insertion holes of a connector in order to make the proper connections.

The wire ends of a wire bundle assembly may be manually inserted into the respective wire contact insertion holes defined by a connector. As wire bundle assemblies commonly include hundreds of wires, this manual connection process may be relatively time consuming and error prone and, as a result, may increase the cost of the overall assembly including the wire bundle assembly. As such, automated techniques to insert the wire ends of a wire bundle assembly into the wire contact insertion holes of a connector have been developed in an effort to reduce the time expended to make the connections and to correspondingly reduce the cost of the resulting assembly. However, wire bundle assembly machines generally require the connectors to be in a very restricted and controlled set of locations in order to increase the likelihood that the wire ends of the wire bundle assembly may be properly inserted into the wire contact insertion holes of the connector. As such, wire bundle assembly machines limit the flexibility with which connectors may be presented and, as such, are not suitable for all scenarios.

BRIEF SUMMARY

A method, system and computer program product are provided for aligning wire contacts with insertion holes defined by a connector so as to facilitate the automated insertion of the wire ends of a wire bundle assembly into the wire contact insertion holes of a connector. By facilitating the automated insertion of the wire ends of a wire bundle assembly into the wire contact insertion holes of a connector, the time required to establish such connections and correspondingly the cost associated with the resulting assembly may be reduced while reducing the error rate associated with the connections. The method, system and computer program product of an example embodiment provide substantial flexibility in relation to the manner in which the connector may be located, while still permitting the wire ends of a wire bundle assembly to be securely inserted into and electrically connected to the appropriate wire contact insertion holes of the connector.

In an example embodiment, a system is provided to align wire contacts with insertion holes of a connector and to insert the wire connectors into respective holes of the connector. The system may include a robot having an end-effector, where the end-effector includes a wire gripper and at least two image capture devices secured to the end-effector; and a computing device. The computing device may be configured to: process images captured by the image capture devices to establish a corrective transformation to align the wire contact with the target hole of the connector in a connector surface; cause the robot to translate the end-effector to move the wire gripper along the corrective transformation; cause the robot to advance the end-effector until contact is made with the connector surface; identify, based on force measurements, if the wire contact is inside the target hole of the connector; cause the robot to advance the end-effector to move the wire contact toward the connector a predetermined additional amount more; and identify, based on movement of the wire contact the predetermined additional amount more, if alignment is correct from force feedback at the wire gripper.

According to some embodiments, the computing device configured to identify, based on force measurements, if the wire contact is inside the target hole of the connector, is configured to: identify that the wire contact is not aligned with the target hole of the connector in response to a force observed at the wire gripper above a predefined value; and identify that the wire contact is aligned with the target hole of the connector in response to the force observed at the wire gripper being below the predefined value. The computing device configured to process images captured by the image capture devices to establish corrective transformation to align the wire contact with the target hole of the connector may be configured to: identify, within the processed images, a tip of the wire contact and a direction along which the wire contact extends; and establish a corrective transformation to align the tip of the wire contact and the direction along which the wire contact extends with the target hole in an axis of a three-dimensional coordinate system of the robot end-effector from the processed images.

The computing device of some embodiments may be configured to: determine a maximum distance the wire gripper can advance toward the connector; cause the robot to advance the end-effector to move the wire gripper toward the connector; as the robot is caused to advance the end-effector to move the wire gripper toward the connector, in response to force feedback on the wire gripper satisfying an insertion force value, determine that the wire contact is fully inserted into the connector; and as the robot is caused to advance the end-effector to move the wire gripper toward the connector, in response to force feedback on the wire gripper failing to satisfy the insertion force value before reaching the maximum distance the wire gripper can advance toward the connector, determine that the wire contact is not fully inserted into the connector. In response to the computing device determining that the wire contact is fully inserted into the connector, the computing device is further configured to: cause the robot to retract the end-effector to move the wire gripper away from the connector; and in response to the wire gripper moving a pull distance without force feedback on the wire gripper exceeding a pull test value, identify the wire contact as improperly inserted; in response to force feedback on the wire gripper exceeding a pull test value without the wire gripper having moved a pull distance, identify the wire contact as properly inserted.

According to some embodiments, in response to the computing device determining that the contact is not fully inserted into the connector, the computing device may further be configured to: cause the wire gripper to release a grip on the wire contact; cause the robot to retract the end-effector to move the wire gripper away from the connector; cause the wire gripper to re-grip the wire contact; and cause the robot to advance the end-effector to move the wire gripper and the wire contact toward the connector. According to some example embodiments, force feedback may be established based on a force sensor disposed between the robot and the wire gripper. A tool interfaces with force torque sensor may be employed between the robot and the end effector in such a way that the force torque sensor may be able to accurately detect forces in three orthogonal axes and torques about each of those three axes. Another example embodiment which may be used instead of or in combination with a force torque sensor arrangement is a strain gauge in the gripper, or a strain gauge array. A single strain gauge may not be able to establish the axis along which a force is received but may be used in an example embodiment to detect the force feedback of a wire contact inserted or pulled from a connector. A strain gauge array may be used to identify the axes along which forces are received if desired. The computing device of some embodiments may be configured to: identify, in images captured by the image capture devices, the orientation of a visible portion of the wire contact; and compute a corrective movement in a coordinate frame of the robot end effector using the orientation of the wire contact.

Embodiments provided herein may include a method to align and insert a wire contact into a target hole of a connector. Methods may include: obtaining captured images, from at least two image capture devices attached to an end-effector of a robot, of a wire gripper of the end-effector; processing images captured by the image capture devices to establish a corrective transformation to align the wire contact with the target hole of the connector in a connector surface; causing the robot to translate the end-effector to move the wire gripper along the corrective transformation; causing the robot to advance the end-effector until contact is made with the connector surface; identify, based on force measurements, if the wire contact is inside the target hole of the connector; causing the robot to advance the end-effector to move the wire contact toward the connector a predetermined additional amount more; and identifying, based on movement of the wire contact the predetermined additional amount more, if alignment is correct from force feedback at the wire gripper.

According to some embodiments, identifying, based on force measurements, if the wire contact is inside the target hole of the connector may include: identifying that the wire contact is not aligned with the target hole of the connector in response to a force observed at the wire gripper above a predefined value; and identifying that the wire contact is aligned with the target hole of the connector in response to the force observed at the wire gripper being below the predefined value. Processing images captured by the image capture devices to establish corrective transformation to align the wire contact with the target hole of the connector may include: identifying, within the processed images, a tip of the wire contact and a direction along which the wire contact extends; and establishing a corrective transformation to align the tip of the wire contact and the direction along which the wire contact extends with the target hole in an axis of a three-dimensional coordinate system of the robot end-effector from the processed images.

Methods may include: determining a maximum distance the wire gripper can advance toward the connector; causing the robot to advance the end-effector to move the wire gripper toward the connector; as the robot is caused to advance the end-effector to move the wire gripper toward the connector, in response to force feedback on the wire gripper satisfying an insertion force value, determining that the wire contact is fully inserted into the connector; and as the robot is caused to advance the end-effector to move the wire gripper toward the connector, in response to force feedback on the wire gripper failing to satisfy the insertion force value before reaching the maximum distance the wire gripper can advance toward the connector, determining that the wire contact is not fully inserted into the connector.

According to some embodiments, in response to determining that the wire contact is fully inserted into the connector, methods may include: causing the robot to retract the end-effector to move the wire gripper away from the connector; and in response to the wire gripper moving a pull distance without force feedback on the wire gripper exceeding a pull test value, identifying the wire contact as improperly inserted; in response to force feedback on the wire gripper exceeding a pull test value without the wire gripper having moved a pull distance, identifying the wire contact as properly inserted. In response to determining that the wire contact is not fully inserted into the connector, methods may include: causing the wire gripper to release a grip on the wire contact; causing the robot to retract the end-effector to move the wire gripper away from the connector; causing the wire gripper to re-grip the wire contact; and causing the robot to advance the end-effector to move the wire gripper and the wire contact toward the connector. Force feedback at the wire gripper may be established based on a force sensor between the robot and the wire gripper. Methods may optionally include: identifying, in images captured by the image capture devices, the orientation of a visible portion of the wire contact; and computing a corrective movement in a coordinate frame of the robot end effector using the orientation of the wire contact.

Embodiments provided herein may include a computer program product for aligning and inserting a wire contact into a target hole defined by a connector. The computer program product may include at least one non-transitory computer-readable storage medium having computer-executable program code instructions stored therein. The computer-executable program code instructions including program code instructions to: obtain captured images from at least two image capture devices attached to an end-effector of a robot, of a wire gripper of the end-effector; process images captured by the image capture devices to establish a corrective transformation to align the wire contact with the target hole of the connector in a connector surface; cause the robot to translate the end-effector to move the wire gripper along the corrective transformation; cause the robot to advance the end-effector until contact is made with the connector surface; identify, based on force measurements, if the wire contact is inside the target hole of the connector; cause the robot to advance the end-effector to move the wire contact toward the connector a predetermined additional amount more; and identify, based on movement of the wire contact the predetermined additional amount, if alignment is correct from the force feedback at the wire gripper.

The program code instructions to identify, based on force measurements, if the wire contact is inside the target hole of the connector, may include program code instructions to: identify that the wire contact is not aligned with the target hole of the connector in response to a force observed at the wire gripper above a predefined value; and identify that the wire contact is aligned with the target hole of the connector in response to the force observed at the wire gripper below the predefined value. The program code instructions to process images captured by the image capture devices to establish corrective transformation to align the wire contact with the target hole of the connector may include program code instructions to: identify, within the processed images, a tip of the wire contact and a direction along which the wire contact extends; and establish a corrective transformation to align the tip of the wire contact and the direction along which the wire contact extends with the target hole in an axis of a three-dimensional coordinate system of the robot end-effector from the processed images.

According to some embodiments, the computer program product may include program code instructions to: determine a maximum distance the wire gripper can advance toward the connector; cause the robot to advance the end-effector to move the wire gripper toward the connector; as the robot is caused to advance the end-effector to move the wire gripper toward the connector, in response to force feedback on the wire gripper satisfying an insertion force value, determine that the wire contact is fully inserted into the connector; and as the robot is caused to advance the end-effector to move the wire gripper toward the connector, in response to force feedback on the wire gripper failing to satisfy the insertion force value before reaching the maximum distance the wire gripper can advance toward the connector, determine that the wire contact is not fully inserted into the connector.

In response to determining that the wire contact is fully inserted into the connector, according to some embodiments, the computer program product may include program code instructions to: cause the robot to retract the end-effector to move the wire gripper away from the connector; and in response to the wire gripper moving a pull distance without force feedback on the wire gripper exceeding a pull test value, identify the wire contact as properly inserted; in response to force feedback on the wire gripper exceeding a pull test value without the wire gripper having moved a pull distance, identify the wire contact as properly inserted. In response to determining that the wire contact is not fully inserted into the connector, the computer program product may include program code instructions to: cause the wire gripper to release a grip on the wire contact; cause the robot to retract the end-effector to move the wire gripper away from the connector; cause the wire gripper to re-grip the wire contact; and cause the robot to advance the end-effector to move the wire gripper and the wire contact toward the connector.

Embodiments provided herein may include an apparatus to align and insert a wire contact into a target hole of a connector. An example apparatus may include: means for obtaining captured images, from at least two image capture devices attached to an end-effector of a robot, of a wire gripper of the end-effector; means for processing images captured by the image capture devices to establish a corrective transformation to align the wire contact with the target hole of the connector in a connector surface; means for causing the robot to translate the end-effector to move the wire gripper along the corrective transformation; means for causing the robot to advance the end-effector until contact is made with the connector surface; identify, based on force measurements, if the wire contact is inside the target hole of the connector; means for causing the robot to advance the end-effector to move the wire contact toward the connector a predetermined additional amount more; and means for identifying, based on movement of the wire contact the predetermined additional amount more, if alignment is correct from force feedback at the wire gripper.

According to some embodiments, the means for identifying, based on force measurements, if the wire contact is inside the target hole of the connector, may include: means for identifying that the wire contact is not aligned with the target hole of the connector in response to a force observed at the wire gripper above a predefined value; and means for identifying that the wire contact is aligned with the target hole of the connector in response to the force observed at the wire gripper being below the predefined value. The means for processing images captured by the image capture devices to establish corrective transformation to align the wire contact with the target hole of the connector may include: means for identifying, within the processed images, a tip of the wire contact and a direction along which the wire contact extends; and means for establishing a corrective transformation to align the tip of the wire contact and the direction along which the wire contact extends with the target hole in an axis of a three-dimensional coordinate system of the robot end-effector from the processed images.

Embodiments of an apparatus may include: means for determining a maximum distance the wire gripper can advance toward the connector; means for causing the robot to advance the end-effector to move the wire gripper toward the connector; as the robot is caused to advance the end-effector to move the wire gripper toward the connector, in response to force feedback on the wire gripper satisfying an insertion force value, means for determining that the wire contact is fully inserted into the connector; and as the robot is caused to advance the end-effector to move the wire gripper toward the connector, in response to force feedback on the wire gripper failing to satisfy the insertion force value before reaching the maximum distance the wire gripper can advance toward the connector, means for determining that the wire contact is not fully inserted into the connector.

According to some embodiments, in response to determining that the wire contact is fully inserted into the connector, an apparatus may include: means for causing the robot to retract the end-effector to move the wire gripper away from the connector; and in response to the wire gripper moving a pull distance without force feedback on the wire gripper exceeding a pull test value, means for identifying the wire contact as improperly inserted; in response to force feedback on the wire gripper exceeding a pull test value without the wire gripper having moved a pull distance, means for identifying the wire contact as properly inserted. In response to determining that the wire contact is not fully inserted into the connector, an apparatus may include: means for causing the wire gripper to release a grip on the wire contact; means for causing the robot to retract the end-effector to move the wire gripper away from the connector; means for causing the wire gripper to re-grip the wire contact; and means for causing the robot to advance the end-effector to move the wire gripper and the wire contact toward the connector. Force feedback at the wire gripper may be established based on a force sensor between the robot and the wire gripper. An example apparatus may further include: means for identifying, in images captured by the image capture devices, the orientation of a visible portion of the wire contact; and computing a corrective movement in a coordinate frame of the robot end effector using the orientation of the wire contact.

