Robotic drill system and method of drilling using robotic drill system

Abstract

To provide a robotic drill system and a method of drilling using the robotic drill system.SOLUTION: The method includes inserting a tool head of a robotic drill into a hole of a drill template along an initial insertion trajectory using a robotic manipulator arm that is moved by at least one robotic actuator for causing robotic insertion of the tool head. The method includes, in response to binding of the tool head to a wall of the hole while inserting the tool head along the initial insertion trajectory, stopping robotic insertion of the tool head and activating a self-centering device of the tool head to reorient the tool head to a corrected alignment of a tool head axis relative to the hole. The self-centering device may include an expandable collet.SELECTED DRAWING: Figure 1

Description

Technical Field

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[0003]

[0001] The present disclosure broadly relates to robotic drilling. In particular, embodiments of the present disclosure relate to robotic drill systems, robotic drill methods, and computer-implemented methods of robotic drilling that use drill templates.

Background Art

[0002] When performing a robotic peg-in-hole process such as robotic drilling using holes in a drill template, the robot must first detect the hole. One approach is to use a laser scanner to precisely locate surface features, which is highly accurate but can be time-consuming. Another approach is to use a calibrated vision system, which is faster but may be less accurate. [[ID=​​​​​Throughout this specification, the word “comprise,” or variations such as “comprising,” are understood to mean that they include the elements, integers, or steps, or groups of elements, integers, or steps, but do not exclude any other elements, integers, or steps, or groups of elements, integers, or steps.

[0005] No discussion relating to any documents, acts, materials, apparatus, articles, etc. contained herein shall be construed as relating to any part or all of such matters to any prior art or general knowledge in the art relating to this disclosure that existed prior to the priority date of any of the attached claims. [Overview of the project]

[0006] This disclosure provides a robotic drill system comprising a tool head, a robotic manipulator for supporting the tool head, at least one robotic actuator, and at least one sensor. The tool head includes an expandable collet and an end effector. In this case, the expandable collet is configured to expand between a retracted configuration and an expanded configuration for insertion into a hole in a drill template. At least one robotic actuator is configured to move a robotic manipulator arm to bring about robotic insertion of the tool head directed into the hole in the drill template. At least one sensor is configured to detect constraint of the expandable collet in the hole in the drill template. In response to the detection of constraint of the expandable collet in the hole, robotic insertion of the tool head is stopped, and the expandable collet is configured to expand into an expanded configuration to center the end effector in the hole. The retracted diameter of the expandable collet in the retracted configuration is at least 95% but less than 100% of the diameter of the hole in the template hole.

[0007] This disclosure also provides a method for drilling using a robotic drill system. The method includes inserting the tool head of a robotic drill into a hole in a drill template along an initial insertion trajectory using a robotic manipulator arm moved by at least one robotic actuator to bring about robotic insertion of the tool head. The method also includes detecting constraints on the tool head to the walls of the hole. While inserting the tool head along the initial insertion trajectory, in response to constraints on the tool head to the walls of the hole, the method includes stopping the robotic insertion of the tool head and activating a self-centering device for the tool head to reorient the tool head to a corrected alignment of the tool head axis with respect to the hole. The method also includes inserting the tool head into the hole along the updated insertion trajectory, in which case the updated insertion trajectory is based on the corrected alignment. The method also includes activating the end effector of the tool head.

[0008] This disclosure provides a non-transient computer-readable storage medium having computer-readable program code internally. When executed by a processor, the program code causes a computer system to perform at least the following: calculate an initial control signal for a robot actuator to insert the tool head of a robot drill toward a hole in a drill template along an initial insertion trajectory; transmit a control signal to the robot actuator to insert the tool head toward the hole along the initial insertion trajectory; and receive sensor signals representing the constraint of the tool head toward the hole wall. The computer-readable program causes the computer system to determine the constraint of the tool head toward the hole wall based on the sensor signals; transmit an activation control signal to activate the self-centering device of the tool head in order to reposition the tool head toward a corrected alignment toward the hole; calculate an updated insertion trajectory based on the corrected alignment of the tool head toward the hole; transmit an updated control signal to the robot actuator to insert the tool head toward the hole along the updated insertion trajectory; and transmit an end-effector control signal to activate the end-effector of the tool head. [Brief explanation of the drawing]

[0009] [Figure 1] A schematic diagram of an exemplary embodiment of a robotic drilling system is shown. [Figure 2]Figures 2(a) to 2(f) show the sequence of the toolhead of the robotic drill system being inserted into the hole in the drill template. Figure 2(a) shows the constraint of the toolhead during insertion in the initial insertion trajectory. Figure 2(b) shows the activation of the toolhead's self-centering device, such as expanding the expandable collet 7. Figure 2(c) shows the toolhead reoriented to the corrected alignment due to the activation of the self-centering device. Figure 2(d) shows the toolhead in the corrected alignment with the self-centering device deactivated. Figure 2(e) shows the toolhead being inserted along the updated insertion trajectory. Figure 2(f) shows the activation of the self-centering device to fix the toolhead in the hole and the activation of the end effector 9. [Figure 3] This is a flowchart illustrating one exemplary embodiment of a drilling method using a robotic drilling system. [Figure 4] This is a flowchart of further steps in the drilling method, including calculating updated control signals to insert the tool head along the updated insertion trajectory. [Figure 5] This is a flowchart of further steps in the drilling method, including securing the tool head to the hole in the drill template. [Figure 6] This is a flowchart illustrating one exemplary embodiment of a method implemented in a computer that controls a robotic drilling system. [Figure 7] Figure 7(a) shows an end view of the tool head in a retracted configuration. Figure 7(b) shows an end view of the tool head in an extended configuration. [Modes for carrying out the invention]

[0010] overview Figure 1 shows an embodiment of the robotic drilling system 1 for activating the end effector 9 in a workpiece 8. Figure 3 shows a drilling method 100 using the robotic drilling system 1, which is illustrated by the sequence shown in Figures 2(a) to 2(f).

[0011] The robotic drilling system 1 is used with a drill template 23 having one or more holes 21 corresponding to one or more positions for the end effector 9 of the tool head 5 in order to perform a process on the workpiece 8. The drill template 23 is used as a jig to guide the tool head 5 onto the workpiece.

[0012] The robotic drill system 1 includes a manipulator arm 15 for supporting a tool head 5. One or more robotic actuators 17 are provided to move the robotic manipulator arm to bring about robotic insertion 110 of the tool head 5 directed into a hole 21 in a drill template 23.

[0013] The tool head 5 includes a selectively activated self-centering device 41 and an end effector 9. In some specific embodiments, the self-centering device 41 is an expandable collet 7. It is configured to expand between a retracted configuration 11 and an expanded configuration 13 for insertion into a hole 21. The end effector 9 performs a process on the workpiece 8 and may include, for example, a drill bit, a cutting tool, or other tool head.

[0014] The robotic drilling system 1 also includes at least one sensor 19 for detecting constraints on the tool head 5 within the hole 21 of the drill template 23. This may include detecting constraints on at least a portion of the self-centering device 41 or the expandable collet 7 relative to the hole 21 (120).

[0015] If a constraint is detected during robotic insertion of the tool head 5 directed into the hole 5, the robotic drill system 1 stops the robotic insertion accordingly. A self-centering device is activated to correct the alignment of the tool head 5 (130). In a specific embodiment of the expandable collet 7, this includes expanding the diameter of the expandable collet 7 toward the wall 22 of the hole 21. In this expanded configuration 13, the expandable collet 7 centers the tool head 5 and the end effector 9 in the hole 21.

[0016] Following the correction of the alignment of the tool head 5, the robotic manipulator arm can insert the tool head 5 into the hole 21 along an updated trajectory based on the corrected alignment 43 (140). This allows the tool head 5 to be inserted into the desired designated position 47. The end effector 9 can then be activated to perform the process on the workpiece 8 (150).

[0017] The robotic drilling system 1 and method 100 enable precise positioning of the end effector 9 within the drill template 23. In particular, the alignment of the tool head 5 is corrected using a self-centering device 41 such as an expandable collet 7. This may be advantageous for systems using less precise sensors and components, where precisely positioning the tool head 5 is difficult and results in undesirable consequences of the tool head 5 being constrained to the template 23.

[0018] Next, a detailed embodiment of the components of the robot drill system 1 will be described.

[0019] Toolhead 5 Referring to Figures 1, 7(a), and 7(b), the tool head 5 includes an end effector 9 for performing a process on the workpiece 8, and a self-centering device 41 for correcting the alignment of the end effector 9.

[0020] The tool head 5 may include other components such as a sensor 19 for detecting constraints, a collet sensor 53 for detecting forces in the self-centering device 41, and an actuator for driving the end effector 9.

[0021] End Effector 9 The end effector 9 performs operations on the workpiece 8. This may include a removal process (also known as a subtractive manufacturing process). In one embodiment, the end effector 9 includes a drill having a drill bit. The end effector may include, or be associated with, a rotary actuator such as a motor for selectively rotating the drill bit to drill into the workpiece 8.

[0022] In some embodiments, at least a portion of the end effector 9 is linearly extendable relative to other portions of the tool head 5 (such as the expandable collet 7) along the tool head axis 49. This can assist in drilling while the remaining portion of the tool head 5 is maintained in a stationary state.

[0023] Self-centered device 41 The self-centering device 41 is configured to place the end effector 9 at the center of the hole 21 (including aligning the end effector 9 with the hole 21). This can be achieved using the self-centering device 41 of the tool head 5 that applies a force to the wall 22 of the hole 21. Thereby, the relative position of the end effector 9 is placed at the center of the hole 21.

[0024] In some embodiments, the self-centering device 41 includes an expandable collet 7. In this case, the outer diameter of the expandable collet 7 is selectively adjustable (which will be described in more detail below). In other embodiments, the self-centering device 41 includes a plurality of radially expandable arms, thereby synchronizing the selective distance of the distal end of each expandable arm to the center. It will be understood that other centering devices may be employed to center the end effector 9.

[0025] Expandable Colette 7 In an exemplary embodiment shown in Figures 1, 2, 7(a), and 7(b), the self-centering device 41 may take the form of an expandable collet 7. It is configured to expand between a retracted configuration 11 for insertion into a hole and an expanded configuration 13 for centering the end effector 9 within the hole 21.

[0026] The expandable collet may have a substantially cylindrical outer surface. This ensures that when in the expanded configuration 13 (which may be close to or the same as the diameter of the template hole), the outer surface makes substantially uniform contact with the corresponding cylindrical wall 22 of the hole 21. The outer surface may have several slots to facilitate the expansion and retraction of the collet 7.

[0027] In some embodiments, the retracted diameter 27 of the expandable collet 7 is at least 95% but less than 100% of the diameter of the template hole 21. In some embodiments, the retracted diameter 27 of the expandable collet 7 is in the range of 95% to 97% of the diameter of the template hole. In some embodiments, the retracted diameter 27 of the expandable collet 7 is in the range of 97% to 99% of the diameter of the template hole. In some further embodiments, the retracted diameter 27 of the expandable collet is in the range of at least 99% but less than 100% of the diameter of the template hole.

[0028] The expanded configuration 13 of the expandable collet 7 may include an expanded diameter 28 of 100% or approximately 100% of the expected diameter of the template hole. This can provide a tight and precise fit, thereby ensuring that the end effector 9 is centered on the hole 21 and precisely aligned with the hole 21.

[0029] In some further embodiments, the expandable collet 7 is configured to allow the expandable collet to have an unconstrained expanded diameter 28 that is larger than the expected diameter of the template hole. This allows the expandable collet 7 to expand toward a larger diameter 28 in order to tightly fit the expandable collet 7 and the corresponding tool head 5 into the hole 21 of the drill template 23. This may be useful for one further function, which is to secure the tool head 5 in the hole 21 during the activation of the end effector 9.

[0030] In some embodiments, the collet sensor 53 is configured to output a collet sensor output representing the force between the expandable collet 7 and the wall of the hole 21. When expanding toward the expanded configuration, the diameter of the expandable collet 7 expands until the collet sensor output reaches or exceeds a threshold. This may be useful to limit the amount of expansion of the expandable collet 7 to prevent damage to the drill template 23. The collet sensor output may also be used as an indicator that the expandable collet is tightly fitted and secured in the hole 21.

[0031] In some embodiments, the expandable collet 7 is configured to expand and retract using a gas-pressure system. This may also include using a gas-pressure actuator to expand the expandable collet 7. In some embodiments, the force exerted by the expandable collet 7 on the wall of the hole 21 in the drill template 23 is controlled by specifying or otherwise controlling the pressure in the gas-pressure cylinder of the gas-pressure system.

[0032] Lead-in chamfer 29 The robotic manipulator arm 15 is configured to insert at least a portion of the tool head 5 into the hole 21 of the drill template 23. This can be thought of as a peg-in-hole operation. To assist in the insertion of the tool head 5, the tool head 5 may include an introduction groove 29. The introduction groove 29 includes an introduction edge 31. In this case, the introduction edge 31 has an introduction diameter 34 less than the retracted diameter 27 of the expandable collet 7. In some embodiments, the introduction diameter is at least 75% of the diameter of the hole 21 of the template hole. In other embodiments, the introduction diameter is at least 80% of the diameter of the template hole. In yet another embodiment, the introduction diameter is at least 90% of the diameter of the template hole. In yet another embodiment, the introduction diameter is at least 95% of the diameter of the template hole.

[0033] In some embodiments, the introduction diameter includes a frustoconical portion.

[0034] Robot manipulator arm 15 and robot actuator 17 The robot manipulator arm 15 can be articulated with multiple degrees of freedom. In some embodiments, this may include a robot manipulator arm 15 that can translate the tool head 5 along the x, y, and z axes. The robot manipulator arm 15 may also rotate the tool head 5 around the corresponding x, y, and z axes.

[0035] The robot manipulator arm 15 is moved by one or more robot actuators 17. The robot actuators 17 may include linear or rotary motors, gas-pressure actuators, hydraulic actuators, or a combination thereof.

[0036] The robot manipulator arm 15 may be configured in either a driven mode or a free-drive mode in cooperation with the sensor and controller 30. In driven mode, the controller 30 receives an instruction command to move the manipulator arm to bring about the insertion of the tool head, and accordingly transmits a control signal to selectively activate one or more of the robot actuators 17 to affect the insertion operation. Driven mode may also be used for other desired movements of the robot manipulator arm of the tool head 5, such as retracting the tool head 5 from the hole 21 or moving the tool head 5 towards another hole in the drill template 23.

[0037] The robot manipulator arm 15 may also be configured in a compliant free-drive mode (also known as "zero-gravity" mode). In compliant free-drive mode, the robot manipulator arm 15 is configured to be freely repositionable to facilitate the movement of the tool head. The robot manipulator arm 15 moves (including translation and rotation) based on external forces applied to the robot manipulator arm 15 or the tool head 5. This may include sensors within the robot manipulator arm detecting external forces on components of the robot manipulator arm 15 and acting on robot actuators 17 in accordance with the force and / or movement.

[0038] The obedient free-drive mode allows the tool head 5 and end effector 9 to move to the corrected alignment 43 of the tool head axis 49 relative to the hole 21 by the force generated when the self-centering device 41 is activated.

[0039] Sensor 19 The robotic drill system 1 includes one or more sensors 19, 19', 19'' for detecting the constraint of the expandable collet 7 on the hole 21. In some embodiments, sensor 19 may be similar to or the same as a collet sensor 53 that detects a force directed on the expandable collet 7.

[0040] In other embodiments, sensors 19, 19', and 19'' may indirectly detect the constraint of the tool head 5 on the wall of the hole. For example, they may measure forces or metrics on other parts of the robotic manipulator arm 15 associated with the robotic actuator 17.

[0041] In some embodiments, the sensor 19 may include sensors for detecting changes in current, voltage, and / or heat in at least one robot actuator 17. This can be used to estimate the resistance to movement in the toolhead 5, which represents a constraint.

[0042] In some embodiments, the sensor 19 includes a force sensor for detecting at least one force in the tool head 5, the expandable collet 7, the robot actuator 17, the robot manipulator arm 15, or the drill template 23. In some embodiments, the force sensor may be a magnitude-based sensor for detecting force. In some embodiments, this may be based on a less expensive sensor that detects force in any direction (as opposed to a more expensive sensor that detects (one or more) forces in the direction of a particular component).

[0043] In some embodiments, the sensor 19 may include an accelerometer for detecting changes in the acceleration of the collet 7 or the tool head 5.

[0044] In some embodiments, the sensor detects electrical conductivity or a change in capacitance between the collet 7 or tool head 5 and the drill template 23.

[0045] In some embodiments, the tool head 5 is provided with a tool head sensor for detecting when the tool head 5 is inserted into a specified position (such as the correct depth of the tool head 5 in the hole 21 of the drill template 23). This may include an induction sensor for detecting the presence of ferrous metal. In some embodiments, the drill template 23 includes ferrous metal. Thereafter, the induction sensor provides an output based on the detection of the drill template 23's proximity to the ferrous metal. This may be used as part of an interlock system for the end effector 9. Thereafter, the end effector 9 can be activated selectively only if the induction sensor provides an output indicating that the tool head 5 is in the specified position. In some embodiments, the specified position may include a range of distances between the tool head sensor on the tool head and the drill template 23. In one embodiment, the range may include 1 to 2 mm between the tool head sensor and the drill template 23.

[0046] In other embodiments, the tool head may be equipped with an optical distance sensor to provide an output representing the relative distance between the tool head 5 and the drill template. This can be used to determine whether the tool head 5 has advanced to a specified depth in the hole 21 of the drill template 23.

[0047] The sensor 19 of the robotic drill system 1 may also include a position sensor for transmitting a position sensor signal representing the position and / or alignment of the tool head 5. This may include identifying the position and / or alignment of the tool head in a corrected alignment. In some embodiments, this may include a rotary encoder associated with the robotic manipulator arm 15, the robotic actuator 17, and the tool head 3. This information, which may include information on the relative position and / or alignment of the tool head 5 to the robotic drill system 1, may be used by the controller to calculate the updated insertion trajectory.

[0048] Sensor 33 with limited precision The robotic drilling system 1 may include a limited-precision sensor 33 for providing a limited-precision sensor feedback signal 35 to guide the insertion of the tool head 5, which is directed into the hole 21 along an initial insertion trajectory.

[0049] In some embodiments, the limited-precision sensor 33 is a camera. The limited-precision sensor feedback signal 35 may include an image (or video) of the tool head 5 (or other component of the robot manipulator arm 15) relative to the hole 21 in the drill template 23. This information may be used by the controller 30 to identify an initial insertion trajectory 37 that is fine enough to initially insert a portion of the tool head 5 into the hole 21. After the initial insertion, if the precision provided by the limited-precision sensor is insufficient for precise positioning of the tool head 5 into the hole 21, the above-described method using the self-centering device 41 is used to correct the alignment of the tool head 5.

[0050] In some embodiments, the limited-precision sensor 33 includes a depth camera having depth sensing capability. For example, a system having multiple cameras provides stereo depth data. In other embodiments, the limited-precision sensor 33 includes one or more encoded optical depth cameras that project a light pattern and capture the reflected light pattern to determine the depth.

[0051] The advantage of using a sensor 33 with limited precision, such as a video camera, is its low cost. The video camera is also suitable in that it can be configured to have a wide field of view to enable processing on larger drill templates 23 and workpieces 8. This also allows for a robotic drilling system 1 that is portable, easily set up, and easily initialized. This can be in contrast to systems that rely on expensive laser scanners, which require precise alignment and calibration of components.

[0052] Controller (30) The controller 30 may include one or more processors for executing computer-readable program code stored in a non-transient computer-readable storage medium. The controller may include a computer, a computer system, or a distributed computer system on a network. In other embodiments, the controller 30 may include a microprocessor that includes a reduced instruction set computer.

[0053] The controller 30 is configured to execute program instruction code to perform method 100 and control the robot drill system 1. This may include receiving sensor signals from sensors 19 and 53, and transmitting control signals to the robot actuator 17, the self-centering device 41, and the end effector 9. The controller 30 may also be used to calculate control signals and insertion trajectories for the robot drill system 1. In this embodiment, the execution of the program code causes a computer system to perform method 200 shown in Figure 6.

[0054] Drill template 23 and workpiece 8 The drill template 23 may be constructed from a stable, rigid material. This may include a material selected to have minimal thermal expansion or contraction within the operating temperature range in order to minimize variation in the position of the (one or more) holes 21. In some embodiments, the drill template 23 may be constructed from a metallic alloy. In some embodiments, the drill template 23 is constructed from an iron alloy or a semi-iron alloy (such as a semi-iron aluminum alloy).

[0055] Workpiece 8 may include various solid materials that require drilling. These may include composite materials (e.g., fiber-reinforced plastics), metal alloys, wood, and the like. In some embodiments, workpiece 8 may be a component of an aircraft.

[0056] During robotic drilling, the drill template 23 is positioned appropriately on the workpiece 8 in a consistent manner. This may include mounting the drill template 23 to the workpiece 8. In some embodiments, this may include fixing the drill template 23 to the workpiece 8 using a fixture, fastening the drill template 23 to the workpiece 8, or positioning the drill template 23 on the workpiece 8 by other means.

[0057] Robot drilling method 100 Next, a specific embodiment of the robotic drilling method 100 will be described with reference to Figures 3 to 6. This embodiment will be described with reference to the corresponding sequence shown in Figures 2(a) to 2(f).

[0058] The method includes the controller 30 calculating an initial control signal to the robot actuator 17 for inserting the tool head 5 into the hole 21 of the drill template 23 along an initial insertion trajectory 37 (210). This may include receiving a feedback signal 35 of the position and / or orientation of the tool head 5 relative to the hole 21 from a sensor with limited precision, and calculating the initial insertion trajectory 37 to position the tool head 5 in the hole 21.

[0059] Next, an initial control signal is sent to the robot actuator 17 (220). This allows the robot manipulator arm 15 to insert the tool head 5 into the hole 21 along the initial insertion trajectory 37 (110). When inserting the tool head 5, the expandable collet 7 is typically in a retracted configuration 11.

[0060] When the tool head 5 is inserted along the initial insertion trajectory 37, there may be slight errors that result in imprecise alignment of the tool head 5 in the hole 21. These errors may be caused by errors in the sensor, calibration problems, calculation errors, etc. As a result, the tool head 5 may enter the hole 21 (assisted by the introduction groove) and then be constrained by the wall 22 of the hole 21. This is best illustrated in Figure 2(a), where the tool head is inserted along the initial insertion trajectory 37 having an axis off-center from the hole axis 51. As a result, the expandable collet 7 in the retracted configuration 11 contacts and is constrained by a portion of the wall 22.

[0061] Sensor 19 detects the constraint of the tool head 5 on the wall 22 (120) and accordingly transmits a sensor signal indicating this state to the controller 30. The controller 30 then receives these sensor signals (230) and determines the constraint of the tool head on the wall 22 (240). Accordingly, the controller transmits a control signal (250) to stop the robot insertion of the tool head 5 (122) and transmits an activation control signal (250) to activate the self-centering device 41 (130) to reorient and reposition the tool head 5 to the corrected alignment 43.

[0062] To facilitate the repositioning operation to the corrected alignment 43, the robotic drill system 1 may be switched to a compliant free-drive mode (124) so ​​that the force generated by activating the self-centering device 41 (130) allows the tool head 3 to move. In one embodiment of Figure 2(c), activating the self-centering device includes extending the expandable collet 7 of the tool head 5 toward the wall 22 of the hole 21. To provide a precise corrected alignment, this may include extending the expandable collet 7 until a force threshold is reached between the expandable collet 7 and the wall 22. This may be determined based on the collet sensor output of the collet sensor 53.

[0063] The modified alignment 43 may include positioning the tool head 5, thereby making the tool head axis 49 coaxial with the hole axis 51. This movement is best illustrated in the transition from Figure 2(b) to Figure 2(c). In this case, the expandable collet 7 (as the self-centering device 41) expands to its expanded configuration, so that the cylindrical outer surface of the expandable collet 7 substantially overlaps with the wall 22 of the hole 21. In Figure 2(c), the tool head 5 is shown in the modified alignment 43, where the tool head axis 49 is coaxial with the hole axis 51.

[0064] One or more self-centering device sensors (such as a collet sensor 53) may detect that the tool head 5 is in the corrected alignment 43 and may transmit the output signal of the corresponding self-centering device sensor to the controller 30. Upon receiving a sensor signal indicating the corrected alignment (245), the controller 30 transmits a deactivation control signal (246) to deactivate the self-centering device 41.

[0065] In the toolhead 5, the self-centering device 41 is deactivated (134). As shown in Figure 2(d), this may include configuring the expandable collet 7 into a retracted configuration 11.

[0066] The next step is to further insert the tool head 5 into the hole 21. To achieve this, the controller 30 is configured to return the robot manipulator arm 15 to drive mode (132). This allows for the selective activation of the robot actuator 17 to result in further insertion of the tool head 5.

[0067] The controller 30 is also configured to calculate an updated insertion trajectory 45 based on the corrected alignment 43 (260). As shown in Figures 4 and 6, this may include calculating the control signals required to advance the toolhead 5 along the current toolhead axis 49, which is coaxial with the hole axis 51 (136). To calculate the corrected alignment, the controller 30 may receive position sensor outputs representing the position and / or alignment of the toolhead 5 in the corrected alignment from one or more toolhead position sensors (262). The controller 30 may then calculate an updated insertion trajectory based at least in part on this required position sensor output. In some embodiments, this updated position sensor output can be used to recalibrate the robotic drill system 1.

[0068] The controller 30 transmits updated control signals (270) to selectively activate the robot actuator 17 (142) to drive the robot manipulator arm 15. This causes the tool head 5 to be inserted into the hole 21 along the updated insertion trajectory 45 (140). This is best illustrated in Figure 2(e), where the tool head 5 is inserted into the hole 21 with the expandable collet 7 retracted.

[0069] One or more toolhead sensors 55 detect the position or further movement of the toolhead 5 as it advances further along the updated insertion trajectory 45. The toolhead sensors 55 (such as the induction sensors or optical sensors described above) transmit a toolhead signal (144) indicating that the toolhead 5 has been inserted (144) into a designated position in the hole 21. In some embodiments, as shown in Figure 5, this includes the toolhead 5 reaching a designated depth in the hole 21. Upon receiving a toolhead sensor signal (275) indicating that the toolhead 5 is in a designated position 47, the controller 30 transmits a control signal to stop further activation (146) of the robot actuator 17 so that further insertion is stopped. The controller 30 also transmits an activation control signal (276) to activate (148) the toolhead self-centering device 41 to fix the toolhead 5 in a designated position relative to the hole 21.

[0070] In some embodiments, expanding the expandable collet 7 can retract the tool head 5 so that it moves further into the hole 21 of the drill template 23. In other embodiments, expanding the expandable collet 7 can result in retracting the tool head 5 so that it moves slightly away from the hole 21 of the drill template 23. The specified position can be offset to compensate for such movement so that the end effector 9 is positioned at a desired relative position within the hole 21 during firing.

[0071] In response to the tool head 5 being fixed in the specified position, the controller 30 further transmits an end effector control signal (280) to activate the end effector 9 of the tool head 5 (150).

[0072] This is best illustrated in Figure 2(f), in which an expandable collet 7 is in an expanded configuration 13 to secure the tool head 5 to the wall 22 of the hole 21, and the end effector 9 is activated to drill a hole in the workpiece 8. This may include the end effector 9 advancing further forward through the tool head axis 49 relative to the expandable collet 7 secured in the hole 21.

[0073] Once the end effector 9 has completed its operation within the hole, the robotic drill system 1 may withdraw the tool head 5 from the hole 21 and proceed to insert the drill template into another hole to perform the next operation on the workpiece 8.

[0074] Multiple clauses This disclosure includes exemplary embodiments as set forth below. Article 1. A tool head (5) having an expandable collet (7) and an end effector (9), wherein the expandable collet (7) is configured to expand between a retracted configuration (11) and an extended configuration (13) for insertion into a hole (21) of a drill template (23), A robotic manipulator arm (15) for supporting the tool head (5), At least one robot actuator (17) for moving the robot manipulator arm (15) to bring about robotic insertion of the tool head (5) directed into the hole (21) of the drill template (23), The drill template (23) comprises at least one sensor (19) for detecting the constraint of the expandable collet (7) in the hole (21), In response to the detection of constraint on the expandable collet (7) within the hole (21), the robotic insertion of the tool head (5) is stopped, and the expandable collet (7) is configured to expand into the expanded configuration (13) to center the end effector (9) within the hole (21). A robotic drilling system (1) in which the retracted diameter (27) of the expandable collet (7) in the retracted configuration (11) is at least 95% but less than 100% of the diameter of the hole (21) of the template hole. Article 2. The robot drill system (1) according to Clause 1, wherein, in response to detection of constraint on the expandable collet (7) in the hole (21), robot insertion is stopped, and the robot manipulator arm (15) and the at least one actuator (17) are switched to a compliant free-drive mode in which the robot manipulator arm is freely repositioned to a corrected alignment with respect to the hole by the force generated by extending (130) the expandable collet (7) of the tool head (5). Article 3. A robotic drilling system (1) according to Clause 1 or 2, further comprising a limited-precision sensor (33) for providing a limited-precision sensor feedback signal (35) to guide the insertion of the tool head (5) directed into the hole (21) along an initial insertion trajectory (37). Article 4. The limited-precision sensor (33) is a video camera or depth camera system, as described in Clause 3, for the robotic drilling system (1). Article 5. The aforementioned receding diameter (27) is 95% to 97% of the diameter of the template hole, 97% to 99% of the diameter of the template hole, or A robotic drilling system (1) according to any one of the clauses 1 to 4, wherein the diameter of the template hole is at least 99%, but less than 100%, within at least one of these ranges. Article 6. The robotic drilling system (1) according to any one of Clauses 1 to 5, wherein the tool head (5) includes an introduction groove (29) for assisting the insertion of the tool head (5) into the hole (21), and the introduction groove (29) includes an introduction edge (31) having an introduction diameter (34) less than the retracted diameter (27) and at least 75% of the diameter of the template hole. Article 7. The at least one sensor (19) for detecting restraint is, A sensor for detecting changes in current, voltage, and / or heat in at least one robot actuator (17), A force sensor for detecting at least one force in one or more of the tool head (5), the collet (7), the robot actuator (17), or the drill template (23), An accelerometer for detecting changes in the acceleration of the collet (7) or the tool head (5), and A robotic drilling system (1) according to any one of the clauses 1 to 6, comprising one or more sensors for detecting electrical conductivity or changes in capacitance between the collet (7) or the tool head (5) and the drill template (23). Article 8. The system further includes a collet sensor (53) for outputting a collet sensor output representing the force between the expandable collet (7) and the wall (22) of the hole (21), Configuring the expandable collet (7) into the expanded configuration (13) includes expanding the diameter of the expandable collet (7) until the collet sensor output reaches or exceeds a threshold, as described in any one of Clauses 1 to 7, for the robotic drill system (1). Article 9. A method of drilling using a robotic drilling system (1), To bring about robotic insertion of the tool head (5), the tool head (5) of the robotic drill (3) is inserted into the hole (21) of the drill template (23) along an initial insertion trajectory (37) using a robotic manipulator arm (15) moved by at least one robotic actuator (17) (110). To detect the constraint of the tool head on the wall (22) of the hole (21) (120), While inserting the toolhead (5) along the initial insertion trajectory (37), depending on the constraint of the toolhead (5) against the wall (22) of the hole (21), the robotic insertion of the toolhead (5) is stopped (122), and the self-centering device (41) of the toolhead (5) is activated (130) to reorient the toolhead (5) to a corrected alignment (43) of the toolhead axis (49) with respect to the hole (21). Inserting the tool head into the hole (21) along the updated insertion trajectory (45) (140), wherein the updated insertion trajectory is based on the modified alignment (43), and A method comprising activating (150) the end effector (9) of the tool head (5). Article 10. Depending on the constraint of the tool head (5) on the wall (22), the method further: Stopping the robot insertion of the tool head (5) directed towards the hole (21) along the initial insertion trajectory (37) (122), This includes switching the robot manipulator arm (124) to a compliant free-drive mode to facilitate the repositioning (43) of the tool head axis (49) to the modified alignment (43) of the hole (21) by the force generated by activating the self-centering device (41) (130) of the tool head (5), Following the activation of the self-centering device (41) of the tool head (5) to reposition the tool head (5) to the modified alignment with respect to the hole (21), the method further: The selective activation of at least one robot actuator (17) is configured to move the robot manipulator arm (15) to bring the tool head (5) into robotic insertion mode (132), and the robot manipulator arm (15) is configured to drive mode (132), and The drilling method according to Clause 9, comprising (134) deactivating the self-centering device of the tool head. Article 11. Following the activation (130) of the self-centering device of the tool head (5) in order to reposition the tool head (5) to the modified alignment with respect to the hole (21), the method further: This includes calculating (136) an updated control signal for inserting the tool head (5) along the updated insertion trajectory (45), Inserting the tool head into the hole along the updated insertion trajectory (140) The method according to Clause 10, comprising selectively activating the robot actuator (17) (142) in accordance with the updated control signal. Article 12. Inserting the tool head (5) into the hole (21) along the updated insertion track (45) is The process further includes inserting the tool head (5) into the designated position (47) (144), Depending on whether the tool head is positioned at the designated location (47), the method further: To stop the selective activation of the robot actuator (17) (146), and The drilling method according to Clause 11, comprising activating the self-centering device (41) of the tool head (5) to fix the tool head (5) in the designated position (47) when activating the end effector (9) of the tool head (5). Article 13. The drilling method according to any one of the clauses 9 to 12, wherein the modified alignment (43) of the tool head (5) with respect to the hole (21) includes ensuring that the tool head axis (49) of the tool head (5) is coaxial with the hole axis (51) of the hole (21). Article 14. Detecting the constraint of the tool head (5) on the wall (22) of the hole (21) (120) The force is detected in one or more of the self-centering device (41), the tool head (5), the robot actuator (17), or the drill template (23) of the robot drill (3), To detect electrical conductivity or changes in capacitance between the self-centering device (41) or the tool head (5) and the drill template, To detect changes in the acceleration of the self-centering device (41) or the tool head (5), The method according to any one of the claims 9 to 13, comprising detecting changes in current, voltage, and heat in the actuator or other components of the robot drill (3). Article 15. The method according to any one of the clauses 9 to 14, wherein activating the self-centering device of the tool head (5) (130, 148) includes extending the collet (7) of the tool head (5) toward the wall (22) of the hole (21). Article 16. The method according to Clause 15, wherein activating the self-centering device (130, 148) includes extending the collet (7) until a force threshold between the collet (7) of the tool head (5) and the wall (22) is reached or exceeded. Article 17. A non-transient computer-readable storage medium storing computer-readable program code, wherein, when executed by a processor, the program code is transmitted to the computer system, at least: To calculate the initial control signal (210) for the robot actuator (17) to insert the tool head of the robot drill toward the hole in the drill template along the initial insertion trajectory, To insert the tool head toward the hole along the initial insertion trajectory, a control signal is transmitted to the robot actuator (220), Receiving a sensor signal (230) that represents the constraint of the tool head (5) on the wall (22) of the hole (21), Based on the sensor signal, the constraint of the tool head on the wall (22) of the hole (21) is determined (240), and accordingly, an activation control signal is sent to activate the self-centering device (41) of the tool head (5) in order to reposition the tool head to the corrected alignment with respect to the hole (250). Based on the corrected alignment of the toolhead (5), calculate the updated insertion trajectory (260), To insert the tool head toward the hole along the updated trajectory, an updated control signal is transmitted to the robot actuator (270), and A non-transient computer-readable storage medium that causes the end effector control signal to be transmitted (280) in order to activate the end effector of the toolhead. Article 18. When executed by a processor, it further affects the computer system, The system is configured to receive position sensor signals from one or more position sensors that represent the position and / or alignment of the tool head in the modified alignment (262), Calculating an updated insertion trajectory (260) comprises the system calculating the updated insertion trajectory based on the position sensor signal of the tool head in the modified alignment, according to claim 17. Article 19. In the modified alignment described above, the tool head axis (49) is coaxial with the hole axis (51) of the hole. Calculating the updated insertion trajectory (260) (260) includes the system calculating the updated insertion trajectory along the tool head axis (49) of the centrally positioned tool head (5) in a non-transient computer-readable storage medium as described in Clause 18. Article 20. Calculating the initial control signal (210) for the robot actuator (17) is performed by the computer system, This includes receiving a limited-precision sensor feedback signal (35) from a limited-precision sensor (33) regarding the position or orientation of the tool head (5) relative to the hole (21) of the drill template (23), The initial control signal is at least in part based on the limited-precision sensor feedback signal (35) in a non-transient computer-readable storage medium as described in any one of clauses 17 to 19. Article 21. When executed by the aforementioned processor, the computer system further: Receiving an egocentering device sensor output from the egocentering device sensor (53) indicating that the tool head (5) is in the modified alignment (43) with respect to the hole (21) (245), and A non-transient computer-readable storage medium according to any one of the clauses 17 to 20, which causes the tool head (5) to transmit a deactivation control signal (246) to deactivate the self-centering device (41) of the tool head (5) in response to receiving the self-centering device sensor output indicating that the tool head (5) is in the modified alignment (43). Article 22. When executed by the aforementioned processor, the computer system further: The tool head sensor (55) receives a tool head sensor signal (275) indicating that the tool head (5) is in a specified position (47) within the hole (21), Depending on whether the tool head is positioned at the designated location, the system will transmit an activation control signal (276) to activate the self-centering device (41) of the tool head in order to fix the tool head at the designated position relative to the hole (21), A non-transient computer-readable storage medium according to any one of the clauses 17 to 21, which causes the computer system to transmit the end effector control signal (280) to activate the end effector of the tool head, depending on whether the tool head is fixed in the designated position relative to the hole.

[0075] The above disclosures may encompass multiple individual embodiments, each with its own specific utility. While each of these disclosures is disclosed in a preferred form, the specific embodiments disclosed and illustrated herein should not be taken restrictively, as numerous modifications are possible. Section headings, as used within this disclosure, are for structural purposes only. The subject matter of this disclosure includes all novel and non-obvious combinations and partial combinations of the various elements, features, functions, and / or characteristics described herein. The following claims specifically refer to certain combinations and partial combinations that are considered novel and non-obvious. Other combinations and partial combinations of features, functions, elements, and / or characteristics may be claimed in an application claiming priority from this application or a related application. Furthermore, such claims, whether broader, narrower, equal to, or different from the original claims, are considered to be within the scope of the subject matter of this disclosure.

[0076] Those skilled in the art should understand that numerous variations and / or modifications can be made to the embodiments described above without departing from the broad general scope of this disclosure. Therefore, these embodiments should be construed in all respects as illustrative and non-limiting.

Claims

1. a tool head (5) having an expandable collet (7) and an end effector (9), the expandable collet (7) configured to expand between a retracted configuration (11) for insertion into a hole (21) of a drill template (23) and an expanded configuration (13); a robot manipulator arm (15) for supporting said tool head (5); at least one robotic actuator (17) for moving the robotic manipulator arm (15) to effect robotic insertion of the tool head (5) directed into the hole (21) of the drill template (23); at least one sensor (19) for detecting binding of the expandable collet (7) within the hole (21) of the drill template (23); in response to detecting binding of the expandable collet (7) within the bore (21), robotic insertion of the tool head (5) is halted and the expandable collet (7) is configured to expand to the expanded configuration (13) to center the end effector (9) within the bore (21); A robotic drilling system (1), wherein a retracted diameter (27) of the expandable collet (7) in the retracted configuration (11) is at least 95% but less than 100% of the diameter of the hole (21) of a template hole.

2. 2. The robotic drilling system (1) of claim 1, wherein in response to detecting binding of the expandable collet (7) in the hole (21), robot insertion is stopped and the robot manipulator arm (15) and the at least one actuator (17) are switched (124) to a compliant free-drive mode in which the robot manipulator arm (15) is freely repositionable to a modified alignment (43) with respect to the hole (21) by forces generated by expanding (130) the expandable collet (7) of the tool head (5).

3. 3. The robotic drilling system (1) of claim 1 or 2, further comprising a limited precision sensor (33) for providing a limited precision sensor feedback signal (35) to guide insertion of the tool head (5) towards the hole (21) along an initial insertion trajectory (37).

4. The robotic drilling system (1) according to claim 3, wherein the limited precision sensor (33) is a video camera or a depth camera system.

5. The setback diameter (27) is (i) 95% to 97% of the diameter of the template hole; (ii) 97% to 99% of the diameter of the template hole; or (iii) at least 99% but less than 100% of the diameter of the template hole.

6. 2. The robotic drilling system of claim 1, wherein the tool head includes a lead-in groove to assist in insertion of the tool head into the hole, the lead-in groove including a lead-in edge having a lead-in diameter that is less than the setback diameter and at least 75% of the diameter of the template hole.

7. The at least one sensor (19) for detecting restraints comprises: a sensor for detecting current, voltage, and / or thermal changes in the at least one robotic actuator (17); a force sensor for detecting at least one force on one or more of the tool head (5), the collet (7), the robot actuator (17), or the drill template (23); an accelerometer for detecting changes in acceleration of the collet (7) or the tool head (5); and 2. The robotic drilling system (1) of claim 1, further comprising: a sensor for detecting a change in electrical continuity or capacitance between the collet (7) or the tool head (5) and the drill template (23).

8. a collet sensor (53) for outputting a collet sensor output representative of a force between the expandable collet (7) and a wall (22) of the hole (21); 2. The robotic drilling system (1) of claim 1, wherein configuring the expandable collet (7) to the expanded configuration (13) comprises expanding a diameter of the expandable collet (7) until the collet sensor output reaches or exceeds a threshold value.

9. A method (100, 200) for drilling using a robotic drill system (1), comprising: inserting the tool head (5) of the robotic drill (1) into the hole (21) of the drill template (23) along an initial insertion trajectory (37) using a robotic manipulator arm (15) moved by at least one robotic actuator (17) to effect robotic insertion of the tool head (5); Detecting the binding of the tool head (5) against the wall (22) of the hole (21); activating (130) a self-centering device (41) of the tool head (5) to reorient the tool head (5) into a corrected alignment (43) of the tool head axis (49) relative to the hole (21) in response to a constraint of the tool head (5) relative to the wall (22) of the hole (21) while inserting the tool head (5) along the initial insertion trajectory (37); Inserting (140) the tool head (5) into the hole (21) along an updated insertion trajectory (45), the updated insertion trajectory (45) being based on the revised alignment (43); and A method (100, 200) comprising actuating (150) an end effector (9) of the tool head (5).

10. In response to the constraint of the tool head (5) against the wall (22), the method (100, 200) further comprises: stopping (122) robotic insertion of the tool head (5) directed toward the hole (21) along the initial insertion trajectory (37); and switching (124) the robot manipulator arm (15) into a compliant free-drive mode to facilitate repositioning and moving the tool head (5) into the modified alignment (43) of the tool head axis (49) relative to the hole (21) by forces generated by activating (130) the self-centering device (41) of the tool head (5); Following activating (130) the self-centering device (41) of the tool head (5) to reposition (5) the tool head (5) into the modified alignment (43) with respect to the hole (21), the method (100, 200) further comprises: configuring (132) the robot manipulator arm (15) in a driven mode such that selective activation of at least one robot actuator (17) moves the robot manipulator arm (15) to effect robotic insertion of the tool head (5); and 10. The method (100, 200) of claim 9, comprising deactivating (134) the self-centering device (41) of the tool head.

11. Following activating (130) the self-centering device (41) of the tool head (5) to reposition (5) the tool head (5) into the modified alignment (43) with respect to the hole (21), the method (100, 200) further comprises: calculating (136) updated control signals for inserting the tool head (5) along the updated insertion trajectory (45); Inserting the tool head (5) into the hole (21) along the updated insertion trajectory (45) comprises: The method (100, 200) of claim 10, comprising selectively activating (142) the robot actuators (17) according to the updated control signals.

12. Inserting the tool head (5) into the hole (21) along the updated insertion trajectory (45) comprises: and inserting the tool head (5) into a designated location (47); In response to the tool head (5) being located at the designated position (47), the method (100, 200) further comprises: Deactivating (146) the selective activation of the robotic actuators (17); and 12. The drilling method (100, 200) of claim 11, comprising activating (148) the self-centering device (41) of the tool head (5) to fix the tool head (5) in the designated position (47) when activating the end effector (9) of the tool head (5).

13. The drilling method (100, 200) according to any one of claims 9 to 12, wherein the corrected alignment (43) of the tool head (5) with respect to the hole (21) comprises making a tool head axis (49) of the tool head (5) coaxial with a hole axis (51) of the hole (21).

14. Detecting the binding of the tool head (5) against a wall (22) of the hole (21) comprises: Detecting forces on one or more of the self-centering device (41) of the robotic drill (1), the tool head (5), the robot actuator (17), or the drill template (23); detecting a change in electrical continuity or capacitance between the self-centering device (41) or the tool head (5) and the drill template (23); Detecting a change in acceleration of the self-centering device (41) or the tool head (5); and detecting changes in current, voltage, heat in actuators or other components of the robotic drill (1).

15. 13. The method (100, 200) of claim 12, wherein activating (148) the self-centering device (41) of the tool head (5) comprises expanding the collet (7) of the tool head (5) towards the wall (22) of the hole (21) until a force threshold between the collet (7) of the tool head (5) and the wall (22) of the hole (21) is reached or exceeded.

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