HK40000002A - Automated alignment of a testing system - Google Patents

Description

Automated alignment of test systems

Cross reference to related art

This application claims the benefit of U.S. provisional application serial No.62/365,225, filed on 21/7/2016, which is incorporated herein by reference in its entirety.

Technical Field

The present invention generally relates to an automated process for the alignment of a robotic effector for an indexing machine.

Background

As the capabilities of large-scale automation increase, more and more processes are being transitioned to unmanned environments. Laboratory test systems generally require clearly defined, repeatable results. This is because, in order to obtain a correct analysis, a large number of tests have to be performed, many of which are performed multiple times. Due to the repetitive nature, the testing process is perfectly suited to an automated process. However, due to the precise nature of the testing process, it may be difficult to accurately and consistently automate most of the steps involved. For example, the use of a pipetting probe to a sample tube on a disk-based track is a very repetitive task. However, it has proven difficult to fully automate the process due to the variables involved and the precision required.

Therefore, currently, some manual effort (e.g., alignment) is required to perform the multiple steps of the testing process. This typically includes: the operator visually inspects the system and uses a variety of tools (e.g., tool pins and plates) to adjust the pipette and sample tube. This is a slow and costly process when compared to typical automated systems. Therefore, there is a need for a faster, more efficient and more robust method of performing automation with respect to pipette sampling.

Disclosure of Invention

Accordingly, an embodiment provides an automated probe switch alignment system comprising: a robot arm; a probe attached to the robotic arm, having a sampling tip; a search tool attached to the robot arm, the search tool having a pressure sensitive tip; wherein the sampling tip of the probe is aligned with a predetermined target based on the alignment of the search tool; and wherein the search tool alignment is determined based on the force detected at the pressure sensitive tip.

Another embodiment provides a probe bounce sensor apparatus, comprising: a body having a top and a bottom; the body includes an aperture from top to bottom; the top of the body includes one or more sensing beams extending across the aperture; wherein the one or more sensing beams detect a position of an object passing through the aperture.

Another embodiment provides a method of automatically aligning an indexing machine having a robotic end effector, comprising: inserting a search tool into the aperture using the robotic arm, the search tool including a pressure sensitive tip; detecting a first position of a search tool within the aperture using a plurality of sensing beams; rotating the search tool 180 degrees using the robot arm; detecting a second position of the search tool within the aperture using the plurality of sensing beams; calculating a bounce amplitude and a bounce direction based on the first position, the second position, and the robot arm; inserting a search tool into the target using the robotic arm; determining the position of the search tool relative to the target using the pressure sensitive tip; and thereafter adjusting the position of the seek tool relative to the aperture and the target based on the determined position and the calculated bounce magnitude and bounce direction.

Drawings

The above aspects and other aspects of the present invention are best understood from the following detailed description when read in connection with the accompanying drawings. For the purpose of illustrating the invention, there is shown in the drawings embodiments which are presently preferred, it being understood, however, that the invention is not limited to the specific embodiments disclosed. Included in the drawings are the following figures:

fig. 1 is a schematic diagram of an exemplary system for automated alignment of an indexing machine having a robotic end effector.

Fig. 2 is a schematic diagram of an exemplary elongated search tool.

Fig. 3 is a schematic diagram of an exemplary elongated search tool with test tube ring slotted targets.

FIG. 4 is a schematic diagram of an exemplary shortened search tool.

FIG. 5 is a schematic diagram of an exemplary shortened search tool with test tube ring slotted targets.

FIG. 6 is a schematic diagram of an exemplary probe bounce sensor.

FIG. 7 is a schematic diagram of an exemplary probe bounce sensor in which the light beam is blocked by the probe tip.

FIG. 8 is a graphical representation of exemplary sensor outputs along a 360 circular boundary.

FIG. 9 is a graphical representation of exemplary sensor outputs along a 360 square boundary.

FIG. 10 is a schematic diagram of an exemplary measurement tool on a probe bounce sensor.

FIG. 11 is a graphical illustration of the calculation of the runout magnitude and runout direction.

Detailed Description

Embodiments herein relate to an automated system that may be used to align a diagnostic instrument of a robotic pipetting probe to a disc-based track in an indexing ring, a test tube, or a sample tube on a reagent pack. Advantageously, the automated system of embodiments provides a robust and efficient mechanism to ensure that the robotic pipetting process is consistent and accurate.

As discussed herein, the ability to ensure proper alignment and operation of the automated device during repeated testing is critical to ensure that the results are reproducible. However, current automated solutions either lack precision or are prohibitively expensive and therefore are not a suitable alternative for human operators. Because experiments require extreme precision, precise tools and complex procedures are required, which are performed manually by one or more trained field service technicians.

Thus, embodiments provide improvements via an extremely accurate alignment system to ensure proper interaction between the probe and the target. The automated alignment system may utilize a probe switch and/or a probe bounce sensor. By using one or more of these (i.e., probe switches and jitter sensors), embodiments can simplify the process while still achieving highly accurate and repeatable alignment.

Yet another embodiment may utilize long range high resolution probe switches. The high resolution probe switch may have a mechanical plunger at the tip for detecting a surface (i.e., a surface adjacent to a dedicated target). In another embodiment, the mechanical plunger may utilize a spring-loaded low force plunger to detect the surface of the target area. Additionally or alternatively, embodiments may include a rigid support system. The highly rigid support system may be able to more accurately detect the edge of the target. In another embodiment, a mechanical plunger as discussed herein may work in conjunction with a probe bounce sensor.

As described further herein, the probe bounce sensor can accurately measure the amplitude of the probe (e.g., in millimeters, centimeters, inches, etc.) and the orientation of the probe (e.g., radians, angles, etc.). This may allow embodiments to determine the flatness factor or amount of flatness error. Based on the determined straightness of the probe, yet another embodiment may take action to correct the straightness (e.g., adjust the magnitude or direction of the probe). By correcting for straightness, embodiments are in better position so that the true probe axis and tip are in proper alignment when moved to the center of the target or to a single indexing position within the ring set.

Referring now to fig. 1, embodiments may have one or more robotic arms with probes 101, 102, 103 (e.g., linear, rotational, etc.). The robotic arm probe allows embodiments to interface with a plurality of other test instruments 104 (e.g., rails, consumables, index rings, etc.). Another embodiment may also include a long-reach, high-resolution probe switch 105 with a spring-loaded, low-force plunger 105.

In one embodiment, an elongated (i.e., long) search tool 106 may be used. A non-limiting example of an elongated search tool 200 is shown in fig. 2. The long search tool 200 may also comprise a reagent probe arm 201, as shown in fig. 2. As shown in fig. 2, additional non-limiting components of long search tool 200 may be: sensor bracket 202, wide sensor (e.g., Optek) 203, e-clip 204, bracket compression spring 205, locking screw 206, rod 207, tube disk 208, rod compression spring 209, collar 210, flange bushing 211, hypotube 213, vertical tube 212, and straight bushing 214. Optek is a registered trademark of Optek-Danualt GmbH Corporation in the United states and other countries. One skilled in the art will appreciate that one or more of each of the above components may be included in an embodiment (e.g., two e-clips).

As shown in fig. 2, the maximum allowed rotational offset (r.o.) may be ± 0.33mm from the bottom of the collar 210 to the tip of the probe 215. Those skilled in the art will appreciate that the r.o. as shown in fig. 2 is merely a single non-limiting example of the r.o. limit, and in additional embodiments, the limit may be greater or lesser.

A long search tool 200 as shown in fig. 2 may require varying levels of force during different activities. Illustrative, non-limiting examples may be, for example, an initial force of 2.7 ounces, a sensor force of 3 ounces, and an over-travel force of 3.7 ounces. Thus, in one embodiment, varying levels of force may result in a total stroke of about 6 mm. In one non-limiting example, long search tool 200 may be about 2mm longer than the reagent probes to ensure proper alignment. Additionally, as shown in fig. 2, the search tool 200 may be removed by being withdrawn vertically upwards from the reagent probe arm 201.

In yet another embodiment, the alignment may be performed with respect to a circular target 301 on the indexing reagent pack tray. Additionally or alternatively, alignment may be performed with respect to a slotted target. Referring now to fig. 3, an embodiment such as an elongated search tool 200 may perform alignment via a slotted target system 300 (e.g., on an inner tube ring 303 and an outer tube ring 302).

In another embodiment, a shortened (i.e., short) search tool 400 may be used. A non-limiting example of a shortened search tool 400 is shown in fig. 4. As shown in fig. 4, the short search tool 400 may also include a sample probe 401. As shown in fig. 4, additional non-limiting components of the short search tool 400 may be: a locking bracket 402, a wide sensor (e.g., Optek wide sensor) 403, a rod 404, a tube disk 405, a rod compression spring 406, an e-clip 407, a collar 408, a bracket 409, a flange bushing 411, a hypotube 410, and a straight bushing 412. One skilled in the art will appreciate that one or more of each of the above components may be included in embodiments of short search tool 400 (e.g., two e-clips), as with a long search tool.

As shown in fig. 4, the maximum allowed r.o. may be ± 0.23mm from the bottom of the collar to the tip of the probe. It should be understood by those skilled in the art that r.o. as shown in fig. 2 is merely a single non-limiting example of an r.o. limit, and in additional embodiments, the limit may be greater or smaller.

A short search tool as shown in fig. 4 may require varying levels of force during different activities, illustrative non-limiting examples of which may be, for example, an initial force of 2.7 ounces, a sensor force of 3 ounces, and an over-travel force of 3.7 ounces. Thus, in one embodiment, varying levels of force may result in a total stroke of about 6 mm. In one non-limiting example, a short search tool may be about 2mm longer than the sample probe to ensure proper alignment. Additionally, as shown in fig. 4, the short search tool can be removed by detaching it vertically downward from the reagent probe arm.

Using a short search tool, embodiments can mount the short search tool to the sample probe arm and perform the alignment. In yet another embodiment, the alignment may be performed using a sample track disk. Additionally or alternatively, alignment may be performed for a tip tray indexer that includes consumable tips. Referring now to fig. 5, embodiments may perform alignment via a slotted target system 501 (e.g., on an inner and outer tube ring).

In one embodiment, as discussed herein, a probe bounce sensor 604 may be used to assist in the alignment process. For example, the probe bounce sensor 604 may have one or more sensing beams extending across an opening (i.e., an aperture) 605, e.g., as shown in fig. 6. The probe bounce sensor may have a body with a top and a bottom. In an embodiment, the one or more sensing beams may include a horizontal beam 603 and a vertical beam 602. The two-beam system shown in fig. 6 is only one possible embodiment, and a number of other embodiments (e.g., one beam, three beams, four beams, five beams, etc.) may also be used. The beam may be of any type known for beam detection, e.g., laser, infrared, optical, electro-optical, etc. As shown in fig. 6, an embodiment may have a probe bounce sensor with two opposing beams arranged orthogonally to each other. This allows embodiments to detect the offset amount of the pressure sensitive probe tip 601 with extremely high accuracy. Because the embodiment knows where the bottom collar of the probe arm is (see fig. 2 and 4), it can determine the insertion point relative to the probe holder via the robotic arm position.

Thus, in yet another embodiment, the sensor can detect the position of the pressure sensitive probe tip 601 as the pressure sensitive probe tip passes through the opening 605 of the probe bounce sensor 604. As shown in fig. 7, once the pressure sensitive tip 601 is low enough, it may intersect one or more beams 602, 603, indicating the position of the pressure sensitive probe tip 601 relative to the arm position. Thus, if the probe tip is moved horizontally in a single direction, it may block or unblock one of the beams 602. In one embodiment, if the pressure sensitive probe fails to successfully block all of the beam sensors, the pressure sensitive probe 601 may be prevented from traveling farther through the probe bounce sensor 604.

In one embodiment, it may be difficult, if not impossible, to remove or correct all alignment issues because both long and short search tools are mechanical systems with typical limitations, such as: bearing clearance, machining and flatness errors, and installation errors. Thus, the addition of a jitter sensor allows embodiments to combine multiple systems together to help ensure the most accurate and aligned probe possible. Correcting for jitter may allow embodiments to increase the ability of embodiments to find a target center. To correct for run-out, the amplitude and direction (typically referred to as run/mag/dir) need to be measured.

In one embodiment, the output of the probe bounce sensor may be a measurement of the distance from a pair of probe centers to the beams (e.g., D1, D2) along the X and Y coordinate systems of the sensor (e.g., defined at 45 ° with respect to both beams). In yet another embodiment, points at the boundary of the sensing region may be plotted at regular intervals in XY space (e.g., assuming XY scale 1 equals 100% of the boundary radial distance). Embodiments may then map the measured value of the distance to the beam (e.g., D1, D2) into D Ɵ space (e.g., beam distance contrast Ɵ sweep) for points along the boundary. The rendering may be done from 0 ° to 360 ° based on various increments (e.g., 1 °, 5 °, etc.). Referring now to fig. 8, in an embodiment, the circular boundary may take the form of a sinusoid having a typical shape with a 90 ° phase shift, for example as shown in fig. 8. Alternatively, a square boundary such as in fig. 9 adds a unique twist through a combination of a slanted line with a 45 ° node and a harmonic curve. This may be important because it is generally assumed that there will be a straight line between the peaks of the direction reversal. However, a straight line may only be obtained if the points along the boundary are equally spaced.

Since one of the keys to ensuring proper alignment is to know the run-out relative to a "perfectly straight tool" mounted in the tool holder, embodiments may employ the use of very straight measurement tools with equivalent mounting features. In an embodiment, the measurement tool may set a sensor "zero" point, which may then be transmitted anywhere throughout the sensing region, as it is determined via the mounting of the sensor relative to the robotic arm, for example as shown in fig. 9, so the zero point does not have to be at the beam intersection. Once calibrated, embodiments may replace the measurement tool with a seek tool (e.g., long or short) and repeat the process to determine the relative change in XY position, which will calculate the magnitude and direction of the run-out (i.e., run-out/magnitude/direction).

In another embodiment, no initial calibration is required. In general, the first calibration obtained using the measurement tool will almost always have some small, but meaningful, error when determining run-out/amplitude/direction. Thus, embodiments may be able to improve the process by: marked with visible scribe lines 1001, 1002, 1003 at 180 ° to the search tool (e.g., long and short search tools) and the tool holder mounted to the robot arm, such as shown in fig. 10.

First, embodiments may align the tool and tool holder wires and convey the probe past the run-out sensor. Embodiments may then rotate the tool 180 °, or until the tool is realigned to the tool holder line, and again conveyed past the run-out sensor. By performing the above process, embodiments are able to determine the relative change in XY position between two points (e.g., where the probe meets the bounce sensor at both 0 ° and 180 °), resulting in a line. This line can then be considered by the embodiment as a means of representing the diameter of the run-out circle. Based on the newly determined run-out circle diameter, a new "true zero" point can be projected by a theoretically straight tool as the midpoint of the determined diameter with respect to the tool holder neutral axis. Thus, after the second pass through the sensor, the run-out/amplitude/direction from the midpoint to the tool tip can be calculated. A non-limiting detailed example of the magnitude and direction of the jitter process using the probe jitter sensor and probe switch is set forth in fig. 11.

Although the present invention has been described with reference to exemplary embodiments, the present invention is not limited thereto. It will be understood by those skilled in the art that various changes and modifications may be made to the preferred embodiments of the present invention and that such changes and modifications may be made without departing from the true spirit of the invention. It is, therefore, intended that the appended claims be interpreted as covering all such equivalent variations as fall within the true spirit and scope of the invention.

Claims (20)

1. An automated probe switch alignment system, comprising:

a robot arm;

a probe attached to the robotic arm having a sampling tip; and

a search tool attached to the robotic arm, the search tool having a pressure sensitive tip,

wherein the sampling tip of the probe is aligned with a predetermined target based on the alignment of the search tool, an

Wherein the seek tool alignment is determined based on the force detected at the pressure sensitive tip.

2. The system of claim 1, further comprising a reagent pipette,

wherein the search tool is an elongated search tool, and

wherein reagent pipette alignment is based on alignment of the elongated search tool.

3. The system of claim 2, wherein the predetermined goal comprises one of: a circular target on the indexing reagent pack; a slotted target on the inner tube ring; and a slotted target on the outer tube ring.

4. The system of claim 2, further comprising a housing attached to the robotic arm,

wherein the elongated search tool is inserted through the housing attached to the robotic arm.

5. The system of claim 4, wherein the elongated search tool is removable from the housing.

6. The system of claim 1, further comprising a sample pipette, wherein the sample pipette alignment is based on an alignment of a shortened search tool.

7. The system of claim 6, wherein the predetermined goal comprises one of: a sample track disk; a tip tray indexer for consumable tips; an inner test tube ring; and an outer tube loop.

8. The system of claim 6, further comprising a housing attached to the robotic arm,

wherein the housing is configured to be inserted into the shortened search tool.

9. The system of claim 6, wherein the shortened search tool is removable from the housing.

10. The system of claim 1, wherein the pressure sensitive tip of the search tool extends lower than a sampling tip of the probe.

11. A probe bounce sensor apparatus, comprising:

a body having a top portion and a bottom portion,

the body includes an aperture from the top to the bottom,

the top of the body comprises:

one or more sensing beams extending across the aperture,

wherein the one or more sensing beams detect a position of an object passing through the aperture.

12. The apparatus of claim 11, wherein the one or more sensing beams comprise a plurality of sensing beams.

13. The apparatus of claim 12, wherein the plurality of sensing beams determine a position of the object in a horizontal plane based on a predetermined motion pattern of the object, and wherein a vertical alignment of the object is determined based on the position in the horizontal plane.

14. The apparatus of claim 11, wherein the object passing through the aperture is at least one of a probe and a search tool.

15. A method of automatically aligning an indexing machine having a robotic end effector, comprising:

inserting a search tool into the aperture using the robotic arm, the search tool comprising a pressure sensitive tip;

detecting a first position of the search tool within the aperture using a plurality of sensing beams;

rotating the search tool 180 degrees using the robotic arm;

detecting a second position of the search tool within the aperture using the plurality of sensing beams;

calculating a bounce magnitude and a bounce direction based on the first position, the second position, and the robotic arm;

inserting the search tool into a target using the robotic arm;

determining a position of the search tool relative to the target using the pressure sensitive tip; and

thereafter, the position of the search tool relative to the aperture and target is adjusted based on the determined position and the calculated magnitude and direction of the jump.

16. The method of claim 15, further comprising: inserting the search tool into a reagent pipette housing connected to the robotic arm.

17. The method of claim 16, further comprising:

removing the elongated search tool; and

a reagent pipette is inserted into the container,

wherein the alignment of the reagent pipette is based on the alignment of the elongated search tool.

18. The method of claim 15, further comprising: inserting a sample probe housing into the search tool.

19. The method of claim 18, further comprising:

removing the shortened search tool; and

a sample probe is attached to the sample probe,

wherein the alignment of the sample probe is based on the alignment of the shortened search tool.

20. The method of claim 16, further comprising: the sample probe housing is inserted into the second search tool.