Finger subassembly for robotic manipulator

Abstract

The present disclosure relates to a finger subassembly for a gripper assembly of a robotic manipulator, the finger subassembly comprising a base unit connectable to the gripper assembly by a mount and a high friction pad for contacting an article during manipulation of the article, the high friction pad being mechanically fixed to the base unit.

Description

Technical Field

[0001] The present disclosure relates to a finger sub - assembly for a type of gripper assembly used with a robotic manipulator. Aspects of the present invention relate to the finger sub - assembly, the gripper assembly, and the robotic manipulator.

Background Art

[0002] Robotic manipulators often include a gripper having opposing finger sub - assemblies for gripping an article during its operation. In most cases, the finger sub - assembly includes one or more high - friction pads for contacting the article. The high - friction pads are typically fixed to a base unit or its equivalent by an adhesive. This can cause problems as the adhesive can degrade over time, leading to the separation of the high - friction pads, which can be particularly problematic when the finger sub - assembly is required to pick up food products, as this would require a food - safe adhesive that meets strict regulatory requirements.

[0003] The present invention has been devised in view of such a background.

Summary of the Invention

[0004] Accordingly, in a first embodiment, a finger subassembly for a gripper assembly is provided, comprising a base unit connectable to the gripper assembly by a mount, and a high-friction pad for contacting an article during handling of the article, wherein the high-friction pad is mechanically fixed to or engaged with the base unit to prevent relative movement between them. Conventional finger subassemblies include a high-friction pad fixed to its base unit or equivalent by adhesive. This can cause problems as the adhesive may degrade over time, potentially leading to the detachment of the high-friction pad, and also necessitates a food-safe adhesive that must meet stringent regulatory requirements, which can be particularly problematic when the gripper assembly is required to pick up food products. The use of adhesive also makes the replacement of the high-friction pad more difficult. Therefore, instead of the chemical bond provided by adhesive, the finger subassembly according to a first embodiment is configured such that the high-friction pad is mechanically fixed to or engaged with the base unit to prevent relative movement between them.

[0005] Optionally, the base unit includes a notch that defines a recessed area into which a high-friction pad is slidably received.

[0006] Optionally, the notch and high-friction pad are configured to form an interlocking fit when the high-friction pad is inserted.

[0007] Optionally, high-friction pads are oversized for the notch in the lateral direction.

[0008] Optionally, high-friction pads are oversized relative to the notch in the longitudinal direction.

[0009] Optionally, the width of the notch and high-friction pad are tapered in the direction toward the tip of the base unit.

[0010] Optionally, the high-friction pad comprises a rigid plate overmolded with a high-friction material, and the base unit further comprises a longitudinal undercut into which a portion of the rigid plate is received when the high-friction pad is received in the notch.

[0011] Optionally, the end of the notch at the tip of the base unit includes a lateral undercut into which a portion of the rigid plate is received when the high-friction pad is received in the notch.

[0012] Optionally, the thickness of the high-friction pad is tapered so that a portion of the high-friction material and rigid plate is received in the lateral undercut when the high-friction pad is received in the notch.

[0013] The rigid plate is optionally perforated.

[0014] Optionally, the notch includes an open end into which a high-friction pad can be accommodated.

[0015] Optionally, the base unit is configured such that the open end of the notch is at least partially closed by the mount when the finger subassembly is connected to the mount.

[0016] Optionally, the tip of the base unit is shaped to protect the edge of the high-friction pad from impact during use.

[0017] Optionally, the base unit includes a bore through which bolts configured to fasten a finger subassembly to a mount can be accessed.

[0018] Optionally, the finger subassembly further comprises a frame unit, the frame unit and the base unit being configured to be fastened together to clamp a high-friction pad in place.

[0019] In a second aspect, a gripper assembly is provided that includes a finger sub-assembly according to the first aspect.

[0020] In a third aspect, a robot manipulator is provided that includes a gripper assembly according to the second aspect.

Brief Description of the Drawings

[0021] These and other aspects of the invention will be described by way of example only, with reference to the accompanying drawings. [Figure 1] FIG. 1 is a schematic view of a picking system for use according to the invention. [Figure 2] FIG. 2 is a side view of a gripper assembly for use with the system of FIG. 1. [Figure 3] FIG. 3 is an isometric view of a finger sub-assembly as shown in FIG. 2. [Figure 4a] FIG. 4a is an isometric view of the base unit of the finger sub-assembly of FIG. 3. [Figure 4b] FIG. 4b is a plan view of the base unit of FIG. 4a. [Figure 5a] FIG. 5a is a plan view of the high friction pad of the finger sub-assembly of FIG. 3. [Figure 5b] FIG. 5b is a side view of the high friction pad of FIG. 5a. [Figure 6] FIG. 6 is a side cross-sectional view of the finger sub-assembly of FIG. 3. [Figure 7] FIG. 7 is a longitudinal cross-sectional view of the finger sub-assembly of FIG. 3.

[0022] In the drawings, like features are indicated by like reference numerals as appropriate.

Modes for Carrying Out the Invention

[0023] In the following description, certain details are included to provide a full understanding of the disclosed examples. However, those skilled in the art will recognize that other embodiments may be practiced without one or more of these specific details, or with other components, materials, etc., and that structural modifications may be made without departing from the scope of the invention as defined in the appended claims. Furthermore, in the following description, any reference to any term having an implicit orientation is not intended to be limiting, but refers only to the orientation of the features shown in the appended drawings. In some examples, well-known features or systems such as processors, sensors, storage devices, network interfaces, fasteners, and electrical connectors are not shown or described in detail to avoid unnecessarily obscuring the description of the disclosed embodiments.

[0024] Unless the context requires otherwise, throughout this specification and the appended claims, the word “comprise,” and its variations such as “comprises” and “comprising,” should be interpreted in an open and comprehensive sense, meaning “including, but not limited to.”

[0025] Throughout this Specification, any reference to “one,” “an,” or “another” in the terms “embodiment,” “example,” etc., means that any particular reference feature, configuration, or characteristic described in relation to an embodiment, example, or implementation is included in at least one embodiment or implementation. Therefore, occurrences of the phrase “in one embodiment” or similar phrases in various places throughout this Specification do not necessarily all refer to the same embodiment. Furthermore, any particular feature, structure, or characteristic may be combined in any suitable manner in one or more embodiments, examples, or implementations.

[0026] Where used herein and in the accompanying claims, the user forms "a," "an," and "the" shall include plural references unless otherwise explicitly stated. It should be noted that the term "or" is generally used to include "and / or" unless explicitly stated otherwise.

[0027] Referring to Figure 1, an example of a type of picking system 100 suitable for use with the present invention is shown. The picking system 100 can form part of an online retail operation, such as an online grocery retail operation, but can also be applied to any other operation that requires picking and / or sorting of items or articles. In this example, system 100 includes a manipulator device 102 comprising a robotic manipulator 121. The robotic manipulator 121 is configured to pick an article 132 from a first location and place the article 132 in a second location. The manipulator device 102 is communicably coupled via a communication interface 104 to other components of system 100, such as one or more arbitrary operator interfaces 106, from which an observer can observe or monitor the operation of system 100 and the manipulator device 102. The operator interface 106 may include a WIMP interface and output displays of a description or dynamic representation of the manipulator device 102 in context or scenario. For example, the dynamic representation of the manipulator device 102 may include video and audio feeds, such as computer-generated animations. Examples of suitable communication interfaces 104 include wire-based network or communication interfaces, optical-based network or communication interfaces, wireless network or communication interfaces, or combinations of wired, optical, and / or wireless network or communication interfaces.

[0028] System 100 further comprises a control system 108 including at least one controller 110 that is communicably coupled to the manipulator device 102 and other components of System 100 via a communication interface 104. The controller 110 comprises a control unit or computing device having one or more electronic processors, which are embedded with a set of control instructions provided as processor-executable data, which, when executed, cause the controller 110 to issue actuation commands or control signals to the manipulator system 102, causing the robot manipulator 121 to perform various actions, such as identifying and manipulating an item 132. The one or more electronic processors may include at least one logic processing unit, such as one or more microprocessors, a central processing unit (CPU), a digital signal processor (DSP), a graphics processing unit (GPU), an application-specific integrated circuit (ASIC), a programmable gate array (PGA), or programmed logic units (PLUs). In some implementations, the controller 110 is a smaller processor-based device such as a mobile phone, single-board computer, or embedded computer, which is interchangeably called, or sometimes referred to as, a computer, server, or analyzer. The set of control instructions may be provided as processor-executable data associated with the operation of the system 100 and the manipulator device 102, contained in a non-temporary processor-readable storage device 112 that forms part of the system 100 and is accessible to the controller 110 via a communication interface 104. In some implementations, the storage device 112 includes two or more separate devices. The storage device 112 may include, for example, one or more volatile storage devices, such as random-access memory (RAM), and one or more non-volatile storage devices, such as read-only memory (ROM), flash memory, magnetic hard disk (HDD), optical disk, solid-state disk (SSD), etc.Those skilled in the art will understand that storage can be implemented in a variety of ways, including read-only memory (ROM), random access memory (RAM), hard disk drives (HDDs), network drives, flash memory, digital versatile disks (DVDs), any other form of computer and processor-readable memory or storage medium, and / or combinations thereof. Storage can be read-only or read-write, as required.

[0029] System 100 includes a sensor subsystem 114 comprising one or more sensors that detect, sense, or measure the conditions or state of the manipulator device 102 and / or the conditions of the environment or workspace in which the manipulator 121 operates, and generate or provide corresponding sensor data or information. The sensor information includes environmental sensor information representing the environmental conditions in the workspace of the manipulator 121, as well as information representing the conditions or state of the manipulator device 102, including various subsystems and their components, and the characteristics of the article 132 being manipulated. The acquired data is transmitted to the controller 110 via the communication interface 104, which can then instruct the manipulator 121 accordingly. Such information may include, for example, diagnostic sensor information useful in diagnosing the state or condition of the manipulator device 102 or the environment in which the manipulator 121 operates. For example, such sensors may include contact sensors, force sensors, strain gauges, vibration sensors, position sensors, attitude sensors, accelerometers, and the like. Such sensors may include one or more of the following: a camera or imaging device 116 (responding in the visible and / or invisible range of the electromagnetic spectrum, including infrared and ultraviolet light), radar, sonar, touch sensor, pressure sensor, load cell, microphone 118, weather sensor, chemical sensor, etc. In some implementations, diagnostic sensors include sensors for monitoring the status and / or health of onboard power supplies (e.g., battery array, ultracapacitor array, fuel cell array) within the manipulator device 102. In some implementations, one or more sensors include a receiver for receiving position and / or orientation information about the manipulator 121. For example, a GPS receiver for receiving Global Positioning System (GPS) data, two or more time signals for a controller 110 for creating position measurements based on data in the signals, such as time of flight, signal strength, or other data for achieving position measurement. Also, for example, one or more accelerometers forming part of the manipulator device 102 may be provided on the manipulator 121 to acquire inertial or orientation data in one, two, or three axes regarding its movement.

[0030] The manipulator 121 may be operated by a human operator at the operator interface 106. In human operator control or pilot mode, the human operator observes sensor data received from one or more sensors of the sensor subsystem 114, such as video, audio, or tactile data representations. The human operator then acts conditioned by the perception of the data representations and accordingly creates information or executable control commands to guide the manipulator 121. In pilot mode, the manipulator device 102 can execute control commands received from the operator interface 106 in real time (e.g., without additional delay) without considering other control commands based on the sensed information.

[0031] In some implementations, the manipulator device 102 operates autonomously; that is, a human operator does not create control commands in the operator interface 106 to direct the manipulator 121. The manipulator device 102 may operate in autonomous control mode by executing autonomous control commands. For example, the controller 110 may use sensor data from one or more sensors of the sensor subsystem 114, and the sensor data may be associated with operator-generated control commands from one or more times when the manipulator device 102 was in control mode, thereby generating autonomous control commands for subsequent use. For example, in autonomous mode, the manipulator device 102 may use deep learning techniques to extract features from the sensor data so that it autonomously recognizes features or states in its environment and the item 132 being manipulated, and accordingly executes a defined action, set of actions, task, or pipeline or sequence of tasks. In some implementations, the controller 110 autonomously recognizes features and / or conditions in the environment surrounding the manipulator 121, such as those represented by sensor data from the sensor subsystem 114 and one or more virtual items synthesized into the environment, and issues control signals to the manipulator device 102 to perform one or more actions or tasks in response to the presentation of these representations.

[0032] In some cases, the manipulator device 102 may be operated, controlled, or manipulated by a human operator at one time, while being autonomously controlled at another time. That is, it may operate in an autonomous control mode and then be changed to operate in a pilot mode (i.e., non-autonomous). In the other operating mode, the manipulator device 102 may replay or execute control commands previously executed in the human operator control (or pilot) mode. That is, the manipulator device 102 may operate without sensor data based on the replayed pilot data.

[0033] The manipulator device 102 further includes a communication interface subsystem 124, for example, a network interface device that is communicably coupled to a bus 126 and provides bidirectional communication with other components of the system 100 (e.g., a controller 110) via the communication interface 104. The communication interface subsystem 124 may be any circuit affecting bidirectional communication of processor-readable data and processor-executable instructions, such as a radio (e.g., a radio or microwave frequency transmitter, receiver, transceiver), a communication port, and / or associated controller. Suitable communication protocols include FTP, HTTP, web services, SOAP with XML, Wi-Fi® compliant, Bluetooth® compliant, cellular (e.g., GSM®, CDMA), etc.

[0034] The manipulator 121 is an electromechanical machine comprising one or more attachments, such as a robotic arm 120, and a gripper assembly or end effector 122 attached to the end of the robotic arm 120. The gripper assembly 122 is a device of complex design configured to interact with the environment to perform several tasks, including, for example, grasping, holding, releasably engaging, or otherwise interacting with an article 132. The manipulator device 102 further includes a motion subsystem 130 communicatively coupled to the robotic arm 120 and the gripper assembly 122. The motion subsystem 130 comprises one or more motors, solenoids, other actuators, linkages, drive belts, etc., which are operable to move the robotic arm 120 and / or the gripper assembly 122 within a range of motion in accordance with actuation commands or control signals issued by the controller 110. The motion subsystem 130 is communicatively coupled to the controller 110 via a bus 126.

[0035] The manipulator device 102 also includes an output subsystem 128 having one or more output devices, such as a speaker, light, or display, that enable the manipulator device 102 to transmit signals into the workspace for communication with an operator and / or another manipulator device 102.

[0036] Those skilled in the art will understand that the components of the manipulator device 102 may be modified, combined, divided, omitted, and so on. In some examples, one or more of the communication interface subsystem 124, the output subsystem 128, and / or the motion subsystem 130 may be combined. In other examples, one or more of the subsystems (e.g., the motion subsystem 130) may be divided into further subsystems.

[0037] Figure 2 shows an example of a gripper assembly 122 suitable for use with the manipulator 121 of Figure 1. In this example, the gripper assembly 122 comprises a list component 134 used to connect the assembly 122 to the manipulator 121. The list component 134 movably supports a link assembly, generally designated 136. The link assembly 136 comprises two pairs of link arms 138a, 138b driven by actuators housed within the list component 134. Each pair of link arms 138a, 138b are connected at their distal ends by a mount 140, which carries a finger subassembly 142.

[0038] Referring to Figure 3, the finger subassembly 142 comprises a base unit 144 connectable to the gripper assembly 122 by a mount 140, and a high-friction pad 146 defining a contact surface 147 for articles during handling. In conventional finger subassemblies, the high-friction pad is fixed to its base unit or equivalent by adhesive. This can cause problems as the adhesive can degrade over time, potentially leading to the separation of the high-friction pad, which can be particularly problematic if the gripper assembly 122 is required to pick up food products, as this would require a food-safe adhesive that must meet stringent regulatory requirements. The use of adhesive also makes replacing the high-friction pad more difficult. Therefore, instead of adhesive, the finger subassembly 142 of the present invention is configured such that the high-friction pad 146 is mechanically fixed to or engaged with the base unit 144, as opposed to a chemical bond provided by adhesive, to prevent relative movement between them. In one example, the finger subassembly 142 may include a frame unit that can be fastened to a base unit 144 to clamp a high-friction pad 146 in place. In the example shown in Figure 3, the base unit 144 includes a notch 148 that defines a recessed area 150 into which the high-friction pad 146 is received. In this example, the notch 148 and the high-friction pad 146 are configured to allow the high-friction pad 146 to be slidably received into the recessed area 150. This configuration avoids the use of adhesives and provides a simple method for removing and replacing the high-friction pad 146 as needed.

[0039] Referring to Figures 4a, 4b, 5a, and 5b, the width of the notch 148 is tapered along the long axis or longitudinal axis of the base unit 144 toward the tip 152 of the base unit 144 in order to facilitate the insertion and removal of the high-friction pad 146, and the high-friction pad 146 is similarly tapered, defining complementary shapes.

[0040] In this example, the high-friction pad 146 comprises a substantially rigid plate 154 overmolded with a high-friction compressible material 156 such as silicon. The rigid plate 154 may be made from a metal such as aluminum and comprises a number of perforations 157 to facilitate the overmolding process by allowing the liquefied high-friction material 156 to flow on both sides of the rigid plate 154. The area in which the high-friction material 156 is formed is smaller than the area of ​​the rigid plate 154, leaving exposed rims 158 extending along each longitudinal side of the high-friction pad 146. These rims 158 are configured to be received within longitudinal undercuts 160 formed within the sides of the notches 148 when the high-friction pad 146 is received into the recessed area 150, thereby precisely positioning the high-friction pad 146 within the notches 148 and further facilitating the insertion and removal of the high-friction pad 146.

[0041] Generally, the notch 148 and the high-friction pad 146 are configured to interfere or form a press-fit joint when the high-friction pad 146 is positioned within the notch 148, providing a friction connection that holds the high-friction pad 146 in place relative to the notch 148. For this purpose, with respect to the present example of the finger subassembly 142, the high-friction pad 146 is larger than the notch 148 in both the lateral and longitudinal directions, as shown in Figures 6 and 7, respectively, meaning that the high-friction pad 146 is under compression when held within the notch 148. Referring to Figure 7, the thickness of the high-friction pad 146 is tapered or reduced toward its end 162 positioned by the tip 152 of the base unit 144, defining a curved contact surface 147 in that region of the high-friction pad 146. This tapered end 162 includes a portion of the rigid plate 154 and is received by a lateral undercut 164 formed at the end of the notch 148. This compresses the high-friction material 156 within the lateral undercut 164, forming an interference or press-fit joint near the tip 152 of the base unit 144. The tip 152 is spherical or rounded to protect this joint from impact during use. The other end 166 of the high-friction pad 146 seats within the open end 168 of the notch 148. As shown in Figure 4a, the open end 168 is at least partially closed by the mount 140 when the mount 140 is fastened to the finger subassembly 142. The base unit 144 has a bore 170 through which bolts configured to fasten the finger subassembly 142 to the mount 140 are easily accessible. In this regard, the mount 140 functions to hold the high-friction pad 146 in place by applying a compressive force. These configurations, which have a tightly fitted connection between the high-friction pad 146 and the notch 148, ensure that the joint formed between them is minimal and has minimal depth and width. This reduces the area on the finger subassembly 122 where dust and bacteria can accumulate, which is an important consideration, especially if the gripper assembly 122 needs to pick up food items.

[0042] The foregoing description is provided for illustrative purposes only and is not intended to be exhaustive or to limit the invention to the exact form disclosed. It will be understood that modifications and changes can be made to the embodiments described without departing from the scope of the invention as defined in the appended claims. The invention described in the original claims of this application is listed below. [1] A finger subassembly for a gripper assembly, A base unit that can be connected to the gripper assembly by a mount, A finger subassembly comprising a high-friction pad for contacting an article during its operation, wherein the high-friction pad is mechanically fixed to the base unit to prevent relative movement between the base unit and the finger subassembly. [2] The finger subassembly according to [1], wherein the base unit includes a notch defining a recessed area in which the high-friction pad is to be received. [3] The notch and the high-friction pad are configured to form an interlocking fit when the high-friction pad is received therein, as described in [2]. [4] The finger subassembly according to [3], wherein the high-friction pad is oversized with respect to the notch in the lateral direction. [5] The finger subassembly according to [3] or [4], wherein the high-friction pad is oversized over the notch in the longitudinal direction. [6] The finger subassembly according to any one of [3] to [5], wherein the width of the notch and the high-friction pad are tapered toward the tip of the base unit. [7] The finger subassembly according to any one of [2] to [6], wherein the high-friction pad comprises a rigid plate overmolded with a high-friction material, and the base unit further comprises a longitudinal undercut into which a portion of the rigid plate is received when the high-friction pad is received in the notch. [8] The finger subassembly according to [7], wherein the end of the notch at the tip of the base unit includes a lateral undercut into which a portion of the rigid plate is received when the high-friction pad is received in the notch. [9] The finger subassembly according to [8], wherein the thickness of the high-friction pad is tapered so that the high-friction material and a portion of the rigid plate are received in the lateral undercut when the high-friction pad is received in the notch.

[10] The rigid plate is perforated, the finger subassembly according to any one of [7] to [9].

[11] The finger subassembly according to any one of [2] to

[10] , wherein the notch includes an open end into which the high-friction pad is received.

[12] The base unit is configured such that when the finger subassembly is connected to the mount, the open end of the notch is at least partially closed by the mount, as described in

[11] .

[13] The tip of the base unit is molded to protect the end of the high-friction pad from impact during use, as described in any one of [1] to

[12] , the finger subassembly.

[14] The finger subassembly according to any one of [1] to

[13] , wherein the base unit comprises a bore into which bolts configured to fasten the finger subassembly to the mount can be accessed.

[15] The finger subassembly according to [1], further comprising a frame unit, wherein the frame unit and the base unit are configured to be fastened together to clamp the high friction pad in place.

[16] A gripper assembly comprising a finger subassembly as described in any one of the items [1] through

[15] . A robotic manipulator having the gripper assembly described in

[17]

[16] .

Claims

1. A finger subassembly for a gripper assembly, A base unit that can be connected to the gripper assembly by a mount, The apparatus comprises a high-friction pad for contacting the article during its operation, wherein the high-friction pad is mechanically fixed to the base unit to prevent relative movement between it and the base unit. The base unit includes a notch that defines a recessed area in which the high-friction pad is received. The high-friction pad comprises a rigid plate overmolded with a high-friction material, and the base unit further comprises a longitudinal undercut into which a portion of the rigid plate is received when the high-friction pad is received in the notch, the finger subassembly.

2. The finger subassembly according to claim 1, wherein the end of the notch at the tip of the base unit includes a lateral undercut into which a portion of the rigid plate is received when the high-friction pad is received in the notch.

3. The finger subassembly according to claim 2, wherein the thickness of the high-friction pad is tapered so that when the high-friction pad is received in the notch, a portion of the high-friction material and the rigid plate is received in the lateral undercut.

4. The rigid plate is perforated, as described in claim 1, for the finger subassembly.

5. The finger subassembly according to claim 1, wherein the notch includes an open end into which the high-friction pad is received.

6. The finger subassembly according to claim 5, wherein the base unit is configured such that the open end of the notch is at least partially closed by the mount when the finger subassembly is connected to the mount.

7. The finger subassembly according to claim 1, wherein the tip of the base unit is molded to protect the end of the high-friction pad from impact during use.

8. A finger subassembly for a gripper assembly, A base unit that can be connected to the gripper assembly by a mount, The apparatus comprises a high-friction pad for contacting the article during its operation, wherein the high-friction pad is mechanically fixed to the base unit to prevent relative movement between it and the base unit. The base unit comprises a finger subassembly having a bore through which bolts configured to fasten the finger subassembly to the mount can be accessed.

9. The finger subassembly according to claim 8, wherein the base unit includes a notch defining a recessed area in which the high-friction pad is to be received.

10. The finger subassembly according to claim 9, wherein the notch and the high-friction pad are configured to form an interlocking fit when the high-friction pad is received therein.

11. The finger subassembly according to claim 10, wherein the high-friction pad is oversized with respect to the notch in the lateral direction.

12. The finger subassembly according to claim 10, wherein the high-friction pad is oversized over the notch in the longitudinal direction.

13. The finger subassembly according to claim 10, wherein the width of the notch and the high-friction pad are tapered in the direction toward the tip of the base unit.

14. A finger subassembly for a gripper assembly, A base unit that can be connected to the gripper assembly by a mount, The apparatus comprises a high-friction pad for contacting the article during its operation, wherein the high-friction pad is mechanically fixed to the base unit to prevent relative movement between it and the base unit. A finger subassembly further comprising a frame unit, wherein the frame unit and the base unit are configured to be fastened together to clamp the high-friction pad in place.

15. A gripper assembly comprising a finger subassembly according to any one of claims 1 to 14.

16. A robotic manipulator comprising the gripper assembly described in claim 15.

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