Robot tool changer with integrated force / torque sensor

Abstract

This invention relates to a robotic tool changer having an integrated sensor configured to detect changes in applied force and torque. [Solution] The robot tool changer includes a master-side assembly coupled to a robot arm, and a tool-side assembly sandwiched and coupled between the master-side assembly and the tool used by the robot. A locking mechanism and a force / torque sensor are integrated into one of the master-side assembly and the tool-side assembly. The locking mechanism moves between a locked position and an unlocked position to lock and unlock the master-side assembly relative to the tool-side assembly. The force / torque sensor includes a sensing structure that elastically deforms in response to an applied force, and a transducer fixed to the sensing structure. The transducer transmits an electrical signal representing the magnitude and direction of the detected applied force to a measuring circuit.

Description

Technical Field

[0004] , , ,

[0001] The present disclosure generally relates to a tool changer for robotic applications, and more particularly to a robotic tool changer having an integrated sensor configured to detect changes in forces and torques applied to the tool changer.

Background Art

[0002] Industrial robots have become an indispensable component in modern manufacturing. When transferring semiconductor wafers from one process chamber to another within a cleanroom, or when cutting and welding steel materials on the floor of an automobile manufacturing plant, robots perform many manufacturing operations in harsh environments with high precision and high reproducibility without fatigue. In many cases, a robotic arm or a tool attached thereto may contact a workpiece. In such cases, it is necessary to closely monitor the forces and / or torques applied as a result of the contact. Therefore, force / torque sensors are an important component in many robotic systems.

[0003] The background art section of this document is provided to situate the embodiments of the present disclosure in a technical and operational context and to assist those skilled in the art in understanding its scope and utility. The approaches described in the background art section are pursuable, but are not necessarily approaches that have been previously devised or pursued. Unless expressly so specified, no description contained in the background art section is admitted to be prior art solely by virtue of its inclusion herein.

Summary of the Invention

[0005] According to one or more embodiments described and claimed herein, a robotic tool changer having a master-side assembly and a tool-side assembly comprises an integrated force / torque (F / T) sensor and a locking mechanism. In one embodiment, the locking mechanism and the F / T sensor are integrated into the master-side assembly, and in another embodiment, the locking mechanism and the F / T sensor are integrated into the tool-side assembly. The locking mechanism moves between a locked position and an unlocked position, connecting and separating the master-side and tool-side assemblies, respectively. The F / T sensor, on the other hand, detects an applied force and transmits an electrical signal representing the magnitude and direction of the force to a measuring circuit. However, regardless of the embodiment, the robotic tool changer of this disclosure may be actuated by a robot, actuated by a tool stand, actuated manually, actuated magnetically, actuated pneumatically, or actuated electrically.

[0006] In some embodiments, the integrated F / T sensor is independent of both the master-side and tool-side assemblies and includes separate components. In such cases, the F / T sensor is coupled to either the master-side assembly or the tool-side assembly. When integrated to the master-side assembly, the F / T sensor is positioned between the master-side assembly and the robot arm and is directly coupled to both the master-side assembly and the robot arm. However, when integrated to the tool-side assembly, the integrated F / T sensor is positioned between the tool-side assembly and the tool used by the robot and is directly coupled to both the tool-side assembly and the tool. In other embodiments, the integrated F / T sensor and the master-side or tool-side assembly into which it is integrated are manufactured from a single metal or metal alloy to form a single component.

[0007] Furthermore, the F / T sensor includes a plurality of elastically deformable sensing structures specifically configured to elastically deform when a force is applied to the robot tool changer. Each sensing structure, or "beam," further includes a pair of transducers mounted on its surface on either side of a neutral axis that bisects the sensing structure. During operation, each transducer detects the deformation of the mounted sensing structure due to the applied force. Upon such detection, each transducer transmits a corresponding electrical signal to a measuring circuit representing the magnitude and direction of the detected applied force. This embodiment can use any number and / or different types of F / T sensors configured to operate according to various techniques. However, in one or more embodiments, the integrated (one-piece) F / T sensor can be one or more of strain gauges, capacitive sensors, surface acoustic wave (SAW) sensors, fiber Bragg grating (FBG) sensors, optical sensors, or any combination thereof.

[0008] Accordingly, in one embodiment, the present disclosure relates to a robotic tool changer comprising a master-side assembly and a tool-side assembly coupled to a robotic arm. The tool-side assembly has a first side coupled to the master-side assembly and a second opposite side coupled to the one or more tools used by the robot. Furthermore, both a locking mechanism and a force / torque sensor are integrated into one of the master-side assembly and the tool-side assembly. The locking mechanism is configured to move between a locked position and an unlocked position to couple and separate the master-side and tool-side assemblies, respectively. The force / torque sensor comprises one or more sensing structures configured to deform elastically in response to an applied force, and one or more transducers attached to the one or more sensing structures. Each transducer transmits an electrical signal representing the magnitude and direction of the applied force to a measuring circuit.

[0009] In another embodiment, the disclosure provides a master-side assembly for a robotic tool changer. As described above, the master-side assembly is coupled to both the robotic arm and the tool-side assembly and further integrates both a locking mechanism and an F / T sensor. The locking mechanism moves between a locked position and an unlocked position to couple and uncouple the master-side assembly to and from the tool-side assembly of the robotic tool changer, respectively. The F / T sensor comprises one or more sensing structures configured to deform elastically in response to an applied force, and one or more transducers attached to the one or more sensing structures. Each of the one or more transducers is configured to transmit an electrical signal to a measuring circuit representing the magnitude and direction of the detected applied force.

[0010] Another embodiment of the present disclosure relates to a tool-side assembly for a robotic tool changer. The tool-side assembly in this embodiment is configured to couple with a master-side assembly of the robotic tool changer and with one or more tools used by the robot. The tool-side assembly also includes an integrated locking mechanism and an F / T sensor. The locking mechanism is configured to move between a locked position and an unlocked position to couple and separate the tool-side assembly from the master-side assembly of the robotic tool changer. The F / T sensor comprises one or more sensing structures that elastically deform in response to an applied force, and one or more transducers attached to the one or more sensing structures. Each transducer is configured to transmit an electrical signal to a measuring circuit representing the magnitude and direction of the applied force it has detected. [Brief explanation of the drawing]

[0011] This disclosure will be described in more detail below with reference to the accompanying drawings, which illustrate embodiments of the disclosure. However, this disclosure should not be construed as being limited to the embodiments shown herein. Rather, these embodiments are provided to ensure that the disclosure is thorough and complete and to fully convey the scope of the disclosure to those skilled in the art. The same numbers refer to the same elements throughout.

[0012] [Figure 1] Figure 1 is a plan view showing a robotic tool changer having an integrated force / torque (F / T) sensor according to an embodiment of the present disclosure.

[0013] [Figure 2] Figure 2 is a perspective view showing a robotic tool changer having an integrated F / T sensor configured according to an embodiment of the present disclosure.

[0014] [Figure 3] Figure 3 is a perspective view showing a robotic tool changer having an integrated F / T sensor configured according to an embodiment of the present disclosure.

[0015] [Figure 4A] , [Figure 4B] Figures 4A and 4B are perspective and plan views of the master-side assembly of an F / T sensor configured according to an embodiment of the present disclosure.

[0016] [Figure 5A] , [Figure 5B] Figures 5A and 5B are perspective and plan views of the tool-side assembly of an F / T sensor configured according to an embodiment of the present disclosure.

[0017] [Figure 6A] , [Figure 6B]Figures 6A-6B are perspective views showing the annular color of the master-side assembly and the bearing race of the tool assembly, respectively, configured according to an embodiment of the present disclosure.

[0018] [Figure 6C] Figure 6C is a perspective view showing the annular color and the bearing race according to an embodiment of the present disclosure, and further showing a state where the rolling member included in the hole (bore) formed in the annular color contacts the inclined surface of the notch of the bearing race.

[0019] [Figure 7] Figure 7 is a schematic view of a locking mechanism showing a series of rolling members that contact the inclined surfaces on the opposite sides of various notches of the bearing race according to an embodiment of the present disclosure.

[0020] [Figure 8A] Figure 8A is a plan view of a force / torque sensor according to an embodiment of the present disclosure.

[0021] [Figure 8B] Figure 8B is an enlarged view of the detection structure of the F / T sensor shown in Figure 8A.

[0022] [Figure 9A] Figure 9A is a perspective view showing a pair of strain gauges wire-bonded to a printed circuit board (PCB) according to an embodiment of the present disclosure.

[0023] [Figure 9B] Figure 9B is a perspective view of a pair of strain gauges surface-mounted on a flexible circuit board according to an embodiment of the present disclosure.

[0024] [Figure 10A] Figure 10A is a cross-sectional view and a functional circuit diagram of a quarter-bridge circuit topology of a strain gauge on a detection structure according to an embodiment of the present disclosure.

[0025] [Figure 10B] Figure 10B is a cross-sectional view and a functional circuit diagram of the X-connected half-bridge circuit topology of a strain gauge on a sensing structure according to an embodiment of the present disclosure.

[0026] [Figure 10C] Figure 10C is a cross-sectional view and a functional circuit diagram of a half-bridge circuit topology having inverted excitation polarity according to an embodiment of the present disclosure.

[0027] [Figure 11A] Figure 11A is a plan view of an F / T sensor according to an embodiment of the present disclosure, in which a plurality of strain gauge pairs are fixed to the upper surface of each detection structure.

[0028] [Figure 11B] Figure 11B is an enlarged view of one detection structure of the F / T sensor in Figure 11A, with a functional circuit diagram showing a half-bridge topology according to an embodiment of the present disclosure superimposed on it.

[0029] [Figure 12] Figure 12 is a plan view of an F / T sensor having a meandering, deformable sensing structure according to an embodiment of the present disclosure.

[0030] [Figure 13] Figure 13 is a plan view of an F / T sensor having a meandering, deformable sensing structure according to another embodiment of the present disclosure.

[0031] [Figure 14] Figure 14 is a perspective view of the meandering, deformable sensing structure of the F / T sensor shown in Figure 13.

[0032] [Figure 15] Figure 15 is a plan view of an F / T sensor having a meandering, deformable sensing structure according to another embodiment of the present disclosure.

[0033] [Figure 16]Figure 16 is a plan view of an F / T sensor having a spiral deformable sensing structure according to an embodiment of the present disclosure.

[0034] [Figure 17] Figure 17 is a perspective view of an F / T sensor having a vertically positioned (vertically oriented) deformable sensing structure according to an embodiment of the present disclosure. [Modes for carrying out the invention]

[0035] For the sake of brevity and clarity, this disclosure will be described primarily by reference to its representative embodiments. Many specific details are provided in the following description to fully understand this disclosure. However, it will be readily apparent to those skilled in the art that this disclosure can be implemented without being limited to these specific details. In order to avoid unnecessarily obscuring this disclosure, well-known methods and structures are not described in detail.

[0036] Looking at the drawings, Figure 1 shows an embodiment of a robotic tool changer 10 having both an integrated force / torque (F / T) sensor and an integrated locking mechanism, according to an embodiment of the present disclosure. As shown in Figure 1, this embodiment of the robotic tool changer 10 includes a master-side assembly 20, a tool-side assembly 30, an integrated locking mechanism 40, and an integrated F / T sensor 80, etc.

[0037] The master-side assembly 20 is configured to connect to the robot arm R, and the tool-side assembly 30 is configured to connect to one or more tools T available to the robot. Furthermore, the master-side and tool-side assemblies 20 and 30 are configured to align directly with each other and to be releasably connected. To align the master-side assembly 20 at the end of the robot arm R with the tool-side assembly 30 attached to the desired tool T (usually placed in a tool holder), the robot controller (not shown) instructs the master-side assembly 20 to mechanically connect to the tool-side assembly 30, thereby attaching the tool T to the robot. Similarly, once the tool T is safely placed in the tool stand after robot operation, the robot controller instructs the master-side assembly 20 to detach from the tool-side assembly 30, thereby allowing the robot to move and attach to another tool T.

[0038] In some robotic operations, for example, when the robotic tool is rarely or never changed, a manually operated robotic tool changer is safely used with the industrial robot. In such situations, the robotic arm R is typically stopped in a "safe" position. Its automatic operation is disabled while a person is attaching or detaching the tool T. Both automatically and manually operated robotic tool changers facilitate the supply of utilities such as electric current, pneumatics, hydraulic fluid, and cooling water to the tool T, and the transfer of data from some tool T to the robotic controller.

[0039] In this embodiment, the locking mechanism 40 is configured to move between a locked position and an unlocked position in response to the rotational movement of a lock lever 42, which is formed as a lever, and has the function of locking and unlocking the master-side and tool-side assemblies 20 and 30 to each other. The locking mechanism 40 will be described in more detail later. However, generally, when the lock lever 42 is rotated toward the robot tool changer 10, the master-side and tool-side assemblies 20 and 30 are locked together. In this locked position, the locking mechanism 40 significantly reduces or minimizes undesirable movements such as torsional play around the z-axis of the robot tool changer 10, thereby improving torsional rigidity. When the lock lever 42 is rotated toward the opposite direction away from the robot tool changer 10, the master-side and tool-side assemblies 20 and 30 are unlocked, and the assemblies 20 and 30 can be freely separated.

[0040] The integrated F / T sensor 80 may be located in different positions on or inside the robot tool changer 10, depending on the embodiment. Thus, as will be described in more detail below, this disclosure considers both “single-body” and “dual-body” embodiments. For example, in the “dual-body” embodiment, the integrated F / T sensor 80 is an independent component separate from both the master-side and tool-side assemblies 20, 30, and is releasably coupled / connected to either the master-side assembly 20 or the tool-side assembly 30 via one or more mechanical fasteners. When coupled to the master-side assembly 20, the F / T sensor 80 is located between the master-side assembly 20 and the tip of the robot arm R. Furthermore, the F / T sensor 80 is in direct contact with the tip of the robot arm R, and the surface of the F / T sensor 80 is in direct contact with the surface of the robot arm R. However, when coupled to the tool-side assembly 30, the F / T sensor 80 is located between the tool-side assembly 30 and one or more tools T used by the robot. Furthermore, in this embodiment, the F / T sensor 80 may be in direct contact with the tool T.

[0041] In the "single-body" embodiments, the F / T sensor 80 is an integral component of either the master-side assembly 20 or the tool-side assembly 30. In these embodiments, the integrated F / T sensor 80 is not a separate component independent of the master-side and tool-side assemblies 20, 30. Nor is it coupled to the master-side or tool-side assemblies 20, 30 via mechanical fasteners as described above. Rather, either the master-side assembly 20 or the tool-side assembly 30 is manufactured to include the integrated F / T sensor 80. For example, the F / T sensor 80 is machined into the master-side or tool-side assembly 20, 30 during the manufacturing process, and the F / T sensor 80, together with the locking mechanism 40 and the machined master-side or tool-side assembly 20, 30, forms an integral component.

[0042] In such “single-body” embodiments, the master-side or tool-side assemblies 20, 30 and the integrated F / T sensor 80 may be manufactured from a single metal or metal alloy using any technique known in the art. However, those skilled in the art will readily understand that the disclosure is not limited to simply machining the master-side or tool-side assemblies 20, 30 to include the integrated F / T sensor 80. For example, in other embodiments, the F / T sensor 80 and the master-side or tool-side assemblies 20, 30 may be manufactured separately as independent components and then joined by welding or other means to form a single, integrated member.

[0043] It should be noted that in the context of this embodiment, the term “integrated” means that separate or independent components, such as the F / T sensor 80, the locking mechanism 40, and either the master-side assembly 20 or the tool-side assembly 30, are combined into a harmonious and interconnected whole. The term “unitary” means that the F / T sensor 80, the locking mechanism 40, and the master-side or tool-side assembly 20, 30 into which the F / T sensor 80 and the locking mechanism 40 are integrated are not physically separable components. This is regardless of whether the F / T sensor 80, the locking mechanism, and the master-side or tool-side assembly 20, 30 into which they are integrated are manufactured from a single metal or metal alloy (e.g., by machining) or are manufactured separately and then joined together to form a single unit.

[0044] Furthermore, this disclosure uses the terms “master” and “tool” to refer to specific components of the robotic tool changer 10. However, in certain applications, the mounting of these components may be reversed. Therefore, the terms “master” and “tool” as used herein are for reference only.

[0045] Figure 2 shows a dual-body embodiment of the robot tool changer 10 as seen from the master-side assembly 20. In this embodiment, the F / T sensor 80 comprises a central hub 82 and spaced interfaces 84 arranged in a ring around the central hub 82. Both the central hub 82 and the interfaces 84 each have a number of through-holes 86, 88. Each through-hole 86 is sized and shaped to receive mechanical fasteners such as bolts, mechanically coupling the F / T sensor 80 to the master-side assembly 20, thereby integrating the F / T sensor 80 with the master-side assembly 20. Similarly, each through-hole 88 of the interfaces 84 is sized and shaped to receive mechanical fasteners that mechanically coupling the F / T sensor 80 to the tip of the robot arm R. Thus, the integrated F / T sensor 80 of this embodiment not only has the function of detecting and reporting changes in force and / or torque applied to the robot tool changer 10, but is also configured to mechanically couple directly to the robot arm R, and functions as a mounting interface that releasably connects the master-side assembly 20 of the robot tool changer 10 to the tip of the robot arm R.

[0046] The F / T sensor 80 also comprises a plurality of elastically deformable sensing structures, also referred to here as “beams” 90a, 90b, 90c, and one or more transducers 92a, 92b, 92c, respectively, fixed to one corresponding surface of each beam 90a, 90b, 90c. Although such orientation is not particularly required in this disclosure, in this embodiment, each beam 90a, 90b, 90c extends radially outward from the central hub 82 and connects to the inner surface of the interface 84. In other embodiments, as will be shown in more detail later, the beams 90a, 90b, 90c extend perpendicularly between the interface 84 and the surface of the master-side assembly 20.

[0047] During operation, each beam 90a, 90b, and 90c is subjected to a load and deforms. Each transducer 92a, 92b, and 92c is, for example, a foil or semiconductor / piezoresistive strain gauge that detects the strain on beams 90a, 90b, and 90c caused by the applied force. Such strain detection can be achieved, for example, by detecting changes in resistance as the load that deforms beams 90a, 90b, and 90c changes. Thus, in this embodiment, each transducer 92a, 92b, and 92c uses a Wheatstone bridge to convert the changes in resistance detected by transducers 92a, 92b, and 92c into changes in voltage. The changes in voltage are then converted into electrical signals for output to a processing circuit, such as a measurement circuit.

[0048] According to this disclosure, the electrical signals generated by transducers 92a, 92b, and 92c may be analog voltage signals or digital signals generated, for example, using an analog-to-digital signal converter. However, regardless of their specific form, the electrical signals generated by transducers 92a, 92b, and 92c may represent calculated forces and / or torques or may simply be raw signal data sent to a processing circuit for use in calculating these forces and / or torques.

[0049] In this embodiment, each beam 90a, 90b, and 90c extends between the central hub 82 and the surface of the side wall of the interface 84. However, the central hub 82 is separated from the interface 84 using one of two methods. The first method involves machining the elastically deformable beams 90a, 90b, and 90c, and around the central hub 82, effectively "cutting out" one or more separation sections 94. In this embodiment, there are three such separation sections 94, but there may be more or fewer separation sections 94 as needed or desired. The second method uses the interface 84 as a separate body specifically designed to be fixed directly to the master-side assembly 20 of the robot tool changer 10. This separate body is designed to integrate seamlessly with the master-side assembly 20 and the robot arm R, ensuring a unified and functional assembly with reduced stack height compared to the master-side assembly 20 and interface 84 alone.

[0050] As described above, transducers 92a, 92b, and 92c may be equipped with foil or semiconductor / piezoresistive strain gauges to detect deformation of beams 90a, 90b, and 90c under load. However, those skilled in the art will readily understand that this embodiment is not limited to these types of strain gauges. Detection based on deformation can also be obtained from distance detection in the form of capacitive sensors, SAW (surface acoustic wave), FBG (fiber Bragg grating), or optical sensors. In particular, in the case of capacitive sensors, the sensing structure flexes in a direction under load. Non-contact capacitive sensors can detect changes in capacitance due to changes in the gap between them. In the case of SAW / FBG / optical sensing elements, changes in distance pick up an analog signal, which is processed into force and torque resolved into digital or analog signals.

[0051] As those skilled in the art will understand, the number of elastically deformable sensing structures (e.g., beams 90a, 90b, 90c) and / or transducers 92a, 92b, 92c shown in Figure 2 is merely illustrative. However, typically an F / T sensor 80 configured according to this embodiment has at least three beams 90a, 90b, 90c, but may have more (e.g., up to six). Similarly, while an F / T sensor 80 typically has at least one transducer 92 fixed to each beam 90, multiple transducers 92 can be fixed to each beam 90. As seen in later embodiments, for example, any beam 90a, 90b, 90c of an F / T sensor 80 configured according to this disclosure may have two or more transducers 92 fixed to its surface.

[0052] Figure 3 shows another dual-body embodiment of the robot tool changer 10 having an integrated F / T sensor 80, as seen from the tool-side assembly 30. In particular, in this embodiment, the tool-side assembly 30 and the F / T sensor 80 are manufactured as separate, independent components and then mechanically joined together using one or more mechanical fasteners. As shown in Figure 3, the structure of the F / T sensor 80 integrated with the tool-side assembly 30 differs from the F / T sensor 80 integrated with the master-side assembly 20 shown in Figure 2. Specifically, the F / T sensor 80 in Figure 3 includes a central hub 96 formed as a ring surrounding and defining a central chamber 100 configured to receive at least a portion of the tool T used by the robot. Furthermore, the F / T sensor 80 in Figure 3 also includes an interface 98 formed as a concentric ring spaced apart from the central hub 96 and arranged in a ring around the central hub 96. Multiple through-holes 88 formed in the interface 98 allow the F / T sensor 80 and the tool-side assembly 30 into which it is integrated to be securely and mechanically fastened to the desired tool used by the robot.

[0053] The central hub 96 is separated from the interface 98 by either effectively cutting out the separation section 94 by machining around the elastically deformable beams 90a, 90b, and 90c, or by designing the F / T sensor 80 to be directly coupled to the tool-side assembly 30 of the robot tool changer 10. In the latter method, the interface 98 comprises a separate body specifically designed to be directly fixed to the tool-side assembly 30 of the robot tool changer 10. This separate body is designed to integrate seamlessly with the tool-side assembly 30 and the robot arm R, thereby ensuring a unified and functional assembly with reduced stack height compared to the case of the master-side assembly 20 and interface 98 alone. However, regardless of its structure, the F / T sensor 80 integrated with the tool-side assembly 30 shown in Figure 3 provides the same or similar functionality as the F / T sensor 80 integrated with the master-side assembly 20 shown in Figure 2. In other words, the deformation of beams 90a, 90b, and 90c under load is detected, and the tool-side assembly 30 of the robot tool changer 10 is safely attached to the desired tool to be used by the robot.

[0054] As stated above, this disclosure is not limited to dual-body implementations. Rather, this disclosure also provides single-body embodiments in which the integrated F / T sensor 80 and locking mechanism 40 are integrated into either the master-side assembly 20 or the tool-side assembly 30 to form a single (unitary) member. Figures 4A and 4B are perspective and plan views, respectively, of such a single (unitary) embodiment relating to the master-side assembly 20. In particular, the master-side assembly 20 and the integrated F / T sensor 80 are manufactured from a single metal or metal alloy. Such machining can be achieved using any technique known in the art, but in this embodiment, the master-side assembly 20 and the integrated F / T sensor 80 are manufactured by machining around the elastically deformable beams 90a, 90b, 90c and the central hub 82, thereby effectively cutting out the separation portion 94.

[0055] Furthermore, as best shown in Figure 4B, the master-side assembly 20 includes a portion of the locking mechanism 40. Specifically, this embodiment of the master-side assembly 20 is configured to receive a bearing race (shown in Figure 6B). As will be described in more detail later, the bearing race includes one or more circumferentially spaced corrugated notches or pockets 44 machined into its inner surface. Each notch 44 is sized and shaped to receive a corresponding spherical rolling member (e.g., a ball bearing) associated with a portion of the locking mechanism 40 integrated with the tool-side assembly 30. Note here that the bearing race may be a separate component independent of the master-side assembly 20, or it may be manufactured as a single, integrated piece together with the master-side assembly 20 and / or the F / T sensor 80, as described above.

[0056] Figures 5A and 5B are perspective and plan views, respectively, of an integrated (i.e., single-body) embodiment of the tool-side assembly 30. This embodiment of the tool-side assembly 30 and integrated F / T sensor 80 is machined from a single metal or metal alloy, as previously described. While such machining can be achieved using any technique known in the art, in this embodiment, the tool-side assembly 30 and integrated F / T sensor 80 are manufactured by machining around the elastically deformable beams 90a, 90b, 90c and the central hub 96, thereby effectively cutting out the separation 94 between the central hub 96 and the interface 98. The central chamber 100 may be formed in the same manner.

[0057] Furthermore, as best shown in Figure 5B, the tool-side assembly 30 also includes part of the locking mechanism 40. In this embodiment, the tool-side assembly 30 is configured to receive a bearing race. As described above, the surface of the bearing race is machined to include one or more circumferentially spaced corrugated notches or pockets 44, each of which is sized and shaped to receive a corresponding spherical rolling member associated with part of the locking mechanism 40 integrated with the master-side assembly 20. As described above, the bearing race may comprise a separate component independent of the tool-side assembly 30, or, as previously stated, may be manufactured as a single, integrated piece together with the tool-side assembly 30 and / or the F / T sensor 80.

[0058] Figures 6A–6C show the components of the locking mechanism 40, and Figure 7 shows how those components are connected according to embodiments of the present disclosure. More specifically, as shown in Figures 6A and 6B, the locking mechanism 40 comprises two parts: a collar 40a and a bearing race 40b. In this embodiment, the collar 40a is integrated with the tool-side assembly 30, and the bearing race 40b is integrated with the master-side assembly 20. However, those skilled in the art will readily understand that this is merely for the sake of facilitating discussion, and that the present disclosure is not limited to this particular integration of the collar and bearing races 40a, 40b. In another embodiment, for example, the collar 40a is integrated with the master-side assembly 20, and the bearing race 40b is integrated with the tool-side assembly 30.

[0059] However, regardless of their specific configuration, the collar 40a in this embodiment includes an annular ring 50. The side walls of the annular ring 50 have a plurality of holes 46 formed therein, which include a plurality of corresponding rolling members 48. In this embodiment, the collar 40a has six holes 46 and six rolling members 48, although the number of holes 46 and rolling members 48 may vary as needed or desired. The holes 46 are arranged circumferentially around the collar 40a at intervals and are positioned so that pairs of holes 46 are aligned. Thus, pairs of rolling members 48 are also aligned.

[0060] As shown in Figure 6B, the bearing race 40b defines an internal chamber 52 that is sized and shaped to receive the collar 50. Furthermore, the corrugated notches 44 are spaced circumferentially around the bearing race 40b and are aligned in pairs. Thus, when the locking lever 42 is pivoted (rotated) toward the robot tool changer 10, the rolling members 48 are forced to protrude outward from the collar 40a and contact the portions of the corrugated notches 44. In some cases, at least some of the rolling members 48 may not be precisely centered in the corresponding corrugated notches 44. That is, some of the rolling members 48 may be slightly misaligned with the corrugated notches 44.

[0061] As shown in Figure 6C, each waveform notch 44 includes a trough 44V and opposing inclined surfaces 44S extending from the trough 44V. More specifically, the trough 44V is at the center of the waveform notch 44, and the inclined surfaces 44S are on either side of the trough 44V. With one of the notches 44 as the reference point, one of the inclined surfaces 44S is called the “left” inclined surface and the other inclined surface is called the “right” inclined surface. The terms “opposed inclined surface” or “opposing inclined surface” refer to the left and right inclined surfaces 44S of a given notch 44. In the illustrated embodiment, the inclined surfaces 40S are curved. Furthermore, their radius of curvature can be varied. However, according to this disclosure, the radius of curvature must be sufficient for the rolling member 48 to contact the inclined surface 44S of the corresponding notch 44, and at the same time, it must be at least slightly offset from the center of the notch 44. As will be further explained below, the robotic tool changer 10 is designed such that when the master-side assembly 20 and the tool-side assembly 30 are joined, at least a portion of the rolling member 48 engages with and contacts the inclined surface 44S rather than the valley 44V.

[0062] Figure 7 shows an embodiment of the locking mechanism 40 in which a collar 40a is coupled to a bearing race 40b when the master-side assembly 20 and the tool-side assembly 30 are releasably coupled. As previously stated, the collar 40a is integrated with the tool-side assembly 30 and includes movable rolling members 48 within a hole 46. The bearing race 40b, formed as an annular ring, defines an internal chamber 52 configured to receive the collar 50. When coupled, the collar 40a fits into the internal chamber 52. Two of the rolling members 48 contact the right-angled surfaces 40S of opposing notches 44, and the other two rolling members 48 contact the left-angled surfaces 40S of other opposing notches 44. To provide this contact pattern, a portion of the hole 46 formed in the collar 40a and its rolling members 48 are offset from the target notches. In the context of this disclosure, the target notches are the notches 44 that the rolling members 48 are targeted to during coupling. When positioned in one of these inclined surfaces 44S of the notch 44, the rolling member 48 is slightly offset from the valley 44V of the notch 44. Because the left and right inclined surfaces 44S of the multiple notches 44 are in contact with the multiple rolling members 48, relative rotation between the master-side assembly 20 and the tool-side assembly 30 is prevented or minimized. This improves the torsional rigidity of the robotic tool changer 10.

[0063] In previous embodiments, the lock lever 42 is described as being movable between a locked position and an unlocked position. Such movement can be achieved, for example, by a user manually operating the lock lever 42. However, the present disclosure is not limited to manual operation of the lock mechanism 40. In another embodiment, for example, the lock mechanism 40 may be operated by pneumatic pressure, electric force, or biasing force. In any case, the rolling member 48 comprises a spherical member configured to move within a corresponding hole 46 between a locked position and an unlocked position in response to one or more of these forces.

[0064] Furthermore, this embodiment is not limited to relying solely on the locking mechanism 40 to ensure that the master-side assembly and the tool-side assembly are securely coupled. In some cases, a power outage may prematurely release the locking mechanism. Therefore, this embodiment also considers a secondary "safety" lock that keeps the master-side assembly 20 and the tool-side assembly 30 coupled in the event of a failure of the locking mechanism 40 (for example, in response to a power outage).

[0065] Furthermore, this embodiment is not limited to the type of locking mechanism shown in the figure. Rather, this embodiment can utilize other types of locking mechanisms that facilitate the maintenance of a robust connection. Such mechanisms include, but are not limited to, pin-type locking mechanisms, which may also be useful for use as a secondary safety lock, as mentioned above.

[0066] Furthermore, those skilled in the art should understand that the F / T sensor 80 of this disclosure is not limited to the structure described above. Rather, the F / T sensor 80 may be structurally different from the embodiment described above, for example, as shown in Figures 8A-8B, and is still suitable for integration into the master-side and / or tool-side assemblies 20, 30 according to this embodiment.

[0067] For example, Figure 8A shows a plan view of an F / T sensor 80 according to one embodiment of the present invention. As shown in Figure 8A, the central hub 96 of the tool-side assembly 30 is connected to the interface 84 of the master-side assembly 20 by three elastically deformable beams 90a, 90b, and 90c. In the illustrated embodiment, each beam 90a, 90b, and 90c is directly connected to the central hub 96 and connected to the interface 84 via a flexure 102 that assists in the deformation of the beam 90 under mechanical load. The central hub 96 is configured to connect to a first object, such as a robotic tool T, via a central chamber 100 and / or by tapped holes (not shown in this figure) on the underside of the F / T sensor 80. The interface 84 is configured to connect to a second object, such as a robotic arm R, via a plurality of mechanical fasteners extending through corresponding through-holes 88. Although not clear from this figure, the central hub 96 and the interface 84 are connected only by the flexure 102.

[0068] Pairs of transducers 92a, 92b, and 92c (e.g., strain gauges) are mounted on the upper surface (only) of each beam 90a, 90b, and 90c. In this embodiment, there are three pairs of transducers 92a, 92b, and 92c, numbered 1 through 6 for reference in later discussion. Specifically, transducers 1 and 2 in the first pair of transducers 92a are fixed to beam 90a, transducers 3 and 4 in the second pair of transducers 92b are fixed to beam 90b, and transducers 5 and 6 in the third pair of transducers 92c are fixed to beam 90c. However, there may be more or fewer pairs of transducers.

[0069] Figure 8A also shows two axes of a three-dimensional reference Cartesian coordinate system (the z-direction extending out of the figure), which are used in the following disclosure to clearly label (show) force and torque. Although not shown in Figure 8A, the F / T sensor 80 may include processing circuitry that receives electrical signals from each transducer 1-6 and processes those signals to calculate the magnitude and direction of the force and torque applied between interface 84 and the central hub 96. Such processing circuitry may comprise, for example, one or more microprocessors coupled to memory that operates to store program code and sensor data.

[0070] Figure 8B is a magnified view of a single elastically deformable beam 90a being deformed against the interface 84 of the master-side assembly 20 by a force F applied to the central hub 96 of the tool-side assembly 30. This force deforms the beam 90a slightly to the left (the figure is not scaled). A compressive force acts on the left side of the beam 90a, and a tensile force acts on the right side. Conventional F / T sensors would generate strong signals of opposite polarity, where transducers (e.g., strain gauges) mounted on these surfaces can detect the deformation and, consequently, the applied force F. However, compressive and tensile strains also occur on both sides of the upper surface of the beam 90a, increasing in magnitude with distance from the neutral axis A. The neutral axis A is a line running roughly vertically through the center of the upper surface of the beam 90a, where the compressive strain occurring on the left side of the beam 90a transitions to tensile strain on the right side. Therefore, the beam 90a is not strained at the neutral axis A.

[0071] In this embodiment, the pair of transducers 1 and 2 are fixed only to the upper surface of the beam 90a. The pair of transducers 1 and 2 are located on both sides of the neutral axis A and are spaced apart from the neutral axis A. Differential signals from the pair of transducers 1 and 2, for example signals with opposite polarity, indicate the bending (Tz, Fxy) in the upper plane of the beam 90a (i.e., torque in the z plane and force in the xy plane). Common-mode signals (i.e., signals with the same polarity) indicate the bending of the beam 90a in the z plane (i.e., caused by Fz, Txy) (i.e., force in the z plane and torque in the xy plane).

[0072] As described above, each transducer 1-6 is electrically connected to a processing circuit located either in the same location as the robot arm R or at a different location. For example, in one embodiment shown in Figure 9A, transducers 1 and 2 (without bond wires) are mounted to the beam 90 by conventional means (e.g., manually using epoxy). A printed circuit board (PCB) 104 with wire pads 106 is attached to the surface of the central hub 96. Electrical connections (e.g., via bond wires 108) are formed directly between transducers 1 and 2 and the wire pads 106 using a wire bonding machine, eliminating all manual handling of the bond wires 108. As is well known in the field of electronics, automated wire bonding is faster, more accurate, and less expensive than manual wiring.

[0073] In another embodiment, as shown in Figure 9B, transducers 1 and 2 are mounted face down on surface mount device (SMD) pads on a flexible circuit board 104 (e.g., a printed circuit board (PCB) such as a polyimide film) using solder pads. The flexible circuit board 104 is attached to the body of the F / T sensor 80, such as on the central hub 96, and has tabs that extend at least partially onto the upper surface of the beam 90a. Transducers 1 and 2, along with all other circuit components, are placed on the flexible circuit board 104 by a pick-and-place machine, reflowed, and soldered. The SMD pads are connected to other electronic devices by pre-formed circuit traces 110 (e.g., copper) on the PCB 104. This eliminates all gauge wiring at the expense of signal amplitude reduction (e.g., a decrease in signal-to-noise ratio) due to the bending of the polyimide material. In this embodiment, both manual mounting and wiring of transducers 1 and 2 are eliminated, achieving cost reduction and improvements in quality, uniformity, and production speed.

[0074] It should be noted that Figures 9A and 9B illustrate this embodiment by showing only two transducers (i.e., transducers 1 and 2 on beam 90a). However, Figures 9A and 9B and their corresponding descriptions apply similarly to all transducers 92 fixed to all beams 90.

[0075] In one embodiment, pairs of transducers 1-2, 3-4, and 5-6 on each beam 90a, 90b, and 90c are wired in a quarter-bridge topology using two fixed resistors R1 and R2, respectively, as shown in Figure 10A. As shown in Figure 10A, the six transducers 1-6 fixed to beams 90a, 90b, and 90c generate the following signals under six applied forces and torques using the reference Cartesian coordinate system of Figure 8A. In the table below, strong tensile force is denoted as "T", weak tensile force as "t", strong compressive force as "C", and weak compressive force as "c". [Table 1]

[0076] Examining Table 1 reveals that the signals generated under each load condition follow a unique pattern and can therefore be decomposed into force and torque using a known calibration matrix process.

[0077] Figures 10B-10C illustrate an embodiment in which the applied force / torque detected by the F / T sensor 80 is applied over a longer period than merely instantaneous. In particular, in this embodiment, the switching circuit first applies the excitation polarity shown in Figure 10B to obtain zero-sum signals for all axes except Fz. Next, the applied excitation voltage is switched to the configuration shown in Figure 10C, obtaining zero-sum readings for Fz and generating a non-zero-sum signal for Tz. In this way, the zero-sum equation is applied to all six force / torque axes, eliminating all common-mode signals such as temperature errors. This eliminates the need for dedicated temperature-compensated strain gauges (and the elimination of mathematical errors) and the need to manufacture non-stress mounting points for temperature-compensated gauges.

[0078] The embodiments described above show pairs of transducers fixed to a beam 90, but the disclosure is not limited thereto. In some embodiments, multiple pairs of transducers (e.g., strain gauges) may be fixed to a given beam 90. For example, Figure 11A shows an integrated F / T sensor 80 in which two pairs of transducers (e.g., strain gauges) 92 are fixed only to the top surface of each beam 90. Similar to the single transducer pair embodiment, each of the two pairs of transducers is fixed only to the top surface of the beam 90, located on either side of the neutral axis A of the beam 90 and spaced away from the neutral axis A of the beam 90. In some embodiments, a strain concentration hole may be formed between each pair of strain gauges, passing through the beam 90.

[0079] In this embodiment, multiple flexures 102 on each beam 90 prevent large compressive and tensile beam loads and significantly prevent rotation at the free end of the beam 90. As a result, the beam 90 undergoes shear deformation under all load conditions. Therefore, the electrically connected transducer, as shown in Figure 11B, is always subjected to strains of approximately equal amounts but in opposite directions (tensile / compressive) under all load conditions. The mechanical design of this embodiment exhibits some additional complexity, but can be manufactured using the same processes and tools discussed with respect to the previous embodiments, and further results in improved overall rigidity.

[0080] Furthermore, it should be understood that this embodiment is not limited to fixing the transducer to one surface of the beam 90. Rather, in some embodiments, it is beneficial to mount transducers on both the top and bottom surfaces of each beam 90. In other embodiments, the transducer or pair of transducers may be fixed to the side of a given beam 90. Moreover, this disclosure is not limited to the F / T sensor 80 including only one type of transducer 92 (for example, the same type of strain gauge fixed to all beams 90). Rather, in some embodiments, a first type of transducer may be fixed to a first beam, and a second different type of transducer may be fixed to a second different beam 90.

[0081] Furthermore, this disclosure is not limited to the size and / or shape of the deformable beam 90. According to some embodiments, the length of the deformable beam 90 is increased by forming a meandering deformable beam 90, as shown, for example, in Figures 12–14. The term “meandering” as used herein means a shape that deviates from a straight line and alternately bends or curves to one side. In other words, a directed path along the centerline of a meandering deformable beam, along the length from the attachment point to the tool-side assembly 30 to the attachment point to the master-side assembly 20 (or vice versa), deviates from a straight line by turning, curving, or angled at least once to the left (or right), and then deviates further from a straight line by turning, curving, or angled at least once to the right (or left). Of course, the meandering deformable beam may deviate left and right many times along the length from the tool-side assembly 30 to the attachment point to the master-side assembly 20. The alternating deviations do not have to be continuous. That is, the meandering deformable beam can bend multiple times in the same direction and then bend in the opposite direction. Deviations from a straight line can take the form of sharp angles or gentle curves. Note that directed paths in which the deviation from a straight line occurs only once, i.e., only to the left or to the right (such as the deformable beam 90 in the embodiment described above), are not included in the meaning of "serpentine" as used herein.

[0082] In one embodiment, a meandering deformable beam may comprise a plurality of straight beam segments connected at various angles, some of which may extend parallel to one another, thereby achieving a larger overall length of the deformable beam while fitting the meandering deformable beam into a small space. In some embodiments, segments or portions of the meandering deformable beam may be "folded back" or extend in the opposite direction to the preceding segment or portion of the beam.

[0083] Figure 12 shows a force / torque sensor 80 comprising a tool-side assembly 30 that may be connected to a tool T and a master-side assembly 20 that may be connected to a robot arm R (or vice versa). The master-side assembly 20 is arranged substantially in a ring around the tool-side assembly 30. Multiple meandering deformable beams 120a, 102b, 120c, each comprising multiple deformable beam segments connected at an angle, connect the tool-side assembly 30 to the master-side assembly 20. In the embodiment shown in Figure 12, each meandering deformable beam 120a, 120b, 120c includes a first portion that connects to the tool-side assembly 30. This first portion connects to a second portion via a "T"-shaped connection. At each end of the second portion, the meandering deformable beam "folds" in a meandering manner. Each of these meandering sections connects to the master-side assembly 20. Therefore, in this embodiment, each meandering deformable beam 120 includes two separate directed paths from an attachment point to the tool-side assembly 30 to two different attachment points to the master-side assembly 20. Each of these directed paths defines a “meandering” shape as defined and used herein.

[0084] Due to its length, the meandering deformable beam 120 allows for slight relative motion in the xy plane and the z direction (outside the plane of the paper) between the tool-side assembly 30 and the master-side assembly 20 with relatively low rigidity. In other words, the F / T sensor 80 has a greater degree of "looseness" or "play" within its operating range than, for example, a comparable-sized sensor with a linear or T-shaped deformable beam of the prior art shown in the embodiments described above. The meandering deformable beam 120 is equipped with transducers (e.g., strain gauges, not shown) on one or more sides, which convert compressive and tensile forces on the surface of the meandering deformable beam 120 into electrical signals. The strain gauges may be wired in a full Wheatstone bridge, half Wheatstone bridge, or quarter Wheatstone bridge configuration, as is known in the prior art. A data acquisition and processing system (not shown) processes the transducer output to calculate, for example, six forces and torques (Fx, Fy, Fz, Tx, Ty, Tz) acting between the tool-side assembly 30 and the master-side assembly 20, as is known in the art.

[0085] The F / T sensor 80 also includes multiple overload beams 122a, 122b, 122c extending from the tool-side assembly 30 at a first end to near (but not in contact with) the master-side assembly 20 at a second end (or vice versa). The overload beams 122 are scattered radially between the meandering, deformable beams 120. Narrow overload gaps 124a, 124b, 124c, for example, ranging from tens of thousands of an inch to thousands of an inch, isolate each overload beam 120a, 120b, 120c from the master-side assembly 20. In fact, the overload gap 124 defines the second (unconnected) end of each overload beam 122. In some embodiments, the tool-side assembly 30, the meandering, deformable beams 120, the overload beams 122, and the master-side assembly 20 are machined from a single metal to eliminate stacking tolerances in the manufacturing of the overload function.

[0086] In one embodiment, each overload gap 124 is substantially circular. If there are three overload beams 122 as shown, the circular gap 124 must extend beyond 270 degrees of the circumference, thus ensuring contact in sufficient directions to guarantee that there is no direction in which the tool-side assembly 30 can move with different gap distances. Uniform gap distances, or gap distances specifically offset in different directions to allow different working distances in Fxy / Tz using, for example, four overload beams, are determinants of the timing of contact between the overload beams 118 and the master-side assembly 20. The precise path followed by the gap 124, i.e., circular, elliptical, etc., determines the local contact stress when the overload beams 122 contact the master-side assembly 20. In one embodiment, the overload gap 124 may be formed using wire electrical discharge machining (EDM), which allows for easy machining of the gap 124 with tight tolerances. In contrast to the meandering, deformable beam 120, the overload beam 122 is straight, without bends or angles, and is shorter and thicker than the meandering, deformable beam 120. As a result, they exhibit much higher rigidity.

[0087] The overload gap 124 between the overload beam 122 and the master-side assembly 20 provides overload action, or a stopper, of force (Fxy) and torque (Tz) that move the tool-side assembly 30 in the xy plane relative to the master-side assembly 20. To provide an overload stopper against movement in the z direction (out of plane of paper), flat sections are fitted above and below the area where each overload beam 122 contacts the master-side assembly 20, i.e., above and below the overload gap 124, and shims define a small gap width. Alternatively, a precise step may be machined into the plate covering this area. Thus, all overload stoppers are fabricated with small gaps and tight tolerances using readily available techniques that do not add significant additions to the manufacturing process and do not pose a risk of damaging the F / T sensor 80. Another embodiment of the z-direction overload stopper function is that both flat sections and tapers are machined into the plates above and below the sensing element. The flat section can be positioned near the center of the transducer, and the taper continues outward from the flat section, so that both pure force overloads and torque overloads have a large contact area during overload events, reducing contact stress and further improving fatigue life / strength.

[0088] Figure 13 shows another embodiment of the F / T sensor 80 according to another embodiment of the present disclosure. In this embodiment, meandering deformable beams 120a, 120b, and 120c are connected between the tool-side assembly 30 and the master-side assembly 20. Each meandering deformable beam 120 in this embodiment is connected to the tool-side assembly 30 and the master-side assembly 20 at only one point. The meandering deformable beams 120 can be “folded” as in the embodiment of Figure 12, extending their overall length while fitting into a small space. The body of the master-side assembly 20 may occupy part of the space occupied by the other “half” of the meandering deformable beam 120 in the embodiment of Figure 12, further contributing to the overload operating stiffness of the entire F / T sensor 80. The overload beams 122a, 122b, and 122c and the overload gaps 122a, 122b, and 122c are constructed as described above.

[0089] Figure 14 shows details of the meandering, deformable beam 120a of the embodiment in Figure 13, with multiple transducers 92a, such as strain gauges, mounted on its side. The mounting of the transducers 92a may be similar for the meandering, deformable beam 120 of the embodiment in Figure 12. However, the wiring of the transducers 92a is not shown in this figure for clarity. Although the transducers 92a are shown on one surface, they may be mounted on multiple surfaces (e.g., in pairs on opposite surfaces) at any position or direction on the meandering, deformable beams 90, 120.

[0090] The meandering, deformable beam 120 shown in Figures 12-14 has segments of the beam 120 that extend parallel to each other and connect to the next continuous segment at the opposite end, forming a "fanfold" shape, however this shape is illustrative and not limiting.

[0091] Figure 15 shows yet another embodiment of the integrated F / T sensor 80 of the present disclosure, comprising meandering deformable beams 130a, 130b, and 130c. In this case, the meandering deformable beams 130a, 130b, and 130c each bend slightly to the left after the mounting point to the tool-side assembly 30, and then bend several times to the right before mounting to the master-side assembly 30. However, each beam 130 deviates from the straight line and bends to one side (left) and then to the other side (repeatedly to the right), thus satisfying the definition of a “meandering” beam as used herein.

[0092] Figure 16 shows an embodiment of the integrated F / T sensor 80 equipped with helical deformable beams 140a, 140b, and 140c. In this case, the helical deformable beams 140a, 140b, and 140c each rotate a total of 180 degrees to one side (left side) only. This exceeds the minimum cumulative deflection amount of more than 90 degrees to one side, according to the definition of helical deformable beam used herein.

[0093] Figure 17 shows an embodiment of an integrated F / T sensor 80 having multiple vertically elastically deformable beams 150. As seen in this figure, each deformable beam 150 is mounted on a tool-side assembly 30 and a master-side assembly 20, extending vertically between them. In addition, one or more transducers 92 are fixed to one or more surfaces of each beam 150. Although not explicitly shown in this figure, each transducer 92 is electrically connected to a processing circuit, for example, as shown in Figures 9A-9B, and transmits signals to the processing circuit representing the magnitude and direction of the force and torque that caused the deformation of the beam 150.

[0094] Integrating the F / T sensor 80 with the master-side or tool-side assemblies 20, 30 provides advantages and benefits that were not possible with conventional robotic tool changers. For example, a robotic tool changer configured according to this embodiment reduces the stack height. This reduction in stack height not only allows for miniaturization of the robotic tool changer 10, but also reduces the size, complexity, and cost of the robotic tool changer 10 and the master-side and tool-side assemblies 20, 30 by eliminating or replacing its components. Furthermore, by integrating the F / T sensor 80 as provided herein, the robot can quickly and easily switch between multiple tools and detect the forces acting on these tools and the robotic tool changer.

[0095] This disclosure can, of course, be implemented in ways other than those specifically described herein, without departing from the essential characteristics of this disclosure. This embodiment should be considered in all respects to be illustrative and not limiting, and all modifications that fall within the meaning and equivalent scope of the appended claims are intended to be encompassed therein.

Claims

1. It is a robotic tool changer, A master-side assembly configured to be coupled to a robot arm, A tool-side assembly having a first side configured to connect to the master-side assembly and a second side on the opposite side configured to connect to one or more tools used by the robot, Integrated into one of the master-side assembly and the tool-side assembly, A locking mechanism configured to move between a locked position and an unlocked position in order to connect and disconnect one of the master-side assembly and the tool-side assembly to the other of the master-side assembly and the tool-side assembly, respectively. It is a force / torque sensor, One or more sensing structures configured to deform elastically in response to an applied force, One or more transducers fixed to the one or more detection structures, each of the one or more transducers is configured to transmit an electrical signal representing the magnitude and direction of the applied force to a measurement circuit, A force / torque sensor equipped with, A robotic tool changer equipped with the following features.

2. The first side of the tool-side assembly is configured to be directly coupled to the master-side assembly, and the force / torque sensor is The force / torque sensor is positioned between the master assembly and the robot arm, and is mechanically coupled to the robot arm so as to be in direct contact with the tip of the robot arm, or The robot tool changer according to claim 1, wherein the force / torque sensor is positioned between the tool-side assembly and the tool used by the robot, and is mechanically coupled to the tool so as to be in direct contact with the tool used by the robot.

3. The robot tool changer according to claim 1, wherein the locking mechanism, the force / torque sensor, and one of the master-side assembly and the tool-side assembly form an integrated component.

4. The robot tool changer according to claim 1, further comprising a central hub and a mounting interface arranged in a ring around the central hub and spaced apart from the central hub.

5. Each of the one or more detection structures comprises an elastically deformable beam, and each of the one or more detection structures is Extending radially between the central hub and the mounting interface, Extending vertically, The robotic tool changer according to claim 4, wherein one or more transducers are configured to convert one or both of the tensile strain and compressive strain on the surface of a corresponding elastically deformable beam into the electrical signal transmitted to the measurement circuit.

6. The robotic tool changer according to claim 1, wherein the first detection structure comprises a first type of transducer, and the second detection structure comprises a second type of transducer different from the first type of transducer.

7. The robotic tool changer according to claim 1, wherein at least one sensing structure comprises a pair of transducers fixed to the at least one sensing structure, spaced apart from the neutral axis on the opposite side of the neutral axis of the at least one sensing structure, and the pair of transducers is fixed to the same surface of the at least one sensing structure.

8. The locking mechanism is Bearing race and A movable rolling member configured to move between the locked position and the unlocked position and to contact the bearing race in the locked position, One of the bearing race and the movable rolling member is formed in the master-side assembly, and the other of the bearing race and the movable rolling member is formed in the tool-side assembly. The aforementioned movable rolling member is Air pressure and Electric force and, Subordinate forces and The robotic tool changer according to claim 1, comprising a spherical member configured to move within a hole between the locked position and the unlocked position, depending on one of the following:

9. A master-side assembly for a robotic tool changer, wherein the master-side assembly is configured to be attached to a robotic arm and a tool-side assembly, and the master-side assembly is A locking mechanism configured to move between a locked position and an unlocked position in order to connect and disconnect the master-side assembly to and from the tool-side assembly of the robot tool changer, respectively. It is a force / torque sensor, One or more sensing structures configured to deform elastically in response to an applied force, One or more transducers fixed to the one or more detection structures, each transducer configured to transmit an electrical signal representing the magnitude and direction of the applied force to a measurement circuit, A force / torque sensor equipped with, A master-side assembly comprising the above components.

10. A tool-side assembly for a robotic tool changer, wherein the tool-side assembly is configured to connect to a master-side assembly of the robotic tool changer and to one or more tools used by the robot, and the tool-side assembly is A locking mechanism configured to move between a locked position and an unlocked position in order to connect and disconnect the tool-side assembly to and from the master-side assembly of the robot tool changer, It is a force / torque sensor, One or more sensing structures configured to deform elastically in response to an applied force, One or more transducers fixed to the one or more detection structures, each of the one or more transducers is configured to transmit an electrical signal representing the magnitude and direction of the applied force to a measurement circuit, A force / torque sensor equipped with, A tool-side assembly that includes the following features.

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