Controlled compliant grasping and manipulation system for robots

Abstract

A compliant end effector includes a robot mounting bracket and a component support member. The component support member includes a side surface and a top surface. A component clamping system includes a first clamp member operable to move toward the side surface of the component support member and a second clamp member operable to move toward the top surface of the component support member. A controller is operably connected to the clamping system. The controller is configured to engage the first and second clamp members when the component grasping and manipulation system is in a set position and release the first clamp member and the second clamp member when the component grasping and manipulation system is moving to the set position, allowing a portion of a component held by the component clamping system to move in one or more degrees of freedom.

Description

TECHNICAL FIELD

[0001] The subject disclosure relates to the technology of manufacturing robots, and more specifically, to a controlled compliant gripping and manipulation system for robots. BACKGROUND

[0002] Robots are commonly used in manufacturing processes. Robots can be used to weld, install components, operate fasteners, perform inspections, etc. In some environments, a robot can include two or more gripping devices that hold and / or manipulate an object. In other environments, two or more robots can hold an object. A robot with two or more gripping devices does not require a complex coordination scheme. That is, the robot can control each gripping device to hold the object. When two or more robots hold an object, coordination is required to reduce the application of unnecessary stress.

[0003] Coordinating the actions of two or more robots requires sensors, feedback circuits, and complex programming. Misalignment between two robots holding a single object can cause strain that can result in breakage, weld breakage, or other damage. Furthermore, misalignment in any position can result in a faulty application of a component, create an unwanted opening, or a bead or be in misalignment with a pre-planned position or in an unwanted position. Accordingly, the industry would welcome a system that can easily and simply coordinate the operations between two different robots manipulating the same object without applying undesirable stress. SUMMARY

[0004] According to a non-limiting example, a compliant end effector for a component gripping and manipulation system includes a robot mounting bracket mountable to a robot manipulator arm, and a component support member connected to the robot mounting arm. The component support member includes a side surface and a top surface. A component clamping system includes a first clamp member operable to move toward the side surface of the component support member and a second clamp member operable to move toward the top surface of the component support member. A controller is operably connected to the clamping system. The controller is configured to engage the first and second clamp members when the component gripping and manipulation system is in a set position, and release the first clamp member and the second clamp member when the component gripping and manipulation system is moving to the set position, allowing a portion of a component held by the component clamping system to move in one or more degrees of freedom.

[0005] In addition to one or more features described herein, the component support member includes a first component support member having a first side surface and a first top surface, and a second component support member having a second side surface and a second top surface, wherein the first clamp member is operable to move toward the first side surface.

[0006] In addition to one or more of the features described herein, the component support member includes a first support element fixedly mounted relative to the robot mounting bracket and a second support member engageable with the supported component.

[0007] In addition to one or more of the features described herein, the second support element is displaceable relative to the first support element.

[0008] In addition to one or more of the features described herein, the second support element includes a side surface and a top surface.

[0009] In addition to one or more of the features described herein, the first clamp member urges the supported component against the side surface of the second support element.

[0010] In addition to one or more of the features described herein, the second clamp member urges the supported component against the top surface of the second support element.

[0011] In addition to one or more of the features described herein, the second clamp member includes a rotatable arm connected to a rotary actuator.

[0012] In addition to one or more of the features described herein, the first clamp member includes a piston coupled to a linear actuator.

[0013] In addition to one or more of the features described herein, the component grounding system is supported by the component support member, the component grounding system providing an electrical ground for the supported component.

[0014] According to non-limiting examples, a component gripping and manipulation system is also disclosed, including a first robot having a first component end effector fixedly connected to a first end of a component and a second robot having a second component end effector compliantly connected to a second end of the component. The second component end effector includes a robot mounting bracket connected to the second robot and a component support member connected to the robot mounting arm. The component support member includes a side surface and a top surface. A component clamping system includes a first clamp member operable to move toward the side surface of the component support member and a second clamp member operable to move toward the top surface of the component support member. A controller is operably connected to the clamping system. The controller is configured to engage the first and second clamp members when the component gripping and manipulation system is in a set position and to release the first clamp member and the second clamp member when the component gripping and manipulation system is moving to the set position, allowing a portion of the component held by the component clamping system to move in one or more degrees of freedom.

[0015] In addition to one or more of the features described herein, the component support member includes a first component support member having a first side surface and a first top surface, and a second component support member having a second side surface and a second top surface, wherein the first clamp member is operable to move toward the first side surface.

[0016] In addition to one or more of the features described herein, the component support member includes a first support element fixedly mounted relative to the robot mounting bracket and a second support member engageable with the supported component.

[0017] In addition to one or more of the features described herein, the second support element is displaceable relative to the first support element.

[0018] In addition to one or more of the features described herein, the second support element includes a side surface and a top surface.

[0019] In addition to one or more of the features described herein, the first clamp member urges the supported component against the side surface of the second support element.

[0020] In addition to one or more of the features described herein, the second clamp member urges the supported component against the top surface of the second support element.

[0021] In addition to one or more of the features described herein, the second clamp member includes a rotatable arm coupled to a rotary actuator.

[0022] In addition to one or more of the features described herein, the first clamp member includes a piston coupled to a linear actuator.

[0023] In addition to one or more of the features described herein, the component grounding system is supported by the component support member, the component grounding system providing an electrical ground for the supported component.

[0024] The above features and advantages and other features and advantages of the present disclosure are readily apparent from the following detailed description when taken in connection with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0025] Other features, aspects, and details are described in only an example, with reference to the drawings, in which:

[0026] Figure 1 depicts a perspective view of a controlled component grasping system according to non-limiting examples;

[0027] Figure 2 depicts a plan view of a compliant end effector of a controlled component grasping system according to non-limiting examples of Figure 1

[0028] Figure 3 ​Depicting based on non-restrictive examples Figure 2 Exploded view of the compliant end effector of the controlled component grasping system;

[0029] Figure 4 It is based on the cut along line 4-4 of the non-restrictive example. Figure 2 The end view of the compliant end effector;

[0030] Figure 5 It is based on the cut along line 5-5 of the non-restrictive example. Figure 2 Top view of the partial cross-section of the compliant end effector; and

[0031] Figure 6 A perspective view of a compliant end effector of a controlled part grasping system, based on a non-limiting example, is depicted. Detailed Implementation

[0032] The following description is exemplary in nature only and is not intended to limit this disclosure, its application, or its uses. It should be understood that in all the drawings, corresponding reference numerals denote the same or corresponding parts and features. As used herein, the term module refers to processing circuitry, which may include application-specific integrated circuits (ASICs), electronic circuitry, processors (shared, dedicated, or grouped), and memory executing one or more software or firmware programs, combinational logic circuitry, and / or other suitable components that provide the described functions.

[0033] According to a non-limiting example, a component grasping and manipulating system in Figure 1 The part gripping and manipulating system 10 is generally designated as 10. The part gripping and manipulating system 10 includes a first robot manipulator 16 spaced apart from the second robot manipulator 18. The first robot manipulator 16 includes a first manipulator arm 22 on which a first end effector 24 is attached. The second robot manipulator 18 includes a second manipulator arm 28 having a second end effector 30. Each robot manipulator arm 16 and 18, and its associated end effector 24, 30, is an independent device whose control can be orchestrated to manipulate individual parts.

[0034] As described herein, according to a non-limiting example, the first end effector 24 is a fixed end effector, i.e., when connected, the end effector holds the component so that any degrees of freedom (e.g., up / down; left / right; and / or in / out) are always prohibited. In contrast, the second end effector 30 is a compliant end effector, i.e., the end effector loosely or in a manner that allows the component to move in one or more degrees of freedom when being manipulated. With a compliant end effector, the component is still supported, but some movement is allowed so that stress is not introduced into the component during manipulation. More specifically, the freedom of movement at one end prevents stress from being introduced into the component during manipulation due to any mismatch or lack of synchronization between the first robotic manipulator 16 and the second robotic manipulator 18.

[0035] In a non-limiting example, the first end effector 24 is fixedly connected to a first end 32 of the component 34, and the second end effector 30 is compliantly connected to a second, opposite end 35 of the component 34. In a non-limiting example, the component 34 is shown in the form of a frame rail 36 that is undergoing a manufacturing process. In a non-limiting example, a first control system 39 having a first control module 38 is connected to the first robotic manipulator 16, and a second control system 42 having a second control module 44 is connected to the second robotic manipulator 18. The first and second control systems 39 and 42 direct the first and second robotic manipulators 16 and 18 to manipulate the frame rail 36 into position for a manufacturing step (e.g., part connection, welding, etc.) based on instructions received by or stored in the first and second control modules 38 and 44.

[0036] Referring now to Figures 2-5 and with continued reference to Figure 1 , the second end effector 30 is described according to a non-limiting example. The second end effector 30 includes a robot mounting bracket 53 that serves as an interface with the second manipulator arm 28. In a non-limiting example, a component support and clamping system 60 is supported by the robot mounting bracket 53. The component support and clamping system 60 includes a support bracket 62 to which a component support 66 is connected.

[0037] In Figure 3 the non-limiting example shown, the component support 66 includes a first component support member 70 and a second component support member 72. The first component support member 70 is fixed relative to the second component support member 72. The first and second component support members 70 and 72 are sized and spaced from one another so as to be inserted into the second end 35 of the frame rail 36, as shown in Figure 4 and 5 The first and second support members 70 and 72 are selectively floatable within the second end 35 of the frame rail 36. In Figures 3-5In the non-limiting example shown, the first component support member 70 includes a first support element 78 and a second support element 80. Similarly, the second component support member 72 includes a first support element 82 and a second support element 84.

[0038] In a non-limiting example, the second support element 80 of the first component support member 70 can, through the interaction of the first support member 86, move along axis "A" ( Figure 5 The second support element 84 of the second component support member 72 transitions relative to the first support element 78 through the interaction of the second support member 88. In this way, when manipulated, the frame guide rail 36 can translate along the first degree of freedom defined by axis "A". In a non-limiting example, the second support element 80 of the first component support member 70 includes a first side surface 90 and a first top surface 92. The first side surface 90 includes a first angled surface portion 94.

[0039] In a non-limiting example, the second support element 84 of the second component support member 72 includes a second side surface 96 and a second top surface 98. The second side surface 96 includes a second angled surface portion 100. The first and second angled surface portions 94, 100 limit the amount of surface area of ​​each second support element 80, 84 in order to reduce frictional forces that may inhibit movement of the frame guide rail 36 relative to the first component support member 70 and the second component support member 72.

[0040] exist Figure 4 In the non-limiting example shown, the first component support member 70 may include a first upper support member 101 and a first lower support member 102. The first upper support member 101 may be defined by, for example, first and second support elements 78 and 80. The first lower support element 102 may be defined by third and fourth lower support elements (not separately indicated). Similarly, the second component support member 72 may include a second upper support member 104 and a second lower support member 105. The second upper support member 104 may be defined by first and second support elements 82 and 84. The second lower support member 105 may be defined by third and fourth lower support elements (not separately indicated). Although shown as being formed by upper and lower support elements, each component support member 70 and 72 may be formed by a single member.

[0041] In a non-limiting example, the component clamping system 116 is supported by a component support and a clamping system 60. The component clamping system 116 includes a first clamping member 120 and a second clamping member 122. The first clamping member 120 includes, as shown in the example... Figure 4 The first clamp 124 and the second clamp 126 shown are Figure 3). The first clamp 124 is connected to a drive shaft 127 that is rotated by a rotary actuator 130. The second clamp 126 includes a corresponding structure. The first and second clamps 124 and 126 are supported by a structure 128. When the rotary actuator is activated, the clamp 124 moves into contact with the second side surface 96 of the second support element 84 and pushes or forces the frame rail 36 toward the second side surface 96 of the second support element 84. When activated, the second end 35 of the frame rail 36 is locked or fixedly supported by the second end effector 30.

[0042] In Figure 4 In the non-limiting example shown, the second clamp member 122 takes the form of a component grounding system 129, including a first clamp component 136 and a second clamp component 138. The first clamp component 136 takes the form of a first piston 140 connected to a first linear actuator 142, and the second clamp component 138 takes the form of a second piston 143 connected to a second linear actuator 144. When activated, the first and second linear actuators 142 and 144 drive or push the first and second clamp components 136 and 138 against the first top surface 92 of the first component support member 70 and the second top surface 98 of the second component support member 72, establishing an electrical ground to support welding operations and further locking the second end 35 of the frame rail 36 to the second end effector 30.

[0043] In operation, when the frame rail 36 is moved between selected static positions, the second control module 44 releases the first clamp member 120 and the second clamp member 122. When released, the second end 35 of the frame rail 36 can float or move with one or more degrees of translational and / or rotational freedom relative to the first component support member 70 and the second component support member 72. In one non-limiting example, the second or compliant end effector 30 can include sensors that measure linear and / or rotational displacement of one or more degrees of freedom of the end of the frame rail 36. The sensors can provide feedback to, for example, the second control system 42 indicating the amount of movement of the second end 35 of the frame rail 36 when being manipulated, in order to detect and / or stop any excessive or undue travel conditions. In a non-limiting example, the second end 35 of the frame rail 36 can move with at least three degrees of freedom relative to the first component support member 70 and the second component support member 72, namely forward / backward, up / down, and side-to-side movement. Accordingly, any mismatch in movement, no matter how small or large, is not input to the frame rail 36, thereby creating stresses that can cause internal weaknesses.

[0044] While the first and second robot manipulators 16 and 18 position the frame guide rail 36 in a selected orientation for a manufacturing step, the first control module 38 clamps the first end 32 of the frame guide rail 36, and the second control module 44 activates the first and second clamping members 120 and 122 to clamp the second end 35 of the frame guide rail 36. At this time, another robot(s) (not shown) may apply welds, install fasteners, form openings, etc. The other robot(s) may use machine vision to locate specific areas on the frame guide rail 36, or, in a non-limiting example, may receive feedback from sensors indicating specific positions on the frame guide rail 36, including any offsets attributable to the second end effector 30. Once the manufacturing step is complete, the second control module 44 releases the first and second clamping members 120 and 122, allowing the second end 35 of the frame guide rail 36 to float with one or more degrees of freedom, while the frame guide rail 36 is manipulated to a position for the next manufacturing step.

[0045] On this point, it should be understood that various modifications can be made. For example, such as Figure 6 As shown, the compliant end effector 200 can be designed to grip and manipulate larger components, such as vehicle frame 210. The compliant end effector 200 includes a component support 220, which includes a first component support 230 and a second component support 234. The second component support 234 may include a first support element 236 and a second support element 238. When manipulated between selected positions, the component support 220 loosely grips the vehicle frame 210. The compliant end effector 200 also includes a component clamping system 260, which includes a first clamping member 280 and a second clamping member 300.

[0046] The first clamping member 280 includes a first clamp 302 and a second clamp 304, shown in the form of rollers (not separately labeled). The second clamping member 300 includes a third clamp 308 and a fourth clamp 310, shown in the form of rollers (also not separately labeled). The first and second clamping members 280 and 300 secure the vehicle frame 210 during the manufacturing process, but release the clamping force during manipulation of the vehicle frame 210 in a manner similar to that discussed herein, in order to eliminate stress that may be caused by movement mismatch between the robots. In a non-limiting example, the rollers further facilitate movement of the vehicle frame 210 during manipulation to mitigate or prevent stress caused by positional mismatch between the end effectors.

[0047] When it is necessary to use two robots to manipulate a part; as described herein, providing a fixed end effector for one robot and a compliant end effector for the second robot results in reduced stress on the part and the robots during operation. Parts that exceed the weight limit of a single robot, parts that have a length that are better supported at multiple points; and / or parts that are difficult for a single robot to manipulate, assigning two or more robots for a particular process can improve manufacturing goals and hold the integrity of the part.

[0048] While the foregoing disclosure has been described in reference to exemplary embodiments, it will be understood by those skilled in the art that various changes can be made and equivalents can be substituted for elements thereof without departing from the scope thereof. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the disclosure without departing from the central scope thereof. Therefore, it is intended that the disclosure not be limited to the particular embodiment disclosed as the only means for carrying out the disclosure.

Claims

1. A compliant end effector for a component gripping and manipulation system, comprising: a robot mounting bracket mountable to a robotic manipulation arm; a component support member connected to the robotic manipulation arm, the component support member comprising a side surface and a top surface; a component clamping system comprising a first clamp member operable to move toward the side surface of the component support member and a second clamp member operable to move toward the top surface of the component support member; and a controller operably connected to the clamping system, the controller configured to engage the first clamp member and the second clamp member when the component gripping and manipulation system is at a set position and to release the first clamp member and the second clamp member when the component gripping and manipulation system is moving to a set position, allowing a portion of a component held by the component clamping system to move in one or more degrees of freedom.

2. The compliant end effector of claim 1, wherein, the component support member comprises a first component support member having a first side surface and a first top surface and a second component support member having a second side surface and a second top surface, wherein the first clamp member is operable to move toward the first side surface.

3. The compliant end effector of claim 1, wherein, the component support member comprises a first support element fixedly mounted relative to the robot mounting bracket and a second support element engageable with a supported component.

4. The compliant end effector of claim 3, wherein, the second support element is displaceable relative to the first support element.

5. The compliant end effector of claim 4, wherein, the second support element comprises a side surface and a top surface.

6. The compliant end effector of claim 5, wherein, the first clamp member urges the supported component against the side surface of the second support element.

7. The compliant end effector of claim 5, wherein, the second clamp member urges the supported component against the top surface of the second support element.

8. The compliant end effector of claim 1, wherein, the second clamp member comprises a rotatable arm connected to a rotary actuator.

9. The compliant end effector of claim 1, wherein, the first clamp member comprises a piston coupled to a linear actuator.

10. The compliant end effector of claim 1, further comprising a component grounding system supported by the component support member, the component grounding system providing an electrical ground for a supported component.

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