Patent Description:
The disclosure herein generally relate to gripping mechanisms, and, more particularly, to an adaptive gripper device.

Gripping systems enable gripping of objects. Current gripping system have fingers driven by actuators, in which the gripping system pick objects which are in gripping range. The problem in the current gripping systems is that they do not have much intelligence to estimate the object picking positions and holding positions, and have restrictions where the fingers hold the objects which are having height. For example holding a book with two fingers which is placed on the floor is much difficult as the book border does not have much space to grip at the edges. In order to hold such objects, the dimensions of the object should be within the range of gripping components. Other types of gripping systems are vacuum cups based which pick and place objects where they can handle multidimensional objects. However, these types of vacuum cups based gripping systems heavily depend on surface of objects. For example, such vacuum cups based gripping systems would require the surface of the objects to be flat or smooth enough to use vacuum cups, and cannot handle the rough surfaced or multi vertex shaped objects.

<CIT> discloses a method for automatically gripping, via a polyarticulated system secured to a viewing system, an object located in an area capable of receiving at least one object, said polyarticulated system comprising at least one gripping member capable of grabbing an object by a specific area of said object. According to the invention, the method comprises at least the steps of: capturing an image of the receiving area via the viewing system; processing the information resulting from the 3D image and identifying all the specific areas that the objects to be grabbed can include, and which are compatible with the one or more gripping members; locating the position and direction of the one or more compatible specific areas identified; selecting one of the located compatible specific areas and automatically defining, for the corresponding gripping member, a path for taking the corresponding object by the selected compatible specific area; grabbing the corresponding object according to the defined path.

<CIT> discloses a robot hand used for a multi-joint robot. This robot hand is provided with a pair of fingers, driven to open / close by the hand body to grasp and hold a first work, and an adsorption pad provided on each of the fingers for sucking and holding a work.

<CIT> discloses a robot hand having a plurality of suction ports and capable of switching the suction ports with a simpler construction. A robot hand comprises: a gripper having a pair of openable fingers; a first suction pad disposed at the leading end of the fingers; a second suction pad disposed on the side face of the gripper; a pump for sucking the first suction pad and the second suction pad; and a valve connected to the pump for switching the first suction pad and the second suction pad in association with the joint part of the fingers.

<CIT> discloses an integrated gripper comprising a kernel processor, a servo gripper finger member, a pneumatic member and an interface member; the servo gripper finger member comprises at least two fingers, a servo actuator, and a motor, the fingers being driven by the motor to grip and/or move an object; the pneumatic member, comprising a cup, a vacuum generator and a pneumatic actuator, is configured to suck and/or blow off an object; the kernel processor is configured to control the servo actuator of the servo gripper finger member and the pneumatic actuator of the pneumatic member; and the interface member comprises a power supply interface, a bus interface and an air input interface, the power supply interface, the bus interface and the air input interface being connected to a power supply, a bus and an air input respectively. A robot comprising the integrated gripper is also disclosed. Compared with the existing prior art, the proposed solution makes the gripper more functional with compact solution and makes the robot system more flexible.

<CIT> discloses a robot hand having gripping fingers capable of gripping a gripping point suitable for gripping an object. A robot hand is constituted such that a stem is provided with three fingers of a gripping finger, a gripping finger and an adsorptive finger longer than the gripping fingers. The stem is connected to the arm portion of a not-shown robot. The adsorptive finger is provided with a first articulation, a second articulation, a third articulation, a fourth articulation and a fifth articulation, as recited in the order closer to the stem.

<CIT> discloses a gripping device for gripping a component with a carrier body, and with movable fingers arranged in space on the carrier body via base joints, wherein at least one finger has an end member and an intermediate member connected to the end member via a finger joint, wherein the end member and at least one intermediate member at least one activatable gripping means is provided.

<CIT> discloses a highly extensible robot hand capable of taking out a variety of parts and changing postures thereof, and a robot device. A robot hand comprises a pair of fingers and attached to a tip of a hand body, gripping parts for gripping parts attached to the tips of the fingers so as to be turnable, wires for turning the gripping parts, air cylinders for pulling the wires, springs for returning the gripping parts to predetermined positions, and adsorbers connected to a vacuum device through flexible tubes and attached to the tips of the gripping parts. The robot hand is controlled by a robot control device.

<CIT> discloses an end effector system adapted to be used for robotic tooling applications which allows the end effector to be used to acquire parts by vacuum pick-up or grasping. A vacuum type end effector is provided at the end of each of two robotic tooling fingers. Each vacuum type end effector includes a flexible bellows member on the end thereof such that it can be used for vacuum acquisition. Extending down from each finger to reside adjacent a respective bellows is a pinch member. Through robotic control of the movement of the fingers, finger gripping can be accomplished to grip an object between the two bellows using the pinch members for lateral support. As the part is captured between the two bellows, each bellows is compressed against its respective pinch member. In such manner, the bellows are at least partially collapsed such that a vacuum sensor located in the vacuum supply line to the bellows registers that a vacuum is present and, thus, a part has been acquired. That same vacuum sensor allows the robot to know when a part has been acquired by the bellows in the typical vacuum-type pick-up arrangement.

Embodiments of the present disclosure present technological improvements as solutions to one or more of the above-mentioned technical problems recognized by the inventors in conventional systems. For example, in one aspect, a gripper device is provided. The gripper device comprises a base comprising a first end and a second end; a plurality of fingers, wherein a fixed finger comprising a top end and a bottom end, wherein the bottom end of the fixed finger is coupled to the first end of the base, a sliding finger comprising a top end and a bottom end, wherein the bottom end of the sliding finger is positioned at the second end of the base and opposite to the fixed finger; a plurality of suction cups, wherein a first suction cup is attached to the fixed finger such that the first suction cup is in close proximity of the top end of the fixed finger, wherein a second suction cup is attached to the fixed finger such that the second suction cup is in close proximity of the bottom end of the fixed finger, and wherein a third suction cup is attached between the top end and the bottom end of the sliding finger; an electronic device that is configured to capture information of an object to be grasped, wherein the information is indicative of holding position of the object; and a hardware processor is configured to determine an optimal holding orientation and an optimal movement of at least one of (i) the plurality of fingers, or (ii) the plurality of suction cups based on the captured information obtained from the electronic device, and identify the at least one of (i) the plurality of fingers, or (ii) the plurality of suction cups as one or more optimal grasping components based on the information on the object, the determined optimal holding orientation and the determined optimal movement.

In one embodiment, the gripper device may further comprise one or more proximity sensors configured to detect position of the object from the plurality of fingers. In one embodiment the sliding finger is configured to move from a first position to a second position based on position and dimension of the object. In one embodiment, the gripper device may further comprise an actuator that is configured to enable the one or more optimal grasping components to grasp the object based on the information on the object, the determined optimal holding orientation and the determined optimal movement.

In one embodiment, the plurality of suction cups are identified as the one or more optimal grasping components to grasp the object based on (i) a suction provided by the actuator and (ii) a determination of centre of gravity on the object, wherein the centre of gravity on the object is determined by the hardware processor based on the captured information. In one embodiment, the centre of gravity on the object is determined by the hardware processor based on the determined optimal holding orientation and the determined optimal movement.

In another aspect, a method is provided according to independent claim <NUM>. In particular, the method comprises capturing, using an electronic device, information of an object, wherein the information of the object is indicative of holding position; determining, using the information, by a hardware processor, an optimal holding orientation and an optimal movement of at least one of (i) a plurality of fingers, or (ii) a plurality of suction cups of a gripper device based on the captured information obtained from the electronic device; identifying the at least one of (i) the plurality of fingers, and (ii) the plurality of suction cups as one or more grasping components based on the information, the optimal holding orientation and the optimal movement; and enabling, using an actuator, the one or more identified grasping components to grasp the object based on the information, the optimal holding orientation and the optimal movement. In one embodiment, the plurality of suction cups are identified as the one or more optimal grasping components to grasp the object based on (i) a suction provided by the actuator and (ii) a determination of centre of gravity on the object by the hardware processor. In one embodiment, a sliding finger of the plurality of fingers is configured to move from a first position to a second position based on position and dimension of the object.

In the figures, a reference number identifies a component(s)/part(s).

<FIG> illustrates a perspective view of an adaptive gripper device <NUM> according to an embodiment of the present disclosure. The adaptive gripper device <NUM> (also hereinafter referred as "gripper device <NUM>" or device <NUM>). The gripper device <NUM> comprises a base <NUM>, a plurality of fingers 104A-B, a plurality of suction cups 106A-C, a plurality of push-in fittings 108A-C, and an actuator <NUM>. The base <NUM> comprises a first end 102A and a second end 102B. A first finger 104A from the plurality of fingers 104A-B comprises a top end 112A and a bottom end 112B. In one embodiment, the first finger 112A is a fixed finger, wherein the bottom end 112B of the fixed finger 112A is coupled (or fixed) to the first end 102A of the base <NUM>. In one embodiment, a second finger 104B of the plurality of fingers 104A-B comprises a first end 114A and a second end 114B. In one embodiment, the second finger 104B is a sliding finger, wherein the bottom end 114B of the sliding finger 104B is positioned at the second end 102B of the base <NUM> such that the sliding finger 104B faces towards, and is opposite to, the fixed finger 104A. The sliding finger 104B is configured to move (and/or slide) from the second end 102B of the base <NUM> to the first end 102A of the base <NUM> and back to a desired position respectively. Although <FIG> depicts only two fingers, it is to be understood to a person having ordinary skill in the art that there could be more than two fingers comprised in the gripper device <NUM>. In one embodiment, the sliding finger 104B is configured to move from a first position to a second position based on position and dimension of an object to be grasped. A first suction cup 106A of the plurality of suction cups 106A-C is attached to the fixed finger 104A such that the first suction cup 106A is in close proximity of the top end 112A of the fixed finger 104A. Similarly, a second suction cup 106B from the plurality of suction cups 106A-C is attached to the fixed finger 104A such that the second suction cup 106B is in close proximity of the bottom end 112B of the fixed finger 104A. Similarly, a third suction cup 106C from the plurality of suction cups 106A-C is attached between the first end 114A and the second end 114B of the sliding finger 104B. Although <FIG> depicts only three suction cups, it is to be understood to a person having ordinary skill in the art that there could be more than three suction cups comprised in the gripper device <NUM>.

Each of the fingers 104A-B comprise a hole (not shown in <FIG>) that is configured to accommodate a push-in fitting on a first side, and a suction cup on another side of the hole. For example, as depicted in <FIG>, the fixed finger 104A comprises a hole (not shown in <FIG>) that is adapted to accommodate a first push-in fitting 108A such that a first end 116A of the first push-in fitting 108A is connected to a first end 118A of the first suction cup 106A through the hole via a fixing means (also referred hereinafter fixing component). Similarly, the fixed finger 104A comprises another hole (not shown in <FIG>) that is adapted to accommodate a second push-in fitting 108B such that a first end 120A of the second push-in fitting 108B is connected to a first end 122A of the second suction cup 106B through the another hole via a fixing means. Similarly, the sliding finger 104B comprises a hole (not shown in <FIG>) that is adapted to accommodate a third push-in fitting 108C such that a first end 124A of the first push-in fitting 108C is connected to a first end 126A of the third suction cup 106A through a corresponding hole via a fixing means. The other ends (the second end 116B, the second end 120B, and the second 124B) of the push-in fittings 108A-C are connected to corresponding pipes (e.g., suction pipes) that provide suction to corresponding suction cups 106A-C using one or more suction providers. In one embodiment, the gripper device <NUM> implements one or more solenoids to control the suction cups 106A-C for gripping and releasing of objects.

The actuator <NUM> may comprise any of a lead screw mechanism, a pneumatic mechanism, a hydraulic mechanism, and the like. In an example embodiment, the actuator <NUM> comprises a lead screw mechanism is depicted in <FIG>. The second end 114B of the sliding finger 104B is coupled to (or attached to) the lead screw mechanism such that when the actuator is activated, the screw of the lead screw mechanism drives the sliding finger to either sides of the base <NUM>. When the actuator <NUM> comprises a mechanism other than lead screw mechanism, the actuator <NUM> enables the sliding finger 104B to slide or move on either sides of the base <NUM>.

The gripper device <NUM> further comprises an electronic device (not shown in <FIG>), a memory (not shown in <FIG>), a hardware processor (not shown in <FIG>), and an input/output (I/O) interface (not shown in <FIG>). The electronic device, the memory, the hardware processor may be either integrated within the gripper device <NUM>, or connected to the gripper device <NUM> through an external interfaces. It may be understood that one or more memory units, one or more hardware processors, and/or one or more communication interfaces may be comprised in the gripper device <NUM>. The electronic device may be an image capturing device, a laser device, a depth camera, and the like. The electronic device, the memory, the hardware processor, and the input/output (I/O) interface may be coupled by a system bus or a similar mechanism.

The memory, may store instructions, any number of pieces of information, and data (e.g., depth information, image associated with an object to be grasped, or object information), captured by the electronic device, for example to implement the functions of the device <NUM>. The memory may include for example, volatile memory and/or non-volatile memory. Examples of volatile memory may include, but are not limited to volatile random access memory (RAM). The non-volatile memory may additionally or alternatively comprise an electrically erasable programmable read only memory (EEPROM), flash memory, hard drive, or the like. Some examples of the volatile memory includes, but are not limited to, random access memory, dynamic random access memory, static random access memory, and the like. Some example of the non-volatile memory includes, but are not limited to, hard disks, magnetic tapes, optical disks, programmable read only memory, erasable programmable read only memory, electrically erasable programmable read only memory, flash memory, and the like. The memory <NUM> may be configured to store information, data, instructions or the like for enabling the device <NUM> to carry out various functions in accordance with various example embodiments.

Additionally or alternatively, the memory may be configured to store instructions which when executed by the hardware processor causes the gripper device <NUM> to behave in a manner as described in various embodiments. The memory stores the functional modules and information, for example, information (e.g., proximity information of object from (i) the fingers 104A-B, and/or the suction cups 106A-C) received from the one or more proximity sensors (not shown in <FIG>). The proximity sensors may be attached to the gripper device <NUM> and are configured to determine the proximity of the object (e.g., position and/or distance of the object) from (i) the fingers 104A-B, and/or the suction cups 106A-C. In one embodiment, the one or more proximity sensors are attached to (or fixed to) each of the inward layers of the fingers 104A-B. Similarly, the one or more proximity sensors may be attached to (or fixed to) the surfaces of each of suction cups 106A-C. In one embodiment, the suction cups 106A-C may be positioned on the fingers 104A-B such that proximity sensors on the surfaces of the suction cups 106A-C determine the proximity of the object (e.g., position and/or distance of the object) from the suction cups 106A-C.

The hardware processor may be implemented as one or more microprocessors, microcontrollers, digital signal processors, central processing units, state machines, logic circuitries, and/or any devices that manipulate signals based on operational instructions. Further, the hardware processor may comprise a multi-core architecture. Among other capabilities, the hardware processor is configured to fetch and execute machine-readable instructions or modules stored in the memory. The hardware processor may include circuitry implementing, among others, audio and logic functions associated with the communication. For example, the hardware processor may include, but are not limited to, one or more digital signal processors (DSPs), one or more microprocessor, one or more special-purpose machine chips, one or more field-programmable gate arrays (FPGAs), one or more application-specific integrated circuits (ASICs), one or more machine(s), various analog to digital converters, digital to analog converters, and/or other support circuits.

The hardware processor thus may also include the functionality to encode messages and/or data or information. The hardware processor may include, among others a clock, an arithmetic logic unit (ALU) and logic gates configured to support operation of the hardware processor. Further, the hardware processor may include functionality to execute one or more software programs, which may be stored in the memory or otherwise accessible to the hardware processor.

<FIG>, with reference to <FIG>, illustrates a front view of the adaptive gripper device <NUM> according to an embodiment of the present disclosure. More particularly, <FIG> depicts the fingers 104A-B in an open mode and <FIG> depicts the fingers 104A-B in a closed mode according to an embodiment of the present disclosure. <FIG>, with reference to <FIG>, illustrates a rear view of the adaptive gripper device <NUM> according to an embodiment of the present disclosure. <FIG>, with reference to <FIG>, illustrate side views of the adaptive gripper device <NUM> according to an embodiment of the present disclosure. More particularly, <FIG> illustrates a left side view of the adaptive gripper device <NUM> and <FIG> illustrates a right side view of the adaptive gripper device <NUM> according to an embodiment of the present disclosure. <FIG>, with reference to <FIG>, illustrates a top view of the adaptive gripper device <NUM> according to an embodiment of the present disclosure. More particularly, <FIG> illustrates a top view of the adaptive gripper device <NUM> depicting the actuator <NUM> comprising a lead screw mechanism <NUM> according to an example embodiment of the present disclosure. The lead screw mechanism <NUM> comprises a screw <NUM> that enables the sliding finger 104B to slide from one end to another end of the base <NUM> (e.g., enable the sliding finger 104B to move towards fixed finger 104A and/or away from the fixed finger 104A in the opposite direction). <FIG>, with reference to <FIG>, illustrates a bottom view of the adaptive gripper device <NUM> according to an embodiment of the present disclosure.

<FIG>, with reference to <FIG>, is a flow diagram illustrating a processor implemented method using the adaptive gripper device <NUM> of <FIG> according to an embodiment of the present disclosure. The steps of the method of the present disclosure will now be explained with reference to the components of the gripper device <NUM> as depicted in <FIG>. The hardware processor is configured by the instructions stored in the memory. The hardware processor when configured by the instructions enables the gripper device <NUM> to function in a particular manner as described hereinafter. At step <NUM>, the hardware processor enables the electronic device (integrated into or attached to the gripper device <NUM>) to capture information of an object (or objects) to be grasped. In one embodiment, the captured information is indicative of holding position of the object. In another embodiment, the captured information may comprise depth information of the object, or any such information that is indicative of size, shape, and dimension of the object. At step <NUM>, the hardware processor determines an optimal holding orientation and an optimal movement of at least one of (i) the plurality of fingers 104A-B, and/or (ii) the plurality of suction cups 106A-C based on the captured information obtained from the electronic device. At step <NUM>, the hardware processor identifies at least one of (i) the plurality of fingers 104A-B, and (ii) the plurality of suction cups 106A-C as one or more optimal grasping components based on the captured information on the object, the determined optimal holding orientation and the determined optimal movement. At step <NUM>, the hardware processor with the help of the actuator <NUM> enables the one or more identified grasping components to grasp the object based on the information, the optimal holding orientation and the optimal movement. In one embodiment, the one or more identified grasping components perform pick and place function for objects in a particular orientation and/or particular movement/direction based on the determined optimal holding orientation and the determined optimal movement. This ensures that the gripper device <NUM> grips the objects firmly and ensures that the object does not fall and is rather grasped (or held) tightly. In one embodiment, the plurality of suction cups 106A-C are identified as the one or more optimal grasping components to grasp the object based on (i) the suction provided by suction provider or by the actuator <NUM> and (ii) a determination of centre of gravity on the object. The centre of gravity on the object may be determined by the hardware processor based on the captured information.

The embodiments of the present disclosure provide an adaptive gripper device <NUM> that addresses problems/ limitations in conventional gripping systems. Unlike conventional gripping systems, the proposed gripper device <NUM> is adapted to grasp different objects with different combinations of picking and placing them by implementing proximity sensors, electronic device(s) that identifies shape(s), orientation(s) of the object and intelligently identifies at least one of (i) the plurality of fingers 104A-B, and (ii) the plurality of suction cups 106A-C as one or more optimal grasping components based on the captured information on the object, the determined optimal holding orientation and the determined optimal movement.

Further, the embodiments of the present disclosure provide dynamic movement of the suction cups 106A-C which help in positioning the suction cups with different orientations based on the object (or properties of the object). The position of the fingers 104A-B, and the position of the suction cups 106A-C enable different types of triangular formations which helps to hold the objects and avoid the problem of centre of gravity on the object. Unlike conventional gripping systems which lack in determining sensitivity of object(s), the embodiments of the present disclosure enable the gripper device <NUM> to identify the object shape and position of holding and maintain the gripping force based on the sensitivity of the object. When the suction cups 106A-C are identified as the one or more grasping components, each of the suction cups 106A-C are continually provided with suction. This ensures that even when a particular suction cup fails to grip (or hold or grasp) a certain part of the object during a particular orientation and/or movement in a direction, that particular suction cup may at any moment attempt to grip that certain part of the object when the orientation and/or movement (or direction) of the gripper device <NUM> changes (based on intelligent decision making abilities of the hardware processor). For example, the gripper device <NUM> (or the hardware processor) may transmit a signal to attempt gripping of that certain part of the object when an appropriate orientation and/or movement (or angle) is observed. In other words, while an object is being grasped, a second suction cup 106B fails to grip a part (e.g., curve part) of the object) during a first orientation and/or first movement (or first direction). When the gripper device <NUM> continues to move and detects a second orientation and/or a second movement (or second direction), the gripper device <NUM> may transmit a signal to the suction cup 106B requesting to attempt to grip (or requesting to grasp or grip) that curve part of the object (where the suction cup previously failed to grip the object). This signal transmission may be either based on the captured information or object information being captured in real-time (using the electronic device) during real-time orientation, and/or real-time movement of the gripper device <NUM>. This enables the gripper device <NUM> to ensure that objects are properly gripped (or tightly gripped) and do not fall out during orientation(s) and/or movement(s) in one or more direction(s) as can be observed in conventional (or traditional) gripping systems.

It is to be understood that the scope of the protection is extended to such a program and in addition to a machine-readable means having a message therein; such machine-readable storage means contain program-code means for implementation of one or more steps of the method, when the program runs on a machine or any suitable programmable device (e.g., the gripper device <NUM>). The device may also include means which could be e.g. hardware means like e.g. an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a combination of hardware and software means, e.g. an ASIC and an FPGA, or at least one microprocessor and at least one memory with software modules located therein.

The embodiments that are implemented in software include but are not limited to, firmware, resident software, microcode, etc. The functions performed by various modules described herein may be implemented in other modules or combinations of other modules. For the purposes of this description, a machine-usable or machine readable medium can be any apparatus that can comprise, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.

Furthermore, one or more machine-readable storage media may be utilized in implementing embodiments consistent with the present disclosure. A machine-readable storage medium refers to any type of physical memory on which information or data readable by a processor may be stored. Thus, a machine-readable storage medium may store instructions for execution by one or more processors, including instructions for causing the processor(s) to perform steps or stages consistent with the embodiments described herein. The term machine-readable medium" should be understood to include tangible items and exclude carrier waves and transient signals, i.e., be non-transitory. Examples include random access memory (RAM), read-only memory (ROM), volatile memory, nonvolatile memory, hard drives, CD ROMs, BLU-RAYs, DVDs, flash drives, disks, and any other known physical storage media.

Claim 1:
A gripper device (<NUM>), comprising:
a base (<NUM>) comprising a first end (102A) and a second end (102B);
a plurality of fingers (104A-B), including
a fixed finger (104A) comprising a top end (112A) and a bottom end (112B), wherein said bottom end (112B) of said fixed finger (104A) is coupled to said first end (102A) of said base (<NUM>), a sliding finger (104B) comprising a top end (114A) and a bottom end (114B), wherein said bottom end (114B) of said sliding finger (104B) is positioned at said second end (102B) of said base (<NUM>) and opposite to said fixed finger (104A); a plurality of suction cups (106A-C), wherein a first suction cup (106A) is attached to said fixed finger (104A) such that said first suction cup (106A) is in close proximity of said top end (112A) of said fixed finger (104A), wherein a second suction cup (106B) is attached to said fixed finger (104A) such that said second suction cup (106B) is in close proximity of said bottom end (112B) of said fixed finger (104A), and wherein a third suction cup (106C) is attached between said top end (114A) and said bottom end (114B) of said sliding finger(104B);
an electronic device that is configured to capture information of an object to be grasped, wherein said information is indicative of holding position of said object; and
a hardware processor that is configured to
determine an optimal holding orientation and an optimal movement of at least one of (i) said plurality of fingers (104A-B), or (ii) said plurality of suction cups (106A-C) based on the captured information obtained from the electronic device, and
identify said at least one of (i) said plurality of fingers (104A-B), or (ii) said plurality of suction cups (106A-C) as one or more optimal grasping components based on said information on said object, said determined optimal holding orientation and said determined optimal movement.