SYSTEMS AND METHODS FOR PROVIDING PROCESSING OF A VARIETY OF OBJECTS EMPLOYING MOTION PLANNING
A processing system is disclosed for providing processing of homogenous and non-homogenous objects in both structured and cluttered environments. The processing system includes a programmable motion device including an end effector, a perception system for recognizing any of the identity, location, and orientation of an object presented in a plurality of objects at an input location, a grasp acquisition system for acquiring the object using the end effector to permit the object to be moved from the plurality of objects to one of a plurality of destination bins, and a motion planning system for determining a changing portion of a trajectory path of the end effector from the object to a base location proximate to the input location, and determining an unchanging portion of a trajectory path of the end effector from the base location to a destination bin location proximate to a destination bin, wherein the unchanging portion of the trajectory path is chosen to provide a path from the base location to the destination bin location that is consistent with paths taken by other objects.
The present application claims priority to U.S. Provisional Patent Application Ser. No. 62/292,538 filed Feb. 8, 2016, the disclosure of which is hereby incorporated by reference in its entirety.
The invention generally relates to robotic and other sortation systems, and relates in particular to programmable motion control systems that are intended to be employed in changing environments requiring the motion control system to accommodate processing a variety of objects in both homogenous and heterogeneous arrangements.
Many order fulfillment operations achieve high efficiency by employing dynamic processes in which orders are picked from warehouse shelves and placed into bins that are sorted downstream. At the sorting stage individual articles are identified, and multi-article orders are consolidated into a single bin or shelf location so that they may be packed and then shipped to customers. The process of sorting these articles (or objects) has traditionally been done by hand. A human sorter picks an object from an incoming bin, finds the barcode on the object, scans the barcode with a handheld barcode scanner, determines from the scanned barcode the appropriate bin or shelf location for the object, and then places the object in the so-determined bin or shelf location where all objects for that order are placed.
Each object however, must be individually handled and processed, requiring that the programmable motion device accommodate a wide variety of objects of different sizes, shapes and weights. There remains a need therefore, for an object sortation and motion planning system for a programmable motion control system that is able to efficiently and effectively perform the automated sortation and handling of a variety of objects.
In accordance with an embodiment, the invention provides a processing system for providing processing of homogenous and non-homogenous objects in both structured and cluttered environments. The processing system includes a programmable motion device including an end effector, a perception system for recognizing any of the identity, location, and orientation of an object presented in a plurality of objects at an input location, a grasp acquisition system for acquiring the object using the end effector to permit the object to be moved from the plurality of objects to one of a plurality of processing locations, and a motion planning system for determining a trajectory path from the input location to one of the plurality of processing locations. The trajectory path includes at least one changing portion that is determined specific to the object'"'"'s location or orientation at the input location, and at least one unchanging portion that is generally used in determining trajectory paths for a plurality of objects.
In accordance with another embodiment, the invention provides a processing system for providing sortation of homogenous and non-homogenous objects in both structured and cluttered environments. The processing system includes a programmable motion device including an end effector, a perception system for recognizing any of the identity, location, and orientation of an object presented in a plurality of objects at an input location, a grasp acquisition system for acquiring the object using the end effector to permit the object to be moved from the plurality of objects to one of a plurality of processing locations, and a motion planning system for determining a trajectory path from the input location to one of the plurality of processing locations. The trajectory path includes at least one changing portion that is determined specific to the object'"'"'s location or orientation at the input location, and at least one unchanging portion that is predetermined and is not specific to the object, the object'"'"'s location or the object'"'"'s orientation at the input area.
In accordance with a further embodiment, the invention provides a method of providing processing of homogenous and non-homogenous objects in both structured and cluttered environments. The method includes the steps of acquiring an object from an input location using an end effector of a programmable motion device to permit the object to be moved from the plurality of objects to one of a plurality of processing locations, and determining a trajectory path of the end effector from the object to one of the plurality of processing locations. The trajectory path includes at least one changing portion that is determined specific to the object'"'"'s location or orientation at the input location, and at least one unchanging portion that is predetermined and is not specific to the object, the object'"'"'s location or the object'"'"'s orientation at the input area.
The following description may be further understood with reference to the accompanying drawings in which:
The drawings are shown for illustrative purposes only.
Systems of various embodiments of the invention, automate part of the sorting process in conjunction with a programmable motion control system (such as for example, a linear indexing pick and place system, a drone system, or any of a wide variety of robotic systems, including articulated arm robot systems, concentric tube robot systems, and parallel arm (Delta-type arm) robot systems). In particular, systems of various embodiments of the invention involve the steps of identifying and moving selected objects. A programmable motion control system picks an object from an input area, passes the object near a scanner, and then, having obtained identification information for the object (such as a barcode, QR codes SKU codes, other identification codes, information read from a label on the object, or size, weight and/or shape information), places the object in the appropriate location in accordance with a manifest.
In accordance with certain embodiments, the invention provides a novel motion planning system for the purposes of efficiently and effectively moving individual objects to a set of destination locations, e.g., sorting locations. In applications such as order fulfillment, objects (articles or goods etc.) are collected into heterogeneous sets and need to be sorted. Individual objects need to be identified and then routed to object-specific locations. In accordance with certain embodiments, the system reliably automates the movement of such objects by employing automated programmable motion (e.g., robotic) systems and motion planning.
Important components of an automated processing (e.g., robotic sortation) system in accordance with an embodiment of the present invention are disclosed with reference to
The system provides in an embodiment, an automated article identification system that includes a robotic pick and place system that is able to pick articles up, move them in space, and place them. The system may also include: the set of objects themselves to be identified, the manner in which inbound objects are organized (commonly in a heterogeneous pile in a bin or in a line on a conveyor), the manner in which outbound objects are organized (commonly in an array of outbound bins, or shelf cubbies), the manner in which objects are labeled with barcodes or radio-frequency identification tags, a fixed primary scanner operating above the incoming stream of objects, a scanning station where one or more scanners and illuminators are activated when the object is held at the station, and a central computing and control system determines the appropriate location for placing the object (which is dependent on the object'"'"'s decoded barcode).
As noted, the robotic pick and place system may include a robotic arm equipped with sensors and computing, that when combined is assumed herein to exhibit the following capabilities: (a) it is able to pick objects up from a specified class of objects, and separate them from a stream of heterogeneous objects, whether they are jumbled in a bin, or are singulated on a motorized or gravity conveyor system; (b) it is able to move the object to arbitrary places within its workspace; (c) it is able to place objects in an outgoing bin or shelf location in its workspace; and, (d) it is able to generate a map of objects that it is able to pick, represented as a candidate set of grasp points in the workcell, and as a list of polytopes enclosing the object in space.
The allowable objects are determined by the capabilities of the robotic pick and place system. Their size, weight and geometry are assumed to be such that the robotic pick and place system is able to pick, move and place them. These may be any kind of ordered goods, packages, parcels, or other articles that benefit from automated sorting. Each object is associated with a universal product code (UPC) or other unique object identifier, which identifies the item or provides information (such as an address) that itself directs object processing.
As discussed above, the system of an embodiment includes a perception system 26 that is mounted above a bin of objects to be sorted, looking down into the bin. A combination of 2D and 3D (depth) data is acquired. The system uses this imagery and a variety of algorithms to generate a set of candidate grasp locations for the objects in the bin.
In accordance with various embodiments, the invention provides a programmable motion system that may learn object grasp locations from experience and human guidance. Most robotic systems, for example, designed to localize objects and pick them up, rely on a suite of sensors to give the system information about the location, size, pose, and even identity of an object. Such systems designed to work in the same environments as human workers will face an enormous variety of objects, poses, etc. The 2D/3D imagery in conjunction with the human-selected grasp points can be used as input to machine learning algorithms, to help the robotic system learn how to deal with such cases in the future, thereby reducing the need for operator assistance over time. A combination of 2D and 3D (depth) data is acquired, the system uses this imagery and a variety of algorithms to generate a set of candidate grasp points for the objects in the bin.
In addition to geometric information the system may learn the location of fiducial markers such as barcodes on the object, which can be used as indicator for a surface patch that is flat and impermeable, hence suitable for a suction cup. One such example is shipping boxes and bags, which tend to have the shipping label at the object'"'"'s center of mass and provide an impermeable surface, as opposed to the raw bag material which might be slightly porous and hence not present a good grasp. In accordance with further examples, the fiducial marker itself may not be the target, but may provide a reference for finding a target grasp location. Once a product is identified and its orientation is known for example, a certain distance (e.g., x, y) from a fiducial marker may be used as an optimal grasp location.
The robotic system may employ motion planning using a trajectory database that is dynamically updated over time, and is indexed by customer metrics. The problem domains contain a mix of changing and unchanging components in the environment. For example, the objects that are presented to the system are often presented in random configurations, but the target locations into which the objects are to be placed are often fixed and do not change over the entire operation.
One use of the trajectory database is to exploit the unchanging parts of the environment by pre-computing and saving into a database trajectories that efficiently and robustly move the system through these spaces. Another use of the trajectory database is to constantly improve the performance of the system over the lifetime of its operation. The database communicates with a planning server that is continuously planning trajectories from the various starts to the various goals, to have a large and varied set of trajectories for achieving any particular task. In various embodiments, a trajectory path may include any number of changing and unchanging portions that, when combined, provide an optimal trajectory path in an efficient amount of time.
The robotic system may include a defined home or base location 84 to which each object may initially be brought upon acquisition from the bin (e.g., 56). In certain embodiments, the system may include a plurality of base locations, as well as a plurality of predetermined path portions associated with the plurality of base locations. The trajectories taken by the articulated arm of the robot system from the input bin to the base location 84 are constantly changing based in part, on the location of each object in the input bin, the orientation of the object in the input bin, and the shape, weight and other physical properties of the object to be acquired.
Once the articulated arm has acquired an object and is positioned at the base location, the paths to each of the destination bins 86-102 are not changing. In particular, each destination bin 86-102 is associated with a unique destination bin location 106, 108, 110, 112, 114, 116, 118, 220, 222 and the trajectories from the base location 84 to each of the destination bin locations individually is not changing. A trajectory, for example, may be a specification for the motion of a programmable motion device over time. In accordance with various embodiments, such trajectories may be generated by experience, by a person training the system, and/or by automated algorithms. For a trajectory that is not changing, the shortest distance is a direct path to the target destination bin, but the articulated arm is comprised of articulated sections, joints, motors etc. that provide specific ranges of motion, speeds, accelerations and decelerations. Because of this, the robotic system may take any of a variety of trajectories between, for example, base location 84 and destination bin location 106.
The risk factor may be determined in a number of ways including whether the trajectory includes a high (as pre-defined) acceleration or deceleration (linear or angular) at any point during the trajectory. The risk factor may also include any likelihood that the articulated arm may encounter (crash into) anything in the robotic environment. Further, the risk factor may also be defined based on learned knowledge information from experience of the same type of robotic arms in other robotic systems moving the same object from a base location to the same destination location.
As shown in the table at 130 in
The choice of fast time vs. low risk factor may be determined in a variety of ways, for example, by choosing the fastest time having a risk factor below an upper risk factor limit (e.g., 12 or 14), or by choosing a lowest risk factor having a maximum time below an upper limit (e.g., 1.0 or 1.2). Again, if the risk factor is too high, valuable time may be lost by failure of the robotic system to maintain acquisition of the object. An advantage of the varied set is robustness to small changes in the environment and to different-sized objects the system might be handling: instead of re-planning in these situations, the system iterates through the database until it finds a trajectory that is collision-free, safe and robust for the new situation. The system may therefore generalize across a variety of environments without having to re-plan the motions.
Further, in accordance with certain embodiments, the system of
Overall trajectories therefore, may include any number of changing and unchanging sections. For example. networks of unchanging trajectory portions may be employed as commonly used paths (roads), while changing portions may be directed to being objects to a close by unchanging portion (close road) to facilitate moving the object without requiring the entire route to be planned. For example, the programmable motion device (e.g., a robot) may be tasked with orienting the grasped object in front of an automatic labeler before moving towards the destination. The trajectory to sort the object therefore, would be made up of the following trajectory portions. First, a grasp pose to a home position (motion planned). Then, from home position to an auto-labeler home (pulled from a trajectory database). Then, from the auto-labeler home to a labelling pose (motion planned). Then, from the labelling pose to an auto-labeler home (either motion planned or just reverse the previous motion plan step). Then, from the auto-labeler home to the intended destination (pulled from the trajectory database). A wide variety of changing and unchanging (planned and pulled from a database) portions may be employed in overall trajectories. In accordance with further embodiments, the object may be grasped from a specific pose (planned), and when the object reaches a destination bin (from the trajectory database), the last step may be to again place the object in the desired pose (planned) within the destination bin.
In accordance with further embodiments, each programmable movement system 80 may be provided with a plurality of home positions, and motion paths may be identified from each of the home positions in various embodiments. In accordance with further embodiments, multiple processing stations may be provided. In certain embodiments, therefore, a system may use the motion planning to plan a shorter overall distance by requiring that the system plan a path from the object grasp pose to a closest home position of several (e.g., a grid of) home positions.
With reference to
Another advantage of the varied set is the ability to address several customer metrics without having to re-plan motions. The database is sorted and indexed by customer metrics like time, robustness, safety, distance to obstacles etc. and given a new customer metric, all the database needs to do is to reevaluate the metric on the existing trajectories, thereby resorting the list of trajectories, and automatically producing the best trajectory that satisfies the new customer metric without having to re-plan motions.
Another advantage is that even if they are invalid due to changes in the environment or customer metrics, these stored trajectories can serve as seeds for trajectory optimization algorithms, thereby speeding up the generation of new trajectories in new situations.
A further advantage is that the database offers a mechanism for different systems to share information remotely or over a network such as the Internet.
Motion planning systems of the invention may also be tailored to achieve further objectives such as reducing shear force between a gripper and an object, or moving an object that is open at the top. For example,
With reference to
In certain embodiments, the end effector may be a tubular or conical shaped bellows. The magnetic field sensor may communicate (e.g., wirelessly) with a controller, which may also communicate with a flow monitor to determine whether a high flow grasp of an object is sufficient for continued grasp and transport as discussed further below. In certain embodiment, for example, the system may return the object if the air flow is insufficient to carry the load, or may increase the air flow to safely maintain the load.
In accordance with further embodiments, systems of the invention may provide motion planning that accommodates specific needs or requirements, such that an opened container or box be moved without spilling the contents. For example,
Those skilled in the art will appreciate that numerous modifications and variations may be made to the above disclosed embodiments without departing from the spirit and scope of the present invention.