Patent Application
20200130935
The invention generally relates to object processing systems, and relates in particular to object processing systems such as automated storage and retrieval systems, distribution center systems, and sortation systems that are used for processing a variety of objects.
Automated storage and retrieval systems (AS/RS), for example, generally include computer controlled systems for automatically storing (placing) and retrieving items from defined storage locations. Traditional AS/RS typically employ totes (or bins), which are the smallest unit of load for the system. In these systems, the totes are brought to people who pick individual items out of the totes. When a person has picked the required number of items out of the tote, the tote is then re-inducted back into the AS/RS.
In these traditional systems, the totes are brought to a person, and the person may either remove an item from the tote or add an item to the tote. The tote is then returned to the storage location. Such systems, for example, may be used in libraries and warehouse storage facilities. The AS/RS involves no processing of the items in the tote, as a person processes the objects when the tote is brought to the person. This separation of jobs allows any automated transport system to do what it is good at—moving totes—and the person to do what the person is better at—picking items out of cluttered totes. It also means the person may stand in one place while the transport system brings the person totes, which increases the rate at which the person can pick goods.
There are limits however, on such conventional object processing systems in terms of the time and resources required to move totes toward and then away from each person, as well as how quickly a person can process totes in this fashion in applications where each person may be required to process a large number of totes. There remains a need therefore, for an object processing system that stores and retrieves objects more efficiently and cost effectively, yet also assists in the processing of a wide variety of objects.
In accordance with an embodiment the invention provides a system for object processing. The system includes a supply location having one or more objects to be processed, a plurality of object processing stations for processing objects, an object classification system, and a routing system. The object classification system includes an identification system for identifying an object at the supply location, a first data repository having a first set of object information, and a second data repository having a second set of object information, the second set of object information including processing parameters. The first set of object information is supplied with the object and the second set of object information is determined by the system, and the object classification system assigns the object to a class based on the first set of information and the second set of information. The routing system for routing an object from the supply location to a selected object processing station capable of processing objects in the assigned class, wherein the selected object processing station processes the object according to the determined processing parameters.
In accordance with another embodiment the invention provides a method of processing objects. The method includes the steps of: presenting an object to a routing station, evaluating provided object information and determined object information associated with the object, wherein the determined object information includes processing parameters, classifying the object based on provided and determined object information, selecting a picking station to process the object based on object classification, routing the object from the routing station to the selected picking station, processing the object at the picking station according to said processing parameters, observing the object being processed at the processing station, scoring the object handling performance based on observed criteria, and updating the processing parameters based on object handling performance score.
In accordance with a further embodiment the invention provides a method of processing objects. The method includes the steps of: providing, at a supply location, one or more objects to be processed, providing an object classification system, wherein the object classification system includes: an identification system for identifying an object at the supply location, a first data repository having a first set of object information, and a second data repository having a second set of object information, said second set of object information including feature information regarding a plurality of objects, The method also includes the steps of providing the first set of object information with the object, providing the second set of object information via a feedback learning system, wherein the second set of object information includes feature information regarding object features, assigning the object to a class based on the first set of information and the second set of information, and updating the second set of object information following engagement with the object.
In accordance with yet a further embodiment the invention provides a method of processing objects. The method includes the steps of: providing, at a supply location, one or more objects to be processed, capturing identification data for the object, querying a first data repository having a first set of object information, determining that the identification data for the object is not included within the first set of object information, identifying object feature data regarding the object, querying a second data repository having a second set of object information, said second set of object information including feature information regarding a plurality of objects, identifying associated object information within the second set of object information, said associated object information including learned feature data that closely matches the object feature data, said learned feature data being associated with a related object, and engaging with a programmable motion device, the object using grasp and acquisition data regarding the related object.
The following description may be further understood with reference to the accompanying drawings in which:
The drawings are shown for illustrative purposes only.
An unstructured and dynamic physical environment such as an order fulfillment center presents unique challenges to operators. A nearly endless variety of goods needs to be identified, picked up, and routed. Human workers set a high bar for recognizing attributes and similarities between objects they encounter. In order for robots to be as fast as or faster than a human, artificial intelligence (AI), and machine learning in particular, are required to improve system performance in the face of operational complexity.
In accordance with an embodiment, the invention provides an automated material handling system that is tasked, in part, with routing objects carried in bins to stations where objects are transferred from one bin to another with one or more programmable motion devices (such as articulated arms) at automated stations, and may further include manual stations. The bins may be containers, totes, or boxes etc. An overall objective of the system may be to sort and ship goods, to perform order fulfillment, to replenish store stock, or to provide any general-purpose system requiring the transfer of individual objects from one bin to another.
The objects may be packages, boxes, flats or polybags etc. in a shipping center, or consumer products in an e-commerce order fulfillment center, or products and warehouse packs in a retail distribution center (DC). The bins might be bins from an automatic storage and retrieval system (AS/RS), vendor cases, store replenishment boxes, or any other containing mechanism designed to hold items separate from one another. The conveyance of bins could take many forms, including belt or roller conveyors, chutes, mobile robots, or human workers. The picking stations, where items are transferred, might be automated systems including programmable motion devices, such as articulated arm robotic systems.
The automated material handling system employs a policy that executes an algorithm or process to determine how to route bins to picking stations. One such algorithm might be to balance the load so that all picking stations are utilized and none are idle. In some cases, however, uniquely configured picking stations may be employed throughout the system that have different capabilities for processing different object types. For example, pick station A may be worse at picking item X, than is pick station B, and therefore it is better to send item X to pick station B. In this case, another algorithm can be employed to route objects through the system, taking into account the strengths and weaknesses of various pick stations. Furthermore, it may be that robotic pick station A has pick modes 1 and 2, and that mode 2 is better at picking item X. In accordance with various embodiments, the invention provides a system incorporating a set of processes for learning how to optimize both a routing to pick stations and parameters pertinent to pick station operation, so as to increase the performance of the overall operation. The optimization chooses routing and handling parameters that enhance the expected overall performance of picking according to various kinds of criteria, including throughput and accuracy, conditioned on the contents of the bins.
Learning, in the sense of improving over time, is a key aspect of systems of embodiments of the invention. The system provides the performance of picking as a function of item, pick station and handling parameters. Further, objects that have not yet been picked will periodically be encountered. It is likely, however, that new objects that are similar to previously picked items, and will have similar performance characteristics. For example, object X may be a kind of shampoo in a 20 ounce bottle, and object Y may be conditioner in a 20 ounce bottle. If distributed by the same company, then the shape of the bottles may be the same. Accordingly, handling of the bottles would likely be the same or very similar. Systems of embodiments of the invention include processes that use observations of past performance on similar items to predict future performance, and learn what characteristics of the items available to the system are reliable predictors of future performance.
Every pick is a new data point. There are many variables throughout the picking process that can be altered to provide new data points. For example, the system can change the speed of robot arm motions, the location on an object where it is picked, the gripper type used, the gripping force applied, etc. The principal outcome examined is whether the object was successfully moved from its source location to a desired destination.
Specifically,
The top phase of the cycle begins with phase 21 that provides general data collection within a warehouse or order fulfillment center. The system uses previously successful arrangements to process objects and collects data about these arrangements to improve the model. At this stage, safe and gradual alterations to the arrangements are made that compound over millions of picks. In some embodiments, the altered arrangements make up a very small percentage, e.g. less than one percent, of total picks, to provide reliability in the system.
Phase 22 also takes place in the warehouse, and uses a multitude of sensors to determine, broadly, whether each pick has been successful or not. The sensors also provide detailed information about various sensed attributes throughout processing. This continued monitoring allows the system to adjust certain attributes to improve outcomes, or to generally correct mistakes. This automated sensing relieves a worker from having to manually identify and label a utilized arrangement as a success or failure. The system can operate more reliably, missing fewer instances of failure than a human worker in most cases, as well as providing more and nearly instantaneous data reporting about a success or failure.
Phase 23 represents the act of getting the collected data out of the warehouse. Collected data can include sensed data, as well as order data or other data to provide a complete context to each pick that can be broken down and analyzed. This data transfer out of the warehouse can be compressed and sub-sampled to reduce network impact.
Phase 24 occurs offline and offsite, using the logged data, including context and outcome pairs, to learn policies to control the various operational variables used. For example, in some embodiments, policies for grasp location, and robot actions and behaviors such as arm speeds and trajectories can be developed, or previously used policies can be reinforced, based on discovered patterns in the data. This can lead to associations between SKUs that indicate potentially successful policies for a newer object for which the system has less or no information.
Phase 25 tests and validates new policies before they are introduced to the warehouse. The new policies can be tested using real systems and typically encountered objects, or can be tested using simulations of real world processing. By isolating the testing and validation, operational risk is isolated from the warehouse. Mistakes made offline outside of the warehouse do not impact actual order fulfillment, for example. During this exploratory phase, millions of situations are practiced or simulated both to improve policy performance and to ensure appropriate behavior of learned behaviors.
Phase 26 orchestrates the deployment of new policies to warehouses to act as the primary operational policies during processing. The deployment occurs as a gradual roll-out of the learned policies to the sites. In some embodiments, the roll-out is provided only to certain areas within the warehouse, or to certain warehouses if multiple warehouses are to be affected by the new policies in order to provide another layer of reliability in the new policies. Once the roll-out is complete (whether partially or fully), the cycle returns once again to the top phase 10, continuing the cycle.
In accordance with certain embodiments, systems of the invention provide certain information that is determined to be absolutely correct, or ground truth (GT) information, regarding a variety of parameters through such feedback learning. For example, weight sensors may be used to determine or confirm a multi-object pick occurrence as follows. The weight sensors may be used to determine that more than one object has been grasped, for example, if an item is identified yet the experienced weight is much greater than that of the identified object. If such a grasp is maintained (even for a short period) the system will note any or all of: the air flow at the end effector, the change in air flow at the end effector, the vacuum level during grasp at the end effector, the change in vacuum during grasp at the end effector, the change in any of weight, linear acceleration, angular acceleration, or rotation. Such noted changes (or events of not having changed) will then be correlated with performance (a successful grasp and acquisition, or a not successful grasp and acquisition), and may be further detailed with regard to whether such gasps repeated over time are generally successful and/or whether the movement (acquisition) repeated over time is generally successful. The use of such sensing may permit the system to determine ground truths (GT) with respect to a specific object, stock keeping unit (SKU), or other set of known information. For example, if an object with a known SKU is grasped, and the system then detects that any of change in vacuum during grasp at the end effector, the change in any of weight, linear acceleration, angular acceleration, or rotation is recorded that is associated with a multi-pick, the system will know (GT) that the acquired object is a multi-pick and needs to be processed not as the identified SKU or other known information may dictate, but rather as a multi-pick that needs to be either re-processed or processed by human personnel. The sooner the system knows that a pick violated GT, the sooner the system may re-process or post-process the multi-pick. If a weight of an object is not known, but the object is identified by a SKU, the system may record the weight load when the object is engaged by an end effector, and then note the weight load on the end effector again after the object is dropped. Further, weight scales (such as weight sensing carriages) may be used. Within a short time, the known weight (ground truth weight) of the object will be recorded with certainty for that SKU.
In accordance with further embodiments, systems of the invention provide certain information that is determined to be absolutely correct, or ground truth (GT) information, regarding a variety of parameters through such feedback learning. For example, weight sensors may be used to determine or confirm a multi-object pick occurrence as follows. The weight sensors may be used to determine that more than one object has been grasped, for example, if an item is identified yet the experienced weight is much greater than that of the identified object. If such a grasp is maintained (even for a short period) the system will note any or all of: the air flow at the end effector, the change in air flow at the end effector, the vacuum level during grasp at the end effector, the change in vacuum during grasp at the end effector, the change in any of weight, linear acceleration, angular acceleration, or rotation. Such noted changes (or events of not having changed) will then be correlated with performance (a successful grasp and acquisition, or a not successful grasp and acquisition), and may be further detailed with regard to whether such gasps repeated over time are generally successful and/or whether the movement (acquisition) repeated over time is generally successful. The use of such sensing may permit the system to determine ground truths (GT) with respect to a specific object, SKU or other set of known information. For example, if an object with a known SKU is grasped, and the system then detects that any of change in vacuum during grasp at the end effector, the change in any of weight, linear acceleration, angular acceleration, or rotation is recorded that is associated with a multi-pick, the system will know (GT) that the acquired object is a multi-pick and needs to be processed not as the identified SKU or other known information may dictate, but rather as a multi-pick that needs to be either re-processed or processed by human personnel. The sooner the system knows that a pick violated GT, the sooner the system may re-process or post-process the multi-pick. If a weight of an object is not known, but the object is identified by a SKU, the system may record the weight load when the object is engaged by an end effector, and then note the weight load on the end effector again after the object is dropped. Further, weight scales (such as weight sensing carriages) may be used. Within a short time, the known weight (ground truth weight) of the object will be recorded with certainty for that SKU.
In accordance with further embodiments, the system provides a learning process that (a) extrapolates the performance of newly seen objects, and (b) is continually updating the data with which it learns to extrapolate so as to continually improve performance. The potential pick parameters are diverse. Several controllable pick parameters may govern the process, such as, which picking stations can pick a given item, which effectors (vacuum cup size or gripper type) are effective for that item, what rules might be used to choose locations on an item to grasp etc. Because these process parameters can change on a per-SKU basis, and will determine the efficacy and speed of a picking station and further may be determined on a per-SKU basis, it is necessary to estimate these parameters correctly. In particular, the correct values of process parameters depend on the nature of the item, its weight and size, its packaging, its material properties such as whether it is deformable or clear, whether vacuum grippers are effective at holding it, where good grasp locations are on the object, and whether it is easily damaged.
In many operating conditions however, this can be challenging, as new SKUs may be present, which means that there is no known set of parameters available. While these parameters will be learned from repeated interactions with the object, this can slow down handling time considerably. To speed up the time it takes to learn the appropriate parameters, using previously recorded data based on similar SKUs can be useful. In accordance with certain embodiments, systems of the invention may employ 3-D modelling of objects, and train on generated data, for example, by seeking to associate 3-D models with data regarding known objects.
In accordance with further embodiments, system of the invention may direct correlating information not on SKUs but on packaging. In such systems, a generalization or description of a packaging (e.g., shape, size, weight, length, width, height, circumference or center or mass) may be provided as an association event, and the system may act in accordance with the closest association event parameters. For example, some package features such as known rectangular surface areas on common boxes, known shapes of indicia on common boxes, known contours of common objects, and known features of certain objects such as clam-shell cases, may be learned and be the subject of learned knowledge. Again, a performance of such actions is also recorded regarding either whether the performance was successful (successful grasp and acquisition) or not successful (not a successful grasp or acquisition).
In accordance with various embodiments, the invention provides processes for an automated material handling system that routes bins to picking stations, and which provides the following. The system may predict object-specific parameters for new objects based on previously seen objects. For new objects similar to previously handled objects, the processes predict what are expected to be good routing and handling parameters. In this instance an object is readily recognized as being quite similar to objects with which the system has extensive experience. From the bar code or SKU number or product category or description text or from appearance or other features, the system might recognize the object and index information in the database, which might include process parameters, or will at least include information from which process parameters can be determined with high confidence.
Further, the system may explore the parameter space for completely unknown objects. For new objects that are not sufficiently similar to any previously handled objects, the system may propose multiple candidate routing and handling parameters with the aim of finding good routing and handling parameters. When an unfamiliar object is first introduced, process parameters must be determined.
The system may also update predictive models of object-specific handling performance from observed item handling performance. Processes refine the routing and handling parameters on an object basis, as experience with that object is gained. The predictive model is refined as experience is gained.
The system may further update predictive models of object-to-object similarity from observed object handling performance. The parameters affecting the schemes and processes for classifying and/or clustering objects are refined as experience with all available items is increased. Further, the system may recognize and correct for persistent discrepancies in actual versus predicted performance. Some objects, when replenished by the manufacturer, have different weights, packaging or other characteristics that impact the object's handling performance. Old routing and handling parameters that yielded good performance before may be inappropriate for the changed object. When the actual performance repeatedly exceeds the range of the predicted performance, the system favors exploration of the parameter space.
In accordance with various embodiments, a set of object information includes feature information regarding object features, and the feature information may be developed associated with any of object SKU, text description, product category, object manufacturer, object mass, object material, object shape, packaging details, object images, and object color. For example, the system may collect such feature information regarding an object as the object is grasped and acquired. The system may engage cameras and scanners to collect any text description, product category, object manufacturer, object mass, object material, object shape, packaging details, object images, and object color information, and associate the information with the SKU. Such collected information is associatively recorded (e.g., tabulated, networked, commonly connected or grouped etc.) and is therefore associated with each other and with the SKU. The system may further engage in machine learning in the processing of pixels of images from the cameras by learning at a pixel level how best to break apart images of objects, for example, in hierarchical representations.
In accordance with further embodiments, the feature information may be developed associated with any of sensed information, object weight, object material, object shape, object opacity, object size, object volume, effector to be used, grip location, object movement limitations, object fragility, and object processing limitations. Similarly, the system may collect such feature information regarding an object as the object is grasped and acquired. The system may engage sensors to collect any sensed information, object weight, object material, object shape, object opacity, object size, object volume, effector to be used, grip location, object movement limitations, object fragility, and object processing limitations, and associate the information with the SKU. Such collected information is associatively recorded (e.g., tabulated, networked, commonly connected or grouped etc.) and is therefore associated with each other and with the SKU. In any of these embodiments, the number of associations of any of the above factors may be used to identify a grasp location and action to be taken to provide a positive grasp and acquisition, and such further actions may be recorded for further machine learning.
In such embodiments of the invention, the machine learning systems may engage reward feedback such that when an item (identified as discussed above) is grasped and successfully transported, such an event is recorded as a successful performance, and all parameters regarding the entire action are recorded as being associated with each other. When an unknown object is later acquired, the system may for example, determine the number of commonalities of such text description, product category, object manufacturer, object mass, object material, object shape, packaging details, object images, and object color information, or sensed information, object weight, object material, object shape, object opacity, object size, object volume, effector to be used, grip location, object movement limitations, object fragility, and object processing limitations.
In accordance with further embodiments, associations of commonalities may be generated that achieve performance of the task (successfully moving an object) such that the collection of parameters are recorded as having achieved a positive performance. Through such a reward feedback process, a system may learn from actions that do not achieve positive performance, and learn from actions that do achieve positive performance.
An object processing system in accordance with an embodiment, may provide a goods-to-robot product sorting system, in which bins are brought to a pick-and-place robot that must pick an object from one bin and place it into another. For example, each source bin may provide a homogeneous set of retail products, which was filled by an earlier process that decants vendor cases into bins. These bins might be conveyed directly to picking stations, stored in short-term buffer storage, or placed in an Automatic Storage and Retrieval System (AS/RS). As part of the decanting process, the product SKU is noted and a bin ID number is also noted, and the two numbers are associated in the facility management software database. The bins filled with items are sent back to the stores to replenish the store's stock of items. When a store order is processed, a set of source bins and a destination bin are routed to a picking station. The picking station could be automated with a robot, or it could be a manual picking station where a person does the handling.
There might be a variety of robot types for handling different item classes, or the robots might be capable of changing effectors, from one size vacuum cup to another, for example. The robots pick an object from the source bin, transport it to the destination bin, and drop or place the object therein. Following the operation, sensory information (including depth sensors, RGB cameras, flow sensors, pressure sensors, wrist-state, etc.) collected over the entire interaction is employed to determine whether the transfer operation was successful, and the type of failure when necessary, and this information is stored in the system database.
In addition to sensor information, manual feedback may be supplied by operators based on viewing the handling, where the operator, for example, selects a menu of items that could include “robot could move faster/slower,” or “it picked more than one item when it should have picked one,” or “was the grasp point ok?” or “the item was damaged,” or “the item was dropped too high.”
The perception unit 218 also includes scanning and receiving units 80, 82, as well as edge detection units 84 for capturing a variety of characteristics of a selected object of the whole bin.
In particular, the contents of the bin are volumetrically scanned as shown in
In accordance with further embodiments, the system may additionally employ edge detection sensors 84 that are employed (again together with the processing system 201), to detect edges of any objects in a bin, for example using data regarding any of intensity, shadow detection, or echo detection etc., and may be employed for example, to determine any of size, shape and/or contours as shown in
In accordance with further embodiments, the system may estimate a volume of an object while the object is being held by the end effector. Although with certain types of object processing systems (e.g., package sortation for shipping/mailing) volume may not be as helpful (for example when handling deformable plastic bags), in other systems such as store replenishment or e-commerce applications, volumetric scanning would be very valuable. In particular, the system may estimate a volume of picked item while being held by gripper, and compare the estimated volume with a known volume. One approach is to estimate the volume of the one or more items while the gripper is holding the object (or objects), and then compare the observed volume to the a priori known volume of the item. With reference to
As shown in
The scanning volume may be the volume above the area where the items are picked from; or the scanning volume may be strategically placed in between the picking location and the placing location to minimize travel time. Within the scanning volume, the system takes a snapshot of the volume of items held by the gripper. The volume could be estimated in a variety of ways depending on the sensor type as discussed above.
For example, if the sensors are cameras, then two or more cameras may be placed in a ring around the volume, directed slightly upward towards at a backlighting screen (as discussed above) that may be in the shape of sections of a torus, where the gripped volume is held in between all the cameras and the brightly lit white screen. The brightly lit screen backlights the one or more held objects, so that the interior volume is black. Each perception unit and associated illumination source may be activated in a sequence so that no two illumination sources are on at the same time. This allows easy segmentation of the held volume in the image.
The illumination may be provided as a particular wavelength that is not present in the room, or the illumination may be modulated and the detector may demodulate the received perception data so that only illumination from the associated source is provided. The black region once projected back into space, becomes a frustum and the objects are known to lie within a solid frustum. Each camera generates a separate frustum, with the property that the volume of the items is a subset of all of the frustums. The intersection of all the frustums yields an upper bound on the volume of the object(s). The addition of a camera improves the accuracy of the volume estimate. The gripper may be visible within the cameras, and because its position is known, its volume can be subtracted out of the frustum or volume estimate.
In accordance with other embodiments, 3D scanners may be used that obtain 3D images of the scanning volume, then the volume estimates are obtained in a similar way by fusing together the point clouds received from each sensor, but without the need for segmenting the images from the background using backlighting. Each 3D scanner returns a 3D image, which for each pixel in the image returns a depth, and again, may use any of light detection and ranging (LIDAR) scanners, pulsed time of flight cameras, continuous wave time of flight cameras, structured light cameras, or passive stereo cameras, etc.
In accordance with further embodiments, the system may detect multiple picks by automatically perceiving leaks from flow or pressure data. With reference to
There are several process parameters associated with these actions at several stages during the flow of goods through the overall material handling system, including (a) whether to use a human or a robot, (b) which type of robot, (c) which type of effector, (d) the method and parameters for the algorithms that choose a grasp point, (e) how aggressively or quickly the object can be moved with the robot arm, (f) how to determine the outcome of the motion, (g) sensor thresholds for various decisions such as whether the item is grasped or not based on vacuum seal, and (h) the method by which it plans a path to transfer the object.
The facility handles over many tens of thousands of SKUs. The problem of producing process parameters for each SKU is a challenge. Further, there may be thousands of new SKUs introduced every year, so an efficient process to associate process parameters with new SKUs is crucial. When a new SKU is introduced, a human worker scans an object in the vendor case, and that SKU is transmitted to the facility software system, e.g., operating on computer processing system or systems 201. The worker or system sensors might produce additional information, such as images, weight, and dimensions that are stored in the system software database. The system would also store information provided by the vendor, which may include a name, a text description, weight, dimensions, an image, and other information.
The classifier software then produces an initial estimation of parameters, which might take the form of several different probabilities pi, the probability that the item is in class i. It is possible that a new SKU may also introduce an entirely new class of items. When an object is handled for the first time, the initial process parameters are employed, and the outcome of the operation is saved. In the handling process, the system gains additional sensory information, which is saved in the system database. The outcome of the operation is also saved. If the initial grasp fails, the system might adjust the process parameters to discourage future grasps at the same location. If the object is dropped during the picking process, the system might adjust the motions to be less aggressive. If damage is noted, parameters might be adjusted for more careful drops, or a different picking station, or a different size vacuum cup.
A similar process is followed each time the object is handled, so that the system builds up in the database a record of all its experience. As this record grows, the item's class will be determined with greater confidence, and other information including process parameters will also be refined. This embodiment includes a number of variations. Within a single distribution center, through use of a common database, the experiences of all robots are shared. By linking distribution centers together, the experiences of all robots can be shared across the enterprise.
Another variation is that when the system is idle, or when the load is light, the system may request objects from the AS/RS, send the objects to various picking stations, gather more experience with the items, and refine the associated data. Another variation is that in addition or instead of the robot picking, the process parameters include which person is doing the manual picking. Person X may be more adept at handling small SKUs, and person Y may be more capable of lifting heavy items. The system learns from the person's throughput data which objects the person handles best and worst on an object-specific basis, and uses this information to route goods to manual stations, or manual stations and robotic stations and optimizes the warehouse-wide handling activity.
In accordance with a further embodiment, the invention provides a system in a shipping center. Objects may vary considerably, including boxes of different sizes and weight, polybags, padded mailers, envelopes, shipping tubes, and others. All the objects are sorted by destination, loaded into plastic bags, and these plastic bags are loaded into trailers. Some packages arrive at the facility from local vendors, including local E-commerce order fulfillment centers. Other packages arrive from other shipping centers. All these packages are loaded onto conveyors that carry the packages to robotic picking stations as discussed in more detail below. The robot is equipped with a variety of sensors including cameras and optical bar code scanners. In some cases, a bar code is visible allowing the system to retrieve the object's identity and associated information. In some other cases, cameras allow the system to estimate the item class and other information relevant to the picking operation.
The system 402 includes a perception unit 408, and with further reference to
The perception unit 408 includes scanning and receiving units 80, 82, as well as edge detection units 84 (as discussed above) for capturing a variety of characteristics of a selected object or the whole bin.
The volumetric scanning may again be done using scanning and receiving units 80, 82 together with the processing system 42, that send and receive signals, e.g., infrared signals. In accordance with an embodiment, the volume captured in
In accordance with further embodiments and with reference to
The carriage 430 is mounted via load cells 442, 444 on a frame 446, and it motion along a rail and in tipping, is controlled by actuation system 448. In particular, the pair of load cells 442, 444 are coupled to the frame 446, and the carriage body 432 is mounted to (and is suspended by) the load cells. By locating the load cells in the body of the carriage close to the object(s), a highly reliable weight measurement may be obtained. Once an object is detected by the beam-break transmitter and receiver pair 452, 454, the system in accordance with an embodiment, will average the weight value of the two load cells (W1, W2) together, double the result, and subtract the weight of the body 432. In this way, weight of objects may also be estimated. In accordance with other embodiments, the load cells themselves may register a change, indicating that the carriage as received or expelled an object.
Communication and electronic controls are provided by electronic processing and communication system 450. The carriage body 432 is adapted to be rotatable about an axis 447 (to empty its contents), and the carriage body 432 is attached to a top portion 449 of the load cells 442, 444 above the axis of rotation 447. Communication and electronic controls are provided by electronic processing and communication system 401 (shown in
With reference to
The object classification system 510 uses the first and second sets of information to assign a specific class to the item. The first set of information includes information that is sent along with the object. This first set of information can include the identifying indicia used by the identification system 510, as well as a text description of the object, the product category of the object, manufacturer information, information regarding the dimensions, shape, mass, volume, materials used, packaging or item information including colors, patters, images or other source indications, structural information such as deformability, fragility, required orientations (“This Side Up”), etc. A second set of information about the object can be determined by the system, for example using sensors to measure features such as mass, volume, dimensions, shape, stiffness, color, images, etc. It can also associate process variables to the object, such as effectors that can be used with the object, motion or inertial characteristics of the object that would affect processing, acceptable drop heights or orientations when releasing the object, or other time, temperature, or handling details.
The class information assigned by the classification system 510, in turn, defines processing parameters including the type and manner of processing that occurs at an object processing station 402. The type and manner of processing can include specific grasp-planning methods that can target, for example, placement on the object associated with the object's center of mass, or information related to flat areas on the object that can be grasped by a vacuum cup, or an indication that an explorative trial and error grasp methodology is required to find an appropriate grasp location. The processing parameters can also indicate various motion planning methodologies that balance the speed of the effector moving the object with the ability to maintain the object in the effector's grasp. The processing parameters may also include information related to releasing the object from the effector, including release height, release orientation, release location, etc. These processing parameters can indicate specific processing methods or hardware needs available at some but not all object processing stations 402. For example, a particularly heavy object may require a larger vacuum cup attached that is found at only a single object processing station. Alternatively, particularly fragile object might be assigned to a specific person at a manual object processing station, and objects that require another skillset may go to a different person at a manual processing station. A manual pick station 700 is shown in
The processing control system 500 also includes a routing system 550 that routes an object from its supply location to a selected item processing station 402. The routing system 550 uses the class information provided by the object classification system 510 along with system information 556 to determine an optimal destination and route to the destination. The routing system 550 takes object processing station information, such as object queue, station hardware, station distance, and estimated travel time to the station to optimize routing. Routing information 555 is then sent to the system to be used.
As the object is sent to the object processing station and while it is being processed according to the determined processing parameters, evaluation information 575 is sent from system inputs 570 are used by the evaluation system 560 to evaluate the chosen class and routing information. The system inputs 570 can include inputs from sensors, such as depth sensors, 3d Cameras, RGB cameras, flow sensors, pressure sensors, positional or force sensors attached to the effector, weight sensors, microphones, or other feedback sensors to evaluate whether the interaction of the system with the object is successful or unsuccessful. System inputs can also be manually entered into the system by an operator witnessing the routing and object processing station interaction. For example, if an observing person sees that an object looks very securely held by an effector, and can likely be processed faster, the person can send that feedback through the system. A successful interaction can be one that occurred as expected and intended, within expected or desirable tolerances and thresholds, and without perceived damage. An unsuccessful interaction may be one that experienced failed grasping during initial engagement, failed grasping during transit, damage to the object, unintended collision of the effector or object with another object or structure, or interactions that exceeded expected or desirable tolerances and thresholds.
The successful or unsuccessful interactions can be quantified with a score that indicates how successful or unsuccessful an interaction was. This score can be based on sensory input, threshold proximity, target processing times versus actual processing times, routing times, object breakage, or other measurable information. The scores can then be used by the object classification system 510 to reclassify the object.
Whether the interactions are successful or unsuccessful, the processing parameters may be changed by the object classification system. For example, after a successful interaction, in an attempt to either increase speed or efficiency by trying different effectors, the object classification system may assign a different class to the object that allows for faster or riskier motion planning, less precise grasp planning, higher and less precise release characteristics can be implemented. After an unsuccessful interaction, a new class may be assigned that uses different processing parameters that are more likely to be successful.
As the system continues to process objects, the assigned class for the object will be assigned with greater likelihood of success. As new objects enter the system, the object classification system 510 can compare the new object's information with previously processed objects' information having comparable characteristics to choose a class for the new object with a higher chance of having a successful interaction at a chosen object processing station.
As an example, a substantial number of objects may be from a particular retailer that specializes in smart phone cases, and ships them all in packages that present particular challenges to the robotic picking stations. The packages are distinctively colored and easily recognizable, enabling the system to identify these items and handle them in a manner to assure a firm grip and a careful motion.
As another example, there is a great degree of standardization in paperboard envelopes, and in padded mailers. It is possible to classify an object from camera images, and infer its handling properties based on experience gained across the entire class. In this embodiment, the system is able to learn from experience based on recognizable patterns in package appearance, even in the absence of SKUs. The system is also able to use experience it gains with a single object. As an object makes its way through the network, it may pass through several shipping centers, and be sorted many times. When the bar code is acquired, and when the item is not making its first appearance in the system, the experience of previous handling is now available to select the correct process parameters.
In accordance with various embodiments, different use cases may be provided as follows. As an example involving introducing a new SKU in a distribution center, suppose that a cereal distributor has introduced a variation on the packaging of a popular breakfast cereal. The only change might be that a local sports hero appears on the box. When a bin with several of these items is introduced to the system, the system uses the bar code to get the SKU, and the associated product information. Based on this information, the system correctly classifies the product as a cereal box, identical in its handling properties with several cereal boxes already well known to the system. The system is immediately able to process the new SKU, based on its experience with similar products, and its ability to correctly recognize that similarity.
As described above, the classification process occurs autonomously without human participation. Alternatively, this classification process might be performed when a human worker presents the new SKU to the system, giving the human an opportunity to confirm or correct the classification.
In another example involving re-classifying an item based on a data obtained during processing, a new SKU may have been introduced and classified as a cereal box, as described above. However, due to new packaging of the SKU, the dimensions have changed, and must be grasped using a small cup size. Because the system has never seen that SKU before, it will use the process parameters of the previous SKU. After the first unsuccessful pick of the SKU, the system will update its estimated parameters away from its original prior.
At the same time, this change in the classification structure can be applied to other objects that have been introduced to the system, but have not yet been routed to picking stations with cameras. So, when a distributor introduces new packaging for an entire line of products, the system might not have to look at each item, but can make reasonable inferences just from examining the first such item.
In another example involving learning to avoid placing a suction cup on a seam, there are several SKUs, shampoo bottles in several varieties corresponding to dry hair, oily hair, fresh scent, herbal, and so on. All of them are packaged in the same type of bottle. As these shampoos are processed, occasionally the suction gripper is placed at the seam between lid and bottle, which is virtually invisible to the system's perception system. When these grips fail, the system can determine this from imagery of the destination bin, from pressure sensing in the effector, from a force/torque sensor in the wrist, or a combination of these sensors. The system notes the location of the failed grasp, and adjusts downward the expectation of a good grasp in the vicinity. Thus the system learns better grasp behaviors, for all items in the class, and it does so quickly since it can aggregate experience gained across the entire class.
In another example involving learning a better motion, several SKUs may be packaged similarly as bottles enclosed in paperboard boxes. Often the boxes arrive at a picking station standing side by side in the bin, and must be grasped by a suction cup placed on the top of the box, which is a hinged lid. The robot obtains a secure grasp, and lifts the box clear of the other boxes in the bin. Then the robot begins a motion to transport the box to the destination bin. Depending on that trajectory, including the acceleration, the tipping of the effector, and the orientation of the box, the lid sometimes comes open. The system detects this event from imagery and force/torque data. The system adjusts the motion to a more conservative motion, keeping the center of mass centered under the suction cup, by maintaining a more upright angle of the effector.
In another example involving learning to avoid damage, suppose a new SKU is introduced, but on occasion, perhaps one time in five, the product is damaged when it is dropped into a destination bin. The violence of the drop might be exacerbated by the oscillation of the heavy item suspended from the bellows cup. In this case, the outcome might not be observable to the system's sensors, but might be observed and reported by human workers as input to the system. The system modifies the dropping action, moving the effector closer to the destination bin, and timing the release so that the object's oscillation is at its nadir.
In a further example involving learning to use a new effector, a certain class of items may be usually handled well, but perhaps some of the items are heavier than average. The system has learned to handle them without dropping by moving more slowly, but this results in lower productivity. The engineering team introduces an additional robotic picking station with a larger suction cup. As items are routed to the new station, a variety of items and motions are employed, and based on observed outcomes the system learns which items are suited to the new effector, and which motions are acceptable. In the end, the heavier items are now handled quickly and productivity is restored. In addition, when a new effector is introduced, its characteristics might be manually entered, to speed up the process by which the system integrates the new effector in operations.
In a further example involving learning to recognize outcomes, a variety of sensors may be used to detect success or failure, and type of failure. These include pressure sensors, force/torque sensors, and image sensors. There are software procedures to process these sensor signals to recognize the outcome. These software procedures can be refined by using the information obtained by one sensor to improve another sensor, or by using the outcome determined by a fusion of the sensors. As a simple example, imagine that failure is being signaled by a change in sensed pressure, but after several examples it becomes evident from other data that the pressure sensor is signaling the failure a bit late. The signal processing, a feature or set of features, or a threshold, might be adjusted to advance the detection of failure by the pressure sensor.
In a further example involving learning to detect anomalies, trash may sometimes enter a vacuum gripper, and lodge against a screen, reducing the effector's effectiveness. Anomaly detection software might note when sensory signals stray outside of a given region. When the source of an anomaly is identified, such as when human operators note that trash has entered a vacuum gripper, the anomaly detection software may then adjust itself to correctly classify future such anomalies, and alert human operators in a more timely fashion.
In a further example involving learning to interpret force/torque sensors, the force/torque sensor picks up signals from a variety of sources. The vacuum supply hose moves around, and its motion varies with robot motion and with hose pressure. The item moves around, and sometimes the contents are lose and move around within the item. There are time constants and other characteristics associated with these signals, which presents an opportunity to put signal processing into place that is tuned for the particular item, and to reject the noise.
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.
The present application claims priority to U.S. Provisional Patent Application Ser. No. 62/750,777 filed Oct. 25, 2018, as well as to U.S. Provisional Patent Application Ser. No. 62/865,421 filed Jun. 24, 2019, the disclosures of which are hereby incorporated by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| 62750777 | Oct 2018 | US | |
| 62865421 | Jun 2019 | US |
