Abstract
An automated goods-to-person picking station is described, featuring dual presentation bays and a shadowed pick face to enhance picking efficiency. This arrangement addresses the problem of operator idle time incurred while waiting for a subsequent item tote to be presented. By utilizing a bay alternation logic and pre-fetching the next required tote into a ready bay while the operator is actively picking from the other, continuous operation is facilitated. The system incorporates visual indicators at the pick face to guide the operator, and includes mechanisms to manage situations where material retrieval rates fall below the operator's picking pace.
1. Technical Field
[0001]This disclosure relates generally to automated material handling systems, and more specifically to goods-to-person picking stations designed for order fulfillment operations. The technical field encompasses the design and operation of workstations where individual items are retrieved from storage units and consolidated into orders for outbound shipment or further processing.
2. Technical Context
[0002]In many modern order fulfillment environments, goods-to-person systems are employed to improve picking efficiency and reduce manual travel time. These systems typically deliver storage units, such as totes or cartons, containing various stock keeping units (SKUs) directly to an operator at a fixed picking station. A common challenge in such systems is the idle time experienced by the operator while a robotic or automated storage and retrieval system (AS/RS) retrieves the next storage unit and transports it to the picking station. This waiting period directly impacts the overall pick rate and system throughput. Minimizing this non-value-added time is a critical objective for maximizing operational efficiency and achieving design throughput targets for the picking process.
3. System Overview
[0003]The disclosed arrangement is a goods-to-person picking station (10) designed to mitigate operator idle time. The station incorporates two distinct presentation bays (12, 14), each capable of presenting a storage unit (16) for picking. While an operator (18) is actively picking items from a storage unit (16) in a first presentation bay (12), the system concurrently pre-fetches the next required storage unit (16) and stages it in a second presentation bay (14). This pre-staging creates a shadowed pick face, meaning the next picking task is ready before the current one concludes. A control system (20) orchestrates the movement of storage units (16) and manages the picking workflow, including bay alternation logic, item presentation, and visual guidance to the operator (18). The system is designed to provide a continuous flow of work, thereby increasing the effective pick rate of the operator (18) by minimizing or eliminating the wait between picking tasks.
4. Components
[0004]The goods-to-person picking station (10) comprises several key components, as illustrated in FIG. 1, which work in concert to facilitate continuous picking. A conveyor system (22) or similar material transport mechanism delivers storage units (16) to the picking station (10) and removes empty or partially picked storage units (16). The picking station (10) features two presentation bays: a first presentation bay (12) and a second presentation bay (14). Each presentation bay (12, 14) includes a support surface (24) for the storage unit (16), which may be a roller bed, a conveyor segment, or a static platform. Associated with each presentation bay (12, 14) are pick-to-light indicators (26), which illuminate to direct the operator (18) to the correct item within the storage unit (16) and specify the quantity to be picked. A put-to-light display (28) guides the operator (18) in placing picked items into an order container (30), which is typically staged on an adjacent order container support (32). A confirmation sensor (34), such as a light curtain or proximity sensor, is positioned near each presentation bay (12, 14) to detect when an operator (18) has accessed a storage unit (16) or completed a pick. An operator interface (36), which may include a touchscreen or push buttons, allows the operator (18) to confirm task completion or signal exceptions. The overarching control system (20) manages the inventory, order queues, material flow, and the logic for bay alternation and pre-fetching. This control system (20) interfaces with the conveyor system (22), pick-to-light indicators (26), put-to-light displays (28), confirmation sensors (34), and the operator interface (36). Buffer lanes (38), as depicted in FIG. 2, are integrated upstream of the presentation bays (12, 14) to temporarily hold incoming storage units (16) that are awaiting presentation, ensuring a continuous supply.
5. Operation
[0005]Operation of the picking station (10) commences with the control system (20) identifying the next required storage unit (16) for an active order. At start-up, the control system (20) directs the conveyor system (22) to deliver a first storage unit (16a) to the first presentation bay (12) and a second storage unit (16b) to the second presentation bay (14). Once 16a is positioned, the pick-to-light indicators (26) associated with the first presentation bay (12) illuminate to direct the operator (18) to the specific item and quantity to be picked from 16a. Concurrently, the put-to-light display (28) indicates where the picked item should be placed into the order container (30). The operator (18) performs the pick, and the confirmation sensor (34) detects the completion of the task, or the operator (18) confirms via the operator interface (36).
[0006]Upon confirmation of a pick from the first presentation bay (12), the control system (20) immediately prepares for the next pick. While the operator (18) is still engaged with 16a, the system begins presenting 16b in the second presentation bay (14). Once all picks from 16a are complete, and the operator (18) confirms task completion for 16a, the pick-to-light indicators (26) for the first presentation bay (12) are extinguished. The control system (20) then activates the pick-to-light indicators (26) for the second presentation bay (14), guiding the operator (18) to begin picking from 16b. Simultaneously, the now empty or depleted 16a is released from the first presentation bay (12) onto the conveyor system (22) for removal, and the control system (20) initiates the pre-fetching of the next required storage unit (16c) to be staged in the first presentation bay (12). This alternation between bays ensures that as soon as the operator (18) finishes with one storage unit (16), the next is already presented and ready for picking.
[0007]Should the retrieval system fall behind the operator's (18) picking pace, meaning a subsequent storage unit (16) is not yet available in the alternate bay when required, the control system (20) issues a visual or audible alert to the operator (18) via the operator interface (36) or dedicated status indicators (not shown). In this scenario, the operator (18) may experience a brief waiting period until the next storage unit (16) arrives. The system is designed to minimize such occurrences through optimized pre-fetching algorithms and adequate buffering capacity in the buffer lanes (38). On fault or interruption, such as a conveyor jam or a system error, the control system (20) halts all material movement and picking operations, illuminates relevant fault indicators, and logs the event for diagnostic purposes. Operator (18) interaction through the interface (36) can trigger an emergency stop or report issues. Picking resumes only after the fault is cleared and the system is reset.
6. Example Embodiments
[0008]Embodiment 1 In this embodiment, the two presentation bays (12, 14) are arranged side-by-side, directly in front of the operator (18). The conveyor system (22) feeds storage units (16) from a central input line, which then diverges to supply each bay. An output line collects depleted storage units (16) from both bays. The pick-to-light indicators (26) are mounted on the storage unit (16) support surface (24) for each bay. The operator interface (36) is centrally located between the two bays, facilitating easy access regardless of which bay is active. This configuration aims for minimal operator movement between active picking locations.
[0009]Embodiment 2 This embodiment positions the two presentation bays (12, 14) in a staggered or angled arrangement relative to the operator (18), forming a 'V' shape. This ergonomic configuration may reduce the operator's (18) torso rotation required to access items at the rear of a storage unit (16). The input and output conveyor segments for each bay are designed to accommodate the angled approach and departure of storage units (16). The pick-to-light indicators (26) are mounted on a gantry (40) above the presentation bays (12, 14), providing visibility from various operator positions. The confirmation sensor (34) is a light curtain spanning the front of each bay, detecting hand entry.
[0010]Embodiment 3 In this embodiment, the presentation bays (12, 14) are vertically stacked, with one bay positioned above the other. This configuration conserves horizontal floor space. A lift mechanism (not shown) is integrated into the conveyor system (22) to elevate or lower storage units (16) to the appropriate presentation bay (12, 14) level. The operator (18) may utilize a height-adjustable platform (not shown) to maintain an ergonomic picking posture for both levels. Pick-to-light indicators (26) are affixed to the vertical frame supporting the bays. This embodiment is particularly suited for facilities with high space utilization requirements and a design specification for smaller station footprints.
7. Alternative Configurations
[0011]Instead of a conveyor system (22) for material transport, automated guided vehicles (AGVs) or autonomous mobile robots (AMRs) could deliver storage units (16) to and from the presentation bays (12, 14). Each presentation bay (12, 14) could be equipped with a robotic arm to assist in item extraction, particularly for heavy or awkwardly shaped items, reducing manual effort. The pick-to-light indicators (26) could be augmented or replaced by projected light patterns directly onto the storage unit (16) or item, indicating the pick location and quantity. For the put-to-light display (28), a dynamic projection system could indicate the specific cell within the order container (30) for item placement. The confirmation sensor (34) could employ vision-based systems to detect item removal and count the quantity picked, thereby eliminating the need for manual confirmation.
8. Parameter Variations
| Parameter | Realistic Range | Effect of Increasing Value | Effect of Decreasing Value |
|---|---|---|---|
| Storage Unit Size | 300 x 400 to 600 x 800 mm | Accommodates larger items or more items per unit, potentially reducing total storage units required per order. | Limits item size, potentially increasing the number of storage units needed to fulfill an order. |
| Conveyor Speed | 0.2 to 1.5 m/s | Faster delivery of storage units, reducing pre-fetch time and risk of operator wait. | Slower delivery, increasing pre-fetch time and potential for operator idle time if not buffered. |
| Buffer Lane Capacity | 2 to 10 storage units | Higher capacity reduces sensitivity to upstream delivery fluctuations, increasing system resilience. | Lower capacity makes system more susceptible to upstream delays, increasing idle time risk. |
| Pick-to-Light Brightness | 100 to 500 lux | Enhanced visibility in well-lit environments, improving operator reaction time. | Reduced visibility, potentially slowing pick identification and increasing errors. |
| Bay Separation Distance | 0.5 to 1.5 m | Greater separation may require more operator movement, but allows larger presentation bays. | Closer bays reduce operator movement but constrain bay size and accessibility. |
9. Additional Implementations
[0013]Further implementations of the goods-to-person station (10) could include integrated weighing scales (42) at each presentation bay (12, 14) or at the order container support (32) to verify pick accuracy by weight, as shown in FIG. 3. This enables immediate detection of short or over-picks. The station could also incorporate automated label printing and application equipment (not shown) for applying shipping labels or product identification labels directly to picked items or order containers (30). For returns processing, the dual bays could be configured to process incoming returns in one bay while presenting items for outbound orders in the other, thereby enabling a flexible operational mode. Furthermore, integration with augmented reality (AR) headsets could provide operators with heads-up displays indicating pick locations, quantities, and put destinations, potentially overlaying this information directly onto their field of view. This could replace or supplement the pick-to-light and put-to-light systems, offering a more immersive and flexible guidance system for the operator (18).
10. Figures
