Until last year, autonomous container unloading of containers and trailers was one of the remaining “holy grail” applications for the automated warehouse. Every logistics and distribution center depends on ingesting new items, which typically arrive at the loading dock in trailers or shipping containers.
In most cases, human workers must deal with the repetitive task of unloading heavy or uneven packages or pallets and relaying the goods into warehouses in all kinds of temperatures.
Container unloading is an optimization game
Space is at a premium for containers shipped overseas and as a result, they are floor-loaded and packed as tightly as possible to use every bit of space. The key to optimizing space usage is that boxes are stacked from floor to ceiling and must be unpacked by pulling each one from its location within the container.
Another important logistics use case is the shipment of mixed-load and unit-load pallets within trailers and containers. This packing format is typically used for distribution warehouses that are moving pallets of items from a central warehouse to individual retail stores.
Unpacking trailers and containers with automation has been difficult for several reasons:
- No two containers or trailers are packed the same, meaning that unpacking requires the ability to perceive where each box or pallet is located.
- Items move, shift, and settle during shipping. Even well-packed trailers can arrive at their destination in a chaotic form.
- The unpacking task is difficult due to repetitive lifting tasks, and the environmental conditions on the loading dock and inside of the containers can be extremely hot, cold, or humid.
Three different approaches have emerged for robots to solve the container unloading problem.
- Mobile manipulators
- Articulating conveyors
- Autonomous fork trucks/platforms
Mobile manipulators
The first solution type is based on mounting a robotic manipulator or two onto an autonomous mobile robot (AMR) base. The mobile manipulator then moves into the trailer and uses large vacuum grippers to unpack the boxes from the trailer onto a flexible conveyor.
The outfeed conveyor singulates the boxes and brings them onto the loading dock. Suppliers of such systems claim that they can be easily redeployed to multiple bays on a loading dock.
Boston Dynamics – Stretch
Boston Dynamics showed off its Stretch case-handling robot at MODEX 2022. Stretch demonstrated its container unloading capabilities, although it only worked with limited box variations. Stretch has been successfully deployed at customer sites, with more customers in the pipeline according to Boston Dynamics.
The company appears to have even grander aspirations for the robot in the coming years. During the demonstration, a video showcased animated Stretch robots swiftly moving around a warehouse, assembling pallets on top of AMRs. These pallets were then transported to other Stretch robots, which efficiently loaded the boxes into a truck.
In June 2021, Hyundai completed its $880 million acquisition of Boston Dynamics from SoftBank, valuing the company at $1.1 billion. More recently, Boston Dynamics added Multipick functionality to Stretch in November.
Pickle Robots – Unload
The Pickle Robot Unload system is built around a mobile manipulator that uses vacuum grippers to acquire boxes and send them to a flexible outfeed conveyor. Pickle Robot has raised a total of $37.5 million, according to Crunchbase.
Pickle Robot recently announced a partnership with Yusen Logistics to streamline container unloading. The Cambridge, Mass.-based company began working alongside the logistics provider in September, focusing on processing import freight at its transload facility in Long Beach, Calif. Yusen is deploying Pickle Unload systems with a robotics-as-a-service (RaaS) model.
Dexterity – DexR
Truck loading within parcel hubs is challenging because of the decision-making process required to stack shipments varying in size, shape, weight, and packaging material. Prior technologies have struggled to meet the complex demands inherent in the FedEx network’s operations, leaving loading as a labor-intensive and inefficient task.
Dexterity Inc.‘s proprietary DexR mobile robots are agile enough to swiftly navigate to the rear of trailers and can connect to powered conveyor systems. Boxes are delivered at the end of an outfeed conveyor stationed in the loading dock.
Dexterity said its AI platform is designed to handle truck loading operations with real-time wall planning, force control, and machine learning algorithms. It provides a sense of touch for optimal packing density and motion planning for swift operation.
FedEx and Sagawa Express are testing this technology for commercial deployment. Redwood City, Calif.-based Dexterity was founded in 2017 and has raised a total of $196.2 million, reported Crunchbase.
Rightbot
Rightbot Technologies Inc. said it specializes in unstructured load handling. its autonomous trailer/container unloading system uses a vacuum gripper to unpack the load in a container and outfeed the boxes into the loading dock.
Founded in 2020, the Newark, N.J.-based company has raised a total of $6.9 million.
Anyware Robotics – Pixmo
Anyware Robotics recently came out of stealth mode and announced its Pixmo mobile manipulator for trailer unloading. The startup told Mobile Robot Guide that it has already fielded its first unit at an early customer site, where it is going through the paces.
The mobile manipulator at the heart of Pixmo is a FANUC collaborative robot with a 30 kg (66 lb.) payload capability. It uses a 3D camera mounted on a mast to perceive the box locations in the trailer and guide the robot arm.
An onboard vacuum pump runs the vacuum gripper to pick up boxes in the container. Pixmo can place boxes onto an outbound, flexible conveyor that delivers the boxes outside of the trailer or container, explained the Fremont, Calif.-based company.
Anyware Robotics recently announced a vertical lift add-on and said its software could enable Pixmo to be useful for other warehouse applications in the future.
Contoro Robotics
Austin TX TX-based Contoro Robotics was founded in 2022. Contoro’s solution is fully self-contained and battery-powered, including the vacuum pump for the gripper. The mobile manipulator maneuvers the robot into the container as it unloads layers of boxes, and can operate for 8 hours straight on a single charge. The robot arm has a reach of 2.5m, and the current gripper is designed to handle boxes ranging from 12 to 22 inches (30 – 56 cm) in size, with a maximum weight capacity of 40 pounds (18kg).
Similar to the other mobile manipulator-based solutions on the market, the robot pulls boxes out of the packed layer onto an outfeed conveyor which brings the boxes to a location deeper in the loading dock.
The company has raised a total of $8.5M according to Crunchbase.
Articulating conveyors for container unloading
The second type of robot for container unloading combines an active conveyor and grippers that can acquire boxes directly from the stacked location onto an outfeed conveyor that then singulates the boxes into the shipping dock.
Such systems are large and take up a lot of space on the loading dock. As a result, they are likely to remain dedicated to a specific bay on the loading dock, with multiple units deployed to multiple bays.
Mujin – TruckBot
Mujin Inc. unveiled TruckBot at ProMat 2023. The system is designed to continuously unload containers and deliver boxes out of a container to a Mujin palletizing robot for induction into the warehouse.
The company claimed that TruckBot can unload both truck trailers and shipping containers at a rate of up to 1,000 cases per hour. It attaches to standard telescoping conveyors found at many existing loading docks.
TruckBot can reach up to 52 ft. (15.8 m) into a truck trailer or shipping container and can handle boxes weighing up to 50 lb. (22.7 kg), including containers with packing complexities and mixed-SKU loads, said Mujin.
TruckBot is powered by the MujinController, a software platform that enables it to work autonomously, planning the most efficient paths and movements while minimizing idle time and maximizing productivity. Founded in 2011, Tokyo-based Mujin has raised a total of $157.9 million.
Honeywell – Robotic Unloader
The Honeywell Robotic Unloader uses advanced vision-guided robots, machine learning, and integrated controls and conveyors to automate the freight-unloading process. The machine is fully autonomous and doesn’t require an operator to remain on standby. Honeywell introduced the system in 2019.
Honeywell specified that its Robotic Unloader can handle individual cases up to 75 lb. (34 kg) and multiple cases simultaneously up to 350 lb. (158.7 kg). A robust operating algorithm, integrated unscrambler, and dynamic side guides are intended to minimize jams.
These robots can handle a variety of case sizes and weights using a vacuum arm and conveyor sweep system, even in trailers not designed for container unloading, said Honeywell. Machine learning techniques allow these robots to discharge goods in a semi-singulated flow, improving downstream operations without fleet adjustments, it added.
Autonomous pallet unloading
The third system type involves an autonomous fork truck or platform that can drive itself into a trailer, acquire a pallet, and remove the pallet from the trailer to a staging or depalletizing point on the loading dock. Note that this technology is viable only for containers packed with items on pallets.
Fox Robotics – FoxBot ATL
In 2019, Fox Robotics introduced FoxBot ATL, a Class 1 electric, stand-up autonomous forklift build for loading and unloading operations on warehouse loading docks. This AMR uses sensors to autonomously enter a container or trailer, locate and acquire a loaded pallet, and remove it from shipping to the ingestion location.
FoxBot ATL offers significant labor cost savings, improved worker safety, speedy unloading, reduced product loss, and increased uptime, claimed Fox Robotics. Its software can manage up to six autonomous forklifts simultaneously, eliminating hazardous environments.
The Austin, Texas-based company said the self-driving lift truck uses advanced sensors and proprietary software to navigate warehouse floors with precision. Its 360-degree monitoring, lidar sensors, and safety braking systems provide safety, said Fox Robotics, which has raised $33 million, according to Crunchbase.
Gideon – Trey
Osijek, Croatia-based Gideon Brothers last year released the Trey self-driving forklift, which is designed to autonomously load and unload pallets from truck trailers.
Trey integrates Gideon’s proprietary autonomy technology, driven by AI and 3D vision, with software for intelligent workflow management, all housed within a chassis engineered by Infinity Machine & Engineering Corp.
Gideon’s system includes stereovision cameras, deep learning algorithms, and computer vision to navigate complex loading docks safely. A single Trey robot can unload trailers at multiple bays, with a single operator to manage its tasks, according to Gideon.
The system is designed only for pallet-mounted cargo and it is not appropriate for floor-loaded containers or trailers. Gideon was founded in 2017 and has raised $37.7 million to date.
Slip Robotics – ATLS
Slip Robotics showcased its Automated Trailer Loading/Unloading System (ATLS) at ProMat 2023, featuring an omnidirectional robot capable of accommodating up to eight full pallets and 6 tons of weight. The system integrates seamlessly into transportation workflows, maximizing space utilization.
The Slip ATLS streamlines loading and unloading processes by eliminating the need for fork-truck operators, resulting in safety enhancements and time savings. This can optimize logistics operations, reducing driver waiting times from 1.5 hours to 5 minutes, said the company.
The automated robot accompanies loads to their destinations, ensuring minimal downtime and maximized throughput, claimed Slip Robotics. It can optimize loading bays by deploying sets of three robots per bay, facilitating seamless transitions between trailer arrivals and optimizing overall operational efficiency.
Atlanta-based Slip Robotics was founded in 2019 and has raised a total of $16.4 million, said Crunchbase.
One container unloading vendor has already called it quits
Memphis-based Dextrous Robotics recently shut down after developing a robot designed to unload boxes from trailers using a chopstick-like mechanism.
Evan Drumwright and Sam Zapolsky co-founded Dextrous in 2019. The startup had secured approximately $8 million in funding since its establishment. Unfortunately, the company faced challenges in securing additional funding to kickstart production of the commercial version of its DX-1 robot.
Suzanne Drumwright, the director of operations at Dextrous Robotics, emphasized that the DX-1 robot was fully tailored to specific needs. The container unloading system used few off-the-shelf components. The cost of materials for each unit exceeded $300,000.
