While most AGVs are operated in indoor environments, there is a growing number of use cases in outdoor environments. Many applications resemble their counterparts in indoor manufacturing environments; but introduce more challenges for the sensors, robot localization, and robot control due to larger operating space, fewer landmarks, and a higher number of disturbances like sunlight, rain surface, or surface irregularities.
Types of operations carried out by the robot
Autonomous guided vehicles for transportation of ISO standard cargo containers in port environments have been put into practice. Basic requirements include the control of the large chassis, which is usually driven and steered by a diesel-hydraulic power set. The vehicle moves on pneumatic wheels over unprepared road surfaces at speeds of up to 6 m/s. As a rule, the fleet of autonomous vehicles, especially for performing standard tasks, should be controlled by a fleet management system to ensure maximum capacity. Other applications of robots in outdoor logistics include automatic truck control for transporting Euro pallets or waste.
Level of distribution
Logistics companies are looking for ways to reduce congestion and improve safety in yards. The combination of classic forklifts and trucks, as well as pedestrians in the yard environment, can make maneuvering difficult, dangerous, and inefficient. Therefore, self-driving vehicles could provide a great solution by executing all types of yard logistics including maneuvering and repositioning transport items, such as pallets and swap bodies. If we take another step into the sphere of logistics operations in the open air, then modern developments are focused on intercity cargo transportation, where trucks are usually applied. It led to the development of assisted highway trucking systems. A truck equipped with this capability will stay in lane automatically, keeping a safe distance from the vehicle in front and obeying the truck’s maximum speed and/or prescribed speed limits along the highway. The driver would still be required to perform tasks, such as: merging into traffic, overtaking, and leaving the highway, although, in the future, these functions could also be automated. Between indoor and outdoor delivery, there are AGVs for the automatic parking of cars in multi-story parking lots installed by suppliers Serva transport systems and Stanley Robotics (France). Both systems are designed as large forklifts to pick up the cars. By contrast, MHE-Demag created an AGV, which is entirely flat and can drive fully under the car. Outdoor AGVs achieve high-speed container transport between quay and stack-yard. In 2005, the Brisbane AutoStrad terminal started the presentation robotized Kalmar E-Drive straddle carriers, purpose-built for unmanned operations. A fleet of 27 free-ranging machines with 65 tons safe working load (SWL) was fitted with motion control and navigation systems that allowed them to operate round-the-clock in practically all weather conditions. Meanwhile, the installations have expanded and include, among others, the Sydney Port Botany and Ports of Auckland (NZ) as well. In 2019, Kalmar’s manufacturer Cargotec started offering automated truck handling. A pioneering example is the Hamburg Container Terminal Altenwerder (Germany), where Konecranes Gottwald Port Technologies reported the deployment of more than 84 outdoor electrically operated AGVs, ten vehicles are reported to be purely electrically driven (instead of diesel-electric transmission). Navigation is based on 19,000 transponders that are installed in the ground. It highly increases the speed and efficiency of container handling in comparison to traditional transport methods using trucks and cranes. The port ordered 25 AGVs in 2017. Konecranes Gottwald expanded to ports worldwide, including 72 AGVs in the Long Beach Container. Terminal in Los Angeles County with 30 additional vehicles ordered in 2020. One step even further is the using automated container stacking cranes as the link between quayside and landside equipment, such as ship-to-shore cranes, transport vehicles, and trucks. The 3E-D18 is Honda’s (Japan) AI-equipped outdoor mobile platform. By replacing the upper attachment, the 3E-D18 can perform various tasks: such as firefighting, farm work, and sports training support. Its off-road capabilities allow autonomous operation on rugged terrains, such as farms and mountains. The Segway Loomo of Segway Robotics (China) is derived from the former Segway Personal Transporter. In- and outdoor robots can be built upon these platforms based on their developer program. The Anymal C of Anybotics (Switzerland) is a multi-purpose legged outdoor platform capable of moving and operating autonomously in challenging terrain while interacting safely with the environment.
Cost-benefit considerations and marketing challenges
Due to the high complexity of outdoor robotics applications, these robots are mostly highly specialized in the tasks they perform and the environments they operate in. Therefore, it is still difficult to buy an outdoor robot off the shelf and apply it in different types of environments. The need for specialization drives up the costs of the robot application; however, outdoor environments also provide advantages as there is most often more space to move around and less traffic.