Challenges and requirements in the introduction of automated loading and unloading

Other conference contribution, 2022

Research question
The use of autonomous vehicles for road transport holds a potential to improve transport performance within areas such as safety, sustainability, driver shortage, and cost efficiency, and there is an increasing interest in the area (Sindi and Woodman, 2021). However, to fully realise the potential of autonomous transport, it seems that the interfaces with shipping and receiving facilities, in terms of loading and unloading, should be automated too, as argued below.In traditional setups, the truck driver is often responsible for loading and unloading the truck, as well as for securing the load. Hence, if there is no truck driver, a different solution is required. A straightforward solution would be for the personnel in the facilities to perform the loading and unloading. Increasingly, however, automation is applied also in production (Bortolini et al. 2021) and warehousing (Custodio and Machado 2020), and it is therefore not obvious that there will be personnel available at the pickup or delivery locations either. Moreover, it is not uncommon that facilities are manned only during daytime. Automated loading and unloading operations could make it possible to decouple the truck transports from the operations in the facilities, thereby enabling round the clock deliveries, regardless of the manning of the facilities. This could reduce congestion on the road. The application of automation often holds a potential to reduce operational cost, as the cost of man-hours may be reduced, which has been indicated in research on internal transport (Bechtsis et al. 2017), as well as the broader area of materials handling. There are several potential challenges that need to be overcome, and several requirements that need to be fulfilled, to enable automated loading and unloading between the autonomous transport and the shipping and receiving facilities. The loading and unloading processes can be considered to take place in the interface between different systems, linking the shipping facilities with the external transport, and linking the external transport with the receiving facilities. In addition to moving the goods onto and off the truck, there are further activities that need to be undertaken, which are performed manually in most systems today. This includes for example opening and closing the hatch of the truck and, importantly, securing the load on the truck after loading it. Applying a systems approach, this paper addresses the question: which are the challenges and requirements of automated loading and unloading in a setting of autonomous freight road transport?

Brief overview of the state of the art, including relevant references
Significant research in past focused on simulating and automating loading and unloading operations on transportation system with truck driver (Shen et al. 2019; Cao and Dou 2021). They are primarily focused on planning of loading and unloading system and defining the working principles of systemsmodules compatible with multiple material, For instance, Xu et al. (2021). Stacking of standard pallets on truck with fully automated forklifts (Cao and Dou 2021), design and development of automatic cargo batch system for loading and unloading operations (Lee et al. 2014), design and development of automated guided vehicle for material handing in production (Thylén 2022) and application of digital twin technology in design and develop of an intelligent control system for automatic loading and unloading (Zhu, Xu, and Zhu 2021). Nevertheless, when it comes to unmanned fully autonomous transportation, studies on designing and realizing interfaces with shipping and receiving facilities, are limited and at nascent stage. Working towards addressing this research gap, this study identified challenges and requirements of automated loading and unloading in a setting of autonomous truck freight road transport.

Method
The paper is based on a case study at a production site where autonomous truck transport is currently applied in a pilot setup. In the pilot setup, goods are delivered by an autonomous truck from a production plant to a nearby warehouse, located a few hundred metres from the plant, although travelling partly on a public road. Connected to the pilot setup, preparations are also made for applying automated loading and unloading of the autonomous truck. The study is led by researchers from two universities and is conducted in cooperation with representatives from several companies. All the companies are participating in the preparations for automated loading and unloading at the production site: themanufacturing company operating the production plant and the warehouse, the company providing the autonomous truck, a company providing equipment for automated materials handling, and a company specializing in solutions for load securing. Data is collected through site visits and mapping of processes and material flows, as well as through interviews with the companies involved in the pilot setup and in the preparations for automated loading and unloading.

Analysis and results
The results from the first stage of the project have been used to prepare a base case with a conventional truck and driver used to move pallets between the production plant and the warehouse. A second case uses an autonomous truck to transport the pallets from the production plant to the warehouse. For the base case the truck is loaded by the driver using a forklift truck (FLT) and the driver secures the load. Unloading at the warehouse is done by FLT operated by someone working in receiving area. For the second case (autonomous truck) the vehicle is loaded by FLT operated by someone from the production plant. Unloading is the responsibility of the warehouse receiving the pallets and is therefore the same as the base case operation.Mapping the material flows and the steps involved has shown that the driver plays various roles beyond driving the truck between the plant and the warehouse. These roles include: opening the door/gate at the loading bay, loading the truck with pallets, securing the load, deciding when the truck is full and needs to leave the plant to go to the warehouse and informing the staff at the warehouse that the truck has arrived. After unloading the driver will determine whether the truck should go back to the production plant for another load or should be used for another activity at the production location. When the autonomous truck is used then the ancillary actions carried out by the driver (listed above) have to be done by someone else or a change has to be made to the processes – for example a sensor could indicate the arrival at the warehouse of the loaded truck. Mapping the processes has demonstrated the scale of the challenge in automating these activities and the requirements applying to an automated loading and unloading system. These include the dynamic environment of the loading/unloading area, non-uniformity of goods, scanning of goods (identification tag, ensuring even weight distribution and alignment of pallets, securing of the load). The accountability and responsibilities of different stakeholders in fully automated unmanned system and handling of claims must also be addressed in the change to more automated systems.