Robotic Cleaning of Fish Processing Facilities: Virtual tools, hygienic design and prototyping

Fish and seafood products are among the most valuable resources when considering ways in which to address the need for sustainable food sources in the future. However, any increase in fish processing production must be implemented in an environmentally sustainable way. The cleaning of fish processing plants and equipment the equipment used in such facilities has been identified as an area in which research has the potential to make significant contributions to the reduction of environmental impact, both in terms of the utilization of chemicals during cleaning and the general water consumption that occurs in the processing of fish and the cleaning of fish processing equipment and facilities.
Currently, the most commonly used cleaning practices in the fish processing industry are based on manual operations, which are both subject to human error and unstable. Furthermore, the cleaning of fish processing plants is a demanding manual operation that is characterized by repetitive and stressful tasks. In addition, cleaning fish processing plants is also very costly; however, it is a necessary final step in the daily process of such facilities to ensure food safety. The automatization of such processes has been the go-to approach to solving the challenges faced by such facilities and thus increasing profits in the Norwegian aquaculture industry.
The main objective of this thesis is to determine how fish processing plants may be cleaned more efficiently. The research for this thesis was conducted in the context of an industrial research project intended to develop a robotic cleaning system for fish processing plants. It is predicted that a robotic cleaning system could reduce both the risk of bacterial contamination and costs related to cleaning. Conventional industrial robots have proven to be well-suited to performing repetitive and demanding tasks.
Nonetheless, at the moment, no solution exists for the robotic cleaning of fish processing plants. A major challenge for robots to perform cleaning is conventional industrial robots’ tolerance and ability to adapt to the humid and challenging environments found in fish processing plants, especially during cleaning.
Other challenges arise when considering the commissioning, installation, and industrial performance of complex products such as robotic cleaning systems. Very few new fish processing plants are built each year in Norway; thus, a viable robotic cleaning system concept must be able to be retrofitted into existing plants. Fish processing plants have complex layouts; in addition, spatial information concerning such facilities is often lacking. Furthermore, they run almost continuously. These factors make installation and commissioning time a crucial part of achieving industrial performance and implementation of a robotic cleaning concept.
Developing a robotic cleaning solution requires product development efforts. Product development is important when attempting to obtain competitive advantages, and this research explores how product development is approached in the Norwegian aquaculture industry. In addition, this thesis explores modern virtual prototyping tools and how they can be used to solve some of the challenges related to product development and industrial performance in this industry. Specifically, 3D scanning is proposed as a method for capturing spatial data concerning fish processing plants to aid in the planning and installation of the proposed robotic cleaning system. Furthermore, 3D simulation of robots (e.g. offline programming) provides information about the systems function and performance at early stages of product development and utilized to speed up the product development process and to identify potential errors, improvements and applications with regard to the robotic cleaning system. The project demonstrates that 3D scanning and simulation in combination may well prove key in achieving an acceptable level of industrial performance for a robotic cleaning system.
The results of the research work are two distinct, full-scale robotic cleaning prototypes, which are evaluated by deliberately contaminating fish processing equipment with bacteria, after which the equipment is cleaned. The residual bacterial levels on the equipment are measured to indicate cleaning effectiveness. For the cleaning process, the robotic prototypes are programmed according to best practices in industrial cleaning.
Both tests show that robotic cleaning reduces the bacteria count significantly, and the second prototype cleaning system is found to perform as well as a human operator with 15 years of cleaning experience in fish processing plants.
The first full-scale prototype consisted of a UR10 industrial robot with two auxiliary axes to increase the size of the working envelope. Even though it was found that such a solution is inadequate in terms of reach and functionality, this prototype proved that robotic cleaning is a plausible means of improving cleaning efficiency. The first full-scale prototype provided valuable insights, which enabled the development of a second, more industrialized prototype.
The second prototype robotic cleaning system for fish processing plants was developed and tested in a close-to-real-life lab environment. The system consists of a custom-made linear horizontal rail and trolley, together with a custom-made manipulator specifically designed for the robotic cleaning of fish processing lines. All components are made to withstand the harsh environments in which they will operate, which are characterized by the use of chemicals and high levels of humidity, while also adhering to hygienic design requirements. The design of the system enables the robotic arm to have a long reach while keeping the system’s footprint and weight relatively low when compared to conventional robotic arms. Furthermore, the custom-built robotic cleaning system is designed to be adapted to the various spatial layouts to be found in fish processing plants.
Hygienic design principles were considered during all phases of the product development process to ensure that the robotic cleaning system does not impose any additional threats to food safety in fish processing plants. In addition, hygienic design insights concerning the Norwegian aquaculture industry are evaluated and expanded upon in relation to existing theory regarding hygienic design as well as design for cleaning practices.
It is demonstrated that it is possible to clean fish processing plants through the implementation of robot(s) by utilizing modern virtual prototyping tools and that such an approach is likely to produce results that are equal to or superior to those obtained using traditional cleaning methods. It is also noted that hygienic design plays an important role in enabling robotic cleaning in fish processing plants. Robotic cleaning of fish processing plants has the potential to reduce both production downtime due to cleaning and the need for manual labor, improve the overall hygiene of many processes, and eliminate tasks involving heavy manual workloads.