Bio-inspired robots for confined space industrial applications: a novel cable-driven snake robot design

ScienceDirect Available online at www.sciencedirect.com Procedia CIRP 125 (2024) 107–112 2212-8271 © 2024 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the CIRP BioM 2024 10.1016/j.procir.2024.08.019 Keywords: snake robot; manufacturing; mechatronics. 1. Introduction The integration of automation has led to fundamental improvements in productivity, safety and working conditions in industry [1]. Industrial robots (with rigid links) are known for their repeatability, accuracy, and efficiency, however, mainly dominate in non-complex, predictable environments or predefined tasks. Bio-inspired robots are influenced from biological systems and organisms, to incorporate adaptive and versality behaviors [2]. Unlike traditional robots, they can execute unpredictable tasks in complex environments. Biomimetic robots draw inspiration from nature, therefore creating machines that emulate the shape and locomotion of living beings. Inspired by their progressive adaptation in nature, such robots integrate biological traits that enhance them with kinetic skills and finer control processes than the traditional robots. Insect-like robots are legged robots that can explore complex environments with uneven terrain or obstacles. Hexapods, drawing inspiration from cockroaches have rapid movement and climbing abilities, ant-inspired robots, mimicking the homing behavior of ants, return to their nests after long trips into adverse circumstances [3][4][5], while fleas, are able to perform vertical leaps. [6]. Biomimetic robots also emulate snake-robots, by adopting crawling, climbing [7], or self-supported locomotion [8].Robots’ manipulator also draw inspiration from the living organisms integrating rigid or soft gripping fingers,hand-like grippers, octopus’s tentacle, lamprey’s mouth, or elephant trunk-like grippers [9]. Swarm robots are a field of collective robotics that are inspired from the self-organized behaviors of insects (ants, fish, bees, birds). These animals become more efficient when gathering rather than as individuals. Swarm robotics involves the use of multiple robots to perform tasks collaboratively, rather than increasing the complexity of asingle robot [10]. In this research, we do present the types of robots available and compare some of their characteristics –reachability, CIRP BioM 2024 Bio-inspired robots for confined space industrial applications: a novel cable-driven snake robot design Nikos Dimitropoulosa, Niki Tzirtzilakia, George Michalosa,Sotiris Makrisa,* aLaboratory for Manufacturing Systems & Automation, University of Patras, Rion Patras, 26504, Greece * Corresponding author. Tel.: +30-261-091-0160; fax: +30-261-099-7314. E-mail address: [email protected] Abstract Industrial automation has played a pivotal role towards improvement of productivity, efficiency, working conditions, ergonomics and reduction of health hazards. While a large portion of industrial sectors and processes have or can be automated, certain domains serve as unexplored ground due to the complexity of the processes to be executed, size and material properties of the parts of interest and available space, which highlight the need for new automation technology. In this paper, a systematic classification of product complexity and common industrial processes versus the use of conventional and bio-inspired robots is presented, aiming to identify the benefits of bio-inspired robots over their conventional competitors. Moreover, a novel cable-driven snake robot design is presented, featuring a modular lightweight structure of several segments, each of them controlled by a 3-cable mechanism, providing them 2 degrees of freedom. It exhibits significant potential to demonstrate high levels of versatility in navigating inside intricate, confined environments and narrow passages, such as aircraft fuel tanks, enabling automation of unhealthy processes that traditionally require human intervention. © 2024 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the CIRP BioM 2024 108 Nikos Dimitropoulos et al. / Procedia CIRP 125 (2024) 107–112 navigation flexibility and payload -. Afterwards a systematic analysis is being conducted, linking the most common manufacturing tasks with the appropriate robot type (Section 2). –The systematic analysis refers to the examination of the tasks in manufacturing and the aeronautics sector, the investigation of potential robotized solution systems, their features and their efficiency for each task is evaluated –.Afterwards, a novel snake robot mechanical design is presented (Section 3). The novelty lays in the lightweight and compact actuation mechanism, which uses only 3 motors to actuate all its links. Section 4 showsthe implementation of the design to a physical prototype. The paper concludes with Section 5, discussing the results and outlining future work. Nomenclature 𝑝𝑝ball screw lead [m] 𝑉𝑉 𝑚𝑚𝑚𝑚𝑚𝑚 maximum velocity of the ball screw [m/s] 𝑁𝑁motor velocity [rad/s] 𝑇𝑇torque [Nm] 𝐹𝐹𝑚𝑚𝑚𝑚𝑎𝑎𝑚𝑚𝑎𝑎 axial load [N] 𝜇𝜇𝑚𝑚𝑚𝑚𝑚𝑚 motor efficiency 2. Task complexity vs type of robot Task complexity names the amount of difficulty for the robots to execute the specific assignment. This difficulty could refer to the nature of the task itself, e.g. collaborative, or the skills that the robot should have in order to execute it efficiently, e.g. payload, flexibility, precision, reachability. 2.1. Types of tasks in manufacturing Some of the most common tasks in the manufacturing sector are: parts’ assembly, handling applications in robotics including grasping for manipulation, palletizing, and packaging actions, processing applications such as material removal, milling, drilling, or material adhesion [11] and quality inspection applications confirming that the product complies with the required specifications [12][13] 2.2. Robots in manufacturing Industrial robots depending on their mechanical structure are divided mainly into Cartesian, SCARA, parallel, and articulated robots. Cartesian (or gantry) robots are composed of three prismatic joints in three perpendicular axes.These robots are used in warehouses for grasping and packaging operations[11][13] and for machining tasks [14]. Gantry robots are also used for transporting other robots in automation applications [15].SCARA robots consist of one prismatic and three revolute joints [11].In manufacturing, they usually perform pick and place, assembly tasks and quality inspection tasks of finished products [14]. Parallel robots are mainly made of a closed loop structure of prismatic joints, but they might also have revolute joints. Parallel robots usually perform assembly, high-speed pick-place tasks and material processing applications [11]. Articulated robots consist of rotary joints and links and typically have three to six degrees of freedom. [11] 6DOF robots are used in assembly tasks such as joining, welding, or adhesion operations [16], pick and place tasks, machining processes (drilling, brushing, deburring milling, additive manufacturing)or quality inspection [15]. A collaborative robot (Cobot) is a type of robot designed to work collaboratively with humans, combining human skills with robot’s endurance and strength for improving results. Cobots can be used in pick and place applications, assembly lines [15], polishing, welding, and quality inspection tasks [17]. Mobile robots are high level autonomous robots that can operate either individually or in groups and can relocate themselves and operate in different environments. They can execute material handling, assembly, and inspection tasks while being easily reconfigurable, flexible, and adaptive [18]. Automated guided vehicles navigate in predefined paths by using sensors, mainly performing transportation tasks [19]. 2.3. Bio-inspired robots The purpose of bio-inspired robotics is to mimic the shape, the locomotion, and the behavior of living organisms, with applications in various sectors.In agriculture, soft grippers are used in harvesting applications [20], and robot-bees in pollination [21]. Snake robots that adapt to complex and changeable environments can be used for rescue applications, providing camera viewsin collapsed buildings areas [22], or extinguishing distant sources of fire when equipped. Jumping frog-like [2], crawling octopus-like [23] or insect-like robots [4] can also perform exploration tasks. Nature-inspired grippers are widely used in manufacturing industry. From 2 or 3 finger-grippers to multi-finger grippers, they draw inspiration from the human hand to accomplish tasks of palletizing, grasping, or assembling. For manipulating components of uncertain geometry, or more delicacy, animalinspired grippers can be used (sucking, or soft adaptive grippers, mimicking octopus’s arm, or lamprey’s mouth)[9]. Bio-inspired swarm robotics can be used in manufacturing applications, such as pick-place, packaging, or palletizing tasks. By mimicking the animals’ behaviour and increasing the number of robots that are working together, the task’s cycle time can be decreased [18].Crawling, climbing, or selfsupported animal inspired robots can be used for inspection and maintenance tasks in difficult to access or navigate areas. Table 1 compares and summarizes some key characteristics, namely reachability, navigation flexibility and payload, of each robot type. The score indicates whether the respective criteria are satisfied, as per the analysis of the authors.Regarding reachability, Cartesian robots can perform orthogonal tasks due to their movement in three axes. SCARA robots present more limitations in vertical direction than Cartesians. Delta robots can reach more areas of the tank, while still having restrictions. These three robots have limitations in navigation flexibility and avoiding obstacles due to their limited joints’ movement. Both articulated and snake robots can operate in larger areas but cannot cover the whole tank. However, articulated robots can maneuver slightly better than the previously mentioned robots, but their long links may collide with the obstacles. Wheeled vehicles can reach and navigate inside the tank, assuming an even terrain and the inexistence of narrow areas. Bio-inspired legged robots can climb over obstacles,but may be unstable, Nikos Dimitropoulos et al. / Procedia CIRP 125 (2024) 107–112 109 which give them great reachability but slightly limited flexibility in navigation. Self-supported snake robot present great flexibility and can effectively avoid obstacles. The payload is influenced by the size of the robot. Both Cartesian and SCARA robots should be compact enough to enter the tank thus, their payload is significantly decreased. Bio-inspired legged robots’ stability is affected by the added payload. The snake robots’ payload mainly depends on their mechanical design. Wheeled vehicles can carry a larger size of payload in contrast to legged robots, while parallel robots present variable load capacity. Articulated robots offer high payload capabilities. Table 2 links the most common manufacturing tasks with the appropriate robot type for their execution. Table 1. Comparison of features per robot type (5-completely satisfactory, 4highly satisfactory, 3-significantly satisfactory, 2-partially satisfactory, 1poorly satisfactory, 0-unsatisfactory) Features/ Robot types Reachability Payload Flexibility Cartesian 1 2 0 SCARA 1 3 0 Parallel 2 4 0 Articulated 3 5 1 Wheeled vehicles 4 4 2 Bio-inspired legged robots 5 2 4 Bio-inspired snake robots 3 2 5 Table 2. Tasks in manufacturing vs robot type. Type of task Proposed robot Pick and place in production line Parallel robot Heavy-duty pick and place Articulated robot Assistance in assembly process Collaborative robot Transportation of finished products Mobile robot Grasping different shaped products Robot with bio-inspired soft gripper Confined spaces inspection Bio-inspires snake robot Pipes inspection Bio-inspired crawling robot Inspection through narrow gaps Bio-inspired insect-like robot 2.4. Snake robots –valuable tool for the aeronautics sector In the aeronautics sector, inspection and maintenance tasks are carried out on a regular basis, to ensure proper working of the aircraft. One of the most challenging areas to be inspected are the fuel tanks[8]. Visual inspections typically involve checking for cracks, corrosion, sealant absence, loose fuel lines, or foreign objects existence and are mainly performed manually with the use of special equipment.Although the tanks are ventilated prior to human’s entrance, the environment remains hazardous for them, especially when they stay inside for a long period of time. A remote and automated inspection of the fuel tanks would decrease the exposure of humans to dangerous environments and the inspection cycle time. However, a robotized inspection presents challenges due to the complex environment of the fuel tanks. The confined tanks are often equipped with multiple obstacles, such as tubing, making the navigation of a conventional robot almost impossible. Unlike those robots, snake robots pose the benefits of a more flexible, thinner structure, which can navigate inside the tight tank, and avoid barriers, to perform the required visual inspection tasks. Snake-like systems can be divided into structures with a continuous-flexible backbone or a rigid backbone (combination of rigid segments and flexible joints). Niu G [8] developed a single joint continuum robot of 8 sections with Rzeppa universal jointsactuated by 3 cables and stepper motors. Gao Q. J. [24] developed a prototype continuum robot with 3 sections using a flexible glass fiber elastic rod backbone actuated by 4 cables per section and 6 DC motors in total. Dong X. [25] constructed a slender continuum robot with 12 sections of 2DOF each and 1DOF for coiling, actuated by 2 pairs of cables (twin compliant joint) and 26 motors in total. Wang M. [26] developed a structure with 10 sections of 1DOF (continuous elastic NiTi rods and 1 pair of cables) and 3 sections of 2DOF (short NiTi rods with 3 cables), actuated by 29 motors. He J. [27] developed a snake arm with 3 sections of 2DOF (using ball joints)and 9 motors. Tang L. [28] developed a snake robot with 12 sections of 24DOF and 36 motors in total. All the above designs use multiple motors for the actuation of the arm, which leads to a large volume of their actuation system. A minimized footprint of the actuation system would give the robotic system more flexibility as it could enter inside the fuel tank while navigating. The proposed cable driven robot uses only three motors for its actuation, and their configuration results in a more compact volume of its footprint. Therefore, it can enter the confined wing tanks through their access opening. Furthermore, the current implementation presents more degrees of freedom compared to some existing solutions. 3. Cable-driven snake robot design architecture A 10DOF cable-driven snake robot is designed to navigate inside the confined environment of fuel tanks with dimensions 4 m * 0.6 m (length * width), fit their 0.254 m *0.457 m access hole and avoid the obstacles (pipes) inside. The proposed robot consists of arobotic arm and a transmission system. 3.1. Snake arm The design procedure of the proposed robot included workspace, and flexibility analysis of different concepts. The workspace analysis concerned a virtual wing tank environment creation with multiple pipes as obstacles and an access hole. Afterwards, the number of joints–and therefore the degrees of freedom–were determined. While an increased number of joints would enhance the system’s flexibility, they would also enhance the actuation system’s complexity and volume. The designed implemented accommodates 10DOF divided into 5 sections (Fig. 1). The number of sections was selected to maintain robot’s footprint compact, thus enabling a complete entry inside the wing tank, while satisfying the maneuverability requirements. Additional sections would require more wires for manipulation, thus more and longer transmission modules and a bigger volume of the actuation system. The goal of the arm’s maximum length was set 1.3 m, given that the robot can enter completely inside the tank, thus enhancing its reachability. Flexibility analyses were also performed, in which the robot movement was simulated inside the virtual environment, to evaluate its ability to avoid obstacles, maneuverable around them and perform inspection tasks both along the length and 110 Nikos Dimitropoulos et al. / Procedia CIRP 125 (2024) 107–112 width of the tank. Those analyses indicated that using sections of two different lengths could increase flexibility, compared to using same length sections. The two sections closer to the base are selected to be 0.230 mlong, for rougher movement of the robot, whereas the last three sections are selected to be 0.095 mlong each for a more delicate one. This configuration improves the precision of the robot’s end-effector movement, thus enabling it to navigate between obstacles. These length configurations led to 1.290m reachability, close to the set goal. The snake robot’s main dimensions are reported in Table 3. Fig. 1. Proposed cable-driven snake robot. Table 3. Cable-driven cable robot dimensions. Description Dimensions Overall length 1.970 m Arm length 1.290 m Arm diameter (sections 1-5) 0.80 m Base dimensions (width*height) 0.281 m *0.167 m Payload 3 kg Each section consists of a Cardan joint, two disks and a link. The two disks are connected to the link and equipped with openings to accommodate the wires’ passage through them. The openings are designed in a way that the wires do not conflict even in the 1st section where they are not in order (Fig. 2) The cardan joint is attached to the lower disk and the previous section respectively. Fig. 215 cables accommodation in 1st section. Fig. 3 4th - 5th section's main components. The 2DOF movement for every section is achieved by the associated Cardan joint. All individual sections of the arm can rotate in two directions up to 1.047 rad. The robotic arm results from the integration of all the corresponding sections. Three wire ropes, 0.002 m diameter each, uniformly distributed at 2.094 rad, are used to execute the 2DOF motion of the cardan joint within each section. The main section’s components and wires’ configuration are presented in Fig. 3. 3.2. Transmission system Each rope leads to robot’s base, at the motion transmission module, for actuation. Various concepts were examined, such as drums and attached motors that wrap and unwrap ropes. This would decrease overall length, however, increase complexity; drums designed with grooves to properly house the wires and pulleys for their guidance. Another concept examined was a ball screw assembly with linear rails for wires movement, but this would enhance the volume and weight, compared to shafts. Each transmission module of the proposed solution consists of a ball screw, a ball screw nut, ahollow aluminum slide shaft, a motion bearing, a coupler, a shaft bearing, two shaft supports and a wire connector unit. Ball screws provide precision and low backlash (0.000 002 m to 0.000 05 m[29]) essential for accuracy. They enable secure and easy integration, compared to pulley configurations, that might present wire slippage. The ball screws’ lead is calculated to be at least 0.005 m by Eq. 1. 𝑝𝑝 = 𝑉𝑉 𝑚𝑚𝑚𝑚𝑚𝑚 ∗ 2 ∗ 𝑝𝑝𝑝𝑝 𝑁𝑁 (1) A lightweight construction is achieved by a hollow slide shaft and wire rope fixturescrafted by PVC material. In total, 15 transmission units of varying lengthshave been constructed and assembled to ensure tight packaging and a compact footprint of the snake base. The transmission modules are connected to the actuation system. Upon energization, they obtain linear motion and modify the length of the wires, hence accomplishing the motion of the robotic arm. The wire ropes remain constantly under tension and can be coated with PTFE to minimize friction during movement. A novel actuation system design has been implemented, resulting in a significant reduction of the number of motors required to actuate the entire robot. The novelty stands that 3 stepper motors actuate all 15 wire ropes, with each motor responsible for actuating a group of 5wires, respectively with the use of electromagnetic clutches.The engagement or disengagement of the clutches gives or stop motion to the respective wires of the different groups. The 3 respective groups are demonstrated in Fig. 4. Stepper motors can provide precise positioning at low speed and are less expensive than other types of motors, factors essential for this application. The torque required to drive the ball screw is calculated by Eq. 2. 𝑇𝑇 = 𝐹𝐹𝑚𝑚𝑚𝑚𝑎𝑎𝑚𝑚𝑎𝑎 ∗ 𝑝𝑝 2 ∗ 𝑝𝑝𝑝𝑝 ∗ 𝜇𝜇𝑚𝑚𝑚𝑚𝑚𝑚 (2) The axial load is calculated in a worst-case scenario of the wires’ tension: arm into full extended horizontal position or rotate. Each wire is responsible for the load of the corresponding section adding an efficient factor 75% for frictional forces. The assumptions made for a static scenario were non-extensible wires, without mass and aluminum snake arm under 3 kg payload.The estimated tension for the 1st and 2nd sections is 72 N, for the 3rd and 4th 24 N and for the 5th 161 Nikos Dimitropoulos et al. / Procedia CIRP 125 (2024) 107–112 111 N. Motor efficiency is assumed 80%. The required driving torque is calculated for all individual transmission modules. At total, three Nema23 stepper motors [30] of 3 Nm are selected. Fig. 4. Transmission groups: a) 1st group; b) 2nd group; c) 3rd group. The power transmission to groups is executed with a timing belt and a system of pulleys. Idler pulleys are integrated to keep the timing belt in tension and help with its teeth engagement to the pulleys. The above-mentioned configuration is illustrated in Fig. 5 for the 2nd and 3rd transmission groups. Fig. 5. Components configuration for power transmission. An electromagnetic clutch is used for each transmission module, which enables the motion transmission from the motor, adjusting the wire’s length. When the desired position is reached,the clutch disengages, and an electromagnetic brake is powered on to maintain the wire’s position. Fig. 6 indicates the snake robot’s actuation configuration, including the motion and power transmission assemblies. Clutches and brakes 0.6 Nm torque were selected for sections 1-4, whereas 5th section uses 1.2 Nm torque. The integration of an actuation system including 3 motors, electromagnetic clutches, and brakes, instead of the use of fifteen individual-appropriately sizedmotors for controlling each wire, decreased overall weight by 4.4%(2.6 kg and 2.72 kg [31] respectively). 4. Prototype A physical prototype is developed to verify the real-world applicability of the design and drive the future developments. The sections’ disks and the link were 3d printed (ePLA-Matte material [32] –the disks were printed with 6 wall lines and 20% grid infill density and the links with 2 wall lines) and attached to each other using threaded rods. The 3d printed material (0.848 kg) decreased the overall weight by 77.2%, compared to using aluminum (3.719 kg). Some modifications were also made in the prototype’s transmission modules compared to the initial design; lead screws were used as a substitute of ball screws. Although lead screws might not provide the same precision as ball screws, they are self-locking and ensure a lowcost integration. All mounting plates were manufactured by PVC material and are connected to each other with aluminum profiles. Fig. 7 illustrates the robot’s actuation system and mounting structure and Fig. 8 indicates the complete prototype. Fig. 6Cable-driven robot actuation system. Fig. 7. Transmission system of snake robot prototype. Fig. 8. Cable-driven snake robot prototype. At this stage, the robot was not electrically actuated. The goal of the prototype was to validate the feasibility of the tight, in terms of space, assembly, the clearance of the substantial components, the flexibility and mobility of the snake robot. Therefore, the structural rigidity of the arm’s components, their stiffness and the wires’ friction were not considered further than the efficiency factor that added in their tension calculation, at this phase of the development. PVC was selected as a lightweight and low-cost material. When the snake robot design is optimized and actuated, aluminum material can be used as an alternative. Milled aluminum plates would enhance a more compact assembly of the actuation parts. 5. Results The proposed cable-driven snake robot design uses only one motor for the actuation of 5 wires resulting to a significant reduction of the number of motors, unlike existing solutions that require one motor for the actuation of a single wire. This leads to acompact footprint, allowing the robot to enter completely inside wing tanksthrough their access holes, unlike existing solutions that have larger footprints, and remain outside the tank during tasks. The prototype’s weight was measured ~9.7 kg, which enables its integration to a medium payload articulated robot as its end-effector. While the 112 Nikos Dimitropoulos et al. / Procedia CIRP 125 (2024) 107–112 proposed design presents fewer DOF and limited reachability than some solutions of the literature, its ability to fully enter inside the tank and its potential integration with other articulated robots, can enhance its working envelope for the inspection tasks execution. This capability enhances the proposed solution’s versality and efficiency by overcoming any limitations in DOF or reach in contrast to other solutions. 6. Conclusions –future work Summarizing, this paper compares bio-inspired and traditional robots regarding their features (reachability and flexibility) and their applicability in manufacturing tasks. Furthermore, a 10DOF novel cable-driven snake robot is proposed, which can perform inspection tasks inside confined environments. The novelty lays in its actuation system, consisting of only 3 motors combined with electromechanical clutches and brakes. This offers a compact robot footprint which can be mounted directly on medium payload robots. Despite its flexibility, the cable-driven robot provides uncomplicated maintenance of all constituent components, in case of part failure. Future steps will focus on the enhancement and finalization of the prototype by developing and integrating the electronics and control system. Simultaneously with activation, friction forces, programming, trajectory smoothness, or components’ wear will be evaluated. The robot will be examined for its mobility in multiple poses, maneuverability and efficiency in navigating and avoiding obstacles, while performing inspection tasks inside a wing tank replica environment. Furthermore, the precision of the cable-driven mechanism will be evaluated. Acknowledgements This research has been supported by the EU project “CONVERGING Social industrial collaborative environments integrating AI, Big Data and Robotics for smart manufacturing”. This project has received funding from the European Union’s Horizon Europe research and innovation programme under grant agreement No 101058521. References [1] Chryssolouris G. Manufacturing systems: theory and practice. Springer Science & Business Media 2013. [2] Gao Z., Shi Q., Fukuda T., Li C., Huang Q. An overview of biomimetic robots with animal behaviors. Neurocomputing 2019; 332: 339-350. [3] Manoonpong P., Patanè L., Xiong X., Brodoline I., Dupeyroux J., Viollet S.,..., Serres J. R. Insect-inspired robots: bridging biological and artificial systems. Sensors 2021;21.22:7609. [4] Dupeyroux J., Serres J. R., Viollet S. AntBot: A six-legged walking robot able to home like desert ants in outdoor environments. Science Robotics 2019;4.27:eaau0307. [5] Delcomyn F., Nelson M. E. Architectures for a biomimetic hexapod robot. Robotics and Autonomous Systems 2000;30.1-2:5-15. [6] Noh M., Kim S. W., An S., Koh J. S., Cho K. J. Flea-inspired catapult mechanism for miniature jumping robots. IEEE transactions on robotics 2012;28.5:1007-1018. [7] Wright C, Johnson A, Peck A, McCord Z, Naaktgeboren A, Gianfortoni P Choset H. Design of a modular snake robot. IEEE/RSJ International Conference on Intelligent Robots and Systems. IEEE 2007; p. 2609-2614. [8] Niu G., Wang J., Xu K. Model analysis for a continuum aircraft fuel tank inspection robot based on the Rzeppa universal joint. Advances in Mechanical Engineering 2018;10.5:1-10. [9] Nguyen V. P., Dhyan S. B., Mai V., Han B. S., Chow W. T. Bioinspiration and Biomimetic Art in Robotic Grippers. Micromachines 2023;14.9:1772. [10] Brambilla M., Ferrante E., Birattari M., Dorigo M. Swarm robotics: a review from the swarm engineering perspective. Swarm Intelligence 2013;7:1-41. [11] Siciliano B., Khatib O., Kröger T. Springer handbook of robotics. 2nd ed. Berlin: springer 2008. [12] Kurniati N., Yeh R. H., Lin J. J. Quality inspection and maintenance: the framework of interaction. Procedia manufacturing 2015;4:244-251. [13] Bekey G. A. Biologically inspired control of autonomous robots. Robotics and Autonomous Systems 1996;18.1-2:21-31. [14] Anbarasi M., VG D. K., Ilavazhagan M. Warehouse Handling utilizing Cartesian Robots 2019. [15] Andronas D., Argyrou A., Fourtakas K., Paraskevopoulos P., Makris S. Design of human robot collaboration workstations–two automotive case studies. Procedia Manufacturing 2020;52:283-288. [16] Makris S., Alexopoulos K., Michalos G., Sardelis A. An Agent-Based System for Automated Configuration and Coordination of Robotic Operations in Real Time—A Case Study on a Car Floor Welding Process. Journal of Manufacturing and Materials Processing 2020;4.3:95. [17] Zacharaki N., Dimitropoulos N., Makris S. Challenges in human-robot collaborative assembly in shipbuilding and ship maintenance, repair and conversion (SMRC) industry. Procedia CIRP 2022;106:120-125. [18] Michalos G., Kousi N., Makris S., Chryssolouris G. Performance assessment of production systems with mobile robots. Procedia CIRP 2016;41:195-200. [19] Moshayedi A. J., Jinsong L., Liao L. AGV (automated guided vehicle) robot: Mission and obstacles in design and performance. Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering 2019;12.4:5-18. [20] Navas E., Fernández R., Sepúlveda D., Armada M., Gonzalez-de-Santos P. Soft gripper for robotic harvesting in precision agriculture applications. In: International Conference on Autonomous Robot Systems and Competitions (ICARSC). IEEE 2021; p. 167-172. [21] Perez-Uribe A., Hirsbrunner B. Learning and foraging in robot-bees. CEC2000 2000. [22] Whitman J., Zevallos N., Travers M., Choset H. Snake robot urban search after the 2017 mexico city earthquake. In: International symposium on safety, security, and rescue robotics (SSRR) IEEE 2018; p. 1-6. [23] Calisti M. Soft robotics in underwater legged locomotion: From octopus– inspired solutions to running robots. In: Soft Robotics: Trends, Applications and Challenges: Proceedings of the Soft Robotics Week, April 25-30, 2016, Italy. Springer International Publishing 2017; p.31-36. [24] Gao, Q. J., Wang W. J., & Niu G. C. Design bionic structure and analysis of kinematics for aircraft fuel tank inspection robot. Applied Mechanics and Materials 2013, 278: 594-598. [25] Dong X., Axinte D., Palmer D., Cobo, S., Raffles M., Rabani A., Kell J. Development of a slender continuum robotic system for on-wing inspection/repair of gas turbine engines. Robotics and computer-integrated manufacturing 2017, 44: 218-229. [26] Wang M., Palmer D., Dong X., Alatorre D., Axinte D., Norton A. Design and development of a slender dual-structure continuum robot for in-situ aeroengine repair. IEEE/RSJ International Conference on Intelligent Robots and Systems 2018. IEEE.ISO 690: 5648-5653. [27] He J., Liu R., Wang K., Shen H. The mechanical design of snake-arm robot. In IEEE 10th International Conference on Industrial Informatics 2012, 758761. [28] Tang L., Wang J., Zheng Y., Gu G., Zhu L., Zhu X (2017). Design of a cabledriven hyper-redundant robot with experimental validation. International Journal of Advanced Robotic Systems 2017:14.5:1729881417734458. [29] TPA Motion LLC, Ball Screw Technical Description, www.tpamotion.com/assets/pdata/kss/ballscrew-technical-data.pdf [30] Nema23 Closed Loop Stepper Motor, https://www.omcstepperonline.com/index.php?route=product/product/get_file&file=1553/23 HS45-4204-ME1K_Full_Datasheet.pdf, last accessed in 20.02.24 [31] Closed Loop Stepper Motor, https://www.omc-stepperonline.com/closedloop-stepper-motor, last accessed on 20.02.24 [32] ePLA, www.esun3d.com/epla-matte-product, last accessed on 20.02.