Browsing by Author "Dassanayake, PC"

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    item: Conference-Full-text
    Design and development of a soft gripper system for difficult-to-handle food items
    (IEEE, 2023-12-09) Hashanjana, L; Senanayaka, P; Madushan, I; Himaruwan, HDS; Kulasekera, AL; Dassanayake, PC; Abeysooriya, R; Adikariwattage, V; Hemachandra, K
    There are many food products or handling operations, such as grasping food materials with less thickness and extremely delicate, which cannot be performed using existing soft grippers. As a result, these operations are eventually left for human laborers to perform. In this paper, we present a novel soft gripper that takes advantage of the integration of a soft gripper mechanism with higher holding force and reconfigurable plate to grasp especially fewer thickness foods. There is a mechanism to adjust the gripper arms which can be performed inside a higher reconfigurable working area. This gripper can grip less thick and delicate foods compared to conventional grippers while maintaining a higher grasping success rate. A prototype of the gripper was evaluated in an experimental setup, where real ingredients were used. The gripper demonstrated versatile grasping capabilities, allowing for a wide range of foods to be handled effectively. A maximum bending angle of the gripper 41°was obtained without load for the applied pressure values. The gripper exhibited a maximum pulling force of 18.2 N at a 40 kPa (abs) pressure. These innovative concepts suggest that this approach to food handling holds a significant contribution to delicate food handling in automated food production.
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    item: Conference-Extended-Abstract
    Experimental bending performance characterization of sHAMs used underwater growing robot
    (Engineering Research Unit, 2023-12) Malinda, HAN; Marasingha, MMTM; Senarath, SCD; Dassanayake, PC; Kulasekara, AL
    Soft-growing robots represent an emerging field characterized by their ability to extend at the tip while the base remains stationary. These robots offer a unique advantage in navigating through confined spaces inaccessible to humans. Specifically, in underwater exploration tasks, their flexible bodies render them particularly efficient. Moreover, these robots exhibit the capability to steer even while growing. There exist several steering methods including sHAMs (soft Hydraulic Artificial Muscles), sPAMs (soft Pneumatic Artificial Muscles), tendon-driven techniques, and predefined bending mechanisms, applicable both in air and underwater [1],[2]. This paper specifically delves into the study of sHAMs (soft Hydraulic Artificial Muscles) and their inherent characteristics. Various critical factors influence the bending behavior of sHAMs, including pressure, the diameter ratio between the robot body and the sHAM, the length of the robot body, and the number of sHAMs employed. In this study, we concentrate on varying the diameter ratio between the body and sHAM, while keeping other parameters constant. To achieve this, we fabricated robot bodies with varying diameters while maintaining a constant diameter for the sHAM. By systematically analyzing the results obtained from this experimental setup, we aim to provide insights into how the bending angle varies in relation to the diameter ratio.
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    item: Conference-Full-text
    Experimental evaluation of steering actuator configuration on the behaviour of a soft growing robot
    (IEEE, 2022-07) Premarathna, MM; Weerasinghe, RK; Peiris, NN; Kulasekera, AL; Dassanayake, PC; Rathnayake, M; Adhikariwatte, V; Hemachandra, K
    Soft growing robots are a novel concept that uses fluid flow to increase in length at the tip. Using effective steering mechanisms, soft-growing robots can grow along the desired path. Series pneumatic artificial muscles (sPAMs) are used as steering actuators in contemporary soft-growing robots. This paper presents the experimental evaluation of the effect of the sPAM configuration on the bending of a soft-growing robot. The paper also includes the design and fabrication of the robot body and the sPAMs, the experimental setup, and the analysis of the observed results. The soft-growing robot body and sPAMs are made of low-density polyethylene (LDPE). The effect of four sPAM configurations (n sPAMs in m groups) on the bending angle and the blocked force is experimentally evaluated. Experimental results show that the bending angle is proportional to the number of sPAMs in a group (Bending angle reduces from 33° to 12° as the number of sPAMs in the group is reduced from 6 to 2). The blocked force applied by the robot tip remains constant over all the tested sPAM configurations. Hence, by varying sPAM configurations, a designer will be able to change the bending angle of a soft-growing robot without affecting tip forces.
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    item: Conference-Full-text
    Experimental performance characterization of an underwater growing robot
    (IEEE, 2023-12-09) Tennakoon, KE; Subasingha, GS; Sewwandhi, JA; Kulasekera, AL; Dassanayake, PC; Abeysooriya, R; Adikariwattage, V; Hemachandra, K
    Soft-growing robots are an emerging field of robots that perform their growth through tip extension using a fluid flow-driven system while the robot base is stationary. With growth without relative motion with the surrounding, this can be applicable in areas of exploring constrained environments where minimum harm to the environment is required. This paper presents an experimental performance characterization of a soft underwater growing robot designed for exploring shallow water coral reef environments. The robot’s design, fabrication, and control are described, emphasizing the integration of the robot base, retraction setup, and robot body. The experiments evaluate growth velocity and tip force under various depths and flow rates. Results show consistent tip velocity across depths, with a slightly higher velocity of 14.2 mm/s at approximately 330 mm depth. The tip velocity increases with the flow rate but at a decreasing rate. The average tip force per unit length decreases with greater depth, exhibiting a nearly linear distribution from 533 mm to around 203 mm. Depths below 203 mm result in significantly higher tip forces. Through these findings, the research provides information on robot performance and advances the realization of the concept in sensitive underwater environments