Browsing by Author "Gopura, RARC"

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item: Conference-Abstract
A 3DOF transtibial robotic prosthetic limb
Madusanka, DGK; Wijayasingha, LNS; Sanjeevan, K; Ahamed, MAR; Edirisooriya, JCW; Gopura, RARC
A robotic prosthesis is a device which is used to replace a missing body part. These devices are intended to return the amputees to their pre-amputation functional status. Below knee (Transtibial) amputation is the most common amputation occurred in the lower limb. That is caused by reasons such as diseases, injury due to explosions of anti-personnel land mines and accidents. The existing prostheses for transtibial amputees have yet to be improved to reinstate the biomechanical functions normally provided by the ankle joint. Therefore, the purpose of this research is to develop a transtibial robotic prosthesis which would provide functions usually provided by the ankle. The proposed design consists of 3 Degrees of Freedom (DOF) to generate similar biomechanical motions at the ankle joint. Further it includes a passive regenerative system to reduce motor power requirement of dorsiflexion/plantarflexion. Experiments are carried out to verify the effectiveness of the proposed prosthetic limb and to verify the possibility of using electromyographic (EMG) signal based control of the prosthesis.
item: Conference-Abstract
A Review on Multi‐Agent systems in micro grid applications
Kulasekera, AL; Gopura, RARC; Hemapala, KTMU; Perera, N
The applications of Multi-Agent Systems (MAS) in electrical power systems are becoming popular due to their inherent benefits such as increased autonomy, reactivity, pro activity and social ability. This paper reviews current research on the application of multi-agent systems in micro grid schemes. The paper is mainly focused on recent developments of multi-agent systems in different aspects of micro grids such as control, market modeling, optimization and power restoration. The future directions of multi-agent systems in micro grid applications are also discussed briefly. Furthermore, this review is concluded by discussing the development of an enhanced multi-agent based distributed control framework for micro grids.
item: Thesis-Abstract
Analaysis and simulation of a poly bag manufacturing systems
Gopura, RARC; Jayawardene, TSS
The film blowing plays a major role in manufacturing poly bag products that are indispensable in day-to-day life. Film blowing is largely deployed to manufacture poly bags in a continuous flow. As material prices skyrocket to new heights and forecasters see no end to this trend, any positive contribution in the poly bag manufacturing value chain has a great impact on reducing the manufacturing costs. High density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and polypropylene (PP) are basically used as raw materials for the poly bag manufacturing and subsequently undergo some other processes such as cutting, sealing, printing, quality checking, and packing. Due to the variations of parameters in poly bag manufacturing process with different products, a considerable setting time as conceded and substantial amount of raw material is wasted. Material wastage is high as 10% to 12% in figures. Rather high lead-time, improper line balancing, and improper inventory control mimic serious bottlenecks in the system from performance point of view. With the purpose of identifying the productivity and the efficiency problems of the poly bag manufacturing system, as a preliminary study to simulation, risk analysis, bottle neck analysis, and SWOT analysis were carried out in poly bag manufacturing system. Then the possible risk of the selected system was prioritized. In addition, a computer based simulation has been carried out to simulate the system and thereby find the draw backs. The poly bag manufacturing system has been modelled to obtain the optimum production times and throughput time of a given type of bag. Production schedule has been developed for maximum productivity by using the simulated production and throughput times, and customer orders. The effect of changing the parameters of the control process was investigated through simulation trials. A Graphical User Interface (GUI) was developed to present the result of simulation easily and user friendly.
item: Conference-Abstract
Analysis of risks and bottlenecks of a poly bag manufacturing factory - a case study
(2008) Gopura, RARC; Jayawardene, TSS
The material prices of poly bags skyrocket to new heights and forecasters see no end to this trend. Also legal restrictions are imposed on some types of polythene products. In this situation, any entrepreneur engaging in the poly bag manufacturing process faces significant challenges. Therefore, a case study of an analysis of risks and bottlenecks of a poly bag manufacturing factory was carried out for the purpose of modeling and simulation of a poly bag manufacturing factory to improve the productivity to face the underlying challenges. This paper presents the analysis methods, and the results of the analysis are also discussed.
item: Article-Abstract
Analysis, modeling and simulation of a poly-bag manufacturing system
(2016-09-22) Gopura, RARC; Jayawardane, TSS
The cost of raw material of poly-bags increases and fluctuates with an unpredictable trend. Further, legal restrictions imposed on some types of polythene products adversely affects for the demand. In this context, entrepreneurs engaging in poly-bag anufacturing face major challenges. With the purview of optimizing the poly-bag manufacturing process, authors attempted to analyze, model and simulate the poly-bag manufacturing process in the light of posed challenges. This paper presents preliminary analysis, modeling and simulation strategies of a poly-bag manufacturing system. In addition, a risk prioritization method is proposed in the preliminary analysis and also a simulation tool is developed.
item: Conference-Full-text
Assessment of elbow rehabilitation using single dof robotic exoskeleton
(IEEE, 2023-12-09) Cooray, TMGCSP; Gopura, RARC; Abeysooriya, R; Adikariwattage, V; Hemachandra, K
Stroke is a leading cause of permanent disability or inconvenient movements among adults worldwide. Due to strokes, the ability to make quality movements has been reduced. Researchers have introduced rehabilitation processes to restore the quality of movement and improve the quality of life of patients. To assist and evaluate stroke patients, robotic devices have been introduced. These devices can improve the effectiveness of the process and reduce time. This research proposes a robotic system that can perform stroke evaluation and support the rehabilitation process. This research is divided into three stages. In the first stage, the torque of the patient’s elbow joint was calculated using the kinematics of the system and the dynamic model of the arm. The torque estimation model has three main functions: inertia parameters were calculated using research, motor torque was computed using motor current, and kinematics data were captured using IMU (Inertia Motion Unit) sensors. In the second stage, muscle activation was calculated using an optimization algorithm. An optimization algorithm was developed using the musculoskeletal properties of the human arm and hill-type muscle models. Muscle activation based on the optimization algorithm is compared with EMG to identify the correlation of the data. In the third stage, a quantitative assessment of spasticity was performed using the Tonic Stretch Reflex Threshold (TSRT) estimation. Experiments were carried out in healthy subjects with voluntary participation. TSRT and biomechanical measurements are used to classify stroke patients. The estimated muscle activation was validated using captured EMG signal profiles.
item: Conference-Abstract
A Brief review on upper extremity robotic exoskeleton systems
(2016-09-23) Gopura, RARC; Kiguchi, K; Bandara, DSV
Robotic exoskeleton systems are one of the highly active areas in recent robotic research. These systems have been developed significantly to be used for the human power augmentation, robotic rehabilitation, human power assist, and haptic interaction in virtual reality. Unlike the robots used in industry, the robotic exoskeleton systems should be designed with special consideration since they directly interact with human user. In the mechanical design of these systems, movable ranges, safety, comfort wearing, low inertia, and adaptability should be especially considered. Controllability, responsiveness, flexible and smooth motion generation, and safety should especially be considered in the controllers of exoskeleton systems. Furthermore, the controller should generate the motions in accordance with the human motion intention. This paper briefly reviews the upper extremity robotic exoskeleton systems. In the short review, it is focused to identify the brief history, basic concept, challenges, and future development of the robotic exoskeleton systems. Furthermore, key technologies of upper extremity exoskeleton systems are reviewed by taking state-of-the-art robot as examples.
item: Conference-Full-text
C-jae: 3 dof robotic ankle exoskeleton with compatible joint axes
(IEEE, 2018-05) Weerasingha, AH; Pragnathilaka, ADKH; Withanage, WPK; Ranaweera, RKPS; Gopura, RARC; Chathuranga, D
This paper proposes a three degrees of freedom (DOF) robotic ankle exoskeleton with compatible joint axes, named C-JAE. The device consists of three separate units to achieve triplanar motions. The plantarflexion-dorsiflexion and inversion-eversion are externally powered, whereas internalexternal rotation is passively supported. C-JAE is capable of complying with the functional and ergonomic requirements of the biological ankle joint. This is achieved by accurately mapping exoskeleton axes of rotation with the oblique axes of rotation of talocrural and subtalar joints of ankle. All mechanisms including the drive units are located anterior to shank and foot segments to carry out robotic rehabilitation and/or to provide locomotion assistance for humans having mobility disorders. Control experiments were conducted to assess aptitude of C-JAE to carry out ankle rehabilitation exercises. The results verified potential benefits of the proposed design to generate desired movement patterns of daily activities while providing power-assistance.
item: Conference-Abstract
Control methodologies for upper limb exoskeleton robots
(2016-09-22) Gunasekara, JMP; Gopura, RARC; Jayawardane, TSS; Lalitharathne, SWHMTD
An exoskeleton robot is kind of a man-machine system which mostly uses combination of human intelligence and machine power. These robotic systems are used for different applications such as rehabilitation, human power amplification, motion assistance, virtual reality etc. Successful operation of an exoskeleton robot depends on correct selection of design and control methodologies. This paper reviews control methodologies used in upper limb exoskeleton robots. In the review, the control methods used in the exoskeleton robots are classified into three categories: control system based on human biological signal, non-biological signal and platform independent control system. Different types of control methods under each category are compared and reviewed.
item: Conference-Extended-Abstract
Design of a low cost hand operated yarn trimming device for conventional lock stitch machines
(2007) Gopura, RARC; Attanayake, N; Arumapperuma, C; Aravinthan, V
Yarn trimming is' carried out by using a pair of scissors in conventional lock stitch machines. Three steps should be followed to trim the yarn. First, the presser foot is lifted by using the knee lifter (hand lifter in some household old lock stitch machines). Then the fabric is moved out and ultimately the yarn is trimmed using a pair of scissors. When the pair of scissor is used, it should be taken to hand and then trimming is done, which is a time consuming task.
item: Conference-Full-text
Design of a weft gripper system for required weft tension on rapier loom
(2006) Gopura, RARC; Gunasekara, JMP; Fernando, EASK
In an existing rapier loom, when the rapier comes out from the shed, the tension of the weft yam changes before the reed reaches the fabric fell. Also in case of elastic yam, a certain length of the yam may retract due to the elastic nature of the yam. With the existing systems of rapier looms, weft yam tension cannot be controlled until the weft is interlaced into the fabric. Because of the above reasons the quality, selvage and appearance of the fabric could be impaired.
item: Conference-Abstract
Design of an ergonomically efficient chair
(2008) Gopura, RARC; Amarasena, KGAH
Ergonomically designed chairs are important for long time seated workers to increase their productivity and also to reduce low back injuries due to use of poorly designed chairs in ergonomic aspects. In addition, ergonomically designed chairs increase the seating comfortability of the chair users. Most of the chairs designed for the long time seated workers are not considered the full ergonomic aspects. In this paper, we discuss a design of an ergonomically efficient chair for the long time seated workers to increase their productivity and also to reduce low back injuries.
item: Conference-Abstract
Detection of air leakage at the skin – edge of the mask surface with the component of automation in bag valve mask
(Faculty of Medicine, University of Moratuwa, 2024) Kiriharan, K; Kanuwana, KPMC; Kariyapperuma, PW; Kaviraja, GKMRS; Kumarasiri, HKST; Gopura, RARC; Peries, WANN; Kottahachhi, J; Peries, WANN; Talagala, I; Samarasinghe, T; Fernando, NS; Pasqual, D; Chandran, T; Shajahan, Z
The study focuses on improving manual resuscitation bag valve masks (BVM) used in emergencies. Manual BVMs require skilled operation and face challenges like inconsistent ventilation and air leakage. The proposed solution is an automated BVM with air leakage detection at the mask's skin-edge surface. The research aim is the development of a bag valve mask that provides adequate ventilatory support during CPR with minimal air leakage via skin-edge of the mask surface.
item: Conference-Abstract
Developing a learning platform for medical professionals and students to optimize the dissemination of latest medical knowledge
(Faculty of Medicine, University of Moratuwa, 2024) Illankoon, IMDN; Imesha, LGP; Jayasekara, EJKPKV; Jayasekara, MKGKU; Jayasinghe, DGAC; Gopura, RARC; Peries, WANN
In today's healthcare landscape, accessing up-to-date medical knowledge is crucial for professionals. However, existing learning platforms in Sri Lanka often do not meet their specific needs, limiting effectiveness. This research aims to create a specialized learning platform tailored for Sri Lankan medical professionals and students. The project focuses on designing user-friendly, interactive tools that accommodate busy schedules and diverse learning preferences, ultimately enhancing professional development and patient care outcomes in the region.
item:
Development of a 2DOF lower extremity exoskeleton robot
(2011) Rajapakse, KD; Suluxon, K; Perera, AMCK; Gopura, RARC; Lalitharathne, SWHMTD; Hemapala, KTMU;
item: Conference-Full-text
Development of a Biomimetic Soft Robotic Knee Joint
(IEEE, 2023-12-09) Arachchige, UCD; Madusanka, MSG; Punsara, NAC; Kulasekera, AL; Gopura, RARC; Abeysooriya, R; Adikariwattage, V; Hemachandra, K
The knee joint is a complex joint in the human body that plays a significant role in locomotion activities in daily living. The development of robot legs and wearable devices that can perform human-like motions is limited due to the lack of a human-like knee joint. This paper presents a biomimetic soft robotic knee joint that performs human-like knee motion. It is actuated by means of bundled soft actuators that mimic the functionality of real human muscles. A vacuumactuated linearly contractile soft actuator is bundled to create the multifilament structure that drives a bicondylar knee joint. The design, fabrication, and performance characterization of the proposed multifilament actuators are presented. A test setup was developed to experimentally evaluate the knee model for seated posture knee flexion and extension. Experimental results show that the proposed knee joint can mimic the human knee joint in seated flexion and extension. The prototype developed can be further developed to develop a successful wearable device testing platform and as the foundation for the future development of prosthetic knees. This research contributes to the advancement of wearable devices and assistive technology, aiming to improve mobility and enhance the overall quality of life for individuals with limb disabilities.
item: Conference-Abstract
Development of a drug management system to ensure drug availability for patients in the hospital
(Faculty of Medicine, University of Moratuwa, 2024) Dilakshika, BGD; Dassanayake, NSS; Dunanja, WWR; De Seram, HGST; Dulanjana, WMM; Gopura, RARC; Gunaratne, NJDL; Kottahachhi, J; Peries, WANN; Talagala, I; Samarasinghe, T; Fernando, NS; Pasqual, D; Chandran,T; Shajahan, Z
Drug management is a critical component of healthcare, with precise medication dispensing being essential for both patient safety and efficient drug utilization. Globally, fully automated drug cabinets equipped with comprehensive drug tracking capabilities have been developed, along with advanced drug management software that assists healthcare providers in ensuring accurate and efficient medication management. In the Sri Lankan context drug management system heavily relies on manual criteria, causing errors and inefficiencies. This non-automated system negatively impacts patient care and resource management. This research aims to develop a hospital drug management system to ensure drug availability for patients.
item: Article-Abstract
Development of a layout model suitable for the food processing industry
Wanniarachchi, WNC; Gopura, RARC; Punchihewa, HKG
The food processing industry is a subset of the manufacturing sector with unique challenges. Among these, ensuring food hygiene and preventing contamination are two issues of prime importance. Hence, designers have to overcome such challenges when designing facilities suitable for food processing.The paper formulates a model that simplifies the layout planning process for the food processing facilities (FPF) in order to help the designers. A generalised framework that helps to visualise the Facilities Layout Problem (FLP) was initially developed. A layoutmodel for FPF was then developed considering the unique features that need to be present in the layout.The model classifies the areas of FPF into five: primary, secondary, utilities, warehouse, and administration based on the activities and the level of risk present in food processing. It further proposes specific locations for the five sections in the factory layout. In order to test the performance of the framework and the model, a case study was conducted in a malted milk powder processing facility in Sri Lanka by changing its layout according to the proposed model. The framework and the model showed promise in its implementation. However, the approach and the layout model need to be evaluated in further cases in order to ascertain their usability and performance. 1.
item: Conference-Abstract
Development of a surface muscle pressure monitoring system for wearable robotic devices
Chandrasiri, MDSD; Ranaweera, RKPS; Gopura, RARC
Monitoring of muscle activities of human limbs is essential for designing controllers of wearable robotic devices such as prosthetics, orthotics and exoskeletons. Human-robot interaction (HRI) is generally studied to control these devices and ascertain comfort levels of the wearer. Cognitive-HRI (cHRI) and physical-HRI (pHRI) are the two main types of HRI methods identified in literature. Surface electromyography (sEMG) signals of skeletal muscles are commonly used in cHRI methods to identify the motion intentions. However, sEMG signals are sensitive to the environmental conditions such as electric and magnetic disturbances. Alternatively, changes to muscle stiffness and volume are measured in pHRI methods. Accordingly, this paper presents a novel sensory system to detect motions of upper or lower limbs by monitoring surface-muscle pressure (SMP). It is comprised of specially designed ’pressurized-air-pouches’ made of silicone. Experiments were carried out with the developed SMP monitoring system to detect muscles activities during biceps curls. The results were compared against sEMG signals to evaluate the validity of the proposed method. The analysis indicated a strong correlation between the signals measured and verifies the potential of using SMP as an effective muscle activity sensing method.
item: Thesis-Full-text
Development of a vision aided reach-to-grasp path planning and controlling method for trans-humeral robotic prostheses
Madusanka, DGK; Gopura, RARC; Amarasinghe, YWR; Mann, GKI
This study proposes a reach-to-grasp path planning and controlling method for trans- humeral prostheses. Trans-humeral prostheses are used to replace the missing body part after the loss of upper limb (UL) above elbow. Reach-to-grasp paths refers to the paths taken by the human UL to reach towards an object with the intention of grasping. A trans-humeral prosthesis has been designed and fabricated with 5DOF. A simulation environment has been proposed using the design. Simulation environment consists of a virtual shoulder joint which can be actuated according to a natural human shoulder using an Inertial Measurement Unit (IMU). Prosthesis and the simulation environment has been used to experimentally evaluate the proposed path planning method. A reach-to-grasp path planning method combining Electromyography (EMG) signals and vision signals has been proposed. EMG Based Module (EBM) is capable of con- trolling prosthesis elbow motion e ectively with an accuracy of 92%. Visual Servoing Module (VSM) consists of a 2-1/2D visual servoing system to center the object of in- terest to the hand of the prosthesis and to correct the orientation. An object reaching algorithm has been proposed to reach towards the object. Later, the EBM and the VSM has been fused using an fusion lter. An improvement to the above method has been proposed to make the paths straight. It consists of a path generation module and a path tracking module. Path generation module is capable of generating a path towards the object. The object position is located and a path is generated from the current position of the prosthetic hand to the object position with the aid of vision. Path tracking module takes the prosthetic hand on the generated path considering shoulder motions. Two path tracking methods has been proposed: spatial path following method and Model Predictive Controller (MPC) based path tracking method. Proposed path planning method has been experimentally evaluated.