1,720,980 research outputs found
Minto, R A C, Singapore
No full textThis record was harvested from a previous catalogue system and will be withdrawn in 2025. Information in this record may be superseded or incomplete. Visit this record in UMA's new catalogue at: https://archives.library.unimelb.edu.au/nodes/view/405388Surname: MINTO. Given Name(s) or Initials: R A C. Military Service Number or Last Known Location: SINGAPORE. Missing, Wounded and Prisoner of War Enquiry Card Index Number: 21305.243129
Item: [2016.0049.37666] "Minto, R A C, Singapore
Exploiting the Redundancy of Cable Suspended Parallel Robots for the Actuation of the End-Effector
No full textCable-driven parallel robots are a class of parallel robots whose performance, and lightweight and inexpensive design are of interest for industrial applications. For the design to be effective in the industrial field, an end-effector should be designed, and traditional end-effectors require an external power source for the actuation, which can be limiting in larger workspaces. This work presents the design of an end-effector which exploits the redundancy in the tension configuration to actuate a gripper. To fully exploit the variation in cable tension, a force-transmission mechanism is presented. Given the influence of the end-effector Cartesian position on the tension configuration, this work presents the available gripping force in the robot workspace. The results show a promising solution for the design, which is effective in grasping a mass of 1.5 kg in the workspace
A sensorless approach for cable failure detection and identification in cable-driven parallel robots
Full text linkCable-driven parallel robots (CDPRs) are a particular class of parallel robots that provide several advantages that may well be received in the industrial field. However, the risk of damage due to cable failure is not negligible, thus procedures that move the end-effector to a safe pose after failure are required. This work aims to provide a sensorless failure detection and identification strategy to properly recognize the cable failure event without adding additional devices. This approach is paired with an end-effector recovery strategy to move the end-effector towards a safe position, thus providing for a complete cable failure recovery strategy, which detects the failure event and controls the end-effector accordingly. The proposed strategy is tested on a cable-driven suspended parallel robot prototype composed of industrial-grade components. The experimental results show the feasibility of the proposed approach
A Comparison of Control Strategies for Collaborative Mobile Robots
No full textMobile collaborative robots are more and more common in the industrial scenario, increasing the workspace of collaborative manipulators and, thus the shared workspace. This work compares different admittance controllers for mobile collaborative robots. In particular, we focused on an application where a human operator manually moves a mobile collaborative robot by applying forces to a collaborative manipulator attached to the mobile platform. Three different forms of admittance control were presented and tested with experiments on a real mobile robot. Finally, the capabilities of these controllers were compared
Task allocation model for human-robot collaboration with variable cobot speed
Full text linkNew technologies, such as collaborative robots, are an option to improve productivity and flexibility in assembly systems. Task allocation is fundamental to properly assign the available resources. However, safety is usually not considered in the task allocation for assembly systems, even if it is fundamental to ensure the safety of human operator when he/she is working with the cobot. Hence, a model that considers safety as a constraint is here presented, with the aim to both maximize the productivity in a collaborative workcell and to promote a secure human robot collaboration. Indexes that consider both process and product characteristics are considered to evaluate the quality of the proposed model, which is also compared with one without the safety constraint. The results confirm the validity and necessity of the newly proposed method, which ensures the safety of the operator while improving the performance of the system
Experimental investigation of a cable robot recovery strategy
Full text linkDeveloping an emergency procedure for cable-driven parallel robots is not a trivial process, since it is not possible to halt the end-effector by quickly braking the actuators as in rigid-link manipulators. For this reason, the cable robot recovery strategy is an important topic of research, and the literature provides several approaches. However, the computational efficiency of the recovery algorithm is fundamental for real-time applications. Thus, this paper presents a recovery strategy adopted in an experimental setup consisting of a three degrees-of-freedom (3-DOF) suspended cable robot controlled by an industrial PC. The presentation of the used control system lists the industrial-grade components installed, further highlighting the industrial implication of the work. Lastly, the experimental validation of the recovery strategy proves the effectiveness of the work
Robotic Additive Printing of Cylindrical Auxetic Structures
No full textAdditive manufacturing technologies represent an interesting solution to aid companies to offer a wide range of customized products. Furthermore, they allow printing complex lattice and auxetic structures. The use of robot manipulators for 3D printing allows overcoming several limitations of traditional additive manufacturing systems, i.e. low surface quality (stair-casing effects) and undesirable anisotropic properties, so as to print complex geometries on curved surfaces. This work presents an experimental setup designed to print cylindrical auxetic structures composed of a 3D printer and a robotic arm. The system produces the part without any assembly and avoiding stair-case effects. Furthermore, using the robot for moving the printing based simplified the control system and allows for simpler printing devices
A framework for the integration of traditional and collaborative robotics
No full textIn recent years, a new type of robotic manipulator, i.e., collaborative robots (cobots), was introduced in the market. Their ability to share the workspace with the operator without any safety fences allows automating tasks that were too difficult or too expensive to automate. Moreover, collaborative workcells merge the flexibility of the human operator and the accuracy of automated systems. However, they are usually separated from the main industrial plant, reducing their influence on the process. Hence, a framework to connect traditional and collaborative robotics is presented in this work. The framework is developed in three layers with a top-down approach, where a first offline layer will solve the task scheduling problem of a human-robot collaborative workcell. Due to the unpredictability of the human operator, it is important to develop a second layer to monitor the operator and dynamically adapt the cobot. A possible implementation with depth cameras is presented along with a control scheme. Lastly, a third layer is responsible for the connection between the collaborative workcell and the other devices connected to the process line. A case study presents a possible application of the proposed approach
Control Model for Collaborative Manufacturing: an integrated opened framework for Human-Robot Collaboration.
No full textCollaborative robots represent an interesting solution to automate tasks that were too difficult or too expensive to automate since they merge the flexibility of a human operator and the accuracy of automated systems. This work presents a framework developed in three levels with a top-down approach. A first offline level will solve the task scheduling problem of a human-robot collaborative workcell addressing both logistic and robotic aspects, represented by physical interferences and performance indexes. A second level will manage the shared workspace in real-time. These first two levels, due to their general nature, will be described in greater detail. The possible application and validation of the model to a specific case study will be discussed in the third level, which will describe the connection of the model towards different device
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