Conventional Robots Research Articles

Kinematics analysis of a medication delivery robot based on a 3-DOF manipulator

Medication delivery robots, as a type of service robots, are becoming increasingly important in the field of helping the elderly and disabled. Conventional drug delivery robots focus on mobility and often lack the ability to pick and place drugs independently. Based on this phenomenon, a new medication delivery robot structure based on a 3-DOF robot manipulator is designed in this paper. According to the motion process, the 3-DOF manipulator is modeled and simulated. Meanwhile, the influence of different trajectory planning methods on the drug taking and discharging process are compared, which provides theoretical and technical support for the research of robots in related fields.

Control System of Remote Maintenance Robots for the Fusion Device ITER

Remotely operated robotic systems are vital for maintaining the ITER plant—the world largest fusion device. To operate the ITER Blanket Remote Handling System (BRHS), its control system must have functionalities that are not familiar in conventional robot control systems; e.g., completely remote operation, multi-device control with reconfiguration during operations, and large-scale operation programming. We designed the control system to solve those problems: split the control system into the High-Level Control System, which has HMI functions, and Low-Level Control System, which has interfaces with robots, and enabled the remote operation from a different building; implemented abstract commands from the High-Level to the Low-Level Control system so that the robot devices can be reconfigured during an operation; developed hierarchical operation program that manages 2-year operations. We also designed specific functions of both levels of the control system and GUI of main components of the High-Level Control System.

Collaborative Continuum Robots for Remote Engineering Operations

In situ repair and maintenance of high-value industrial equipment is critical if they are to maintain the ability to continue vital operations. Conventional single-arm continuum robots have been proven numerous times to be successful tools for use in repair operations. However, often more than one arm is needed to ensure successful operation within several scenarios; thus, the collaborative operation of multiple arms is required. Here, we present the design and operating principles of a dual-arm continuum robot system designed to perform critical tasks within industrial settings. Here, presented are the design principle of the robotic system, the optimization-based inverse kinematic calculation of the 6-DoF continuum arms, and the collaborative operation strategy. The collaborative principle and algorithms used have been evaluated by a set of experiments to demonstrate the ability of the system to perform in situ machining operations. With the developed prototype and controller, the average error between planned and real toolpaths can be within 2.5 mm.

Agricultural Robot under Solar Panels for Sowing, Pruning, and Harvesting in a Synecoculture Environment

Currently, an agricultural method called SynecocultureTM has been receiving attention as a means for multiple crop production and recovering from environmental degradation; it helps in regreening the environment and establishing an augmented ecosystem with high biodiversity. In this method, several types of plants are grown densely, and their management relies mainly on manual labor, since conventional agricultural machines and robots cannot be applied in complex vegetation. To improve work efficiency and boost regreening by scaling-up Synecoculture, we developed a robot that can sow, prune, and harvest in dense and diverse vegetation that grows under solar panels, towards the achievement of compatibility between food and energy production on a large scale. We adopted a four-wheel mechanism with sufficient ability to move on uneven terrain, and a two orthogonal axes mechanism with adjusted tool positioning while performing management tasks. In the field experiment, the robot could move straight on shelving slopes and overcome obstacles, such as small steps and weeds, and succeeded in harvesting and weeding with human operation, using the tool maneuver mechanism based on the recognition of the field situation through camera image.

Mobile Robot Navigation Using Deep Reinforcement Learning

Learning how to navigate autonomously in an unknown indoor environment without colliding with static and dynamic obstacles is important for mobile robots. The conventional mobile robot navigation system does not have the ability to learn autonomously. Unlike conventional approaches, this paper proposes an end-to-end approach that uses deep reinforcement learning for autonomous mobile robot navigation in an unknown environment. Two types of deep Q-learning agents, such as deep Q-network and double deep Q-network agents are proposed to enable the mobile robot to autonomously learn about collision avoidance and navigation capabilities in an unknown environment. For autonomous mobile robot navigation in an unknown environment, the process of detecting the target object is first carried out using a deep neural network model, and then the process of navigation to the target object is followed using the deep Q-network or double deep Q-network algorithm. The simulation results show that the mobile robot can autonomously navigate, recognize, and reach the target object location in an unknown environment without colliding with static and dynamic obstacles. Similar results are obtained in real-world experiments, but only with static obstacles. The DDQN agent outperforms the DQN agent in reaching the target object location in the test simulation by 5.06%.

Achievements and future directions in self‐reconfigurable modular robotic systems

AbstractIn this study, a comprehensive review of achievements in the self‐reconfigurable modular robotics field and future directions are given. Self‐reconfigurable modular robots (SRMRs) are known as autonomous kinematic machines that can change their shape by rearranging the connectivity of their modules to perform new tasks, adapt to changing circumstances, and recover from damage. Versatility, reliability, and low‐cost are the fundamental promises of SRMRs when compared with conventional robots. This study emphasized the achievements in the field considering the promises and identified the gaps to be filled in the future. The main distinguishing feature of an SRMR is the capability of configuring its shape during operation. Flexibility in shape supported by appropriate controller strategies brings flexibility in task assignment. Classification of SRMRs is enriched by adding a new section based on assigned tasks to the robot. In addition, the classification based on mechanical and controller design aspects is thoroughly inspected in our study. A new subsection of material selection is introduced in the mechanical design aspects section. Adding these sections to the classification is the main difference between our study and the previous review studies. It is expected that the SRMRs field will have more interactions with materials science in the future. The study is concluded by emphasizing the promises of SRMRs and giving a future vision of the field.

Design and Construction of a Snake-Like Robot Implementing Rectilinear and Sidewinding Gait Motions

Bio-inspired robots offer locomotion versatility in a wide variety of terrains that conventional robots cannot access. One such bio-inspired platform is snake-like robots, which are mechanisms designed to move like biological snakes. The aim of this paper was to implement and validate, through comparison in real and simulation tests on flat terrain, the design of a snake robot that allows movements in two perpendicular planes, by the application of three-dimensional locomotion modes. The prototype robot had a modular and sequential architecture composed of eight 3D printed segments. The necessary torques for each motor are found by means of a simulation in Matlab – Simulink and the SimScape tool. The Webots mobile robotics simulator was used to create a parameterized virtual model of the robot, where two types of gaits were programmed: sidewinding and rectilinear. Results showed that the robot undertakes lower than 1 second in execution time to reach the total distance in each of the proposed marches when comparted to the simulation. In addition, mean differences of 6 cm for the distances during the sidewinding mode experiment and 1.2 cm in the deviation in the rectilinear mode on flat terrain were obtained. In conclusion, there is a great similarity between the simulation tests and those performed with the actual robot, and it was also possible to verify that the behavior of the prototype robot is satisfactory over short distances.

Dual-Segment Continuum Robot With Continuous Rotational Motion Along the Deformable Backbone

The hyper redundancy and flexibility of continuum robots have made them attractive to replace conventional rigid-link robots in many applications. Although the robot body can be bent to different directions as needed, rotation along the backbone is not a feature available in many continuum robot designs. In this article, we propose a pneumatic-driven, dual-segment continuum robot with the capability of providing continuous rotation along the deformed backbone (CRADB) at a particular point. A slip ring was employed to enable rapid coupling/decoupling between the air supply and different chambers of the robot, while a stepper motor with adjustable speed was adopted to provide the additional rotational motion. A novel control scheme based on optimization was developed to compute the required shape configuration under different modes. Control schemes toward fast deformation motion and CRADB motion have been, respectively, built. Experiments were conducted to compare the performance in positioning the robot’s tip with and without the additional degree of freedom. The ability to enable continuous rotation after positioning at different points was also tested to demonstrate its performance in various potential applications.

Series Elastic Actuators-Driven Parallel Robot With Wide-Range Impedance Realization for Balance Assessment and Training

In this article, a novel robotic device is proposed that can realize a large range of compliance and a force sufficient to achieve human-balance training. The proposed device is called a virtual ground robot (VGR) and consists of a 3-degree-of-freedom parallel mechanism, which is driven by three series elastic actuators (SEAs). The proposed VGR can produce a large force and impedance overcoming the limitation of SEA using properly designed parallel legs, 3-PRRS, which can also reduce the size of the VGR. As a result, the proposed VGR can achieve 2.38-times stiffness ellipsoid as a conventional 3-RPS parallel robot. It can also achieve significantly large compliance by exploiting the advantages of SEAs, which have not been realized using conventional motion platforms. The dynamics and kinematics of the VGR are investigated from the SEA space to the entire task space, based upon which, the spatial impedance control of the VGR is designed by utilizing the robust force control of the SEA. The VGR is utilized as a device for measuring and training the balance of a human; a person can stand on the VGR, and balance-related values such as force, position, and center of the pressure are observed and controlled by the robot. The features and performance of the developed robot were theoretically examined and validated experimentally.

Design and Analysis of Mini Fire Fighting Robot

Abstract: Fire Incident is a disaster that can potentially cause the loss of life, property damage and permanent disability to the affected victim. The Victim of Fire Incident can also suffer from prolonged psychological and trauma. Fire fighters are primarily tasked to handle fire incidents, but they are often exposed to higher risks when extinguishing fire, especially in hazardous environments such as in nuclear power plant, petroleum refineries and gas tanks. They are also faced with other difficulties, particularly if fire occurs in narrow and restricted places, as it is necessary to explore the ruins of buildings and obstacles to extinguish the fire and save the victim. With high barriers and risks in fire extinguishment operations, technological innovations can be utilized to assist firefighting. Therefore, this paper presents the design of a firefighting robot dubbed that can extinguish fire without the need for fire fighters to be exposed to unnecessary danger. It is designed to be compact in size than other conventional fire-fighting robot to ease small location entry for deeper reach of extinguishing fire in narrow space. It is also equipped with an ultrasonic sensor to avoid it from hitting any obstacle and surrounding objects, while a flame sensor is attached for fire detection. This resulted in It demonstrating capabilities of identifying fire locations automatically and ability to extinguish fire remotely at distance

A perspective on plant robotics: from bioinspiration to hybrid systems

As miscellaneous as the Plant Kingdom is, correspondingly diverse are the opportunities for taking inspiration from plants for innovations in science and engineering. Especially in robotics, properties like growth, adaptation to environments, ingenious materials, sustainability, and energy-effectiveness of plants provide an extremely rich source of inspiration to develop new technologies—and many of them are still in the beginning of being discovered. In the last decade, researchers have begun to reproduce complex plant functions leading to functionality that goes far beyond conventional robotics and this includes sustainability, resource saving, and eco-friendliness. This perspective drawn by specialists in different related disciplines provides a snapshot from the last decade of research in the field and draws conclusions on the current challenges, unanswered questions on plant functions, plant-inspired robots, bioinspired materials, and plant-hybrid systems looking ahead to the future of these research fields.

A novel design for fully constrained planar Cable-Driven Parallel Robots to increase their wrench-feasible workspace

Cable-Driven Parallel Robots (CDPRs) are a special kind of parallel manipulators that offer several advantages compared to the conventional rigid parallel robots. One of the most interesting advantages is their ability to cover large working areas since long cables can be easily coiled. The practical limitation on the permissible cable tensions, however, causes a considerable decrease in the size of the wrench-feasible workspace (WFW) of these robots. To solve this problem in the case of fully-constrained planar CDPR with 3 degrees-of-freedom, this work proposes a novel design, based on the addition of passive carriages to the robot frame. It allows to significantly reduce the variation in the cables direction and therefore in the cable forces, resulting in a notable increase in the size of the WFW. This work presents the kinematic and static models of the new robot and proposes a preliminary approach for the resolution of the static equilibrium. The WFW of the new robot is investigated in different situations and compared to that of a conventional planar CDPR, showing a significant improvement in every case studied.

Design and Feasibility Study of MRG-Based Variable Stiffness Soft Robot.

The conventional pneumatic soft robot has the problem of insufficient stiffness, while in the magnetorheological soft robot, the magnetic field provided by electromagnet has the disadvantage of oversized structure and poor flexibility. This paper presents a variable stiffness pneumatic soft robot based on magnetorheological grease (MRG) to solve these problems. Its three soft fingers cooperate with the adjustable gripper to adjust the gripping range for the robot hand, and it is used to provide gripping driving force through the bending drive. The MRG layer is designed on the gripping surface to provide adaptivity and rigid support for the gripped objects. A magnetic-air structure consisting of a Halbach array and Halbach array actuator is designed inside the soft fingers to provide a flexible magnetic field for the MRG layer. Theoretical and simulation analysis is carried out, and the results show that the state of the MRG changes and the stiffness of the clamping surface changes under the working pressure of 30 kPa. Finally, the experiment further proves the variable and high adaptivity of the surface stiffness of the gripping surface to reduce the damage to the gripped objects.

Modeling and Analysis of Tendon-Driven Parallel Continuum Robots Under Constant Curvature and Pseudo-Rigid-Body Assumptions

Abstract This article unifies the approaches of kinematic and static modeling, and singularity analysis for tendon-driven parallel continuum robots under constant curvature as well as pseudo-rigid-body assumptions with those implemented in conventional rigid parallel robots. Constraint conditions are determined for the legs of this type of parallel continuum robots based on which the velocity equations and Jacobian matrices are derived. These are further exploited for inverse kinematic and singularity analysis. Static models for the robot as well as for each of the continuum links under pseudo-rigid-body assumption are derived. Finally, a simulation example is given to validate the kinematic models. It is shown that singularities can be determined using Grassmann line geometry or by detecting the numerical values of three performance indices.

Single-port robotic surgery for mediastinal tumors using the da vinci SP system: Initial experience.

Studies of single-port robot-assisted thoracic surgery (RATS) using the da Vinci SP system, which uses a smaller surgical incision than the conventional multiport robot, have yet to be reported because of its smaller operating range. We report our initial experience using the da Vinci SP system in thoracic surgery for the resection of mediastinal tumors that requires a smaller workspace. Two patients diagnosed with superior mediastinal tumors underwent RATS performed with the da Vinci SP surgical system in January 2022. We used three-dimensional reconstruction to preoperatively determine the surgical incision. This is the first report of single-port RATS using the SP system in China. R0 resection was achieved in both operations without complications. Operation times and bleeding volumes were similar to the use of multiport RATS. No perioperative complications occurred. The da Vinci SP system can be used for the resection of superior mediastinal tumors. Case selection and preoperative planning should be performed prior to these surgeries.

A human augmentation device design review: supernumerary robotic limbs

PurposeSupernumerary robotic limbs (SRLs) are a new type of wearable robot, which improve the user’s operating and perceive the user’s environment by extra robotic limbs. There are some literature reviews about the SRLs’ key technology and development trend, but the design of SRLs has not been fully discussed and summarized. This paper aims to focus on the design of SRLs and provides a comprehensive review of the ontological structure design of SRLs.Design/methodology/approachIn this paper, the related literature of SRLs is summarized and analyzed by VOSviewer. The structural features of different types of SRLs are extracted, and then discuss the design approach and characteristics of SRLs which are different from typical wearable robots.FindingsThe design concept of SRLs is different from the conventional wearable robots. SRLs have various reconfiguration and installed positions, and it will influence the safety and cooperativeness performance of SRLs.Originality/valueThis paper focuses on discussing the structural design of SRLs by literature review, and this review will help researchers understand the structural features of SRLs and key points of the ontological design of SRLs, which can be used as a reference for designing SRLs.

MEMS-Based Micro Sensors for Measuring the Tiny Forces Acting on Insects.

Small insects perform agile locomotion, such as running, jumping, and flying. Recently, many robots, inspired by such insect performance, have been developed and are expected to be smaller and more maneuverable than conventional robots. For the development of insect-inspired robots, understanding the mechanical dynamics of the target insect is important. However, evaluating the dynamics via conventional commercialized force sensors is difficult because the exerted force and insect itself are tiny in strength and size. Here, we review force sensor devices, especially fabricated for measuring the tiny forces acting on insects during locomotion. As the force sensor, micro-force plates for measuring the ground reaction force and micro-force probes for measuring the flying force have mainly been developed. In addition, many such sensors have been fabricated via a microelectromechanical system (MEMS) process, due to the process precision and high sensitivity. In this review, we focus on the sensing principle, design guide, fabrication process, and measurement method of each sensor, as well as the technical challenges in each method. Finally, the common process flow of the development of specialized MEMS sensors is briefly discussed.

NARX Neural Network for Safe Human–Robot Collaboration Using Only Joint Position Sensor

Background: Safety is the very necessary issue that must be considered during human-robot collaboration in the same workspace or area. Methods: In this manuscript, a nonlinear autoregressive model with an exog-enous inputs neural network (NARXNN) is developed for the detection of collisions between a manipulator and human. The design of the NARXNN depends on the dynamics of the manipulator’s joints and considers only the signals of the position sensors that are intrinsic to the manipulator’s joints. Therefore, this network could be applied and used with any conventional robot. The data used for training the designed NARXNN are generated by two experiments considering the sinusoidal joint motion of the manipulator. The first experiment is executed using a free-of-contact motion, whereas in the second experiment, random collisions by human hands are performed with the robot. The training process of the NARXNN is carried out using the Levenberg–Marquardt algorithm in MATLAB. The evaluation and the effectiveness (%) of the developed method are investigated taking into account different data and conditions from the used data for training. The experiments are executed using the KUKA LWR IV manipulator. Results: The results prove that the trained method is efficient in estimating the external joint torque and in correctly detecting the collisions. Conclusions: Eventually, a comparison is presented between the proposed NARXNN and the other NN architectures presented in our previous work.

Adaptive Fuzzy Control of a Cable-Driven Parallel Robot

Cable robots are a type of parallel robot in which cables have replaced the usual rigid arms. In cable robots, due to the tensile strength of the cable, the workspace analysis is much more complex than in conventional robots. In this paper, we design an adaptive fuzzy controller for a cable-driven parallel robot (CDPR). In the proposed controller, the results show that the accuracy of the system performance in tracking the reference value as well as the controller performance speed is better than that of the robust method. In one of the simulation modes, the performance speed of the control system for convergence is reduced and its error is very small, which indicates the proper performance of the proposed adaptive fuzzy method. It should be noted that all simulations are performed in a MATLAB software environment.

Stand-Up Assistive Devices Allowing Patients to Perform Voluntary Movements Within the Safety Movement Tolerance

This paper proposes a novel standing assistance robot, which realizes voluntary movements of the patient within a safety motion range. In previous studies, conventional assistive robots did not require patients to use their own physical strength to stand, which leads to decreased strength in the elderly. Such general assistive robots helped patients by using a fixed motion reference pathway in spite of their original intention, and as a result, these robots failed to use the physical strength of the patients. Therefore, this study proposes a novel method for assisting the patient to stand up safely while using their physical abilities, by determining the range of movements that can be safely performed from the patient's physical condition, and allowing the patient to move freely within this range. The standing motion is a set of different movements: inclining the trunk forward, lifting the trunk and extending the trunk. In this study, the range of movements in which the patient can safely stand in each movement was determined in terms of body stability and the muscle output that the patient can generate. Furthermore, this study proposes a robot control method that allows movements based on the patient's free will if the patient's posture is within the safety tolerance, and corrects the movements when the patient's posture is estimated to fall outside of it. Proposed idea is implemented to our new prototype and its effectiveness is verified by experimental results with elderly subjects who lives in the nursing care house.