Mobile Robot System Research Articles

Towards the use of robotic systems at nuclear facilities

Abstract The article addresses the matter of the mobile robotic systems (MRS) application at nuclear industry and nuclear energy facilities. Three main types of tasks solved with the help of MRS in order to ensure safety and reduce the radiation load on personnel are described. The scope of application and general requirements for such MRS, typical technological operations, control modes and human-robot interaction are discussed. It is shown that highly specialized robots are mainly used and that their design doesn’t imply a prompt replacement of the payload and adaptation to various tasks. It is noted that most of the modern MRS designed to operate at radiation-hazardous facilities are still teleoperated. The necessity of creating multifunctional modular reconfigurable MRS of various standard-size groups for use at nuclear facilities and increasing the level of their autonomy is substantiated. Key words Mobile robotic system, UGV, nuclear facility, teleoperation, supervisory control. Acknowledgements This work was carried out within the framework of the state assignment of the Ministry of Education and Science of Russia No. 075-00913-21-00 dated December 25, 2020 «Development of proposals for improving the state scientific, technical and industrial policy and popularizing achievements in the field of robotics based on an analysis of trends in the development of robotics in Russia and abroad».

Trajectory Tracking Control of a Mobile Robot with the ROS System

This article provides a simulation and laboratory study of a control system for a two-wheeled differential-drive mobile robot with ROS system. The authors propose an approach to designing a control system based on a parametric model of the robot’s dynamics. The values of unknown parameters of the dynamic model have been determined by means of a Levenberg-Marguardt identification method. By comparing the desired trajectories with those obtained from simulation and laboratory tests, and based on errors analysis, the correctness of the model parameter identification process and the control system operation was then determined.

Hybrid implementation of neuromorphic system for robot control

Abstract The article proposes a new approach to the implementation of a neuromorphic system based on a hybrid model of a neuron, made in a neuro-fuzzy basis. The closest analogue, the Neo-fuzzy neuron model, is described. A neurological cluster model, previously developed with the participation of the authors, was chosen as a prototype for constructing a hybrid model. The basic procedures for processing and teaching this model to map a given function, as well as additional procedures for coding pulse inputs and synthesis of pulse outputs are presented. Using these procedures, a new hybrid model of a spike neuron has been implemented, which reflects the function of the traditional model of Izhikevich's neuron. It is shown that the hybrid model requires less computing resources. On the basis of the new version of the hybrid model, a spike neuromorphic network was developed and tested to control the movements of a mobile robot along a given trajectory. It is assumed that, using a hybrid version of the neuron model, it is easier to implement a hardware version of spike neuromorphic networks than using neuron models based on differential equations. On the basis of such hardware-implemented networks, it is possible to create effective neuromorphic control systems for mobile robots. Key words Neuromorphic system, spike neuromorphic network, hybrid neuron model, neuron-fuzzy basis, mobile robot control. Acknowledgements This work was done as the part of the state task of the Ministry of Education and Science of Russia No. 075-00913-21-01 «Development and study of new architectures of reconfigurable growing neural networks, methods and algorithms for their learning».

Trajectory Tracking of Mobile Robot Based on Improved Hierarchical Sliding Mode Control

A control algorithm based on PD control and non-singular terminal hierarchical sliding mode control is proposed for tracking control of mobile robot systems. First establish a dynamic model of mobile robot under cartesian coordinate system, the system can be divided into subsystems of posture and position, attitude subsystem by using PD control, location subsystem using non-singular terminal hierarchical sliding mode control, the introduction of the system state higher order term, improve the system in the convergence speed and stability of the sliding surface, the system reaches a steady state in a limited time; Finally, the stability of the system is proved theoretically, and the effectiveness of the control method is verified by simulation.

Adaptive full-state constrained tracking control for mobile robotic system with unknown dead-zone input

This paper studies the adaptive neural networks (NNs) tracking control problem for a class of mobile robot systems with full-state constraints. First, to compensate for the adverse effects of the unknown dead-zone input, which is ubiquitous in mobile robot motors, a new robust control algorithm is put forward by the use of adaptive control technique. Then, a new unified barrier function (UBF) is constructed to deal with the problem of state constraints. Different from traditional barrier Lyapunov function (BLF) methods, which can only constrain the error of the system state and virtual controller, our proposed control method can constrain the system state directly by introducing a novel nonlinear transformation function and a new coordinate transformation. It’s worth noting that the UBF can be utilized to deal with both constrained and unconstrained cases by resizing parameters without changing the control structure. Furthermore, adaptive NNs are introduced to approximate the uncertainty of the system. Finally, based on the Lyapunov stability theory, it is proved that all signals in the closed-loop system are ultimately bounded and the full-state constraints are never violated. The effectiveness of the control method is verified on simulation examples and a mobile robot experimental platform.

A proposed ontology to support the hardware design of building inspection robot systems

Due to the growing number of architecturally complex buildings built in recent decades, mobile building inspection robot systems are required to operate in increasingly complex environments. This leads to higher requirements for their hardware design. The existing literature on the design of building inspection robots has implicitly mentioned the impact of building environments and building defects on defining robot hardware design requirements. However, the explicit representation of what information is required to define a specific hardware requirement is stimissing. To fill this gap, this paper presents an ontology that provides an overview of the building and inspection domain objects that affect the determination of robot hardware design requirements (RoboDesign). It also explores the relationship between specific robot hardware requirements and features of complex buildings and their defects. The RoboDesign ontology integrates two main domain ontology models including a Robot System Model and a Building and Defect Model. A content evaluation and an automated consistency checking are conducted for the internal evaluation of the ontology. Additionally, the proposed ontology is implemented in two wall-climbing inspection robot design cases to check if the investigation of the robot’s application environment is comprehensive. The validation results also demonstrate that the use of the proposed ontological model allows to efficiently retrieve information required to determine a particular hardware requirement.

Development of a Manually Operated Mobile Robot That Prints Construction Site Layouts

Chalk lines are used to print layouts in construction sites to indicate the location of attaching or cutting objects; printing depends on the skills of workers and is suitable for small-scale work. Moreover, this type of work requires a precise measurement process, which is time-consuming, to avoid errors. Thus, discrepancies between blueprints and construction site layouts can occur if construction plans and management are not uniformly aligned. To improve the traditional floor-layout-printing technique on construction sites, this study introduces a manually operated mecanum-wheeled mobile robot in the preliminary stage, i.e., before the development of a full-fledged automated system. This manually operated robot helps determine the technologies required for robotic automation. In the development process, layout-printing technology is classified into a marking toolkit, control system that can be manually operated, and mobile driver. To improve layout-printing quality, this study adopted a mecanum-wheeled design to improve mobility. In this study, applied tests are required to consider the site environment for automatically marking floor layout prints. To determine the applicability of the developed technology, this study conducted a field applicability experiment with a pen-type marking module and laser-type toolkit. The experiment confirmed that layout printing based on environmental changes on the construction site can be manually performed using the mobile robot system. To automatically mark floor-layout-printing work, it is necessary to consider the floor characteristics on the construction site. In addition, this experiment shows that the newly applied laser toolkit technology can be applied to layout printing within 12 mm from the floor. To apply this mechanism to a mobile robot that can automate layout printing, it is necessary to technically enhance the optimization of marking quality, e.g., floor separation distance and marking thickness.

CALIBRATION OF A MULTI-SENSOR WHEELED ROBOT FOR THE 3D MAPPING OF UNDERGROUND MINING TUNNELS

Abstract. Mobile robotic systems show great potential for automation and a vast selection of tasks in everyday life and industrial facilities. The most important fields of application are related to limiting human exposure to harmful conditions and greatly increasing work safety, among other cost-driven factors. One of these field is the mining industry. While in surface mining automation of several tasks is already being done e.g., using drones, in GNSS-denied underground environments using such innovation at a market-ready level is significantly more challenging, also due to the difficulties of spatial data acquisition needed, e.g., for navigation. This paper presents a system calibration procedure (6D pose estimation) of a multi-sensor mobile robot developed for inspecting underground mining tunnels and infrastructures. We introduce the sensors setup for the acquisition of spatially-related data (images, laser scans) and propose a multi-step calibration workflow of the different perception devices, such as RGB, thermal cameras and LiDARs, in a coherent reference frame. The quality of subsequent calibration stages is investigated based on the visual results and derived statistical measures. The propose procedure allowed the relative pose estimation of all sensors without specialized setups and targets, utilizing only natural urban scenes and a standard checkerboard pattern.

2D Mapping of Mobile Robot Based on micro-ROS

This paper proposes micro-ROS-based mobile robot system development and 2D mapping. Micro-ROS uses the micro-XRCE-DDS middleware to communicate with ROS2 in an extremely resource-constrained microcontroller environment. The mobile robot control system adopts a layered control method. The x64 PC equipped with Ubuntu ROS foxy is used as the main control platform, the olimex-stm32-E407 equipped with micro-ROS is used as the motion control layer, and the stm32F103 microcontroller is the underlying driver core. The forward and inverse kinematic equations are obtained through the analysis of the robot kinematics model. Through the interaction between the ROS2 nodes in the micro-ROS environment and the ROS2 nodes on the PC side, the cartographer algorithm is used to verify the effectiveness of the micro-ROS-based mobile robot system.

Locomotion Systems for Land-based Mobile Robots

Locomotion Systems for Land-based Mobile Robots

Sampling visual SLAM with a wide‐angle camera for legged mobile robots

AbstractPrecise localisation and navigation are the two most important tasks for mobile robots. Visual simultaneous localisation and mapping (VSLAM) is useful in localisation systems of mobile robots. The wide‐angle camera has a broad field of vision and more abundant information on images, so it is widely used in mobile robots, including legged robots. However, wide‐angle cameras are more complicated than ordinary cameras in the design of visual localisation systems, and higher requirements and challenges are put forward for VSLAM technologies based on wide‐angle cameras. In order to resolve the problem of distortion in wide‐angle images and improve the accuracy of localisation, a sampling VSLAM based on a wide‐angle camera model for legged mobile robots is proposed. For the predictability of the periodic motion of a legged robot, in the method, the images are sampled periodically, image blocks with clear texture are selected and the image details are enhanced to extract the feature points on the image. Then, the feature points of the blocks are extracted and by using the feature points of the blocks in the images, the feature points on the images are extracted. Finally, the points on the incident light through the normalised plane are selected as the template points; the relationship between the template points and the images is established through the wide‐angle camera model, and the pixel coordinates of the template points in the images and the descriptors are calculated. Moreover, many experiments are conducted on the TUM datasets with a quadruped robot . The experimental results show that the trajectory error and translation error measured by the proposed method are reduced compared with the VINS‐MONO, ORB‐SLAM3 and Periodic SLAM systems.

Design of Orbital Mobile Robot System for Electroplating Production Line

For different electroplating processes, there are many automatic electroplating production lines at present, but there is still no long-distance electroplating production line for small batches and multiple varieties of plated parts. Therefore, this paper proposes a set of orbital mobile robot systems to improve the production efficiency and quality of electroplating and reduce the uncertainty of manual control. The hardware of the system is composed of an orbital car and a robotic arm. The orbital car includes mobile positioning and a holding brake mechanism and the robotic arm adopts KUKA kr20-r2100 industrial robot. According to the logic of moving and grabbing, the control framework of the system is determined. A lot of field experiments show that the designed system can adapt to the factory environment and automatically complete the scheduling tasks assigned by the system.

Application of robotics during the decommissioning of nuclear facilities: state of the art and development prospects

The article deals with the application of mobile robotic systems (UGV) during the decommissioning of nuclear industry and energy facilities. It is shown that, in contrast to the recovery from accidents, when usually the work is carried out in an unknown unstructured environment, which implies damage to buildings, blockages, flood zones, etc., decommissioning is carried out in a rather complex, but well known environment according to a pre-developed plan. The general requirements for such UGVs are discussed, based on the features and practice of their application.

The Construction of Robot Experiment Teaching Course for the Cultivation of Outstanding Talents in Intelligent Manufacturing

With the continuous progress of science and technology, intelligent manufacturing has become one of the main directions of industrial development, and training outstanding talents for it has become a historical mission that relevant universities must complete. As an important basis for realizing intelligent manufacturing, robot learning and application naturally become a key link in the cultivation of outstanding talents in intelligent manufacturing. On the basis of theoretical learning, the construction of robot experimental teaching courses can truly cultivate outstanding talents with practical application ability. This paper takes the construction of "Autonomous Navigation and Obstacle Avoiding Mobile Robot System Design Experiment" as an example to analyze how to build a student centered, interest oriented, practice based, and education oriented robot experiment teaching course that combines reality with fiction. This experimental course is based on scientific research projects, built around the student center, and oriented to teaching needs. It includes robot autonomous positioning and navigation, autonomous path planning, full coverage path planning, etc. Its experimental content, teaching methods, and concept design can be applied to the construction of similar experimental courses, with great promotion and application value.

(Retracted) Research on motion control method of double rear wheel independent drive robot

The mobile robot receives control commands through wireless communication in real time, and moves flexibly with desired speed, direction, and trajectory. The motion control system directly affects the overall performance of the robot system. Here, we establish the kinematic model of the independent dual rear wheel drive mobile robot, design the linear speed control rate and angular speed control rate, design the inversion controller through the backstepping method, and carry out offline simulation and real-time control research on the dual rear wheel independent drive mobile robot system. Compared with other linearization control methods, the backstepping method does not need to linearize the system, and it directly designs the recursive controller of the system while retaining the nonlinear term in the controlled object, so the designed controller has strong robustness.

Metaheuristic Approach to Synthesis of Suspension System of Mobile Robot for Mining Infrastructure Inspection.

The article describes the problem of geometric synthesis of the inspection robot suspension system, designed for operation in difficult conditions with the presence of scattered obstacles. The exemplary application of a mine infrastructure inspection robot is developed and supported by the ideas. The brief introduction presents current trends, requirements and known design approaches of platforms enabled to cross the obstacles. The idea of a nature-inspired wheel-legged robot is given, and the general outline of its characteristics is provided. Then the general idea of kinematic system elements selection is discussed. The main subject of geometrical synthesis of the chosen four-bar mechanism is described in detail. The mathematical model of the suspension and connections between the parts of the structure is clarified. The well-known analytical approach of brute force search is analyzed and validated. Then the method inspired by the branch and bound algorithm is developed. Finally, a novel application of the nature-inspired algorithm (the Chameleon Swarm Algorithm) to synthesis is proposed. The obtained results are analyzed, and a brief comparison of methods is given. The successful implementation of the algorithm is presented. The obtained results are effectively tested with simulations and experimental tests. The designed structure developed with the CSA is assembled and attached to the prototype of a 14-DOF wheel-legged robot. Furthermore, the principles of walking and the elements forming the control structure were also discussed. The paper is summarized with the description of the developed wheel-legged robot LegVan 1v2.

Telepresence Robot System for People with Speech or Mobility Disabilities.

Due to an increase in the number of disabled people around the world, inclusive solutions are becoming a priority. People with disabilities may encounter many problems and may not be able to easily participate in various activities due to physical barriers, which may sometimes cause them to be frustrated and embarrassed. Recently, the emerging telepresence robot technology has been proposed to enable people with disabilities to increase their presence by incorporating information and communications technology (ICT) into robotics platforms. Therefore, in this paper we conduct a comprehensive analysis using comparative and elicitation studies to understand the current state of mobile telepresence robot systems and to identify the gaps that must be filled. This paper further contributes to the literature by proposing a novel telepresence robot system that adapts text-to-speech (TTS) and ICT technologies with robotics for its use as an assistant. To the authors' knowledge, the proposed system is the first MRP system that supports speech impairment and introduces emotion components into its communication function. It includes an operator site (mobile) and a remote site (robot) to allow users to control the robot from a distance and communicate with others in remote locations. It allows the user to physically interact with people and show certain emotions through the robot in remote locations, or it can accompany them to speak on their behalf. It can provide agency for both remote and in-class users through emoji-based communication and audio-video streaming with recording functionality. As shown at the end of this paper, the system was tested with 30 people, some of whom had mobility or speech disabilities, showing that the user acceptance score was above 95% and that people with disabilities liked to interact with other people using the proposed system. The users appreciated having the ability to control the robot from a distance and praised the capability to show their emotions through the robot emoji motions and to control the audio-video streaming. From this study, we conclude that the proposed telepresence system could be an asset to people with speech and mobility disabilities and could help them feel physically present in various places.

Kinematics Calibration and Validation Approach Using Indoor Positioning System for an Omnidirectional Mobile Robot.

Monitoring and tracking issues related to autonomous mobile robots are currently intensively debated in order to ensure a more fluent functionality in supply chain management. The interest arises from both theoretical and practical concerns about providing accurate information about the current and past position of systems involved in the logistics chain, based on specialized sensors and Global Positioning System (GPS). The localization demands are more challenging as the need to monitor the autonomous robot's ongoing activities is more stringent indoors and benefit from accurate motion response, which requires calibration. This practical research study proposes an extended calibration approach for improving Omnidirectional Mobile Robot (OMR) motion response in the context of mechanical build imperfections (misalignment). A precise indoor positioning system is required to obtain accurate data for calculating the calibration parameters and validating the implementation response. An ultrasound-based commercial solution was considered for tracking the OMR, but the practical observed errors of the readily available position solutions requires special processing of the raw acquired measurements. The approach uses a multilateration technique based on the point-to-point distances measured between the mobile ultrasound beacon and a current subset of fixed (reference) beacons, in order to obtain an improved position estimation characterized by a confidence coefficient. Therefore, the proposed method managed to reduce the motion error by up to seven-times. Reference trajectories were generated, and robot motion response accuracy was evaluated using a Robot Operating System (ROS) node developed in Matlab-Simulink that was wireless interconnected with the other ROS nodes hosted on the robot navigation controller.

Multi-objective scheduling of a single mobile robot based on the grey wolf optimization algorithm

During the last decades, intelligent mobile robots have been recognized as one of the most promising and emerging solutions used for fulfilling material transport demands in intelligent manufacturing systems. One of the most significant characteristics of those demands is their multi-objectivity, where identified objectives might usually conflict. Therefore, obtaining the optimally scheduled robotic-based material transport system that is simultaneously facing several conflicting objectives is a highly challenging task. To address such a challenge, this paper proposes a novel multi-objective Grey Wolf Optimizer (MOGWO) methodology to efficiently schedule material transport systems based on an intelligent single mobile robot. The proposed optimization methodology includes the comprehensive analysis and the mathematical formulation of 13 novel fitness functions combined to form a Pareto front of the multi-objective optimization problem and a novel strategy for optimal exploration of multi-objective search space. Moreover, four metrics, i.e., Generational Distance (GD), Inverted Generational Distance (IGD), Spacing (SP), and Maximum Spread (MS), are employed to quantitively evaluate and compare the effectiveness of the proposed enhanced MOGWO algorithm with three state-of-the-art metaheuristic methods (MOGA, MOAOA, and MOPSO) on 25 benchmark problems. The results achieved through two experimental scenarios indicate that the enhanced MOGWO algorithm outperforms other algorithms in terms of convergence, coverage, and the robust optimal Pareto solution. Finally, transportation paths based on obtained scheduling plans are experimentally corroborated by the mobile robot RAICO (Robot with Artificial Intelligence based Cognition) within a physical model of the intelligent manufacturing environment. The achieved experimental results successfully demonstrate the efficiency of the proposed methodology for optimal multi-objective scheduling of material transport tasks based on a single mobile robotic system.

Improvement of Strong Tracking UKF-SLAM Approach using Three-position Ultrasonic Detection

As for the uncertainty problem of detection and estimation of robot localization and mapping using ultrasonic sensor, this paper proposes the improvement of Strong Tracking UKF-SLAM approach using three-position ultrasonic detection. A three-position ultrasonic detection model is first of all built for reducing these uncertainties through topological relationship screening and environmental contour estimation. Then Strong Tracking UKF-SLAM approach is improved by using multiple fade factors to fuse the ultrasonic measurement data and motion model information of robot for obtaining more accurate localization and mapping. Finally, we construct simulation and indoor experimental environments and design the mobile robot system with ultrasonic sensor for verification. The simulation represents that the improved algorithm has less error and more accurate effect than original algorithms in localization and mapping of mobile robot. The indoor environmental experiment is performed for illustrating the feasibility and effectiveness of the proposed method. The proposed method has certain reference value for research of Simultaneous Localization and Mapping.