Mobile Robot Control System Research Articles

Long-term operation of a remote control system for mobile robots using a smartphone application by any user

Long-term operation of a remote control system for mobile robots using a smartphone application by any user

Algorithmic support of an adaptive control system for an autonomous mobile robot

Algorithmic support of an adaptive control system for an autonomous mobile robot

Optimization of the PID coefficients for the line-follower mobile robot controller employing genetic algorithm

O b j e c t i v e s. To develop a control system for the movement of a mobile robot along a color-contrast line, as well as to find the values of the coefficients of a proportional-integral-differentiating (PID) controller that allows the robot to move along the line at a given speed.M e t ho d s. To adjust the values of the coefficients of the PID controller, methods of enumeration, automatic tuning and a genetic algorithm are used.Re s u l t s. A software package for tuning the PID controller of the educational mobile robot RoboCake, designed to move along a closed color-contrast line at a given speed, has been developed. The software package consists of a simulation model of the specified robot in the Simulink environment, several virtual traces-polygons and a specialized solver based on the developed genetic algorithm. With the help of the proposed fitness function, a mobile robot control system that satisfies the stated conditions is implemented. Based on the conducted model experiments, the desired values of the parameters of the PID controller are obtained.Co n c l u s i o n. A comparison of the effectiveness of various methods of tuning the PID controller is carried out. The developed software package is designed to solve the practical problem of moving a mobile robot along a color-contrast line at a speed of 1 m/s. The results obtained can be used to study methods of evolutionary tuning of stabilization systems for transport robots, ensuring their movement without overshoot.

Development of a Design Methodology for Cloud Distributed Control Systems of Mobile Robots

This article addresses the problem of cloud distributed control systems development for mobile robots. The authors emphasize the lack of a design methodology to guide the process of the development in accordance with specific technical and economic requirements for the robot. On the analysis of various robots architectures, the set of the nine most significant parameters are identified to direct the development stage by stage. Based on those parameters, the design methodology is proposed to build a scalable three-level cloud distributed control system for a robot. The application of the methodology is demonstrated on the example of AnyWalker open source robotics platform. The developed methodology is also applied to two other walking robots illustrated in the article.

A one decade survey of autonomous mobile robot systems

<span lang="EN-US">Recently, autonomous mobile robots have gained popularity in the modern world due to their relevance technology and application in real world situations. The global market for mobile robots will grow significantly over the next 20 years. Autonomous mobile robots are found in many fields including institutions, industry, business, hospitals, agriculture as well as private households for the purpose of improving day-to-day activities and services. The development of technology has increased in the requirements for mobile robots because of the services and tasks provided by them, like rescue and research operations, surveillance, carry heavy objects and so on. Researchers have conducted many works on the importance of robots, their uses, and problems. This article aims to analyze the control system of mobile robots and the way robots have the ability of moving in real-world to achieve their goals. It should be noted that there are several technological directions in a mobile robot industry. It must be observed and integrated so that the robot functions properly: Navigation systems, localization systems, detection systems (sensors) along with motion and kinematics and dynamics systems. All such systems should be united through a control unit; thus, the mission or work of mobile robots are conducted with reliability.</span>

HARDWARE AND SOFTWARE COMPLEX FOR CREATION AND RESEARCH OF LOCOMOTION AND AUTONOMOUS MOTION CONTROL SYSTEMS FOR MOBILE ROBOTS

A software and hardware complex for creation and research of control systems for mobile robots with walking and wheeled movers is presented. The synthesis of control laws is performed by the inverse problem method; Methods for connecting various SLAM algorithms, including those using data from computer vision devices, are considered.

Inspection Mobile Robot’s Control System with Remote IoT-based Data Transmission

The article presents the main stages of the development of remote control system for the inspection mobile robot operating on inclined ferromagnetic surfaces. The mobile robot remains on the surface and moves along working areas using separate clamping permanent magnets and caterpillars. The focus is on the control system’s architecture and remote data transmission based on Internet of Things technologies. Features of non-expensive Arduino Uno and WeMos D1 R2 mini microcontrolled development boards, cloud service Blynk, as well as multi-tab Android application interactions are revealed at the inspection mobile robot movement on the inclined surface. Experimental results of the proposed system show a good compatibility of chosen hardware, user-friendly human-machine interface and high mobility for future research of modern control algorithms at Internet of Things approach implementation for the extreme robotics.

Development of a control system for a mobile robot based on Markov processes

The purpose of this work is to develop and study a control system for mobile robots based on Markov processes. The paper investigates the adequacy of the control system algorithms based on Markov processes as applied to a mobile tracked robot.

Speed control system in mobile robot based on Bezier curve trajectory

The development of robot technology is currently growing rapidly. Mobile robot is one robot with many applications in everyday life. One of the important things in the field of mobile robots is the problem of trajectories or trajectories, in this case how robots can track approved paths. In this study, the mobile robot control system has been tested to track tracks. The path used in this study is the third-order Bezier Order, with control points and end points of the predetermined pathway. Based on the results of simulation tests on the development of mobile robot trajectories, based on the results of simulation tests on mobile robots, it is found that the performance of the track tracking control system is very dependent on the placement of the Bezier curve control points or in other words the actual path formed by the robot is greatly influenced by the shape of the Bezier trajectory that was designed.

INFORMATION TECHNOLOGY FOR SYNTHESIS AND OPTIMIZATION OF FUZZY SYSTEMS RULE BASES

In the last two decades, intelligent computer systems based on fuzzy set theory, fuzzy logic and soft computing are widely used in various fields of science and technology to solve problems of control, identification, modeling of complex physical and economic phenomena, classification, pattern recognition, etc. Modern research in the field of creation and development of fuzzy systems (FS) of control and decision-making is conducted mainly in the direction of development of highly effective methods and information technologies of their synthesis and structural-parametric optimization. This paper is devoted to the development and research of information technology for the synthesis and optimization of highly efficient rule bases (RB) with the optimal set of consequences and optimal number of rules for Mamdani-type FSs in terms of incomplete source information. The developed information technology allows to conduct iterative search of the optimal vector of RB consequences based on a sequential search of the consequences of each rule, as well as to identify and exclude rules from RB, that do not affect the system operation, to reduce the total number of rules to optimal. To study the effectiveness of the proposed information technology in this work, the synthesis and optimization of the fuzzy automatic control system (ACS) for the multi-purpose mobile robot (MR), which is able to move on inclined and vertical ferromagnetic surfaces, is carried out. The obtained results of computer simulation showed that the fuzzy ACS of MR with optimized RB based on the developed information technology has higher quality indicators of control compared to the ACS with a similar RB developed on the basis of experts knowledge. Also, the optimized RB by means of the proposed information technology has fewer rules than the full RB, which is synthesized on the basis of experts knowledge, which, in turn, significantly simplifies the further software and hardware implementation of the developed fuzzy ACS of MR. In addition, in the process of synthesis and optimization of the RB for the fuzzy ACS of MR, presented information technology did not require significant computational costs, which generally confirms its high efficiency and feasibility of application to design rule bases of control and decision making FSs of different types.

Nonlinear control of electric drive system of four-wheel mobile robot with two differential drive units

This paper contains a solution to the problem of constructing an electric drive control system of a four-wheel mobile robot with two differential drive units. During the synthesis of this system, the asymmetry of the drive units’ location was taken into account. This makes it possible to take into account various robot designs. The finished system can be scaled to stabilize the contour movement of mobile robots with more than two rotary blocks. In conclusion, the results of numerical simulations of the control system for various configurations of the wheeled robot are demonstrated.

Experimental validation of integrated and robust control system for mobile robots

The need to design a robust, accurate and lightweight real-time control architecture for a low-cost embedded system has become a necessary step in robotics applications. Therefore, the goal of this work is to design an integrated and accurate control system for a differential wheeled mobile robot. A hierarchical control approach has been adopted in this work which, takes into account the sub-systems controller of the problem related to robot path tracking. To this end, the control structure includes the design of a sliding mode control (SMC) scheme to stabilize the robot and precisely track the path that matches the kinematics of the mechanical structure. Moreover, the control structure provides a new design of the DC motor controller for optimum performance. To obtain an integrated control system for automated tasks, an accurate position estimation and an optimized high-level path planning algorithm have been proposed. The robustness and performance of the approved control and estimation systems have been verified through real-time implementations in different experiments. The results show the high accuracy of the robot’s tracking on different paths.

A method for planning the trajectory of a mobile robot in an unknown environment with obstacles

The known algorithms for planning the trajectory of movement of mobile robots in an unknown environment have high computational complexity or do not allow finding the trajectory that is optimal along the length of the path, while maintaining a safe distance from obstacles. The aim of the work is to increase the efficiency of solving the problem of planning the trajectory of movement of mobile robots from the initial position to the final position in an unknown environment with obstacles, taking into account the limited capabilities (sensory and computational) of mobile robots. The solution to this problem was carried out on the basis of step-by-step optimization of the current position of the robot relative to a given target. The proposed method analyzes the possibility of a robot moving in directions determined by means of analytical geometry based on measurements of on-board distance sensors. An element of scientific novelty is the procedure for calculating trajectory segments based on the choice of an intermediate state and correcting the trajectory taking into account the measurements of the on-board distance sensors of the mobile robot. The proposed method makes it possible to search for the trajectory of a mobile robot in an unknown environment while ensuring a given distance to obstacles. The use of the presented algorithm allows the robot to maintain a high efficiency of the task while functioning in conditions of information deficiency. The reliability of the results was confirmed in the course of software simulation. The solution of the problem, taking into account these features, made it possible to reduce the computational complexity of the method, as well as to remove restrictions on the use of trajectory planning algorithms for mobile robots with low-performance on-board sensors and computing devices. The presented algorithm is implemented in the form of software in the Python programming language, which can be used to simulate autonomous control systems for mobile robots.

Analysis of separate channels in a multi-connected control system

The object of research is the control system of an autonomous mobile robot equipped with an anthropomorphic manipulator with four degrees of mobility. When a mobile robot of variable configuration moves along a given route, the control system must ensure a minimum deviation of the center of mass of the platform from a given trajectory. In this case, the control moments are directed along the axes of the coordinate system associated with the platform of the autonomous mobile robot. With relative movements of the manipulator, the tensor of inertia of the system of bodies in the coordinate system associated with the platform becomes off-diagonal and non-stationary, which determines the interconnection of control channels. The number of control actions: when moving the trajectory – four (for each wheel), when the manipulator is working – four (for each generalized coordinate). Thus, the control system is multidimensional, the connection between control channels is carried out due to the physical properties of the control object.The paper presents the results of the first stages of the development of a multi-connected control system: study of separate control channels, synthesis of a separate controller, adjustments of the controller and analysis of the quality of the created control system. The research is carried out using matrix transfer functions; Besekersky formulas are applied to determine the parameters of the desired transfer function. During the analysis, logarithmic and amplitude frequency characteristics were constructed for each separate channel, a block diagram was chosen, and a transfer function was compiled. The quality assessment of the synthesized separate channel is carried out according to the following criteria: accuracy, speed, oscillation, transient time, overshoot, amplitude and phase distortions, stability margins. The properties of the synthesized separate channel in terms of accuracy, speed and oscillation correspond to the conditions.Further research and synthesis of multi-connected control systems of a mobile robot with a manipulator will increase its survivability and efficiency in autonomous operation. Since a mobile robot with a manipulator is an example of an «autonomous mobile robot of variable configuration» object class, the results obtained can be applied to all objects of this class.

Поиск оптимальных функций принадлежности нечетких систем на основе биоинспирированных эволюционных алгоритмов. Часть 2. Реализация метода и исследование его эффективности

Исследована эффективность метода поиска оптимальных функций принадлежности нечетких систем на основе биоинспирированных эволюционных алгоритмов глобальной оптимизации. Предложенный метод позволяет находить оптимальные функции принадлежности лингвистических термов при решении компромиссной задачи минимизации целевой функции и уменьшения вычислительных затрат в процессе дальнейшей параметрической оптимизации нечетких систем. Для исследования эффективности рассматриваемого метода проведен поиск оптимальных функций принадлежности для нечеткого регулятора системы управления многоцелевым мобильным роботом, предназначенный для перемещения по наклонным и вертикальным ферромагнитным поверхностям, с реализацией данного метода на основе трех биоинспирированных эволюционных алгоритмов: , искусственных иммунных систем, биогеографический Анализ полученных результатов компьютерного моделирования показал, что применение предложенного метода поиска оптимальных функций принадлежности позволяет существенно повысить эффективность управления мобильным роботом, а также уменьшить общее количество параметров при последующей параметрической оптимизации лингвистических термов, что подтверждает высокую эффективность разработанного метода. .

Investigation of the Operation of the Extended Kalman Filter Supplemented by an Adaptive Digital Filter for Integrating Data from a Mobile Robot Control System

Purpose of reseach. The article deals with the study of the operation of the extended Kalman filter (EKF), supplemented with an adaptive digital filter in order to compensate for the error in the operation of the EKF when performing data integration of the mobile robot control system.Methods. The adaptive digital filter (ADF) is a self-tuning filter that iteratively changes its variable parameters to achieve the optimal desired values of the output data. The EKF supplemented with the ADF with the NLMS adaptation algorithm will be called the EKF–ADF system or the EKF+NLMS digital filter. An important task is the selection of the number of frames and ADF weighting coefficients at which the optimum quality of noise suppression and the convergence rate of the adaptation algorithm are achieved.Results. With various options of organizing the operation of the ADF buffer memory, the adjusted values for assessing the state of the ‘mobile robot–environment’ system may differ. When the number of input data frames and ADF weighting coefficients are small, low quality noise suppression will be observed. With an increase in the number of frames and weighting coefficients, the quality of noise suppression is improved, and the convergence rate of the adaptation algorithm decreases.Conclusion. The EKF+NLMS digital filter algorithm takes an intermediate place between the EKF algorithm and the serial filtering of the EKF and ADF signals with the NLMS algorithm according to the criteria for estimating the mean square error, mean absolute error, signal-to-noise ratio, and convergence rate.

Engineering Software for a Mobile Robot Motion Control System

The paper centres round the problem of the engineering a motion control system for a mobile robot based on the effective selection of software components with respect to the numerical criterion proposed by the authors. The data for the selection process comes out the reproducible experiments with the sets of alternative components in a Gazebo virtual infrastructure simulating the real robot operating conditions. The genetic algorithm is used to reduce the number of experiments with unpromising sets of software components. The methodology proposed by the authors is applied to the real task of engineering a motion control system for a non-anthropomorphic mobile robot. The virtual infrastructure and genetic algorithm parameters are provided as well as the physical model of the robot for that task. To calculate the integral quality criterion proposed in the paper, 4 partial quality criteria were measured in the experiments with different software components. The motion process of the physical robot with the selected software components is shown.

РЕАЛІЗАЦІЙНА МОДЕЛЬ АДАПТИВНОГО СУМАТОРА ДЛЯ НЕЙРОПОДІБНИХ ЕЛЕМЕНТІВ

One of the promising areas for the use of neurotechnologies is robotics, namely, systems of technical vision and control systems for mobile robots of various applications. In particular, one of the basic tasks for these systems as part of autonomous robots is the task of object recognizing and determining of the obstacles contours in the movement of mobile robots in a non-deterministic environment. For a compact and reliable implementation of the basic units of these systems, there is no alternative) the use of neural network technologies with to focusing on perspective modern tools (FPGA). It is necessary to take into account the simultaneous perception of visual information, which requires, in turn, parallel spatially distributed processing of large amounts of information. The work proposes the structure of the adaptive adder in composition of artificial neurons, which are basic neural-like elements of different types of neural networks. The proposed pipeline summing device has advanced functionality, as it simulates the operation of the adaptive adder in the formal neuron with the formation of the result of processing taking into account the external bias with the sign, and also performs parallel summation of vector array numbers with the formation of their sum. The proposed adaptive adder has a regular structure consisting of (n+1) cells with almost the same set of units and connections between them, and also implements a spatially distributed process of parallel processing over n input elements of the vector array. All this simplifies the process of placing the adaptive adder in the FPGA chip. The orientation on functionally and technologically powerful FPGA chips allows to get compact and full-featured neurostructures for various purposes, the need for which is extremely important in the control systems of mobile robots.

РАСШИРЕННЫЙ ФИЛЬТР КАЛМАНА, ДОПОЛНЕННЫЙ АДАПТИВНЫМ ЦИФРОВЫМ ФИЛЬТРОМ, ДЛЯ КОМПЛЕКСИРОВАНИЯ ДАННЫХ СИСТЕМЫ УПРАВЛЕНИЯ МОБИЛЬНЫМ РОБОТОМ

The paper proposes the combination of the extended Kalman filter and an adaptive digital filter to compensate an operational error of the extended Kalman filter during data fusion of a mobile robot control system. The paper describes the structure and operation of such combination, shows the buffer memory configuration of an adaptive digital filter.

Trajectory Generation of a Two-Wheeled Mobile Robot in an Uncertain Environment

This article presents a novel method to generate a trajectory for a two-wheeled mobile robot moving in an uncertain environment where only a few way-points are available to reach a nearby target state. The proposed method interpolates way-points by the combination of a straight line and a fifth-order Bézier curve along which the curvature varies continuously. In addition, a method to generate the associated timing law is proposed such that the robot travels along the curve in near minimum time under the maximum velocity and torque constraints. Since the method aims for an online application, heuristic techniques are applied to minimize the computational cost for finding the optimal solution. The time for computing a complete time-optimal trajectory for a moving robot to transit to a next way-point is only several milliseconds when tested in a personal computer. This result implies that a highly efficient motion control system for a two-wheeled mobile robot can be implemented with a low-cost hardware available today.