Dynamics Of Mobile Robot Research Articles

Exact linearization and control of a mobile robot for the inspection of soil resources in Solanum tuberosum crops.

In recent years, the development of robots for agro-industrial applications, such as the cultivation of Solanum tuberosum potatoes, has aroused the interest of the academic and scientific communities. This is due, at least in part, to the complexity of modeling and robustly controlling some dynamics inherent to nonlinear behaviors normally attributed to the different technologies associated with the movement of these autonomous vehicles and their non-holonomic constraints. The different nonlinear dynamics of mobile robots are usually represented by state-space models. However, given some equilibrium and stability characteristics, the implementation of effective controllers for the robust parametric tracking and variation problem requires techniques that allow the operability of robots around regions of stable equilibrium. Feedback linearization control is one such technique that attempts to mathematically eliminate nonlinear expressions from the plant model. However, this technique requires an observable and controllable mathematical model. If there is some relationship between the model inputs and a controlled output that allows the relative degree of the control law to be determined, the controller design and implementation are posed as a linear issue. Flat filters developed from the generalized proportional integral control approach are an alternative that could facilitate the design of controllers for these linearized systems. From these flat filters, it is possible to obtain the transfer function of a controller without relying on the derivatives of the system output. This work proposes the design of a controller via exact linearization and its equivalent flat filter for a robot inspector of the soil resource of S. tuberosum crops in the department of Cundinamarca, Colombia. The actuator motion constraints resulted in a robot with two degrees of mobility and one non-holonomic constraint. Numerical validation of this system suggests that it can be an effective solution to the problem of tracking control at changing references by providing a system capable of navigating through crop rows. The results suggest correct tracking for linear and circular trajectories. However, the control lacks the ability to track spiral-type trajectories.

Second-order-optimal filtering on SE(2)×R2 for the Chaplygin sleigh

In the last decades many filters have been proposed to solve the problem of pose estimation that naturally arises in robotics, both for manipulators and mobile robots. The dynamics of mobile robots can be mathematically described by exploiting the theory of Lie groups embedding holonomic and nonholonomic constraints. In this paper we design a second-order-optimal filter for the so-called Chaplygin sleigh, that is a mechanical system with a nonholonomic constraint. In particular we examine the importance to know the exact dynamic equations, and to exploit the underline Lie group structure of the system. Moreover, we investigate the conditions that ensure the preservation of the nonholonomic constraint by properly choosing the affine connection which guarantees that the orthogonal velocity is equal to zero. In this work the sensing system consists of a GPS-like configuration (Global Positioning System) obtained by using two antennas attached to the planar rigid body and an INS-like unit (Inertial Navigation System) to measure the velocities.

Dynamics of mobile robot equipped with inertial vibration exciter and unidirectionally rotating wheels

Vibration-driven locomotion principles are currently of significant interest among designers and researchers dealing with mobile robotics. Among a great variety of robots chasses, the wheeled ones are most commonly used. The major purpose of this study consists in defining the dynamic characteristics of the wheeled vibration-driven robot equipped with the centrifugal (inertial) vibration exciter (unbalanced rotor) and overrunning clutches ensuring the robot’s wheels rotation in one direction. The research methodology is divided into three basic stages: developing the robot’s dynamic diagram and deriving the motion equations followed by numerical modelling in the Mathematica software; designing the 3D-model and simulating the robot motion in the SolidWorks software; creating the experimental prototype and conducting the full-scale tests. The obtained results show the time dependencies of the robot’s body acceleration, speed, and displacement at certain operational conditions. The main scientific novelty of the paper resides in substantiating the relationships between the robot’s design parameters and its dynamic characteristics under different operational conditions. The performed investigations can be useful for researchers and designers dealing with the vibration-driven robots, capsule-type locomotion systems, pipelines inspecting vehicles, etc.

ПАРАМЕТРИЧЕСКИЙ СИНТЕЗ СИСТЕМЫ УПРАВЛЕНИЯ ГРУППОВЫМ ДВИЖЕНИЕМ РОБОТОВ С ИСПОЛЬЗОВАНИЕМ СТАТИСТИЧЕСКОГО ИМИТАЦИОННОГО МОДЕЛИРОВАНИЯ

The article proposes a parametric synthesis method of a multi-robot formation controller.The movement of the fo m tion i c ied out on the oute et by hum n ope to . Robot’ controlsystem corresponds to the modular-assembly principle based on common software, the jointfunctioning of which is implemented by middleware, for example, Robot Operating System. Errors inthe mobile robot control system are caused by: probabilistic application conditions, data-measuringsystem random errors, using simplified dynamic model within the development process. The influenceof the operating conditions on the communication system and the mobile robot autonomous drivingsystem performance reflects by the probabilistic-temporal characteristics: communications and informationsystem delay and the inten ity of mobi e obot’ top . method of t ti tic imu tionmodeling allowed taking into account the probabilistic-temporal characteristics of the mobile robotcommunication and the autonomous driving systems, as well as mobile robot dynamics. The coordinatedmovement of the multi-robot formation along a given path is provided by the method of a decentralizedvirtual structure. The task execution quality is evaluated by two indicators: the deviationof the form from the given one and the task-performance time. As an example, we consider the task ofthe movement of three robots along the route in a row-shaped formation, in which, for a given probabilistic-temporal characteristics, a multi-robot formation accomplish the given task in the shortesttime with minimal deviations of formation shape from the given one. Optimization solution allowedus to determine the optimal parameter of the formation control system. The optimization problem wassolved using the golden section method, statistical simulation was performed using MATLAB Simulinkand Parallel Computing Toolbox packages. A simulation of a homogeneous group of threemobile robots movement was performed for the task of driving along the route in the row-shapedformation with an interval of 5 m and a desired speed of 3 m/s. The quality of the autonomous drivingsystem ensures accident-free motion with an intensity of 1,2 stops per minute. The communicationsand information system with fully connected network topology provides communications flow betweenmobile robots with a frequency of no more than 10 Hz. Communications system delay vary inthe range from 0.1 to 0.5 s.

Dynamics of mobile robots based on the principle of least Gauss coordination taking into account random disturbing forces

In this paper, the derivation of the equations of dynamics of a four-wheeled mobile robot is carried out using the variational principle of least constraint, known as the Gauss principle. Equations of nonholonomic constraints are obtained. The function of the measure of coercion of the four-wheeled mobile robot is composed. Dynamic equations based on the Gauss principle are obtained taking into account the dynamic characteristics of two DC motors. Methods for taking into account the friction forces on the wheels and random perturbations due to the unevenness of the canvas are proposed. On the Maple platform, an algorithm and a program for modeling the dynamics of a mobile robot based on the Gauss principle were developed the correctness of the obtained equations of robot motion were proved.

Robot Navigation in Complex Workspaces Using Conformal Navigation Transformations

Navigation functions provide both path and motion planning, which can be used to ensure obstacle avoidance and convergence in the sphere world. When dealing with complex and realistic scenarios, constructing a transformation to the sphere world is essential and, at the same time, challenging. This work proposes a novel transformation termed the conformal navigation transformation to achieve collision-free navigation of a robot in a workspace populated with obstacles of arbitrary shape. The properties of the conformal navigation transformation, including uniqueness, invariance of navigation properties, and no angular deformation, are investigated, which contribute to the solution of the robot navigation problem in complex environments. Based on navigation functions and the proposed transformations, feedback controllers are derived for the automatic guidance and motion control of kinematic and dynamic mobile robots. Moreover, an iterative method is proposed to construct the conformal navigation transformation in a multiply-connected workspace, which transforms the multiply-connected problem into multiple simply connected problems to achieve fast convergence. In addition to the analytic guarantees, simulation studies verify the effectiveness of the proposed methodology in workspaces with non-trivial obstacles.

Derivation and analysis of the dynamic equations of mobile robots with random disturbing forces based on the principle of least gauss force

In this paper, the derivation of the equations of dynamics of a four-wheeled mobile robot is carried out using the variational principle of least constraint, known as the Gauss principle. Equations of nonholonomic constraints are obtained. The function of the measure of coercion of the four-wheeled mobile robot is composed. Dynamic equations based on the Gauss principle are obtained taking into account the dynamic characteristics of two DC motors. Methods for taking into account the friction forces on the wheels and random perturbations due to the unevenness of the canvas are proposed. On the Maple platform, an algorithm and a program for modeling the dynamics of a mobile robot based on the Gauss principle were developed the correctness of the obtained equations of robot motion were proved.

Construction of a mathematical model of the dynamics of an autonomous mobile robot of variable configuration

This paper considers the construction of a mathematical model of the movement of an autonomous mobile robot (AMR) in variable configuration, taking into account the relationship of the dynamic parameters of a mechanical system. As an example, the design of AMR with a manipulator is considered. The object of this study is the dynamics of AMR with a manipulator. The peculiarities of the dynamics of AMR with the manipulator are due to the change in the position of the center of mass of the system with the relative movement of the manipulator and the commensurate non-diagonal and diagonal elements of the inertia tensor calculated relative to the axes of the base coordinate system. The construction of the mathematical model was carried out according to the Nyton-Euler method. The resulting mathematical model contains: – an equation of motion of the center of mass of the AMR system of variable configuration along the trajectory in the inertial coordinate system; – an equation of angular motion of AMR in variable configuration in the inertial coordinate system; – an equation of motion of the manipulator with respect to AMR. In a general case, the center of mass of the AMR platform moves in a horizontal plane. Establishing the relationship of dynamic parameters of the mechanical system will make it possible to maintain functionality and ensure the orientation of AMR in vertical planes despite the movement of the manipulator. As an object of control, AMR with a manipulator is a multi-connected system with a cross-internal connection of control channels, which is formed by the dynamic parameters of a mechanical system. Based on the results of mathematical modeling using the proposed model, it is possible to develop algorithms for adaptive control using cross-connection of channels. This will make it possible to identify reserves to reduce energy consumption, increase stability, improve the efficiency and survivability of AMR in variable configuration during autonomous work under extreme conditions.

Analysing dynamics of two-wheel mobile robot for real-time development of chatbot

Analysing dynamics of two-wheel mobile robot for real-time development of chatbot

Analysing dynamics of two-wheel mobile robot for real-time development of chatbot

Analysing dynamics of two-wheel mobile robot for real-time development of chatbot

Fuzzy Synergetic Control for Dynamic Car-Like Mobile Robot

Abstract This paper aims to present the dynamic control of a Car-like Mobile Robot (CLMR) using Synergetic Control (SC). The SC control is used to make the linear velocity and steering velocity converge to references. Lyapunov synthesis is adopted to assure controlled system stability. To find the optimised parameters of the SC, the grey wolf optimiser (GWO) algorithm is used. These parameters depend on the best-selected fitness function. Four fitness functions are selected for this purpose, which is based on the integral of the error square (ISE), the integral of the square of the time-weighted error (ITSE), the integral of the error absolute (IAE) and the integral of the absolute of the time-weighted error (TIAE) criterion. To go further in the investigation, fuzzy logic type 2 is used to get at each iteration the appropriate controller parameters that give the best performances and robustness. Simulations results are conducted to show the feasibility and efficiency of the proposed control methods.

Method of analysis of the current state of inertial characteristics of an autonomous mobile robot of variable configuration

The features of the dynamics of an autonomous mobile robot (AMR) of variable configuration with the relative movement of attachments are considered. Analysis of the current state of inertial characteristics during AMR operation will ensure stable movement along a given trajectory, successful implementation of technological operations by attachments, and preservation of the robot's functionality when operating under undetermined or extreme conditions. At the design stage, the analysis of the inertial characteristics of the AMR will make it possible to refine the parameters of the mathematical model, improve the algorithms for adaptive control and correct the commands for the actuators. Figs.: 2. Tabl.: 2. Bibliogr.: 10 titles.
 Keywords: autonomous mobile robot, inertial characteristics.

How to use the Omni-Wrist III for dexterous motion: An exposition of the forward and inverse kinematic relationships

The Omni-Wrist III, invented by Ross-Hime Designs, Inc. (Rosheim, 1999, 2002), is a well known two-degree of freedom wrist mechanism that incorporates parallel links with double universal joints (N-UU). It has the advantage of singularity-free operation over the entire hemispherical work-space and maintains a constant axial distance between the two joints. These characteristics make it an appealing choice for mobile robotic appendages that require dexterous maneuvers. While the two active input joint angles are coupled, this paper presents an accessible exposition of the forward and inverse kinematics for the position and velocity of the mechanism. The novelty of this analysis lies in the parameterization of the kinematics in terms of the vector between the origins of the tool and space frames. The results of this paper provide concise equations that are readily implementable in simulation and on low power microcontrollers enabling the use of the Omni-Wrist III for highly dynamic mobile robot maneuvers.

Research on Mechanical Design of Multi Motion Dynamic Reconfigurable Wheel Shoe Compound Robot

In some complex and changeable outdoor terrain survey, the work that may not be realized by manpower is mostly replaced by robots or unmanned machines. Based on the motion advantages of wheeled and tracked mobile mechanisms, a wheel shoe compound robot with diversified motion modes is developed.The robot is composed of control unit, two identical reconfigurable wheels, turnover mechanism and vehicle body, so it has the advantages of three modes. Based on the relevant motion mechanics, the relevant parameters are optimized to continuously promote the continuous change of motion trajectory and the continuous optimization of drive motor performance, which plays a positive role in improving motor efficiency. Through experimental research, it is found that this multi mobile dynamic mobile robot can continuously adjust its own mechanism, move freely in the complex and changeable outdoor environment, and has strong environmental adaptability, which shows the effectiveness of the design.

Method of synthesis of optimal grip trajectories of a manipulator of an autonomous mobile robot

The features of the dynamics of an autonomous mobile robot of variable configuration with a relative motion of the manipulator are considered.
 To effectively perform technological operations by the AMR manipulator in extreme previously unknown conditions, it is advisable at the design stage to develop a database containing the optimal sequences of movements along generalized coordinates that ensure the movement of the gripper between the given initial and final points of the working space. Figs.: 3. Tabl.: 2. Refs.: 20 titles.

Trajectory tracking of nonholonomic mobile robots by geometric control on special Euclidean group

AbstractThis article studies the trajectory tracking of nonholonomic mobile robots by using geometric control methods, with extension to consensus tracking and formation tracking. Different from the system model given in the Euclidean space, we establish the dynamics of mobile robots on the tangent bundle of the Lie group, which is a global and unique description independent of local coordinates. Firstly, the tracking control of one leader with one follower is considered, which is converted to the stabilization of two relative subsystems by designing an adjoint system. Then, the controller is extended to consensus tracking of multiple robots connected by a directed acyclic graph, where the convex combination on nonlinear manifolds is introduced to construct a virtual leader for each follower. Next, the relation between consensus control and formation control is established, and a new transformed system is constructed so as to derive the formation tracking controller from the consensus result. Finally, simulation examples are presented to verify the effectiveness of the proposed controllers.

Modeling the dynamics of an autonomous mobile robot with a manipulator

The features of the dynamics of an autonomous mobile robot of variable configuration with a relative motion of the manipulator are considered. Based on the results of mathematical modeling the dynamics of the robot, taking into account the off-diagonality of the tensor of inertia, it is possible to estimate the cross-connection of the control channels and determine the presence of angular moments in the planes perpendicular to the direction of movement of the autonomous mobile robot. Figs.: 3. Table: 3. Bibliography: 11 titles.Keywords: autonomous mobile robot; manipulator; dynamics; mathematical modeling.

Distributed approximation-free design for ensuring network connectivity of uncertain nonholonomic multi-robot synchronized tracking systems with disturbances

A distributed approximation-free design for maintaining initial connectivity of uncertain nonholonomic multi-robot synchronized tracking systems is developed under limited communication ranges where the models of followers are regarded as the kinematics and dynamics of uncertain nonholonomic mobile robots. All nonlinearities and external disturbances in the followers’ dynamics are assumed to be unknown. The primary improvement in the current development is that local trackers for ensuring connectivity among robots are designed by using only relative posture errors and adaptive function approximators such as neural networks or fuzzy logic systems are not utilized despite unknown nonlinearities in the robot dynamics. This improvement has been done by transforming individual linear position errors among mobile robots to individual nonlinear position errors using connectivity-preserving functions with communication ranges. The predefined synchronized tracking performance and the guaranteed connectivity of the overall closed-loop system are proved via the Lyapunov stability theorem.

Neural networks and behaviour based control for education botanical robot navigation

The development of robots began when the military needed it as war equipment, and then it was used by some industries to develop production until now widely used for education and agriculture. Educational robots are usually more universal and simpler than industrial or military robots because robots for education are made only for simulations or prototypes. In this study, the authors surveyed prototypes of Educational botany robots, namely robots used to distinguish fruit maturity. In this journal, the behaviour-based control (BBC) algorithm will continue implemented into mobile robots. The movement of the mobile robot prepared in advance, and then actually the mobile robot is wheeled compared to the desired path. Besides, both kinematic and dynamic smelling mobile robots are derived and considered. In this study, only focused on mobile robots three-wheel differential drive, which will explore in a circular and straight path. In this journal, it can be found that image processing techniques can be used to determine the maturity of watermelons which are shown in different average values in each image obtained by the camera. The best models are generated by layer 32 hidden with an accuracy value of 87% at the training dataset level 60:10:30. The Behaviour Based Control Method has directional movements. But there was an error in each test so that I couldn’t take the watermelon correctly. The error rate reaches 25% from 40 tests or about ten failures in the form of deviating from the object point.

Optimal Control of Sweeping Processes in Robotics and Traffic Flow Models

The paper is mostly devoted to applications of a novel optimal control theory for perturbed sweeping/Moreau processes to two practical dynamical models. The first model addresses mobile robot dynamics with obstacles, and the second one concerns control and optimization of traffic flows. Describing these models as controlled sweeping processes with pointwise/hard control and state constraints and applying new necessary optimality conditions for such systems allow us to develop efficient procedures to solve naturally formulated optimal control problems for the models under consideration and completely calculate optimal solutions in particular situations.