Dynamics Of Mobile Robot Research Articles

Wheeled Mobile Robot Tracking Control without Velocity Measurement

In this paper, a new robust trajectory tracking control scheme for wheeled mobile robots without velocity measurement is proposed. In the proposed controller, the velocity observer is used to estimate the velocity of wheeled mobile robot. The dynamics of wheeled mobile robot is considered to develop the controller. The proposed controller has the following features: i) The proposed controller has good robustness performance; ii) It is easy to improve tracking performance by setting only one design parameters.

Formation tracking control for a class of multiple mobile robots in the presence of unknown skidding and slipping

This study investigates the formation control problem for a class of multiple mobile robots considering unknown skidding and slipping, and torque saturation. The kinematics and dynamics of multiple mobile robots with skidding and slipping effects are considered. The proposed formation control scheme is derived from the dynamic surface design and virtual structure approach where the reference trajectories consisting of path parameters are employed to satisfy both the tracking control and the formation maintenance. The adaptive technique is used to compensate the unknown skidding and slipping effects. From Lyapunov-stability analysis, we prove regardless of unknown skidding and slipping that all signals of the total closed-loop system are semiglobally uniformly ultimately bounded and the point-tracking errors and the synchronisation error for the desired formation converge to an adjustable neighbourhood of the origin. In addition, it is analysed that the orientation error for each robot is related to the speed of the reference trajectory and the skidding effect. The performance and stability of the proposed approach are verified from simulation results.

모터 제어 입력 제한 조건이 고려된 차륜 이동 로봇을 위한 효율적인 최소 시간 코너링(Cornering) 주행 계획

We propose an efficient minimum-time cornering motion planning algorithms for differential-driven wheeled mobile robots with motor control input constraint, under piecewise constant control input sections. First, we established mobile robot's kinematics and dynamics including motors, divided the cornering trajectory for collision-free into one translational section, followed by one rotational section with angular acceleration, and finally the other rotational section with angular deceleration. We constructed an efficient motion planning algorithm satisfying the bang-bang principle. Various simulations and experiments reveal the performance of the proposed algorithm.

Dynamic Modelling of Differential-Drive Mobile Robots using Lagrange and Newton-Euler Methodologies: A Unified Framework

This paper presents a unified dynamic modeling framework for differential-drive mobile robots (DDMR). Two formulations for mobile robot dynamics are developed; one is based on Lagrangian mechanics, and the other on Newton-Euler mechanics. Major difficulties experienced when modeling non-holonomic systems in both methods are illustrated and design procedures are outlined. It is shown that the two formulations are mathematically equivalent providing a check on their consistency. The presented work leads to an improved understanding of differentialdrive mobile robot dynamics, which will assist engineering students and researchers in the modeling and design of suitable controllers for DDMR navigation and trajectory tracking.

Fuzzy-logic-assisted interacting multiple model (FLAIMM) for mobile robot localization

Improvement of dead reckoning accuracy is essential for robotic localization systems and has been intensively studied. However, existing solutions cannot provide accurate positioning when a robot suffers from changing dynamics such as wheel slip. In this paper, we propose a fuzzy-logic-assisted interacting multiple model (FLAIMM) framework to detect and compensate for wheel slip. Firstly, two different types of extended Kalman filter (EKF) are designed to consider both no-slip and slip dynamics of mobile robots. Then a fuzzy inference system (FIS) model for slip estimation is constructed using an adaptive neuro-fuzzy inference system (ANFIS). The trained model is utilized along with the two EKFs in the FLAIMM framework. The approach is evaluated using real data sets acquired with a robot driving in an indoor environment. The experimental results show that our approach improves position accuracy and works better in slip detection and compensation compared to the conventional multiple model approach.

Backstepping Control Design on the Dynamics of the Omni-Directional Mobile Robot

The dynamical model of an omni-directional mobile robot is bulit based on the Newtonian mechanics. Correspondingly, a backstepping-based controller is then proposed with proven global stability by selecting a Lyapunov function and introducing a virtual control input for the built dynamical model. Simulation results show the effectiveness of the proposed controller.

Control de Tracción en Robots Móviles con Ruedas

This article presents a solution to improve the performance of wheeled mobile robots that move upon surfaces with small coefficient of static friction. In these circumstances the wheeled mobile robots can experience loss of traction and therefore, slide along the surface. The proposed solution implies the use of a special configuration for the mobile robot, in which all the wheels are driven independently, and a control structure which consists of three distinct parts: firstly, a state-feedback tracking controller based on the kinematic model of the mobile robot is derived. Secondly, an extension of the kinematic control law is made to incorporate the dynamics of the wheeled mobile robot via backstepping. Thirdly, a traction force distribution algorithm that calculates the proper reference signals for each rear wheel is included and the feedback tracking control laws are finally completed. With this solution is possible to control the position and the velocity of the wheeled mobile robot but, at the same time, to distribute the traction force between the wheels in such a way that their sliding is avoided. The effectiveness and usefulness of the designed control algorithms are demonstrated in laboratory experiments using a prototype of the wheeled mobile robot.

Adaptive tracking control for dynamic nonholonomic mobile robots with uncalibrated visual parameters

SUMMARYThe trajectory tracking control problem of uncertain dynamic nonholonomic mobile robots is addressed in this paper. A novel uncertain camera‐object visual servoing kinematic tracking error model is proposed firstly. And then, on the basis of this model, a new adaptive torque tracking controller is presented in the presence of parametric uncertainties associated with the camera system and mechanical dynamic system. The controller synthesis is based on Lyapunov's direct method and backstepping technique. Simulation results are provided to illustrate the performance of the control law. Copyright © 2012 John Wiley & Sons, Ltd.

차륜 이동 로봇의 모터 구동 전압 제한 조건을 고려한 코너링(cornering) 모션의 최소 시간 궤적 계획 및 제어

We propose time-optimal cornering motion trajectory planning and control algorithms for differential wheeled mobile robot with motor actuating voltage constraint, under piecewise constant control input condition. For time-optimal cornering trajectory generation, 1) we considered mobile robot's dynamics including actuator motors, 2) divided the cornering trajectory into one liner section, followed by two cornering section with angular acceleration and deceleration, and finally one liner section, and 3) formulated an efficient trajectory generation algorithm satisfying the bang-bang control principle. Also we proposed an efficient trajectory control algorithm and implemented with an X-bot to prove the performance.

Modeling and motion simulation of a three-wheeled mobile robot with front wheel driven and steered taking into account wheels’ slip

The problem of modeling of dynamics of a three-wheeled mobile robot with front wheel driven and steered is analyzed in this paper. Kinematical structure and kinematics of the robot are described. A universal methodology of analytical modeling of robot’s dynamics is applied. This methodology takes into account wheel-ground contact conditions and wheels’ slip. Its essence is the use of a contact model of deformable tire with rigid ground and division of the robot’s dynamics model into parts connected with wheels, including tire model, and with the mobile platform. The tire model used in this paper results from empirical dependencies determined during investigations of car tires. Ground geometry and type are specified in the environment model. Tire-ground interface is characterized by coefficients of friction and rolling resistance. The robot model takes into account the presence of friction in kinematical pairs. The model of servomotors is included as well. The important part of this work is simulation research performed using Matlab/Simulink package. Simulation research includes solving of the forward and inverse dynamics problems as well as the tracking control task. During simulations, the robot was moving on concrete and on a piece of ice. The simulation research enabled verification of the elaborated solutions.

Dynamic Analysis and Quasi-Sliding Mode Control of Mobile Robot

To avoid the chattering disadvantage of sliding-mode control (SMC), in this paper, a quasi-sliding mode controller is proposed for real-time fine control of a nonholonomic mobile robot. First, the dynamics of mobile robot is analyzed by Lagrangian formula. Then, the quasi-sliding mode controller is used to generate the control torque that drives the mobile robot, such that the linear and angular velocities of the mobile robot follow the desired velocities. At last, computer simulation results confirm the effectives of SMC.

Near-Optimal Tracking Control of a Nonholonomic Mobile Robot with Uncertainties

A combined kinematic/torque control law is developed by using a backstepping design approach for a nonholonomic mobile robot with two driving wheels mounted on the same axis to track a reference trajectory. The auxiliary velocity control inputs are designed for the kinematic steering system to make the posture error asymptotically stable. Next, a computed-torque controller is designed such that the mobile robot's velocities converge on the given velocity inputs in an optimal manner by converting the tracking control problem into the regulation problem whereby the uncertainties in the dynamics of mobile robots are considered. The proposed online and forward-in-time policy iteration (PI) algorithm based on approximate dynamic programming (ADP) is used to solve the optimal control problem with unknown internal dynamics by using single neural networks (NNs) to approximate the cost function. Afterwards, the near-optimal control policy can be computed directly according to the cost function, which removes the action network appearing in the ordinary ADP method. The stability of the dynamical extension system is demonstrated using Lyapunov methods. The simulation results are provided to demonstrate the effectiveness of the proposed approach.

A Model Predictive Navigation Approach Considering Mobile Robot Shape and Dynamics

Most mobile robot navigation approaches assume the robot being point-like or consider only its bounding circle while looking for a collision-free path to a given goal position. A well-known method called the Dynamic Window Approach (DWA) introduced an interesting idea for solving the navigation problem by local optimization in the control space of the robot. Some extensions of the original DWA method can also be found in the literature, which enable its applicability to holonomic and non-holonomic robots and ensure a global and safe solution to the navigation problem. The method described in this paper has also been motivated by the basic idea of dynamic window and contributes to the previous variants by taking the robot shape into consideration as well. A navigation function based model predictive control scheme is utilized to choose the appropriate control for a safe and successful navigation.

Adaptive tracking control for uncertain dynamic nonholonomic mobile robots based on visual servoing

The tracking control of wheeled dynamic mobile robots via visual servoing feedback is considered. A kinematic controller is firstly presented for the kinematic model, and then, an adaptive torque tracking controller is designed for the uncertainty dynamic model in the presence of parametric uncertainty associated with the camera system. The asymptotic convergence of tracking errors to zero is rigorously proved by the Lyapunov method. Simulation results are provided to illustrate the performance of the control law.

Adaptive Stabilization for Uncertain Nonholonomic Dynamic Mobile Robots Based on Visual Servoing Feedback

The stabilization problem of nonholonomic dynamic mobile robots with a fixed (ceiling-mounted) camera is addressed in this paper. First, a camera-object visual servoing kinematic model is introduced by utilizing the pin-hole camera model and a kinematic stabilizing controller is given for the kinematic model. Then, an adaptive sliding mode controller is designed to stabilize uncertain dynamic mobile robot in the presence of parametric uncertainties associated with the camera system. The proposed controller is robust not only to structured uncertainty such as mass variation but also to unstructured one such as disturbances. The stability of the proposed control system and the boundedness of estimated parameters are rigorously proved by Lyapunov method. Simulation results are presented to illustrate the performance of the control law.

Adaptive output-feedback control for trajectory tracking of electrically driven non-holonomic mobile robots

In this study, the authors propose an adaptive output-feedback controller for trajectory tracking of electrically driven non-holonomic mobile robots in the presence of parametric uncertainties. A new adaptive observer using the transformation matrices is developed to estimate the unmeasured velocities of the mobile robot. By using the transformation matrices, the designed adaptive observer can deal with quadratic velocity terms caused by the Coriolis matrix in the mobile robot dynamics as well as uncertain parameters in quadratic velocity terms. Based on the designed adaptive observer, a simple tracking controller at the actuator level is induced from the dynamic surface design methodology. Using the Lyapunov stability theory, the authors prove that all errors in a closed-loop system are uniformly ultimately bounded and converge to an adjustable neighbourhood of the origin.

Dynamics and Trajectory Tracking of a Spherical Mobile Robot on an Inclined Plane

Dynamics and Trajectory Tracking of a Spherical Mobile Robot on an Inclined Plane

Применение лаконичных форм уравнений движения в динамике неголономных мобильных роботов

Применение лаконичных форм уравнений движения в динамике неголономных мобильных роботов

Analysis of a dual-arm mobile robot dynamics and balance compensation

The kinematic and dynamic behaviours of a robot manipulator on an elastic catenary cable were investigated. The dynamic equations of the robot and the cable were derived based on the Newton-Euler principle and Hamilton principle respectively. The recursive formulations describing the nonlinear and coupling dynamics relationship between the robot and the cable were presented. Based on the rigid-flexible coupling model proposed in this paper, a dynamic compensation technique with complementary control strategy was discussed which was implemented to adjust the posture of the robot and restrain the vibration that arise the flexible characteristics of the cable. The simulation and experiment results shown in this paper validate the effectiveness of the dynamic compensation.

Adaptive Tracking Control of an Uncertain Nonholonomic Robot

In this paper, a new controller is proposed by using backstepping method for the trajectory tracking problem of nonholonomic dynamic mobile robots with nonholonomic constraints under the condition that there is a distance between the mass center and the geometrical center and the distance is unknown. And an adaptive feedback controller is also proposed for the case that some kinematic parameters and dynamic parameters are uncertain. The asymptotical stability of the control system is proved with Lyapunov stability theory. The simulation results show the effectiveness of the proposed controller. The comparison with the previous methods is made to show the effectiveness of the method in this article.