Omnidirectional Mobile Robot Research Articles

Improved FastSLAM2.0 using ANFIS and PSO

Wheeled mobile robots (WMRs) are of great importance. Therefore, it is necessary to make sure that they are not defected. But, in case of failures, the diagnosis task is very important to predict then solve the problem. The most useful techniques in diagnosis are observers which are based on the observability of the monitored system that is not usually ensured by WMR. Thus, to overcome this drawback, an intelligent cooperative diagnosis algorithm is proposed and tested for a group of mobile robots. The diagnosis algorithm is based on robust adaptive unknown input observer applied on unobservable robot. The local non-observability of each robot is solved by cooperative communication. The idea consists on considering all WMRs as a Large Scale System (LSS) even these robots may have not common task. Then, the LSS is decomposed into subsystems that everyone refers to each robot communicating with its neighbors. Next, a design of cooperative interconnected systems is studied to reassure the new condition of observability. Besides, Fast Adaptive Fault Estimation (FAFE) algorithm is proposed to improve the performances of the fault estimation. Finally, to illustrate the efficiency of the proposed algorithm, a model of three-wheel omnidirectional mobile robot is presented.

Fuzzy logic controllers design for omnidirectional mobile robot navigation

This paper presents a new design approach for an intelligent navigation algorithm for omnidirectional mobile robots. Unlike the previous works dealing with the navigation of omnidirectional robots that are focused on only the estimation of the final position, the main contribution of the present study is summed up in the fact that the robot has to reach the final desired position with a predefined final steering angle. This latter improvement is a part of researches carried out on Intelligent Transport Systems (ITS). Taking into consideration the drawbacks of proportional integral (PI) control when applied to omnidirectional robot navigation, we develop an approach to design a fuzzy logic PI controller (Fuzzy-PI).Preliminary simulation and experimental results using the Fuzzy-PI controller have shown limitations as the robot performed a larger path when the desired final angle increased. Thus, a deepen study have concluded that the Fuzzy-PI system cannot control at the same time the linear and angular velocities. To overcome these drawbacks, we propose to replace the previous intelligent navigation system by two independent controllers. The designed Fuzzy-PI controllers can adjust their parameters (KP, KI) to reduce the error caused by the dynamic changes and navigation challenges of omnidirectional robot. A navigation algorithm cannot be efficient without obstacle avoidance system. To achieve this goal, we have developed a third fuzzy controller to fulfill this task.To evaluate the real performances of fuzzy controllers for navigation and obstacles avoidance, simulation and experimental tests are performed for one, two and three obstacles. The obtained results confirm that the omnidirectional robot could navigate in an unstructured and unknown obstacles environment with better performances and efficiency.

Obstacle avoidance with translational and efficient rotational motion control considering movable gaps and footprint for autonomous mobile robot

This paper presents a sensor-based real-time obstacle avoidance method for an autonomous omnidirectional mobile robot based on simultaneous control of translational and efficient rotational motion considering movable gaps and the footprint. Autonomous mobile service robots that have been developed in recent years have arms that work and execute tasks. Depending on the task using moving parts, the shape of the robot (i.e., the footprint) changes. In this study, to improve the safety and possibility of reaching a goal even through a narrow gap with unknown obstacles, a sensor-based real-time obstacle avoidance method with simultaneous control of translational and efficient rotational motion (without unnecessary rotational motion) based on the evaluation of movable gaps and the footprint is proposed. To take account of the anisotropy footprint of the robot, multiple-circle robot model is proposed. In this paper, a novel control method based on fuzzy set theory is presented. To verify the effectiveness of the proposed method, several simulations and experiments are carried out.

Passivity-based control of an omnidirectional mobile robot.

This paper studies passivity-based trajectory tracking control of an omnidirectional mobile robot. The proposed control design is simple to be implemented in practice, because of an effective exploitation of the structure of robot dynamics. First, the passivity property of the prototype robot is analyzed. Then the control system is designed based on the energy shaping plus damping approach. We find that the prototype robot itself has enough damping forces. As a result, only energy shaping is needed in our proposed controller, while the damping injection is unnecessary for our robot. In other words, the disadvantages of differential feedback, such as amplifying the measurement noise, can be avoided. Globally asymptotic stability is guaranteed. Both simulations and experimental results show the effectiveness of the proposed control design.

Yaw Angle Measuring System of Omni-Directional Mobile Robot Based on EKF

For MEMS (Micro-Electro-Mechanical System) inertial sensor low precision, high noise and the characteristics of the gyroscope error accumulating, this paper designed a kind of yaw angle measuring system based on EKF (Extended Kalman Filter) by STM32 microcontroller and MEMS sensor. The EKF applys the attitude angle quaternion as the filter state variable, the angular rate as the filter time update. And application of the carrier location's gravitational field and geomagnetic data, complete filter measurement update, suppress divergent attitude error, obtain high accuracy and reliability of the attitude angle (pitch angle, roll angle, yaw angle) data. Experimental results show that the practical application of error control heading within ± 1º, with high practical value.

Analysis of factors related to vertical vibration of continuous alternate wheels for omnidirectional mobile robots

Omnidirectional mobile robots (OMRs) are capable of arbitrary motions in arbitrary directions without changing the direction of wheels since they perform 3-DOF (degree of freedoms) motions on a plane. Various omnidirectional wheels including the continuous alternate wheel (CAW) with passive rollers for OMRs have been researched. The CAW has been developed for the purpose of minimizing vibration. The CAW has alternating inner and outer rollers around the wheel which makes nearly continuous contact with the ground. The ideal CAW reduce vibration for certain; however, the real CAW fail to do so due to various errors. In this regard, more research is needed to bring vibration under acceptable tolerance. In this paper, vertical vibration characteristics of the real CAW with tolerance are researched. Simulation models of CAWs are implemented using flexible body dynamics of Recurdyn. To verify vibration characteristics of the model, simulation results are compared with experimental results from the improved CAW with five rollers set (CAW5). Vertical vibration is affected by various factors: geometry errors, the gap, the thickness of flexible body, the angular velocity, the alignment angle, the load and the elasticity of flexible body, etc. To efficiently analyze the effects of various factors, dynamic simulations are conducted using Taguchi method. As a result, it is found that the main factors which affect vibration are the angular velocity and the alignment angle followed by the geometry errors, the load, the elasticity of flexible body, the thickness of flexible body and the gap. This process can be applied to the analysis of the other omnidirectional wheels with passive rollers.

Trajectory Tracking Control for Omnidirectional Mobile Robots with Input Constraints

Trajectory Tracking Control for Omnidirectional Mobile Robots with Input Constraints

Front and Back Movement Analysis of a Triangle-Structured Three-Wheeled Omnidirectional Mobile Robot by Varying the Angles between Two Selected Wheels.

Omnidirectional robots can move in all directions without steering their wheels and it can rotate clockwise and counterclockwise with reference to their axis. In this paper, we focused only on front and back movement, to analyse the square- and triangle-structured omnidirectional robot movements. An omnidirectional mobile robot shows different performances with the different number of wheels and the omnidirectional mobile robot's chassis design. Research is going on in this field to improve the accurate movement capability of omnidirectional mobile robots. This paper presents a design of a unique device of Angle Variable Chassis (AVC) for linear movement analysis of a three-wheeled omnidirectional mobile robot (TWOMR), at various angles (θ) between the wheels. Basic mobility algorithm is developed by varying the angles between the two selected omnidirectional wheels in TWOMR. The experiment is carried out by varying the angles (θ = 30°, 45°, 60°, 90°, and 120°) between the two selected omniwheels and analysing the movement of TWOMR in forward direction and reverse direction on a smooth cement surface. Respectively, it is compared to itself for various angles (θ), to get its advantages and weaknesses. The conclusion of the paper provides effective movement of TWOMR at a particular angle (θ) and also the application of TWOMR in different situations.

Synthesis of the Optimal Fuzzy T-S Controller for the Mobile Robot Using the Chaos Theory

The automatic synthesis method of the optimal T-S controller has been proposed for nonlinear multiply dynamic object, omnidirectional mobile robot by using the chaos theory. A system of automatic adjustment of parameters of fuzzy controllers has been developed providing high-quality vector control parameters moving multiply nonlinear objects.

Synthesis of Robust Controller-regulators for Omnidirectional Mobile Robot with Irregular Movement

In this work an analytical synthesis method of TS fuzzy controller, which provides robustness according to stability degree for dynamic object having parametric uncertainty with irregular movement has been proposed. The effectiveness of the proposed method has been directly shown by the example of analytically synthesis of fuzzy regulator for omnidirectional (OD) mobile robot.

狭隘空間移動型への変形機構を持つ全方向移動ロボット

狭隘空間移動型への変形機構を持つ全方向移動ロボット

Error propagation and solvability in UAV localisation based on trilateration with a multi robot formation

This works presents how the propagation of errors from stations affects the trilateration, as seen from the error in the receiver covariance. Also, a method to calculate a solvability map in real-time is developed. This map is useful to select formations when using trilateration and to choose how a multi robot formation has to move in a given environment. The mathematical tools used are explained and proven in a real-time test and a simulation. The multi robot formation consists of omnidirectional wheeled mobile robots and an unmanned aerial vehicle in three dimensions.

The Application of Ultrasonic Positioning System for Indoor Navigation of Omni-directional Mobile Robot

The Application of Ultrasonic Positioning System for Indoor Navigation of Omni-directional Mobile Robot

外乱オブザーバによる全方向移動ロボットのスリップ評価

Recently, the robots which work in a hospital and factory have developed. The robot is expected to omni-directional motion to move in limited space. For a Mecanum wheels to be used in the wheels of the omni-directional mobile robot has a complex structure, depending on the situation of the road surface lose stability, movement is difficult. Also, due to the movement on the assumption of slip control becomes to be difficult with slippery road surface. In this study, the development of the omni-directional whole direction mobile robot equipped with a Mecanum wheels. And in order to improve the motion of the efficiency, it performs a slip correction and disturbance observer, to verify the running performance in the actual road surface.

Design and Development of an Omni-Directional Mobile Robot for Logistics of Printing Enterprise

Design and Development of an Omni-Directional Mobile Robot for Logistics of Printing Enterprise

Mechanical Design and Control System of an Omni-directional Mobile Robot for Material Conveying

This paper presents the mechanical design and control system of a material conveying mobile robot. The robot uses a four-wheel driven chassis and has omni-directional mobility. The mechanical system based on four Mecanum wheels is designed with a damping suspension mechanism. A Siemens S7-1217C PLC with extended modules is used as the lower-layer controller, while a laptop computer is used as the upper-layer controller. The control algorithm for the motion modes of the robot is developed, and the motion control performance is tested with a hand box based on its three-axis potentiometer inside. At last, the visual navigation algorithm based on Hough Transform is designed and an experimental confirmation is completed.

ロッカーボギー機構を用いた全方向移動プラットフォームの開発

In connection with the super-aging society, there exists a growing interest in omnidirectional powered-wheelchairs that have superior mobility in a narrow space. An omnidirectional mobile robot composed of active dual-wheel caster assemblies can use general wheels such as rubber tires, so that it is easily applied to a powered wheelchair. This study is aimed at developing an omnidirectional mobile platform using active dualwheel caster assemblies in consideration of the run in a public road. An omnidirectional mobile platform using a rocker-bogie suspension system is proposed to improve the running ability, and several active dual-wheel caster modules are produced so as to be used in such a platform. In this paper, we give an overview of the active dual-wheel caster assemblies and the proposed robot, and describe the process of actual production of such modules and the associated experimental results.

A Global Optimal Control Methodology and its Application to a Mobile Robot Model

Abstract: A global optimal control algorithm is developed and applied to an omni-directional mobile robot model. The aim is to search and find the most intense signal source among other signal sources in the operation region of the robot. In other words, the control problem is to find the global extremum point when there are local extremas. The locations of the signal sources are unknown and it is assumed that the signal magnitudes are maximum at the sources and their magnitudes are decreasing away from the sources. The distribution characteristics of the signals are unknown, i.e. the gradients of the signal distribution functions are unknown. The control algorithm also doesn’t need any position measurement of the robot itself. Only the signal magnitude should be measured via a sensor mounted on the robot. The simulation study shows the performance of the controller.

The Application of Ultrasonic Positioning System for Indoor Navigation of Omni-directional Mobile Robot

The Application of Ultrasonic Positioning System for Indoor Navigation of Omni-directional Mobile Robot

Path planning and obstacle avoidance for omni-directional mobile robot based on Kinect depth sensor

To enable robots to autonomously move and skirt obstacles in the field, the robots must be designed so that they can exercise self-localisation and path planning functions based on the results of sensor signal processing or image analysis. This research combines the Kinect depth sensor with the omni-directional camera to construct the vision system of FIRA RoboSot. We use the above two complementary devices to enable robots to position themselves and to detect their distance from obstacles. The data captured can be processed and used to construct the required digital map, assisting robots in completing path planning. For testing the performance of our approach, some experiment results show the ability of the proposed system to perform robust obstacle avoidance under indoor conditions. All these results have been proven for their excellence and feasibility.