Wheeled Mobile Robot Research Articles

Comparison of lunar rover wheel performance in soils with different cohesive properties

Wheeled mobile robots, rovers, are highly effective in lunar exploration. However, the lunar regolith can cause wheel slippage, resulting in an inability to travel for the rover. A single-wheel testbed is usually used to analyze a rover wheel’s driving performance. Our experiment can control the rotation and translation of the wheels separately, realizing experiments in any slippage condition. Moreover, this testbed can conduct experiments using regolith simulant with a cohesive property, in addition to Toyoura sand, which is non-cohesive sand collected from the earth.This paper presents the results of a driving test on two types of loose soil: Toyoura sand and regolith simulant (FJS-1). The wheel used in the experiment is the preliminary version of the actual flight model of a 10 kg class lunar exploration microrover. The results reveal that the traction performance on both sands improves as the slip ratio increases. The performance did not depend on velocity but on vertical load. It should be noted that the cohesive simulant shows a higher difference in traction performance than Toyoura sand. These findings, measured in detail from the low-slip to the high-slip range, contribute to the actual driving operation of the rover missions.

Cooperative Adaptive Consensus Tracking Control for Multiple Wheeled Mobile Robot Systems With Model Uncertainties and External Disturbances

Cooperative Adaptive Consensus Tracking Control for Multiple Wheeled Mobile Robot Systems With Model Uncertainties and External Disturbances

FRT*: fast reactive tree for mobile robot replanning in unknown dynamic environments

Purpose This study aims to introduce the fast reactive tree (FRT*) algorithm for enhancing replanning speed and reducing the overall cost of navigation in unknown dynamic environments. Design/methodology/approach FRT* comprises four key components: inverted tree build, convex hull construction, dead nodes inform activation and lazy-rewiring replanning. First, an initial path is found from the inverted tree where the valid structure is preserved to minimise re-exploration areas during the replanning phase. As the robot encounters environment changes, convex hulls are extracted to sparsely describe impacted areas. Next, the growth direction of the modified tree is biased by the inform activation of dead nodes to avoid unnecessary exploration. In the replanning phase, the tree structure is optimized using the proposed lazy-rewiring replanning to find a high-quality path with low computation burden. Findings A series of comprehensive simulation experiments demonstrate that the proposed FRT* algorithm can efficiently replan short-cost feasible paths in unknown dynamic environments. The differential wheeled mobile robot with varying reference linear velocities is used to validate the effectiveness and adaptability of the proposed strategy in real word scenarios. Furthermore, ablation studies are conducted to analyze the significance of the key components of FRT*. Originality/value The proposed FRT* algorithm introduces a novel approach to addressing the challenges of navigation in unknown dynamic environments. This capability allows mobile robots to safely and efficiently navigate through unknown and dynamic environments, making the method highly applicable to real-world scenarios.

Cloud/VPN-Based Remote Control of a Modular Production System Assisted by a Mobile Cyber-Physical Robotic System-Digital Twin Approach.

This paper deals with a "digital twin" (DT) approach for processing, reprocessing, and scrapping (P/R/S) technology running on a modular production system (MPS) assisted by a mobile cyber-physical robotic system (MCPRS). The main hardware architecture consists of four line-shaped workstations (WSs), a wheeled mobile robot (WMR) equipped with a robotic manipulator (RM) and a mobile visual servoing system (MVSS) mounted on the end effector. The system architecture integrates a hierarchical control system where each of the four WSs, in the MPS, is controlled by a Programable Logic Controller (PLC), all connected via Profibus DP to a central PLC. In addition to the connection via Profibus of the four PLCs, related to the WSs, to the main PLC, there are also the connections of other devices to the local networks, LAN Profinet and LAN Ethernet. There are the connections to the Internet, Cloud and Virtual Private Network (VPN) via WAN Ethernet by open platform communication unified architecture (OPC-UA). The overall system follows a DT approach that enables task planning through augmented reality (AR) and uses virtual reality (VR) for visualization through Synchronized Hybrid Petri Net (SHPN) simulation. Timed Petri Nets (TPNs) are used to control the processes within the MPS's workstations. Continuous Petri Nets (CPNs) handle the movement of the MCPRS. Task planning in AR enables users to interact with the system in real time using AR technology to visualize and plan tasks. SHPN in VR is a combination of TPNs and CPNs used in the virtual representation of the system to synchronize tasks between the MPS and MCPRS. The workpiece (WP) visits stations successively as it is moved along the line for processing. If the processed WP does not pass the quality test, it is taken from the last WS and is transported, by MCPRS, to the first WS where it will be considered for reprocessing or scrapping.

Stabilization control of wheeled mobile robot based on neural sliding mode under wheel slip conditions

Stabilization control of wheeled mobile robot based on neural sliding mode under wheel slip conditions

Trajectory-Tracking Control of an Autonomous Wheeled Mobile Robot Using Wheel Odometry and AMCL Techniques

Trajectory-Tracking Control of an Autonomous Wheeled Mobile Robot Using Wheel Odometry and AMCL Techniques

Two-layer path planning framework for WMRs in dynamic environments: Optimized ant colony algorithm and dynamic window approach

This paper proposes a two-layer path planning method for wheeled mobile robots (WMRs), where an improved ant colony optimization (ACO) and optimized dynamic window approach (DWA) algorithms are used, at the global and local layer, respectively. This method allows WMRs to plan a high-quality path under complex dynamic scenarios, while costing less traveling time and energy consumption. At the level of global path planning, a modified ACO algorithm is presented which incorporates a path duplicate counter, a new heuristic function and path smoothing operation to enhance the feasibility and robustness of global path planning. At the level of local path planning, based on DWA, an optimization method composed by energy evaluation and dynamic obstacle avoidance evaluation sub-function is proposed to save the energy cost, while enhancing the ability of WMRs to avoid moving obstacles. This study aims to enhance the efficiency and effectiveness of path planning for WMRs using a combination of ACO and DWA algorithms, such that the proposed algorithm can be applied to multi-obstacle environment to execute dynamic objects avoidance. Finally, a multi-blockage environment involved with dynamic obstacles are simulated to verify the proposed path planning method.

Design and Development of a Four-Wheeled Mobile Robot (WMR) for Any Terrain

This paper presents the design, development, and analysis of an all-terrain Wheeled Mobile Robot (WMR). A Wheeled Mobile Robot (WMR) is an autonomous robot that uses wheels for locomotion, allowing it to move efficiently on flat surfaces. These robots are commonly used in various applications, from industrial automation to service robots and research platforms. The robot aims to achieve high mobility on diverse terrains, remote teleoperation, and an effective payload handling capability. The research includes the design and implementation of the mechanical structure, electronic components, control systems, and robot performance analysis. Special focus is given to the kinematic behavior, vibration analysis, and simulation of various components. The robot can carry loads up to 5 kg and navigate complex terrains, including stair climbing. The methodology followed includes structure design, integration of electronic components, assembly, and subsequent trials and simulations. The results demonstrate the robot's potential for practical applications in diverse fields such as exploration, rescue operations, and industrial automation. In summary, wheeled mobile robots are versatile, efficient, and widely used in various industries. Their design carefully balances mechanical, electronic, and software components to achieve reliable and autonomous operation. As technology advances, WMRs become more capable and adaptable, expanding their range of applications.

Adaptive Dynamic Programming-Based Fixed-Time Optimal Control for Wheeled Mobile Robot

Adaptive Dynamic Programming-Based Fixed-Time Optimal Control for Wheeled Mobile Robot

Differential-Driven Wheeled Mobile Robot Mechanism with High Step-Climbing Ability

Differential-Driven Wheeled Mobile Robot Mechanism with High Step-Climbing Ability

A novel motion control approach for tethered wheeled mobile robot on extreme terrain

Some of the most valuable science targets for future exploration mission located at the extreme terrains of the planetary surfaces are currently inaccessible to the conventional rovers. The tethered mobile robot with one end fixed to the mother robot or an anchor point has the ability to rappel down steep slopes and traverse rocky terrain, and is a reasonable solution to the above missions. Since the model of the tethered mobile robot can be formulated as a cascade of kinematics and dynamics, a novel backstepping motion control approach is proposed in this paper, in which the kinematic and dynamic controllers are designed independently in a recursive way. In the proposed approach, the optimal distribution of the tether tension and the torque to drive the left and right wheels of the tethered robot is obtained based on the minimization of the system power consumption when the robot traveling on the extreme terrains. In addition, a nonlinear disturbance observer is integrated into the dynamic controller to estimate the disturbance from the rugged terrains. Simulations are performed to verify the effectiveness of the proposed algorithm.

Nonlinear Adaptive Optimal Control Design and Implementation for Trajectory Tracking of Four-Wheeled Mecanum Mobile Robots

This study proposes a nonlinear adaptive optimal control method, the adaptive H2 control method, applied to the trajectory tracking problem of the wheeled mobile robot (WMR) with four-wheel mecanum wheels. From the perspective of solving mathematical problems, finding an analytical adaptive control solution that satisfies the adaptive H2 performance criterion for the trajectory tracking problem of the WMR with four-wheel mecanum wheels is an extremely challenging task due to the high complexity of the dynamic system. To analytically derive the control law and adaptive control law for this trajectory tracking problem, a proportional-derivative (PD) type transformation is employed to formalize the trajectory tracking error dynamics between the WMR and the desired trajectory (DT). Based on an in-depth analysis of the trajectory tracking error dynamics, a closed-form adaptive control law is analytically derived from the highly complex nonlinear dynamic system equations. This control law provides a solution to the trajectory tracking problem of the WMR while satisfying the adaptive H2 performance criterion. The proposed adaptive nonlinear control method offers a simple control structure and advantages such as improved energy efficiency. Finally, simulations and experimental implementations were conducted to verify the performance of the proposed adaptive H2 control method and the H2 control method in tracking the DT. The results demonstrate that, compared to the H2 control method, the adaptive H2 control method exhibits superior trajectory tracking performance, particularly in the presence of significant model uncertainties.

Overview of suspension systems for mobile wheeled robots

A common type of transport system used in robotics is a wheeled platform with at least one drive axle and some form of suspension for each wheel. Autonomous navigation at high speed over rough terrain is a challenging and relevant task for wheeled robots. To achieve mobility on terrain, a wheeled robot must adapt and respond quickly. The suspension systems of mobile wheeled robots play a key role in ensuring their stability, maneuverability, and overall efficiency. This article presents a comprehensive overview of the different types of suspensions used in modern mobile wheeled robots. The main designs of passive and active, rigid and elastic suspensions are considered, as well as their features, advantages and disadvantages. As a result of the analysis, it was found that the optimal choice of suspension system depends on the specific operating conditions of the robot and the tasks set. For example, for robots operating in difficult terrain, suspensions with high damping are more suitable, while for robots performing precise maneuvers on a flat surface, suspension stiffness is more important. The article may be useful for engineers, researchers, and developers of robotic systems who seek to improve the designs of mobile wheeled robots and increase their efficiency and reliability. The conclusions and recommendations presented in the article can contribute to the development of new approaches to suspension design and optimization of existing solutions in the field of mobile robotics.

Modeling, Control and Guidance of an Autonomous Wheeled Mobile Robot AWMR: A Comparative Study Between Three Yaw Moment Control Techniques for Autopilot Design with Experimental Results

Modeling, Control and Guidance of an Autonomous Wheeled Mobile Robot AWMR: A Comparative Study Between Three Yaw Moment Control Techniques for Autopilot Design with Experimental Results

Path planning control in known environments using turning points

The path planning problem for a wheeled mobile robot (WMR) involves determining a collision-free path from a starting point to a target destination while optimizing a specific fitness function, such as minimizing distance, cost, or both, depending on the scenario. This research introduces a novel method for generating smooth paths for mobile robots in user-defined two-dimensional environments with stationary obstacles. The proposed method addresses the issue of local minima by utilizing free segments and path-planning turning points. The approach evaluates both path length and path safety as key objectives. Simulation results demonstrate that the proposed method effectively identifies optimal paths and validates the reliability of the control strategy for mobile robot navigation.

Formation control for multiple nonholonomic wheeled mobile robots based on integrated sliding mode controller and force function

In this paper, we present a novel method to achieve collision-free formation control for multiple nonholonomic wheeled mobile robots. By utilizing the leader–follower strategy, an integrated controller that combines a sliding mode controller for formation control and a force function for obstacle avoidance is proposed. To address the common chattering issue associated with sliding mode control, a novel depletion model is developed, which constrains the controller input to vary smoothly within a small range and effectively eliminates chattering. Additionally, a dynamic-gain structure is introduced to reconcile the conflicting demands of formation control and obstacle avoidance, providing enhanced coordination between the two tasks. Simulation and experiments’ results are provided to illustrate the effectiveness of the proposed method.

A robust distributed model predictive control strategy for Leader–Follower formation control of multiple perturbed wheeled mobile robotics

This article studies the formation and trajectory tracking control of multiple mobile robots with kinematic sub-systems. We proposed an effective design of robust distributed model predictive control (MPC) strategy for Leader–Follower formation control scheme in a group of multiple perturbed Wheeled Mobile Robotics (WMRs) with the consideration of tracking performance in not only the position but also the orientation, as well as the distance between the center and head in each WMR. Furthermore, the relation between formation control objective and non-holonomic property in each agent is also discussed. For the purpose of achieving the desired formation, according to trajectory of leader WMR, the barycentric of the formation requirement is known as corresponding virtual followers, and a distributed tube-MPC scheme is applied to each follower WMR for tracking a reference trajectory with not only the position but also its orientation. In addition, the stability and the performance tracking of multiple perturbed WMRs are investigated by employing Lyapunov stability theory with the indirect comparison method to be implemented by pointing out precisely the proposed terminal controller and the equivalent terminal region. Comprehensive simulation results in several scenarios demonstrate the validity of the proposed control scheme.

Robust Adaptive Extremum Seeking Control Without Persistence of Excitation: Theory to Experiment

ABSTRACTIn this article, we develop a novel adaptive extremum‐seeking control (AdESC) algorithm with robustness guarantees and without persistence of excitation (PE). Specifically, this builds on a proportional‐integral (PI)‐like parameter estimator. A zeroth‐order optimization framework is used, where the optimizer/agent can only query the numerical value of the cost function at the current coordinate given an unmodeled bounded disturbance. Since parameter estimation plays a decisive role in the stability and convergence properties of AdESC algorithm, it is also well established in the existing literature that to ensure parameter convergence a stringent PE condition is required. Here, we eliminate the need for a stringent PE condition by utilizing a novel set of weighted integral filter dynamics, while ensuring sufficient richness using a milder condition, called initial excitation (IE). Moreover, to validate the robustness guarantees towards unmodeled bounded disturbance, a detailed Lyapunov function based analysis is performed to establish the closed‐loop stability and convergence in the form of uniform ultimate boundedness (UUB). Furthermore, an experimental study using a unicycle wheeled mobile robot (WMR) is carried out as a proof‐of‐concept considering disturbance and disturbance‐free scenarios.

Fixed-time adaptive sliding mode-based trajectory tracking control for Wheeled Mobile Robot: Theoretical development and real-time implementation

Wheeled mobile robots (WMR) are common autonomous systems requiring efficient control methods. This work investigates fixed-time adaptive sliding mode control (FxT-ASMC) for the trajectory tracking task of a WMR subject to disturbances/uncertainties. The developed control strategy seeks to avoid the chattering problem, cope with disturbances when the upper limit is undefined, and enhance the convergence of the system states. Indeed, a new adaptive technique has been developed to effectively handle disturbances, even in the absence of prior knowledge regarding their upper bound. This technique consists in estimating the switching gain for each channel separately. On the other hand, an appropriate design of the reaching law ensures the fixed-time convergence of the sliding variables to zero. Additionally, sliding variables are designed in a way that guarantees the tracking errors will stabilize within a set amount of time. This kind of convergence was demonstrated using Lyapunov stability theory. In order to realize the trajectory tracking control structure, the FxT-ASMC system is incorporated with a classical kinematic controller. The efficiency of the suggested control methodology is proven via simulations and practical implementation.

Research on trajectory tracking of wheeled mobile robots using fuzzy PID based on TD3

Abstract This study addresses the issues and limitations of trajectory tracking for Non-holonomic wheeled mobile robot (NWMR) under traditional PID control, including low accuracy, high response delay, poor robustness, and stability concerns. We propose a strategy that combines the Twin Delayed Deep Deterministic Policy Gradient (TD3) algorithm with fuzzy PID control to optimize PID parameter tuning for more precise robot trajectory tracking. Fuzzy logic is introduced to adjust the PID controller parameters, making them more adaptive and robust. The bidirectional long short-term memory (BiLSTM) network enhances the time series processing capability of the Actor-Critic network, improving the system’s state representation and prediction abilities. A curiosity-driven exploration method is employed to increase policy diversity and avoid premature convergence. Simulation experiments using the ROS Noetic and Gazebo platforms demonstrate that this method significantly outperforms traditional PID and TD3 algorithms in terms of trajectory alignment, training time, accuracy, and stability.