Adaptive Kinematic Controller Research Articles

A general update rule for Lyapunov‐based adaptive control of mobile robots with wheel slip

SummaryIn this article, we introduce a novel family of Lyapunov‐based adaptive kinematic control laws developed to solve the trajectory tracking problem for a differential‐drive mobile robot under the influence of both longitudinal and lateral wheel slip. Each adaptive controller in this family is constructed by augmenting a nonadaptive nominal controller, originally designed for the slip‐free case, with an update rule capable of estimating the longitudinal slip. In the absence of lateral slip and under constant longitudinal slip, we establish the convergence of the trajectory tracking error to zero and, assuming a persistent excitation condition, we also demonstrate the convergence of the slip estimate error to zero. When lateral slip is present, we analyse a particular control law from our family of adaptive controllers. This law ensures the trajectory tracking error is uniformly ultimately bounded around the origin, demonstrating the robustness of our adaptive control scheme in dealing with time‐varying longitudinal and lateral slip. The validity of our approach is assessed through comprehensive numerical simulations.

Adaptive Skid-Steering Control Approach for Robots on Uncertain Inclined Planes with Redundant Load-Bearing Mobility.

Climbing manufacturing robots can create a revolutionary manufacturing paradigm for large and complex components, while the motion control of climbing manipulation-oriented robots (CMo-Rs) is still challenging considering anti-slippage problems. In this study, a CMo-R with full-scenery climbing capability and redundant load-bearing mobility is designed based on magnetic adsorption. A four-wheel kinematic model considering the slipping phenomenon is established. An adaptive kinematic control algorithm based on slip estimation using Lyapunov theory is designed for uncertain inclined planes. For comparison, the traditional PID-based algorithm without slip consideration is implemented as well. Numeric simulations are conducted to tackle the trajectory tracking problems for both circular and linear trajectories on the horizontal plane (HP), 50° inclined plane (50° IP), 60° inclined plane (60° IP), and vertical plane (VP). The results prove that our approach achieves better tracking accuracy. It demonstrated applicability in various climbing scenarios with uncertain inclined planes. The results of experiments also validate the feasibility, applicability, and stability of the proposed approach.

Adaptive Kinematic Control of Underwater Cable-Driven Parallel Robot

We previously proposed on the underwater cable-driven parallel robot (UCDPR), a system comprising multiple surface robots, and designed a modeling and trajectory tracking control method for it. However, the conventional trajectory tracking control of the UCDPR using the kinematic controller faced several issues. These included challenges in control gain tuning due to model uncertainty and a decline in trajectory tracking performance caused by changes in system characteristics due to environmental factors like current velocity. In response, this study focuses on the development of an adaptive kinematic controller. The aim is to mitigate the effects of uncertainties and other factors while ensuring effective trajectory tracking. This is achieved by incorporating an adaptive modification term into the conventional kinematic controller, which can be tuned adaptively in real-time. To validate the effectiveness of the adaptive kinematic controller, we conducted numerical simulations using a planar 2-DOF UCDPR.

Adaptive Image-Space Regulation for Robotic Systems

This brief investigates the image-space regulation problem for visually servoed robotic systems by considering the uncertainties in the camera model and the manipulator kinematics and dynamics. By exploiting the depth-related passivity of the overall system kinematics, we first propose an adaptive dynamic controller that avoids the image-space velocity measurement by introducing a filter. In addition, we further show how to utilize the passivity property to design an adaptive kinematic control scheme, which simplifies the controller structure of the visually servoed robotic systems with the assumption that the low-level control loop can guarantee the square-integrability and boundedness of the joint velocity tracking error. We prove that both the proposed adaptive controllers can ensure the asymptotic convergence of the image-space position error. The results from a numerical simulation and extensive experimental studies illustrate the performance of the proposed adaptive image-space regulation control schemes.

Design of Adaptive Kinematic Controller Using Radial Basis Function Neural Network for Trajectory Tracking Control of Differential-Drive Mobile Robot

Design of Adaptive Kinematic Controller Using Radial Basis Function Neural Network for Trajectory Tracking Control of Differential-Drive Mobile Robot

Robust contour tracking of nonholonomic mobile robots via adaptive velocity field motion planning scheme

SummaryThis paper aims at designing a contour tracking scheme based on an adaptive velocity field formulation, for the case of uncertain nonholonomic (differential drive) mobile robots, with its dynamic controller. First, to handle kinematic uncertainties that deviate the map of the velocity field into wheel velocities, a linear parameterization of the uncertain Jacobian operator is proposed to synthesize an adaptive kinematic controller that shapes correctly the velocity field. Then, a robust model‐free dynamic controller is proposed to compensate in finite time for uncertain dynamics and disturbances, enforcing the kinematic reference. Finally, a representative simulation study is discussed to show the reliability of the proposed scheme.

Demonstration-Guided Pose Planning and Tracking for Multi-Section Continuum Robots Considering Robot Dynamics

Recently, there has been an increased interest in the deployment of continuum robots in unstructured and challenging environments. However, the application of the state-of-the-art motion planning strategies, that have been developed for rigid robots, could be challenging in continuum robots. This, in fact, is due to the compliance that continuum robots possess besides their increased number of degrees of freedom. In this paper, a Demonstration Guided Pose Planning (DGPP) technique is proposed to learn and subsequently plan for spatial point-to-point motions for multi-section continuum robots. Motion demonstrations, including position and orientation, are collected from a human via a flexible input interface that is developed to command the continuum robot intuitively via teleoperation. A dynamic model based on Euler-Lagrange formalism is derived for a two-section continuum robot to be considered while planning for the robot motions. Meanwhile, a Proportional-Derivative (PD) computed torque controller with a Model Reference Adaptive Kinematic Control (MRAKC) scheme are developed to ensure the tracking performance against system uncertainties and disturbances. Also, the system stability analysis based on Lyapunov quadratic equation is proven. Simulation results prove that the proposed DGPP approach, along with the developed control scheme, have the ability to learn, generalize and reproduce spatial motions for a two-section continuum robot while avoiding both static and dynamic obstacles that could exist in the environments.

Adaptive Kinematic Control of a Robotic Venipuncture Device Based on Stereo Vision, Ultrasound, and Force Guidance.

Robotic systems have slowly entered the realm of modern medicine; however, outside the operating room, medical robotics has yet to be translated to more routine interventions such as blood sampling or intravenous fluid delivery. In this paper, we present a medical robot that safely and rapidly cannulates peripheral blood vessels-a procedure commonly known as venipuncture. The device uses near-infrared and ultrasound imaging to scan and select suitable injection sites, and a 9-DOF robot to insert the needle into the center of the vessel based on image and force guidance. We first present the system design and visual servoing scheme of the latest generation robot, and then evaluate the performance of the device through workspace simulations and free-space positioning tests. Finally, we perform a series of motion tracking experiments using stereo vision, ultrasound, and force sensing to guide the position and orientation of the needle tip. Positioning experiments indicate sub-millimeter accuracy and repeatability over the operating workspace of the system, while tracking studies demonstrate real-time needle servoing in response to moving targets. Lastly, robotic phantom cannulations demonstrate the use of multiple system states to confirm that the needle has reached the center of the vessel.

A Novel Trajectory Tracking Control Method for a Nonholonomic Mobile Robot with System Uncertainties and Disturbances

This paper focuses on the trajectory tracking problem of mobile robots with system uncertainties and disturbances. With the integration of a kinematic controller and a dynamic controller, a hybrid control method is presented. Firstly, an adaptive kinematic controller is proposed through the kinematic model and backstepping method. Secondly, a neural network dynamic controller is proposed, with the consideration of system uncertainties and disturbances. The stability of the proposed control scheme is verified via the Lyapunov method and Barbalat lemma. Finally, results of circular trajectory simulation have illustrated the effectiveness of the present control scheme.

Adaptive Trajectory Tracking Control for a Nonholonomic Mobile Robot

As one of the core issues of the mobile robot motion control, trajectory tracking has received extensive attention. At present, the solution of the problem only takes kinematic or dynamic model into account separately, so that the presented strategy is difficult to realize satisfactory tracking quality in practical application. Considering the unknown parameters of two models, this paper presents an adaptive controller for solving the trajectory tracking problem of a mobile robot. Firstly, an adaptive kinematic controller utilized to generate the command of velocity is designed based on Backstepping method. Then, in order to make the real velocity of mobile robot reach the desired velocity asymptotically, a dynamic adaptive controller is proposed adopting reference model and Lyapunov stability theory. Finally, through simulating typical trajectories including circular trajectory, fold line and parabola trajectory in normal and perturbed cases, the results illustrate that the control scheme can solve the tracking problem effectively. The proposed control law, which can tune the kinematic and dynamic model parameters online and overcome external disturbances, provides a novel method for improving trajectory tracking performance of the mobile robot.

Special Issue on Recent Advances in Robot Control

This special issue contains outstanding papers on robot control presented at international meetings in Japan in 2000. Featured topics include face robots, polishing robots, control for multifingered robotic hands, re configurable brachiating space robots, DD parallel robots, and robot control technologies such as a distributed robust motion controller, image-based visual servoing, fault adaptive kinematic control, and optimum control for a robot manipulator. We also will have a variety of topics such as shaft insert tasks in the robot task field, fingerprint image sensing in sensing technologies, compliance display, emergence of affective behavior, human/robot communication in interfaces, and workspace analysis of parallel manipulators in robot analysis. In preparing this special issue, we have asked authors to revise work presented at international meetings to include further analyses and experimental data to help make papers even more interesting and informative concerning the purposes of the study, analyses, experiments, and simulation. We thank Professor Kohei Ohnishi, Department of System Design Engineering, School of Science and Engineering, Keio University, for his complete, courteous assistance, and all of the authors who such unstinting time to update their papers for this special issue.

Fault Adaptive Kinematic Control Using Multiprocessor System and its Verification Using a Hyper-redundant Manipulator

Decentralized autonomous control architecture and self-organizing control architecture have several advantages in space robots, the most fascinating of which is an adaptation for partial faults. The Communications Research Laboratory have proposed an ""Orbital Maintenance System"" (OMS) that maintains a space system. We have developed a modular manipulator, which can be controlled by distributed processors in each module and can overcome partial failures. In this paper, we introduce a decentralized control algorithm for modular manipulators and discuss its performance in computer simulations and experiments. The algorithm proved useful for inspection in modular manipulators, and robust to partial faults.