3113 6自由度マニピュレータの位置・姿勢・力・モーメントのハイブリッド制御 : 任意方向の実現およびRPY型実機での検証(マニピュレータ)

In this paper, a family of hybrid control algorithms is presented; where it is merged a free camera-calibration image-based control scheme and a direct force controller, both with the same priority level. The aim of this generalised hybrid controller is to regulate the robot-environment interaction into a two-dimensional task-space. The design of the proposed control structure takes into account most of the dynamic effects present in robot manipulators whose inputs are torque signals. As examples of this generalised structure of hybrid force/vision controllers, a linear proportional-derivative structure and a nonlinear proportional-derivative one (based on the hyperbolic tangent function) are presented. The corresponding stability analysis, using Lyapunov's direct method and invariance theory, is performed to proof the asymptotic stability of the equilibrium vector of the closed-loop system. Experimental tests of the control scheme are presented and a suitable performance is observed in all the cases. Unlike most of the previously presented hybrid schemes, the control structure proposed herein achieves soft contact forces without overshoots, fast convergence of force and position error signals, robustness of the controller in the face of some uncertainties (such as camera rotation), and safe operation of the robot actuators when saturating functions (non-linear case) are used in the mathematical structure. This is one of the first works to propose a generalized structure of hybrid force/vision control that includes a closed loop stability analysis for torque-driven robot manipulators.

This paper realizes the uncalibrated visual servoless control of the Six-DOF manipulator, where the intrinsic and extrinsic parameters of the camera and the robot manipulator model are not known, nor real-time computes the inverse of image Jacobian. And the neural network was used to optimize the trajectory of manipulator end in Cartesian space. Firstly, a biaxial parallel layoutt are proposed to establish the relationship between the moving component along the coordinate axis and the change of single image feature when the end of the robot moves in the Cartesian space. The neural network was used to fit the relationship established above, then the optimization model was established, and the parameter of PID controller were optimized by neural network. Finally, the simulation and comparison experiments are investigated, and the results indicate the controller posed in this paper is effective and stable.

This book is the second edition of a textbook published in 1996 by McGraw Hill and originates from a graduate level course given by the authors at the University of Naples. The topics include kinematics, statics and dynamics of robot manipulators together with trajectory planning and active control. There are only minor additions the first edition, which are mainly the use of quaternion to describe the orientation of the end effector and a short description of a closed chain architecture for a manipulator (parallelogram arm). The book is largely devoted to serial manipulators, with special developments about active control including adaptative control, robust controls and stability analysis. Another strength of this book is the great number of problems proposed at the end of each chapter, together with a list of references related to it. The fundamental features covered by the text are illustrated on simple examples of serial manipulators (two-link planar arm, parallelogram arm) including analytical results and numerical tests.The book has nine chapters followed by three appendices. The first appendix is devoted to linear algebra, the second recalls some fundamental aspects of rigid body mechanics and the third gives some basic principles of feedback control of linear systems.Chapter one is an introduction to the study of robot manipulators, giving an interesting classification of their architectures, the corresponding workspace and describes the tasks for which theyare used. After some standard examples of industrial manipulators, bibliographical reference texts are proposed, including textbooks on modelling and control of robots, general books on robotics, specialized texts, scientific robotic reviews and some international conferences on robotics.Chapters two, three and four are devoted to mechanical modelling of robot manipulators. The fundamental basics of kinematics are given in chapter two, including the representation of finite rotations by Euler angles or unit quaternions, homogeneous transformations, Denavit-Hartenberg parameters and workspace. The direct and inverse kinematical problems are solved in analytical form for some typical manipulator structures. The differential kinematics of robots are presented in chapter three, with an introduction to the geometric and analytic Jacobian matrices, kinematic singularities and redundancy. The inverse kinematic problem is presented, with special attention to the case of redundant robots where the solution is obtained by a linear optimization problem leading to the introduction of the pseudo-inverse Jacobian matrix and to the solution of several objectives such as avoidance of collision with an obstacle or moving away from singularities. Several inverse kinematics algorithms are given wih an interesting application to a three-link planar arm. Finally, a property of kineto-statics duality is deduced from the principle of virtual work applied to an equilibrium configuration of the robot. Chapter four is a standard presentation of the derivation of the dynamical model by Lagrange formulation and then by the Newton-Euler method. In the Lagrange formulation method, the linearity with respect to inertial parameters is shown and a detailed formulation of the dynamical model is obtained for a two-link Cartesian arm, a two-link planar arm and a parallelogram arm. The problem of dynamic parameter identification is also briefly presented from a numerical point of view. The recursive algorithm constructed from the Newton-Euler formulation is presented and illustrated by considering a two-link planar arm. Finally, the operational space dynamic model is introduced.In chapter five, paths and trajectory planning in joints and in operational spaces are presented; several classical methods of interpolation are described.Chapter six is an extensive study of active control of manipulators. Several methods are presented, involving classical independent joint control, non-linear centralized control, robust control and adaptative control. Both joint-space control and operational-space control are studied together with stability analysis by using Liapounoff functions. An interesting application to the two-link planar arm already used shows the comparison between various control schemes.Chapter seven deals with interaction control of serial manipulators with the working environment. Several strategies involving compliance control, impedance control, force control and hybrid control are presented.Chapter eight describes the actuators and the sensors used in robotics. Several types of servomotors (electric and hydraulic) are presented, together with the model giving their input/output relationship. Several kinds of sensors are also described including encoders, tachometers, force and vision sensors.The last chapter gives a short presentation of the functional architecture of a robot's control system, including characteristics of the programing environment and the hardware architecture.In conclusion, the book provides a good insight about simulation and control of robot manipulators, with a detailed study of the various control strategies and several interesting and pedagogical applications. This book is an excellent review of the standard knowledge needed not only for graduate students but also for researchers interested in robot manipulators.M Pascal

We investigate the control of a two-link robot manipulator through the application of sliding mode control (SMC), proportional-integral-derivative (PID) control, and their hybrid control strategy.Firstly, a mathematical model incorporating nonlinear coupling effects is derived based on the Lagrangian method.Then, SMC, PID, and hybrid controllers are compared based on disturbance rejection, stability, and time-domain responses.In addition, a genetic algorithm (GA) is employed for PID parameter optimization, improving system performance and efficiency.Overall, the PID-SMC controller achieves an effective balance between stability and response tracking accuracy.The results of this study provide a reference for control strategy development in robotic systems, aligning with smart manufacturing applications.

In this paper, the problem of combined vision/force servo control for robot manipulator is addressed. Three different robot vision control strategies: position-based, image-based, and hybrid control are combined with an impedance-based force controller and a comparison of these three combined vision/force control methods is investigated for the first time, in the context of generic robot kinematic-based sensory-task-space control structure. Furthermore, the issue of contact surface parameters estimation is also investigated. Simulation results have demonstrated that all the above vision/force control strategies are comparable in terms of both the dynamic response and accuracy of positioning and force control.

The control system of a high-DOF human-interaction robot requires the high-frequency simultaneous control of multiple joints, which needs the capability to handle computation-massive tasks with low latancies. Aiming at the force control of 2-DOF fluid-actuated manipulator, I'm going to introduce a distributed infrastructure design with good flexibility and scalability, while maintaining a high-quality real-time performance. In this thesis, a motor control library, arranged on a core-isolated real-time machine, is developed to provide control implementers with functional APIs and input/output mapping of low-level data structures from SOEM (Simple Open EtherCAT Master) interfacing the direct-drive motors and peripheral sensors via EtherCAT bus communication. While on a remote machine, the ROS (Robot Operating System) is deployed to deal with high-level non-realtime applications, including algorithm processing, data visualization and status analysis. At the same time, a user-friendly Python proxy with a couple of control APIs are offered as an auxiliary medium besides the ROS native interfaces. To synchronize the user-facing data on both sides, a robust ROS interface is developed using the Shared Memory technique which is an IPC (Inter-Process Conmmunication) mechanism supported by Linux POSIX standards. The teleoperation experiment demonstrates that the robot system can operate the closed-loop control consistently at 2 kHz, while limiting the loaded latency below 100 us. In addition, the collision detection test shows both dexterity and maneuverability under unknown environments.

In this paper, direct torque control (DTC) of hybrid stepping motor was investigated. Because of the structural characteristics, stepping motor is usually used for open-looped control. But, only the average torque of stepping motor is controlled by traditional control strategy, which causes intense ripple of torque and speed. Therefore, the torque must be controlled instantaneously to improve the performance of stepping motor. At first, open-looped control of stepping motor is analyzed. In order to get excellent performance, the curves of acceleration and deceleration of stepping motor must be calculated beforehand. Secondly, DTC of AC motor is introduced into the control of hybrid stepping motor. The effects of stator voltage space vectors on stator flux linkage and torque are also analyzed in details. Finally, a sensorless direct torque control system of hybrid stepping motor based on DSP-TMS320F240 is built up. The simulations and experiments validated the feasibility of the proposed system.

This paper presents the analysis and design of artificial neural network (ANN) and proportional and integral (PI) controller-based hybrid control (HC) of doubly fed induction generator (DFIG). The proposed HC gives the quick dynamic and good transient response during the sudden changes in wind speed. Further performance of proposed hybrid controller has been analyzed independently with ANN and PI control as its components. The HC with ANN gives better performance compared with conventional direct torque control (CDTC) and PI DTC in terms of flux ripples, torque ripples, and settling time. The proposed technique is implemented in real-time simulator (RTS)-based OPAL-RT and MATLALAB/SIMULINK environment at a rating of 5.5-kW system under step and randomly change in wind velocity.

In the last two decades, there have been great advances in using Unmanned Aerial Vehicles (UAVs) in several applications. This rapid growth is due to their ability to carry out several types of tasks with high flexibility aligned with reduced risks to human life and cost-effectiveness. The increasing demands for more complex assignments have improved UAVs' capabilities, propelling the rise of platforms with a high degree of autonomy for performing simultaneous tasks with less human intervention. One of the great challenges of maneuvering a UAV for a stabilized flight consists of a highly-coupled nonlinear system with fast dynamics. Thus, attitude control is an essential issue for stabilizing the vehicle or for keeping it in the desired orientation. The PID controller is often used due to its simple structure, good stability properties, and less dependence on the exact system model. However, its tuning process may become complicated in the face of the system nonlinearities. In this scenario, an adjustment error can cause it to lose its flight stability. Therefore, the main contribution of this work is the development of a Fuzzy-PID hybrid controller to control a quadrotor UAV's height stability. The work also considers a classic PID controller for comparison purposes with the proposed hybrid controller. The ROS/Gazebo platform was used to carry out the experiments with both control structures. From the results, it was possible to verify that both PID and Fuzzy-PID controllers could perform the attitude control of the UAV. However, the hybrid control strategy obtained some advantages, such as self-adjustment through system variations.

Obtaining the required performance, stability, and robustness in real-time control of induction motors usually requires the use of complex controllers, however through multiple experimentations, many challenges have arisen from such methods. The complex structure of control methods in real-time applications is usually computationally challenging and energy consuming, hence the need for a simple control strategy to overcome these challenges, in this paper, we focus on designing an advanced hybrid control strategy with a simple design applied to an induction motor. Mainly, the hybrid controller used in this study has the benefits of joining the best performance of both fuzzy logic controller and sliding mode controller, specifically designed to handle each phase separately, the transition phase and the steady phase. A fuzzy controller intervenes as a supervisor in our control structure, more specifically it manages the switch from one type of control to the other taking into account the intervention phase of each type of controller by commanding the rate of both controllers. Control performance analysis was carried out in a real experimental setup to validate the efficiency and robustness of the proposed hybrid controller and confirm its effectiveness in handling the compromise between overshoot and response time.

A novel hybrid control strategy for reducing torque ripple in permanent magnet brushless direct current motors has been developed by combining the deterministic nature of direct torque control and the adaptive nature of fuzzy logic control. Direct torque control using space vector pulse width modulation has been developed. This technique ensures the near-sinusoidal nature of the stator and rotor current. The impact of commutation ripple corresponding to the sinusoidal current is reduced compared to square wave current in conventional direct torque control. Further, the fuzzy logic controller provides adaptive modulation in space vector to mitigate the torque ripple. The response of the proposed method has been analyzed in the time domain as well as in the frequency domain. Experimental results establish a significant reduction in torque ripple and minimization of high-frequency components. A comparative study with conventional direct torque control methods has also been presented.

Toward combating the malicious rumor spreading on online social networks, we discuss a hybrid control strategy that combines a continuous truth spreading method and an impulsive rumor blocking method in this article. In this strategy, the truth is introduced as an anti-rumor to compete with the rumor while the rumor-infected users would be quarantined with a limited isolation period. The stability of the rumor-free equilibrium of the rumor-truth propagation system is analyzed and conditions to reach uniform asymptotic stability as well as global exponential stability are obtained. For the endemic case, the conditions under which rumor would persist uniformly are obtained. An optimal hybrid control problem is formulated to address the tradeoff between restraining rumor and minimizing the cost of control. The necessary conditions for optimal system and the structure of optimal hybrid control are obtained. Numerical simulations are carried out to illustrate the theoretical results and evaluate the potential roles of the hybrid control strategy.

The proportional-integral-derivative (PID) controller is still the most dominant form of feedback control in use because of its simplicity and efficiency to produce powerful solutions for most cases of industrial processes. However, the PID controller may be inadequate for nonlinear and non-minimum phase systems since the design of the controller is based on constant gain values. On the other hand, many advanced control methods have been proposed to overcome the limitations of the PID controllers. These control methods have highly dynamic structures to minimize the resultant error by optimizing the control signal, but stability is their common problem. This study integrates the classical proportional-derivative (PD) control with the self-tuning adaptive control in order to have a stable and dynamic control structure. The integral part (I) of PID is replaced by explicit self-tuning control to improve the performance of the proposed controller. Some experimental results on a hydraulic robot are presented for validation of the proposed concept of hybrid control.

of thesis entitled Robust Robot-Manipulator Control using Hybrid H-infinity/Adaptive Controller Structures submitted by TAM Hon Hung for the degree of Master of Philosophy at the University of Hong Kong in September 1998 Many advanced control schemes including control, adaptive control and variable-structure control have been developed to control the complicated dynamics of robot manipulators. Since these types of controller rely on the robot model, the basic structures of the schemes are very similar. It is found that these types of controllers can be integrated very easily while preserving all the merits of the individual ones. In this thesis, a general hybrid if / adaptive controller structure for robot manipulators with uncertainties and variations in some of the system dynamic parameters are developed. Using the HT optimization method, a linear controller is developed to reject the effect of model errors represented in the form of input disturbance. On the other hand, the adaptive controller adjusts the estimates of the model parameters continuously according to the tracking errors. Making use of Lyapunov stability theory/the proposed hybrid control structure is stable and the tracking error will converge to zero asymptotically. The applications of both output feedback and state-feedback iT control to an MRAC controlled robotic system are investigated. This hybrid controller type is extended to incorporate VSC and control while stability and convergence are still maintained. The controller schemes are tested by simulation and experiments. The performance of different hybrid controller structures is investigated and compared with that of the standalone controller.

A hybrid position/force controller is proposed for flexible link manipulators that make contact with the environment at more than one point. The dynamic equations of the motion with multiple contact constraints are derived. The dynamic equations are transformed into two subspaces (the constrained and constraint-free subspace) using singular value decomposition of the constraint equations. Each force and position controller is developed based on the orthogonality of these two subspaces. A hybrid controller is proposed from the new coordinates. Its stability is proved analytically under the quasi-static condition. An experimental study is carried out to justify the feasibility and application of the proposed ideas.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>