A mobile manipulator Robot is a complex system due to properties such as coupling between the manipulator and mobile chassis, holonomic and nonholonomic constraints, multivariable and nonlinear dynamics. The control of Robot faces the external disturbance, parametric uncertainty and unmodeled dynamics. Therefore, the use of an adaptive fuzzy system is suggested for its capability in overcoming uncertainties and approximating of nonlinear functions based on the universal approximation theorem. However, the tracking error does not converge asymptotically to zero due to the approximation error of fuzzy system. This paper presents a novel adaptive fuzzy control for a mobile manipulator Robot. The novelty of paper is compensating the approximation error of fuzzy system for asymptotic convergence in tracking the desired trajectory in the presence of uncertainties. For this purpose, the closed loop system in the error space converges to a linear system with poles having negative real parts. The control design consists of two parts; the kinematic control and dynamic control. Advantages of the proposed design are the simplicity and very good performance in tracking of the desired trajectory in the presence of uncertainties. The stability of control system and convergence to the desired trajectory are proven by the Lyapunov method. The simulation results show the superiority of the proposed control over a robust adaptive control.

When a rigid Robot is mounted on a flexible-link Robot or a flexible base, its reach capability is increased, but it looses its accuracy and speed due to the compliance of the base. A rigid manipulator attached to a flexible but unactuated base has been used to study a simple robust control strategy to reduce mechanical vibrations and achieve better tip positioning. The proposed control scheme uses the sensory feedback of the base oscillation to modulate the manipulator actuator input to induce the inertial damping forces. This algorithm is extended to a general case of nonlinear multiple-link manipulators using acceleration feedback and one sample delayed torque vector. The simulation study shows very promising results for a three-link manipulator mounted on a compliant base.

In the dynamic manipulation of objects, the aim is to throw an object by a Robot to the desired target even outside the reachable workspace. In this paper, the concept of the throw-able workspace or dynamic manipulation workspace is defined as a set of points which the Robot is able to throw the object at them. Thus, in order to obtain the maximum dynamic manipulation workspace which means the farthest points that object can be manipulated, it is necessary to solve the optimal throwing problem. To this end, the optimal throwing problem is defined as the optimal control problem solved using the indirect solution method based on the fundamental theorem of the calculus of variations. By applying the throwing equation as a moving boundary condition, the derived optimality conditions construct a two-point boundary value problem which its solution results in the optimal throwing. Finally, an algorithm is presented to calculate the maximum dynamic manipulation workspace. Then, simulation results are presented for a single link Robot in order to evaluate the defined concept as well as the effectiveness of the proposed method for problem-solving.

In this study, a SCARA PRR-type Robot manipulator is designed and implemented. Firstly, the SCARA Robot was designed according to the mechanical calculations. Then, forward and inverse kinematic equations of the Robot are derived by using D-H parameters and analytical methods. The software is developed according to obtain cartesian velocities from joint velocities and joint velocities from cartesian velocities. The trajectory planning is designed using the calculated kinematic equations and the simulation is performed in MATLAB VRML environment. A stepping motor is used for prismatic joint of the Robot, and servo motors are used for revolute joints. While most of the SCARA Robot studies focus on RRP-type servo control strategy, this work focuses PRR-type and both stepper and servo control structures. The objects in the desired points of the workspace are picked and placed to another desired point synchronously with the simulation. So the performance of the Robot is examined experimentally.

This paper presents the closed-form calibration procedure of a 5-Dof Mitsubishi Robot. In this method only the joint angle information is required. But due to the limitation of the Robot degrees of freedom it is not possible to attach the end-effector of the Robot directly to the ground; however, we can use a bar with two ball end joints for this purpose. By doing this, the Robot can move freely in space. The most limiting factor of the closed-loop calibration of Robot is that we cannot measure the non-moving joints, and we have to use other joint to estimate the motion of these joints. A novel approach to estimate the non-moving degrees of freedom are presented in the paper that can be extended to other Robots. Experimental results validate the proposed method and the deviation of the joint parameters compared with the nominal values of the Robot parameters delivered in the catalogue is very limited and are in an acceptable ranges.

In this paper, a Robust Integral of the Sign Error (RISE) feedback controller is designed for a Rigid-Link Electrically Driven (RLED) Robot manipulator actuated by direct current DC motor in presence of parametric uncertainties and additive disturbances. RISE feedback with implicitly learning capability is a continuous control method based on the Lyapunov stability analysis to compensate an additive bounded disturbance and linear in the parametric (LP) and non-linear in parametric (non-LP) uncertain dynamics through the use of a sufficiently large gain multiplied by an integral signum term. A proper selection of controller gains in predefined permitted areas for gains leads to reduce convergence time, control effort and improve the performance. The Bees Algorithm that is a search procedure inspired by the foraging behaviour of honey bees is used to tune the parameters of the controller to achieve the convergence. The performance of the proposed controller is compared with a PD and neural network based controllers. Simulation results of a two Rigid-Link Electrically-Driven Robot manipulator show the advantages of the proposed controller in terms of the transient and steady state performances in comparison with some conventional controllers.

In this paper, dynamic equations of motion of a 5 DoF Robot manipulator including ‎mechanical arms with revolute joints and their electrical actuators are considered. The ‎application of integrator backstepping technique for trajectory tracking in presence of ‎parameters of uncertainty and disturbance is studied. The advantage of this control ‎technique is that it imposes the desired properties of stability by fixing the candidate ‎Lyapunov functions initially, then by calculating the other functions in a recursive ‎way. Simulation results are presented in order to evaluate the tracking performance ‎and the global stability of the closed loop system. The validity and usefulness of the ‎proposed technique for Robot motion control when the system dynamics including ‎both mechanical arms and electrical actuators become more complex is obtained from ‎the results‏.‏

In this paper, we consider robust regulation of a class of nonlinear systems, via H¥, controller using slow-fast decomposition. First, using normal form equations, we eliminate the nonlinear part of the system matrix of equations of system and transform it to a linear diagonal form. Separating new equations to slow and fast subsystems, due to the two-time scale property of system, and with the assumption of norm-boundedness of the fast dynamics, we have treated them as disturbance and design H¥, controller for nominal system with a lower order than the original one that stabilizes the overall closed loop system. The proposed method is applied to a single link, flexible joint Robot manipulator.

Cell injection system in medicine is used to inject the materials into the cells. The injection system consists of injector and rotating plate. The controller sets height, position and orientation of the rotating plate. The proposal of this article is to replace SCARA Robot injection tool including ability in desired position tracking and is applied to time-varying force. In recent articles the control system is applied to the rotating plate of cells and this method can cause damage. The proposed method is fixed plate and to increase the success rate, the Robot is been controlled. The parameters of environmental models are estimated by nonlinear proposed models and by using the recursive method, the minimum of square errors will be optimal. The voltage strategy can control Robot actuators. This method is simpler and free from the manipulator dynamics. In all recent studies, the impedance control is based on the torque control method and the proposed method of this article is to apply the impedance control using voltage control. The robust adaptive impedance controller is designed in the presence of uncertainties. The simulation's results demonstrate desired performance of the proposed method.

Material handling Robots are replacing human workers in most of the manufacturing shop floors. Robot operating system is an open-source framework that enables visualization and implements various complex Robots and their functions. A 6-DoF Robotic manipulator with a gripper is designed to perform the pick and place operations. The aim is to integrate the designed Robot with the Robot operating system. The integrated system is then visualized and controlled using a gazebo and RViz to perform pick and place operations.