in this study, a novel variable impedance control for a lower-limb rehabilitation robotic system using voltage control strategy is presented. the majority of existing control approaches are based on control torque strategy, which require the knowledge of robot dynamics as well as dynamic of patients. this requires the controller to overcome complex problems such as uncertainties and nonlinearit...

a mobile manipulator robot is known as a complex system due to some 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 ...

This paper presents a discrete-time robust control for electrically driven robot manipulators in the task space. A novel discrete-time model-free control law is proposed by employing an adaptive fuzzy estimator for the compensation of the uncertainty including model uncertainty, external disturbances and discretization error. Parameters of the fuzzy estimator are adapted to minimize the estimat...

In this paper, a task-space controller for electrically driven robot manipulators is developed using a robust control algorithm. The controller is designed using voltage control strategy. Based on the nominal model of the robotic arm, the desired signals for motor currents are calculated and then the voltage control law is proposed based on the current errors and motor nominal electrical model....

It is difficult to control the movement of the robot arm due to its nonlinear structure. PID controller is still in the world because of its simplicity in designing this controller as the main controller. The nonlinear control technique is very complicated, and this is not very interesting in the controller. While fuzzy control has a better performance, it incorporates a fuzzy control with ...

In this paper the design of a biped robot actuated with Shape Memory Alloy (SMA) springs with minimum degrees of freedom is presented. SMA springs are a class of smart materials that are known for their high power to mass and volume ratios. It was shown that utilizing spring type of SMAs have many advantages as large deformation, smooth motion, silent and clean movement compared to ordinary typ...

The electric arc furnace (EAF) is one of the popular methods of steel production from steel scraps. The plasma arc is used in EAF to generate heat for melting scarp or direct reduced iron (DRI). The liquid metal is drained from the EAF through the tap hole. Nowadays, it is critical to use Automated/robotic tools for opening the tap hole with oxygen lancing. Because many workers have been blinde...

Tracking control of the direct-drive robot manipulators in high-speed is a challenging problem. The Coriolis and centrifugal torques become dominant in the high-speed motion control. The dynamical model of the robotic system including the robot manipulator and actuators is highly nonlinear, heavily coupled, uncertain and computationally extensive in non-companion form. In order to overcome thes...

A simple easy to implement algorithm is proposed to address wall tracking task of an autonomous robot. The robot should navigate in unknown environments, find the nearest wall, and track it solely based on locally sensed data. The proposed method benefits from coupling fuzzy logic and Q-learning to meet requirements of autonomous navigations. Fuzzy if-then rules provide a reliable decision maki...

This paper presents a robust fractional order controller for flexible-joint electrically driven robots under imperfect transformation of control space. The proposed approach is free from manipulator dynamics, thus free from problems associated with torque control strategy in the design and implementation. As a result, the proposed controller is simple, fast response and superior to the torque c...