Papers by Keyword: Impedance Control

Abstract: The results of the theoretical research and the computer simulation, aimed at increase in accuracy of robotic milling, are presented in the article. An analysis of the mathematical models of the system «technological robot – milling process» is conducted. The prospects of the usage of precision geared dual motor servo drives and trajectory-impedance control systems are underlined. A computer research of the tool movement accuracy during the robotic cylindrical up-milling process, depending on path velocity of the milling cutter and rated value of the cutting depth, has been carried out. Two types of manipulators have been considered: a manipulator with traditional geared servo drives with one motor and a manipulator with the suggested precision dual motor drives. In order to measure accuracy of movements during the computer simulation process a deviation of the tool, normal to the desired trajectory of its movement, has been defined. The results testify the facts that dual motor servo drives allow us to significantly increase dynamic stiffness of technological robots and they promote increasing accuracy and performance of robotic milling.

Abstract: The aim of this work is to investigate the performance of closed-loop impedance control in the case of a kinesthetic interface, more precisely to propose this control approach even for devices in which the natural dynamics of the system are relevant. This characteristic can be found in an industrial scenario where commercial components are generally used; hence the system can't be optimized as conversely occurs in a laboratory/ research environment where custom components are generally developed. It is shown that it is possible to guarantee a high dynamic accuracy using the closed-loop impedance control with force feedback and model feedforward. Therefore this approach is suggested as a valid alternative of the most diffused admittance control. The device implemented for the tests and the obtained results are described below.

Abstract: To meet the demand of the signal stable at high speed, the key is control precision for the characteristic impedance of FPC. This article is intended to study the strip-line structure for reducing cross-talk (noise) and their theoretical analysis and calculation. By varying effect factor and countermeasure in the production process of FPC, and the optimal process parameter have been obtained. By using the some testing technology, the impedance of strip-line in FPC have been tested.

Abstract: In this paper, the adaptive impedance control proposed by Seul is studied in detail aiming at the disadvantages of traditional impedance control algorithm. In simulation experiment, above two methods are used to control the planar robot. The performance of merits of two algorithms is analyzed detailedly. From the final result of simulation, the adaptive impedance control algorithm has the performance of robustness, that is: it can perform well as though the mathematical model of robot is not accurate and it can work well in the bad working circumstance.

Abstract: Because of lacking the imprecise mathematical model is a difficult problem in the area of dynamic control for robot manipulator. In this paper, a novel scheme which can realize the decoupling for robot by ANN inverse system in the inner loop and control the position and force in the outer loop is presented. The method is studied in the environment of Matlab and is realized by a manipulator in Lab. Analyzed from the experiment result, this algorithm is very feasible and it provides a basis for the further research.

Abstract: Aimed at improving the dynamic response of the lower limb for patients, an impedance control method based on sliding mode was presented to implement an active rehabilitation. Impedance control can achieve a target-reaching training without the help of a therapist and sliding mode control has a robustness to system uncertainty and vary limb strength. Simulations demonstrate the efficacy of the proposed method for lower limb rehabilitation.

Abstract: A novel strategy of online force distribution for multi-finger robot hand is developed based on impedance control. The real-time controller system including the finger dynamics and multi-fingers constraints is considered as a nonlinear system. Because when the robot hand grasps the object, the fingertip force is usually changed which could cause the grasp unstable. Our method gains the ability to deal with online grasping force distribution and can satisfy the real-time requirements at the same time. Experiment shows that our method provides the most feasible grasp configurations in real-time performance.

Abstract: The bilateral PD control method for teleoperation robot has some defects, such as poor tracking performance and force feedback performance. This paper, based on traditional bilateral PD control method, adds an impedance controller to the master and the slave, and deduces the stability condition according to the absolute stability criterion. The simulation shows that this method can assure the system stability and improve tracking performance and force feedback performance.

Abstract: In this paper, an iterative learning impedance control(ITLC) algorithm is proposed. We designed an adaptive impedance controller that can be modified using iterative learning method. Moreover, the convergence of the proposed robot system is proven using the Lyapunov function to guarantee the global convergence of tracking error. Finally, by simulating and comparing the proposed learning impedance control scheme with that of the traditional impedance control, it confirms the effectiveness of ILIC .

Abstract: This paper presents the design and control of a cleaning unit installed on a novel wall-cleaning robot (ROPE RIDE: RObotic Platform Enabling Rope access In Dangerous Environment). The proposed cleaning unit is able to autonomously avoid various obstacles on the wall of a building and also performs cleaning with sufficient contact force. The prototype of a cleaning unit is systematically designed and examined to verify its impedance-controlled cleaning performance.