Admittance Force Tracking Control Schemes for Robot Manipulators under Uncertain Environment and Dynamics

Seul Jung,Do-Jin Jeong 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.11

Force control for robot manipulators is increasingly demanded for stable and desired interaction between robots and environments. In this paper, several modifications of an admittance force control scheme are presentedand derived from force tracking impedance functions to give a force tracking capability to position-controlled robot manipulators. Admittance force control known as the position-based force control has a structural advantage ofeasy implementation for the force control capability to the existing position-controlled robot systems by closing an outer force control loop. The admittance filter as an inverse of impedance function is implemented to filterforce errors to modify the reference position such that the eventual force tracking impedance control is realized indirectly. Admittance filters are formulated from impedance functions that guarantee the desired force/positiontracking performances with the help of the time-delayed controller. Desired contact force/position tracking control is achieved under uncertain environment and dynamics. Extensive simulation studies of force/position tracking controlperformances of the proposed control schemes for a robot manipulator are conducted to confirm the proposition.

Adaptive Position/Force Control for Robot Manipulators Using Force and Velocity Observer

Dao Minh Tuan,Phan Dinh Hieu 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.6

This paper presents an adaptive position/force control strategy and a velocity/force observer for three DOF robot manipulators APFC-VFO (Adaptive Position/Force Control-Velocity/Force Observer). The proposed control strategy based on the Slotine–Li adaptive control algorithm is designed to control the position and force of the end—efector robot interacting with the working environment. Moreover, the NGPI (New Generalized Proportional Integral) observer is established to estimate the velocity and force of robot manipulators. The advantages of the NGPI observer strongly reduce the oscillations of velocity and force under the efect of measurements noises. The observer convergence and control stability of the robot manipulator is proved in this paper. Finally, the simulation results are performed by Matlab Simulink software to validate the proposed control and observer.

원격 와이핑 작업을 위한 제어 기법

전지명,이승호,문일동,오재윤 전북대학교 공학연구원 ( 구 전북대학교 공업기술연구소 ) 2002 工學硏究 Vol.33 No.-

This study proposes a technique utilizing virtual information instead of real information in a teleoperated wiping operation. A teleoperation system composed of a master manipulator, a slave manipulator, and a real-time control system is used for this study. Both the master and slave manipulator have a kinematic structure effectively conveying and following the operator’s command respectively. The master manipulator uses DC servo motors to do a major role for counter balancing. A force sensor attached at the end of the slave manipulator’s end effector is used to measure a contact force. MATLAB/xPC Target is used for real-time control of the teleoperation system in Windows OS. This study proposes algorithms for generating the virtual force and the virtual velocity. They are generated as the master manipulator’s grip moves up and down, and back and forth. A force-force control technique proposing in this paper uses the virtual force as a reference input for the contact force control, and uses the virtual velocity as a reference input for control the slave manipulator’s horizontal movement. A PID controller is used as a local controller for the contact force control. In order to show the effectiveness of the proposing force-force control technique, experiments are performed on a plastic plate with two bumps.

Admittance Force Tracking Control for Position-Controlled Robot Manipulators Under Unknown Environment

Seul Jung 제어로봇시스템학회 2020 제어로봇시스템학회 국제학술대회 논문집 Vol.2020 No.10

In this paper, a position-based impedance force control scheme of a robot manipulator is formulated from the simple impedance function that guarantees the desired force tracking performance under totally unknown environment. The position-based force control has a structural advantage of easy implementation for providing the force control capability to the existing position-controlled robot systems by closing a force control outer loop. Desired contact force tracking control in association with the time-delayed control on the environment is guaranteed without knowing any information on the environment such as position and stiffness a priori. The contact force is indirectly regulated by the positional correction terms after the proposed admittance filter controls the impedance force. Simulation studies on force tracking control tasks of a robot manipulator are performed to verify the proposition.

Analysis of Bilinear Force Tracking Control for Robot Manipulators Under Unknown Environment

Seul Jung 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.12

This paper presents the analysis of bilinear force/position control (BFC) schemes for the guaranteed force tracking performance of a robot manipulator under unknown environment. Borrowing the concept of impedance force control and hybrid force control, BFC schemes are formulated by combining two force control algorithms. The proposed BFC scheme guarantees the desired force/position tracking performance for any environment with the help of a model-based control method by achieving independent axis control. Guaranteed force tracking control performances of three different bilinear functions are presented and analysed. Their performances are tested and compared without knowing any information on the environment such as position and stiffness a priori. Simulation studies of BFC tracking performances for a robot manipulator to follow the sinusoidal trajectory while regulating a desired force on the environment are performed to verify the practical force tracking control performance.

마사지 로봇의 다양한 힘 제어에 대한 실험 성능의 비교에 대한 연구

정도진(Do-Jin Jeong),정슬(Seul Jung) 제어로봇시스템학회 2021 제어·로봇·시스템학회 논문지 Vol.27 No.9

This paper presents a one-axis massage robot for humans. The massage robot is controlled by force control algorithms so that a force sensor is mounted to measure the contact force and a ball caster is attached at the end to minimize the friction force. The massage robot is installed to an x-y-z gantry type robot arm to move the end effector to a specific position on the object. Force is controlled in the z-axis direction only. Three distinct force control algorithms are tested. Two major force control algorithms, hybrid and impedance force control, are tested along with an explicit force control algorithm. Experimental studies are performed on the artificial skin of a human model for cardiopulmonary resuscitation (CPR) training. Force control performances by each algorithm are compared.

Simulation and Analysis of Dynamics of the Force-free Control for Industrial Robot Arms

Achala Pallegedara,Yoshitaka Matsuda,Naruto Egashira,Takenao Sugi,Satoru Goto 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10

Simulation and analysis of the dynamic force-free control of robot arm with revolute joints are presented in this paper. Initially, modeling of dynamic force-free control method is described. Then simulation is carried out for single arm and two arm links robots by adopting Matlab/Simulink environment. The model characteristics of the force-free control is utilized to demonstrate the autonomous safety action being taken by the robot arm in particular instances such as; when the robot insisting on an undesirable operation or a collision with an obstacle or an unusual dragging along the working objects. Finally, simulation results are taken by adopting the force-free control on robot arms with industrial mechatronics controllers. Moreover, analysis of the force-free control is carried out by using real robot parameters throughout the simulations. Since the force-free control is about to deal with external forces given to the robot arm, it can be used to illustrate the cooperative control between a human and a robot arm by means of passive motion through external force.

Force Control of a New 6-DOF Haptic Interface for a 6-DOF Serial Robot

Vu Minh Hung,Uhn Joo Na 제어로봇시스템학회 2010 제어로봇시스템학회 국제학술대회 논문집 Vol.2010 No.10

This paper presents force control systems of a new 6-DOF haptic interface for a 6-DOF serial robot. The haptic interface was designed to operate with three translations and three rotations. First open loop force control is implemented to demonstrate the feed forward static force control based on Jacobian matrix. The error of open loop control can be reduced by a PD controller. However this controller does not show good performance if the forces change directions rapidly. In addition the joint frictions and dynamics degrades the controller performance. Therefore a self-tuning fuzzy PD controller is designed to adjust the parameters of PD controller. Finally a master-slave control system for the haptic interface and serial robot is presented.

Control of Radial Force in Double Stator Type Bearingless Switched Reluctance Motor

Wei Peng,Zhenyao Xu,Dong-Hee Lee,Jin-Woo Ahn 대한전기학회 2013 Journal of Electrical Engineering & Technology Vol.8 No.4

Modeling and control of radial force in the double stator type bearingless switched reluctance motor (BLSRM) is researched. The rotational torque is controlled independently from the radial force control. And the radial force is constant which is independent from the rotor position. In order to realize steady suspension, analytical models of torque and radial force for the proposed structure are derived. Meanwhile, in order to realize steady suspension, control scheme for proposed BLSRM is proposed. In the control method, the radial force can be controlled in arbitrary direction and magnitude by selecting some combinations of radial force windings. The validities of structure and control method are verified by the experimental results.

Balance Control Strategy of Biped Walking Robot SUBO-1 Based on Force-Position Hybrid Control

Hyo-Joon Lee,Jung-Yup Kim 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.1

This paper deals with a balance control strategy based on a force-position hybrid control of biped walking robot, SUBO-1 for stable walking on irregular terrain environments. Walking robots basically require the position control of the leg to accurately land the swing foot on the correct position. Also, they need a force-based balance control to prevent them from falling over on irregular terrain. This study derives the location of the Zero Moment Point (ZMP) to control the Capture Point (CP) for keeping balance of the robot, and additionally obtains the total vertical force required for both feet to maintain the desired height of the Center of Mass (CoM). The vertical force, roll and pitch moments of each foot that optimally satisfies the derived ZMP and the total vertical force of the both feet, are calculated through the Quadratic Programming (QP). To realize the vertical force, roll and pitch moments of each foot, a feedforward control using Jacobian and a PI control using a force/torque sensor at the foot are used simultaneously, and the horizontal forces and yaw moment of each foot are used in Task-Space PD control for positioning of foot. Finally, the proposed method is verified through balance control experiments in double support and single support phases using the biped walking robot, SUBO-1 in the presence of external force and varying ground slope