scholarly journals On the Robot Compliant Motion Control

1989 ◽  
Vol 111 (3) ◽  
pp. 416-425 ◽  
Author(s):  
H. Kazerooni
Keyword(s):  
Control Method ◽  
Robot Manipulator ◽  
Direct Drive ◽  
End Effector ◽  
Compliant Motion ◽  
General Stability ◽  
Dc Motors ◽  
Nonlinear Approach ◽  
Fast Light ◽  
Miniature Robot

The work presented here is a nonlinear approach for the control and stability analysis of manipulative systems in compliant maneuvers. Stability of the environment and the manipulator taken as a whole has been investigated using unstructured models for the dynamic behavior of the robot manipulator and the environment, and a bound for stable manipulation has been derived. We show that for stability of the robot, there must be some initial compliancy either in the robot or in the environment. The general stability condition has been extended to the particular case where the environment is very rigid in comparison with the robot stiffness. A fast, light-weight, active end-effector (a miniature robot) which can be attached to the end-point of large commercial robots has been designed and built to verify the control method. The device is a planar, five-bar linkage which is driven by two direct drive, brush-less DC motors. The control method makes the end-effector to behave dynamically as a two-dimensional, Remote Center Compliance (RCC).

Robot Manipulator Vibration Resistance Control Based on Physical Model

2020 ◽  
Author(s):  
Ting-Sheng Chen ◽  
Jen-Yuan (James) Chang
Keyword(s):  
Control Method ◽  
Robot Manipulator ◽  
Path Following ◽  
Position Error ◽  
Machining Accuracy ◽  
Robot Arm ◽  
End Effector ◽  
Vibration Resistance ◽  
Mass Spring ◽  
Accuracy And Repeatability

Abstract The overwhelming manufacturing process with robotic arm has replaced human labors in handling and manufacturing work-pieces in factories. In these years, higher accuracy and repeatability are required for robotic manipulators to perform processes such as welding, deburring and grinding in factories. In these path-following processes, the manipulator’s end-effector often encounter position error caused by its vibrating structures. Therefore, the quality of machining accuracy and surface roughness becomes unstable and unsatisfied. For the purpose of avoiding the vibrations to occur in the robotic manipulator, this study aims to design a control method to reduce vibrations which is divided into two parts, namely (1) dynamic modeling the robot arm by applying modified mass-spring-damper model to each joints and links of the robot arm, and (2) realizing the control of the robot arm’s vibration resistance with predicated dynamics to compensate for the undesired dynamics, respectively. Through the proposed model, the response of each joints in different postures and different payloads applied at the end effector can be fully analyzed and the vibrations can be predicted and compensated. Results with the proposed vibration resistance control method indicate improvement of the model robot arm’s dynamic position error.

Development of an Active Worktable and Its Application to Force Control of Robot Manipulators

2000 ◽  
Vol 12 (3) ◽  
pp. 249-253
Author(s):  
Shin-ichi Nakajima ◽  
Keyword(s):  
Force Control ◽  
Degrees Of Freedom ◽  
Control Method ◽  
Robot Manipulator ◽  
Impedance Control ◽  
Robot Manipulators ◽  
Compliant Motion ◽  
Stiffness Control

An active worktable, which can be applied to force control tasks of commercial robot manipulators, has been designed and built. The active worktable has several degrees of freedom and accommodates its position/force in accordance with the motion of a robot manipulator. A stiffness control method and an impedance control method are implemented in the active worktable to achieve compliant motion. Several experiments were carried out to confirm basic effectiveness of the active worktable.

scholarly journals Adaptive speed control method for electromagnetic direct drive vehicle robot driver based on fuzzy logic

2019 ◽  
Vol 52 (9-10) ◽  
pp. 1344-1353 ◽  
Author(s):  
Gang Chen ◽  
Weigong Zhang ◽  
Xu Li ◽  
Bing Yu
Keyword(s):  
Fuzzy Logic ◽  
Control Method ◽  
Tracking Error ◽  
Speed Control ◽  
System Structure ◽  
Direct Drive ◽  
Test Standards ◽  
Speed Controller ◽  
Fuzzy Neural ◽  
Vehicle Test

To solve the shortcomings of existing control methods for an electromagnetic direct drive vehicle robot driver, including large speed tracking error and large mileage deviation, a new adaptive speed control method for the electromagnetic direct drive vehicle robot driver based on fuzzy logic is proposed in this paper. The electromagnetic direct drive vehicle robot driver adapts an electromagnetic linear motor as its drive mechanism. The control system structure is designed. The coordinated controller for multiple manipulators is presented. Moreover, an adaptive speed controller for the electromagnetic direct drive vehicle robot driver is proposed to achieve the accurate tracking of desired speed. Experiments are conducted using a Ford FOCUS car. Performances of the proposed method, proportional–integral–derivative, and fuzzy neural network are compared and analyzed. Experimental results demonstrate that the proposed control method can accurately track the target speed, and it can inhabit the change of speed caused by interference under different test conditions, and it has small mileage deviation, which can meet the requirements of national vehicle test standards.

The Design and Simulation for Two-Link Manipulators PD Robust Controller under Uncertain Upper Bound Disturbance

2013 ◽  
Vol 694-697 ◽  
pp. 1652-1655
Author(s):  
Ji Yan Wang
Keyword(s):  
Dynamic Characteristics ◽  
Upper Bound ◽  
Control Method ◽  
Robot Manipulator ◽  
Industrial Robot ◽  
Pd Controller ◽  
Robust Controller ◽  
Convergence And Stability ◽  
Comparison And Analysis ◽  
Driving Torque

PD control method is widely utilized for the dynamic characteristics controlling in industrial robot manipulator area. The disturbance is usually uncertain in reality; the traditional PD controller is limited in that case. In this paper, a PD robust controller is introduced to optimize the convergence and stability of PD controller and avoid the extreme initial driving torque for two-link manipulator system. Using the co-simulation on Matlab/ Simulink and ADAMS, the paper designs a PD robust controller under uncertain upper bound disturbance and completes track control and driving torque simulation trial. The superiority of the two-link manipulators PD robust controller is verified through result comparison and analysis.

Modelling and control of manipulators with flexible links working on land and underwater environments

Robotica ◽  
2010 ◽  
Vol 29 (3) ◽  
pp. 461-470 ◽  
Author(s):  
Levent Gümüşel ◽  
Nurhan Gürsel Özmen
Keyword(s):  
Fuzzy Control ◽  
Control Method ◽  
Robot Manipulator ◽  
Control Methods ◽  
Control Laws ◽  
Linear Ordinary Differential Equations ◽  
Intelligent Technique ◽  
Wide Range ◽  
Classical Control ◽  
And Control

SUMMARYIn this study, modelling and control of a two-link robot manipulator whose first link is rigid and the second one is flexible is considered for both land and underwater conditions. Governing equations of the systems are derived from Hamilton's Principle and differential eigenvalue problem. A computer program is developed to solve non-linear ordinary differential equations defining the system dynamics by using Runge–Kutta algorithm. The response of the system is evaluated and compared by applying classical control methods; proportional control and proportional + derivative (PD) control and an intelligent technique; integral augmented fuzzy control method. Modelling of drag torques applied to the manipulators moving horizontally under the water is presented. The study confirmed the success of the proposed integral augmented fuzzy control laws as well as classical control methods to drive flexible robots in a wide range of working envelope without overshoot compared to the classical controls.

Stability control for end effect of mobile manipulator in uneven terrain based on active disturbance rejection control

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chuang Cheng ◽  
Hui Zhang ◽  
Hui Peng ◽  
Zhiqian Zhou ◽  
Bailiang Chen ◽  
...  
Keyword(s):  
Disturbance Rejection ◽  
Control Method ◽  
External Disturbance ◽  
Stability Control ◽  
Mobile Manipulator ◽  
Active Disturbance Rejection Control ◽  
End Effector ◽  
Content Type ◽  
Active Disturbance Rejection ◽  
Disturbance Rejection Control

Purpose When the mobile manipulator is traveling on an unconstructed terrain, the external disturbance is generated. The load on the end of the mobile manipulator will be affected strictly by the disturbance. The purpose of this paper is to reject the disturbance and keep the end effector in a stable pose all the time, a control method is proposed for the onboard manipulator. Design/methodology/approach In this paper, the kinematics and dynamics models of the end pose stability control system for the tracked robot are built. Through the guidance of this model information, the control framework based on active disturbance rejection control (ADRC) is designed, which keeps the attitude of the end of the manipulator stable in the pitch, roll and yaw direction. Meanwhile, the control algorithm is operated with cloud computing because the research object, the rescue robot, aims to be lightweight and execute work with remote manipulation. Findings The challenging simulation experiments demonstrate that the methodology can achieve valid stability control performance in the challenging terrain road in terms of robustness and real-time. Originality/value This research facilitates the stable posture control of the end-effector of the mobile manipulator and maintains it in a suitable stable operating environment. The entire system can normally work even in dynamic disturbance scenarios and uncertain nonlinear modeling. Furthermore, an example is given to guide the parameter tuning of ADRC by using model information and estimate the unknown internal modeling uncertainty, which is difficult to be modeled or identified.

scholarly journals A Novel Kinematically Redundant Planar Parallel Robot Manipulator With Full Rotatability

2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Nicholas Baron ◽  
Andrew Philippides ◽  
Nicolas Rojas
Keyword(s):  
Potential Application ◽  
Robot Manipulator ◽  
Video Recording ◽  
Parallel Robot ◽  
Singularity Analysis ◽  
Geometric Method ◽  
Forward Kinematics ◽  
Online Video ◽  
End Effector ◽  
Moving Platform

This paper presents a novel kinematically redundant planar parallel robot manipulator, which has full rotatability. The proposed robot manipulator has an architecture that corresponds to a fundamental truss, meaning that it does not contain internal rigid structures when the actuators are locked. This also implies that its rigidity is not inherited from more general architectures or resulting from the combination of other fundamental structures. The introduced topology is a departure from the standard 3-RPR (or 3-RRR) mechanism on which most kinematically redundant planar parallel robot manipulators are based. The robot manipulator consists of a moving platform that is connected to the base via two RRR legs and connected to a ternary link, which is joined to the base by a passive revolute joint, via two other RRR legs. The resulting robot mechanism is kinematically redundant, being able to avoid the production of singularities and having unlimited rotational capability. The inverse and forward kinematics analyses of this novel robot manipulator are derived using distance-based techniques, and the singularity analysis is performed using a geometric method based on the properties of instantaneous centers of rotation. An example robot mechanism is analyzed numerically and physically tested; and a test trajectory where the end effector completes a full cycle rotation is reported. A link to an online video recording of such a capability, along with the avoidance of singularities and a potential application, is also provided.

scholarly journals A New Approach to the Solution of Robot Kinematics Based on Relative Transformation Matrices

2016 ◽  
Vol 5 (3) ◽  
pp. 213
Author(s):  
Mohammad Reza Elhami ◽  
Iman Dashti
Keyword(s):  
Robot Manipulator ◽  
Robot Kinematics ◽  
Coordinate Frame ◽  
End Effector ◽  
New Approach ◽  
Transformation Matrices ◽  
The World ◽  
Convenient Approach ◽  
Position And Orientation ◽  
Relative Transformation

In analyzing robot manipulator kinematics, we need to describe relative movement of adjacent linkages or joints in order to obtain the pose of end effector (both position and orientation) in reference coordinate frame. Denavit-Hartenberg established a method based on a 4×4 homogenous matrix so called “A” matrix. This method used by most of the authors for kinematics and dynamic analysis of the robot manipulators. Although it has many advantages, however, finding the elements of this matrix and link/joint’s parameters is sometimes complicated and confusing. By considering these difficulties, the authors proposed a new approach called ‘convenient approach’ that is developed based on “Relative Transformations Principle”. It provides a very simple and convenient way for the solution of robot kinematics compared to the conventional D-H representation. In order to clarify this point, the kinematics of the world known Stanford manipulator has been solved through D-H representation as well as convenient approach and the results are compared.

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