Aerial Contact Manipulation With Soft End-Effector Compliance and Inverse Kinematic Compensation

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Xinjun Sheng ◽  
Zhao Ma ◽  
Ningbin Zhang ◽  
Wei Dong
Keyword(s):  
Degrees Of Freedom ◽  
Position Control ◽  
Mechanical Design ◽  
Impact Resistance ◽  
High Strength ◽  
Inverse Kinematic ◽  
End Effector ◽  
Precise Position ◽  
Positioning Errors ◽  
Aerial Platform

Abstract This paper presents the development of a six degrees-of-freedom manipulator with soft end-effector and an inverse kinematic compensator for aerial contact manipulation. Realizing the fact that aerial manipulators can hardly achieve precise position control, a compliant manipulator with soft end-effector is first developed to moderate end-effector positioning errors. The manipulator is designed to be rigid-soft combined. The rigid robotic arm employs the lightweight but high-strength materials. The compliance requirement is achieved by the soft end-effector so that the mechanical design for the joints are largely simplified. These two features are beneficial to lighten the arm and to ensure the accuracy. In the meantime, the pneumatic soft end-effector can further moderate the probable insufficient accuracy by endowing the manipulator with compliance for impact resistance and robustness to positioning errors. With the well-designed manipulator, an inverse kinematic compensator is then proposed to eliminate lumped disturbances from the aerial platform. The compensator can ensure the stabilization of the end-effector by using state estimation from the aerial platform, which is robust and portable as the movement of the platform can be reliably obtained. Both the accuracy and compliance have been well demonstrated after being integrated into a hexarotor platform, and a representative scenario aerial task repairing the wind turbine blade-coating was completed successfully, showing the potential to accomplish complex aerial manipulation tasks.

Error Evaluation Method of Approximated Inverse Kinematics for Parallel-Wire Driven System – Basic Study for Three-Wire Planar System –

2016 ◽  
Vol 28 (6) ◽  
pp. 808-818 ◽  
Author(s):  
Hitoshi Kino ◽  
◽  
Nobuhiro Okubo ◽  
Toshihide Ikeda ◽  
Hiroaki Ochi ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Evaluation Method ◽  
Inverse Kinematic ◽  
Basic Study ◽  
Planar System ◽  
End Effector ◽  
Two Degrees Of Freedom ◽  
Parallel Wire ◽  
Positioning Errors ◽  
Driven System

[abstFig src='/00280006/04.jpg' width='300' text='Two-degrees-of-freedom planar system using three wires' ] Parallel-wire driven system, a kind of parallel-link mechanism, employs flexible and light wires in place of rigid links. By applying kinematics to parallel-wire driven systems, we seek to obtain the relationship between the end-effector’s position and wire length. Kinematics usually approximates the wire-contacting point of the winding reel (or guiding pulley) in the actuator unit to be a fixed point. Similar kinematic approximations, however, are likely to cause errors in controlling the end-effector position. In this study, therefore, we attempt to evaluate end-effector positioning errors due to inverse kinematic approximations. As the first step, we analyze end-effector positioning errors in two-degrees-of-freedom planar system and propose two methods to evaluate the positioning errors. Then, we conduct two case studies where we compare the errors due to inverse kinematic approximations and effects of wire’s elastic elements in order to confirm effectiveness of the proposed methods for evaluating end-effector positioning errors.

scholarly journals Analytical inverse kinematics for 5-DOF humanoid manipulator under arbitrarily specified unconstrained orientation of end-effector

Robotica ◽  
2014 ◽  
Vol 33 (4) ◽  
pp. 747-767 ◽  
Author(s):  
Masayuki Shimizu
Keyword(s):  
Analytical Method ◽  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Singularity Analysis ◽  
Inverse Kinematic ◽  
Inverse Kinematic Problem ◽  
Target Orientation ◽  
End Effector ◽  
Position And Orientation

SUMMARYThis paper proposes an analytical method of solving the inverse kinematic problem for a humanoid manipulator with five degrees-of-freedom (DOF) under the condition that the target orientation of the manipulator's end-effector is not constrained around an axis fixed with respect to the environment. Since the number of the joints is less than six, the inverse kinematic problem cannot be solved for arbitrarily specified position and orientation of the end-effector. To cope with the problem, a generalized unconstrained orientation is introduced in this paper. In addition, this paper conducts the singularity analysis to identify all singular conditions.

A New 4-DOF Fully Parallel Robot With Decoupled Rotation for Five-Axis Micromachining Applications

2019 ◽  
Vol 11 (3) ◽  
Author(s):  
Oleksandr Stepanenko ◽  
Ilian A. Bonev ◽  
Dimiter Zlatanov
Keyword(s):  
Degrees Of Freedom ◽  
Mechanical Design ◽  
Parallel Robot ◽  
Parallel Kinematic Machine ◽  
Constant Length ◽  
End Effector ◽  
Kinematic Models ◽  
Parallel Kinematic ◽  
Linear Actuators ◽  
Five Axis

We present a novel 4-DOF (degrees of freedom) parallel robot designed for five-axis micromachining applications. Two of its five telescoping legs operate simultaneously, thus acting as an extensible parallelogram linkage, and in conjunction with two other legs control the position of the tooltip. The fifth leg controls the tilt of the end-effector (a spindle), while a turntable fixed at the base of the robot controls the swivel of the workpiece. The robot is capable of tilting its end-effector up to 90 deg, for any tooltip position. In this paper, we study the mobility of the new parallel kinematic machine (PKM), describe its inverse and direct kinematic models, then study its singularities, and analyze its workspace. Finally, we propose a potential mechanical design for this PKM utilizing telescopic actuators as well as the procedure for optimizing it. In addition, we discuss the possibility of using constant-length legs and base-mounted linear actuators in order to increase the volume of the workspace.

Visual Control of Robotic Manipulator Based on Artificial Neural Network

1991 ◽  
Vol 3 (5) ◽  
pp. 394-400 ◽  
Author(s):  
Hideki Hashimoto ◽  
◽  
Takashi Kubota ◽  
Motoo Sato ◽  
Fumio Harashima ◽  
...  
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Visual Information ◽  
Degrees Of Freedom ◽  
Robotic Manipulator ◽  
Inverse Kinematic ◽  
End Effector ◽  
Control Scheme ◽  
Neural Network System ◽  
Artificial Neural

This paper describes a control scheme for a robotic manipulator system which uses visual information to position and orientate the end-effector. In the scheme the position and the orientation of the target workpiece with respect to the base frame of the robot are assumed to be unknown, but the desired relative position and orientation of the end-effector to the target workpiece are given in advance. The control system directly integrates visual data into the servoing process without subdividing the process into determination of the position, orientation of the workpiece and inverse kinematic calculation. An artificial neural network system is used for determining the change in joint angles required in order to achieve the desired position and orientaion. The proposed system can control the robot so that it approach the desired position and orientaion from arbitary initial ones. Simulation for the robotic manipulator with six degrees of freedom is done. The validity and the effectiveness of the proposed control scheme are varified by computer simulations.

Kinematic model to control the end-effector of a continuum robot for multi-axis processing

Robotica ◽  
2015 ◽  
Vol 35 (1) ◽  
pp. 224-240 ◽  
Author(s):  
Salvador Cobos-Guzman ◽  
David Palmer ◽  
Dragos Axinte
Keyword(s):  
Degrees Of Freedom ◽  
Kinematic Model ◽  
Euler Angle ◽  
Inverse Kinematic ◽  
End Effector ◽  
Six Degrees Of Freedom ◽  
Hazardous Environments ◽  
Continuum Robot ◽  
Novel Method ◽  
Six Dof

SUMMARYThis paper presents a novel kinematic approach for controlling the end-effector of a continuum robot for in-situ repair/inspection in restricted and hazardous environments. Forward and inverse kinematic (IK) models have been developed to control the last segment of the continuum robot for performing multi-axis processing tasks using the last six Degrees of Freedom (DoF). The forward kinematics (FK) is proposed using a combination of Euler angle representation and homogeneous matrices. Due to the redundancy of the system, different constraints are proposed to solve the IK for different cases; therefore, the IK model is solved for bending and direction angles between (−π/2 to +π/2) radians. In addition, a novel method to calculate the Jacobian matrix is proposed for this type of hyper-redundant kinematics. The error between the results calculated using the proposed Jacobian algorithm and using the partial derivative equations of the FK map (with respect to linear and angular velocity) is evaluated. The error between the two models is found to be insignificant, thus, the Jacobian is validated as a method of calculating the IK for six DoF.

Hybrid Force-Position Control Three Fingers End Effector

2013 ◽  
Vol 346 ◽  
pp. 75-82
Author(s):  
Vladimir Prada Jiménez ◽  
Oscar Fernando Avilés Sánchez ◽  
Mauricio M. Mauledoux
Keyword(s):  
Degrees Of Freedom ◽  
Position Control ◽  
Kinematics And Dynamics ◽  
End Effector ◽  
Matlab Simulink ◽  
Two Degrees Of Freedom ◽  
Hybrid Controller

This paper describes the implementation of a hybrid controller to an end effector of threefingers, each finger with two degrees of freedom (2 DOF). Since the mobility of each phalanx showsthe workspace by finger. Modeling is presented which includes the kinematics and dynamics offector and implementation of force-position hybrid controller. Simulations are presented to validatethe behavior of the finger and the controller in Matlab Simulink.

Optimal Design of the Control System for an Industrial Robot Using DOE Technique and Regression Model

2014 ◽  
Vol 658 ◽  
pp. 626-631
Author(s):  
Monica Enescu ◽  
Cătălin Alexandru
Keyword(s):  
Control System ◽  
Optimal Design ◽  
Degrees Of Freedom ◽  
Goodness Of Fit ◽  
Industrial Robot ◽  
Regression Function ◽  
Inverse Kinematic ◽  
Linear Regression Models ◽  
End Effector ◽  
Revolute Joints

This paper approaches the optimization of the control system for an industrial robot with 6 axes (degrees of freedom), using design of experiments (DOE) and multiple linear regression models. The design objective refers to the desired trajectory of the end-effector, the aim being to minimize the difference between the desired (imposed) and current (measured) angles in the revolute joints of the robot. The correlation between the imposed trajectory of the end-effector and the corresponding angular motions in the six revolute joints is obtained through the inverse kinematic analysis. The characteristic parameters of the controllers are used as design variables in the optimization. The optimal design is based on the DOE Screening investigation strategy with the Full Factorial design type. This design was chosen in order to evaluate the effect of the factors and of their interaction on trajectory, and the levels of these factors needed to produce an optimal trajectory. By comparing actual data with data after optimization, it shows that the regression function is correct (in terms of goodness of fit). The dynamic model of the robotic system was developed in mechatronic concept, by integrating the mechanical device (designed in ADAMS/View) and the control system (MATLAB/Simulink) at the virtual prototype level. The optimization study is performed by using ADAMS/Insight.

scholarly journals Research on Kinematics and Pouring Law of a Mobile Heavy Load Pouring Robot

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Long Li ◽  
Chengjun Wang ◽  
Hongtao Wu
Keyword(s):  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Position Control ◽  
Screw Theory ◽  
Great Influence ◽  
Inverse Kinematic ◽  
The Novel ◽  
Heavy Load ◽  
Motion Characteristics ◽  
The Relationship

In order to meet the requirement of continuous pouring in many varieties and small batches in casting production, a mobile heavy load pouring robot is developed based on a new 4-UPU parallel mechanism due to its strong carrying capacity. Firstly, the instantaneous motion characteristics of the novel 4-UPU parallel mechanism with four degrees of freedom (DOF) are analyzed using screw theory. By using the geometric method, both the forward and inverse kinematic solutions of the proposed robot system are given out. Secondly, based on a common pouring ladle, the volume change of pouring liquid in pouring process and the relationship between tilting angular velocity and flow rate are analyzed, and the results show that the shape of the ladle and the design of the pouring mouth have great influence on the tilting model. It is an important basis for the division of the sectional model. Finally, a numerical example is given to verify the effectiveness of the developed tilting model. The mapping relation between the tilting model and the parallel mechanism shows that the pouring flow can be adjusted by controlling the movement of parallel manipulator. The research of this paper provides an important theoretical basis for the position control of mobile heavy load pouring robot and the research of pouring speed control.

Performance Mapping and Motion Simulation of a 4UPS+PU Redundantly Actuated Parallel Manipulator

2010 ◽  
Author(s):  
Zhen Gao ◽  
Dan Zhang
Keyword(s):  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Position Control ◽  
Parallel Manipulators ◽  
Inverse Kinematic ◽  
Reachable Workspace ◽  
Redundantly Actuated ◽  
Inverse Kinematic Analysis ◽  
Motion Characteristics ◽  
Operational Capacity

In this paper, a new 4UPS+PU redundantly actuated parallel manipulator is proposed. This mechanism possesses three degrees of freedom (DOF), one translation and two rotations. Different from general parallel manipulators, a passive leg is connected to both centers of the base and the moving platform to constrain the unwanted motion. The mobility study and inverse kinematic analysis are conducted. The reachable workspace is generated with boundary-searching based discretization method. The local and global performance indices including stiffness and dexterity and their atlas are investigated in details. Comprehensive simulation of kinematics, dynamics and proportional-integral-derivative (PID) position control are implemented based on Adams to evaluate and testify the high operational capacity and well motion characteristics.

Modelling and Kinematic Analysis of a Built Up Linear Delta Robot

2012 ◽  
Vol 186 ◽  
pp. 234-238
Author(s):  
Erol Uyar ◽  
Lutfi Mutlu
Keyword(s):  
Simulation Model ◽  
Kinematic Analysis ◽  
Position Control ◽  
Mechanical Design ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Inverse Kinematic ◽  
Kinematic Parameters ◽  
Dc Motors ◽  
Three Dimensional Space

In this paper kinematic analysis of a 3-PUU translational parallel manipulator (TPM) is made by creating the forward and inverse Kinematic solutions. For a given position, control of the end effecter is then realized by using the calculated inverse kinematic parameters as reference values. For kinematic analysis relevant equations are derived from geometrical vector relations. For the forward and inverse kinematic solutions of the non-linear model a MATLAB based iterative algorithm is developed and the inverse kinematic solutions of limbs, are then used to control the end effecter position through screw rails which are driven by DC motors. After the general mechanical design of the manipulator all parts are drawn and modelled in SolidWorks, and a simulation of the motion in three dimensional space is made. To support the reliability of calculated parameters through inverse kinematic solutions, results are compared with the values of SolidWorks based simulation model of the manipulator. Furthermore a real position control with use of feed back encoders is applied and the evaluated results are compared with the results of a simulation model. Very similar and satisfactory results are obtained with both simulation and real application.

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