scholarly journals A Combined Solution of the Inverse Kinematic Task in the Vicinity of the Singularities

2004 ◽  
Vol 8 (5) ◽  
pp. 514-522
Author(s):  
Imre J. Rudas ◽  
◽  
József K. Tar ◽  
János F. Bitó ◽  
Ágnes Szeghegyi ◽  
...  
Keyword(s):  
Inverse Kinematic ◽  
Robot Arm ◽  
Computational Power ◽  
Orientation Data ◽  
Differential Approach ◽  
Apply Genetic ◽  
Singular Domains ◽  
Combined Solution ◽  
Position And Orientation ◽  
Complex Algorithm

In the case of the traditional differential approach of solving the inverse kinematic task, depending on the desired trajectory that may approach, reach, and cross the boundaries of non-singular domains or domains of different degree of singularity, certain joint velocities may take huge values. Within the singularity it may happen that the desired task cannot exactly be solved, and that this imprecise solution has one or more degree of freedom in its ambiguity. The motion planner provided with end-point position and orientation data with respect to the workshop’s Cartesian frame does not have satisfactory information for locally resolving ambiguity. The rather modern approaches follow global way of thinking and apply Genetic Algorithms or similar evolutionary methods requiring huge computational power. The here presented approach is a compromise between these essentially different cases. For non-singular points it applies a fast algorithm to the differential solution, while near and in the singularities the Complex Algorithm combining the primary (that is tracking the prescribed data as precisely as possible) and secondary (complementary aspects applied in ambiguity resolution) requirements in an efficient way. The method is illustrated by calculations for particular trajectories in the case of a 6 DOF robot arm.

On the Placement of Serial Manipulators

2000 ◽  
Author(s):  
Karim Abdel-Malek ◽  
Wei Yu
Keyword(s):  
Cost Function ◽  
Inverse Kinematics ◽  
Inverse Kinematic ◽  
Working Environment ◽  
Robot Arm ◽  
Serial Manipulators ◽  
Surface Patches ◽  
Numerical Formulation ◽  
Fixed Reference ◽  
Position And Orientation

Abstract Criteria and implementation for the placement robot manipulators with the objective to reach specified target points are herein addressed. Placement of a serial manipulator in a working environment is characterized by defining the position and orientation of the manipulator’s base with respect to a fixed reference frame. The problem has become of importance in both the medical and manufacturing fields, where a robot arm must be appropriately placed with respect to targets that cannot be moved. A broadly applicable numerical formulation is presented. While other methods have used inverse kinematics solutions in their formulation for defining a locality for the manipulator base, this type of solution is difficult to implement because of the inherent complexities in determining al inverse kinematic solutions. The approach taken in this work is based on characterizing the placement forcing a cost function to impel the workspace envelope in terms of surface patches towards the target points and subject to functionality constraints, but that does not require the computation of inverse kinematics. The formulation and experimental code are demonstrated using a number of examples.

scholarly journals Kinematic of the Position and Orientation Synchronization of the Posture of a n DoF Upper-Limb Exoskeleton with a Virtual Object in an Immersive Virtual Reality Environment

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1069
Author(s):  
Deyby Huamanchahua ◽  
Adriana Vargas-Martinez ◽  
Ricardo Ramirez-Mendoza
Keyword(s):  
Virtual Reality ◽  
Upper Limb ◽  
Human Performance ◽  
Early Stage ◽  
Inverse Kinematic ◽  
Virtual Object ◽  
Immersive Virtual Reality ◽  
Virtual Reality Environment ◽  
Upper Limb Exoskeleton ◽  
Position And Orientation

Exoskeletons are an external structural mechanism with joints and links that work in tandem with the user, which increases, reinforces, or restores human performance. Virtual Reality can be used to produce environments, in which the intensity of practice and feedback on performance can be manipulated to provide tailored motor training. Will it be possible to combine both technologies and have them synchronized to reach better performance? This paper consists of the kinematics analysis for the position and orientation synchronization between an n DoF upper-limb exoskeleton pose and a projected object in an immersive virtual reality environment using a VR headset. To achieve this goal, the exoskeletal mechanism is analyzed using Euler angles and the Pieper technique to obtain the equations that lead to its orientation, forward, and inverse kinematic models. This paper extends the author’s previous work by using an early stage upper-limb exoskeleton prototype for the synchronization process.

A Novel Vertical Lift Machine and its Precise Pose Control

2014 ◽  
Vol 989-994 ◽  
pp. 3105-3109
Author(s):  
Xiao Bo Liu ◽  
Xiao Feng Wei ◽  
Xiao Dong Yuan ◽  
Wei Ni
Keyword(s):  
Control System ◽  
Theoretical Analysis ◽  
Control Method ◽  
High Accuracy ◽  
Inverse Kinematic ◽  
Design Model ◽  
Pose Control ◽  
Vertical Lift ◽  
Position And Orientation ◽  
Control Principle

This paper deals with the design and theoretical analysis on a novel vertical lift machine which can vertically lift above 700 kg load up to 3.2 meters above the floor and located the load with high accuracy of position and orientation. Firstly the design model based on the installment demands of line-replaceable units (LRUs) is constructed. Then theoretical analysis including the number of degree of freedom of the lift machine, the inverse kinematic, the control principle, the lift platform pose error and the precise pose control method are conducted in the article. The validity of the design model and the effectiveness of the precise pose control system are confirmed by experiments using a prototype lift machine.

Alternative Inverse Kinematic Equations for General RRP and RRR Regional Structures of Manipulators

1996 ◽  
Author(s):  
Peregrine E. J. Riley
Keyword(s):  
Degrees Of Freedom ◽  
Joint Angle ◽  
Inverse Kinematic ◽  
Intersection Point ◽  
Degree Polynomial ◽  
Six Degrees Of Freedom ◽  
Common Intersection ◽  
Position And Orientation ◽  
Spatial Positioning ◽  
Orientational Structure

Abstract Many manipulators with six degrees of freedom are constructed with two distinct sections, a regional structure for spatial positioning, and an orientational structure having a common intersection point for the joint axes. With this arrangement, inverse kinematic solutions for position and orientation may be found separately. While solutions for general three link manipulators have been available since the work of Pieper in 1969, this paper presents new forms of the inverse kinematic equations for general RRP and RRR regional structures. Cartesian coordinates of the F-surface (generated by movement of the outer two joints) together with the outer joint angle are used as the equation variables. In addition, a second degree polynomial approxiamation of the equation may be used for quick iteration to a solution. It is hoped that these new equations will be useful by themselves and in workspace regions where solutions using equations in terms of the joint variables are numerically inaccurate or impossible.

Analysis of the Grasp Planning Method for Manipulation of BH-4 Dextrous Hand

2007 ◽  
Author(s):  
Weidong Guo ◽  
Mileta M. Tomovic ◽  
Jiting Li
Keyword(s):  
Coordinate System ◽  
Inverse Kinematic ◽  
Planning Method ◽  
Experimental Result ◽  
Robot Arm ◽  
Grasp Planning ◽  
Physical Prototype ◽  
Dexterous Hand ◽  
Dextrous Hand ◽  
Kinematic Solution

The paper presents method for planning robotic dexterous hand grasping task using example of the Beihang University’s BH-4 dexterous hand. The grasping planning method is devised through modeling and simulation and experimentally verified using physical prototype. The paper presents the method for forward and inverse kinematic solutions of the BH-4 robot 4-DOF finger, including transformation matrix between the palm coordinate system and the finger base coordinate system. In addition, the method of the idiographic manipulation is presented using example of ball grasping. The simulation results and physical experiment verify that the inverse kinematic solution is correct, and kinematic grasping and operating planning is valid and feasible. Finally, the experiment with the complex system integrated robot arm with dexterous hand is carried out. Experimental result shows that the more complicated grasping task can be done by a dexterous hand integrated in the robot arm system.

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.

Inverse Kinematic and Control Architecture of a Slave Manipulator for MR-Guided Brain Biopsy

2008 ◽  
Author(s):  
C. Raoufi ◽  
A. A. Goldenberg ◽  
W. Kucharczyk ◽  
H. Hadian
Keyword(s):  
Modular Design ◽  
Brain Biopsy ◽  
Inverse Kinematic ◽  
Robotic System ◽  
Control Architecture ◽  
Neurosurgical Procedures ◽  
Biopsy Needle ◽  
Mri Guided ◽  
Position And Orientation ◽  
And Control

In this paper, the inverse kinematic and control paradigm of a novel tele-robotic system for MRI-guided interventions for closed-bore MRI-guided brain biopsy is presented. Other candidate neurosurgical procedures enabled by this system would include thermal ablation, radiofrequency ablation, deep brain stimulators, and targeted drug delivery. The control architecture is also reported. The design paradigm is fundamentally based on a modular design configuration of the slave manipulator that is performing tasks inside MR scanner. The tele-robotic system is a master-slave system. The master manipulator consists of three units including: (i) the navigation module; (ii) the biopsy module; and (iii) the surgical arm. Navigation and biopsy modules were designed to undertake the alignment and advancement of the surgical needle respectively. The biopsy needle is held and advanced by the biopsy module. The biopsy module is attached to the navigation module. All three units are held by a surgical arm. The main challenge in the control of the biopsy needle using the proposed navigation module is to adjust a surgical tool from its initial position and orientation to a final position and orientation. In a typical brain biopsy operation, the desired task is to align the biopsy needle with a target knowing the positions of both the target in the patient’s skull and the entry point on the surface of the skull. In this paper, the mechanical design, control paradigms, and inverse kinematics model of the robot are reported.

Contour Object Generation Method for Object Recognition Using FPGA

2013 ◽  
Vol 7 (2) ◽  
pp. 182-189 ◽  
Author(s):  
M. Peña-Cabrera ◽  
◽  
V. Lomas-Barrie ◽  
I. López-Juárez ◽  
R. Osorio-Comparán ◽  
...  
Keyword(s):  
Parallel Structure ◽  
Robot Arm ◽  
Ann Model ◽  
Fpga Architecture ◽  
Object Contour ◽  
Field Programmable ◽  
Contour Information ◽  
Orientation Information ◽  
Position And Orientation ◽  
Artificial Neural Network Ann

The article presents a method for obtaining the contour of an object in real time from non-binarized images for recognition purpose. The contour information is integrated into a descriptive vector named BOF used by a FuzzyARTMAP Artificial Neural Network (ANN) model to learn the object and then recognize it later. In this way, it is possible to obtain a learning process regarding the location and recognition of parts; to communicate to a robot arm the position and orientation information of an object for assembly purposes. Other method to obtain contour using binarized images, is compared with the described method in this paper in order to implement and test both in a Field Programmable Gate Array (FPGA) architecture. Since an ANN can be implemented more efficiently in a parallel structure such as FPGA architecture can supply, it is desirable to implement an efficient algorithm for obtaining the object contour in the same way.

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