Approach to Positioning Links of the Manipulator Using Neural Networks

2019 ◽  
Vol 20 (12) ◽  
pp. 732-739
Author(s):  
P. A. Smirnov ◽  
R. N. Yakovlev
Keyword(s):  
Neural Networks ◽  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Linear Equations ◽  
Target Point ◽  
Positioning Systems ◽  
Solution Methods ◽  
Inverse Kinematics Problem ◽  
Manipulator Link ◽  
Robotic Devices

This paper considers development of positioning systems for manipulator links to solve the forward kinematics problem (FKP) and inverse kinematics problem (IKP). Here we study a robotic manipulator with four degrees of freedom. It should be noted, that one of the relevant research problems of modern modular robotic devices consists in the lack of the universal algorithms, that would ensure kinematics problem recalculations in the cases of reconfigurations of the whole system. Challenges, the researchers are facing with when solving this problem, have to do with geometrical and non-linear equations (trigonometric equations), finding of inverse matrix of the Denavit—Hartenberg presentation, as well with other problems, such as multiple solutions when using the analytical approach. Common mathematical solutions of the inverse kinematics problem, such as geometric, iterative and algebraic ones, may not always lead to physically appropriate solutions. It’s also noteworthy, that, trying to introduce physical solutions for the manipulator, we need to take into account, that the number of calculation formulas increases, what, in turn, causes further computing power consumption increase. If the manipulator acquires additional degrees of freedom, analytical modeling becomes virtually impossible. One of relevant inverse kinematics solution methods consists in implementation of neural networks to that end. To solve this problem various sources were analyzed, considering alternative ways of target point discovery. Considering the analyzed papers, we propose to use a perceptron. Before training the network, we compose an algorithm, calculating the Denavit—Hartman presentation matrix and check for correctness of target point reach by the terminal manipulator link. We did calculations for a thousand positions of manipulator and object in the environment, fed to the neural network. When solving FKP we obtain object coordinates as network output, whereas in the case of IKP — manipulator link angles. We present kinematic scheme testing results, as well a control scheme for a manipulator with four degrees of freedom.

Kinematics of a Fully-Decoupled Remote Center-of-Motion Parallel Manipulator for Minimally Invasive Surgery

2012 ◽  
Vol 6 (2) ◽  
Author(s):  
Chin-Hsing Kuo ◽  
Jian S. Dai
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Invasive Surgery ◽  
Inverse Kinematics ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Surgical Instruments ◽  
End Effector ◽  
Minimally Invasive Surgical ◽  
Inverse Kinematics Problem

A crucial design challenge in minimally invasive surgical (MIS) robots is the provision of a fully decoupled four degrees-of-freedom (4-DOF) remote center-of-motion (RCM) for surgical instruments. In this paper, we present a new parallel manipulator that can generate a 4-DOF RCM over its end-effector and these four DOFs are fully decoupled, i.e., each of them can be independently controlled by one corresponding actuated joint. First, we revisit the remote center-of-motion for MIS robots and introduce a projective displacement representation for coping with this special kinematics. Next, we present the proposed new parallel manipulator structure and study its geometry and motion decouplebility. Accordingly, we solve the inverse kinematics problem by taking the advantage of motion decouplebility. Then, via the screw system approach, we carry out the Jacobian analysis for the manipulator, by which the singular configurations are identified. Finally, we analyze the reachable and collision-free workspaces of the proposed manipulator and conclude the feasibility of this manipulator for the application in minimally invasive surgery.

Dynamics of redundant robots – inverse solutions

Robotica ◽  
1986 ◽  
Vol 4 (4) ◽  
pp. 263-267 ◽  
Author(s):  
Ronald L. Huston ◽  
Timothy P. King
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Solution Algorithm ◽  
Redundant Robot ◽  
Redundant Robots ◽  
Revolute Joints ◽  
Inverse Kinematics Problem ◽  
Inverse Solutions ◽  
Natural Dynamics ◽  
Least Energy

SUMMARYThe dynamics of “simple, redundant robots” are developed. A “redundant” robot is a robot whose degrees of freedom are greater than those needed to perform a given kinetmatic task. A “simple” robot is a robot with all joints being revolute joints with axes perpendicular or parallel to the arm segments. A general formulation, and a solution algorithm, for the “inverse kinematics problem” for such systems, is presented. The solution is obtained using orthogonal complement arrays which in turn are obtained from a “zero-eigenvalues” algorithm. The paper concludes with an assertion that this solution, called the “natural dynamics solution,” is optimal in that it requires the least energy to drive the robot.

A Fuzzy Algorithm to Study the Inverse Kinematics Problem of a Serial Manipulator

2015 ◽  
Vol 783 ◽  
pp. 77-82
Author(s):  
Francesco Aggogeri ◽  
Nicola Pellegrini ◽  
Riccardo Adamini
Keyword(s):  
Inverse Kinematics ◽  
Linear Equations ◽  
Rigid Bodies ◽  
Robust Performance ◽  
Serial Chain ◽  
Interactive Algorithm ◽  
Inverse Kinematics Problem ◽  
Transcendental Functions ◽  
Computationally Expensive ◽  
Non Linear Equations

This paper presents a fuzzy logic to solve the inverse kinematics problem. As the complexity of robot increases, obtaining the inverse kinematics solution requires the solution of non linear equations having transcendental functions are difficult and computationally expensive. This study focuses on a serial manipulator modelled as a serial chain of rigid bodies connected by joints. A new fuzzy interactive algorithm is developed and the effectiveness is compared with other methods on a SCARA robot. It converge in all the developed simulations showing a robust performance.

Impedance Control: An Approach to Manipulation: Part II—Implementation

1985 ◽  
Vol 107 (1) ◽  
pp. 8-16 ◽  
Author(s):  
Neville Hogan
Keyword(s):  
Feedback Control ◽  
Inverse Kinematics ◽  
Control Algorithm ◽  
Degrees Of Freedom ◽  
Impedance Control ◽  
Dynamic Interaction ◽  
End Point ◽  
Inverse Kinematics Problem ◽  
Theoretical Reasoning ◽  
Redundant Actuators

This three-part paper presents an approach to the control of dynamic interaction between a manipulator and its environment. Part I presented the theoretical reasoning behind impedance control. In Part II the implementation of impedance control is considered. A feedback control algorithm for imposing a desired cartesian impedance on the end-point of a nonlinear manipulator is presented. This algorithm completely eliminates the need to solve the “inverse kinematics problem” in robot motion control. The modulation of end-point impedance without using feedback control is also considered, and it is shown that apparently “redundant” actuators and degrees of freedom such as exist in the primate musculoskeletal system may be used to modulate end-point impedance and may play an essential functional role in the control of dynamic interaction.

Neural networks and the inverse kinematics problem

1993 ◽  
Vol 4 (1) ◽  
pp. 43-66 ◽  
Author(s):  
H. Jack ◽  
D. M. A. Lee ◽  
R. O. Buchal ◽  
W. H. Elmaraghy
Keyword(s):  
Neural Networks ◽  
Inverse Kinematics ◽  
Inverse Kinematics Problem

A complete analytical solution to the inverse kinematics of the Pioneer 2 robotic arm

Robotica ◽  
2005 ◽  
Vol 23 (1) ◽  
pp. 123-129 ◽  
Author(s):  
John Q. Gan ◽  
Eimei Oyama ◽  
Eric M. Rosales ◽  
Huosheng Hu
Keyword(s):  
Analytical Solution ◽  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Robotic Manipulators ◽  
Robotic Arm ◽  
Effective Solution ◽  
Robotic Arms ◽  
Unstructured Environment ◽  
Inverse Kinematics Problem

For robotic manipulators that are redundant or with high degrees of freedom (dof), an analytical solution to the inverse kinematics is very difficult or impossible. Pioneer 2 robotic arm (P2Arm) is a recently developed and widely used 5-dof manipulator. There is no effective solution to its inverse kinematics to date. This paper presents a first complete analytical solution to the inverse kinematics of the P2Arm, which makes it possible to control the arm to any reachable position in an unstructured environment. The strategies developed in this paper could also be useful for solving the inverse kinematics problem of other types of robotic arms.

Inverse Kinematics Solutions for General Spatial Linkages

1987 ◽  
Author(s):  
M. Tucker ◽  
N. D. Perreira
Keyword(s):  
Inverse Kinematics ◽  
Robot Control ◽  
Degrees Of Freedom ◽  
General Purpose ◽  
Inverse Solution ◽  
Six Degrees Of Freedom ◽  
Inverse Kinematics Problem ◽  
Spatial Linkages ◽  
Pseudo Inverse ◽  
Solution Techniques

Abstract A procedure for obtaining solutions to the general inverse kinematics problem for both position and velocity is presented. Solutions to this problem are required for improved robot control and linkage synthesis. The procedure requires obtaining the inverse of the actual robot linkage Jacobian. A procedure to detect the presence of singularities in the Jacobians and their causes are given. Inverse solution techniques applicable to robots with less than, equal to, or greater than six degrees of freedom and their implementation to robots with various types of singularities is outlined. For each case, the implementation of both the complete Moore-Penrose inverse and a robot specific pseudo inverse are included. Although it is not necessary to use the complete Moore-Penrose inverse on any particular robot, it can be used to obtain generic inverse routines for general purpose applications.

Inverse Kinematics of Serial-Chain Manipulators

1996 ◽  
Vol 118 (3) ◽  
pp. 396-404 ◽  
Author(s):  
Hong-You Lee ◽  
Charles F. Reinholtz
Keyword(s):  
Inverse Kinematics ◽  
Minimum Degree ◽  
Complete Solution ◽  
Linear Equations ◽  
End Effector ◽  
Serial Chain ◽  
Inverse Kinematics Problem ◽  
Univariate Polynomials ◽  
General Geometry

This paper proposes a unified method for the complete solution of the inverse kinematics problem of serial-chain manipulators. This method reduces the inverse kinematics problem for any 6 degree-of-freedom serial-chain manipulator to a single univariate polynomial of minimum degree from the fewest possible closure equations. It is shown that the univariate polynomials of 16th degree for the 6R, 5R-P and 4R-C manipulators with general geometry can be derived from 14, 10 and 6 closure equations, respectively, while the 8th and 4th degree polynomials for all the 4R-2P, 3R-P-C, 2R-2C, 3R-E and 3R-S manipulators can be derived from only 2 closure equations. All the remaining joint variables follow from linear equations once the roots of the univariate polynomials are found. This method works equally well for manipulators with special geometry. The minimal properties may provide a basis for a deeper understanding of manipulator geometry, and at the same time, facilitate the determination of all possible configurations of a manipulator with respect to a given end-effector position, the determination of the workspace and its subspaces with the different number of configurations, and the identification of singularity positions of the end-effector. This paper also clarifies the relationship between the three known solutions of the general 6R manipulator as originating from a single set of 14 equations by the first author.

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