Questions tagged [manipulator]

manipulator is a device used to manipulate materials without direct contact.

Filter by
Sorted by
Tagged with
0
votes
2answers
51 views

What does "resolution of a sensor" mean? [closed]

I am studying robotics and I am focusing my attention on the sensors used on robot manipulators. I have seen that there a proprioceptive sensors, such as encoders, and exteroceptive sensors, such as ...
1
vote
2answers
79 views

Problem defining rotation matrix

I am studying robotic kinematics , and given the following manipulator with its D-H frames assigned: I have to find the rotation matrix $R_{e}^{2}$, which is the rotation matrix of frame $e$ with ...
0
votes
1answer
162 views

What is a simple way to assign frames to a robot manipulator using D-H convenction?

I am studying the forward kinematics for robot manipulators, and I am focusing on the Denavit Hartenberg convenction for assigning frames to the various joints of the manipulator. The problem is that ...
0
votes
1answer
21 views

How to use artificial potential function in manipulator path planning?

The artificial potential method always takes robot as a point, if the manipulator is 6 degrees of freedom, how to use this method in path planning while six links can avoid the collision.
0
votes
2answers
110 views

Model of two link rigid manipulator

I am working on parameter estimation of a rigid two-link manipulator as shown in the picture below. Unlike the cylindrical links shown in the above image, my robot has links of oval shape. So the ...
0
votes
1answer
27 views

What is the difference between multi-link flexible manipulators and continuum robots?

I read the review[1] on flexible manipulators, the modeling method of multi-link(even if single-link) flexible manipulators seems very different from the continuum robots like OctArm(multi-section), ...
0
votes
1answer
27 views

Kinematics and dynamics analysis of manipulator in zero gravity

Is there any change in the analysis of kinematic and dynamic analysis of the manipulator which is working in zero gravity or microgravity?
0
votes
1answer
34 views

Articulated configuration

I'm reading Theory of Applied Robotics, 2nd edition by Jazar. The author states that articulated configuration has the following form: $R \vdash R \perp R$ where $R$ stands for revolute joint, $\vdash$...
2
votes
2answers
902 views

3-RRP manipulator robot

I'm having some issues with a planar manipulator I have to deal with. The first two moves are rotational and the third one is a prismatic one. The shoulder and elbow move around the X-axis, while the ...
1
vote
2answers
416 views

Number of inverse kinematics closed form solutions for ABB IRB 140

I've read that 6 dof manipulators give eight closed form solutions, according to a paper. What is the number of iK solutions for the ABB IRB 140? (last three axes intersect but there is a offset ...
0
votes
1answer
47 views

Definition of robotics manipulator?

I'm new to robotics, I don't understand the way wikipedia defines robotics manipulator. If there is no any direct contact how could the robot move things within his work envelope. In robotics a ...
0
votes
2answers
304 views

What is the degree of freedom of the following drone?

This might be a stupid question to ask here .i am confused whether the dof of this drone is 3 or 4?
4
votes
2answers
199 views

Calculating Error of Arm Manipulator

How can we calculate the error position of arm manipulator? Let's say we have a Transformation Matrix: $$\begin{bmatrix} R_{00} & R_{01} & R_{02} & x\\ R_{10} & R_{11} & R_{12} &...
0
votes
1answer
47 views

Fuzzy logic controller for controlling a four-bar linkage

I am trying to design a control system to move a joint of four bar linkage according to desired trajectory. A dc-motor is used to move the joint. Can fuzzy logic controller be used to solve this ...
1
vote
2answers
148 views

Effiecient computation of coriollis matrix

I want to perform kinodynamic motion planning on a 6DoF hybrid manipulator. I calculated mass matrix, coriollis matrix etc using the lagrangian method. The coriollis matirx was calculated symbolically ...
2
votes
1answer
245 views

Why do I need impedance control?

I am having a hard time understanding the impedance controller. I see that it looks at the manipulator as impedance and the environment as admittance. However, it is hard to grasp the concept and ...
1
vote
0answers
46 views

Task Space Control Parameters for 6-Dof Manipulator

I'm developing a Task Space controller based on speed for a Universal Robot 5. I've already calculated the Jacobian, position and rotation error for the classic control method: The method works fine ...
2
votes
1answer
2k views

What is the difference between the pose of a robot and the configuration of a robot?

Do "configuration" and "pose" means the same thing? If not what is the difference?
0
votes
1answer
54 views

Why does degree of freedom only consider continuous values?

In the book Modern Robotics Chapter 2 Configuration space, we are told that degrees of freedom only considers coordinates with real valued continuous range. Why is this the case?
1
vote
0answers
20 views

Control Algorithms for Kinesthetic Teaching

There are several algorithms for post-processing of kinesthetically demonstrated motions for manipulators learning a task. However, I have failed to find papers/research work on modeling the ...
2
votes
1answer
1k views

Symbolic Representaion of Links and Joints: How to sketch complex manipulators using simple symbols?

In some papers and books we can see that authors using symbols to represent robot arms. My question is, is there a convention for such sketches? If so could you provide a reference which shows how ...
5
votes
3answers
1k views

Computing the Jacobian Matrix -- chain rule?

I am learning about robot kinematics and the Jacobian matrix, and I'm trying to understand how to compute the Jacobian matrix given a kinematic chain, such as a robot arm. I understand the theory ...
1
vote
2answers
528 views

Validation of dh parameters

I am working on a concept of robotic arm for which I have fixed DH frames and parameters. Is there any way to validate the correctness of DH parameters and frames ?
2
votes
2answers
618 views

Inverse Kinematics - How to only find a unique joint angle solution in 4 dof robot?

I have to develop an algorithm to determine the necessary joint angles to achieve a desired TCP position and orientation in a 4 joint manipulator. I have come across a concept called "degeneracies", ...
2
votes
1answer
399 views

Significance of link length ratio in serial manipulator

I am formulating a problem to optimize link lengths of 3R serial manipulator shown below : I do not assume any explicit relationship between the link lengths, but in one of the papers (http://www....
0
votes
1answer
136 views

D-H parameters verification

This robot has 2 revolute joints in advance then one cylindrical joint, then one revolute joint, then another cylindrical joint, then three revolute joints at the end. There is no D-H table for that ...
3
votes
2answers
761 views

Understanding MoveIt! and OMPL more deeply

I wanted to know the actual mathematics behind the path planners MoveIt! uses for manipulators from OMPL. I tried to look into source codes but couldn't get enough details. I wish to know: How cost ...
5
votes
3answers
593 views

Proportional controller error doesn't approach zero

I'm reading this pdf. The dynamic equation of one arm is provided which is $$ l \ddot{\theta} + d \dot{\theta} + mgL sin(\theta) = \tau $$ where $\theta$ : joint variable. $\tau$ : joint torque ...
0
votes
1answer
305 views

Which motors are specifically used for UR3 (Universal robot arm) [closed]

I am looking for the specification of UR3, peak torque and rpm.
0
votes
1answer
253 views

zero-g mode for UR10 gravity compensation

I would like to freely move my UR10 arm in response to an external force, just like the zero-g mode for Baxter robot, which can be activated by holding its wrist. The Baxter documentation on zero-g ...
2
votes
1answer
389 views

Dynamics of a robot manipulator with a force acting on the end-effector

I have this exercise The dynamic model is $B(q)\ddot{q}+S(q,\dot{q})\dot{q}=\tau+\tau_k$ Where $B(q)$ is the inertia matrix, $S(q,\dot{q})\dot{q}$ are the centrifugal and Coriolis terms, $\tau$ is ...
1
vote
1answer
115 views

Urdf as a way to model dynamics?

Since urdf format serves the purpose of kinematic model but also extends for dynamical properties such as mass,moment of inertia and centre of masses, can it be considered a viable dynamical model of ...
2
votes
1answer
538 views

Optimization of link lengths for 3R serial manipulator

I am trying to formulate an optimization problem for determining link lengths of 3R manipulator shown in picture below, Following are the constraints, Robot arm should be reachable at point x = 100, ...
1
vote
2answers
1k views

How to check reachability of manipulator to a point?

I have written a MATLAB code for inverse kinematics of 3R robotic arm, which returns value of joint angles for given link lengths and end effector position and orientation. But if location of point is ...
1
vote
2answers
1k views

Why does the Denavit-Hartenberg representation fail to capture the length of the last link in my model?

The length of the last link (1.73) of my model (of a human finger) is not represented in any of the parameters that I calculated using the Denavit-Hartenberg algorithm, which I think can't be right. I ...
1
vote
1answer
88 views

How can serial manipulator have unique condition number for given end effector position?

I am reading about Condition Number which is considered as measure of manipulability of robotic arm, it is defined as $$ k = \parallel J \parallel \parallel J^{-1} \parallel $$ Where, $$ \parallel J \...
0
votes
1answer
1k views

forward and inverse kinematics of arm

I'm trying to figure out to a problem with a planar manipulator. The manipulator has a base effector and L1 and L2 with 3 joints. Question: INVERSE KINEMATICS Given the ...
3
votes
1answer
484 views

Human arm inverse kinematics

Hi I want to implement an human arm robot and a task such as moving a glass between two points using Robotic Toolbox for Matlab by Peter Coorke. I'm a student and I'm a newbie in this kind of things ...
1
vote
2answers
1k views

how to make a configuration space of a robot manipulator?

How to make a configuration space of a robot manipulator from a work space ? it's robot manipulator is 3 degree of freedom. Is a robot manipulator with more degrees of freedom the same process ?. Do ...
2
votes
1answer
559 views

Euler-Lagrange Dynamic model

I'm working on a masters thesis and need to calculate Mass inertia matrix ($M$), Coriolis/Centrifugal matrix ($C$), and the gravity matrix ($G$) in the equation $M\ddot{\theta} + C\theta + G = \tau$ (...
1
vote
2answers
2k views

Calculating the singular configuration of a 3 revolute joint manipulator

I would really appreciate it if somebody could help me calculate the singular configuration of this simple manipulator I am confused since J is a 2x3 matrix and I cannot simply calculate the ...
0
votes
1answer
621 views

DH parameters of a PUMA-type manipulator

I'm struggling to find the DH parameters for this PUMA-type manipulator that yield the same results as the author (1): The way I'm checking if the parameters I have are correct is by comparing the ...
0
votes
1answer
218 views

Is it possible to control joint torque using the position input and torque feedback?

So I am working with a UR10 manipulator which doesn't have a direct torque interface. However, it provides torque/velocity/position feedback for each joint as well as position/velocity interfaces for ...
9
votes
4answers
2k views

Implementing a torque-controlled method on a position-controlled robot

I am working with a position-controlled manipulator. However, I want to implement a torque-controlled method on this robot. Is there any way to convert a torque command to a position command? I try ...
1
vote
2answers
3k views

Difference between Degrees of Freedom (DOF) and Degrees of Motion (DOM)

What is a difference between degrees of freedom (DOF) and degrees of motion (DOM)? I know that DOF is the number of independent movements a manipulation arm can make and robot system can have max 6 ...
1
vote
1answer
81 views

Robot Graphical Representation in Real Time

I'm working with a robot intended to be placed in a tele-echography environment. To control the robot I'm using a 6D space mouse that control each degree of freedom of the robot. However, since the ...
0
votes
2answers
131 views

Are scissors what I want for moving straight up and out?

I'm a programmer. I had a tiny amount of experience building robots in college a few years ago, but haven't done anything since. I'd like to build a robot that can move around my house, pick items up ...
0
votes
1answer
228 views

How to use RL (Robotics Library) with Xcode?

I came across RL to program robotic manipulators. But according to the website, currently supported websites are Ubuntu and Windows only. Since Ubuntu and Mac OS are based on UNIX kernel, is it ...
1
vote
2answers
277 views

Optimal trajectory for manipulators using optimal control

I'm trying to implement direct-multiple shooting method to my problem. ...
0
votes
1answer
1k views

Dynamics of a 3R planar robot manipulator,matrices M(q),C(q,q') and G(q)

The dynamics equation is T=M(q)*q''+C(q,q')*q'+G(q). Can somebody provide me with the M(q), C(q,q') and G(q) matrices of a 3R manipulator with link mass,length and rotational inertia m_i, l_i and ...