Questions tagged [manipulator]
manipulator is a device used to manipulate materials without direct contact.
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questions
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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.
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1answer
21 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), ...
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1answer
42 views
Visual-Positioning Method
I'm working on mobile manipulator and trying to do visual-positioning of the end-effector.
My camera will located around 1-2 meters from the robot.
I'm sure i cant use color tracking method because ...
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2answers
34 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 ...
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1answer
18 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?
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0answers
50 views
Converting from Modified to Standard Denavit Hartenberg
This is probably a noob question.
But as of right now I am having difficulty converting from the Modified DH to a Standard DH parameters for the Franka Emika Panda. I need standard because it allows ...
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1answer
32 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, $\vdash$...
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1answer
68 views
Robotic Manipulator 3-RRP v2
I recently asked a question about a 3-RRP manipulator but the only answer didn't work for my robot.
I would describe the manipulator as an arm that rotates around the shoulder over the x-y axis, the ...
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2answers
133 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 ...
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1answer
36 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 ...
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2answers
75 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?
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2answers
56 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} &...
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1answer
38 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 ...
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0answers
40 views
Why my kinematic diagram is not giving the same position and orientation while forward kinematics test?
I am sharing my matlab code so that you can also generate the simulation .
...
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1answer
69 views
DH Parameter for OpenManipulator X from Robotis
I try to solve forward kinematics problem for OpenManipulator X from Robotis by using standard DH convention. The figure and dimension of the robot like this pic
I try to find DH parameter and got ...
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2answers
30 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 ...
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2answers
86 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 ...
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0answers
30 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 ...
0
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1answer
124 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?
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1answer
84 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 ...
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1answer
26 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?
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0answers
17 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 ...
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2answers
306 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", ...
0
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1answer
84 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 ...
0
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1answer
191 views
Which motors are specifically used for UR3 (Universal robot arm) [closed]
I am looking for the specification of UR3, peak torque and rpm.
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2answers
367 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 ...
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0answers
102 views
Orientation problem between Gripper and Object ??
I am working on a pick and place project using ROS & MoveIt!, I wrote my own pick and place functions which generate grasp poses according to the pose of the object and then automatically picks. (...
0
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1answer
127 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 ...
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0answers
263 views
Developing world-frame Jacobian using product of exponentials [closed]
I am going through different texts (Spong Robot Modeling and Control, Murray Mathematical Introduction to Robotic Manipulations) and I am seeing different Jacobians developed for the same RRRP ...
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1answer
1k views
D(q) Inertia Matrix and the Jacobian Matrix
There is something I need to verify.
Say we have the following RPR robot manipulator.
The DH table
yields 3 rotational matrices:
\begin{equation}
R^0_1, R^0_2, R^0_3
\end{equation}
Using these ...
1
vote
1answer
96 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
271 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....
2
votes
1answer
244 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 ...
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vote
2answers
651 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 ...
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2answers
628 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 ...
2
votes
1answer
327 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
1answer
66 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 \...
1
vote
2answers
376 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 ?
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2answers
780 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
464 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 $M\ddot{\theta} + C\theta + G = \tau$ (...
0
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1answer
839 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 ...
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2answers
1k 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
167 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 ...
0
votes
1answer
442 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 ...
1
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1answer
597 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 ...
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2answers
628 views
Different methods to determine DOF: Chebychev-Kutzbach-Grubler method vs. Screw method
I'm familiar with Chebychev-Kutzbach-Grubler method to determine degree of freedom of a robot arm. But it seems this method fails to calculate the mobility of some parallel robots, as explained here.
...
1
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1answer
76 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 ...
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2answers
94 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 ...
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1answer
730 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 ...
0
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1answer
191 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 ...
