Questions tagged [manipulator]

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

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How to calculate Exponential coordinates of end_effector from Transformation matrix

I want to know Exponential coordinates of end effector $\text{S}\theta$(6-vector) from end effector transformation matrix. I calculated the transformation matrix of the end effector from the forward ...
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Is this motion possible for this manipulator?

I'm currently solving the exercises of Modern Robotics book. I came across this problem but it is not clear to me how to approach it. I computed the analytic Jacobian which is $$ \begin{bmatrix} \dot{...
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Pose of the end-effector

I am trying to get the pose of the end-effector. I have attached the picture. I am stuck. I wrote the transformation matrices - I am not sure how to move forward next. How do I find the end-effector ...
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Inverse Kinematics with Orientations

Let's say I have a robot consisting of a base $B$ and a manipulator $M$. The pose of the manipulator can be expressed as the transformation matrix $T_{BM}$. I also have a goal $G$ which I want to move ...
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Newton-Euler Inverse Dynamics by Screw

I paste this algorithm from textbook Modern Robotics P294 in chapter 8: This is coordinate invariance of Newton-Euler equations. In the textbook, they use the ...
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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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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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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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how to manipulate arm robot? [closed]

I want to make a robot arm with a gripper that can go to any x y z coordinates near it. the robot itself will be simple just servo motors and Arduino but I don't know how to make reach the desired ...
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definition of self motion

From my understanding, self motion refers to a set of joint velocities which doesn't cause any cartesian motion on the end-effector. Here, by motion it is meant both linear and angular components or ...
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Sinusoidal trajectory of each cartesian coordinate for the end effector

Consider a 7-DOF robotic manipulator. I want the end effector to follow a predefined trajectory and suppose I care only about the position and not about the orientation. So, the rotation part of the ...
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How to calculate potential enegy of manipulator?

I'm trying to obtain dynamics of a 4 DOF robot. Firstly, I calculated all Transformation matrices and Jacobians. While solving Lagrangian there is two main things one is kinetic energy and the other ...
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Is it possible to control a 5 DOF manipulator in the 6 DOF Task Space?

I am referring to pre-computed torque control techniques that are based on the Task Space dynamic model. Maybe by using pseudo-inverse for the Jacobian and the task space inertia matrix ? Cheers, ...
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How to calculate displacement of the end effector by the yaw, pitch, and roll in the spherical joint?

For planar robots, we can calculate how small changes in the angle of each joint corresponds to the displacement of the end effector, by constructing a jacobian consisting of cross products between ...
Lenny White's user avatar
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Design optimization method using indices

There are several methods like manipulability and conditioning index for design optimization kinematics performance, but these methods rely on the singular values of the jacobian matrix. I described ...
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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 ...
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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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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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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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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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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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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 ...
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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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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 ...
Abdullah Nazir's user avatar
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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 ...
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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 ...
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Pick and place using only vision information and forward kinematics [closed]

Is it possible to do pick and place tasks using only forward kinematics and object detection information from a camera? I want to avoid having to do inverse kinematic calculations for my robot. Is ...
M Fadli Masykuri's user avatar
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Short distance ball transport

I'm looking for a way to transport balls (diameter 50mm) 220 mm up with over a slope with a length of 120 mm. Currently I'm considering the usage of a belt system but I cannot seem to find a good belt ...
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How to model the Cable composites in Mujoco Physics Simulation engine

How to name the cable composite in mujoco, also how to add equality constraint to the end of the cable with another body ?
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Why is admittance control better than impedance control for huma robot collaboration?

I have seen many papers that use admittance control for human robot collaboration but no one tells why admittance is the choice and not impedance. Is it something very trivial that I should know or ...
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Transformation Pose

Hi I am doing a transform from the object to the base_link the orientation seems to be right but the positioning is wrong.Here is my code. i had to change the translation values as when i move foward ...
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Where can I find 6 DOF manipulator packages for gazebo?

Hello. Where can I find 6 DOF manipulator with a 4-wheel mobile base packages for gazebo? Thanks. Originally posted by NickRos on ROS Answers with karma: 1 on 2023-02-14 Post score: 0
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How to add gripper to robot arm and plan according to the end effector on Moveit

Hello! I am simulating for a university project, the Elfin 5 robot arm which package can be found here along with a gripper which package is found here. Being new to Moveit, I am finding trouble to ...
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The weight on position constraint for link is near zero. Setting to 1.0

Hi, While trying to move a robotic manipulator to a new pose (using MoveIt!), in order to move to the Next Best View of the manipulator's workspace using the YAK package, I repeatedly get this warning ...
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REQUIRED process [open_manipulator_dynamixel_controller-2] has died!

I just tried to operate open manipulator system by using two motor(MX-106). When I launch that code, the following error occur. ...
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Generating IK solution for use in MoveIT for 5 DOF arm

I am working on a custom 5 DOF arm(image at the bottom). I have generated the URDF, the MoveIt configs etc for it. I want to have the basic IK, planning and collision detection features of MoveIt. ...
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ROS Answers SE migration: manipulator

hi there. i want to make a manipulator either 6 DOF or 3 DOF. is there any packages/tutorial available for ROS indigo version ???? Originally posted by Arpitsoni on ROS Answers with karma: 9 on 2016-...
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Recommendations for a hardy, IP67 arm

Hi, I'm looking for an IP67 arm for a mobile robot in a harsh environment. Some other wishes are: ROS compatability Small controller (must fit on a ~900mm x 900mm platform) Reach >500mm At least 5 ...
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Best way to use Moveit for teleoperation?

I've seen this topic discussed a bit here, and on the MoveIt! mailing list here and here, but those conversations are pretty old now and I'm wondering if there is a clearer answer now. I have a 7 DOF ...
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UR5 - Gazebo Joint Position controller

Dear all, I need to simulate a velocity control of a UR5 robot in Gazebo + ROS. But current packages of UR only has a joint trajectory controller, But I want to control individual joint velocities ...
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what could be the process flow for trajectory planning of 6DOF manipulator using arduino?

hi, i want to make exactly what this video shows - https://www.youtube.com/watch?v=IfP6J9Bxt2w . can anybody tell me how to interlink arduino with ros? which tutorial i need to study? i've just ...
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How can I do tabletop manipulation with a 5DOF arm?

Hi, if i want to do my robotic arm to recognition an object using camera and get it there are missing steps for me like that Do i get the kinematics and inverse kinematics of my arm by Kinematic ...
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Moving Manipulator in Gazebo or Rviz

Hi, I'm relatively new to ROS, and I need to simulate a robotic arm to track velocities and avoid obstacles. I've written all the mathy algorithms down to find the inverse kinematics that make the ...
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Manipulator arm Gazebo

Hello. I want to simulate a manipulator arm on a mobile robot (URDF) in Gazebo. What package I must use? I saw that the arm_navigation package is used in RVIZ. Can I use this package in Gazebo? Could ...
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an example of a robotic arm in ROS

Hello, I have to do a small project in which I must simulate a robotic arm. I found ROS software very interesting and I would like to use it in order to complete my project. However, I spent a lot of ...
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DH parameters of a serial manipulator RRRRRR

I am trying to find the forward kinematics of this manipulator in the picture using DH notation. All of the joints are rotational. I managed to get to the third joint. The parameter table is below. ...
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When assigning frames in Denavit-Hartenberg (DH) parameters, where do I put the frame on end effector?

I have a simple question, for the last link (end effector) I need to estimate the parameters but when I put the reference frames in the center of the end effector, I just don't know. Last link (end ...
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Question about Impedance control in The Modern Robotics: Mechanisms, Planning, and Control

Impedance equation In 11.7.1 section $\tau = J^T(\theta)(\hat{\Lambda}(\theta)\ddot{x}+\hat{\eta}(\theta,\dot{x}) - (M\ddot{x}+B\dot{x} + Kx))$ is actually means $\tau = J^T(\theta)(\hat{\Lambda}(\...
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Why the robot is not at the zero configuration

As part of my testing, I was using Kuka's arm to test some kinematic controllers. In the picture below, when the arm is spawned in Gazebo, the positions of the joints are zero (i.e. obtained from <...
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For robot manipulators what is the relationship between angular velocity and time derivative of quaternions?

For a robot manipulator with joint angles $\theta$, the well-known relationship is $$\omega = J_\omega(\theta)\dot{\theta}.$$ What if the angular velocity is represented as the time derivative of ...
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