Questions tagged [robotic-arm]

The arm tag is intended to be used for questions relating to robotic arms from, small hobby arms with only 1 or 2 degrees of freedom to large industrial robots with complex joint assemblies. For the ARM CPU, use the tag arm-cpu.

82 questions with no upvoted or accepted answers
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1answer
811 views

Poor accuracy of hand eye calibration when using vanilla Tsai's method

I’m working on the hand eye calibration for the robotic arm. I attached the camera near the tip of the robot (or end effector) and took around 40 pictures of an asymmetric circles pattern. I ...
3
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1answer
36 views

Calculation of error, based on camera images

I am trying to measure the precision error of a gripper that is mounted to the flange of a 6 DOF industrial robot. The gripper-design is rather complex, therefore we would like to make sure it is ...
2
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1answer
57 views

Jacobian of a planar manipulator with 4 links

I have a mobile manipulator that moves on the plane. The base moves in SE(2) and the manipulator is also planar with 4 links. The mobile base will be a differential drive robot and its motion is ...
2
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2answers
546 views

Finding correct RPY for approaching a known point on a plane

I have a robot with 6 DOF that I want to use to grab a hanging sheet at a specific point near its edge. The grip needs to be perpendicular to the edge and co-planar with the point of course. I have ...
2
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0answers
335 views

Holonomic constraint forces using Lagrange multipliers

Consider a multibody robotic system with Lagrangian $ L = \dot{q}^{T}M\dot{q} + V $ and equations of motion of the form $$M(q)\ddot{q}+C(q,\dot{q})\dot{q}+A^{T}(q)\lambda+N(q)=0 $$ where $N=\frac{\...
2
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2answers
220 views

Tool calibration- orientation

I'm currently working on calibration of robot tool. I have found some simple methods to get the tool centre point. But I'm sure how to get the tool orientation wrt the robot's tip (the point where the ...
2
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0answers
259 views

Inertia Tensors in 3D objects for robot dynamics

I'm trying to obtain the dynamics of a 6DOF robot. Firstly, I calculated the combined centres of mass (between each link and the respective actuator) in order to calculate the gravity term, since it ...
2
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0answers
69 views

How unique are Quarternions and what about the sign?

I want to track a robot's orientation in space and wanted to choose quaternions for their many advantages. However I have a few questions that I haven't found to be solved anywhere. The method I use ...
1
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0answers
18 views

How to calculate twist and wrench in local and global frames

I am rather new to screw theory and also lost in robotics books' formulas. we have a simulator of a robot arm within Mujoco physics engine and I'm wondering how I can calculate wrench and twist in the ...
1
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1answer
25 views

Self motion with multiple constraints

I am trying to control a 7 DOF robot (a Franka Panda). I use jacobian based control (resolved rate motion control) to generate a joint trajectory from a cartesian trajectory. My contraints for the ...
1
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1answer
41 views

Verifying DH parameters. Unexpected Output

There is a rotating base joint #1 with z/joint axis pointing up and atop sits and arm with 3 z/joint axis facing away from the viewer. The elbow joint F2 has a kink before it of 90 degrees measuring ...
1
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0answers
26 views

Link collision avoidance for redundant manipulator

I am trying to have my robot arm follow a trajectory while avoiding collisions between obstacles and the robot links. The way I go about it is to find the closest point on the robot arm, and treat the ...
1
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0answers
39 views

PD controller tuning for flexible joint robotic arm

I am trying to tune the gains of my PD controller for a single axis flexible joint robot. The controller output is the motor torque. My question is: how can i tune the PD gains if the output (torque) ...
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0answers
20 views

What is canonical grasp?

What is a canonical grasp and how is it different from normal/other grasp? I've searched through internet and forums but haven't found any answers.
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0answers
16 views

How To Run the kuka_experimental program on github In RViz?

I have installed Ubuntu 14.04 and installed ROS Indigo in order to run the kuka_experimental source code which can be found on github. I have built the catkin workspace and compiled the ...
1
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0answers
18 views

Increasing suction force

I'm trying to increase the suction force of the end effector in a pick and place system. Is it a good idea to add an extra vacuum pump and put it in parallel? AFAIK, having an extra pump in parallel ...
1
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1answer
48 views

Speeding Up UR5e Joint Movement

I am working with a Universal Robots UR5e. I am attempting to do a simple back and forth movement of 60 Degrees with Wrist 2, operating at 2 Hz (back and forth in 0.5s). Looking at the Joint Limits, ...
1
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1answer
163 views

Controlling Actuated Robot Hand in Underactuated Manner

We have an allegro hand in our robot, and it is in actuated behavior. In other words, each joint is controlled one or more than one actuator, that is motor. There are 3 actuators for each finger, ...
1
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0answers
38 views

Inverse Kinematics of Puma 566 giving low angle results with DH convention

I am new at the robotics area, and i need to deliver an activity until this week in my college based to solve the inverse kinematics problem from an article that doesn't have any code done, and after, ...
1
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1answer
175 views

UR5 Visual servoing(image based, eye in hand)

I am implementing IBVS on a UR5 using ROS. The algorithm works very well in linear X, Y and Z and omega Y. When I try to add a fifth axis(omega X or Omega Z), the robot jerks heavily and goes into ...
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0answers
44 views

Any way to program a robot remotely?

So Udacity, Kuka and KIT are/were offering a Kuka challenge. Basically, the participants got to write code and run it remotely on a Kuka robot based in the KIT labs in Germany and submit their code ...
1
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1answer
157 views

3D Inverse Kinematics Jacobian Construction

I am following this article: Overview of Jacobian IK From the link, an example says: O is a pose vector which represents the initial orientation of every joint And following this, it gives an ...
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0answers
111 views

robot Hand Eye Calibration problem

I am trying to understand the implementations and the relative performance of various classical and new Hand-eye calibration approaches. Note: The following discussion assumes implementations are in ...
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0answers
67 views

Defining C-space state for an arm in OMPL

I'm very new to Robotics, so please bear with my ignorance about the subject. That said, I'm trying to use Open Motion Planning Library (OMPL) to set up the configuration space for a robotic arm ...
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0answers
554 views

URScript - how to get the actual TCP pose in tool space coordinate system?

I am writing a simple script for universal robots UR10 robotic arm. I am trying to find a way to to see if the tool current position is outside of a 3D bounding box. the 3D bounding box is defined ...
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0answers
51 views

Tracking object in realtime using depth image stream from a RGBD camera

I have an Intel RealSense camera which can stream RGB and depth image. Using those information I want to track an object moving on a table top. More specifically, I want to know position $(x,y)$ and ...
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0answers
169 views

How to create a .urp for universal robots?

The polyscope platform of Universal Robots saves programs as *.urp. They are very different to urscrips. Is there a way to create such files without polyscope?
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0answers
26 views

Torque Disturbance Observer for Manipulator Arms

Is there a tutorial/guide apart from the research papers ( paper 1 and paper 2 ), for implementation of torque disturbance observers on multi-DOF robotic manipulators to determine sudden collision ...
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0answers
64 views

How to implement end effector orientation in generic IK solver

I am trying to script a basic, lightweight IK solver with a Jacobian Transpose method. I have gotten a basic script that reach the desired position very quickly. What I am not able to do is achieve a ...
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0answers
139 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. (...
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0answers
151 views

Which Kinect to use for robotic arm pick and place application with object detection?

I am building a robotic arm for pick and place application. The robot is going to recognize several objects using the RGB feed from Kinect (will use a model such as YOLOv2 for object detection, ...
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0answers
61 views

Transforming position to torque

first question in this forum :D so i started creating a 2 link robotic arm in SIMULINK and made a function that builds its trajectory (cubic spline) and used it as an input for my joint. so my input ...
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0answers
151 views

My robot arm vibrates during operation. Why?

Introduction: I have modeled my 5-DOF robot arm in a simulation environment to test trajectories for my physical model. I have export the joint variables from the simulation as a .csv file. Then ...
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0answers
523 views

How do I choose the stepper motor torque for my robotic arm

I'm a communication engineer so my knowledge about robotics is very little. I know the basic formula of torque T=mgL in my project I have 2 arms & 2 motors i used a torque calculator online ...
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0answers
42 views

Correct Hardware for a Small Lightweight Robotic Arm

I'm building my first robotic arm and I am new to robotics generally, but I have tried to do some research. I need to build a robotic arm that will be relatively lightweight and will need to grab ...
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0answers
175 views

Scara vs. Articulated arm robot

My setup is such that my tools reside on a wall and table directly adjacent to my work bench. I wish to build an arm that will ultimately grab tools and give them to me without me having to move from ...
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0answers
37 views

F3 robot communications protocol?

I am considering writing a program to communicate with a Thermo Scientific F3 robot arm in order to eliminate their obsolete C500C controller. Does anyone know the communications protocol to/from the ...
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0answers
1k views

Get the arm joint angles with kinect 1

I am Carlos Barreiro and I am studying a Robotics Master. Now I am working with my Thesis. The project consists in the teleoperation of the a robot with Kinect (model 1). More specifically, I am ...
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0answers
652 views

Matlab Simulink showing following errror: kinematic constraints cannot be maintained

I'm using simulink to get joints torque by giving motion input. I create very simple CAD model in solidworks to learn simulink. Simulink model is showing in below figure. During update it shows no ...
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0answers
80 views

Inverse kinematics for a robot lamp

I've been working on a robot lamp. Looking something like this: So i had a few questions. I've decided to simplify the movements by giving the head a fixed orientation like you see in the picture. ...
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0answers
111 views

How to select the parameters of the Sliding Mode Control of a Robotic Arm?

I working on sliding mode control (SMC) of a 4 DoF manipulator, I don't know how to select the discontinuity gain matrix, $ K$ , the surface constant (the diagonal gain matrix $\Lambda$ components).
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0answers
261 views

Installing OpenNI on Pcduino

Following my previous question about pcduino+kinect, decided to go ahead and buy the pcduino I wish to run my robot with (kinect+pcduino+shields). However I'm having trouble getting started: I tried ...
0
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1answer
32 views

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 ...
0
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1answer
41 views

Dexterity calculation with dual quaternions

How can the manipulability of a robot arm be calculated when the kinematics are described with screw theory such as dual quaternions? These methods are sigularity-free, but what could we say about ...
0
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0answers
41 views

From an end-effector trajectory to joints movements

let's assume that our robot consists of 3 degree-of-freedoms. In order to move the end-effector of this robot along a straight line, these 3 joints have moved as below: Now, if the desired end-...
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0answers
31 views

Quaternionic feedback for for cartesian impedance control

I've seen that there are plenty of ways of generating orientation errors with quaternions. But the one I've seen most often is the following: For example, say that for a quaternion $Q = \{\eta, \...
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0answers
15 views

Rotate the end-effector around its Xf axis

I am working on a 7 DOF robot (7 rotational joints). I used euler angles to let the robot point down. Zf (Z of the last frame "end-effector frame") is the direction of the end-effector. What I want to ...
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0answers
12 views

DH Notation for Bend End Effector of RRR Articulated Arm

Hello, I want to ask about the DH notation for this RRR Robot with special end effector (See in the picture). I have a problem when writing the DH notation from join 3 to the end effector. the L shape ...
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0answers
33 views

What are the steps to calculate inverse kinematics of a robot arm with a flat hand?

The goal is to keep the hand as it extends from the wrist flat at all times, to hold a vertical tool. I've got some great resources that have helped me solved FK and am now struggling a bit with the ...
0
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0answers
23 views

I want to Calculate the Joint Velocities and Angular Accelerations of 5 DOF Youbot kuka robotic arm

I'm working on an assignment where I need to derive Velocity Kinematics for 5 DOF Youbot kuka robotic arm manipulator. I want to Calculate the Joint Velocities and Angular Accelerations of 5 DOF ...