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A robotic arm is a type of mechanical arm, usually programmable, with similar functions to a human arm; the arm may be the sum total of the mechanism or may be part of a more complex robot.

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How to calculate screw axes relative to end effector [on hold]

Background: I was reading this book called 'Modern Robotics: Mechanics Planning and Control' -by Kevin M. Lynch and Frank C. Park In the section 4.1.2 'Screw Axes in the End-Effector Frame' they talk ...
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21 views

Controlling industrial grade dc motors fitted with analogue or digital encoders for robotic arm

I am new to such industrial motors. I searched through the datasheets of these motors ( analogue and digital ) and didn't get clear answer about how I would be able control with MCU like Arduino or ...
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0answers
23 views

Best desktop robot to buy with the best support [closed]

I want to get a desktop robotic arm to learn path planning for robots and I was wondering what the best brand to buy was. Background I was hoping for a version that has a lot of community support so ...
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2answers
53 views

Controlling Stepper or DC motor with L298 or L293 and getting operation similar to Servo for 6 dof arm

I will be using 1:4 gear ratio and thus will require a motor with a continuous 360 motion and a high torque for efficient functioning. Servo motors with continuous rotation and high torque are very ...
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4answers
172 views

Denavit-Hartenberg convention in practice

How are the coordinate frames and D-H parameters determined in industry? Does one use the CAD drawing of the arm or physically take measurements of the actual arm?
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1answer
24 views

Finding Joint speeds for each joint of a 6DOF arm (UR10) using the Inverse Jacobian

Background: I have access to a UR-10, 6DOF robotic arm through my school (I'm very new to robotics). I know the desired set of linear speeds that I want in the x,y, z-direction in terms of the end ...
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2answers
42 views

How to move a Stepper Motor to a desired angle with raspberry pi?

I will be using stepper motor in 6 DOF robotic arm along with Servo motors. Unlike Servo motor ,I find difficult to control Stepper motor. I was earlier using only Servo Motors but due to lack of ...
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2answers
50 views

Are there standard angular velocities when it comes to robotic arms?

for manipulators that lift heavy loads, e.g. a car or a cow, what would be the ideal angular velocity? Are there any standards for arm safe moving speed? (of course I know it depends on the project ...
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1answer
25 views

Creating linear end effector motion using joint speeds: Converting tool speed to joint speeds

Background Information: I'm new to robotics and my school currently has access to a 6DOF Universal Robot (UR-10). I'm programming it using its scripting language URscript and the arm has these two ...
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1answer
31 views

Control Pneumatic Cylinder Position with Potentiometer and Analog Comparator on Arduino Uno

I am building a robot arm that is actuated by a pneumatic cylinder. Extending and retracting the piston would increase and decrease the joint angle respectively. This is done using a 5/3 solenoid ...
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0answers
16 views

How to calculate the forces acting on an object of mass 'm', which is vacuum gripped at the end of a robot arm? [closed]

I would like to understand, how to calculate the forces/what all forces act on an object that is currently being gripped by a suction gripper and when it moves. Gravity is one, which will cause the ...
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24 views

Best way to actuate J5 (wrist) on 6 axis robot arm?

I'm designing a robot arm with an intended payload of ~2 kg and 60 cm reach. I've been working off of the AR2 arm design, which has the typical turret | shoulder | elbow | wrist roll | wrist ...
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1answer
20 views

Transformation matrix using DH parameters

I want to write a Matlab function which takes the DH parameters as input and outputs a 4X4 transformation matrix. The code I have written is : ...
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1answer
31 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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0answers
39 views

I am confused about this jacobian concept Would be great if some one solves this question?

For a two link planar manipulator length of the first link is 2 units and length of second link is 1 unit.It's Jacobian matrices at 3 different configuration(named J1,J2 and J3) have been given as ...
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2answers
52 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
4 views

How can I measure the BEMF signal and zero cross detection?

I have started to work on a Sensorless BLDC motor. In open loop mode, Sensorless BLDC motor is running in properly. My question is how can I measure the BEMF signal and zero cross detection? Motor ...
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1answer
54 views

OnRobot RG2 Gripper on UR3 with TCP communication

I am using a UR3 Robot with OnRobot RG2 Gripper. I have successfully connected the robot to my computer via Ethernet and i am able to send move commands and receive data successfully with Python. But ...
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0answers
24 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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1answer
27 views

Two 4 bar mechanism vs stepper motor on each linkage in a 4 DOF robotic arm

I am planning to make a 4 Degree of Freedom(DOF) robotic arm. I have a confusion in mechanical design of the robot. Shall I use two 4 bar mechanisms to reduce the number of actuators? or a stepper ...
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1answer
36 views

How to transfer motion between these two parts?

I'm trying to model this arm and I'm having a problem knowing what way could I use to make the red part always parallel to the surface of the table
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1answer
45 views

Using python to create AI

Just asking a quick question about implementing some python AI. I have a home built circuit running an ATmega32u2 chip and I was wondering if it’s possible to use this code on the chip? Or do I have ...
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0answers
12 views

Simulation of error in following trajectory for robot manipulator

I am working on a surgical manipulator project where I have optimized the link lengths of the manipulator for maximum isotropy. Does the maximum isotropy reduces the error in following predefined ...
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0answers
46 views

How to find jacobian using kdl that matches with bullet physics jacobian

I am trying to calculate jacobian with kdl (pykdl) and bullet physics (pybullet). With bullet physics I can only find Jacobian of whole robot, but I want to find Jacobian for a kinematic chain. So I ...
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1answer
61 views

How to plan path for robotic arm with RRT?

I have written simple RRT planner however I am not sure how to apply it to a robotic arm path planning. The issue is that of analytical solution absence to inverse kinematics problem. Let me explain. ...
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26 views

Straight Line, Point to Point Movement

I am currently programming a robot using G-Code to draw basic shapes with a pen. When simulating my code for a square, the robot moves from a corner in a diagonal line, until returning straight. At ...
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1answer
120 views

Solving Inverse Kinematics for ABB IRB 120

I am working on an ABB IRB120 simulation using MATLAB Simulink. I use the decoupling method to solve the inverse kinematic of the robot. However, I have some questions related to the computation of ...
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0answers
30 views

Screw based Jacobian

I am working on kinematics of 5-DOF robot. I already derived geometric Jacobian for position and orientation control. But for singularity analysis, I require a simplified jacobian. And that can be ...
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1answer
33 views

Angular velocity vector expression uncertain?

I have this problem of an excavator from a test I took a while ago. Frame $\underline{\vec{e}}^0$ is the origin. Frame $\underline{\vec{e}}^1$ rotates around $\underline{\vec{e}}_{3}^0$ with angle $\...
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28 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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2answers
62 views

Plotting SE(3) points in a 3D graph

I have a data-set containing points in SE(3), i.e the 4 $\times$ 4 transformation matrices and the corresponding dual quaternions. Now, I want to plot these points in a 3D graph. How to generate this ...
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0answers
12 views

Some Question about TOSHIBA robot

TS Series robot what is the "Point Position" what is the "posture" I want to know what the meaning of each location information means. 6-axis (x,y,z,a,b,c,u,v) SCARA (x,y,z,c,t) what is the "...
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60 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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0answers
42 views

Creating transfer FNC

im working on controlling a 2 link arm with simulink, and wanted to try torque control. I've built a trajectory generation function in matlab and it gives me the position that the joint needs to be in ...
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1answer
105 views

Singular configurations of a 7-dof robotic arm

I want to check for singular configurations of a 7-dof robotic arm (RRRRRRR). I have found the geometric Jacobian and it is a 6x7 matrix. If my theoretical background is solid when the Jacobian loses ...
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0answers
14 views

Choosing motor for shake/push pull action?

I'm looking forward to choose motor for shake or fast push/pull action. On this video you can see example motion on 3:04. I read linear motor does that but looks like much slower. What kind of motor ...
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0answers
50 views

Basics of robotics mathematics, transformation

Calculate transformation which let us to take a item from a table if we know: position of robot base($R$), table($S$) with mounted TV camera($K^{S}$) which send a item's image $D^{K}$. A grip system $...
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40 views

Planar manipulator matlab simulink error

I want implement feedback linearization for a planar manipulator 3 DOF. I define the desired position,velocity and acceleration for each joints for every 0.01s. So I set in solver options "Fixed-step ...
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0answers
29 views

Automatic control of 2 motors robotic arm by 2d location

I'm new to robotics I have a robotic arm consisted of 2 DC worm gear motors that moves in the 2D plane I want the arm to move toward certain object, and I have the (x,y) location of that object. ...
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1answer
246 views

How to move robotic arm in straight line

So here is my problem. I need to grab an object with my robotic arm, but I don't know the position of the object. The only thing I know is the angle between object and gripper. You will maybe better ...
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1answer
203 views

inverse kinematics matlab RVC for 3 joint RRR

Hi im having problem with Inverse kinematic using RVC toolbox in matlab for RRR manipulator. ...
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0answers
169 views

Robot arm energy and stability optimization

For a project I need to come up with two constraint optimization problems in robotics. The task of the robot is to move the end-effector in a straight line (e.g. in the x direction) in Cartesian ...
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0answers
33 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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3answers
156 views

Zero-Point/Home Position/Origin of Absolute Encoder: What is the Proper Name?

I'm writing an academic paper describing the calibration of a system. Part of that system is an absolute rotary encoder measuring the angle of a joint. However, the position at which the encoder gives ...
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1answer
90 views

How can a coaxial stepper motor be used to drive the Z axis effector of a SCARA robot?

I am new to robotics and mechanical engineering. I am trying to understand how the Z-axis (and effector) of a SCARA robot can be driven by a stepper motor with it's shaft coaxially aligned along the ...
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1answer
59 views

Is Robust Control and robotics well applied together?

There are many control methods who sounds great and have nice math etc. But many of them are not realistic in real life. In robotics, Adaptive Control is well applied because Adaptive Control make ...
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2answers
76 views

Calculating C for a 6-DOF robotic arm

I've seen this equation for calculating the dynamics of a robotic arm a bunch: $\boldsymbol{\tau} = \boldsymbol{M}(\boldsymbol{q})\ddot{\boldsymbol{q}} + \boldsymbol{C}(\boldsymbol{q},\dot{\...
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1answer
47 views

Confusion about Jacobians stemming from class notes

So I thought I understood well enough what a Jacobian was (in the context of an $n$-DOF robot) -- a function that takes a vector of n joint positions and returns an $n \times n$ matrix that can be ...
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1answer
32 views

How can i convert Torque input into PWM signal?

I am working on a project in which i have a robot working with stepper motors. I wish to control this robot with simulink. How can i convert the input( Analog sin input ) into the PWM that can be used ...