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7 votes
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Is there a way to determine which degrees of freedom are lost in a robot at a singularity position by looking at the jacobian?

Not by merely looking at Jacobian but by looking at the Singular Value Decomposition of the Jacobian, one can see the degrees of freedom that are lost, if lost. Of course it technically somehow turns ...
Suneesh Jacob's user avatar
6 votes

Is there any robot stability control equation that describes the relation between velocity of the robot and its orientation?

That's not obvious. If I'm in a tank, going 0.5 km/h, I don't need to slow down at all. If I'm in a bobsled going 100km/h and the track banks, I don't need to slow down at all. When you steer, you ...
Chuck's user avatar
  • 16k
6 votes
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Extended Kalman Filter in robotics - Worth it?

The Kalman filter is an optimal linear filter in the presence of Gaussian noise. It is optimal in the sense that it minimizes the mean-squared error. This means that the covariance of the estimated ...
Parker Lusk's user avatar
4 votes
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Definition of payload for industrial robots

If you only consider the simple physics of the problem you are completely right, it should be able to move lower payloads at lower velocities and accelerations. However, the maximum payload can only ...
50k4's user avatar
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4 votes
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Do you have to stop a programmable logic controller to update its logic?

The function you are looking is called online change (e.g. Beckhoff Online Change), at least by some PLC Manufacturers. If you change a few blocks (in case of FBD) or a few contacts (in case of LAD) ...
50k4's user avatar
  • 6,682
4 votes

What is the difference between a CNC router versus a CNC mill?

Not a big fan of using head motions or type of spindle to define the difference, as there are lots of exceptions to each. Many 5-axis mills move the head in various ways beyond just Z. Datron makes ...
Bob Warfield's user avatar
4 votes
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How are huge industrial robots powered?

Industrial Robots with having as aim manipulation of large objects are powered electrically in almost all cases (30-40 years ago there have been popular hydraulic variants). Industrial robots are ...
50k4's user avatar
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3 votes
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Implementing an analytic version of an inverse kinematic

Given a desired pose: $$T^{desired} = \begin{bmatrix} s_x&n_x&a_x&P_x\\ s_y&n_y&a_y&P_y\\ s_z&n_z&a_z&P_z\\ 0&...
ghanimmukhtar's user avatar
3 votes

Implementing an analytic version of an inverse kinematic

Your Jacobian-based approach is great for velocity control, or when the manipulator is close to the original point. But remember, the Jacobian only gives a first-order approximation to the ...
SteveO's user avatar
  • 4,396
3 votes

How are industrial robotics components purchased?

For an industrial setting funds are not unlimited but the value of the machine to the process is known or predicted and if the benefit is greater than the cost, the funds are sought. Relationships ...
hauptmech's user avatar
  • 4,445
3 votes
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Industrial Controllers - Why not adaptive control and robust control

In short, adaptive control and robust control (Hinf) are the difficult combination of computationally expensive and complicated to understand. Even if you do an excellent job of implementing one of ...
ryan0270's user avatar
  • 2,814
3 votes

Industrial Controllers - Why not adaptive control and robust control

If I had to guess, I would say that, in an industrial setting, you have a relatively high degree of certainty about the process you're controlling, and/or there isn't much emphasis on transient ...
Chuck's user avatar
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3 votes
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How do I model a simple robot arm as a plant?

Each joint of your robot is one motor. They are coupled though kinematic relations and dynamic physics. One straight forward way is to derive these so called 'equations of motion' using the euler-...
madn's user avatar
  • 189
3 votes
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Creating linear end effector motion using joint speeds: Converting tool speed to joint speeds

Joint velocities and tool velocities are directly related through the following equation $$ \dot{x} = J(q)\dot{q}, $$ where $\dot{x} \in \mathbf{R}^6$ is the tool (linear and angular) velocities, $\...
Petch Puttichai's user avatar
3 votes
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Gravity compensation

In an ideal scenario, yes, that should be the case. When gravity compensation is implemented on robots, all joints apply a torque to balance out the torque applied by the force of gravity. They should ...
Akshay Kumar's user avatar
3 votes

Gravity compensation

I'm afraid not, actually. Even if you have a perfect friction compensation and a perfect gravity compensation, you still need to deal with inertia. It will be extremely hard to swing it in arbitrary ...
Jongwoo Lee's user avatar
3 votes
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Position vs Image based visual servoing?

The problem in both cases is to move the robot tool to some pose relative to an object. Let's assume the camera is attached to the end of a robot arm (eye in hand case) so we will consider this a ...
Peter Corke's user avatar
  • 1,702
3 votes

What should be the ideal ratio for link lengths ( L1/ L2) of a 2 link manipuator robot with revolute joints?

This is a good question, and one you should definitely consider when designing a new robot arm. But unfortunately, it depends a lot on the configuration of your arm (i.e. how the joints will be bent),...
Ben's user avatar
  • 5,865
3 votes

What is the meaning of joint space and configuration space and task space?

All "spaces" are used to define the current state of the robot, but with differences. The state of the robot is a point (also known as a configuration or pose) in a space. Please note that ...
50k4's user avatar
  • 6,682
3 votes
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Articulated Body Algorithm with gear ratio

In Featherstone's book "Rigid Body Dynamics Algorithms", there is a section of Chapter 9 (specifically, 9.6) dedicated to explaining how to incorporate gears into a given dynamic model. At a ...
Brandon J. DeHart's user avatar
2 votes

How to implement PID control for robotic arm?

There are at least two different ways to get it: Explanation 1) For a very special class of mechanical systems like the robotics manipulator, the control law $u=-K_pe+g(q)$ with $K_p$ symmetric ...
cyberdyne's user avatar
  • 166
2 votes
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Need a pushing mechanism

You could use a rack and pinion as a linear actuator. A simple way of knowing when to stop turning the motor could be a contract sensor/button at the upper and lower position. You could also add ...
fibonatic's user avatar
  • 941
2 votes

Sensors in Collaborative Robots

This question seems to be about robots collaborating with people -- not with each other. In general, it might be unsafe for a person to stand near a machine that's capable of exerting harmful levels ...
Ian's user avatar
  • 11k
2 votes

KUKA robot - update coordinates

If you are working with windows then for KUKA programs you can use the (OrangeEdit), check it in this website, OrangeEdit Beta. It is free and it enables you to view and edit all the ...
ghanimmukhtar's user avatar
2 votes

Kuka KR16L-2 robot simulation base and wrist rotation inconsistent with original robot

Kuka robots have the axis positive and negative side clearly marked on them. Use these to define the orientations of the Z-axes assigned to the joints. With other words, try to reverse engineer the DH ...
50k4's user avatar
  • 6,682
2 votes
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How to dimension a 3 DOF robot arm with RRR configuration?

First of all you need to understand how the lenghts and masses effect the torque load on your motors. The masses and lenghts will give you a required torque, while your motors give you the available ...
50k4's user avatar
  • 6,682
2 votes

How to update the cartesian target when the robotic arm has a communication delay?

You should update the robot references (and current position) independently if there is an update from the mouse or not. If there is an update (i.e. after 100 ms) you should update the value sent each ...
50k4's user avatar
  • 6,682
2 votes
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Solving Inverse Kinematics for ABB IRB 120

To choose the best posture: If you have absolute encoders: compare which is the closest compared to your current position if you use incremental encoders: You need a reference at the beginning (e.g. ...
stoeppsel's user avatar
2 votes
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Finding Joint speeds for each joint of a 6DOF arm (UR10) using the Inverse Jacobian

If you are only interested in linear motion, instead of simplifying the Jacobian to a 3x3 matrix, you can express this contraint in the velocity componentet and have $\dot{X} = \begin{bmatrix} \dot{...
50k4's user avatar
  • 6,682
2 votes
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What robotic skills can I develop when working as a robot operator?

Considering your apparent education background, I’m surprised at this question... But regardless. Working with robots, when compared to making robots are very different things. This is not so much ...
DrMrstheMonarch's user avatar

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