Questions tagged [dynamics]

Dynamics is a branch of applied mathematics (specifically classical mechanics) concerned with the study of forces and torques and their effect on motion, as opposed to kinematics, which studies the motion of objects without reference to its causes.

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what does free or forced torque mean in robot arm dynamics?

I'm trying to understand the dynamics (torque , velocity, etc ) of how a simple 2 DoF robotic arm rotates. I am using the RoboAnalyzer simulator 1 . It has a Inverse Dynamics setting of "Free&...
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Combining dynamic movement primitives to create new ones

this is my very first question and I want to thank everyone for the massive contribution to the community! On to my question now, here is a quick definition of my idea/problem: I have created a "...
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Body angle of a centre-articulated robot

Wondering if anyone can help me out with this one, or point me in the right direction. I am working on a centre-articulated robot, which is steered via a push-pull chain drive. The chain drive is ...
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Force sensors output when inclined

So here is the context: I am working on a motorcycle simulator. It consists of a motorcycle frame mounted on different actuators (see picture on the left). In particular, the two actuators at the ...
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Why in forward bending knee orientation in quadruped legged robot require less torque in knee joint?

I'm trying to find answer in terms of physics explanation, why knee joint torque requirement is less in the forward bending leg orientation of a quadruped legged robot. I'm referring this article, in ...
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3-links Robot Dynamic PD Computed Torque Control

I am designing the PD control of 3-links robot using Simulink. I can't figure out what to do in the 'Robot' block to get the acceleration d_qq back to calculate the error. What is happening in this '...
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How to solve this basic dynamics/inverse kinematics problem

Suppose I have a 6-DOF robot arm with revolute joints whose tooltip is at some position $\bf{r_0}$ and I want to move it through some trajectory ${\bf r}(t)$. For simplicity, assume there are just 2 ...
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Computation of centrifugal and Coriolis matrix

So I have a seesaw-cart electromechanical system which I want to control. It has 2-DOF (the angle of the seesaw $\varphi$ and the cart position $s$). I used the Euler-Lagrange method to get my ...
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Extract the potential energy from the gravity vector

I have a recursive Newton Euler algorithm from which I can compute the gravity vector. My question is, which is the better way to compute the potential energy? I know the following relation between ...
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Defining the specifications required by a 6DOF robot to impose a harmonic sinusoidal motion

Perhaps a bit of a simple question, but since I don't have a background in robotics/engineering, then I imagine this would be the perfect place to ask such a question. I am buying a 6-DOF Stewart ...
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Calculate time from 6DOF state space modeling of a quadcopter

I'm new here. I have the 6DOF state space representation of a quadcopter given below, \begin{align} \dot x(t) &= Ax(t) + Bu(t) \end{align} Where, $x(t)$ = State Vector, $u(t)$ = Input (or ...
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Equations of motion with mass attached to end effector and external force

I have to find the equations of motion for the given manipulator: The links of the manipulator are considered weightless and the equations of motion have to be derived by using the Lagrange equations....
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Park and Lynch $F = ma$ derivation for a single rigid body

I'm having some conceptual difficulties with a derivation presented in the Modern Robotics text by Park and Lynch. Here are the relevant parts: At the beginning of the book, they insist that ${\it ...
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Peter Corke Robotics Matlab Toolbox the problem of inverse dynamics in the Franka Emika Panda model

I have the following question about the Franka Emika Panda dynamic model. In case I perform the solution of the inverse dynamics problem using Robotics Toolbox (Peter Corke) I get different results ...
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Kinematic Bicycle Model theta units

I don't understand the $\theta$ units. The bicycle model defines $\theta$ as: $$\theta=\theta +\frac{v\cdot\tan\delta}{L}\cdot$$ Where $v$ is the vehicle velocity, $L$ is the wheelbase distance, and $\...
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Holonomic constraints on an upright wheel

A wheel moving in free space has the six degrees of freedom of a rigid body. If we constrain it to be upright on a plane and to roll without slipping, how many holonomic and nonholonomic constraints ...
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Implementing Dynamic Balancing on Robot Dog

I made a robot dog using Lewansoul LX-16a Smart Serial bus motors and a 3D printed body. I am using an Arduino Mega 2560 to control everything. I already have the inverse kinematics working. But for ...
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what is difference between twist and classcial velocity

In ch 8.2.1 Classical Formulation in the book Modern Robotics by Frank C. Park I know some remarks about this formula.The origin of coordinate system is coincidence with the mass center of the rigid ...
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perplexity about ch8.2.1 the linear dynamics, in the book <modern robotics>

From previous chapters, I think I have understand the twist, it is about the angular velocity and the linear velocity, the difference is that linear velocity is not one fixed point in the body but is ...
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How to obtain generalized force due to moment?

I understand how to obtain the generalized force due to linear force, but the following picture gives the formula 2.82 to obtain the generalized force due to moment, how to demonstrate it pictures ...
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Spherical Parallel Manipulator Lagrangian problem

I faced a very serious problem and I urgently need the help of specialists in robotics, mechanics, physics and mathematics. I am trying to derive equations of motion from the Lagrangian of a spherical ...
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Cartesian Stiffness Matrix and Complieance Matrix of Spherical Parallel Manipulator

In the article https://www.sciencedirect.com/science/article/abs/pii/S0094114X14000020, I came across the construction of a Cartesian stiffness matrix. On page 14 I see the components of the moments ...
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how to find the kinematic and dynamic model of the mechanism

enter image description here 5 links 4 revolute joints find the kinematic and dynamic model ,link 3 should be horizontal with ground and one end of link 1 and 5 there are sliders enter image ...
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Multidimensional obstacle avoidance in ODE. Part II

Multidimensional obstacle avoidance https://math.stackexchange.com/questions/4146255/multidimensional-obstacle-avoidance-in-ode For some time, I studied this question more closely and came to the ...
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Jacobian of Euler's rotation equations

I propagate the attitude of a satellite in a free-floating, torque free environment from $t_k$ to $t_{k+1}$ by integrating Euler's equation of motion: $$ \dot{\omega} = [J]^{-1}([\omega]_{\times}[J]\:\...
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Multidimensional obstacle avoidance

Artificial potential barriers are known that allow robots to avoid obstacles. They are constructed as follows. https://authors.library.caltech.edu/106548/1/2010.09819.pdf Can you please tell me how ...
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Looking for a course (online?) RE: systems with XY stages

Using XY stages is common in many fields: 3D printing Genetics instruments semiconductor lithography automated microscope slide imaging See for example https://www.asml.com/en/technology/lithography-...
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How to calculate center of mass with a prismatic joint

Suppose we a 1DoF planar robot with only 1 prismatic joint (for the sake of the example). The prismatic joint can extend the link or shrink the link. Suppose the length of link 1 is a, and suppose ...
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Range of a heading angle [0,2π) or [−π,π)

Consider the unicycle dynamics in 2D plane: $$\begin{array}{l} \dot x = v\cos \varphi \\ \dot y = v\sin \varphi \\ \dot \varphi = \omega \end{array}$$ What is the range of the heading angle $\phi$? ...
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Ground based path generation from RGBD camera

How does one generate a trajectory for a ground vehicle using an RGBD camera? For a drone it's simpler since you're not constrained by having to move on the ground but it's not clear to me how ...
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Velocity-Control of a manipulator without a dynamic model

I have a five DoF robot. Each axis is connected to a cylinder. You can send PWM values to each cylinder and you are able to read out the position values of each cylinder which makes it possible to ...
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Quadrotor dynamics: How is torque created

I'm a software engineer and I've recently engaged into Robotics field. I've started by a course on Coursera which talks about Aerial robotics and thus quad-rotors. I'm trying to understand how quad-...
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When is the Quadcopter out of the control?

Assuming ideal environment/hardware flying conditions, is it possible that the autopilot loses the control of the quadcopter? What is the maximum tilt in roll and pitch that is allowed for the ...
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Stationary/inertial reference frame

In Modern Robotics by Kevin Lynch, there is a term "stationary" frame, but this is never defined. Googling shows that this is synonymous with inertial frame. Apparently inertial frame means ...
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how to find Singularity and jacobian Inverseof 5 DOF Robotic arm?

I am working on calculating the Jacobian Determinant to find the singularity of my 5 DOF Robotic arm, I have calculated the jacobian matrix, and the matrix I got is a very large value As it is non ...
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What is the difference between The state-space equation and The configuration-space equation

The craig(p.180) states that equations can be made to represent the dynamic equations. The first one being the state space equation. $\tau=M(\Theta)\cdot\ddot{\Theta} + V(\Theta,\dot{\Theta}) + G(\...
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2 votes
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How to calculate potential enegy of manipulator dynamics?

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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133 views

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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3 votes
1 answer
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Motion profile and Motion control scheme, how do they interact?

I'm studying motion control and I start with the simplest case, I have to go from A to B in a straight line using a trapezoidal motion profile. I understand that in a real case, due to the fact that ...
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3 votes
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How to calculate Inertia tensor?

I'm trying to obtain dynamics of a 4 DOF robot. Firstly, I calculated all Transformation matrices and Jacobians. While solving Lagrangian there is a term I - Inertia tensor . I couldn't understand the ...
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How to properly model a non-holonomic system?

I'm trying to model a robot which is composed of a non-holonomic and a holonomic system overall is non-holonomic. Basically it's a robot arm + mobile platform. So far I have found a similar work like ...
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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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Moment of Inertia of a Dumbbell

hope you are all doing well. I am taking a course at Coursera about Robotics and in one of the quizes, I had some problem with a particular question. I passed the quiz (4/5 correct answers), however I ...
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How to find inertia parameter of payload automatically

I know of several robot manufacturers who can perform automatic inertial measurement for 6 axis robots. Fanuc, for example, moves with axes 5 and 6 each from +180 to -180 °, once with and once without ...
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Cartesian Impedance control Damping Design (Double Diagonalization)

In the literature, it is often seen that for a system: \begin{align} \Lambda \ddot{e} + D_d \dot{e} + K_d e = F_{ext} \end{align} A dynamic damping matrix is required for a robot to take ...
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How to solve dynamics of cardan joint manipulator

We can use the Recursive Newton-Euler Algorithm to solve the dynamic problems of open chains manipulator, but how about the Cardan-joint manipulator? For example, if we have one Cardan joint (...
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Why applied joint torque will affect another joint?

I want to ask a very simple question. For the robot dynamics Newton-Euler algorithm, suppose there is a two-link planar robot, we can write the simple dynamic equation form as $M(\theta)\ddot{\theta} ...
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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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Understanding Impedance Control

I have a question regarding impedance control for a robotic manipulator. Given that we have a task space trajectory: $\ddot{x}$, $\dot{x}$ and $x$ And the dynamics model of the robot: $$\tau = M(q)\...
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Can workspace of a manipulator change after considering its dynamics?

As per my knowledge, the workspace of a manipulator can be determined if one knows the forward and inverse kinematics. But is it possible that the workspace of the manipulator can change after ...
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