# Questions tagged [inverse-kinematics]

Inverse kinematics is a subtopic of kinematics dealing with equations that describe the joint parameters necessary to move a robotic arm to a particular position. Also called motion planning.

191 questions
Filter by
Sorted by
Tagged with
3answers
10k views

### How can the inverse kinematics problem be solved?

The forward kinematics of a robot arm can be solved easily. We can represent each joint using Denavit–Hartenberg transformation matrices. For example, if the $i^{th}$ joint is a linear actuator, it ...
3answers
21k views

### Computing the Jacobian matrix for Inverse Kinematics

When computing the Jacobian matrix for solving an Inverse Kinematic analytically, I read from many places that I could use this formula to create each of the columns of a joint in the Jacobian matrix: ...
3answers
2k views

### With a 6-axis robot, given end-effector position and range of orientations, how to find optimal joint values

Given a six-axis articulated robot arm holding a tool at its end-effector, if I have a desired tool position and tool orientation, there will be exactly 1 solution to the inverse kinematics equation ...
2answers
201 views

### Singularity problem at Inverse kinematic solver

I am struggling with this problem for days. I really hope that someone could give me a hint what the problem is. The robot consists of 5 axes. The first axis rotates around the z-axis and other 4 ...
2answers
3k views

### Is there an analytical solution for inverse kinematics of a 6 DOF serial chain?

Let's take a 6 DOF robotic structure. It's consisting of the 3 DOF global structure for the position - and the 3 DOF local structure for the orientation of the endeffector. If the last 3 axis (of the ...
2answers
1k views

### Are inverse kinematics and reinforcement learning competitive techniques?

Are inverse kinematics and reinforcement learning techniques contending techniques to solve the same problem viz. movement of robotic manipulators or arm? By a glance through the wikipedia article, ...
2answers
2k views

### Solving Inverse Kinematics with Gradient Descent

I am trying to implement my own inverse kinematics solver for a robot arm. My solution is a standard iterative one, where at each step, I compute the Jacobian and the pseudo-inverse Jacobian, then ...
1answer
451 views

### Is the geometric inverse problem's solution “continuous” for a redundant robot?

Let's say my redundant robot is at an operationnal position $x$. Is the set of all possible joint configuration "continuous", which would mean that it is possible to explore all the possible ...
2answers
276 views

### Is there a tool for building and analysing robots (kinematics, control) visually?

I am reading research papers about robotics and many of them follow the same pattern: some construction is established kinematical formulas are read from the mechanical structure the state space is ...
2answers
507 views

### Decision trees for solving 2D inverse kinematics?

While experimenting with the OpenCV Machine Learning Library, I tried to make an example to learn the inverse kinematics of a 2D, 2 link arm using decision trees. The forward kinematics code looks ...
1answer
8k views

### Computing inverse kinematic with jacobian matrices for 6 dof manipulator

I'm trying to calculate the inverse kinematic for an 6 dof manipulator. Task: A target point $p_{target} = (x,y,z)^T$ and the orientation $o_{target} = (a, b, c)^T$ are given and I want to get the ...
1answer
3k views

### Can a Jacobian be used to determine required joint angles for end effector velocity/position?

I'm in the early stages of working with a simple robot arm, and learning about the Jacobian and inverse kinematics. From my understanding, the Jacobian can be used to determine the linear and angular ...
2answers
2k views

### Inverse kinematics with joint contraints

I have a manipulator having 4 revolute joints with some movement limitations. So, when I apply inverse kinematics, I'm getting results which are out of limits. Please provide me an algorithm that ...
2answers
1k views

### Assigning Frames and Deriving Link Parameters

The textbook I'm using doesn't have the answers to the practice questions, so I'm not sure how I'm doing. Are the following DH parameters correct given the frames I assigned? The original question is ...
3answers
995 views

### How to apply Inverse Kinematics with angle constrained servos?

I want to implement Inverse Kinematics and i understand the inverse jacobian method but the servos i have only have a range from -90 to +90 degrees, how can i implement this detail in the algorithm? I ...
4answers
951 views

### Forward and Revers Kinematics For Modified Hanging Plotter

I'm building a modified version of the standard hanging plotter (v-plotter). The basic idea is that you have two cables hanging from stepper motors which form a triangle supporting the pen at the tip. ...
2answers
1k views

### Forward kinematic and inverse kinematic… When to use what?

I am not quite sure if I quite understand the difference between these two concepts, and why there is a difference between these two concept. Yesterday I was trying to compute the jacobian needed ...
3answers
409 views

1answer
155 views

### Do DH parameters change for a scaled robot 3d model?

I have the actual DH parameters of a robot: d1 = 0.4865 m d2 = 0.600 m d3 = 0.065 m a1 = 0.150 m a2 = 0.475 m all other di's and ai's are zero. Can I use these ...
2answers
234 views

### Inverse kinematics after calibration

I am working on a 6DOF robot arm project and I have one big question. When I first derived the inverse kinematics (IK) algorithm after decoupling (spherical wrist), I could easily get the equations ...