# Questions tagged [singularity]

To be used with questions regarding non-invertible matrices.

10 questions
1answer
30 views

### Why does singularity condition for a serial manipulator never involve the first joint variable

In planar 2R the singularity condition involves the second joint variable. In spatial 3R, singularities involve second and third link lengths and angles. Why does the first joint parameter never ...
1answer
70 views

### How to avoid matrix singularity in GraphSLAM

I am trying to implement GraphSLAM from Sebastian Thrun's paper, The GraphSLAM Algorithm with Applications to Large-Scale Mapping of Urban Structures. When I compute the inverse of my information ...
2answers
166 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
268 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 ...
1answer
24 views

### EKF singularity problem when measurement noise R is zero

my Extended kalman filter (EKF) program works well, my estimated state vector is same as real state vector when I give any positive definite number to measurement noise R. But I want to make ...
1answer
81 views

### Reachable Position with endeffector robotic arm

I have a 7 DOF robotic Arm. All the 7 Joints are rotational and have upper and lower joint angle limits. Now assume my end effector has a certain Pose $x = [X, Y, Z, a, b, c]$. My Question now is ...
2answers
73 views

### Matrix is singular error in GraphSLAM

I have gone through The GraphSLAM Algorithm with Applications to Large-Scale Mapping of Urban Structures. I implemented the code for GraphSLAM. The fundamental formula of GraphSLAM is \mu = \Omega^...
1answer
77 views

### Why are joint velocities very high near a singularity?

I am reading about singularities and I know that those are configurations which result in the same end-effector position and orientation. I also read that joint velocities get very high near that ...
2answers
915 views

### Calculating the singular configuration of a 3 revolute joint manipulator

I would really appreciate it if somebody could help me calculate the singular configuration of this simple manipulator I am confused since J is a 2x3 matrix and I cannot simply calculate the ...
1answer
86 views

### How big is the set of kinematics singularities?

Suppose we have an $n$-DOF robot manipulator and let $q \in \mathbf{R}^n$ denotes a robot joint configuration. Then a singular configuration $q'$ is a configuration at which the Jacobian $J(q')$ does ...