# Tag Info

Accepted

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

First of all, singularities are not configurations that have the same end-effector position and orientation. Those configurations are inverse kinematic (IK) solutions to that end-effector pose (...
• 1,859

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

Singular configurations are configurations at which the Jacobian is rank-deficient. In this case $J$ is a square matrix, you can find conditions for singularity by solving $\det(J) = 0$. The last row ...
• 1,859
Accepted

### Matrix is singular error in GraphSLAM

Due to singularity in matrix (i.e. the condition of matrix during which determinant of matrix becomes zero), matrix cannot be inverted. So you can possibly try pseudo-inverse. It gives most ...

### Singular configurations of a 7-dof robotic arm

Think of those "terrible to look at" terms as diamonds in the rough. Yes, they look complicated at first. But you will find an amazing number of them will combine using basic trigonometric ...
• 4,396

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

I think you need to step back a bit and think beyond the math. An (E)KF is used to estimate the true value of a signal in the presence of noise; it's only because of this noise that we even need the ...
• 2,814
Accepted

### Null space of the Jacobian matrix for a robotic arm

Quite easily, by applying the definition of the Null Space straight away, you have to solve for: $$\mathbf{J} \left( q_1,q_2=0\right) \cdot \left[\dot{q_1}, \dot{q_2} \right]^T = 0.$$ You'll come up ...
• 4,005
1 vote

### How to resolve singularity in six arm robot

My suggestion is to add constraints to the motion planner (see here how to set them in MoveIt -please be sure to read the tutorial related to your ROS/ROS2 distribution!-), rather than editing the ...
• 152
1 vote

### Singularity problem at Inverse kinematic solver

As others have already pointed out, there must be an issue with your implementation of the IK algorithm since there shall not be any singular behavior in the descriptions you gave. Now you have two ...
• 4,005
1 vote
Accepted

### Reachable Position with endeffector robotic arm

One possible way to use the inverse kinematics equations. For obtaining the inverse kinematics equations you can either use the Jacobian matrix or the geometric approach. For a robotic arm that has ...
• 244
1 vote

### How to avoid matrix singularity in GraphSLAM

If $\Omega$ is singular, you cannot avoid a matrix singularity. This is like saying you want to solve the system of equations $$x = 1$$ $$x = 7$$ There are many techniques to avoid robotic ...
• 4,396
1 vote

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

Look into this robot (fragment from here under Apache license). It is in kinematic singularity position, because the axis of the two rotary joints below and above the middle joint C are parallel: ...
1 vote
Accepted

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

If $J$ is not square, solve $$|J^TJ| = 0$$ for $\theta_i$.
• 4,396
1 vote
Accepted

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

According to Pai and Leu, 1989, for a generic manipulator (which includes all 6R robots with a spherical wrist), the set of singular points of rank r are smooth manifolds in joint space of codimension ...
• 4,396

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