## Velocity of 2-Joint Planar Robot Arm

In Robotics | No commentFor a simple 2-link planar robot we introduce and derive its Jacobian matrix, and also introduce the concept of spatial velocity.

14 Jul

For a simple 2-link planar robot we introduce and derive its Jacobian matrix, and also introduce the concept of spatial velocity.

14 Jul

We introduce the relationship between the velocity of the robot’s joints and the velocity of the end-effector in 3D space.

14 Jul

We will learn about the relationship, in 2D, between the velocity of the joints and the velocity of the end-effector — the velocity kinematics. This relationship is described by a Jacobian matrix which also provides information about how easily the end-effector can move in different Cartesian directions.

14 Jul

This video gives summary of inverse kinematics.

14 Jul

An alternative for smooth motion between poses is Cartesian interpolated motion which leads to straight line motion in 3D space.

14 Jul

To move a robot smoothly from one pose to another we need smooth and coordinated motion of all the joints. The simplest approach is called joint interpolated motion but it has some limitations.

14 Jul

For a redundant robot the inverse kinematics can be easily solved using a numerical approach.

14 Jul

For real robots there are a few extra things to think about. Is a particular point actually reachable? Our old friend, singularity or gimbal lock reappears in the wrist.

14 Jul

Let’s look at numerical approaches to inverse kinematics for a couple of different robots and learn some of the important considerations.

14 Jul

To simplify the inverse kinematics most robots have a spherical wrist, a particular mechanical wrist design. For robots where the inverse kinematics is too hard to figure out we can solve the problem numerically, treating it as an optimisation problem.

14 Jul

A characteristic of inverse kinematics is that there is often more than one solution, that is, more than one set of joint angles gives exactly the same end-effector pose.

14 Jul

For real robots such as those with 6 joints that move in 3D space the inverse kinematics is quite complex, but for many of these robots the solutions have been helpfully derived by others and published. Let’s explore the inverse kinematics of the classical Puma 560 robot.

14 Jul

A really important function when performing inverse kinematics is the inverse tangent or arctan function. We revise how this function works for angles in all quadrants of the circle and introduce a useful variant known as atan2.

14 Jul

We repeat the process of the last section but this time consider it as an algebraic problem.

14 Jul

We revisit the simple 2-link planar robot and determine the inverse kinematic function using simple geometry and trigonometry.

14 Jul

We will learn about inverse kinematics, that is, how to compute the robot’s joint angles given the desired pose of their end-effector and knowledge about the dimensions of its links. We will also learn about how to generate paths that lead to smooth coordinated motion of the end-effector.

14 Jul

This video gives summary of Robot Manipulator Arms.

14 Jul

This lecture has been about kinematics and we define that term.

14 Jul

The workspace of a robot arm is the set of all positions that it can reach. This depends on a number of factors including the dimensions of the arm.

14 Jul

The pose of the working part of a robot’s tool depends on additional transforms. Where is the end of the tool with respect to the end of the arm, and where is the base of the robot with respect to the world?