Actuators
In Robotics | No commentActuators are the components that actually move the robot’s joint. So let’s look at a few different actuation technologies that are used in robots.
14 Jul
Robotics
14 Jul
Robot Joint Control Architecture
In Robotics | No commentA robot joint is a mechatronic system comprising motors, sensors, electronics and embedded computing that implements a feedback control system.
14 Jul
Introduction to Robot Joint Control
In Robotics | No commentWe will learn about how we make the the robot joints move to the angles or positions that are required in order to achieve the desired end-effector motion. This is the job of the robot’s joint controller and in this lecture we will learn how this works. This journey will take us in to the realms of control theory.
14 Jul
Summary of Velocity Kinematics in 3D
In Robotics | No commentThis video gives summary of Velocity kinematics in 3D.
14 Jul
Jacobian and Number of Robot Joints
In Robotics | No commentA robot manipulator may have any number of joints. We look at how the shape of the Jacobian matrix changes depending on the number of joints of the robot.
14 Jul
The Analytic Jacobian
In Robotics | No commentNow we introduce a variant of the Jacobian matrix that can relate our angular velocity vector back to our rates of change of the roll, pitch and yaw angles.
14 Jul
Mapping 3D Spatial Velocity Between Coordinate Frames
In Robotics | No commentWe previously learnt how to derive a Jacobian which relates the velocity of a point, defined relative to one coordinate frame, to the velocity relative to a different coordinate frame. Now we extend that to the 3D case.
14 Jul
Velocity Ellipsoid in 3D and Manipulability
In Robotics | No commentThe Jacobian matrix provides powerful diagnostics about how well the robot’s configuration is suited to the task. Wrist singularities can be easily detected and the concept of a velocity ellipse is extended to a 3-dimensional velocity ellipsoid.
14 Jul
Inverting the Jacobian Matrix
In Robotics | No commentAs we did for the simple planar robots we can invert the Jacobian and perform resolved-rate motion control.
14 Jul
Velocity of 6-Joint Robot Arm – Rotation
In Robotics | No commentWe resume our analysis of the 6-link robot Jacobian and focus on the rotational velocity part.
14 Jul
Skew Symmetric Matrices
In Robotics | No commentWe have a quick revision of the skew-symmetric matrix. If you’re comfortable with this topic then go straight on to the next section.
14 Jul
Velocity of 6-Joint Robot Arm – Translation
In Robotics | No commentFor a real 6-link robot our previous approach to computing the Jacobian becomes unwieldy so we will instead compute a numerical approximation to the forward kinematic function.
14 Jul
Motion in 3D
In Robotics | No commentA body moving in 3D space has a translational velocity and a rotational velocity. The combination is called spatial velocity and is described by a 6-element vector.
14 Jul
Introduction to Velocity Kinematics in 3D
In Robotics | No commentWe will learn about the relationship, in 3D, 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. To do this in 3D we need to learn about rate of change of orientation and the concept of angular velocity.
14 Jul
Summary of Velocity Kinematics in 2D
In Robotics | No commentThis video gives summary of velocity Kinematics in 2D
14 Jul
Mapping 2D Spatial Velocity Between Coordinate Frames
In Robotics | No commentWe can also derive a Jacobian which relates the velocity of a point, defined relative to one coordinate frame, to the velocity relative to a different coordinate frame.
14 Jul
Velocity of 3-Joint Planar Robot Arm
In Robotics | No commentWe extend what we have learnt to a 3-link planar robot where we can also consider the rotational velocity of the end-effector.
14 Jul
Resolved Rate Motion Control in 2D
In Robotics | No commentWe will introduce resolved-rate motion control which is a classical Jacobian-based scheme for moving the end-effector at a specified velocity without having to compute inverse kinematics.
14 Jul
Velocity Ellipse in 2D
In Robotics | No commentThe end-effector is not able to move equally fast in all directions, and that in fact depends on the pose of the robot. We will introduce the velocity ellipse to illustrate this.
14 Jul
Inverting the Jacobian Matrix
In Robotics | No commentBy inverting the Jacobian matrix we can find the joint velocities required to achieve a particular end-effector velocity, so long as the Jacobian is not singular.