What is planar manipulator?
Planar manipulator: A manipulator is called a planar manipulator if all the moving links move in planes parallel to one another. Spatial manipulator: A manipulator is called a spatial manipulator if at least one of the links of the mechanism possesses a general spatial motion.
What are underactuated robotics?
An underactuated robot is a robot with fewer actuators (control inputs) than the number of variables describing its configuration (degrees of freedom). Some robots have this property unavoidably, while others are specifically designed this way, perhaps to save the cost of actuators.
What is a wrench in robotics?
It measures forces and torques in the frame {f}. We can package the moment and the force together in a single 6-vector called the wrench, just as we packaged the angular and linear velocity of a rigid body into a twist. Since we know the transform T_sb, we should be able to represent this same wrench in the {s} frame.
What is a twist in robotics?
In summary, a twist is a 6-vector consisting of a 3-vector expressing the angular velocity and a 3-vector expressing the linear velocity. Both of these are written in coordinates of the same frame, and the linear velocity refers to the linear velocity of a point at the origin of that frame.
What is mechanical manipulator?
In industrial ergonomics a manipulator is a lift-assist device used to help workers lift, maneuver and place articles in process that are too heavy, too hot, too large or otherwise too difficult for a single worker to manually handle.
What is serial and parallel manipulator?
Parallel manipulator vs. The basic differences between parallel manipulator (PM)and serial manipulators(SM) are structure and load carrying capacity, Serial manipulator carry less load compared to parallel manipulator due to cantilevered structure.
What is Underactuated manipulator?
Underactuated robot manipulator possesses fewer actuators than degrees of freedom (DOF). Complex internal dynamics, nonholonomic behavior, and lack of feedback linearizability are often exhibited in such systems, making that class of robots a challenging one for synthesis of control schemes.
What does over actuation mean?
There are many answers to this question: i) over-actuated system is system in which a number of inputs is more than its output state ii) When a system is equipped with more effectors than axes to control, the system may be over-actuated or redundant.
What is reciprocal screw?
According to the reciprocal screw theory, the twists are reciprocal to the wrenches of the kinematic chain. That is, the reciprocal product of the twists and the terminal constraints of the chain are zero.
What is wrench and twist?
A rigid body can be moved from one position to any other by rotation around a line (vector) and translation along that line. This is called a screw motion. The concept of screw can be applied to motion (twist) or to forces and momentum (wrench).
What is screw motion?
A screw motion is a special combination of two simultaneous motions: a linear translations along a vector s and a rotation around a constant axis (screw axis) parallel to s. A screw axis can be represented with a unit vector, s, and an arbitrary point, p, on the axis.
What is screw transformation?
Rigid body displacement can be presented with Chasles’ motion by rotating about an axis and translating along the axis. This motion can be implemented by a screw transformation matrix in the form of either 3×3 dual number matrix or 6×6 transformation matrix that is executed with rotation and translation.