Presentation robotic systems

9 Computers and Automation Engineering – “Robotic Systems”




Robotic Systems
Trajectory generation

, Introduction - Trajectory
 Describes the desired motion of a
Initial
position

{T}
manipulator in multi-dimensional
End

space. Tr




 Refers to a time history of position,
velocity, and acceleration for each {S}

degree of freedom (i.e. joint variable).
Joint’s Parameter
Trajectory


Robotic 20-21 / Dr. Aghiad Kh. (email: )

, Initial
position

Introduction - In executing a trajectory, {T}



 Generation occurs at run time;
 A manipulator moves from its initial
position to a desired goal position in a
smooth manner.
{S}


 The trajectory points are computed at a Joint’s Parameter


certain rate, called: The path-update rate,
Trajectory

𝑓𝑒𝑟𝑞𝑢𝑒𝑛𝑐𝑦 𝐻𝑧 ≡ 𝑝𝑒𝑟𝑖𝑜
(60-2000 Hz). 60 𝐻𝑧 ≡ 0.01666666666

2000 𝐻𝑧 ≡ 0.0005 𝑝𝑠
Robotic 20-21 / Dr. Aghiad Kh. (email: )

, Introduction - A path description 𝑇𝑖𝑛𝑖𝑡𝑖𝑎

 Is to give a sequence of desired via points (intermediate
points between the initial and final positions).
 I.e., the tool frame must pass through a set of intermediate
positions and orientations as described by the via points.
 Each path point is usually specified in terms of a desired
{S
position and orientation of the tool frame, {T}, relative to }

the station frame, {S}.
 Each of these via points is "converted" into a set of desired
joint angles by application of the inverse kinematics.
Robotic 20-21 / Dr. Aghiad Kh. (email: )