Monthly Archives: August 2012

Visual Servoing –part II( Planar Arm Trajectory Planning )

In the second part of VS project to implement a two-link planar arm and to make it interact with other objects such as ball, obstacles and goal, we need to estimate object position in real world coordinates. It is done using curve (surface) fitting techniques to map from pixel frame to real world Cartesian coordinate.

For the purpose of making the arm move from current to desired position with fixed velocity or acceleration we need to solve Trajectory Planning problem. For this purpose we consider three approaches. Position Control is the first one in which we define several via points and solve Inverse Kinematic equations.The second approach is Velocity Control that utilizes Inverse Jacobian to maintain end effector velocity in proper way. In the third approach that is a combination of previous ones, the linear velocity is fed to Inverse Jacobian so as to compensate position error and avoid loss of efficiency near the singularity points.