RPC module B

Homeworks of RPC module B

Simone Cremasco VR468971

Exercise B1

For this exercise you need to run

roslaunch homework b1.launch

This will open rviz and load the scara urdf which is available in urdf folder.

'fake_link' was needed in order to attach the end effector frame. This also will bring up 2 services for direct and inverse kinematics. In `srv` folder there is the type definition of services `directKinematics` and `inverseKinematics`. The first receive as input the joint values (j1 to j4) and return a Pose message. The second receive as input the operational space position as x, y, z, phi (rotation on z axis as it's the only possible rotation for a scara) and returns the joint values. The scripts for those services are in `script` folder.

Direct kinematics

To ask for direct kinematics run (change 0 0 0 0 with joint values you want)

rosservice call /directKinematics 0 0 0 0

The result will be

pose: 
  position: 
    x: 0.6
    y: 0.0
    z: -0.09999999999999998
  orientation: 
    x: 0.0
    y: 0.0
    z: 0.0
    w: 1.0

Inverse kinematics

To ask for inverse kinematics run (change 0.6 0 -0.1 0 with x y z phi values you want)

rosservice call /inverseKinematics -- 0.6 0 -0.1 0

The result will be

j1: -0.0
j2: 0.0
j3: -0.0
j4: 0.0

Exercise B2

For this exercise you need to run

roslaunch homework b2.launch

This will activate bring up the necessary scripts for move it. Once loaded run

rosrun homework move

By pressing next when requested you can see the result, here's an animation.

In order we have:

• move to a specific pose
• move to a specific joint state
• follow linear cartesian trajectory
• waypoint trajectory
• trajectory parallel to xy world plane
• box on workspace, trajectory will go over it
• cylinder to ee (not working properly)