Cartesian space trajectory planner - Simulink

Hi All,

I'm stuck on this part below for an assignment, the first part consisted of me creating a simulink to obtain the desired values of the Puma robot, all is correct as checked and marked.

1. Calculate the controller gains for the independent joint controllers for joints 1-3 (using the parameters given in Table 1). Using the calculated gains to design the feedback controllers for the PUMA and implement the controllers in SIMULINK.

This is where I don't know where to start and I'm stuck...

2. Develop and incorporate a Cartesian space trajectory planner into the controller developed in Step 1. Assuming that the moving range for joints 1 – 3 is [-π, π]. The planner should accept user specified initial and final wrist centre positions, and speed (as percentages of the nominal maximum values – assumed to be 0.3 m/s) and plan a straight-line path for the robot to follow (generate the path every 0.1 second). The joint information will be calculated using inverse kinematics of the robot.

Any guidance would be much appreciated! :)

Below is the simulink that I've already generated.

http://tinypic.com/r/s25vmf/9