Rectanle Motion By 2 G120C INVERTERS

Dear Experts,

I have a machine which will have a rectangular / circular motion .

It is driven by 2 Motor ( Controlled by 2 G120C Inveter), and i call it M1 (rotation Motor ) and M2 (run forward and backward ) . Please see the attached file for more details.

When the machine run at a circular Mode , only M1 rotate . M2 stop at a stable Position.

But when the machine Run at a Rectangular Mode , M1 rotate and M2 run .

The current postion of M2 is depended on the current Angle of M1 so that the machine can move as a rectanular period. i have 2 Rotary Encoder to measure the Angle of M1 and the position of M2.

i call @1 is the angle 1 of the M1. With the @1, it require x1 (position of M2) so that the machine follow the rectangular period. X1 is calculated value and x' 1 is the actual value (messuared by encoder) .

So my question is that ." Is it possible if i use PID Function to control speed of M2 so that the actual position is closed the calculated position (M1 is constant speed ) ?"

Please give me some advices ?

Thanks