I have a system like shown in the diagram
where 2 robots having differential drive are physically constrained together. Traditionally for a single robot, we find the Instantaneous center of curvature (ICC) by equating the "omega" for both wheels. That would work since there are 2 equations (the relationship between the wheel velocities and angular velocity) and 2 unknowns (the distance of ICC from the center of the wheels and the angular velocity). However, in my system, there will be 4 equations and 2 unknowns. So should I solve it as an over-determined system? Or should I only consider the extreme cases, i.e. left most wheel speed for the left robot and rightmost wheel speed for the right robot? If neither approach is correct then how do I proceed?