Patent ID: 8140288

Claim:
With respect to at least one actuator in a set thereof situated to move a displaceable member, a method for producing a map of compensating force-commands for at least one of force-ripple and side-force in a stroke direction of the at least one actuator, the method comprising: using a selected at least one actuator of the set, displacing the member a series of times over a predetermined increment in a range of motion in the stroke direction, each displacement being from a respective starting position in the range, and each displacement being of a predetermined trajectory having multiple trajectory sections; obtaining, from the displacements, respective force-commands for the selected at least one actuator, for at least one trajectory section; normalizing the section force-commands to a reference section force-command to define a series of respective section compensation ratios for at least one of force-ripple and side-force; mapping the section compensation ratios over the range; and obtaining, from the mapped compensation ratios, a matrix of compensating force-commands sufficient to reduce at least one of force-ripple and side-force.