Design of robot controllers

Computerized nichols' chart for enhancing control design

“…Me' = --= -----=::- ) and this solution exists when -180 0 s v s -90 0 • Note that the magnitude versus phase plot involves the logarithm base 10, while Equations (7) and (8 ) imply the natural logarithm. The set of parametric relationships is then obtained by rewriting with decibels Equations (7) and (8) as:…”

“…CCC 1061-3773/95/040233-08 chols' chart is used as a map to compare the results, and the discrepancy between the two obtained curves therefore appears as a measure of controller nonlinear effects. Today, a renewal of interest around this chart has begun to appear, because modern real-time control approaches-for example, the static feedback linearization method-are now sufficiently good to map exactly nonlinear plants into linear systems [5][6][7][8][9][10][11][12]. Therefore, most features of resulting controllers can be analyzed by means of traditional linear methods, i.e., as the Bode and Nichols plots.…”

Work-space robot controllers

“…where X id is the i-th component of the desired input X. By selecting the i-th output of the system as being force/position servo-controlled, the acceleration in equation (8) should be written as…”

“…where Xd represents the desired acceleration and y represents an additional acceleration term induced by a suitable force. By using equations (8,9), the force to be exerted along the i-th coordinate X t by the manipulator can be introduced into the system by writing it as F id = A'(X)Y-The corresponding F-PSA controllers is now defined by…”

“…This paper introduces generating rules for the derivation of control algorithms to be used in the decoupling method 25 ' 910 when a work space controller is to be built. 8 In the first part, the essential features of a PSA controller are given. The decoupling philosophy of force motion controllers is reviewed in the second part of this paper.…”