Control device of power transmission device and method of setting parameters in a power transmission device

A method of preliminarily setting parameters used in a control processing of a control device of a power transmission device equipped with a primary element which displaces by a driving power of an actuator, and a secondary element coupled to the primary element via an elastic deformation member capable of deforming elastically, and which is provided so as to relatively displace with respect to the primary element by the elastic deformation of the elastic deformation member, and to receive a power transmission from the primary element via the elastic deformation member, the control device controlling a secondary power as a power applied to the secondary element by the power transmission to a desired value, wherein:

• the control device is a device configured to sequentially determine a control input for controlling the driving force of the actuator, with a control processing of a sliding-mode control using a switching function configured taking a deviation between an observed value and the desired value of the secondary power as a first variable component, and a temporal change rate of the deviation as a second variable component, so as to converge the first variable component on a switching hyperplane defined by the switching function to zero;
• the parameter is a gradient of the switching hyperplane in a phase plane taking the first variable component and the second variable component as two coordinate axis components;
• the method comprises a first step of obtaining a plurality of response characteristics data indicating a trajectory of a transition of a set of a value of the first variable component and a value of the second variable component, by an experiment or a simulation of control processing to converge the first variable component from an arbitral value to zero;
• and
• a second step of setting the gradient of the switching hyperplane based on a specific response characteristics data satisfying a predetermined requirement among a plurality of the obtained response characteristics data;
• when a line indicating a first set value preliminarily set according to a first permissible limit value, the first permissible limit value being a preliminarily set permissible limit value of a magnitude of the value of the first variable component, between the first permissible limit value and zero, on the phase plane, is defined as a first set value line, and a line indicating a second set value preliminarily set according to a second permissible limit value, the second permissible limit value being a preliminarily set permissible limit value of a magnitude of the value of the second variable component, between the second permissible limit value and zero, on the phase plane, is defined as a second set value line, then the specific response characteristics data satisfying the predetermined requirement is a response characteristics data satisfying a requirement that the magnitude of the value of the first variable component and the magnitude of the value of the second variable component on the trajectory indicated by the specific response characteristics data are equal to or smaller than the first permissible limit value and equal to or smaller than the second permissible limit value, respectively, and that the trajectory intersects with the first set value line or the second set value line;
• and
• the second step is a step of setting the gradient of the switching hyperplane so that, among intersections between the trajectory indicated by respective specific response characteristics data and the first set value line or the second set value line on the phase plane, a gradient of a line connecting the intersection and an origin of the phase plane coincides with or is approximate to a gradient of a line connecting an intersection satisfying a condition that it is within a preliminarily set requirement range of the gradient of the switching hyperplane, and the origin of the phase plane.