Comparison of two robust predictive control strategies for trajectory tracking of flexible-joint robots

Abstract

International audienc

Adaptive fractional-order control of electrical flexible-joint robots: Theory and experiment

“…where d 2 < represents the effect of joint flexibility. Inserting equations (8) and (10) into equation 7, using equation (9), and some mathematical simplification leads to…”

“…2 An observer-based controller for flexible-joints robots has been developed, 3 in which the uncertainties related to motor dynamics are successfully estimated using a disturbance observer. In addition, many other approaches such as nonlinear adaptive control, 4 passivity-based control, 5 adaptive backstepping control, 6 global position-feedback-tracking control, 7 singular perturbation approach, 8 predictive control, 9 adaptive fuzzy approaches, 10 hierarchical sliding-mode control, 11 dynamic surface control, 12 and higher order differential feedback control 13 have been studied. It is worth noting that most of them have ignored the actuator dynamics in their design procedure.…”

Modeling and Preview <inline-formula> <tex-math notation="LaTeX">$H_\infty$</tex-math> </inline-formula> Control Design for Motion Control of Elastic-Joint Robots With Uncertainties

“…3) Anticipation: Beyond well-established two-dof controller structures with feedback and feedforward actions, the anticipation of the trajectory over a finite horizon is a convenient way to increase the tracking precision. Besides model predictive control [13]- [15], two-dof controllers with anticipation (referred to as preview control in the dedicated literature [16]) can be designed using LQG, H 2 or H ∞ frameworks [17]- [21]. In the preview problem, the anticipatory effect is usually materialized by a delay between the anticipated reference and the controlled system inputs.…”