Motion control of an oscillatory-base manipulator using sliding mode control via rotating sliding surface with variable-gain integral control

Abstract

In this paper, we present a motion control method of oscillatory-base manipulators, which are associated with mechanical systems installed on vessels or ocean structures. The typical property of such systems is strong and persistent disturbance due to the base oscillation to be overcome. Therefore, we attempt to exploit the sliding mode control (SMC) concept which is known to be a powerful tool to develop a robust control system against disturbances and model uncertainties. Specifically, we propose a novel approach based on SMC by introducing a nonlinear sliding surface with variable-gain integral control. We address control system design and stability analysis for the proposed SMC, and demonstrate its control performance by simulations. The results show that the proposed control method can achieve successful control performance for oscillatory-manipulators and further exhibits advantageous features with respect to control performance and control inputs when compared with the conventional SMC.

Robust Motion Control of an Oscillatory-Base Manipulator in a Global Coordinate System

“…As future works, with respect to the control problem discussed here, the other typical robust control methods, such as sliding mode control which we have started working on [19], and disturbance observers will be examined and compared. Furthermore, in order to accommodate the case where the assumption of known frequency range is hard to be available, e.g., when the ship travels with constantly and largely changing velocity and/or heading, we will investigate some adaptive control scheme according to a variation of the frequency range.…”

“…The preliminary version of this paper [14] tackled the motion control in global coordinates of an oscillatory-base manipulator by extending the control design method for local-coordinate problems and demonstrated its effectiveness by conducting simulations. Meanwhile, we attempted to apply sliding mode control, which is also known to be powerful to disturbance rejection and robust control problems [9], [15]- [18], and obtained preliminary results by simulations [19]. The objectives of this paper are as follows: 1) to demonstrate the proposed H ∞ control-based approach for such control problems in global coordinates in more detail than that in [14], specifically with not only evaluations via simulations but also ones by conducting experiments with our developed experimental apparatus; 2) to present robustness evaluations with respect to physical parametric perturbations via experiments and mathematical analyses using our proposed machinery, which is based on the state-dependent coefficient form [20] and applicable to a wider class of systems than that proposed in [20] which is exclusive for symmetric systems.…”

Robust Motion Control of Oscillatory-Base Manipulators

“…In [42], we proposed a novel nonlinear sliding surface with the variable-gain integral control. The proposed SMC provides superior performance to the conventional SMC in terms of transient performance and less required control inputs.…”

“…On the other hand, its disadvantages are common shortcomings of SMC, that is, the gaps between in theory and in practical applications mainly due to discontinuous switching control inputs. In [42], only preliminary results have been given.…”

Estimation of ship oscillation subject to ship speed variation using an algorithm combining H<inf>&#x221E;</inf> and Kalman Filters

“…In the literature [1]- [4], an H ∞ control-based approach and a sliding mode control-based one have been proposed, and their effectiveness have been shown respectively. However, those methods require the estimates of the base oscillation, the accuracy of which will influence the reference commands to be tracked by the control systems and correspondingly the control performances.…”