Trajectory tracking of an uncertain wheeled mobile robotic manipulator with a hybrid control approach

Abstract

In this paper, a novel hybrid control approach is used for trajectory-tracking control of wheeled mobile robotic manipulators (WMRMs) in the presence of model uncertainties and external disturbances. Due to the existence of nonholonomic constrains in wheeled mobile robots, the proposed controller should be able to tackle the challenge of underactuation in such systems. To attain this objective, the dynamic equations of motion for a WMRM are derived in closed form using the Gibbs-Appell (G-A) formulation, which is an efficient method for obtaining the dynamic motion equations of nonholonomic systems. Then, a novel control scheme is developed which is both optimal and robust and which enjoys updated gains under an adaptive law. In this regard, to benefit from the advantages of two distinct methods, a high-order sliding mode control (HOSMC) is employed as a robust controller with the aim of handling system uncertainties and a state-dependent Riccati equation (SDRE) is used as a nonlinear optimal controller. In order to systematically deal with system uncertainties and to avoid the manual calculation of the upper bound of uncertainties, the gain of HOSMC is updated via an adaptive law. The most important advantage of this novel approach over the existing methods is that not only is it robustly stable against external disturbances when controlling an uncertain nonlinear system but also optimal for a predefined quadratic cost function. Lyapunov stability theory is employed to verify the stability of the proposed controller. Finally, to demonstrate the superiority of this novel controller, computer simulation results for a WMRM are compared with those of an adaptive sliding mode controller. It can be observed that the proposed hybrid control approach is capable of optimizing control inputs while achieving stability for a WMRM in the presence of model uncertainties.

Model-based robust servo control for permanent magnet synchronous motor with inequality constraint

“…In the actual operation of the motor, the parameters will change with the motor operating conditions or environmental changes, and a large range of parameter mismatch may occur. At this time, MPC only relies on more accurate model parameters, which may not be able to maintain good control performance [22,23].…”

Implementation of a robust data-driven control approach for an ommi-directional mobile manipulator based on koopman operator

“…Viet et al 3 has proposed a tracking control method for a three-wheeled OMM considering disturbance and friction, in which sliding mode controller was employed. A hybrid control strategy for trajectory-tracking control of wheeled mobile robotic manipulators was proposed by Shafei et al 4 in the presence of model uncertainties and external disturbances. A robust neural network-based sliding mode controller was designed by Xu et al 5 for trajectory tracking problem for a redundantly actuated OMM in the presence of uncertainties and disturbances.…”

A novel recursive formulation for dynamic modeling and trajectory tracking control of multi-rigid-link robotic manipulators mounted on a mobile platform

“…The great mobility of the wheeled base and the dexterous manipulation abilities of the mechanical arm boost the operational functionality of these types of robotic systems, so they are extensively used in various applications. 1–3 However, the dynamic modeling of such systems is further complicated by the effects of dynamic coupling between their nonholonomic mobile platform and holonomic mechanical arm. Furthermore, by increasing the number of links in a mobile robotic manipulator, the manual derivation of the system’s dynamic motion equations becomes more difficult and time-consuming.…”