A Gaussian wavelet network-based robust adaptive tracking controller for a wheeled mobile robot with unknown wheel slips

Designing a Robust Adaptive Tracking Backtepping Controller Considering Actuator Saturation for a Wheeled Mobile Robot to Compensate Unknown Slippage

“…In other words, there may exist slippage between the wheels and the floor. It is because of slippage that the performance of closed-loop control systems for WMRs deteriorates [7,8,9,10,11]. As a consequence, necessary steps must be taken in order to combat some reduction in tracking control performance due to slippage [12].…”

“…Taking everything into consideration, most of these above control methods have not addressed the tracking control problem in the body coordinate system which is attached to the platform of a WMR, or, more precisely, they were designed in the global coordinate system except for [7,8,9,10,11]. As a consequence, an estimator for obtaining sideslip angle (see Figure 1) [19,20] or an observer estimating the model of friction [21,22] must be needed for designing such controllers.…”

“…In this article, the proposed control approach will confront the serious issue of slippage under the body coordinate system, which is similar to [7,8,9,10,11]. As a result, observers for estimating both the sideslip angle and the friction coefficient are not required anymore.…”

“…• As opposed to [7,8,9,11], a technical solution is used to indirectly avoid actuator saturation and then making this controller suitable for physical limitations in practical applications.…”

“…If the WMR works in the presence of slippage, then the actual linear velocity of the WMR along the longitudinal direction will be expressed in the following illustration [7,8,9,10,11]…”