Controlling a multi-articulated robot in backward movement using an adaptive controller

This work proposes an adaptive dynamic controller for a multi-articulated robotic vehicle, which can be a multi-trailer truck in backward movements or even a tractor vehicle pushing passive trailers in agricultural applications. These articulated vehicles should navigate avoiding collisions between the elements of the composition (a situation referred to as jackknife), which would preclude the vehicle to continue navigating. The vehicle modeling is shown, considering a composition with n trailers, and the model is used to design the proposed controller. To avoid drift in the dynamic parameters whose values are updated along the navigation two strategies were implemented and compared, which are the so-called sigma modification and a dead-zone for the velocity tracking error, so that the parameter updating is canceled whenever such an error is inside the dead-zone. Results of real experiments are also shown, for multi-articulated vehicles with one and two trailers, which validate the proposed strategy, allowing claiming that the proposed adaptive controller is efficient to guide the vehicle.