## 1 Introduction
As a result of the modifications employed, the mechanical structure of the TMR chassis was enlarged, and its electrical and electronic components were replaced, including wheel rotation sensors and the laser scanner. In preparation for testing the robot in an outdoor environment, the implementation of control algorithms was realized. A high-level controller responsible for generating a reference trajectory and stabilizing the robot's position along this trajectory and a low-level controller responsible for executing set speeds through the drive motors were considered. The specific type of algorithm was selected for high-level controller taking into account a number of methods proposed in the literature. In this case, an advanced method derived from geometric non-linear control techniques was chosen, using the so-called transverse functions (TFs) [21]. It should be noted that it is a universal smooth stabilizer that enables practical stabilization along any bounded trajectory including a fixed point. Although there are applications of this approach to mobile robot control, i.e., [22; 23], not many papers deal with the experimental validation of this approach. Works such as [24; 25] show experiments with a mobile robot in an indoor environment. The motion control algorithm considered in this article was developed with a modified method of tuning the transverse function parameters; this method was introduced in [3], where a nonholonomic manipulator control was considered. The TF algorithm performs stabilization of the robot's position on a trajectory that was generated using the time elastic band algorithm [26]. This provided a practical and fast way to prototype different trajectories of the robot's traversal using the passage points, which significantly facilitates the implementation of field tests. The high-level control algorithm involving transverse functions and time elastic band methods was implemented on the robot's onboard computer, and integration with the low-level controller responsible for stabilizing electric motors operation was carried out. The low-level controller was implemented using an industrial PLC, which is also responsible for the safety of the robot's operation. Consequently, the paper also presents basic issues related to the implementation of a low-level controller. In addition, basic information on the robot's design is presented. This paper is focused both on theoretical and practical aspects of motion control in mobile robotics. In particular, the design of a novel control architecture that enables the operational deployment of the rebuilt towing mobile robot in outdoor tests is discussed. In this paper, the architecture is understood as the specific solution that integrates a non-standard motion controller with the TEB planner, using modern industrial automation components, rather than as a new paradigm for how different system blocks are interconnected. The publication presents the application of modern techniques for implementing robot control architecture using industrial PLCs. Few publications in the field of mobile robot control cover these issues in detail. In many cases, this is due to the use of mobile robots produced by the robotics industry for research, which do not provide such data. An important contribution of the publication is also the presentation of the details of the implementation of the control algorithm at the level of servo drives and at the level of the responsible high-level algorithm. To implement the high-level control algorithm, the transverse function algorithm is used together with the time elastic band method. This solution allows a unified approach for tracking trajectories generated through transit points to be achieved. To the best of the authors' knowledge, this represents the first synthesis of the transverse function algorithm together with the time elastic band method.