Challenges to national defence in contemporary geopolitical situation

The paper deals with the investigation of parameters and influences for the system of evaluating the trafficability of vehicles through the terrain. Trafficability is one of the main aspects to ensure the movement of own troops, which falls into the main task of the Engineer troops - combat and general engineering support for all types of activities and operations of the army. Trafficability is the ability of a vehicle to move in rough terrain or on damaged roads and depends on many factors. The most used tool for determining trafficability in the Czech Army is the penetrometer. It is the PT-45 penetrometer, which is described in the Žen 2-16 Military Roads and Ways and the main evaluation criterion is the weight of the vehicle. Within the framework of international cooperation, soldiers encounter the manual FM 5-430-00-1 Design and design of roads, airports and heliports during events on the battlefield - road design, which works with a cone penetrometer and evaluates the throughput of the vehicle based on other factors such as properties of tires, ground clearance, engine power, etc. Inaccurate or incorrect evaluation leads not only to a stop the engagement of individual vehicles, but the entire convoy, which in terms of the operational task stops the manoeuvre and may lead to failure of the order. Therefore, it is important to know what parameters and influences have a fundamental influence on the system of evaluating the trafficability of vehicles, whether it would not be appropriate to add other aspects that will lead to higher accuracy of measurement, or, conversely, to exclude some. In solving this task, the authors decided to use the above-mentioned manuals and their evaluation systems. The objectives of the paper were achieved by analysis and calculations of individual parameters listed in these regulations, which affect the trafficability through the terrain, so that the degree of dependence is determined. It was found that some parameters have a major impact on trafficability and it is necessary to take into account even a slight change in these values. In contrast, other parameters are negligible as a result. These calculations confirm the suitability of updating the evaluation system for the telescopic penetrometer PT-45 to determine the trafficability of vehicles, so that it is possible to obtain more accurate results of measured values of the Czech army in the performance of tasks.