Jaroslav Matej

In this work we present the shape optimization of a 2000 L water tank placed behind the rear axle of a forestry skidder. The main criterion is the static stability of the vehicle. The purpose of the research is to decrease the impact of the tank on stability of the vehicle. The stability is determined in the form of distances of vectors of a stability triangle and a gravity vector. The tank is divided into small elements and their impact on stability is evaluated independently. Then, the gravity vector, placed in the center of gravity of the vehicle with the tank, combines the gravities of the vehicle and the tank composed of as many elements as required for the desired volume. The Python 3.13 programming language is used to implement the solution. The results for various shapes of the tank are displayed in the form of heatmaps. A slope angle of 20 degrees is used for the analysis. The results show that the longitudinal or lateral stability can be improved by shape modifications of the tank. The most interesting output is the final shape of the tank that improves terrain accessibility of the vehicle. The optimization method is universal and can also be used for different vehicles, tank placements and also auxiliary devices added in general positions.

The presented article presents an innovative solution of a fire-fighting adapter based on the basic hypothesis: to provide sufficient technical support in difficult terrain conditions for water transport logistics in order to quickly prevent the spread and destruction of forest fire. At present, when forest fires begin, it is often quite complicated to provide sufficient technical support for the quick prevention and elimination of fires. This fact is largely eliminated by the designed fire-fighting adapter. The mentioned fire-fighting adapter can be used as a fire-fighting mobile device with a base machine of a forest wheeled skidder (LKT), part of the long-distance transport of water in difficult terrain (lake system), a water tank in difficult terrain with the possibility of filling the Bambi bag with a helicopter, part of the long-distance transport of water in the case of a difficult water source without a forest access road network, and a mobile device for emergency transportation of materials in difficult terrain. In addition to the use for fighting forest fires, the fire adapter can also be used to provide for transport of water for forest nurseries (irrigation), freshly planted areas in the event of prolonged drought, the filling of watering-places for forest animals and filling puddles in the dry season. When designing the supporting frame, we used and imitated the evolutionary approach of nature in the form of generative design. The presented paper deals with the use of modern composite materials in the design of superstructures for base machines, which gradually acquire meaning. The main reason for the increasing use of fiberglass is to achieve higher strength and safer weight reduction. This adapter is designed for forest wheel tractors that reach 40% slope availability, are able to work on the stand area, overcome obstacles and are available in sufficient quantities in all Slovak forest areas.

It is known that tension in the track of a tracked vehicle has a large effect on its driving properties. Simple track tensioning solutions, like track adjusting link assembly, use a one-road wheel motion to govern the motion of a track tensioning element. Thus the track tensioning force is a function of a terrain micro-profile. A logical improvement of this approach is to use all of the road wheels to govern the motion of the track tensioning element. This can be achieved by an auxiliary track tensioning system. This paper analyzes the conceptual track tensioning system governed by a terrain micro-profile. The motion of the track tensioning element is designed as a function of all of the road wheels' motions. A genetic algorithm method, implemented in Java language, is used to find the optimal parameters of the tensioning system and the results are verified via multibody dynamics simulation using the MSC.ADAMS/View system. The paper answers the question of whether the use of all of the road wheels' motions to govern the motion of the track tensioning element can be useful or not. The results indicate that the use of the auxiliary system can decrease the variance of the track tensioning force, in comparison with the track tensioning system without auxiliary tensioning. This means that the value of the track tensioning force is closer to its desired, predefined, and constant value during the whole simulation. The tracked vehicle model that is used is a simplified one and it is intended as a base for specific designs of track tensioning systems with auxiliary tensioning. The results suggest that the system can be used to improve the driving properties of tracked vehicles or robots.

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