<!DOCTYPE article PUBLIC "-//NLM//DTD JATS (Z39.96) Journal Archiving and Interchange DTD v1.0 20120330//EN" "JATS-archivearticle1.dtd">
<article xmlns:xlink="http://www.w3.org/1999/xlink">
  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Object path modeling with external disturbance compensation and adaptive replanning⋆</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Yurii Zhyshchynskyi</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Serhiy Horiashchenko</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Yehor Solomianyi</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Kherson State Maritime Academy</institution>
          ,
          <addr-line>20, Ushakov ave., 73000, Kherson</addr-line>
          ,
          <country country="UA">Ukraine</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Khmelnytskyi National University</institution>
          ,
          <addr-line>Institutska str., 11, Khmelnytskyi, 29016</addr-line>
          ,
          <country country="UA">Ukraine</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2026</year>
      </pub-date>
      <abstract>
        <p>This study introduces a wind-resilient path planning methodology based on an enhanced “Hybrid Way” algorithm with integrated real-time replanning capabilities. Unlike conventional implementations that neglect environmental disturbances, the proposed framework explicitly incorporates a wind force model into the state transition and cost evaluation functions. The algorithm dynamically adjusts steering angles, motion primitives, and cost weights to mitigate wind-induced trajectory deviations. Furthermore, a continuous replanning mechanism is employed to ensure path optimality and feasibility under rapidly changing wind conditions. The proposed approach is validated through a series of simulation experiments in Python, where it consistently outperforms the baseline “Hybrid Way” in terms of deviation reduction, path smoothness, and travel cost efficiency. The results confirm the method's potential for autonomous ground, marine and aerial vehicles operating in outdoor environments with significant dynamic disturbances.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;path planning</kwd>
        <kwd>wind disturbance</kwd>
        <kwd>real-time replanning</kwd>
        <kwd>autonomous navigation</kwd>
        <kwd>environmental uncertainty</kwd>
        <kwd>dynamic obstacles</kwd>
        <kwd>trajectory optimization</kwd>
        <kwd>simulation</kwd>
        <kwd>algorithms</kwd>
        <kwd>Python</kwd>
        <kwd>1</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        Automated systems for computing the trajectory of objects depend on intricate mathematical
models and algorithms that consider numerous factors influencing the object's motion. These
encompass both external factors, such as wind, gravity, weather, and the object's inherent qualities,
including its mass, size, aerodynamic traits, etc. [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ] Developing these systems necessitates extensive
knowledge in mathematics, physics, computer science, and engineering, alongside experience in
resolving practical navigation and control challenges. A key objective of automated systems is to
guarantee precise trajectory calculations [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ]. This is especially crucial when the object is in
challenging environments or undertaking vital tasks. For instance, in astronautics, proper trajectory
calculation is essential for successful orbit entry, maneuvers, and return to Earth. In the
transportation sector, precise trajectory planning helps avert accidents, ensure passenger security,
and optimize fuel use. Automated systems for calculating object trajectories have widespread
applications across various industries. In transport, such systems are employed to manage autopilots,
unmanned aerial vehicles, rail systems, and marine vessels. In aviation, they offer accurate flight
route planning, automatic aircraft control, and air traffic management. In astronautics, they're used to
compute orbital maneuvers, control spacecraft, and plan missions. In robotics, such systems permit
robots to effectively perform intricate tasks in a dynamic environment.
      </p>
      <p>
        Automating motion calculation procedures permits lessening human involvement in
commonplace and hazardous tasks, boosting the precision and swiftness of task execution, and
diminishing the chance of mistakes. This unveils fresh opportunities for technological advancement
and the betterment of people's lives. Nonetheless, the evolution of such systems demands
considerable efforts and assets, in addition to a complete strategy for tackling automation challenges
[
        <xref ref-type="bibr" rid="ref2 ref3">2, 3</xref>
        ]. The significance of the research subject stems from several key elements. Initially, the
automation of vehicle management procedures, for example automobiles, unmanned aerial vehicles,
and maritime vessels, demands precise and speedy trajectory computations to ensure the safety and
effectiveness of movement [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]. Secondly, within robotics, the exactness of trajectory calculations
establishes the ability of robots to execute complex manipulations in real time, which is crucial for
industrial and service robots in daily routines. Third, in military affairs, accurate prediction of the
trajectory of objects allows to ensure the effectiveness of combat operations and minimize risks.
      </p>
    </sec>
    <sec id="sec-2">
      <title>2. Presenting the main material</title>
      <p>
        Modern automated trajectory calculation systems use a wide range of mathematical models,
including classical methods of mechanics, as well as newer approaches based on artificial intelligence
methods. Classical methods include Newton's equations, which describe the motion of objects under
the influence of forces. Modern approaches include machine learning methods, in particular neural
networks, which are able to learn from large amounts of data and make predictions with high
accuracy [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ].
      </p>
      <p>
        Dynamic models of moving entities are crucial for comprehending and forecasting their conduct
across diverse surroundings. These models enable us to depict the motion of an entity while
considering various physical and mechanical parameters, such as mass, force, acceleration,
environmental resistance, and so on. The advancement and application of dynamic models is very
significant in many areas of science and technology, including transport, aviation, astronautics,
robotics and other areas [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ]. Dynamic models are mathematical or numerical depictions of object
motion that consider both the internal characteristics of the objects and the external impacts
influencing them. They aid in understanding how an object will move under the effect of specific
forces and how its position, velocity, and acceleration will alter over time. Dynamic models rely on
the principles of mechanics, specifically, Newton's three laws, which govern the interplay between
forces and object motion. To precisely portray the movement of objects in real scenarios, it is
essential to consider numerous elements that impact their motion. These could be both internal
properties of the object, such as its mass, dimensions, shape, and external forces, such as gravity,
aerodynamic drag, friction, magnetic fields, etc. Furthermore, it's crucial to consider the conditions of
the surrounding space, which may evolve over time, such as temperature, humidity, pressure, etc. All
these factors together determine the complexity and exactness of dynamic models [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ].
      </p>
      <p>In the transportation industry, dynamic models are used to analyze and optimize the movement of
various vehicles.</p>
      <p>Let us define the position: x =( x , y ), the velocity v = x˙, the direction (course) θ and the angular
velocity ω = θ˙ ˙. The mass is m.</p>
      <p>Fdrive is the control force (from the engine/accelerator), directional — along the course θ;
Basic equations of motion:
where
m v˙ = Fdrive + Fdrag + F fric + F wind + Fobs
(1)
Fdrive = ut [csoinsθθ ], where utis a scalar (force control).</p>
      <p>Fdrag =- cd∥ vrel∥ vrel - the nonlinear aerodynamic drag,
where vrel = v - w ( x , t ) - relative velocity relative to air, cd is the coefficient.</p>
      <p>v
F fric = μ ( x , t ) mg</p>
      <p>∥ v∥ + ε
time friction coefficient, ε - is the regularizer at zero speed.</p>
      <p>, is the dry friction / sliding along the surface; μ ( x , t ) is the
space</p>
      <p>F wind is added as the force from the wind, but if we take into account through vrel in drag, the
explicit addition may be immeasurable; for strong gusts, a stochastic component can be added.</p>
      <p>Angular dynamics (rotation / steering) for a mobile body with limited angular acceleration [6]:
Fobsmis the force of obstacle avoidance.</p>
      <p>I ω˙ = τ steer - cω ω θ =˙ ω
where I is the moment of inertia, τ steeris the steering torque (control uθ), cω is the damping.
Wind is the vector field w ( x , t ).</p>
      <p>We will use stochastic model: gusts as an Ornstein–Uhlenbeck (OU) process [7]:
dw =- κ ( w - w ( x )) dt + σd W t</p>
      <sec id="sec-2-1">
        <title>Variable friction model [9]:</title>
        <p>( x , t )= μ 0 + Δμ ( x )+ η ( t )
This gives time-correlated gusts with amplitude σ and relaxation κ.
Δμ ( x ) is a surface map; η ( t ) is a stochastic fluctuation (dust/moisture).</p>
        <p>Obstacles and detours have three approaches [10, 11]:
1. Repulsion potentials: each static/moving obstacle sets a repulsive field U rep ( r )U , where r is
the distance to the obstacle; force: Fobs =- ∇ U rep. Simple and smooth, but prone to local minima.</p>
        <p>2. Velocity Obstacles / Reciprocal Velocity Obstacles (RVO): for dynamic avoidance at the speed
level (calculate the set of speeds that will lead to a collision).</p>
        <p>3. Local controller - Dynamic Window Approach (DWA) or Model Predictive Control (MPC): at
each step we optimize the control (u_t, u_\theta) for a short horizon taking into account the dynamics
and obstacles. MPC gives better results, but is more computationally expensive.</p>
        <p>Safety and speed constraints:
(2)
(3)
(4)
where vmax ( x , t )can decrease in the area of obstacles or poor friction.</p>
        <p>Example of specific equations (reduced system)
Let us denote the state s = [ x , y , v x , v y , θ , ω ]T
Then</p>
        <p>x˙ = v x
{v˙ y = m1 (ut sinθ - cd∥ v - w∥ ( v x - w x ) - μ ( x , t ) mg ∥ vv∥x + ε + Fobs , y),</p>
        <p>y˙ = v y
v˙ x = m1 (ut cosθ - cd∥ v - w∥ ( v x - w x ) - μ ( x , t ) mg ∥ vv∥x + ε + Fobs , x),</p>
        <p>θ˙ = ω ,
1
ω˙ = I (T steer - cω ω) .</p>
      </sec>
      <sec id="sec-2-2">
        <title>Calculation of the repulsive force:</title>
        <p>1 1 1 2
U rep ( d )= {2 k rep( d - d0 ) , d &lt; d0 , Fobs =- ∇ U rep
0 , d ≥ d0
(5)
(6)
(7)</p>
        <p>In parallel, perform collision checking and, if the repulsive approach is stuck, run a local planner
to rebuild the trajectory.</p>
        <p>For evaluation, use Monte-Carlo simulations or Kalman filter / partial filter (EKF/UKF/Particle) to
estimate the state during movement.</p>
        <p>For deterministic simulations: RK4 with adaptive step dt ; for rigid members (strong friction) —
implicit Euler or semi-implicit scheme. Integration step: choose so that the Courant condition is
fulfilled; for example dt = 0.01…0.1 s for car-like movement.</p>
        <p>Event detection: when approaching an obstacle, perform a check and switch the controller.</p>
        <p>Test extreme cases: zero speed, a sharp gust of wind, a sharp decrease in μ.</p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>3. Development and testing of a program for path optimization</title>
      <p>The developed simulator models the motion of a body along a complex 2D route while
considering:
–</p>
      <p>Wind influence (direction and strength vary over time)
– Surface friction (affects acceleration)
– Obstacles (rectangular, requiring detours)
– Dynamic replanning of the path when conditions change</p>
      <p>The simulation uses an enhanced “Hybrid way” path-planning algorithm, incorporating both
kinematic constraints and environmental disturbances. The program records both the planned
trajectory (ideal path from “Hybrid way”) and the actual trajectory (affected by wind, obstacles, and
dynamics) for comparison.</p>
      <p>The “Hybrid way” algorithm is used to find a path from the start point to the goal.
“Hybrid way” considers the orientation of the vehicle/body and continuous state space, allowing
for realistic turn constraints and smooth paths. The cost function includes:
– Euclidean distance to the goal (heuristic);
– Turning penalties;
– Obstacle avoidance cost;
– Path smoothness factor.</p>
      <p>The simulation proceeds in discrete time steps. At each step the current wind vector is generated
or updated (variable wind). The body’s motion is updated using Newtonian dynamics. Collision
detection is performed with obstacles.</p>
      <p>If a collision or significant deviation occurs, “Hybrid way” is re-run from the current position to
the goal. Movement continues toward the next waypoint [12].</p>
      <p>The program records a CSV log for every run:
– Real motion (affected by wind, collisions, and replanning);
–</p>
      <p>Planned motion (original “Hybrid Way” path without disturbances).</p>
      <p>This allows post-simulation analysis of path deviations, time delays, and energy cost.</p>
      <p>We used Libraries such as “Pygame” for real-time visualization of the simulation. Handles
rendering of the environment, obstacles, wind vector display, and body movement. Provides a game
loop structure for smooth animations.</p>
      <p>In addition, we used “math” (Python Standard Library) for trigonometric calculations (sin, cos,
atan) and coordinate transformations.</p>
      <p>For generates variability in wind direction and strength “random” was used. Randomly positions
obstacles within constraints.</p>
      <p>Saves simulation data into .csv files for later analysis. Each log includes time steps, positions,
orientations, velocities, wind parameters, and replanning flags.</p>
      <p>The program code is written in Python. Parts of the program code, such as the start and parameter
input, are shown in Figure 1.</p>
      <p>When you start the program, a dialog box opens where we can set the parameters for modeling
the object's motion. For example, a 500 kg boat is chosen that has to swim 800 meters. There may be
obstacles and wind in the boat's path.</p>
      <p>After starting the simulation, we will see a field where the object moves and random obstacles that
occur on its path. In addition, the object is affected by a changing wind force. The goal is to find the
optimal path to the final point. The beginning of the movement of the object is shown in Fig. 3. Black
line on object - direction of movement taking into account the erase action.</p>
      <p>The end point of the path for the object is shown in Fig. 4. It shows random obstacles and the green
line is the probable optimal route of the object. The simulation result is shown in a separate window
in figure 5.</p>
      <p>As simulation experiments have shown, critical situations are possible when an object needs to
avoid an obstacle. The critical situations that arose are shown in Fig. 6 when the wind moved the
object to the transition.</p>
      <p>After optimization and adding a safe distance value, we were able to get the object to move
without collisions. An example is shown in Fig. 7 and the simulation result is shown in Fig.8</p>
      <p>Advantages of this approach are given realism then Incorporates continuous dynamics,
disturbances, and physical constraints. In addition, we get flexibility then supports dynamic obstacle
avoidance and environmental changes and visualization is useful for real-time graphical display
helps debug and analyze behavior.</p>
      <p>This simulation framework can be adapted for autonomous ground vehicle navigation, UAV
(drone) path planning under wind disturbances and Robotics motion planning in cluttered
environments. Research in optimal control and adaptive navigation strategies.</p>
    </sec>
    <sec id="sec-4">
      <title>4. Conclusions</title>
      <p>In general, dynamic models of moving objects are a powerful tool for engineers and scientists
working on the development of new technologies and systems. They allow for a deeper
understanding of the physical principles underlying motion and the use of this knowledge to solve
practical problems. With the development of computing and modern modeling methods, the
capabilities of dynamic models are constantly expanding, opening up new prospects for research and
innovation. The development and improvement of dynamic models is an important area of scientific
research that will contribute to further progress in the creation of new technologies and systems that
improve the quality of life and safety of people.</p>
      <p>Development and evaluation of a “Hybrid Way” path planning framework integrated with
realtime replanning capabilities under wind disturbance conditions was created. The proposed approach
effectively combines the deterministic search characteristics of “Hybrid Way” with adaptive
trajectory updates, enabling the system to maintain feasible and efficient navigation in dynamic and
uncertain environments.</p>
      <p>Despite the fact that the object traveled 1.8 times longer than planned, we did not receive any
collisions. Simulation results in demonstrate that the method achieves robust path tracking while
minimizing deviations caused by lateral wind forces. The incorporation of environmental feedback
allows the planner to proactively adjust trajectories, ensuring collision avoidance and maintaining
operational safety. Compared to static planning, the hybrid approach exhibits superior adaptability,
particularly in scenarios with fluctuating environmental conditions and dynamic obstacles.</p>
    </sec>
    <sec id="sec-5">
      <title>Declaration on Generative AI</title>
      <p>The authors have not employed any Generative AI tools.
[6] Kelly A, Nagy B. Reactive Nonholonomic Trajectory Generation via Parametric Optimal
Control. The International Journal of Robotics Research. 2003;22(7-8):583-601.
doi:10.1177/02783649030227008
[7] LaValle, S. M. (2006). Planning algorithms. Cambridge University Press.</p>
      <p>https://doi.org/10.1017/CBO9780511546877
[8] Kelly, A., &amp; Nagy, B. (2003). Reactive nonholonomic trajectory generation via parametric
optimal control. The International Journal of Robotics Research, 22(7–8), 583–601.
https://www.cs.cmu.edu/~alonzo/pubs/papers/ijrr02TrajGen.pdf
[9] Cora ÖN, Akkök M, Darendeliler H. Modelling of variable friction in cold forging. Proceedings
of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology.
2008;222(7):899-908. Fossen, T. I. (2011). Handbook of marine craft hydrodynamics and motion
control. John Wiley &amp; Sons. https://doi.org/10.1002/9781119994138
[10] Automatic diagnostic device with measurement of distances to damages by the combined
pulsephase method Janusz Musiał, Kostyantin Horiashchenko, Serhiy Horiashchenko and Mikołaj
Szyca, MATEC Web of Conferences 351, 01008 (2021)
https://doi.org/10.1051/matecconf/202135101010
[11] S. Horiashchenko, O. Paraska, K. Horiashchenko, V. Onofriichuk, O. Synyuk and V. Pavlenko,
"Mechatronic System for Management and Control of a Device for Applying a Polymer
Coating," 2023 IEEE 5th International Conference on Modern Electrical and Energy System
(MEES), Kremenchuk, Ukraine, 2023, pp. 1-5, doi: 10.1109/MEES61502.2023.10402550
[12] Arslan, M. (2016). Obstacle detection and pathfinding for mobile robots (Master’s thesis, Near East
University, Graduate School of Applied Sciences). Retrieved from
https://vixra.org/pdf/1705.0027v1.pdf</p>
    </sec>
  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          [1]
          <string-name>
            <given-names>Y.</given-names>
            <surname>Haartsen</surname>
          </string-name>
          ,
          <string-name>
            <given-names>R.</given-names>
            <surname>Aalmoes</surname>
          </string-name>
          and
          <string-name>
            <given-names>Y. S.</given-names>
            <surname>Cheung</surname>
          </string-name>
          ,
          <article-title>"Simulation of unmanned aerial vehicles in the determination of accident locations," 2016 International Conference on Unmanned Aircraft Systems (ICUAS), Arlington</article-title>
          ,
          <string-name>
            <surname>VA</surname>
          </string-name>
          , USA,
          <year>2016</year>
          , pp.
          <fpage>993</fpage>
          -
          <lpage>1002</lpage>
          , doi: 10.1109/ICUAS.
          <year>2016</year>
          .
          <volume>7502548</volume>
          .
        </mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation>
          [2]
          <string-name>
            <given-names>O.</given-names>
            <surname>Matsebe</surname>
          </string-name>
          ,
          <string-name>
            <given-names>C.M.</given-names>
            <surname>Kumile</surname>
          </string-name>
          ,
          <string-name>
            <given-names>N.S.</given-names>
            <surname>Tlale</surname>
          </string-name>
          ,
          <article-title>A Review of Virtual Simulators for Autonomous Underwater Vehicles (AUVs)</article-title>
          ,
          <source>IFAC Proceedings Volumes</source>
          , Volume
          <volume>41</volume>
          ,
          <string-name>
            <surname>Issue</surname>
            <given-names>1</given-names>
          </string-name>
          ,
          <year>2008</year>
          , Pages
          <fpage>31</fpage>
          -
          <lpage>37</lpage>
          , ISSN 1474-6670, ISBN 9783902661357, https://doi.org/10.3182/20080408-3-IE-
          <volume>4914</volume>
          .
          <fpage>00007</fpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref3">
        <mixed-citation>
          [3]
          <string-name>
            <surname>Dolgov</surname>
            ,
            <given-names>D.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Thrun</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Montemerlo</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Diebel</surname>
            ,
            <given-names>J.</given-names>
          </string-name>
          (
          <year>2008</year>
          ).
          <article-title>Practical search techniques in path planning for autonomous driving</article-title>
          .
          <source>Annals of Mathematics and Artificial Intelligence</source>
          ,
          <volume>55</volume>
          (
          <issue>3-4</issue>
          ),
          <fpage>293</fpage>
          -
          <lpage>316</lpage>
          . https://ai.stanford.edu/~ddolgov/papers/dolgov_gpp_stair08.pdf
        </mixed-citation>
      </ref>
      <ref id="ref4">
        <mixed-citation>
          [4]
          <string-name>
            <surname>Pivtoraiko</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Kelly</surname>
            ,
            <given-names>A.</given-names>
          </string-name>
          (
          <year>2005</year>
          ).
          <article-title>Efficient constrained path planning via search in state lattices</article-title>
          .
          <source>In Proceedings of the 8th International Symposium on Artificial Intelligence, Robotics and Automation in Space (i-SAIRAS)</source>
          (pp.
          <fpage>1</fpage>
          -
          <lpage>8</lpage>
          ). https://www.cs.cmu.edu/~alonzo/pubs/papers/isairas05Planning.pdf
        </mixed-citation>
      </ref>
      <ref id="ref5">
        <mixed-citation>
          [5]
          <string-name>
            <given-names>H. C.</given-names>
            <surname>Pangborn</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M. A.</given-names>
            <surname>Williams</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J. P.</given-names>
            <surname>Koeln</surname>
          </string-name>
          and
          <string-name>
            <given-names>A. G.</given-names>
            <surname>Alleyne</surname>
          </string-name>
          ,
          <article-title>"Graph-based hierarchical control of thermal-fluid power flow systems," 2017 American Control Conference (ACC), Seattle</article-title>
          , WA, USA,
          <year>2017</year>
          , pp.
          <fpage>2099</fpage>
          -
          <lpage>2105</lpage>
          , doi: 10.23919/ACC.
          <year>2017</year>
          .
          <volume>7963262</volume>
          .
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>