Rafal Szczepanski

Dr. Rafal Szczepanski

orcid

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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29 June 2023 in IEEE Robotics and Automation Letters
Verified
Journal Article
Closed access
Rafal SzczepanskiRafal Szczepanski
Rafal Szczepanski
This letter proposes a novel local path planning algorithm called Safe Artificial Potential Field (SAPF). The algorithm uses the attractive potential for goal reaching as the original one. However, the repulsive potential is replaced by a general obstacle potential, equal to repulsive potential, vortex potential, or their superposition. Moreover, the analytical tuning procedure of SAPF is described in this letter. The proposed algorithm has been compared to the original Artificial Potential Field (APF), Vortex APF (VAPF), and Dynamic Window Approach (DWA). The comparison has been provided using both, simulational and experimental validation. The SAPF allows to avoid simple local minima, keep safety distance from obstacles and move through narrow corridors. The obtained results in the form of videos are attached as supplementary files.

11 April 2022 in IEEE Access
Verified
Journal Article
Open access
Rafal SzczepanskiRafal Szczepanski
Rafal Szczepanski
Tomasz TarczewskiTomasz Tarczewski
Tomasz Tarczewski
Krystian ErwińskiKrystian Erwiński
Krystian Erwiński
Energy efficiency is one of the most important parameters in transportation electrification. It allows to improve the production rate due to longer operation without charging or decrease the cost related to transportation. To provide collision-free operation in unknown or various environment, the local path planning algorithm should be considered. An Artificial Potential Field (APF) algorithm is commonly used for this task, however it provides unsmooth and oscillating motion of autonomous ground vehicle (AGV), and is prone to being trapped in a local minimum, e.g, dead-end. In such a case, the energy used to achieve the goal position is higher than necessary. In this paper, the energy-efficient local path planning algorithm is proposed. Future movement prediction has been introduced to APF to allow AGV to bypass obstacles in advance. A novel method for local minimum avoidance is introduced. It is based on placement of virtual obstacles called top quarks in critical areas. These obstacles provide additional repulsive force for the APF based path planner. Considering the predicted stagnation-free path of the AGV, the new temporary goal for APF is selected. Such a combination allows to reduce traveled route length, improve its smoothness, and bypass local minima. The proposed Predictive Artificial Potential Field (PAPF) algorithm has been examined using Husarion ROSbot 2.0 PRO mobile robot, and the obtained results in form of videos are also attached as supplementary files. In comparison to original APF, the proposed path planning algorithm allows to reduce the used electric power by 21.4 %. PAPF provided a shorter path by up to 8.73 % and shorter time to reach the goal position by up to 40.23 %. The movement of the AGV is also much smoother in a case of usage of the proposed algorithm, and the proposed top quarks -based local minimum avoidance mechanism allows to bypass the local minima.

14 October 2021 in Energies
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Journal Article
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Rafal SzczepanskiRafal Szczepanski
Rafal Szczepanski
ABArtur Bereit
Artur Bereit
Tomasz TarczewskiTomasz Tarczewski
Tomasz Tarczewski
Mobile robots in industry are commonly used in warehouses and factories. To achieve the highest production rate, requirements for path planning algorithms have caused researchers to pay significant attention to this problem. The artificial potential field algorithm, which is a local path planning algorithm, has been previously modified to obtain higher smoothness of path, to solve the stagnation problem and to jump off the local minimum. The last itemized problem is taken into account in this paper—local minimum avoidance. Most of the modifications of artificial potential field algorithms focus on a mechanism to jump off a local minimum when robots stagnate. From the efficiency point of view, the mobile robot should bypass the local minimum instead of jumping off it. This paper proposes a novel artificial potential field supported by augmented reality to bypass the upcoming local minimum. The algorithm predicts the upcoming local minimum, and then the mobile robot’s perception is augmented to bypass it. The proposed method allows the generation of shorter paths compared with jumping-off techniques, due to lack of stagnation in a local minimum. This method was experimentally verified using a Husarion ROSbot 2.0 PRO mobile robot and Robot Operating System in a laboratory environment.

1 October 2019 in Applied Soft Computing
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Journal Article
Closed access
Rafal SzczepanskiRafal Szczepanski
Rafal Szczepanski
Tomasz TarczewskiTomasz Tarczewski
Tomasz Tarczewski
LGLech M. Grzesiak
Lech M. Grzesiak

30 May 2022 in Engineering Applications of Artificial Intelligence
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Journal Article
Open access
Rafal SzczepanskiRafal Szczepanski
Rafal Szczepanski
Krystian ErwińskiKrystian Erwiński
Krystian Erwiński
MTMateusz Tejer
Mateusz Tejer
ABArtur Bereit
Artur Bereit
Tomasz TarczewskiTomasz Tarczewski
Tomasz Tarczewski

13 June 2020 in Energies
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Journal Article
Open access
PDF file
Rafal SzczepanskiRafal Szczepanski
Rafal Szczepanski
Marcin KaminskiMarcin Kaminski
Marcin Kaminski
Tomasz TarczewskiTomasz Tarczewski
Tomasz Tarczewski
The state feedback controller is increasingly applied in electrical drive systems due to robustness and good disturbance compensation, however its main drawback is related to complex and time consuming tuning process. It is particularly troublesome for designer, if the plant is compound, nonlinear elements are taken into account, measurement noise is considered, etc. In this paper the application of nature-inspired optimization algorithm to automatic tuning of state feedback speed controller (SFC) for two-mass system (TMS) is proposed. In order to obtain optimal coefficients of SFC, the Artificial Bee Colony algorithm (ABC) is used. The objective function is described and discussed in details. Comparison with analytical tuning method of SFC is also included. Additionally, the stability analysis for the control system, optimized using the ABC algorithm, is presented. Synthesis procedure of the controller is utilized in Matlab/Simulink from MathWorks. Next, obtained coefficients of the controller are examined on the laboratory stand, also with variable moment of inertia values, to indicate robustness of the controller with optimal coefficients.