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1

Calibration by diffeomorphisms of robot manipulator kinematics: a novel approach

Orozco Roberto, Ratajczak Adam

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2025

|

Vol. 73, nr 2

art. no. e153230

EN

Our paper presents a nonparametric data-driven technique that can enhance the accuracy of robot kinematics models by reducing geometric and nongeometric inaccuracies. We propose this approach based on the theory of singular maps and the Large Dense Diffeomorphic Metric Mapping (LDDMM) framework, which has been developed in the field of Computational Anatomy. This framework can be thought of as a method for identifying nonlinear static models that encode a priori knowledge as a nominal model that we deform using diffeomorphisms. To tackle the kinematic calibration problem, we implement Calibration by Diffeomorphisms and obtain a solution using an image registration formalism. We evaluate our approach via simulations on double pendulum robot models, which account for both geometric and nongeometric discrepancies. The simulations demonstrate an improvement in the precision of the kinematics results for both types of inaccuracies. Additionally, we discuss the potential application of physical experiments. Our approach provides a fresh perspective on robot kinematics calibration using Calibration by Diffeomorphisms, and it has the potential to address inaccuracies caused by unknown or difficult-to-model phenomena.

2

Projekt sportowego pistoletu maszynowego MPM 9 „Bohr”. Część II - Podstawowe obliczenia konstrukcyjne

Hryniewicz Michał, Magier Mariusz

Problemy Techniki Uzbrojenia

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2024

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R. 53, z. 170

7--37

PL

Celem niniejszej pracy było zaprojektowanie sportowego pistoletu maszynowego na podstawie przeglądu obecnych rozwiązań konstrukcyjnych wykorzystywanych w tego typu broni oraz stworzenie wstępnych założeń technicznych. W zakres pracy wchodził wybór naboju zasilającego pistolet maszynowy, dobór długości lufy, obliczenie średnicy zewnętrznej lufy, dobór masy zamka i sprężyny powrotnej oraz obliczenia kinematyki zamka, wykonanie modelu funkcjonalnego z wykorzystaniem techniki addytywnej, sprawdzenie poprawności działania mechanizmów broni oraz wskazanie możliwych usprawnień konstrukcyjnych. W części II dokonano zaprezentowano podstawowe obliczenia konstrukcyjne pistoletu maszynowego MPM 9 „Bohr”.

EN

The aim of this work was to design a sports submachine gun based on a review of current design solutions used in this type of weapon and to create preliminary technical assumptions. The scope of work included the selection of a cartridge for the submachine gun, the selection of the barrel length, the calculation of the outer diameter of the barrel, the selection of the mass of the bolt and the return spring as well as the calculation of the bolt kinematics, and the preparation of a functional model using the additive technique, checking the correct operation of the weapon's mechanisms and indicating possible design improvements. Part II presented the basic design calculations of the MPM 9 "Bohr" submachine gun.

3

Projekt sportowego pistoletu maszynowego MPM 9 „Bohr”. Część I –przegląd istniejących konstrukcji, wstępne założenia techniczne

Hryniewicz Michał, Magier Mariusz

Problemy Techniki Uzbrojenia

|

2024

|

R. 53, z. 169

47--62

PL

Celem niniejszej pracy było zaprojektowanie sportowego pistoletu maszynowego na podstawie przeglądu obecnych rozwiązań konstrukcyjnych wykorzystywanych w tego typu broni oraz stworzenie wstępnych założeń technicznych. W zakres pracy wchodził wybór naboju zasilającego pistolet maszynowy, dobór długości lufy, obliczenie średnicy zewnętrznej lufy, dobór masy zamka i sprężyny powrotnej oraz obliczenia kinematyki zamka, wykonanie modelu funkcjonalnego z wykorzystaniem techniki addytywnej, sprawdzenie poprawności działania mechanizmów broni oraz wskazanie możliwych usprawnień konstrukcyjnych. W części I zawarto przegląd istniejących konstrukcji sportowych pistoletów maszynowych oraz sformułowano wstępne założenia techniczne do projektowania.

EN

The aim of this work was to design a sports submachine gun based on a review of current design solutions used in this type of weapon and to create preliminary technical assumptions. The scope of work included the selection of a cartridge for the submachine gun, the selection of the barrel length, the calculation of the outer diameter of the barrel, the selection of the mass of the bolt and the return spring as well as the calculation of the bolt kinematics, the creation of a functional model using the additive technique, checking the correct operation of the weapon's mechanisms and indicating possible design improvements.Part I contains an overview of existing designs of sports submachine guns and formulates preliminary technical assumptions for design.

4

Arduino-based implementation of kinematics for a 4 DOF robot manipulator using artificial neural network

Rashid Zaid Hikmat, Sarhan Riyadh Ahmed, Hassan Mohammed Salih

Diagnostyka

|

2024

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Vol. 25, No. 1

art. no. 2024114

EN

Real-time motion control is basically dependent on robot kinematics analysis where there is no unique solution of the inverse kinematics of serial manipulators. The predictive artificial neural network is a powerful one for finding appropriate results based on training data. Therefore, an artificial neural network is proposed to implement on Arduino microcontroller for a 4-DOF robot manipulator where the inverse kinematics problem was partitioned to suit the low specification of the board CPU. With MATALB toolbox, multiple neural network configuration based were trained and experienced for the best fit of the dimensionless feedforward data that is obtained from the forward kinematics of reachable workspace with average MSE of 6.5e-7. The results showed the superior of the proposed networks reducing the joints error by 90 % at least with comparing to traditional one. An Arduino on-board program was developed to control the robot independly based on pre validated parameters of the network. The experimental results approved the proposed method to implement the robot in real time with maximum error of (± 0.15 mm) in end effector position. The presented approach can be applied to achieve a suitable solution of n-DOF self-depend robot implementation using micro stepping actuators.

5

Kinematic calibration of a lightweight manipulator for medical applications

Arent Krzysztof, Kurnicki Adam, Portasiak Piotr, Stańczyk Bartłomiej

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2024

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Vol. 72, nr 6

art. no. e151381

EN

The paper presents a kinematics calibration procedure for a lightweight manipulator designed for medical applications. They comprise improving the dexterity of a dysfunctional arm of a handicapped patient in an electric wheelchair as well as supporting biopsies and surgeries. Consequently, there are several manipulator distinguishing features of the manipulator design that are relevant to kinematics calibration. In particular, these are: a small area in the workspace within which the end-effector operates, affordability for non-commercial users, a delicate, dexterous design. In this context we propose a specialized procedure that features a low cost calibration tool enabling the end-effector to reach the correct positions for data acquisition. The key parameters of the calibration tool were obtained by applying two techniques of numerical analysis, workspace clustering and arbitrary choice, and subsequent experimental verification. The procedure exploits classical results concerning the kinematics calibration and is empirically verified by comprehensive simulation and experimental studies.

6

Architecture of time: from motion picture to computer animation

Kwiatkowska Ada

Architectus

|

2023

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Nr 4 (76)

117--126

EN

The architecture of the digital era, exploring the dimension of time, refers to the concept of so-called time-based art. Present computer technologies allow one to simulate the space-time transformation of architectural objects connected with observer’s movement and to create dynamic movable spatial structures by applying smart materials and technologies to architecture. The purposes of the research are to analyse the influence of the concept of time on the shaping of architectural forms and the directions of the development of architectural forms determined by technologies discovered during the industrial and information revolutions (film techniques, computer visualisations, simulations, and animations). Based on the structural analysis of dynamic mutual relations between the observer, the architectural object, and the context, connected with comparative and critical analysis of modern trends, different types of architecture of time are distinguished. These types are derivatives of the expression of time in three-dimensional space and assumptions related to the degree of changeability and dynamics of the spatial structures (kinaesthetic, kinematic, and kinetic forms), and depend on the expression tools used in the creation and simulation of the mutability of forms. Computer animation is not only a tool, but also a way of thinking about the architectural form as an object immersed in space-time, therefore it will influence the way of designing and contribute to the emergence of a new generation of forms in the near future. Time-based architecture of the information age will explore the idea of streaming architecture.

PL

Architektura ery cyfrowej, eksplorująca wymiar czasu, nawiązuje do koncepcji sztuki tzw. time-based art. Współczesne technologie komputerowe pozwalają na symulację zmienności form architektonicznych i ich percepcji w powiązaniu z ruchem obserwatora w przestrzeni oraz tworzenie dynamicznych struktur przestrzennych dzięki zastosowaniu inteligentnych materiałów i technologii w architekturze. Celem badań było określenie wpływu koncepcji czasu na kształtowanie form architektonicznych oraz kierunków rozwoju form architektonicznych wyznaczonych przez technologie odkryte podczas rewolucji przemysłowej i informacyjnej (techniki filmowe, wizualizacje komputerowe, symulacje, animacje). Na podstawie strukturalnej analizy dynamicznych relacji między obserwatorem, obiektem architektonicznym a kontekstem, oraz porównawczej i krytycznej analizy współczesnych trendów wyróżniono różne typy architektury czasu. Typy te są pochodnymi ekspresji czasu w trójwymiarowej przestrzeni oraz założeń związanych ze stopniem zmienności i dynamiki struktur przestrzennych (formy kinestetyczne, kinematyczne i kinetyczne) i zależą od narzędzi ekspresji użytych w tworzeniu i symulacji zmienności form. Animacja komputerowa jest nie tylko narzędziem, ale też sposobem myślenia o formie architektonicznej jako obiekcie zanurzonym w czasoprzestrzeni, dlatego będzie wpływać na sposób projektowania, a także przyczyni się do pojawienia się nowej generacji form w najbliższej przyszłości. Time-based architecture oparta na wymiarze czasu architektura epoki informacji będzie eksplorowała ideę architektury streamingu.

7

Relationship of lumbar-hip kinematics during trunk flexion and sex, body mass index, and self-reported energy expenditure: a cross-sectional analysis

Zawadka Magdalena, Smołka Jakub, Skublewska-Paszkowska Maria, Łukasik Edyta, Zieliński Grzegorz, Gawda Piotr

Acta of Bioengineering and Biomechanics

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2023

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Vol. 25, no. 1

56--64

EN

Physical activity (PA) is a well-known, simple and effective preventive and therapeutic intervention for low back pain (LBP). In spite of the growing interest in active lifestyles and its benefits, more needs to be known about the relationship between energy expenditure, body mass and lumbar-pelvic kinematics during the forward bending movement in a group of young asymptomatic people who met PA guidelines. Young people can be identified as a future risk group of civilisation diseases and lumbar-hip kinematics can be considered as a predictor of LBP occurrence. The aim of this study was to identify the association of gender, self-reported energy expenditure, body mass index, and lumbar-hip kinematics in young people. Methods: Sixty-four students at pre-employment stage participated in the study. They declared moderate-to-high PA and activity-induced energy expenditure (AEE) was self-reported. Kinematic data of the lumbar spine, pelvis and hip were collected during forward bending using a 3D motion ca pture system. Results: Sex was found to be associated with pelvis ( = –0.38 p = 0.002) and lumbar mobility ( = 0.49, p < 0.001) during forward bending and BMI was related only to lumbar mobility ( = –0.41, p = 0.001). Recreation AEE significantly predicted hip flexion mobility ( = 0.38, p = 0.002). Conclusions: This study showed that among a sample of physically active young people, BMI, self-reported AEE and sex can partially predict lumbar-hip kinematics during trunk flexion. Recreational PA can be regarded as improving hip mobility and thus making forward bending more effective and less prone to injury.

8

Kinematic analysis of the basketball jump shot with increasing shooting distance: comparison between experienced and non-experienced players

Caseiro André, Faro Ana, França Cíntia, Branquinho-Gomes Beatriz

Acta of Bioengineering and Biomechanics

|

2023

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Vol. 25, no. 2

61--67

EN

Basketball jump shot success is determined mainly by the height, velocity and angle of ball release. To achieve a successful shot, these variables need to be adjusted according to the player’s position on the court. This study aimed to identify the changes in kinematics variables of the basketball jump shot with an increasing shooting distance performed by players with varying skill levels. Methods: Seventeen male subjects, divided into experienced (N = 9), and non-experienced (N = 8) players, performed three successful jump shots from the free-throw line (4.23 m) and the 3-point line (6.75 m). All attempts were recorded at 120 Hz with a camera perpendicularly to the sagittal plane, and the kinematics variables were calculated using Tracker software. Results: The increase in shooting distance shows a decrease in height and angle of ball release. In contrast, the velocity of ball release increased for both groups at longer distances. Experienced players presented a higher mean value of the height of ball release in both distances, which allowed for a lower velocity of ball release. Conclusions: The most meaningful improvement for players training the jump shot technique is to increase the release height of the ball, jumping higher and shooting the ball near the peak of the jump.

9

Analysis of segmental coordination in the lower extremity using vector coding: a pilot return-to-play study of acute ankle sprain

Yang Xiaoyi, Jiang Hanhui, Yu Peimin, Mei Qichang, Fernandez Justin, Gu Yaodong

Acta of Bioengineering and Biomechanics

|

2023

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Vol. 25, no. 4

23--34

EN

Background: Acute ankle sprain may affect ankle function during sport and daily activities. This study aimed to use vector coding technique to analyze the difference over time between injured and healthy lower limb during the first week of acute ankle sprain phase (P1) and post a 1-month recovery phase (P2) to understand the return-to-play coordination strategy in the lower extremity. Methods: Six females attended the gait experiments with attached 40 reflective markers using eight camera Vicon motion capture system. All participants walked barefoot while turning in four directions (T0°, T45°, T90°, T135°) at their self-selected speed. Coordination patterns were classified as in-phase, anti-phase, proximal or distal dominancy between lower limb joints involving hip, knee, ankle, subtalar, metatarsophalangeal (MTP) joint and tarsometatarsal (TMT) joint. Results: P1 showed more proximal joint dominant in Hip-Knee coupling angles but P2 displayed more distal joint dominant in Knee-Ankle joint coordination pattern and mainly distal joint dominant in Ankle-MTP coupling angle mapping. The Ankle-TMT1 and Ankle-TMT5 coordination patterns matched best in straight walking but worst in T135 walking. Conclusions: Investigating inter-segmental coordination in different turning movements could provide insights into gait changes from acute ankle sprain from one-month return-to-play recovery. Knowledge of lower limb coordination pattern may provide clinical implications to improve dynamic balance and gait stability for individuals with acute ankle sprain.

10

Rejestracja obrazów a kalibracja kinematyki manipulatorów

Orozco Roberto, Ratajczak Adam

Prace Naukowe Politechniki Warszawskiej. Elektronika

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2022

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z. 197, t. 1

21-30

PL

Referat podejmuje próbę zaadaptowania wariacyjnych metod rejestracji obrazów do kalibracji kinematyki robotów manipulacyjnych. Rozpatrzono możliwość wykorzystania dyfeomorficznego dopasowania punktów charakterystycznych (ang. Diffeomorphic Landmark Matching) jako narzędzia do obliczania przekształceń dla szczególnej metody kalibracji, mianowicie kalibracji przez dyfeomorfizmy. Sformułowano problem rejestracji obrazów oraz przedstawiono idee związane z kalibracją prze dyfeomorfizmy. Efektywność takiego podejścia została zweryfikowana badaniami symulacyjnymi dla modelu kinematyki podwójnego wahadła.

EN

The paper addresses an attempt to adapt variational methods of the image registration to the calibration of manipulator kinematics. In particular, it considers an application of Diffeomorphic Landmark Matching as a tool for computing transformations for a specific calibration method, namely the calibration by diffeomorphisms. Image registration formalism as well as the ideas underlying the calibration method has been presented. The results of bonding these two theories have been evaluated by means of simulations.

11

Odporna kinematyka odwrotna w konfiguracjach osobliwych

Dulęba Ignacy

Prace Naukowe Politechniki Warszawskiej. Elektronika

|

2022

|

z. 197, t. 1

5-10

PL

W referacie przedstawiono zasady konstrukcji odpornych algorytmów kinematyki odwrotnej w konfiguracjach osobliwych i ich otoczeniu, uzasadniające także klasyczny algorytm odpornej odwrotności. Zaproponowano sposób addytywny i multiplikatywny wprowadzania poprawki do macierzy źle uwarunkowanej, by przywrócić jej dobre uwarunkowanie.

EN

In this paper additive and multiplicative methods of making inverse kinematics robust at (or around) singular configurations were presented. The methods are provable good and as special case cover also the literature robust inverse kinematics method. A clear advantage of robust methods is their independence on the cornak of singularities and simplicity in implementation.

12

Identyfikacja modelu robota mobilnego z użyciem adaptacyjnego obserwatora ESO

Patelski Radosław, Pazderski Dariusz

Prace Naukowe Politechniki Warszawskiej. Elektronika

|

2022

|

z. 197, t. 1

11-20

PL

W pracy rozważa się problem identyfikacji parametrów modelu dynamiki dwukołowego robota mobilnego z napędem różnicowym. Model dynamiki robota sformułowany został przy założeniu, że prędkości kół robota są mierzalnymi sygnałami wyjściowymi, natomiast prądy silników napędzających robota są sygnałami wejściowymi. W celu identyfikacji nieznanych parametrów robota wykorzystano zaproponowany niedawno adaptacyjny obserwator stanu rozszerzonego (PIESO) sformułowany poprzez połączenie klasycznego obserwatora stanu rozszerzonego (ESO) z gradientowym prawem adaptacji. Skuteczność proponowanego podejścia potwierdzono badaniami symulacyjnymi i eksperymentalnymi.

EN

In this paper a problem of identification of parameters of a two-wheeled mobile robot equipped with differential drive is considered. Model of the robot dynamics is formulated under an assumption that velocities of wheels are measurable outputs of the system, while the motor currents are input signals. In order to identify unknown parameters, a recent adaptive parameter identifying extended state observer (PIESO) algorithm is employed, which combines a classic ESO observer with a gradient adaptation law. The effectiveness of the proposed approach is validated by numerical and experimental trials.

13

Kinematic analysis of L4–L5 spinal segment with spondylolysis and different types of grade 1 spondylolisthesis: a nonlinear finite element study

Yaroub Suhaib, Hamandi Sadiq J., Mohson Khaleel

Acta of Bioengineering and Biomechanics

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2022

|

Vol. 24, no. 2

177--186

EN

This work aimed to evaluate and characterize the motion of the fourth and fifth lumbar vertebrae functional spinal unit with spondylolysis and different types of grade 1 spondylolisthesis using the finite element method. Methods: Nine nonlinear three-dimensional finite element models were reconstructed from computed tomography scans to five educational fourth and fifth lumbar vertebrae models. The intervertebral disc was simulated in two conditions: four models with healthy discs and five models with degenerated discs. Each model consisted of two vertebrae divided into three bony parts, two endplates, an intervertebral disc and five ligaments. The flexion, extension, lateral bending and rotation loading conditions were simulated, and the ranges of motion were measured and plotted. Results: In flexion, compared to the baseline intact model, the most significant increase in the range of motion was experienced by the isthmic spondylolisthesis model, while in extension, a reduction in the range of motion was measured in both prolonged pars and unilateral pars defect and healthy disc models. In degenerated disc results, the unilateral pars defect and degenerative spondylolisthesis models had the lowest range of motion. No large differences were noticed in lateral bending results. Lastly, in axial rotation, the most significant increase in the range of motion was measured in the isthmic spondylolisthesis model, followed by the spondylolysis model and similarly, in the degenerated disc models. Conclusions: The isthmic spondylolisthesis displayed hypermobility in flexion and rotation. Moreover, the model with unilateral pars defect showed hypermobility in axial rotation only. Finally, hypomobility in all movements was noticed with the degenerative spondylolisthesis model.

14

An Innovative Project of a Bionic Robot for Social Applications in Felinotherapy

Litwin Sonia, Woźniak Klaudia, Olszewski Mariusz

Pomiary Automatyka Robotyka

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2021

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R. 25, nr 4

5--18

EN

The paper describes an innovative design of a bionic robot for applications in felinotherapy supporting hospital and home psychotherapeutic treatment of bedridden children and adults. The project was engineered by biomimicrating a biological cat, reaching its robotic model. Particular attention in this process was devoted to capturing the essence of feline motorics behavior and the possibility of mapping them in a mechatronic model. The geometry, kinematics and kinetics of this model were analyzed, creating assumptions for its practical implementation in the real mechanism of cat skeleton movement. The used software used the topology of elements in Autodesk Fusion 360 Simulation workspace by performing the critical elements of the mechatronic model in print using SLS technology. The work was also supported by a graphical simulation in the PyBullet environment.

PL

W pracy opisano innowacyjny projekt bionicznego robokota dla zastosowań w felinoterapii, wspomagającej szpitalne i domowe leczenie psychoterapeutyczne obłożnie chorych dzieci i dorosłych. Projekt zrealizowano inżyniersko przez biomimikrowanie biologicznego kota, dochodząc do jego robotycznego modelu. Szczególną uwagę w tym procesie poświęcono uchwyceniu istoty kocich zachowań ruchowych i możliwości ich odwzorowania w mechatronicznym modelu. Przeprowadzono analizę geometrii, kinematyki i kinetyki tego modelu, tworząc założenia jego praktycznej realizacji w rzeczywistym mechanizmie kociego ruchu. W wykorzystanym oprogramowaniu korzystano z topologii elementów w obszarze roboczym Autodesk Fusion 360 Simulation, wykonując krytyczne elementy mechatronicznego modelu drukiem, w technologii SLS. Prace wspomagano także symulacją graficzną w środowisku PyBullet.

15

Running speed does not influence the asymmetry of kinematic variables of the lower limb joints in novice runners

Jiang Xinyan, Chen Hairong, Sun Dong, Baker Julien S., Gu Yaodong

Acta of Bioengineering and Biomechanics

|

2021

|

Vol. 23, no. 1

69--81

EN

Purpose: The purpose of this study was to evaluate kinematic variables at 5 running speeds (8 to 12 km/h), for the asymmetry between lower limbs. We also investigated the effects of running speed on the bilateral asymmetry of the lower limb joints kinematic variables among novice runners. Methods: Kinematic (200 Hz) running data were collected bilaterally for 17 healthy male novice runners (age: 23.1 ± 1.3 years, height: 1.77 ± 0.04 m, mass: 72.3 ± 4.57 kg, BMI: 23.1 ± 1.0 kg/m2) running on a treadmill at 5 fixed speeds (8, 9, 10, 11 and 12 km/h) in a randomized order. Symmetry angles (SA) were calculated to quantify gait asymmetry magnitude at each running speed. Results: Overall, SPM analysis using paired t-tests revealed significant joints kinematic differences between the left lower limb and the right lower limb at each running speed. Significant differences between limbs were found for all joint kinematic variables in the ankle and hip, regardless of running speed. As for the knee angle, significant differences between legs were only found during the running speed of 11 km/h. For knee angle velocity, significant differences between legs were found in all running speeds except for 8 km/h. However, there was no noticeable difference in asymmetry values across running speeds. Conclusions: The findings of the current study indicate that gait asymmetry of joint kinematics variables between lower limbs during running is apparent in healthy novice runners. Meanwhile, running speed does not influence lower limb joints kinematic asymmetry among novice runners.

16

Lower extremity stiffness in habitual forefoot strikers during running on different overground surfaces

Zeng Ziwei, Yin Lulu, Zhou Wenxiong, Zhang Yy, Jiang Jiayi, Wang Lin

Acta of Bioengineering and Biomechanics

|

2021

|

Vol. 23, no. 2

73--80

EN

Purpose: Sports surface is one of the known external factors affecting running performance and injury. To date, we have found no study that examined the lower extremity stiffness in habitual forefoot strikers running on different overground surfaces. Therefore, the objective of this study was to investigate lower extremity stiffness and relevant kinematic adjustments in habitual forefoot strikers while running on different surfaces. Methods: Thirty-one male habitual forefoot strikers were recruited in this study. Runners were instructed to run at a speed of 3.3 m/s (±5%) on three surfaces, named synthetic rubber, concrete, and artificial grass. Results: No significant differences were found in leg stiffness, vertical stiffness, and joint stiffness in the sagittal plane during running on the three surfaces ( p > 0.05). Running on artificial grass exerted a greater displacement in knee joint angle than running on synthetic rubber ( p = 0.002, 95% CI = 1.52–7.35 degrees) and concrete ( p = 0.006, 95% CI = 1.04–7.25 degrees). In the sagittal plane, peak knee moment was lower on concrete than on artificial grass ( p = 0.003, 95% CI = 0.11–0.58 Nm/kg), whereas peak ankle moment was lower on synthetic rubber than on concrete (p < 0.001, 95% CI = 0.03–0.07 Nm/kg) and on artificial grass (p < 0.001, 95% CI = 0.02–0.06 Nm/kg). Among the three surfaces, the maximal ground reaction forces on concrete were the lowest (p < 0.05). Conclusions: This study indicated that running surfaces cannot influence lower extremity stiffness in habitual forefoot strikers at current running speed. Kinematic adjustments of knee and ankle, as well as ground reaction forces, may contribute to maintaining similar lower extremity stiffness.

17

Kinematics and workspace analysis of a robotic device for performing rehabilitation therapy of upper limb in stroke-affected patients

Valayil Tony Punnoose, Augustine Rose Shaji

Acta of Bioengineering and Biomechanics

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2021

|

Vol. 23, no. 3

175--189

EN

Purpose: Exoskeleton robots generally have multi-functions and one such function is doing rehabilitation therapy in upper limb and lower limb in stroke-affected patients. A novel hybrid (serial-parallel) robot manipulator was proposed in this paper for rehabilitation of upper limb and its kinematics are studied systematically. This robot manipulator intends to perform wrist flexion, wrist extension, wrist radial deviation, wrist ulnar deviation, elbow flexion, elbow extension, elbow pronation and elbow supination motions. The contemporary mechanical designs especially the kinematic structure of upper limb exoskeleton robots have a unique feature that is, almost all of them use serial manipulators, and few others used parallel manipulators. The kinematic structure of the proposed robot is that of a hybrid manipulator (two parallel manipulators connected in series) which has 4-degrees-of-freedom. It is composed of an upper 3SPS-type parallel manipulator and 2SPR-type parallel manipulator connected in series. Methods: The Jacobian and Hessian Matrix method was used to derive the manipulator kinematic formula for solving the displacement, velocity and acceleration. Results: A 3D model of the robotic arm was constructed and analyzed by simulation. The positioning workspace of manipulator was constructed and analyzed. Conclusions: The 3SPS-type parallel manipulator has good kinematic characteristics while performing wrist motions. The 2SPR-type parallel manipulator produced singular configuration, while performing the desired rehabilitation elbow motions, it was found to not be suitable for usage in performing rehabilitation therapy in stroke-affected patients.

18

The effects of ArUco marker velocity and size on motion capture detection and accuracy in the context of human body kinematics analysis

Wieczorek Bartosz, Warguła Łukasz, Kukla Mateusz, Kubacki Arkadiusz, Górecki Jan

Technical Transactions

|

2020

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Vol. 117, iss. 1

art. no. e2020036

EN

The research aim was to analyse the influence of velocity and size of markers on the accuracy of motion capture measurement utilising image processing with the use of OpenCV. On the basis of the obtained results, the usefulness of the applied measurement method in studying the kinematics of the human body while driving operating a wheelchair was determined. This article presents the test results for a low-budget motion capture measurement system for testing the kinematics of the human body in a single plane. The tested measuring system includes a standard activity camera Xiaomi Yi4K, expanded polystyrene markers with printed ArUco codes, and original software for marker position detection developed by the author. The analysis of the measurement method with regard to its applicability in biomechanical studies has highlighted several key factors: the number of measuring points, measurement accuracy expressed as a relative error and the limit velocity at which the marker trajectory is correctly represented. The article shows that the limit velocity of the marker is 2.2 m/s for 50x50 mm markers and 1.4 m/s for 30x30 mm markers. The number of measured points ranged from 233 to 2,457 depending on the marker velocity. The relative error did not exceed 5% for the marker velocities and thus provided a correct representation of its trajectory.

19

Modern Industrial Robotics

Olszewski Mariusz

Pomiary Automatyka Robotyka

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2020

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R. 24, nr 1

5--20

EN

In the past decade, robots have become the basic tools for the automatization and robotization of industrial production, as they used to be in the 70s programmable controllers, in the 80s processor drive controllers, in the 90s of the twentieth century frequency controlled AC motors and in the first years of the 21st century digitization, expressed in the significant advancement and dissemination of computerization, telecommunications and internetization. This role is evidenced by further, beyond conventional robotics, extension of its application and the emergence of new hardware and software solutions oriented towards joint, by robots and human, undertaking of hitherto not rationalized production tasks. This essay is devoted to these transformations in contemporary robotics.

PL

Roboty stały się w mijającym dziesięcioleciu podstawowymi narzędziami automatyzacji i robotyzacji produkcji przemysłowej, tak jak kiedyś, w latach 70. sterowniki programowalne, w latach 80. procesorowe regulatory napędów, w latach 90. XX wieku nastawniki częstotliwościowe silników prądu przemiennego i w pierwszych latach XXI wieku cyfryzacja, wyrażająca się istotnym zaawansowaniem i upowszechnieniem informatyzacji, telekomunikacji i internetyzacji. Świadectwem tej roli jest dalsze, poza obszary konwencjonalnej robotyki, rozszerzanie jej aplikacji i pojawienie się nowych rozwiązań sprzętowych i programowych ukierunkowanych na wspólne, przez roboty i człowieka, podejmowanie dotychczas nie racjonalizowanych zadań produkcyjnych. Tym właśnie przemianom we współczesnej robotyce poświęcony jest ten esej.

20

Path planning optimization and object placement through visual servoing technique for robotics application

Patel Sumitkumar, Israni Dippal, Shah Parth

Journal of Automation Mobile Robotics and Intelligent Systems

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2020

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Vol. 14, No. 1

39--47

EN

Visual servoing define a new methodology for vision based control in robotics. Vision based action involve number of actions that move a robot in response of results of camera analysis. This process is important to operate and help robot to achieve a specific goal. The main purpose of visual servoing consists of considering a vision system by specific sensor dedicated to involve control servo loop and task. In this article, three visual control scheme: Image Based Visual Servoing (IBVS), Position Based Visual Servoing (PBVS) and Hybrid Based Visual Servoing (HBVS) are illustrated. The different terminologies are represented through effective workflow of robot vision. IBVS method concentrate on the image features that are immediately available in the image. This experiment is performed by estimating distance between camera and object. PBVS consist of moving object 3-D parameters to estimate measurement. This paper showcases PBVS using kuka robot model. HBVS uses the 2D and 3D servoing by combining visual sensors also it overcomes challenges of previous two methods. This paper represents HBVS method using IPR communication robot model.