Effect of infill pattern on the mechanical properties of PLA and ABS specimens prepared by FDM 3D printing Shishir Patel, Sneha Gupta, Harshit Saket, Kamesh Bakna, Shiv Singh Patel, Surender Kumar, Veeravalli Ramakoteswara Rao, Ravi Kumar Mandava Proceedings of the Institution of Mechanical Engineers Part E Journal of Process Mechanical Engineering, 2026 Fused deposition modelling (FDM) is a three-dimensional printing technique which has become more popular and spreading in many fields. In this process, the molten thermoplastic is deposited layer by layer using a heated nozzle. Users can set the infill pattern to save the material and printing time. The main objective of this study is to investigate the tensile properties of polylactic acid (PLA) and Acrylonitrile butadiene styrene (ABS) tensile specimens with different infill patterns such as lines, tri-hexagonal and lightning. Further, the test specimens were prepared as per ASTM D638 using Ender 3D printer with varying infill patterns. The specimens were subjected to tensile tests in a mechanical tensile testing machine. It was observed that the specimens with linear infill patterns obtained higher tensile strength than the tri-hexagonal and lightning pattern infilled specimens. Later on, a microstructural study was examined on the fractured surface using scanning-electron-microscopy (SEM). It shows that the line pattern specimens have more uniform structure when compared to hexagonal and lightning pattern specimens.
Development of smooth, asynchronous optimal trajectories for robotic manipulators performing assembly tasks Srinivasulu Vardhineni, Murali Krishna Chimata, Ravikumar Mandava Industrial Robot, 2026 Purpose The purpose of this study is to propose a trajectory generation method for 6 degrees of freedom manipulators that simultaneously optimizes all joint motions for point to point and multipoint tasks. Conventional methods treat each joint independently and synchronize to the slowest, often leading to suboptimal execution time and motion smoothness. The goal is to improve time efficiency and dynamic performance in industrial robotics by leveraging joint-level kinematic constraints. Design/methodology/approach A nonlinear optimization problem is formulated using quintic B-spline interpolation to generate smooth joint trajectories under velocity, acceleration and jerk limits. Segment durations for all joints are optimized simultaneously. The interior-point method is used to solve the problem. The approach is validated through simulation and physical execution on the Dobot Nova5 manipulator using benchmark point-to-point and multipoint motion tasks. Findings The proposed method yields trajectories up to 39% faster than conventional methods in point-to-point tasks. It produces smoother motions with lower peak and average jerk values, improving execution quality. In multipoint scenarios, the method reduces execution time by 3.26% compared to the synchronous B-spline method. Both simulation and experimental results confirm the method’s effectiveness and accuracy. Comparative analysis with recent trajectory planning methods further demonstrates the proposed method’s superior C2 continuity and smooth motion characteristics. Research limitations/implications The proposed trajectory optimization method considers only kinematic constraints, excluding dynamic factors such as torque limits, payload effects and actuator saturation. The framework assumes offline planning under fixed task conditions, limiting adaptability in dynamic environments. Obstacle avoidance is handled via predefined waypoints rather than integrated constraints. Although quintic B-splines offer a balance between smoothness and computational efficiency, alternative spline orders may improve performance in specific contexts. Future work will address dynamic modeling, real-time replanning and integration with collision-aware path planning to enhance practical applicability. Practical implications The proposed method enables smooth, time-optimal trajectory generation for robotic manipulators without synchronizing all joints to the slowest one, improving motion efficiency and productivity. Its asynchronous formulation allows better utilization of joint capabilities under kinematic constraints. By supporting both point-to-point and multipoint tasks, the approach is applicable to a wide range of industrial assembly operations. The method has been validated through hardware experiments, demonstrating consistent execution and repeatability. It can be readily integrated with existing robot controllers and extended with via point-based obstacle avoidance for constrained environments. Social implications The proposed trajectory planning method enhances the operational efficiency of robotic manipulators, contributing to increased automation in manufacturing and assembly tasks. By enabling smoother, faster and more reliable robot motion, it supports safer and more collaborative work environments, especially in human−robot shared workspaces. Improved efficiency and accuracy in industrial processes may reduce energy consumption, material waste and production costs. This advancement supports broader goals of sustainable automation and makes advanced robotics more accessible for small and medium enterprises, potentially impacting workforce roles and productivity in evolving industrial landscapes. Originality/value Unlike traditional decoupled methods, this unified framework globally optimizes all joint motions using quintic B-splines under kinematic constraints. The method is adaptable across robotic platforms and suitable for computer numerical control feedrate planning. It enables smooth and time-efficient trajectories for advanced industrial applications.
Thermal simulation and bead geometry prediction in wire arc additive manufacturing of Inconel 617 VVD Praveen Kalepu, Kattubadi Abubakar Siddiq, Ravi Kumar Mandava Proceedings of the Institution of Mechanical Engineers Part E Journal of Process Mechanical Engineering, 2026 Wire arc additive manufacturing (WAAM) has emerged as a promising technology for fabricating large-scale metal parts, offering high deposition rates, low material waste and compatibility with traditional welding systems. However, the geometric accuracy and structural integrity of WAAM materials remain highly sensitive to steep thermal gradients, particularly in dissimilar material systems, where asymmetric heat flow strongly influences melt pool behaviour. In this work, a three-dimensional, time-resolved thermal finite-element simulation involving WAAM single-layer deposition of Inconel 617 on a mild steel substrate was performed using COMSOL Multiphysics. The arc-based energy input is modelled using a Goldak double ellipsoid heat source, while temperature-dependent thermal properties and latent heat effects are included to realistically simulate melt pool behaviour. A dual-isothermal surface-based bead geometry extraction methodology is employed, using the melting range of Inconel 617 (1605–1653 K) to define bead width (BW) and bead height (BH) and the melting range of mild steel (1723–1793 K) to define penetration depth. This approach enables physically consistent identification of fully molten and thermally softened regions in a dissimilar material context, without reliance on empirical geometric assumptions. In 27 simulated cases, the BW ranged from 3.86 to 6.54 mm, BH from 2.23 to 3.86 mm and bead depth (BD) from 0.34 to 1.08 mm. The bead parameters exhibited a pronounced dependence on wire feed rate and torch travel speed, whereas the torch angle exhibited a comparatively secondary influence. Experimental measurements were used to calibrate and validate the numerical framework, demonstrating good agreement in bead geometry trends and approximate dimensions within the investigated parameter space. The model provides a calibrated thermal simulation tool suitable for parametric studies and process window analysis in WAAM of Inconel 617.
A Novel Review on Quadruped Robots Design Variants, Gait Modulation, and Motion Planning Schemes S. A. Azeez, Ravi Kumar Mandava, Nenavath Srinivas Naik Journal of Field Robotics, 2025 Quadruped robots are gaining more importance among researchers due to their adaptability to complex terrains, though their stability handling is complex. Quadruped robots are one of the best kinds of legged robotic systems with regard to their framework and movement flexibility. For making quadrupeds fully autonomous, it is important to concentrate on their modeling, modulation, and maneuverability. This article sheds light on quadruped robots, starting from the early‐stage developments of TITAN series quadrupeds to current progress based on variations of design, gait analysis, control, and motion planning, so as to provide directions for future researchers to develop efficient quadrupeds. Furthermore, we have made a comparative analysis on various aspects, including various mobile robots, material specifications, leg structure and topology, crucial modeling parameters, sensors and actuation systems, as well as traditional and advanced algorithms. This work explores gait analysis, followed by numerous researchers concentrating on various gait stability challenges; in addition, it presents the studies on control strategies of quadruped robots based on a PID controller, neural network controller, fuzzy logic controller, delayed feedback controller, hybrid controller, and other peculiar controllers. Furthermore, the representative explorations on motion planning algorithms of quadruped robots have been done. To conclude, this paper provides an overview of the various variants of quadrupeds, focusing on important aspects, followed by an analysis of pivot features and providing solutions to current challenges and issues so as to help future researchers in the field identify key areas of research.
Optimizing PID control for enhanced stability of a 16-DOF biped robot during ditch crossing Moh Shahid Khan, Ravi Kumar Mandava, Vijay Panchore Journal of Field Robotics, 2025 The current research article discusses the design of a proportional–integral–derivative (PID) controller to obtain the optimal gait planning algorithm for a 16‐degrees‐of‐freedom biped robot while crossing the ditch. The gait planning algorithm integrates an initial posture, position, and desired trajectories of the robot's wrist, hip, and foot. A cubic polynomial trajectory is assigned for wrist, hip, and foot trajectories to generate the motion. The foot and wrist joint angles of the biped robot along the polynomial trajectory are obtained by using the inverse kinematics approach. Moreover, the dynamic balance margin was estimated by using the concept of the zero‐moment point. To enhance the smooth motion of the gait planner and reduce the error between two consecutive joint angles, the authors designed a PID controller for each joint of the biped robot. To design a PID controller, the dynamics of the biped robot are essential, and it was obtained using the Lagrange–Euler formulation. The gains, that is, KP, KD, and KI of the PID controller are tuned with nontraditional optimization algorithms, such as particle swarm optimization (PSO), differential evolution (DE), and compared with modified chaotic invasive weed optimization (MCIWO) algorithms. The result indicates that the MCIWO‐PID controller generates more dynamically balanced gaits when compared with the DE and PSO‐PID controllers.
Portable coconut tree climbing device and its analysis Ravi Kumar Mandava International Journal of Industrial and Systems Engineering, 2025 The coconut tree is one of the useful plants among all other plants. Due to the lack of coconut tree climbers worldwide, many coconut palm growers are not interested in cultivating coconut farming. Based on the above problem, numerous researchers have developed various climbing mechanisms. To overcome this problem, a novel coconut tree climbing device (CTCD) was introduced which can climb the coconut tree up to the canopy. To check the deformation behaviour and generated stresses of various parts of the device in the present research work, the authors conducted dynamic analysis, such as modal, harmonic, and transient analysis in ANSYS 2021. Moreover, the dynamic properties of each component will also be tested under vibrational excitation. Therefore, one of the vibrational properties, that is, the natural frequency, is used to analyse the effect of transient loads and avoid the noise and vibration hazards in the components of the coconut tree climbing mechanism.
Modelling and structural analysis of coconut tree climbing mechanism Pradip Solanki, Ravi Kumar Mandava International Journal of Engineering Systems Modelling and Simulation, 2025 Due to the shortage of professional climbers for cutting the coconuts, many farmers are looking for coconut tree climbing mechanisms.This article aims to develop the mechanism model and examine the various types of stresses, that is, Von-misses stress and maximum shear stress, and deformation of the various mechanical components of the climbing mechanism.The mechanical parts are required to run the mechanisms are modelled individually in CREO.Further, the analysis has been conducted using ANSYS 2021.The result shows that the stresses acting on each mechanism components are less than the permissible limit of the estimated loading conditions.Therefore, it can be observed that the designed components of the mechanism can effectively withstand the load during operating conditions.
Design of dynamically balanced gait for the biped robot while crossing the obstacle Moh Shahid Khan, Ravi Kumar Mandava Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science, 2024 The primary objective of this research work is to generate a dynamically balanced gait for the 16-DOF biped robot while crossing an obstacle using the concept of the zero moment point (ZMP). Also, the authors discussed both the theoretical justification and its practical feasibility on real biped robot. Initially, the position and orientation of the biped robot were obtained with the help of forward kinematics while crossing the obstacle. Later on, various joint angles of the biped robot were calculated using the inverse kinematics approach. Further, the Lagrange-Euler formulation approach was employed for evaluating the dynamics of the biped robot. To generate the smooth gait of the biped robot, a cubic polynomial equation has been assigned for foot and wrist trajectories in the sagittal plane and hip trajectories in the horizontal plane. This integration allows the robot to cross the obstacles while maintaining dynamic balance, marking a significant advancement while crossing the obstacle with a height and width equal to 50 mm, which is 16.10% of the length of the robot’s leg. While crossing the obstacle, the gait of the biped robot has been considered in three stages, such as landing the foot on the obstacle, landing the foot on the ground away from the obstacle by one leg and crossing over the obstacle by another leg. A simulation study has been conducted on MATLAB to verify the dynamically balanced gait while crossing the obstacle. Finally, the generated gait angles are fed into the real 16-DOF biped robot developed by the Robotics Lab at MANIT Bhopal. It has been observed that the generated gait at three stages is more dynamically balanced while crossing the obstacle.
Human–machine interaction and implementation on the upper extremities of a humanoid robot Panchanand Jha, G. Praveen Kumar Yadav, Din Bandhu, Nuthalapati Hemalatha, Ravi Kumar Mandava, Mehmet Şükrü Adin, Kuldeep K. Saxena, Mahaboob Patel Discover Applied Sciences, 2024 Estimation and tracking the various joints of the human body in a dynamic environment plays a crucial role and it is a challenging task. Based on human–machine interaction, in the current research work the authors attempted to explore the real-time positioning of a humanoid arm using a human pose estimation framework. Kinect depth sensor and media pipe framework are used to obtain the three-dimensional position information of human skeleton joints. Further, the obtained joint coordinates are used to calculate the joint angles using the inverse kinematics approach. These joint angles are helpful in controlling the movement of the neck, shoulder, and elbow of a humanoid robot by using Python-Arduino serial communication. Finally, a comparison study was conducted between the Kinect, MediaPipe, and real-time robots while obtaining the joint angles. It has been found that the obtained result from the MediaPipe framework yields a minimum standard error compared to Kinect-based joint angles.
Effect of infill pattern on the mechanical properties of PLA and ABS specimens prepared by FDM 3D printing S Patel, S Gupta, H Saket, K Bakna, SS Patel, S Kumar, ... Proceedings of the Institution of Mechanical Engineers, Part E: Journal of … , 2026 2026 Citations: 10
Development of smooth, asynchronous optimal trajectories for robotic manipulators performing assembly tasks S Vardhineni, MK Chimata, R Mandava Industrial Robot: the international journal of robotics research and … , 2026 2026 Citations: 3
Thermal simulation and bead geometry prediction in wire arc additive manufacturing of Inconel 617 RKM VVD Praveen Kalepu, Kattubadi Abubakar Siddiq Proceedings of the Institution of Mechanical Engineers, Part E: Journal of … , 2026 2026
A Novel Review on Quadruped Robots Design Variants, Gait Modulation, and Motion Planning Schemes SA Azeez, RK Mandava, NS Naik Journal of Field Robotics 42 (7), 3615-3693 , 2025 2025 Citations: 6
Optimizing PID control for enhanced stability of a 16‐DOF biped robot during ditch crossing MS Khan, RK Mandava, V Panchore Journal of Field Robotics 42 (2), 559-583 , 2025 2025 Citations: 3
Portable coconut tree climbing device and its analysis RK Mandava International Journal of Industrial and Systems Engineering 50 (2), 191-210 , 2025 2025
Modelling and structural analysis of coconut tree climbing mechanism P Solanki, RK Mandava International Journal of Engineering Systems Modelling and Simulation 16 (1 … , 2025 2025
Design of dynamically balanced gait for the biped robot while crossing the obstacle MS Khan, RK Mandava Proceedings of the Institution of Mechanical Engineers, Part C: Journal of … , 2024 2024 Citations: 4
Analysis of Deep Drawing Quality Steel Using Incremental Hole Flanging with Different Pre-Cut Hole Diameters GP Kumar, D Bandhu, RK Mandava, BK Potnuru, SA Azeez Analysis and Optimization of Sheet Metal Forming Processes, 95-127 , 2024 2024 Citations: 1
Human–machine interaction and implementation on the upper extremities of a humanoid robot P Jha, GPK Yadav, D Bandhu, N Hemalatha, RK Mandava, MŞ Adin, ... Discover Applied Sciences 6 (4), 152 , 2024 2024 Citations: 44
Discover Applied Sciences P Jha, GPK Yadav, D Bandhu, N Hemalatha, RK Mandava, MŞ Adin, ... Discover 6, 152 , 2024 2024
Identifying the maturity level of coconuts using deep learning algorithms RK Mandava, H Mittal, N Hemalatha Materials Today: Proceedings 103, 410-414 , 2024 2024 Citations: 10
A review on gait generation of the biped robot on various terrains MS Khan, RK Mandava Robotica 41 (6), 1888-1930 , 2023 2023 Citations: 40
DUS Characterization and Evaluation of Untapped French Bean (Phaseolus vulgaris L.) Genotypes K Pramanik, GS Sahu, GC Acharya, P Tripathy, M Dash, M Kumar, ... Int. J. Environ. Clim. Change 13 (1), 225-243 , 2023 2023 Citations: 1
Design of dynamically balanced gait for the biped robot while crossing the ditch MS Khan, RK Mandava Acta Polytechnica Hungarica 20 (7), 269-288 , 2023 2023 Citations: 4
Design of PID FLC and Sliding Mode Controller for 2-DOF Robotic Manipulator: A Comparative Study M Tomar, S Mandava, N Hemalatha, VR Rao, RK Mandava International Journal of Mathematical, Engineering and Management Sciences 8 … , 2023 2023 Citations: 3
Tribological behaviour of Al6061/Gr/WC hybrid MMCs using multi-response optimisation GR Ponugoti, RK Mandava, PR Vundavilli International Journal of Mathematical Modelling and Numerical Optimisation … , 2023 2023 Citations: 3
Design and development of robotic manipulator’s for medical surgeries D Rao, S Vardhineni, N Hemalatha, S Mandava, RK Mandava Materials Today: Proceedings 80, 195-201 , 2023 2023 Citations: 7
Estimation of dynamic balancing margin of the 10-Dof biped robot by using polynomial trajectories MS Khan, RK Mandava International Conference on Machine Learning, Image Processing, Network … , 2022 2022 Citations: 1
MOST CITED SCHOLAR PUBLICATIONS
Dry sliding wear behavior of Al 6082 metal matrix composites reinforced with red mud particles P Samal, RK Mandava, PR Vundavilli SN Applied Sciences 2 (2), 313 , 2020 2020 Citations: 76
An optimized path planning for the mobile robot using potential field method and PSO algorithm RK Mandava, S Bondada, PR Vundavilli Soft Computing for Problem Solving: SocProS 2017, Volume 2, 139-150 , 2018 2018 Citations: 55
Human–machine interaction and implementation on the upper extremities of a humanoid robot P Jha, GPK Yadav, D Bandhu, N Hemalatha, RK Mandava, MŞ Adin, ... Discover Applied Sciences 6 (4), 152 , 2024 2024 Citations: 44
A review on gait generation of the biped robot on various terrains MS Khan, RK Mandava Robotica 41 (6), 1888-1930 , 2023 2023 Citations: 40
An adaptive PID control algorithm for the two-legged robot walking on a slope RK Mandava, PR Vundavilli Neural computing and Applications 32 (8), 3407-3421 , 2020 2020 Citations: 37
Wear and frictional behaviour of Al 7075/FA/SiC hybrid MMC’s using response surface methodology RK Mandava, VV Reddy, VRK Rao, KS Reddy Silicon 14 (10), 5319-5331 , 2022 2022 Citations: 36
Development of path planning algorithm for biped robot using combined multi-point RRT and visibility graph S Pradhan, RK Mandava, PR Vundavilli International Journal of Information Technology 13 (4), 1513-1519 , 2021 2021 Citations: 33
An efficient path planning algorithm for biped robot using fast marching method K Mrudul, RK Mandava, PR Vundavilli Procedia computer science 133, 116-123 , 2018 2018 Citations: 29
Design of PID Controllers for 4-DOF Planar and Spatial Manipulators RK Mandava, PR Vundavalli RACE-2015 , 2015 2015 Citations: 29
An optimal PID controller for a biped robot walking on flat terrain using MCIWO algorithms RK Mandava, PR Vundavilli Evolutionary Intelligence 12 (1), 33-48 , 2019 2019 Citations: 28
Whole body motion generation of 18-DOF biped robot on flat surface during SSP & DSP RK Mandava, PR Vundavilli International Journal of Modelling, Identification and Control 29 (3), 266-277 , 2018 2018 Citations: 27
Optimization of dry sliding wear parameters of Al 7075 MMC’s using Taguchi method VV Reddy, RK Mandava, VR Rao, S Mandava Materials Today: Proceedings 62, 6684-6688 , 2022 2022 Citations: 23
Near optimal PID controllers for the biped robot while walking on uneven terrains RK Mandava, PR Vundavilli International Journal of Automation and Computing 15 (6), 689-706 , 2018 2018 Citations: 22
Implementation of modified chaotic invasive weed optimization algorithm for optimizing the PID controller of the biped robot RK Mandava, PR Vundavilli Sādhanā 43 (5), 66 , 2018 2018 Citations: 22
Dynamic motion planning algorithm for a biped robot using fast marching method hybridized with regression search RK Mandava, K Mrudul, PR Vundavilli Acta Polytech. Hung 16, 189-208 , 2019 2019 Citations: 21
Forward and Inverse Kinematic based Full Body Gait Generation of Biped Robot PRV Ravi Kumar Mandava International Conference on Electrical, Electronics, and Optimization … , 2016 2016 Citations: 17
Effect of red mud on mechanical and microstructural characteristics of aluminum matrix composites P Samal, R Raj, RK Mandava, PR Vundavilli Advances in Materials and Manufacturing Engineering: Proceedings of ICAMME … , 2020 2020 Citations: 16
Tuning of PID controller parameters of a Biped Robot using IWO algorithm RK Mandava, PR Vundavilli Proceedings of the 2018 4th International Conference on Mechatronics and … , 2018 2018 Citations: 11
Effect of infill pattern on the mechanical properties of PLA and ABS specimens prepared by FDM 3D printing S Patel, S Gupta, H Saket, K Bakna, SS Patel, S Kumar, ... Proceedings of the Institution of Mechanical Engineers, Part E: Journal of … , 2026 2026 Citations: 10
Identifying the maturity level of coconuts using deep learning algorithms RK Mandava, H Mittal, N Hemalatha Materials Today: Proceedings 103, 410-414 , 2024 2024 Citations: 10