Design Of Robotic Manipulators Research Articles

Design and control of the Six-DOF robotic manipulator

This paper presents the building process and simulation of a robotic manipulator. Robotic manipulators are used in various scenarios, such as industry and agriculture. It would be of particular interest to learn how to systematically design and control a manipulator to follow a planned trajectory. Hence, a CAD model is developed in this paper. There is a rough finite element analysis for two cases in this study, which could easily find out how the product reacts to real-world forces and vibration. In order to solve real-world problems safely and effectively, this effort intends to build the mechanical design of the manipulator by SOLIDWORKS and simulate trajectory tracking capability using MATLAB.

Designing Digital Twins of Robots Using Simscape Multibody

Digital twins of industrial and collaborative robots are widely used to evaluate and predict the behavior of manipulators under different control strategies. However, these digital twins often employ simplified mathematical models that do not fully describe their dynamics. In this paper, we present the design of a high-fidelity digital twin of a six degrees-of-freedom articulated robot using Simscape Multibody, a Matlab toolbox that allows the design of robotic manipulators in a rather intuitive and user-friendly manner. This robot digital twin includes joint friction, transmission gears, and electric actuators dynamics. After assessing the dynamic accuracy of the Simscape model, we used it to test a computed torque control scheme, proving that this model can be reliably used in simulations with different aims, such as validating control schemes, evaluating collaborative functions or minimizing power consumption.

Fast Convergent Ali Baba and Forty Thieves Algorithm for Inverse Kinematic Solution of 7-DOF Robotic Manipulator

Inverse kinematics is a crucial topic in robotics, enabling robots to calculate the joint angles required to achieve the desired end effector position and orientation. Solving the inverse kinematics problem quickly with high accuracy is vital for robot manipulators. If sufficient speed is provided, the real-time motion planning task of robot manipulators can be achieved. Real-time motion planning of complex robot manipulators is not possible with classical mathematical methods. Overcoming this problem will provide many benefits in the design and control of robot manipulators. In contemporary research, metaheuristic approaches have become widely employed for addressing the inverse kinematics problem. This investigation utilizes the efficient and simple Ali Baba and the Forty Thieves (AFT) algorithm to resolve the inverse kinematics problem. To increase convergence speed of AFT, a parameter has been used in early iterations of the algorithm to prevent thieves from randomly searching within the search area to find Ali Baba when they realized they had been deceived. Additionally, an approach has been proposed regarding the accuracy of the information brought by the Marjaneh. Finally, the inverse kinematics solution of the 7-DOF robot manipulator was carried out comparatively.

Generalized algorithm for designing the mechanical part of an industrial robot manipulator

The paper presents a method that allows you to design and calculate the design of an industrial robot manipulator using modern computer systems (CAD, CAE). Due to the versatility, the scope of application of this method can be different from the design of turntables to flexible production complexes. But the main focus of the method is the design of an industrial robot manipulator. The paper presents an example of the design and calculation of an in-dustrial robot manipulator, which will later be manufactured in a single copy.

Nonlinear Functional Observer Design for Robot Manipulators

In this paper, a nonlinear functional observer (NFO) is first proposed for the control design of robot manipulators under model uncertainties, external disturbances, and a lack of joint velocity information. In principle, the proposed NFO can estimate not only lumped disturbances and uncertainties but also unmeasurable joint velocities, which are then fed back into the main controller. Compared to the well-known ESO design, the proposed NFO has a simpler structure, more accurate estimations, and less computational effort, and consequently, it is easier for practical implementation. Moreover, unnecessary observations of joint displacements are avoided when compared to the well-known extended state observer (ESO). Based on the Lyapunov theory, globally uniformly ultimately bounded estimation performance is guaranteed by the proposed NFO. Consequently, it is theoretically proven that the estimation performances of the NFO are better than those of the ESO. Simulations with a two-degree-of-freedom (2-DOF) robot manipulator are conducted to verify the effectiveness of the proposed algorithm in terms of not only the estimation performance but also the closed-loop control performance.

Design, Control, and Experiments of A Novel Robotic Uterine Manipulator with the Motorized 3-DoF Manipulation Rod.

To address the issue of declining performance over time with manual uterine manipulation during minimally invasive gynecologic surgery, we propose a novel uterine manipulation robot that offers tireless, stable, and safer manipulation. This proposed robot consists of a 3-DoF remote center of motion (RCM) mechanism and a 3-DoF manipulation rod. The RCM mechanism uses a single-motor bilinear-guided design that allows for a wide range of pitch motion (-50 to 34 degrees) while maintaining a compact structure. The manipulation rod has a tip diameter of only 6 mm, allowing it to accommodate almost any patient's cervix. The 30-degree distal pitch motion and ± 45-degree distal roll motion of the instrument further improve uterine visualization. The tip of the rod can be opened into a T-shape to minimize damage to the uterus. Laboratory tests have revealed that our device has a highly precise mechanical RCM accuracy of 0.373mm and is capable of handling a maximum load of 500g. Furthermore, through clinical testing, the robot has been proven to offer improved manipulation and visualization of the uterus, making it a valuable addition to the surgical tools available to gynecologists.

Design and Modeling of a Hybrid Soft Robotic Manipulator With Compliant Mechanism

The recent surge of interest in soft robotics has prompted many interesting soft robotic manipulator designs to be proposed. However, current soft robotic manipulators mainly focus on bending and rotation, while elongation has not received attention due to the limited extension/contraction range or the inextensibility of the backbone. This will adversely affect the application of soft robotic manipulators. In this letter, we introduce a hybrid soft robotic manipulator capable of controllable elongation and give a modeling method based on equilibrium principles and assuming a priori deformed configuration. The hybrid soft manipulator consists of a multi-chamber soft body and a rod-driven compliant mechanism, wherein the compliant mechanism provides a push-pull drive to constrain the motion of the manipulator. The model is a modeling framework for a multi-chamber soft robotic manipulator that depicts the relationship between pressures, bending, rotation, and elongation. We experimentally verify the model and demonstrate the potential of the hybrid soft manipulator for point tracking, by comparing it with the soft manipulator without driving rods.

A Novel Variable Stiffness Compliant Robotic Link Based on Discrete Variable Stiffness Units for Safe Human–Robot Interaction

AbstractVariable stiffness manipulators balance the trade-off between manipulation performance needing high stiffness and safe human–robot interaction desiring low stiffness. Variable stiffness links enable this flexible manipulation function during human–robot interaction. In this paper, we propose a novel variable stiffness link based on discrete variable stiffness units (DSUs). A DSU is a parallel guided beam that can adjust stiffness discretely by changing the cross-sectional area properties of the hollow beam segments. The variable stiffness link (Tri-DSU) consists of three tandem DSUs to achieve eight stiffness modes and a stiffness ratio of 31. To optimize the design, stiffness analysis of the DSU and Tri-DSU under various configurations and forces was performed by a derived linear analytical model which applies to small/intermediate deflections. The model is derived using the approach of serially connected beams and superposition combinations. 3D-Printed prototypes were built to verify the feature and performance of the Tri-DSU in comparison with the finite element analysis and analytical model results. It’s demonstrated that our model can accurately predict the stiffnesses of the DSU and Tri-DSU within a certain range of parameters. Impact tests were also conducted to validate the performance of the Tri-DSU. The developed method and analytical model are extendable to multiple DSUs with parameter configurations to achieve modularization and customization, and also provide a tool for the design of reconfigurable collaborative robot (cobot) manipulators.

Design and development of robotic Manipulator’s for medical surgeries

Design and development of robotic Manipulator’s for medical surgeries

Experimental tolerance design of robot manipulators accounting for positioning accuracy reliability

AbstractA new tolerance design method based on experimental design and positioning accuracy reliability is presented to deal with uncertainties of robot manipulators resulting from manufacturing and assembly processes. Initially, the performance function of positioning accuracy is established according to the kinematic model and response surface technique. An analytical algorithm for positioning accuracy reliability calculation is developed based on eigen‐decomposition and saddlepoint approximation methodologies. Inner orthogonal arrays of kinematic parameter tolerances along with the outer uniform arrays of joint variables are then constructed to analyze significant tolerances that affect the positioning accuracy reliability within the entire workspace. Finally, the applicability and performance of the proposed method are verified by case studies of a two‐link planar manipulator and a six‐degree‐of‐freedom robot manipulator. The results confirmed that the proposed method can efficiently and accurately analyze the positioning accuracy reliability, and the method recognizes the impact of kinematic parameters on the motion performance which is able to guide the tolerance range selection of robot manipulators.

Design of robotic manipulator for painting purposes in automotive industry

This paper presents design of 6-DOF robotic manipulator for painting in automotive industry. The NX-CAD was employed as the software to model the robotic manipulator. Three questions were considerably taken into account before modelling the robotic manipulator and they include the following: ‘how to define the problem the design of manipulator is going to solve?’; ‘what is the purpose of the manipulator construction?’ and ‘what were the exact requirements?’, as first , second and third questions respectively. The robotic manipulator analysis showed that the manipulator is more effective in achieving task; it is faster than human efforts and in its interaction with the environment. Through this, it will help reduce health hazard associated with humans that do work of painting by them not having direct contact with the paint (which is produced by chemicals) anymore but engage in handling other paint delivery equipment. Correspondingly, the designed painting manipulator will create cost-effectiveness of labour in automotive industry.

Design of robotic manipulator for painting purposes in automotive industry

Design of robotic manipulator for painting purposes in automotive industry

Soft Gripper with Electro-Thermally Driven Artificial Fingers Made of Tri-layer Polymers and a Dry Adhesive Surface.

Soft grippers have attracted great interest in the soft robotics research field. Due to their lack of deformability and control over compliance, it can be challenging for them to pick up objects that are too large or too small in size. In particular, compliant objects are vulnerable to the large grasping force. Therefore, it is crucial to be able to adjust the stiffness of the gripper materials. In this study, a soft gripper consisting of three artificial fingers is reported on. Each of the artificial fingers is made of a tri-layer polymer structure. An exterior layer, made of an ecoflex-graphene composite is embedded with electric wires as a heating source, by applying direct-current potential. The Joule heat not only allows for deformation of the exterior layer, but also transfers heat to the middle layer of the thermoplastic polyurethane (TPU) elastomer. As a result, the stiffness of the TPU layer can be adjusted using electro-thermal heating. Meanwhile, the third layer consists of a polydimethylsiloxane replica as a supporting layer with a gecko-inspired dry adhesive structure. By applying voltage through electric wires, the artificial fingers can bend and, thus, the soft gripper can hold the objects, with the help of the dry adhesive layer. Finally, objects like a shuttlecock, tennis ball and a glass beaker, can be picked up by the soft gripper. This research may provide an insight for the design and fabrication of soft robotic manipulators.

Structure Design and Solution of Kinematics of Robot Manipulator for 3D Concrete Printing

In relation to automated 3D concrete construction printing, a structure design of a suitable robot manipulator is presented as well as analytical solutions of related kinematics. The proposed structure has a higher number of degrees of freedom which can significantly increase the dexterity of a robot end-effector carrying a printing head. It should perform a continual motion along complicated large-scale printing trajectories. The related robot kinematics is derived by a novel representation of working layers in the complex plane using exponential functions. It leads to an explicit derivation of kinematic equations. The theoretical results are presented by examples of motion trajectories with typical configurations of the proposed structure. Note to Practitioners—This paper deals with a design of suitable robot structures for 3D concrete printing. Such concept is determined for on-site printing of residential houses. This area is developing a lot, but without a systematic design of energy-efficient, space-fitting robotic arms. A suitable structure is proposed, including a kinematic description to determine joint coordinates necessary for robot motion control. To ensure continuous energy-balanced motion during a large-scale printing, the redundant links in the structure are also used. Next research tasks focus on trajectory optimisation in complex print profiles.

Design of Robot Manipulators and Functional Classification of Medical Robots

This paper intended to conduct research based on medical robotics, which fundamentally couple information to enhance the performance of human abilities significantly, in this case, surgical interventions, rehabilitation, or simply helping differently-abled people perform daily tasks. This research work aims to comprehend principal concepts in medical robotic designing, analysis, and real-time control of robotic systems within the context of medical applications. Extensive research on telerobotic systems and their applications in robot-assisted minimally invasive surgery/telesurgery is a major aspect of this research. The core aspects focus on the application, functionality, and theoretical aspects of interactive robotic technologies in medicine. Surgical, physiotherapy, and neuro-rehabilitative robotic systems are significant outlooks of medical robotics. Technological aspects, such as instrumentation, mechanisms, imaging, and simulation, were conducted using MATLAB and Webot software. Simulations using software usage was focused on designing robotic medical models and differentiated using functional classification. Three-dimensional robots with better dexterity and degree of freedom were simulated using Webot software. This research work proposes new approaches of augmented reality aiding medical surgeries whereby three-dimensional visualization of organs is detailed as the future of medical applications. Robotic Kinematics and algorithms are studied in detail when designing these robots on CAD/CAM. Comparative studies based on already implemented medical robots were also conducted. The functionality, drawbacks, ethical issues, and consents of patients are comprehended in detail in this research.

Kinematic Model Pruning: A Design Optimization Technique for Simultaneous Optimization of Topology and Geometry

This paper presents a method of optimizing the design of robotic manipulators using a novel kinematic model pruning technique. The optimization departs from an predefined candidate linkage consisting of a initial topology and geometry. It allows simultaneously optimizing the degree of freedom, the link lengths and other kinematic or dynamic performance criteria, while enabling the manipulator to follow the desired end-effector position and avoid collisions with the environment or itself. Current methods for design optimization rely on dedicated and complex frameworks, and solve the design optimization only as decoupled from each other in separate optimization problems. The proposed method only requires the introduction of a simple function, called a pruning function, as an objective function of an optimization problem. The introduced pruning function transforms a discrete topology optimization problem into a continuous problem that then can be solved simultaneously with other continuous objectives, using readily available optimization schemes. Two applications are presented: the optimization of a manipulator for the inspection of radio frequency cavities and a manipulator for maintenance within the future circular collider (FCC).

Design and simulation of 6-DOF cylindrical robotic manipulator using finite element analysis

One of the several applications of robotic manipulators is aiding Unmanned Ground Vehicles (UGVs) in performing dexterous tasks. They have a variety of applications, from gathering rocks or soil samples to being employed as military UGVs. Robotic manipulators for these applications must be able to withstand high inertial loads that might be incurred during cases such as collisions at high speeds or traversal over rugged terrain. This study provides a 6 Degree of Freedom cylindrical manipulator designed according to the suitable parameters. This demands that the manipulator be structurally sound while minimizing weight to maintain a balanced center of gravity. The manipulator can be divided into the 3-DOF cylindrical arm with a prismatic-revolute-prismatic configuration and a 3- DOF end effector. Hollow tubes and plates with truss patterns are utilized to maximize the stiffness to weight ratio. Materials with a high strength-to-weight ratio such as carbon fiber and aluminum alloy (6061-T6 and 7075-T6) are used. The system has a non-back drivable actuation and can lift up to 5 Kgs while sustaining all the challenging circumstances encountered during extreme traversal. SOLIDWORKS was used to create the CAD model, while ANSYS workbench was used for structural analysis.

Towards a solver-aware systems architecting framework: leveraging experts, specialists and the crowd to design innovative complex systems

AbstractThis article proposes the solver-aware system architecting framework for leveraging the combined strengths of experts, crowds and specialists to design innovative complex systems. Although system architecting theory has extensively explored the relationship between alternative architecture forms and performance under operational uncertainty, limited attention has been paid to differences due towhogenerates the solutions. The recent rise in alternative solving methods, from gig workers to crowdsourcing to novel contracting structures emphasises the need for deeper consideration of the link between architecting and solver-capability in the context of complex system innovation. We investigate these interactions through an abstract problem-solving simulation, representing alternative decompositions and solver archetypes of varying expertise, engaged through contractual structures that match their solving type. We find that the preferred architecture changes depending on which combinations of solvers are assigned. In addition, the best hybrid decomposition-solver combinations simultaneously improve performance and cost, while reducing expert reliance. To operationalise this new solver-aware framework, we induce two heuristics for decomposition-assignment pairs and demonstrate the scale of their value in the simulation. We also apply these two heuristics to reason about an example of a robotic manipulator design problem to demonstrate their relevance in realistic complex system settings.

Design and Control of 6-DOF Robotic Manipulator Driven by Pneumatic Muscles and Motor

Design and Control of 6-DOF Robotic Manipulator Driven by Pneumatic Muscles and Motor

Singularity analysis of a 7-DOF spatial hybrid manipulator for medical surgery

Abstract This paper presents the singularity analysis of a 7-degrees of freedom (DOF) hybrid manipulator consisting of a closed-loop within it. From the past studies, it is well-known that the kinematic singularities play a significant role in the design and control of robotic manipulators. Kinematic singularities pose two-fold effects – first, they can induce the loss of one or more DOF of the manipulator and cause infinite joint rates at that particular joint, and second, they help to determine the trajectory or zone with high mechanical advantage. In current work, a 7-DOF hybrid manipulator is considered which is being developed at Council Of Scientific And Industrial Research–Central Scientific Instruments Organisation (CSIR–CSIO) Chandigarh to assist a surgeon during a medical-surgical task. To emulate the natural motion of a surgeon, the challenging configuration with redundant DOF is utilized. Jacobian has been computed analytically and analyzed at each instantaneous configuration with the evaluation of manipulability. Effect of a closed loop in the hybrid configurations is focused at, and utilizing the contour plots, good and worst working zones are identified in the workspace of the manipulator. The verification and validation of best and worst manipulability points (singularities) are done with the help of genetic algorithms, to determine locally and globally optimal configurations. Finally, on the basis of the singularity analysis, the present work concludes with few guidelines to the surgeon about the best and worst working zones for surgical tasks.