Design Of Manipulator Research Articles

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.

Design and analysis of a novel 3-DOF planar parallel manipulator with two kinematic chains

In this work, to enlarge the workspace, a novel 3-DOF planar parallel manipulator (PPM) with two identical RRR kinematic chains is proposed, and this manipulator has a significant advantage in orienting the moving platform (MP) across a wide range of angles. Resorting to the closed-loop vector approach, the inverse position equation and Jacobian matrix of the novel manipulator are established. Payload performance, dexterity performance, and singularity of the proposed manipulator are analyzed based on the Jacobian matrix. To investigate the distribution characteristics of the constant orientation workspace, orientation workspace, and reachable workspace of the proposed manipulator, a numerical discretization method is employed. Under the same working mode and structural parameters, constant orientation workspace and reachable workspace comparisons between the proposed manipulator and another two traditional PPMs are conducted. Focused on three kinds of performance indices, link lengths optimization of the proposed manipulator is carried out. A 4-DOF pick-and-place equipment is fabricated, and the rotational and translational capabilities are verified based on two examples.

Design of metamaterial-based heat manipulators using isogeometric level-set topology optimization

We exploit level-set topology optimization to find the optimal material distribution for metamaterial-based heat manipulators. The level-set function, geometry, and solution field are parameterized using the Non-Uniform Rational B-Spline (NURBS) basis functions to take advantage of easy control of smoothness and continuity. In addition, NURBS approximations can produce conic geometries exactly and provide higher efficiency for higher-order elements. The values of the level-set function at the control points (called expansion coefficients) are utilized as design variables. For optimization, we use an advanced mathematical programming technique, Sequential Quadratic Programming. Taking into account a large number of design variables and the small number of constraints associated with our optimization problem, the adjoint method is utilized to calculate the required sensitivities with respect to the design variables. The efficiency and robustness of the proposed method are demonstrated by solving three numerical examples. We have also shown that the current method can handle different geometries and types of objective functions. In addition, regularization techniques such as Tikhonov regularization and volume regularization have been explored to reduce unnecessary complexity and increase the manufacturability of optimized topologies.

Structure design and kinematic performance of the deployable translational parallel tape-spring manipulator

AbstractA deployable manipulator has the characteristics of a small installation space and a large workspace, which has great application prospects in small unmanned platforms. Most existing deployable manipulators are designed based on rigid links, whose complexity and mass inevitably increase sharply with increasing numbers of rigid links and joints. Inspired by the remarkable properties of tape springs, this paper proposes novel deployable parallel tape-spring manipulators with low mass, simple mechanics, and a high deployed-to-folded ratio. First, a double C-shaped tape spring is presented to improve the stability of the structure. The combined fixed drive component (CFDC) and combined mobile drive component (CMDC) are designed. Then, novel 2-DOF and 3-DOF deployable translational parallel manipulators are proposed based on the CFDC and CMDC, and their degrees-of-freedom (DOFs), kinematics, and stability are analyzed. The coiled tape spring is regarded as an Archimedean spiral, which can significantly improve the accuracy of kinematic analysis. The correction coefficient of the Euler formula is obtained by comparison with simulation results and experimental results. Furthermore, the stability spaces of the 2-DOF and 3-DOF deployable parallel manipulators are given. Finally, a prototype is fabricated, and experiments are conducted to validate the proposed design and analysis.

Maximizing the Throwing Distance of Robotic Manipulators: An Optimization Approach

Abstract Manipulators are increasingly being called upon to perform a wide range of tasks. This paper explores the maximal distance throwing task for robotic manipulators and shows that this characteristic can be incorporated in the kinematic design process. Indeed, knowing the maximum distance that a manipulator can throw objects is useful in determining the viability of certain throwing tasks it might be called upon to execute. This paper studies three optimization problems: optimizing the release state to maximize the throwing distance, optimizing the kinematic trajectory subject to position, velocity, acceleration, and jerk constraints, and finally optimizing the kinematic design of manipulators to maximize the workspace as well as the throwing distance. Three manipulator architectures are used as case studies for these optimizations: a planar RR, a spatial RRR, and a wrist-partitioned 6R manipulator.

Design and testing of a high precision parallel manipulator with hyperbolic–elliptic flexure hinges

A novel six-degree-of-freedom (6-DOF) parallel manipulator (PM) with a 6-PSS configuration is designed as a piston error compensation mechanism in an optical system. To meet the high-precision adjustment requirement, the prismatic hinges are driven by nanometer resolution piezoelectric motors, and hyperbolic–elliptic (H-E) flexure hinges are used as spherical hinges because of their zero clearance and greater precision transmission capability than traditional rigid hinges. The analysis of the closed-loop vector relationship of the kinematic chain of the leg results in the construction of the kinematic equation, which can satisfy the inverse kinematic solution within a certain precision. The Newton–Raphson method is used for the iteration to solve the forward kinematics. A kinematic simulation was performed to verify the accuracy and effectiveness of the kinematic model using the rigid–flexible coupling finite element method. The workspace of the PM was analyzed using inverse kinematics and kinematics simulation. Two test systems were constructed to test the working performance of the PM. The experimental tests demonstrated that the resolution reached the nanometer level and the travel reached the millimeter level.

The Influence of the Operator’s Perception on the Energy Demand for a Hydraulic Manipulator with a Large Working Area

The efficient operation of hydraulic manipulators with expansive working areas is crucial in various applications such as the construction industry, the rescue service, and the military. These machines are characterized by having more capabilities than humans, and they perform tasks that are not repeated in the same environment. For this reason, they are most often controlled by a human in a teleoperation system. This research investigates the influence of the operator’s perception on the energy demand of such manipulators. Specifically, the research focused on assessing how the intuitive control systems, such as primary–secondary solutions, impact the energy consumption. Understanding the relation between the operator’s perception and the energy demand is essential for optimizing manipulator design and operation. Experimental research was conducted to analyze the velocity and acceleration of the manipulator’s effector, which is controlled by human operators under different movement ranges and size ratios. The obtained test results allow for the assessment of the dynamic loads, velocity, and energy consumption of the movement of a manipulator with a large working area due to the limitations resulting from the operator’s perception.

Impact reduction design and control of quadruple-speed manipulator based on motion curve optimization

Impact reduction design and control of quadruple-speed manipulator based on motion curve optimization

Modeling, design and control of a 4-arm delta parallel manipulator employing type-1 and interval type-2 fuzzy logic-based techniques for precision applications

This paper presents the virtual design of a four-arm Delta parallel robot for potential applications in the food industry, specifically for the automated preparation of fast foods. Kinematic and dynamic models were developed based on the morphology of this type of robot. Cutting-edge and previously unexplored control strategies for these types of manipulators are then designed and implemented based on Fuzzy PD and Fuzzy PID configurations. Several performance indicators, such as the Integral Square Error (ISE), Integral Time Absolute Error (ITAE) and Integral Time Square Error (ITSE), were used to conduct a performance comparison of the control techniques, considering type-1 and interval type-2 fuzzy sets. In all the analyzed scenarios, the fuzzy controllers correspond to the Takagi–Sugeno–Kang model using linear functions of the inputs in the outputs. Among the main contributions of this work is the development of a detailed dynamic model of the robot in Simscape, incorporating realistic aspects that are often overlooked during analytical modeling. To ensure more accurate results, the rejection of external disturbances is thoroughly analyzed in simulations, considering elements such as time delays and control signal saturations. The results demonstrate the veracity of the proposed design for a four-arm Delta robot, both in models and in the Simscape/Simulink implementation. In the trajectory tracking task and external disturbance rejection, the superiority of the Fuzzy PID controller with interval type-2 fuzzy sets over fuzzy controllers with PD structure and over type-1 fuzzy sets is evidenced.

Design and experiment of a variable stiffness soft manipulator for non-destructive grasping

Design and experiment of a variable stiffness soft manipulator for non-destructive grasping

Design and Analysis of an MRI-Compatible Soft Needle Manipulator

Needle manipulation with the guidance of magnetic resonance imaging (MRI) plays a key role in minimally invasive procedures such as biopsy and ablation. However, the confined bore and strong magnetic field of the MR environment pose great challenges in developing a robotic system that fulfills the needle manipulation function. This paper presents the design and analysis of a soft needle manipulator (SoNIM) that can achieve needle manipulation in the MR environment. This pneumatically actuated manipulator consists of two bending actuators and one elongation actuator that are completely made of non-magnetic materials. These soft pneumatic actuators can generate flexible movements while maintaining a compact design, ensuring that the SoNIM is accommodated within the MRI bore. The kinematic modeling and closed-loop control of the SoNIM are investigated to achieve the position control of the needle tip. Experiments showed that the SoNIM was capable of directing the needle tip to reach the targets with a satisfactory accuracy of 2.9 ± 0.98 mm. Furthermore, the functionality and MRI compatibility of the SoNIM were validated in the clinical setting, demonstrating the capability of the SoNIM to perform needle manipulation in the MRI bore with negligible degradation to the image quality. With excellent MRI compatibility, compact design, and flexible movements, the SoNIM provides a promising solution for manipulating surgical needles in MRI-guided minimally invasive surgeries.

Constrained Origami Artificial Muscle-Driven Robotic Manipulator Capable of Coordinating Twisting and Grasping Motions for Object Manipulation.

Grasping and twisting motions are vital when manipulating objects due to their fundamental role in enabling precision, adaptability, and effective interaction. However, few studies in soft robotics exploiting artificial muscles have achieved object manipulation in situ through the coordination of twisting and grasping motions akin to our forearm and hand's capabilities. Especially, when using the same artificial muscle module to achieve these two motions will greatly simplify the manufacturing and control complexity. Here, we introduce identical origami artificial muscle modules (OAMMs) subjected to distinct end constraints into the design of the robotic manipulator, allowing it to achieve independent grasping and twisting motions to achieve effective, precise object manipulation. Applying different end constraints to the identical OAMMs yields distinct motions at their ends, where utilizing a fixed end and a sliding end realizes pure translation, while opting for a fixed end and a rotating end enables pure rotation. The differentially constrained OAMMs then serve as soft actuators for the manipulator's torsional mechanism and grasping mechanism to accomplish independent, controllable twisting and grasping motions. The coordination of twisting and grasping motions finally enables the manipulator to complete various tasks, including installing a light bubble, pouring the water from a lidded bottle into a cup, and sorting and stacking puzzle blocks. Our study pioneers the utilization of OAMMs for precise and versatile object manipulation through the coordination of independent twisting and grasping motions.

A design of pneumatic-driven translational pyramidal manipulator and its actively disturbance rejection tracking control

In this study, we have undertaken the design and implementation of a pneumatic-driven translational pyramidal manipulator (PTPM) with the primary objective of achieving reliable and precise motion control, even under conditions where the PTPM may be exposed to disturbances arising from coupling effects and internal uncertainties. To achieve this purpose, the ALADRC, an adaptive controller that integrates a linear active disturbance rejection controller (LADRC) with a reduced-order linear extended state observer (RLESO) and a radial basis function neural network optimizer (RFNNO), is presented in this paper. This ALADRC has the following advantages in the view of practical applications: (1) it rejects total disturbances and coupling effect, (2) it reduces the order of the extended state observer, (3) it selects observer gains according to system frequencies, and (4) it optimizes controller gains in real time. Two trajectory tracking experiments and three disturbance rejection experiments were conducted to verify the trajectory tracking and disturbance compensation performance of the designed PTPM, respectively. The experimental results indicated that the PTPM controlled using the ALADRC increased the robustness in external disturbance rejection and provided accurate trajectory tracking.

Design, Analysis, and Implementation of a 3-DOF Spherical Parallel Manipulator

Design, Analysis, and Implementation of a 3-DOF Spherical Parallel Manipulator

Design and Compensation Control of Modular Variable Stiffness Continuum Manipulator for Nasal Surgery

Design and Compensation Control of Modular Variable Stiffness Continuum Manipulator for Nasal Surgery

Design, Control, and Motion Planning for a Root-Perching Rotor-Distributed Manipulator

Design, Control, and Motion Planning for a Root-Perching Rotor-Distributed Manipulator

Design and Performance Test of a Flexible Manipulator with Variable Stiffness

Design and Performance Test of a Flexible Manipulator with Variable Stiffness

Waterbomb Origami Mechanism Pneumatic Manipulator Design Based on DH Parameter Method and Symmetric Folding Hypothesis

Waterbomb Origami Mechanism Pneumatic Manipulator Design Based on DH Parameter Method and Symmetric Folding Hypothesis

A Novel Articulated Manipulator Design With Mechanism Doublet

A Novel Articulated Manipulator Design With Mechanism Doublet

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.