Delta Robot Research Articles

Vision-based kinematic analysis of the Delta robot for object catching

SUMMARYThis paper proposes a vision-based kinematic analysis and kinematic parameters identification of the proposed architecture, designed to perform the object catching in the real-time scenario. For performing the inverse kinematics, precise estimation of the link lengths and other parameters needs to be present. Kinematic identification of Delta based upon Model10 implicit model with ten parameters using the iterative least square method is implemented. The loop closure implicit equations have been modelled. In this paper, a vision-based kinematic analysis of the Delta robots to do the catching is discussed. A predefined library of ArUco is used to get a unique solution of the kinematics of the moving platform with respect to the fixed base. The re-projection error while doing the calibration in the vision sensor module is 0.10 pixels. Proposed architecture interfaced with the hardware using the PID controller. Encoders are quadrature and have a resolution of 0.15 degrees embedded in the experimental setup to make the system closed-loop (acting as feedback unit).

Inverse Kinematic Control of a Delta Robot Using Neural Networks in Real-Time

This paper presents an inverse kinematic controller using neural networks for trajectory controlling of a delta robot in real-time. The developed control scheme is purely data-driven and does not require prior knowledge of the delta robot kinematics. Moreover, it can adapt to the changes in the kinematics of the robot. For developing the controller, the kinematic model of the delta robot is estimated by using neural networks. Then, the trained neural networks are configured as a controller in the system. The parameters of the neural networks are updated while the robot follows a path to adaptively compensate for modeling uncertainties and external disturbances of the control system. One of the main contributions of this paper is to show that updating the parameters of neural networks offers a smaller tracking error in inverse kinematic control of a delta robot with consideration of joint backlash. Different simulations and experiments are conducted to verify the proposed controller. The results show that in the presence of external disturbance, the error in trajectory tracking is bounded, and the negative effect of joint backlash in trajectory tracking is reduced. The developed method provides a new approach to the inverse kinematic control of a delta robot.

Vision-based force distribution analysis for object catching

The problem of distribution of force, having the frictional contact between the passive object (manipulating) and active fingers (end-effector) of Delta robots, has been discussed. Computation of force components acting on the object’s points, given the wrench acting on the object and the contact points with respect to the body frame (estimated from the vision sensor) using combined parallel robot architecture, is performed. A pre-calibrated vision sensor was used for the pose estimation of the object. The proposed architecture design is intended to carry heavy payload objects for catching in the real-time scenario.

Gripper Control Design and Simulation for OpenROV Submarine Robot

In this work, a design of a gripper for the underwater OpenROV vehicle is presented. OpenROV is an open-source underwater vehicle design for remote underwater exploration. It can enable systems of underwater internet of things and real-time monitoring. Mechanical aspects of the presented gripper design are discussed including actuation, motion transmission, kinematics and general arrangement, which resembles a delta robot. The Denavit-Hartenberg (DH) notation will be employed to define reference frames on one of the fingers in order to build transformation matrices and the forward kinematics matrix. The results from the forward kinematics are used to define the workspace that can be covered by each finger. The maximum force from the fingertip is estimated using Newton-Euler equations. Finally, the transfer function and the mass moment of inertia of the second link in the finger, that is, the fingertip is calculated for control simulations. A control stability analysis is provided and shows a stable system.

A comparative study between PID and PD-SMC and PD-ASMC control applied on a delta robot

Wydawnictwo SIGMA-NOT wydaje czasopisma fachowe informujące swoich czytelników o najnowszych osiągnięciach naukowych i nowoczesnych rozwiązaniach technicznych w Polsce i na świecie, popularyzuje problemy techniczne oraz poszerza wiedzę i kulturę techniczną.

Dynamics of parallel manipulators with hybrid complex limbs — Modular modeling and parallel computing

Parallel manipulators, also called parallel kinematics machines (PKM), enable robotic solutions for highly dynamic handling and machining applications. The safe and accurate design and control necessitates high-fidelity dynamics models. Such modeling approaches have already been presented for PKM with simple limbs (i.e. each limb is a serial kinematic chain). A systematic modeling approach for PKM with complex limbs (i.e. limbs that possess kinematic loops) was not yet proposed despite the fact that many successful PKM comprise complex limbs.This paper presents a systematic modular approach to the kinematics and dynamics modeling of PKM with complex limbs that are built as serial arrangement of closed loops. The latter are referred to as hybrid limbs, and can be found in almost all PKM with complex limbs, such as the Delta robot. The proposed method generalizes the formulation for PKM with simple limbs by means of local resolution of loop constraints, which is known as constraint embedding in multibody dynamics. The constituent elements of the method are the kinematic and dynamic equations of motions (EOM), and the inverse kinematics solution of the limbs, i.e. the relation of platform motion and the motion of the limbs. While the approach is conceptually independent of the used kinematics and dynamics formulation, a Lie group formulation is employed for deriving the EOM. The frame invariance of the Lie group formulation is used for devising a modular modeling method where the EOM of a representative limb are used to derived the EOM of the limbs of a particular PKM. The PKM topology is exploited in a parallel computation scheme that shall allow for computationally efficient distributed evaluation of the overall EOM of the PKM. Finally, the method is applied to the IRSBot-2 and a 3RR[2RR]R Delta robot, which is presented in detail.

Design and Development of Multipurpose Delta Robot

Abstract: This report represents an designing and simulating ideal pick and place robot which should carry out the operations in minimum time and should also be cost efficient. It is four degrees of freedom parallel configuration used for very high speed pick and place operations. The objectives of this report are designing a Delta robot capable of carrying 1kg payload, achieving a cycle rate of 120 cycles per minute covering a work volume of 400x300x200 mm3. The project involves Kinematic & Dynamic modeling of the robot for the above specifications. The kinematic parameters, involving the lengths of the bicep and forearm, are calculated based on the work volume requirements and the dynamic parameters, involving the motor torque and speed, are calculated based on the maximum acceleration requirements and the inertia of the system. The project further involves the structural analysis of the robot which deals with the proper sizing of the mechanical structure which should be capable of withstanding the high torque and acceleration required for smooth and fast motion. The future work involves integrating the mechanical system with the control system and programming the system for a particular application

Task-space impedance control of a parallel Delta robot using dual quaternions and a neural network

Task-space impedance control of a parallel Delta robot using dual quaternions and a neural network

Wireless Multiplexing Control Based on Magnetic Coupling Resonance and Its Applications in Robot

Abstract Nowadays, more and more researchers are pursuing miniaturized and lightweight structure of robots. However, robots with multiple actuators require large control systems if each actuator needs to be controlled independently. In addition, the cables and circuits for control and power supply are the obstacles in reducing size and weight. In this article, a wireless multiplexing control system based on magnetic coupling resonance (MCR) is proposed. The control system can realize wireless energy transmission and control simultaneously. By decomposing a composite signal, it can control multiple actuators with only one input signal. However, in previous researches, their applications are primary and simple due to the switch control without feedback and the lack of systematic design method for robot application. Thus, based on the discrete form of composite signal, the closed-loop of wireless multiplexing control is presented, which makes this promising method a step closer to the practical application. Besides, based on the theoretical model of load power and transmission efficiency, five parameters to be optimized are extracted in accordance with the actual design requirements. The optimization algorithm for load power is proposed using particle swarm optimization (PSO). As for its applications in robots, a Delta robot with flexible linkage and an untethered multidrive pipe robot for sampling operation are designed to demonstrate the proposed control method. The experiment results of the Delta robot show the reliability and accuracy of the system, while the results of the pipe robot prove its potential use in the untethered robot system.

SELF-LEARNING OF DELTA ROBOT USING INVERSE KINEMATICS AND ARTIFICIAL NEURAL NETWORKS

As known as Parallel-Link Robot, Delta Robot is a kind of Manipulator Robot that consists of three arms mounted in parallel. Delta Robot has a central joint constructed as an end-effector represented as a gripper. An Analysis of Inverse Kinematic (IK) used to convert the end-effector trajectory (X, Y) into rotations of stepper motors (ZA, ZB and ZC). The proposed method used Artificial Neural Networks (ANNs) to simplify the process of IK solver. The IK solver generated the datasets contain motion data of the Delta robot. There are 11 KB Datasets consist of 200 motion data used to be trained. The proposed method was trained in 58.78 seconds in 5000 iterations. Using a learning rate (α) 0.05 and produced the average accuracy was 97.48%, and the average loss was 0.43%. The proposed method was also tested to transfer motion data over Socket.IO with 115.58B in 6.68ms.

МОЖЛИВОСТІ ВИКОРИСТАННЯ ТЕХНОЛОГІЙ 3D-ДРУКУ ПРИ ПРОЕКТУВАННІ ТА ВИРОБНИЦТВІ МЕХАНІЗМУ РЕКУПЕРАЦІЇ ЕНЕРГІЇ З ПНЕВМАТИЧНИМ РУШІЄМ

Purpose. Investigate and propose new possibilities of using 3D-printing technologies in designing and manufacturing mechanism of energy recovery with pneumatic motor. Methodology. We have applied the experimental simulation of pneumatic motor, it’s construction and work. Energy recovery mechanism was simulated and it’s parts was created using 3d technology. Results. The existing technologies of 3D printing, types and structure of 3D printers for design and manufacture of special equipment for the energy recovery mechanism with a pneumatic motor are analyzed and considered in detail. The main materials for printing are considered, as well as carbon-containing materials for FDM printing, their properties and characteristics are considered in detail. The kinematic analysis of the printer mechanism for delta type 3D printing is carried out, the positioning errors for this mechanism type are determined. Measurement of the obtained part and processing of statistical data were carried out. The obtained holes of the part are compared with the given nominal values, and the absolute error for the outer and inner diameters is calculated. Originality. For the first time, the roughness of the delta robot rods was calculated, and the structure stress state under the applied forces action was calculated. Practical value. Having analyzed all the above information on the 3D printing using possibility in the special equipment manufacture and parts of the energy recovery mechanism with a pneumatic motor, it is possible to conclude that the special materials and the latest technologies use can reduce the recuperator weight with the required structural elements strength. The information and results obtained in this study actually correlate with similar researches. In addition, they also have a necessary and sufficient basis in order to conduct research on the use of 3D technology for the manufacture of parts and components. References 16, table 1, figures 14.

Research on intelligent vibration suppression control of high-speed lightweight Delta robot

Lightweight Delta robot is typical high-speed and high-precision industrial parallel robot. However, under high-speed condition, because of the lightweight components, it will inevitably lead to the vibration of Delta robot, which reduces the position accuracy and positioning efficiency. To solve this problem comprehensively, this article considers the process vibration and residual vibration of Delta robot, and the intelligent shaping vibration suppression control system is designed by using trajectory planning method of improved trapezoidal mode, shaping control method, and fast terminal sliding mode controller, and the detailed experimental analysis is carried out. The experimental results show that the proposed intelligent shaping vibration suppression control method can well suppress the process vibration and residual vibration of Delta robot, which can effectively improve the operation stability, work efficiency, and position accuracy of Delta robot.

Application and research of robot sorting system based on LabVIEW

Sorting robot is a kind of artificial intelligence robot which has certain sense ability and can classify items. In the sorting industry, its appearance not only reduces the labor input, but also improves the production efficiency of the sorting industry. In this paper, a production line composed of linear Delta robot and 3-DOF robot is studied. The forward and inverse solutions are calculated by MATLAB and simulated by Solid Works. Through the visual processing function, communication function and axle card driving function of Lab VIEW software, the servo motor rotation is controlled to achieve the purpose of the end moving along the predetermined trajectory, and finally the visual sorting function is realized.

Kinetostatic design and development of a non-fully symmetric parallel Delta robot with one structural simplified kinematic linkage

In this work, the structural design of a structure-simplified parallel Delta robot is presented, by considering the kinetostatics, kinematic dexterity and workspace. An approach to normalize the dimensionally inhomogeneous Cartesian stiffness matrix is introduced, and a stiffness evaluation index is defined by means of the singular value decomposition of homogenized stiffness matrix, which is used in the design optimization in turn. A multi-objective design optimization problem is formulated to provide the optimal solutions of different sets of geometric parameters. A set of parameters is selected to lay out the robot, and the tested specifications show the good performances, although the speed is not so high as the commercial FlexPicker and Quattro. A comparative study is carried out between the proposed and original Delta robots by observing joint dynamics, showing that the modified robot structure can improve the robot dynamics. The presented work turns out that the proposed robot is applicable to the pick-and-place operations without high-precision requirement in most industrial sectors.

A novel partially-decoupled translational parallel manipulator with symbolic kinematics, singularity identification and workspace determination

This paper presents a novel three-degree-of-freedom (3-DOF) translational parallel manipulator (TPM) by using a topological design method of parallel mechanism (PM) based on position and orientation characteristic (POC) equations. The proposed PM is only composed of lower-mobility joints and actuated prismatic joints, together with the investigations on three kinematic issues of importance. The first aspect pertains to geometric modeling of the TPM in connection with its topological characteristics, such as the POC, degree of freedom and coupling degree, from which its symbolic direct kinematic solutions are readily obtained. Moreover, the decoupled properties of input-output motions are directly evaluated without Jacobian analysis. Sequentially, based upon the inverse kinematics, the singular configurations of the TPM are identified, wherein the singular surfaces are visualized by means of a Gröbner based elimination operation. Finally, the workspace of the TPM is evaluated with a geometric approach. This 3-DOF TPM features less joints and links compared with the well-known Delta robot, which reduces the structural complexity. Its symbolic direct kinematics and partially-decoupled property will ease path planning and dynamic analysis. The TPM can be used for manufacturing large work pieces.

Machine vision-based relative-angle measurement system between circular holes

In this study, the machine-vision technique is employed to measure the angle between two circular holes for the derailleur parts of a bicycle. A delta robot equipped with a motorized zoom lens is constructed as an automatic measurement device. In this way, we can detect the normal vectors of circular holes with different positions and sizes by using only one camera. By calculating the plane normal vectors of two circular holes within the camera coordinate system and performing the cross-product operation, the angle between the two circular holes is obtained. Simulation experiments reveal that the measurement method is influenced by the projection eccentricity error, and the error can be reduced by increasing the focal length and employing the virtual-center alignment method. The results show that the average error for measuring the derailleur parts is approximately 0.061°, and the standard deviation is 0.112°. Experimental analysis indicates that while the magnification of the image is larger, the average error of the measurement result is reduced, and the standard deviation is reduced as well. When the magnification is 0.4×, the measurement average error is 0.04°, and standard deviation is 0.101°. When the distance between the center of the circle and the center of the image is increased, the error in the angle calculation is also increased. A significant improvement is obtained by setting the fitting center position to the optical central position, which omits the influence of the error amplification caused by the distance of the circular hole from the optical axis.

PARALLEL MANIPULATOR MECHANISM FOR USE IN ROBOTIC SURGERY

The article examines the mechanisms of parallel and parallel-sequential structure, including specific translational-guides, flat, spherical mechanisms of a parallel structure with three degrees of freedom, modifications of Delta robots from various manufacturers. The most famous studies of robots of parallel-serial structure are presented. Mazor Renaissance and Mazor X robotic systems for robotic assistance during spinal surgery are examined. The method of synthesis of mechanisms of parallel-serial structure with five degrees of freedom is briefly presented. Examples of synthesised schemes of mechanisms and three-dimensional schemes, synthesised using in the computer-aided design system Compass 3D, are given. A diagram of a mechanism of a parallel-sequential structure with five degrees of freedom for robotic assistance during minimally invasive operations, which can be used as an alternative to the da Vinci Surgical System Platform, is examined. An example of modelling the solution of the inverse problem of positions, direct and inverse problems of velocities and direct and inverse dynamic problems in the Mathcad system, the result of modelling the motion of the output link in various initial conditions is given. The results of experimental studies using a prototype mechanism are shown.

Development of a control architecture for a parallel three-axis robotic arm mechanism using CANopen communication protocol

Based upon the CANopen communication protocol and the LabVIEW graphic programing procedures, this paper develops a closed-loop control architecture for a parallel three-axis (Delta) robotic arm mechanism. The accomplishments include prototyping a parallel three-axis robotic arm mechanism, assembling servomotors with associated encoders and gearsets, coding CANopen communication scripts for servomotor controllers and a host supervision GUI, coding forward/inverse kinematics scripts to compute the required servomotor rotations and the coordinates of a movable platform or the mechanism, coding tracking error compensation scripts for effective closed-loop griper control, and coding integration scripts to command and supervise the mechanism motion on the LabVIEW-based host GUI. During the development stage, this research designed and prototyped the parallel three-axis robotic arm mechanism based upon basic Delta robot kinematics. To control the mechanism effectively and accurately, this study implemented the CANopen communication protocol, which characterizes high speed and stable transmission. The protocol applies to the CANopen communication channels among the controllers and the host supervision GUI. On the LabVIEW development platform, the coded supervision GUI performs issuing/receiving messages to the CANopen-based controllers. The controllers excite the servomotors and actuate the parallel mechanism to track prescribed trajectories in a closed-loop control fashion. Meanwhile, an electromagnet attached to the movable platform of the robotic mechanism performs satisfactory picking/placing object actions.

Research on Control System of Delta Robot Based on Visual Tracking Technology

Delta parallel robot has the advantages of fast motion speed, accurate positioning, low cost and high efficiency. In this paper, OMRON Adapt Hornet 565 3 axis parallel robot is taken as the research object and the control system of Delta robot based on visual tracking technology is studied. The control flow such as camera configuration, model configuration, and process configuration is described in detail, the control system was tested finally. Through the tests, The parallel robot can grasp different shapes of models accurately and quickly under the action of visual tracking.

A New Chaotic Mixer Design Based on the Delta Robot and Its Experimental Studies

In this study, a new chaotic mixer based on the Delta robot was designed and produced which had been controlled with Arduino Uno card and MATLAB. First of all, chaotic mixing systems with different dynamic properties were chosen for the chaotic mixing process. Then, by solving the chaotic systems selected in the MATLAB with the Runge Kutta 45 (RK45) numerical solution algorithm, the results in the integer format were obtained. The obtained chaotic time-series results were transformed into 3-dimensional position information for the servomotors used in the mixer with the algorithm developed in MATLAB. The supervision was provided to ensure that the newly designed chaotic mixer was pacing chaotically in x, y, and z coordinates by transferring the chaotic position information to the Arduino Uno R3 card via USB 2.0. With the software developed in MATLAB, the performances of 7 diversified chaotic systems’ trajectories and circular motion trajectories were compared over the numerical simulation orbital distribution ratio (ODR). In the final stage, in a solid-liquid mixture type, at the selected constant mixing time, experimental studies were performed where homogeneity and orbital distribution ratio (ODR) parameters were compared by using 7 diversified chaotic systems. The designed and produced chaotic mixer can also be used in experimental studies of certain liquid-liquid mixture types. It is thought that this prototype presented in the article will serve the aim of developing new chaotic mixer systems and algorithms to derive more homogeneous mixtures in a shorter time.