Search

Nowadays, various Delta-type robots are widely used in many technological fields. In this work, we propose a novel 5-DOF Delta-type parallel robot with four linear and one rotational actuators. The major part of the article is devoted to the kinematic analysis of the robot, including solving its inverse and forward kinematic problems. To demonstrate the developed techniques, we consider two numerical examples. In the first one, we solve the inverse kinematics and determine the actuator displacements required to realize a spatial trajectory of the output link. The forward kinematic analysis, presented in the second example, results in six different assembly modes of the robot for the given set of the actuator displacements. The proposed algorithms represent the basis for subsequent velocity, acceleration, and dynamic analysis of the robot, and they can be adapted to other Delta-type parallel robots. [ABSTRACT FROM AUTHOR]

The delta robot is considered one of the most well-known representatives of manipulation devices with a parallel structure. It includes three kinematic chains, each containing a rotary drive and a hinged parallelogram. We present solutions to the kinematics problems, including the position problems and the precision analysis problems. When solving them, we applied the screw calculus and showed that contiguity to singular positions causes a repeatability deterioration. [ABSTRACT FROM AUTHOR]

In this study, Delta robot that one of the most studied and used robot and has distinctive advantages and parallel structure, has been optimized in point of dimensions. 3D solid model of the optimized robot model transferred to MATLAB/Simulink environment. Dimensions of the Delta robot have been obtained to ensure desired workspace with minimum dimensions with moth swarm algorithm (MSA) optimization and particle swarm optimization (PSO). Widely known PSO algorithm has been used for the measure to the performance of the MSA algorithm that is new to the literature. Joints of the robot actuated with the brushless DC (BLDC) motors. System has been controlled fractional-order PID (FOPID) controller. Also integer-order PID controller (IOPID) has been used to clearly see the performance of the FOPID with the aim of comparison. Parameters of both of these controllers are optimized with MSA optimization in equal conditions. When the optimization cost results and the performance test results are examined, it is seen that the FOPID controller performed better than IOPID controller. Designed Delta robot system has been tested with different scenarios, and robotic system has been achieve that this scenarios with high performance. [ABSTRACT FROM AUTHOR]

The delta robot can reach higher speeds than traditional serial-axis machines used in fused filament fabrication 3D printing. However, like serial machines, delta printers suffer from undesirable vibration at high speeds which degrades the quality of fabricated parts. This undesirable vibration has been suppressed in serial printers using linear model-inversion feedforward control methods like the filtered B-splines (FBS) approach. However, techniques like the FBS approach are computationally challenging to implement on delta 3D printers because of their coupled, position-dependent dynamics. In this paper, we propose a methodology to address the computational bottlenecks by (1) parameterizing the position-dependent portions of the dynamics offline to enable efficient computation of the model online, (2) computing models at sampled points (instead of every point) along the given trajectory, and (3) employing QR factorization to reduce the number of floating-point arithmetic operations associated with matrix inversion. In simulations, we report a computation time reduction of up to 23× using the proposed method when compared to using the computationally expensive exact LPV model—all while maintaining high tracking accuracy. Accordingly, we demonstrate significant quality improvements on parts printed at various positions on a commercial delta 3D printer using our proposed controller compared to a baseline alternative, which uses an LTI model from one position. Acceleration measurements during printing show that the improvement in print quality of the proposed controller is due to vibration reductions of up to 39% when compared to the baseline controller. [ABSTRACT FROM AUTHOR]

This paper presents a novel compliant Delta micromanipulator with low parasitic motions. Flexure joints are used to construct the compliant counterpart of the Delta robot. The rigid-body modelling technique is employed for forward and inverse kinematic modelling. The compliance analysis of the design is formulated by resorting to the matrix method. Then, finite-element-analysis (FEA) simulations are done to verify the analytical models. The results confirm with acceptable deviations. Compensation factor based correction in the kinematic model is then proposed, which reduces the errors even further. A comparison with the other reported designs reveals that the proposed design displays an overall superior performance in terms of errors and parasitic motions. For an expected 50 μ m motion, the maximum error is observed to be 0.422%, and the maximum parasitic motions in the x, y, and z directions are 0.044%, 0.095%, and 0.018%, respectively. [ABSTRACT FROM AUTHOR]

With the advancement of the times, robotics technology is also developing rapidly. Some large enterprises in China use robots to work in manufacturing and handling positions, and also make robots more and more widely used. This paper focuses on the trajectory planning strategy for three-degree-of-freedom high-speed parallel manipulator of Delta robot in Cartesian space under high-speed operation handling, the point-to-point "door" type handling operation trajectory under the condition of ensuring control accuracy and increasing productivity in intelligent packaging is established based on the inverse kinematics model of the manipulator. The 4–3–3-4 degree polynomial interpolation is presented to control height of obstacle avoidance and trajectory length, on this basis, the mapping relationship between the motion features in operation space and those in joint space is established. Taking into account the complexity of trajectory optimization due to multiple constraints, in order to reduce the difficulty of trajectory optimization, it is necessary to ensure smoothness and constrains of angular displacement, angular velocity and angular acceleration of each joint in space, an improved particle swarm optimization algorithm is proposed to optimize trajectory running time of the 4–3–3-4 degree polynomial interpolation. The simulation results by using Matlab indicate that the accurate and stable time-optimal trajectory planning of 4–3–3-4 degree polynomial interpolation can be achieved by means of the improved particle swarm optimization algorithm. Compared with other trajectory planning algorithms, the proposed algorithm is easier to implement, which not only improves the local convergence of particle swarm optimization algorithm, achieves the time optimal trajectory planning of Delta robot, but also realizes the controllability of obstacle avoidance height, therefore which realizes the fast, accurate and safe operation in intelligent packaging. [ABSTRACT FROM AUTHOR]

Solving the reachable workspaces of spatial hyper-redundant manipulators (SHRMs) formed by serially connected parallel manipulators is an important and challenging work. This study addresses the issue on reachable workspaces and establishes a novel CAD-VBbased workspace determination system for determining the reachable workspaces of SHRMs. The reachable workspace determination of a novel (3-RPS)+(3-SPR)+(3-RPS) SHRM, a triple delta-type SHRM, and a novel (3-RRS)+(3-SPR)+(3-RRS) SHRM shows the generality and effectiveness of the proposed approach. The system proposed in this study can contribute to reachable workspace analysis for SHRMs. [ABSTRACT FROM AUTHOR]

Iterative learning control (ILC) theory is based on the traditional assumptions of resetting condition and repetitive trajectory. To overcome these restrictions, a novel ILC is developed in this paper for MIMO uncertain nonlinear systems subject to external disturbances and performing nonrepetitive trajectory. The proposed ILC scheme works under alignment condition and nonrepetitive trajectory that can be varied from iteration to iteration in time interval length, in magnitude scale as well as in initial and final positions. A time-scale transformation is introduced and combined with Lyapunov method to synthesise the control law and to prove the asymptotic convergence. The tracking error converges to zero as the number of iterations increases. Simulation of pick-and-place operations is carried out on a parallel Delta robot in order to show the feasibility and the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

In the view of the problem of designing and optimization of interval type-2 fuzzy logic controller (IT2 FLC) for Delta robot trajectory control, a systematic design method is put forward in this paper. A type-1 fuzzy logic controller (T1 FLC) is designed and optimized. Then, three kinds of method to blur the T1 fuzzy membership functions are proposed to generate IT2 fuzzy sets from the optimized T1 fuzzy sets. A systematic analysis is carried out to study the relationship between blur methods, blur degree and output control surface of IT2 FLC. Output signal enhance coefficient is proposed to make sure the IT2 FLC to provide enough output signal. The optimized IT2 FLC is validated through a set of simulations and by comparing against its type-1 counterpart in the presence of external and internal uncertainties. The simulation results show the optimized IT2 FLC can provide better trajectory tracking performance. [ABSTRACT FROM AUTHOR]