Journal articles on the topic 'Servo task'
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1
Yu, Sui Ran, and Yun Wei Lu. "Design Task Decomposition in the Servo Press." Applied Mechanics and Materials 34-35 (October 2010): 1966–72. http://dx.doi.org/10.4028/www.scientific.net/amm.34-35.1966.
Abstract:
This research is to find a design method for the large scale and complex product system. Thus, we made an approach to possibly better solution with limited time, limited resources and limited costs. This paper aims to find a method to quantify the solving process of the first stage in the concurrent design – “task decomposition”, in order to make preparations necessary for the next two stages -“concurrent task process” and “convergent coordination”. According to product's functional unit, we first decentralized complex product system into sub-modules. Then determine the importance and coherence among these sub-modules by using analytic hierarchy (AHP). Combining the results of the two judgments, we further classify the sub-modules to form distributed sub-systems, so that different design teams can work more effectively and more efficiently during their respective period. Finally, we verify the usefulness and effectiveness of the distributed method with an example of design task decomposition in servo press.
2
Yu, Sui Ran, and Yun Wei Lu. "Design Task Decomposition in the Servo Press." Applied Mechanics and Materials 34-35 (October 2010): 981–87. http://dx.doi.org/10.4028/www.scientific.net/amm.34-35.981.
Abstract:
This research is to find a design method for the large scale and complex product system. Thus, we made an approach to possibly better solution with limited time, limited resources and limited costs. This paper aims to find a method to quantify the solving process of the first stage in the concurrent design – “task decomposition”, in order to make preparations necessary for the next two stages -“concurrent task process” and “convergent coordination”. According to product's functional unit, we first decentralized complex product system into sub-modules. Then determine the importance and coherence among these sub-modules by using analytic hierarchy (AHP). Combining the results of the two judgments, we further classify the sub-modules to form distributed sub-systems, so that different design teams can work more effectively and more efficiently during their respective period. Finally, we verify the usefulness and effectiveness of the distributed method with an example of design task decomposition in servo press.
3
Castano, A., and S. Hutchinson. "Visual compliance: task-directed visual servo control." IEEE Transactions on Robotics and Automation 10, no. 3 (June 1994): 334–42. http://dx.doi.org/10.1109/70.294208.
4
Liu, Dong, Ming Cong, Yu Du, Yunfei Zhang, and Clarence W. de Silva. "Visual attention servo control for task-specific robotic applications." International Journal of Control, Automation and Systems 11, no. 6 (November 29, 2013): 1241–52. http://dx.doi.org/10.1007/s12555-012-9505-6.
5
Molitor, Dirk Alexander, Viktor Arne, Daniel Spies, Florian Hoppe, and Peter Groche. "Task space control of ram poses of multipoint Servo Presses." Journal of Process Control 129 (September 2023): 103057. http://dx.doi.org/10.1016/j.jprocont.2023.103057.
6
Lou, Jingjing. "Predictive Control-Based Completeness Analysis and Global Calibration of Robot Vision Features." Computational Intelligence and Neuroscience 2021 (December 9, 2021): 1–12. http://dx.doi.org/10.1155/2021/7241659.
Abstract:
This paper provides an in-depth study and analysis of robot vision features for predictive control and a global calibration of their feature completeness. The acquisition and use of the complete macrofeature set are studied in the context of a robot task by defining the complete macrofeature set at the level of the overall purpose and constraints of the robot vision servo task. The visual feature set that can fully characterize the macropurpose and constraints of a vision servo task is defined as the complete macrofeature set. Due to the complexity of the task, a part of the features of the complete macrofeature set is obtained directly from the image, and another part of the features is obtained from the image by inference. The task is guaranteed to be completely based on a robust calibration-free visual serving strategy based on interference observer that is proposed to complete the visual serving task with high performance. To address the problems of singular values, local minima, and insufficient robustness in the traditional scale-free vision servo algorithm, a new scale-free vision servo method is proposed to construct a dual closed-loop vision servo structure based on interference observer, which ensures the closed-loop stability of the system through the Q-filter-based interference observer, while estimating and eliminating the interference consisting of hand-eye mapping model uncertainty and controlled robot input interference. The equivalent interference consisting of hand-eye mapping model uncertainty, controlled robot input interference, and detection noise is estimated and eliminated to obtain an inner-loop structure that presents a nominal model externally, and then an outer-loop controller is designed according to the nominal model to achieve the best performance of the system dynamic performance and robustness to optimally perform the vision servo task.
7
Chesi, Graziano, and Koichi Hashimoto. "Configuration and Robustness in Visual Servo." Journal of Robotics and Mechatronics 16, no. 2 (April 20, 2004): 178–85. http://dx.doi.org/10.20965/jrm.2004.p0178.
Abstract:
Effects of camera calibration errors on the point-to-point task are investigated in static-eye and hand-eye visual servoing realized with position-based and image-based control laws. For these four configurations, the effect of uncertainty on the extrinsic parameters is analyzed. The results show local stability for all configurations under small calibration errors. However, a steady state error is found in the hand-eye position-based configuration. Simulations have been done to confirm the theoretical results and evaluate the effects of the uncertainty in terms of stability region. Another contribution of the paper consists of providing a method for estimating the stability region robust against uncertainty directions for the static-eye position-based case with uncertainty on the camera centers.
8
Feemster, Matthew, Jenelle A. Piepmeier, Harrison Biggs, Steven Yee, Hatem ElBidweihy, and Samara L. Firebaugh. "Autonomous Microrobotic Manipulation Using Visual Servo Control." Micromachines 11, no. 2 (January 24, 2020): 132. http://dx.doi.org/10.3390/mi11020132.
Abstract:
This describes the application of a visual servo control method to the microrobotic manipulation of polymer beads on a two-dimensional fluid interface. A microrobot, actuated through magnetic fields, is utilized to manipulate a non-magnetic polymer bead into a desired position. The controller utilizes multiple modes of robot actuation to address the different stages of the task. A filtering strategy employed in separation mode allows the robot to spiral from the manipuland in a fashion that promotes the manipulation positioning objective. Experiments demonstrate that our multiphase controller can be used to direct a microrobot to position a manipuland to within an average positional error of approximately 8 pixels (64 µm) over numerous trials.
9
Qiu, Yu, Baoquan Li, Wuxi Shi, and Yimei Chen. "Concurrent-learning-based visual servo tracking and scene identification of mobile robots." Assembly Automation 39, no. 3 (August 5, 2019): 460–68. http://dx.doi.org/10.1108/aa-02-2018-024.
Abstract:
PurposeThe purpose of this paper is to present a visual servo tracking strategy for the wheeled mobile robot, where the unknown feature depth information can be identified simultaneously in the visual servoing process.Design/methodology/approachBy using reference, desired and current images, system errors are constructed by measurable signals that are obtained by decomposing Euclidean homographies. Subsequently, by taking the advantage of the concurrent learning framework, both historical and current system data are used to construct an adaptive updating mechanism for recovering the unknown feature depth. Then, the kinematic controller is designed for the mobile robot to achieve the visual servo trajectory tracking task. Lyapunov techniques and LaSalle’s invariance principle are used to prove that system errors and the depth estimation error converge to zero synchronously.FindingsThe concurrent learning-based visual servo tracking and identification technology is found to be reliable, accurate and efficient with both simulation and comparative experimental results. Both trajectory tracking and depth estimation errors converge to zero successfully.Originality/valueOn the basis of the concurrent learning framework, an adaptive control strategy is developed for the mobile robot to successfully identify the unknown scene depth while accomplishing the visual servo trajectory tracking task.
10
Yuksel, Tolga. "Sliding Surface Designs for Visual Servo Control of Quadrotors." Drones 7, no. 8 (August 14, 2023): 531. http://dx.doi.org/10.3390/drones7080531.
Abstract:
Autonomy is the main task of a quadrotor, and visual servoing assists with this task while providing fault tolerance under GPS failure. The main approach to visual servoing is image-based visual servoing, which uses image features directly without the need for pose estimation. The classical sliding surface design of sliding mode control is used by the linear controller law of image-based visual servoing, and focuses only on minimizing the error in the image features as convergence. In addition to providing convergence, performance characteristics such as visual-feature-convergence time, error, and motion characteristics should be taken into consideration while controlling a quadrotor under velocity limitations and disturbance. In this study, an image-based visual servoing system for quadrotors with five different sliding surface designs is proposed using analytical techniques and fuzzy logic. The proposed visual servo system was simulated, utilizing the moment characteristics of a preset shape to demonstrate the effectiveness of these designs. The stated parameters, convergence time, errors, motion characteristics, and length of the path, followed by the quadrotor, were compared for each of these design approaches, and a convergence time that was 46.77% shorter and path length that was 6.15% shorter were obtained by these designs. In addition to demonstrating the superiority of the designs, this study can be considered as a reflection of the realization, as well as the velocity constraints and disturbance resilience in the simulations.
11
Su, Wei Hua, Xu Dong Ren, Wen Chang Zhang, and Fu Niu. "Task-Oriented Servo Loops Control of a 6-DOF Manipulator for Rescue Robot." Applied Mechanics and Materials 404 (September 2013): 663–67. http://dx.doi.org/10.4028/www.scientific.net/amm.404.663.
Abstract:
The thesis research aimed to develop a novel approach to model and control a 6-DOF manipulator for specific tasks. The modeling and control method take into account velocity of the dynamical model. The camera and acquisition system were developed in order to significantly increase the bandwidth of the manipulator. Multi-Input and Multi-Output (MIMO) is used to optimally control the visual loop with respect to the proposed dynamical model. Experimental results on a 6-DOF manipulator for rescue robot are presented that validate the proposed model. Furthermore, a precise synchronization method is used to reduce the delays of image transfer and processing. The experiment results show a biggish improvement of the loop performance with respect to more classical control methods for 6-DOF manipulator.
12
Paccot, Flavien, and Helene Chanal. "A generic method for servo tuning based on dynamic modeling and task description." ISA Transactions 80 (September 2018): 542–53. http://dx.doi.org/10.1016/j.isatra.2018.07.002.
13
Woś, Piotr, and Ryszard Dindorf. "Synchronization of the movement for multi-cylinder electrohydraulic servo driver." EPJ Web of Conferences 269 (2022): 01069. http://dx.doi.org/10.1051/epjconf/202226901069.
Abstract:
The article presents the problem of synchronization of piston rods velocity of the multi-cylinder electro-hydraulic servo drive. This task was presented on the example of a heavily loaded mobile caterpillar platform. For levelling the platform, a four-post electro-hydraulic support mechanism with a proportional valve control system was used. A linear external controller to synchronize the movement of the cylinders was used and a non-linear internal control system for each of the cylinders lifting the platform.
14
Zou, Liying, Huiguang Li, Wei Zhao, and Lei Zhu. "Imaged-Based Visual Servo Control for a VTOL Aircraft." Mathematical Problems in Engineering 2017 (2017): 1–6. http://dx.doi.org/10.1155/2017/4806769.
Abstract:
This paper presents a novel control strategy to force a vertical take-off and landing (VTOL) aircraft to accomplish the pinpoint landing task. The control development is based on the image-based visual servoing method and the back-stepping technique; its design differs from the existing methods because the controller maps the image errors onto the actuator space via a visual model which does not contain the depth information of the feature point. The novelty of the proposed method is to extend the image-based visual servoing technique to the VTOL aircraft control. In addition, the Lyapunov theory is used to prove the asymptotic stability of the VTOL aircraft visual servoing system, while the image error can converge to zero. Furthermore, simulations have been also conducted to demonstrate the performances of the proposed method.
15
Zhao, Wenshuai, Xi Wang, Yifu Long, Zhenhua Zhou, and Linhang Tian. "Robust LQR Design Method for the Aero-Engine Integral Constant Pressure Drop Control Valve with High Precision." Aerospace 10, no. 5 (April 30, 2023): 428. http://dx.doi.org/10.3390/aerospace10050428.
Abstract:
The closed-loop constant pressure drop control valve is widely used in aero-engine fuel servo metering systems. However, the available constant pressure drop control valve cannot realize servo tracking without static error and, often, a high proportional gain is used to reduce the static error and improve the servo tracking performance, which reduces the stability margin. In this paper, an integral constant pressure drop control valve is designed, which consists of an integral controller and a stabilizing controller. Moreover, a robust LQR design method is proposed to complete the design task. Firstly, the controlled plant’s state–space model is derived, and the augmented model with tracking error is established based on the robust servo system design theory. Secondly, a servo controller with dual functions of integral control and stabilization control is constructed and decoupled, in which the stabilizing controller guarantees the asymptotic stability as well as the anti-disturbance performance, and the integral controller realizes the servo tracking without static error. Finally, based on the robust LQR design method, two key design parameters, including the integral control gain and the stabilization control gain, are designed to complete the design task. The simulation results indicate that, even when suffering 50 mm2 metered flow area step disturbance and 1 MPa inlet pressure step change, the designed integral constant pressure drop control valve can realize the function of servo tracking without static error. The static error is almost 0, the settling time is within 0.01 s, the overshoot is within 10%, and the phase margin is more than 55°.
16
Gu, Jinlin, Mingchao Zhu, Lihua Cao, Ang Li, Wenrui Wang, and Zhenbang Xu. "Improved Uncalibrated Visual Servo Strategy for Hyper-Redundant Manipulators in On-Orbit Automatic Assembly." Applied Sciences 10, no. 19 (October 5, 2020): 6968. http://dx.doi.org/10.3390/app10196968.
Abstract:
Aiming at on-orbit automatic assembly, an improved uncalibrated visual servo strategy for hyper-redundant manipulators based on projective homography is proposed. This strategy uses an improved homography-based task function with lower dimensions while maintaining its robustness to image defects and noise. This not only improves the real-time performance but also makes the joint space of hyper-redundant manipulator redundant to the homography-based task function. Considering that the kinematic parameters of the manipulator are easily changed in a space environment, the total Jacobian between the task function and manipulator joints is estimated online and used to construct a controller to directly control the manipulator joints without a kinematics model. When designing the controller, the above-mentioned redundancy is exploited to solve the problem of the over-limiting of the joint angles of the manipulator. The KF-SVSF method, which combines the optimality of the Kalman filter (KF) and the robustness of the smooth variable structure filter (SVSF), is introduced to the field of uncalibrated visual servos for the first time to perform the online estimation of the total Jacobian. In addition, the singular value filtering (SVF) method is adopted for the first time to avoid the interference caused by the unstable condition number of the estimated total Jacobian. Finally, simulations and experiments verify the superiority of this strategy in terms of its real-time performance and precision.
17
Naing, Zaw Myo. "Development of Servo Drive Positioning Control System Using PID Controller and Fuzzy Logic Controller." Proceedings of Universities. Electronics 26, no. 6 (December 2021): 583–88. http://dx.doi.org/10.24151/1561-5405-2021-26-6-583-588.
Abstract:
Servo drives are one of the most widely utilized devices in various mechanical systems and industrial applications to provide precise position control. The study of servo driver produc-tiveness and performance index is the important task. In this work, PID controller and fuzzy log-ic controller (FLC) were developed to control the position of a DC servo drive. The MATLAB Simulink program was investigated and implemented to calculate the values of servo drive pa-rameters, and a scheme for simulating the operation of a servo drive using different controllers was presented. A mathematical model of a DC servo drive for a positioning control system has been proposed. The control characteristics of the PID controller, fuzzy logic controller and fuzzy PID controller are compared. The simulation results have shown that the PID controller allows for an overshoot of about 1 % with a settling time of about 4 sec. The use of the fuzzy PID con-troller reduces the maximum overshoot to 1 % and decreases the settling time to 2 sec. As a re-sult, the fuzzy PID controller allows for better performance and efficiency compared to other controllers.
18
Medvedev, A. V., and E. M. Khalatov. "Method of individual selection of parts for selective assembly of electrohydraulic servo drives." VESTNIK of Samara University. Aerospace and Mechanical Engineering 22, no. 2 (June 28, 2023): 67–78. http://dx.doi.org/10.18287/2541-7533-2023-22-2-67-78.
Abstract:
A method for selecting parts and assembly units (hereinafter briefly referred to as parts) in sets for assembling a batch of electrohydraulic servo drives is presented, based on the measured (individual) mechanical and hydraulic characteristics of the parts. The preparatory stage is described: construction of a mathematical model of the product, determination of the parameters of parts and adjustments that have the greatest impact on the parameters of end products, formation of a system for assessing the quality of products in the batch, mathematical formulation of the task of selecting parts. The task of selecting parts is formulated as the assignment problem in the maximin formulation. A deterministic algorithm for solving the problem is presented, based on the branch and bound method and taking into account the fact that adjustments are made during the assembly of drives. A significant reduction in the number of steps (iterations) when searching for the optimal distribution of parts across assembly sets achieved due to the chosen mathematical formulation of the task, as well as due to the chosen strategy of selecting parts in the next assembly set. We suggest that an assembly set should include, first of all, the most troublesome parts the parameters of which do not allow obtaining a set, the projected quality indicator of which will be higher than the established value. At the same time, the negative impact of these parts on the product parameters is compensated by combining them with other parts in one assembly set. The results of mathematical modeling of assembling 992 drives with random formation of assembly sets and with individual selection of parts are presented. Modeling shows that as a result of implementing individual selection of parts in accordance with the described method, a significant reduction in the spread of parameters of end products within batches can be expected, as well as improvements in functional performance of the products. The presented method of individual selection of parts can be used in the assembly of various products.
19
Blajer, Wojciech, Robert Seifried, and Krzysztof Kołodziejczyk. "Diversity of Servo-Constraint Problems for Underactuated Mechanical Systems: A Case Study Illustration." Solid State Phenomena 198 (March 2013): 473–82. http://dx.doi.org/10.4028/www.scientific.net/ssp.198.473.
Abstract:
Underactuated mechanical systems are systems with fewer control inputs than degrees of freedom. Determination of an input control strategy that forces an underactuated system to complete specified in time outputs (servo-constraints), whose number is equal to the number of inputs, can be a challenging task. Diversity of the servo-constraint problems is discussed here using a simple spring-mass system mounted on a carriage (two degrees of freedom, one control input, and one specified in time output). A formulation of underactuated system dynamics which includes the output coordinates is motivated, with the governing equations arising either as ODEs (ordinary differential equations) or DAEs (differential-algebraic equations). Solutions to the servo-constraint problem are then discussed with reference to so-called non-flat systems (with internal dynamics) and differentially flat systems (no internal dynamics). Some computational issues related to the ODE and DAE formulations are finally discussed, and relevant simulation results for the sample case study are reported.
20
Precup, Radu-Emil, Stefan Preitl, Claudia-Adina Bojan-Dragos, Elena-Lorena Hedrea, Raul-Cristian Roman, and Emil M. Petriu. "A LOW-COST APPROACH TO DATA-DRIVEN FUZZY CONTROL OF SERVO SYSTEMS." Facta Universitatis, Series: Mechanical Engineering 20, no. 1 (April 8, 2022): 021. http://dx.doi.org/10.22190/fume220111005p.
Abstract:
Servo systems become more and more important in control systems applications in various fields as both separate control systems and actuators. Ensuring very good control system performance using few information on the servo system model (viewed as a controlled process) is a challenging task. Starting with authors’ results on data-driven model-free control, fuzzy control and the indirect model-free tuning of fuzzy controllers, this paper suggests a low-cost approach to the data-driven fuzzy control of servo systems. The data-driven fuzzy control approach consists of six steps: (i) open-loop data-driven system identification to produce the process model from input-output data expressed as the system step response, (ii) Proportional-Integral (PI) controller tuning using the Extended Symmetrical Optimum (ESO) method, (iii) PI controller parameters mapping onto parameters of Takagi-Sugeno PI-fuzzy controller in terms of the modal equivalence principle, (iv) closed-loop data-driven system identification, (v) PI controller tuning using the ESO method, (vi) PI controller parameters mapping onto parameters of Takagi-Sugeno PI-fuzzy controller. The steps (iv), (v) and (vi) are optional. The approach is applied to the position control of a nonlinear servo system. The experimental results obtained on laboratory equipment validate the approach.
21
Wang, Shunjiang, Zhaowei Ling, Ruichao Xu, Guiping Zhou, and Yifang Jin. "Adaptive back-stepping Control of Electro-hydraulic Servo system of Steam Turbine." Journal of Physics: Conference Series 2558, no. 1 (August 1, 2023): 012040. http://dx.doi.org/10.1088/1742-6596/2558/1/012040.
Abstract:
Abstract The parameters such as oil density and bulk elastic modulus of hydraulic oil in steam turbine electro-hydraulic servo system vary with ambient temperature, pressure, and other factors, and there are unmodeled dynamics in the system, so obtaining a satisfactory following effect is a challenging task for the electro-hydraulic servo(EHS) system. According to the principle of force balance and flow continuity, the mathematical model of a bilateral oil intake motor is established in this paper. On this basis, a back-stepping controller is designed, and an adaptive method is used to estimate uncertain parameters and disturbances. The designed control system is simulated and verified, and compared with the RBF control system after parameter optimization. The results show that the controller designed in this paper has good tracking performance and adaptability to uncertain parameters and external load disturbances.
22
Bożek, Andrzej. "Discovering Stick-Slip-Resistant Servo Control Algorithm Using Genetic Programming." Sensors 22, no. 1 (January 5, 2022): 383. http://dx.doi.org/10.3390/s22010383.
Abstract:
The stick-slip is one of negative phenomena caused by friction in servo systems. It is a consequence of complicated nonlinear friction characteristics, especially the so-called Stribeck effect. Much research has been done on control algorithms suppressing the stick-slip, but no simple solution has been found. In this work, a new approach is proposed based on genetic programming. The genetic programming is a machine learning technique constructing symbolic representation of programs or expressions by evolutionary process. In this way, the servo control algorithm optimally suppressing the stick-slip is discovered. The GP training is conducted on a simulated servo system, as the experiments would last too long in real-time. The feedback for the control algorithm is based on the sensors of position, velocity and acceleration. Variants with full and reduced sensor sets are considered. Ideal and quantized position measurements are also analyzed. The results reveal that the genetic programming can successfully discover a control algorithm effectively suppressing the stick-slip. However, it is not an easy task and relatively large size of population and a big number of generations are required. Real measurement results in worse control quality. Acceleration feedback has no apparent impact on the algorithms performance, while velocity feedback is important.
23
Ali, Kamran, Zhenwei Cao, Kamal Rsetam, and Zhihong Man. "Practical Adaptive Fast Terminal Sliding Mode Control for Servo Motors." Actuators 12, no. 12 (November 22, 2023): 433. http://dx.doi.org/10.3390/act12120433.
Abstract:
Position control of servo motor systems is a challenging task because of inevitable factors such as uncertainties, nonlinearities, parametric variations, and external perturbations. In this article, to alleviate the above issues, a practical adaptive fast terminal sliding mode control (PAFTSMC) is proposed for better tracking performance of the servo motor system by using a state observer and bidirectional adaptive law. First, a smooth-tangent-hyperbolic-function-based practical fast terminal sliding mode control (PFTSM) surface is designed to ensure not only fast finite time tracking error convergence but also chattering reduction. Second, the PAFTSMC is proposed for the servo motor, in which a two-way adaptive law is designed to further suppress the chattering and overestimation problems. More importantly, the proposed adaptive technique can update the switching gain according to the system uncertainties, which can provide high gain in the reaching phase and then decrease to the smallest value in the sliding phase to avoid the monotonically increasing gain that exists in most adaptation methods. Third, the finite-time stability of the closed-loop system is proved based on the Lyapunov theorem. Finally, the simulation studies and experimental tests verify the effectiveness of the proposed control in terms of better tracking, strong robustness, and reduced chattering, compared to existing algorithms.
24
ISHIBASHI, Ryota. "A study of the task space P-SD servo controller with the finger-tip tracing motion." Proceedings of JSME annual Conference on Robotics and Mechatronics (Robomec) 2016 (2016): 1P1–11b1. http://dx.doi.org/10.1299/jsmermd.2016.1p1-11b1.
25
Wang, Hongfei, and Yongkang Shi. "Design of UAV target tracking controller based on visual servo." Journal of Physics: Conference Series 2246, no. 1 (April 1, 2022): 012051. http://dx.doi.org/10.1088/1742-6596/2246/1/012051.
Abstract:
Abstract The task of tracking a moving target by the UAV has two major challenges: one is that the multi-angle and multi-scale changes caused by the target’s movement make the target detection more difficult, the other is that the stability and accurate of target tracking are difficult to guarantee. In order to solve these problems, using monocular vision to get the image information of the target and YOLOv4 is used to detect multi-angle and multi-scale moving targets. Then based on the image visual servo control method, the PID controller is designed, and the deviation between the target pixel and the ideal pixel is used as the input, the output of the controller is the desired pixel speed of the UAV in image coordinate system. the tracking speed of the UAV under the machine system is solved according to the image Jacobian matrix, and a tracking strategy is designed to improve the tracking accurate and stability. In the process of target tracking, the difference between the x-axis and Y-axis coordinates of the target center point and the image center point is less than 30 pixels. The results show that the proposed algorithm can keep the target in the center of the image.
26
Mohammed, Sanusi, Adamu Shehu, Shuaibu Sanda Hussaini, and Abubakar Usman Rumba. "The Design,Implementationand Performance Analysisof a Smart Fire Fighting Robot." International Journal of Scientific and Academic Research 03, no. 05 (2023): 01–08. http://dx.doi.org/10.54756/ijsar.2023.v3.5.1.
Abstract:
This research work Titled “Design and Implementation of a Smart Firefighting Robot” focused on developing a robotic system capable of moving to areas wherefiremen have to risk their lives to put off the fire.Fire disaster occur at any time and at any place without notice, which result in high losses.Due to the damage of buildings and explosive materials, it becomes a major task to save people and to put off the fire.The robot will reduce the risk of injury for firefighters and possible victims and minimize the monitory losses which increase considerably as fire duration increases. It consists of Ultrasonic sensormounted on the servo motor for obstacle detectionand equipped with flame sensors for detecting fire.It has a liquid-tank and spray mechanism for putting off the fire.The spring nozzle is mounted on the servo motor to cover a maximum area. The liquid is pumped from the tankwith a 12v pump.The robotic system is programmed using Arduino Uno board which served as the brain of the robotic system.
27
Chen, Z. H., Y. Wang, P. Ouyang, J. Huang, and W. J. Zhang. "A novel iteration-based controller for hybrid machine systems for trajectory tracking at the end-effector level." Robotica 29, no. 2 (April 27, 2010): 317–24. http://dx.doi.org/10.1017/s0263574710000159.
Abstract:
SUMMARYHybrid actuation systems consist of two types of motors: constant velocity (CV) motor and servo (SV) motor. The CV motor can produce a large power but with a poor task flexibility. On the other hand, the SV motor has an excellent task flexibility but with a small power capacity. Combination of these two types of motors into a coherent driver architecture for machine systems is extremely promising, because they complement each other. Existing studies on the hybrid actuation or machine system usually employ two servo motors, one of which substitutes the CV motor. This treatment compromises the control accuracy for the trajectory tracking at the end-effector. This paper presents a study on a new controller for the hybrid machine that considers one SV motor and one CV motor and for trajectory tracking at the end-effector level. A comparison of this new controller with the controller we developed previously is provided. A five-bar mechanism with two degrees of freedom is employed for the illustration purpose.
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Pliuhin, Vladyslav, Oleksandr Aksonov, Yevgen Tsegelnyk, Sergiy Plankovskyy, Volodymyr Kombarov, and Lidiia Piddubna. "Design and Simulation of a Servo-Drive Motor Using ANSYS Electromagnetics." Lighting Engineering & Power Engineering 60, no. 3 (December 30, 2021): 112–23. http://dx.doi.org/10.33042/2079-424x.2021.60.3.04.
Abstract:
The paper is devoted to determining the output parameters of a servomotor, which belongs to synchronous machines with permanent magnets, in order to further determine the characteristics of transient modes in the software package ANSYS Electromagnetics. RMxprt, part of ANSYS Electromagnetics, allows to determine the parameters of windings, losses, motor performance, but requires filling out a form with a complete set of geometric dimensions and winding data. Of course, such data are not available in the motor data sheet, so the first task solved in the paper is to determine all the necessary and sufficient parameters to perform the calculation in RMxprt. The results of the calculations were compared with the measurements on the experimental servomotor EMG-10APA22. This paper shows how to export a servomotor object from RMxprt to the Simplorer workspace, which is also part of the ANSYS Electromagnetics. According to the simulation results in ANSYS Simplorer, the characteristics of the transient modes of the servomotor powered by a stable three-phase source are obtained. Prospects for further research related to the improvement of the simulation model in ANSYS Simplorer are presented.
29
Wang, Yuxin, Hesheng Wang, Zhe Liu, and Weidong Chen. "Visual Servo-Collision Avoidance Hybrid Task by Considering Detection and Localization of Contact for a Soft Manipulator." IEEE/ASME Transactions on Mechatronics 25, no. 3 (June 2020): 1310–21. http://dx.doi.org/10.1109/tmech.2020.2974296.
30
Gao, Bingwei, and Yongtai Ye. "Research on Position / Velocity Synergistic Control of Electro Hydraulic Servo System." Recent Patents on Mechanical Engineering 13, no. 4 (October 13, 2020): 366–77. http://dx.doi.org/10.2174/2212797613999200420082115.
Abstract:
Background: In some applications, the requirements of electro-hydraulic servo system are not only precise positioning, but also the speediness capability at which the actuator is operated. Objective: In order to enable the system to achieve rapid start and stop during the work process, reduce the vibration and impact caused by the change of the velocity, at the same time improve the positioning accuracy, and further strengthen the stability and the work efficiency of the system, it is necessary to perform the synergistic control between the position and the velocity of the electrohydraulic servo system. Methods: In order to achieve synergistic control between the position and the velocity, a control method of velocity feed-forward and position feedback is adopted. That is, based on the position control, the speed feed-forward is added to the outer loop as compensation. The position control adopts the PID controller, and the velocity control adopts the adaptive fuzzy neural network controller. At the same time, the position and velocity sensors are used for feedback, and the deviation signals between the position and the velocity obtained by superimposing the feedback are used as the final input of the control object, thereby controlling the whole system. Results: The control effect of the designed position / velocity synergistic controller is verified by simulation and experiment. The results show that the designed controller can effectively reduce the vibration and impact caused by the change of the velocity, and greatly improve the response velocity and the position accuracy of the system. Conclusion: The proposed method provides technical support for multi-objective synergistic control of the electro-hydraulic servo system, completes the requirements of multi-task operation, improves the positioning accuracy and response velocity of the electro-hydraulic servo system, and realizes the synergy between the position and the velocity. In this article, various patents have been discussed.
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Chew, Zhe Zhi, Kok seng Eu, Kian Neng Yap, Tsung Heng Chiew, Yoon Ket Lee, Xian Zhu Lim, Julian Kok Ping Tan, and Yee Wai Sim. "AUTOMATIC ASSEMBLY OF INTERLOCKING BUILDING CUBES BY USING VISUAL SERVOING APPROACH." Suranaree Journal of Science and Technology 31, no. 1 (March 27, 2024): 010274(1–10). http://dx.doi.org/10.55766/sujst-2024-01-e0462.
Abstract:
Most of the robotic arms are set up for operation by the teach-and-repeat (T&R) technique, also known as coordinate-based control, using pre-recorded coordination values to generate robotic arm trajectories. This technique is inefficient because it requires teaching a robotic arm every single coordinate point to complete an operation. It is a manual, tedious and time-consuming task. Moreover, this task needs to be repeated if there are slight changes in the operation. This paper studied the visual servoing approach to replace the T&R technique in assembling different interlocking building cubes (IBC) combinations. The proposed method uses an image-based visual servo (IBVS) with a dynamic look-and-move system, and the eye-to-hand system, which requires computing the incremental joint angles of the robotic arm, a novel kinematic formula with a combination of Trigonometry formulas has been proposed in this paper. The experimental results show the feasibility of using a visual servoing approach to complete the assembly tasks without relying on the T&R technique and achieved an average success rate of 90% and an average of 40.2 seconds for task duration. Thus, this eliminates the tedious and time-consuming tasks of teaching the coordinate points to the robotic arms. Further improvement on the servo motor, camera and computer processor can be done to increase the accuracy, computation time and task duration in future.
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Hyun, J. H., and C. O. Lee. "Optimization of feedback gains for a hydraulic servo system by genetic algorithms." Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering 212, no. 5 (August 1, 1998): 395–401. http://dx.doi.org/10.1243/0959651981539569.
Abstract:
The optimal values of the five feedback gains of a double-loop controller for the speed control of an overcentred variable-displacement hydraulic motor are experimentally determined by using genetic algorithms. The reciprocal of the criterion of integration of time multiplied by absolute error is proposed as the fitness function that evaluates the performance of the control. The appropriate specification of the genetic algorithms and the search range of each control gain for the speed control system are presented. It is found that the near-optimal values of the feedback gains can be obtained within ten generations, which corresponds to about 100 experiments. The optimal gains are also obtained when the inertia or the supply pressure is varied. Optimized feedback gains are confirmed by plotting the fitness function in a given gain space. The fitness distribution indicates that finding the optimal feedback gains by manual tuning is an extremely time-consuming task, and that the genetic algorithm is an efficient scheme economizing time and labour, in optimizing feedback gains for hydraulic servo systems.
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Yamtuan, Kawin, Trirat Radomngam, and Pradya Prempraneerach. "Visual Servo Kinematic Control of Delta Robot using YOLOv5 Algorithm." Journal of Robotics and Control (JRC) 4, no. 6 (November 26, 2023): 818–31. http://dx.doi.org/10.18196/jrc.v4i6.19102.
Abstract:
Industrial delta robots with motion-and vision-base controllers, providing high-precision and fast/flexible motion, normally come with high cost and complex software. Low-cost delta robots with vision solution could be beneficial to vast industries to increase productivity and to reduce labor cost. A delta robot using a low-cost motion controller and an open-source vision system is developed to accomplish real-time visual servoing with high motion accuracy. In the low-cost motion controller, three parallel links’ upper-arm angles, computed from inverse kinematics for a given desired target position by a high-level computer, are used as reference position commands for three AC-motor drives. A low-level Arduino microcontroller is employed to convert these links’ angles to high-frequency pulses and on-off signals for synchronously controlling three motor angles and direction. Experimental results of a point-to-point motion tracking exhibit high-precision repeatability. Synchronous pulse generation from Arduino microcontroller and structural misalignments of parallel links are major challenges for achieving high motion accuracy. For the vision-based system, the YOLOv5 algorithm is implemented along with a Python GUI Application. Then, the visual-servo performance is evaluated on localization accuracy and recognition rate of 3-color objects. However, a partial object occlusion can reduce the visual classification rate. A sorting task of 4-category medicine boxes demonstrate a high-speed pick-and-place operation using the low-cost visual-servo system of this delta robot. Therefore, integration of low-cost visual servoing with this delta robot can revolutionize various industries, like automobile, pharmaceutical, and food sectors, in separating, sorting and packing applications.
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Stojanovic, Vladimir. "Fault-tolerant control of a hydraulic servo actuator via adaptive dynamic programming." Mathematical Modelling and Control 3, no. 3 (2023): 181–91. http://dx.doi.org/10.3934/mmc.2023016.
Abstract:
<abstract><p>The fault-tolerant control problem of a hydraulic servo actuator in the presence of actuator faults is studied utilizing adaptive dynamic programming. This task is challenging because of unknown system dynamics, uncertain disturbances or unmeasurable system states of such highly nonlinear systems in real applications. The aim is to achieve asymptotic tracking and actuator faults compensation by minimizing some predefined performance index. The discrete-time algebraic Riccati equation is iteratively solved by the adaptive dynamic programming approach. For practical reasons, adaptive dynamic programming techniques and fault compensation are integrated to iteratively compute an approximated optimal fault-tolerant control using real-time input/output data without any a priori knowledge of the system dynamics and unmeasurable states. As a result, a fault-tolerant control of hydraulic servo actuator is then designed based on adaptive dynamic programming via output feedback. Also, the convergence analysis of a data-driven fault-tolerant control is theoretically shown as well. Finally, intensive simulation results are given to prove the validity and merits of the developed data-driven fault-tolerant control strategy.</p></abstract>
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He, Xiaolong, Yuan Wang, Yapeng Shi, Chenhao Du, Bin Yu, Qiwei Zhang, Zuojian Xie, Yan Xie, and Xuekun Hou. "Parameter Sensitivity Analysis of a Brake Pressure Control System in Aviation Using an Electro-Hydraulic Servo Valve." Electronics 11, no. 5 (February 28, 2022): 746. http://dx.doi.org/10.3390/electronics11050746.
Abstract:
The landing gear system has the task of bearing the weight of the aircraft, bearing the impact load, and providing the braking function in the process of the aircraft taxiing, take-off, and landing. There are many parameters in the aviation brake pressure servo valve-controlled cylinder system (ABPSVCS) which will have a significant influence on the dynamic behavior of the system. Sensitivity analysis is an effective method to analyze the influence of system parameters on system characteristics, especially for nonlinear systems. The trajectory sensitivity method based on the description of system state space is used for the parameter sensitivity analysis of the ABPSVCS. By grouping various parameters for sensitivity analysis, the law of parameter sensitivity of each group is obtained, and the results are verified by experiments. The results can lay a theoretical and experimental foundation for the related research work of the aviation brake pressure servo valve.
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Arif, Zubair, and Yili Fu. "Mix Frame Visual Servo Control Framework for Autonomous Assistive Robotic Arms." Sensors 22, no. 2 (January 14, 2022): 642. http://dx.doi.org/10.3390/s22020642.
Abstract:
Assistive robotic arms (ARAs) that provide care to the elderly and people with disabilities, are a significant part of Human-Robot Interaction (HRI). Presently available ARAs provide non-intuitive interfaces such as joysticks for control and thus, lacks the autonomy to perform daily activities. This study proposes that, for inducing autonomous behavior in ARAs, visual sensors integration is vital, and visual servoing in the direct Cartesian control mode is the preferred method. Generally, ARAs are designed in a configuration where its end-effector’s position is defined in the fixed base frame while orientation is expressed in the end-effector frame. We denoted this configuration as ‘mixed frame robotic arms’. Consequently, conventional visual servo controllers which operate in a single frame of reference are incompatible with mixed frame ARAs. Therefore, we propose a mixed-frame visual servo control framework for ARAs. Moreover, we enlightened the task space kinematics of a mixed frame ARAs, which led us to the development of a novel “mixed frame Jacobian matrix”. The proposed framework was validated on a mixed frame JACO-2 7 DoF ARA using an adaptive proportional derivative controller for achieving image-based visual servoing (IBVS), which showed a significant increase of 31% in the convergence rate, outperforming conventional IBVS joint controllers, especially in the outstretched arm positions and near the base frame. Our Results determine the need for the mixed frame controller for deploying visual servo control on modern ARAs, that can inherently cater to the robotic arm’s joint limits, singularities, and self-collision problems.
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Duan, Qianwen, Qiunong He, Yao Mao, Xi Zhou, and Qintao Hu. "Proximate Time-Optimal Servomechanism Based on Transition Process for Electro-Optical Set-Point Tracking Servo System." Applied Sciences 9, no. 23 (November 29, 2019): 5201. http://dx.doi.org/10.3390/app9235201.
Abstract:
Set-point tracking servo systems encounter the problem of the trade-off between the swiftness and smoothness in tracking task. To deal with this problem, the proximate time-optimal servomechanism based on transition process (PTSTP) is proposed in this paper. The PTSTP control scheme incorporates a transition process (TP) into the framework of proximate time-optimal servomechanism (PTOS) to eliminate the conservatism of the original PTOS without the controller changing. The target position signal amplitude and the ultimate ability of actuator are utilized to design the time-optimal TP to make the jumping target position signal turns to a smooth signal, which can significantly reduce system overshoot. Therefore, the system swiftness and smoothness performance are guaranteed by PTSTP. Then, the stability of the proposed method is analyzed theoretically. Finally, the experimental results show that the controlled system is able to track the target position signal with different amplitude fast and smoothly in an electro-optical set-point tracking servo system.
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Lee, Kyeong Ha, Seung Guk Baek, Hyouk Ryeol Choi, Hyungpil Moon, Sang-Hoon Ji, and Ja Choon Koo. "Feedforward model-inverse position control of three-stage servo-valve using zero magnitude error tracking control." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 233, no. 7 (July 5, 2018): 2340–48. http://dx.doi.org/10.1177/0954406218786533.
Abstract:
Three-stage servo-valves are popularly used in hydraulic systems that require large flow rate and high pressure. For a proper control of flow direction and flow rate fed into a hydraulic actuator, securing a proper position control bandwidth is a critical task for the servo-valve. In this paper, a set of popular control methods are systematically studied and a control method is selected. It is proven that the feedforward model-inverse control is the most effective method in terms of the control bandwidth. In the present work, the feedforward closed-loop architecture is adopted and the closed-loop system is estimated in a linear discrete-time transfer function by recursive least squares method. On recognizing a nonminimum phase zero problem, this work implements the zero magnitude error tracking control, an approximate model-inverse technique, in order to overcome the problem. As a result, the effectiveness of the proposed feedforward model-inverse position control strategy is verified.
39
Filaretov, V., A. Zuev, A. Zhirabok, and A. Protsenko. "Development of Fault Identification System for Electric Servo Actuators of Multilink Manipulators Using Logic-Dynamic Approach." Journal of Control Science and Engineering 2017 (2017): 1–8. http://dx.doi.org/10.1155/2017/8168627.
Abstract:
This paper presents the method of synthesis of faults identification systems for electric servo actuators of multilink manipulators. These actuators are described by nonlinear equations with significantly changing coefficients. The proposed method is based on logic-dynamic approach for design of diagnostic observers for fault detection and isolation. An advantage of this approach is that it allows studying systems with nonsmooth nonlinearities by linear methods only. For solving the task of faults identification, a residual signal feedback was proposed to be used for observers. The efficiency of the proposed fault identification system was confirmed by results of simulation.
40
Righettini, Paolo, Roberto Strada, and Filippo Cortinovis. "General Procedure for Servo-Axis Design in Multi-Degree-of-Freedom Machinery Subject to Mixed Loads." Machines 10, no. 6 (June 8, 2022): 454. http://dx.doi.org/10.3390/machines10060454.
Abstract:
The motion performances of multi-axis machinery are strongly related to the proper design of the servo axes driving the actuated joints, which must fulfil motion requests in terms of speed and torque for the motion design task. Multi-degree-of-freedom machinery highlights, at the joint level, mixed-load conditions due to high dynamic movements and external working forces. Moreover, such systems have a dynamic coupling between the axes due to their mechanical configuration. This mixed-load condition makes the servo-axes design, whose result is the selection of the couple power drive system and transmission, not a trivial procedure. This paper proposes an extensive theoretical discussion that leads to a general procedure for the direct design of the servo axes of multi-degree-of-freedom machinery subject to a mixed-load condition and dynamic coupling between the mechanical joints. The proposed procedure starts with identifying the loads required on the actuated joints without distinguishing between the different contributions. Then, in a few steps, the methodology leads to the direct choice of the PDS/transmission units through a single graphical representation where the load’s peak, thermal and speed conditions are highlighted, along with the possible PDSs and transmissions. The graphical representation proposed also allows the easy and efficient analysis of the effect of transmission selection on the torque and speed margins. Finally, the paper presents the effectiveness of the proposed procedure, applied to the design of the servo axes of a linear delta robot.
41
Yao, Jianjun, Xiancheng Wang, Shenghai Hu, and Wei Fu. "Adaline neural network-based adaptive inverse control for an electro-hydraulic servo system." Journal of Vibration and Control 17, no. 13 (February 24, 2011): 2007–14. http://dx.doi.org/10.1177/1077546310395972.
Abstract:
Based on adaptive inverse control theory, combined with neural network, neural network adaptive inverse controller is developed and applied to an electro-hydraulic servo system. The system inverse model identifier is constructed by neural network. The task is accomplished by generating a tracking error between the input command signal and the system response. The weights of the neural network are updated by the error signal in such a way that the error is minimized in the sense of mean square using (LMS) algorithm and the neural network is close to the system inverse model. The above steps make the gain of the serial connection system close to unity, realizing waveform replication function in real-time. To enhance its convergence and robustness, the normalized LMS algorithm is applied. Simulation in which nonlinear dead-zone is considered and experimental results demonstrate that the proposed control scheme is capable of tracking desired signals with high accuracy and it has good real-time performance.
42
Qadri, Mansoor Zahoor, Ahsan Ali, and Inam-ul-Hassan Sheikh. "HYBRID ITERATIVE LEARNING CONTROL FOR POSITION TRACKING OF AN ELECTRO HYDRAULIC SERVO SYSTEM." NED University Journal of Research XVI, no. 2 (March 1, 2019): 31–42. http://dx.doi.org/10.35453/nedjr-ascn-2018-0046.
Abstract:
Accurate position control of an electro hydraulic servo system (EHSS) is a challenging task due to inherent system nonlinearities, parametric variations and un-modelled dynamics. Since feedback controllers alone cannot provide perfect tracking control, an integration of feedback and feed forward controller is required. A cascaded iterative learning control (ILC) technique for position control of EHSS is proposed in this paper. ILC is a feed forward controller which modifies the reference signal for a feedback fractional order proportional-integral-derivative (PID) controller by learning through current control input and previous error obtained through trails. Unlike other feed forward controllers, ILC works on signal instead of system which eliminates the need of complete knowledge of the system. As compared to other controllers, the proposed technique provides fast convergence without the need of reconfiguring the existing control loop. Simulation and experiments revealed the effectiveness of the proposed technique for EHSS. The obtained results indicated eight percent improvement in rise time and nearly twenty one percent improvement in the settling time.
43
Ur Rahman, Muhammad Zia, Muhammad Tanveer Riaz, M. M. Sayed Al Mahmud, Mohsin Rizwan, and Muhammad Ahmad Choudhry. "The Prescribed Fixed Structure Intelligent Robust Control of an Electrohydraulic Servo System." Mathematical Problems in Engineering 2022 (March 8, 2022): 1–12. http://dx.doi.org/10.1155/2022/5144602.
Abstract:
The paper is focused to design a robust and a simple fixed structure H ∞ control synthesis for an Electrohydraulic Servo System (EHSS) and comparing its performance with the conventional H ∞ controller and the classical proportional integral derivative (PID) controller. The precise position tracking of the piston load of EHSS system using classical PID controller is a difficult task due to some non-linear properties of EHSS and the dynamic behaviour of its parameters. The conventional H ∞ controllers also have constraints on gain ( H ∞ norm) for typical design requirement such as the speed of response, higher order, complex structure, control bandwidth, and robust stability. To overcome the above limitations, the proposed synthesis is formulated in the MATLAB. The proposed synthesis has fixed order and fixed structure and is also a linear robust controller. The control parameters of proposed synthesis are tuned using Genetic Algorithm optimization in MATLAB. Another advantage of this design is to use higher order complex shaping fillers to shape the close loop sensitivity S s and complementary sensitivity T s for the desired robust performance, without effecting the structure fixed of proposed synthesis. The order of the proposed controller is not affected by using the higher order complex weights transfer functions W s s and W T s on sensitivity and complementary sensitivity, respectively, whereas the structure of the conventional H ∞ controller becomes more complex due to higher order shaping weights. Model of the Electrohydraulic Servo System is validated experimentally, and results of proposed robust synthesis are compared with conventional H ∞ controller and the classical PID.
44
Guo, Yong Feng, Song Luo, Ze Bin Ling, and Xiao You Zhang. "Research of Drives of Power Amplifiers of Magnetic Levitation Servo Spindle Applied to Micro EDM Based on FPGA." Key Engineering Materials 621 (August 2014): 564–69. http://dx.doi.org/10.4028/www.scientific.net/kem.621.564.
Abstract:
The drives of power amplifiers of magnetic levitation servo spindle applied to micro EDM (Electron discharge machining) based on FPGA (Field programmable gate array) are developed. The drive module that produces the PWM (Pulse width modulation) waves that conform to the requirements of spindle power amplifiers involving three-level half bridge switch power amplifier, three-level full bridge switch power amplifier and motor power amplifier, according to input of action values from magnetic levitation servo spindle controller DSP (Digital signal processor) is designed. Multi-PWM producing algorithm by single timer with multi comparing nodes is proposed. After being applied to control system of magnetic levitation servo spindle, the drives accomplish conversion from DSP action values to PWM waves. The PWMs that drive radial coil current power amplifier have phase difference of 180°. The PWMs that drive axial coil current power amplifier have dead zone time and their wave shapes are complementary. The PWMs that drive the motor power amplifier conform to requirements of power amplifier chip LMD18200. Using FPGA to realize the drive function of spindle power amplifier makes the drive design more flexible, resource distribution of DSP more optimized, the task of algorithms running more centralized, and the drives module gets simpler and more reliable because the phase shift circuit and dead zone circuit are cancelled but the function of phase shift and dead zone is reserved.
45
Mandal, Kingshuk, Dipankar Bose, Souren Mitra, and Soumya Sarkar. "Experimental investigation of process parameters in WEDM of Al 7075 alloy." Manufacturing Review 7 (2020): 30. http://dx.doi.org/10.1051/mfreview/2020021.
Abstract:
Process parameters selection is a critical task in wire electro-discharge machining (WEDM). The parameter settings would vary when a material to be machined is changed. In the present study, experimental investigation has been carried out for appropriate selection of process parameters in WEDM of Al 7075. It has been perceived that pulse on time (Ton), arc on time (Aon) pulse off time (Toff), arc off time (Aoff), servo sensitivity (Sc), wire tension (Wt) and servo voltage (Sv) are the major influencing factors on machining speed (Vc), corner error (Ce) and surface roughness (Ra) for this alloy. It is also observed that selected seven process parameters are essential for effective machining of Al 7075 alloy. Finally, three-dimensional (3D) surface topography has been analysed to determine the characteristics of the machined surface.
46
Lai, Ningbin, Yanjie Chen, Jiacheng Liang, Bingwei He, Hang Zhong, and Yaonan Wang. "An onboard-eye-to-hand visual servo and task coordination control for aerial manipulator based on a spherical model." Mechatronics 82 (April 2022): 102724. http://dx.doi.org/10.1016/j.mechatronics.2021.102724.
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Fok, Chien-Liang, Gwendolyn Johnson, John D. Yamokoski, Aloysius Mok, and Luis Sentis. "ControlIt! — A Software Framework for Whole-Body Operational Space Control." International Journal of Humanoid Robotics 13, no. 01 (March 2016): 1550040. http://dx.doi.org/10.1142/s0219843615500401.
Abstract:
Whole Body Operational Space Control (WBOSC) enables floating-base highly redundant robots to achieve unified motion/force control of one or more operational space objectives while adhering to physical constraints. It is a pioneering algorithm in the field of human-centered Whole-Body Control (WBC). Although there are extensive studies on the algorithms and theory behind WBOSC, limited studies exist on the software architecture and APIs that enable WBOSC to perform and be integrated into a larger system. In this paper, we address this by presenting ControlIt!, a new open-source software framework for WBOSC. Unlike previous implementations, ControlIt! is multi-threaded to increase maximum servo frequencies using standard PC hardware. A new parameter binding mechanism enables tight integration between ControlIt! and external processes via an extensible set of transport protocols. To support a new robot, only two plugins and a URDF model is needed — the rest of ControlIt! remains unchanged. New WBC primitives can be added by writing Task or Constraint plugins. ControlIt!’s capabilities are demonstrated on Dreamer, a 16-DOF torque controlled humanoid upper body robot containing both series elastic and co-actuated joints, and using it to perform a product disassembly task. Using this testbed, we show that ControlIt! can achieve average servo latencies of about 0.5[Formula: see text]ms when configured with two Cartesian position tasks, two orientation tasks, and a lower priority posture task. This is 10 times faster than the 5[Formula: see text]ms that was achieved using UTA-WBC, the prototype implementation of WBOSC that is both application and platform-specific. Variations in the product’s position is handled by updating the goal of the Cartesian position task. ControlIt!’s source code is released under LGPL and we hope it will be adopted and maintained by the WBC community for the long term as a platform for WBC development and integration.
48
Ayazbay, Abu-Alim, Gani Balabyev, Sandugash Orazaliyeva, Konrad Gromaszek, and Algazy Zhauyt. "Trajectory Planning, Kinematics, and Experimental Validation of a 3D-Printed Delta Robot Manipulator." International Journal of Mechanical Engineering and Robotics Research 13, no. 1 (2024): 113–25. http://dx.doi.org/10.18178/ijmerr.13.1.113-125.
Abstract:
This paper presents the implementation, trajectory planning, kinematics, and experimental validation of an open-source 3D-printed delta robot manipulator. The robot’s hardware consists of three servo motors, an Arduino Uno microcontroller, and a Pulse Width Modulation (PWM) servo module. The software includes a trapezoidal velocity profile planner and an inverse and forward kinematics solver to calculate the motor angles required to achieve a desired end-effector position in task space. The 3D printed parts were obtained from an open-source Thingiverse project and assembled to form the robot’s kinematic structure. The robot’s performance was evaluated in terms of its accuracy, repeatability, and maximum speed for a pick-and-place task. Experimental results show that the robot can achieve a positioning accuracy of 2.2 mm, with a top speed of 0.4 m/s, 30 picks per minute, and load carrying capacity up to 200 g. These results are satisfactory, considering the ease of assembly and the cost-effectiveness of the robot. The comparison of the calculated motor angles with actual motor angles obtained through additional potentiometer wires soldering shows promising results. The proposed robot’s cost-effective characteristics, utilization of open-source additive manufacturing, and motion planning algorithms make it suitable for various applications, including education, research, and small-scale industrial applications.
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Reddy, V. Madhu Smitha, Y. Naveen kumar Reddy, R. Manideep, K. Siva Kumar, U. Srivastav, and M. Kalpana. "Design and Fabrication of 3D-Printed Robotic Arm by Using Stepper Motor." International Journal for Research in Applied Science and Engineering Technology 12, no. 4 (April 30, 2024): 1556–65. http://dx.doi.org/10.22214/ijraset.2024.60124.
Abstract:
Abstract: The Main technology of this proposed work was to design and fabrication of pick and place robotic arm by 3d-printing technology. The robot arm will be designed with four degree of freedom and programmed to accomplish accurately simple light material pick and place task to assist in the production line in any industry. ARDUNO an open-source computer hardware and software is applied to control robot arm by driving four servo motors to be capable to modify the position wireless control was done by using a Smartphone with android operating system through a Bluetooth module. The robotic arm Working and its performance in execution of pick and place task should be analyzed
50
Leimeister, Mareike, Athanasios Kolios, and Maurizio Collu. "Development and Verification of an Aero-Hydro-Servo-Elastic Coupled Model of Dynamics for FOWT, Based on the MoWiT Library." Energies 13, no. 8 (April 16, 2020): 1974. http://dx.doi.org/10.3390/en13081974.
Abstract:
The complexity of floating offshore wind turbine (FOWT) systems, with their coupled motions, aero-hydro-servo-elastic dynamics, as well as non-linear system behavior and components, makes modeling and simulation indispensable. To ensure the correct implementation of the multi-physics, the engineering models and codes have to be verified and, subsequently, validated for proving the realistic representation of the real system behavior. Within the IEA (International Energy Agency) Wind Task 23 Subtask 2 offshore code-to-code comparisons have been performed. Based on these studies, using the OC3 phase IV spar-buoy FOWT system, the Modelica for Wind Turbines (MoWiT) library, developed at Fraunhofer IWES, is verified. MoWiT is capable of fully-coupled aero-hydro-servo-elastic simulations of wind turbine systems, onshore, offshore bottom-fixed, or even offshore floating. The hierarchical programing and multibody approach in the object-oriented and equation-based modeling language Modelica have the advantage (over some other simulation tools) of component-based modeling and, hence, easily modifying the implemented system model. The code-to-code comparisons with the results from the OC3 studies show, apart from expected differences due to required assumptions in consequence of missing data and incomplete information, good agreement and, consequently, substantiate the capability of MoWiT for fully-coupled aero-hydro-servo-elastic simulations of FOWT systems.