Research on Interpolation Control of 6-DOF Water Cutting Robot

2010 ◽  
Vol 455 ◽  
pp. 257-263
Author(s):  
Ming Hong Xie ◽  
W. Wang

In order to get the exact water cutting of the complexity shape, the 6-DOF robot kinematics model is put forward. The gesture of every point can be calculated in real-time through NC interpolation algorithm of the expected discrete points on the track. On the basis of the matrix of position and gesture, a precise control method of 6-DOF water cutting robot trajectory and attitude of the end is proposed which comes from the improved NC-based code and could get any angle cutting surface, which is easy to program off-line. Finally, the simulation verity of NC interpolation control is made by VC and MATLAB tools.

Author(s):  
Lixian Zhang ◽  
Xiao-shan Gao ◽  
Hongbo Li

In this paper, a multi-period turning interpolation algorithm, with real-time look-ahead scheme based on S-curve control method, is presented. In this interpolation algorithm, the geometric precision and the dynamic performance are both satisfied. The machining efficiency is improved by multi-period turning transition, and the precision is also improved by S-curve control method. The computational efficiency of this algorithm meets the need of real-time machining. In addition, there is no accumulated error. At last, this algorithm is verified the validation by the experiments on 3-axis CNC machine.


Author(s):  
Tri Cong Phung

Controlling accurately the position and velocity of robots in a given time is an important requirement in the industry. The open-source real-time operating systems not only have more advantages than the normal operating systems in both economy and flexibility but also meet the needs. This paper concentrates on building algorithms for controlling the robot trajectory in time using a modern real-time operating system called Linux-Xenomai. Firstly, the paper analyzes several advantages of the real-time operating system Linux-Xenomai comparing general operating systems and other real-time operating systems. Secondly, a real-time controller of a 5 degree-of-freedom (DOF) robot is built based on the real-time operating system Linux-Xenomai. After that, the paper proposes algorithms to test the ability of working in time of the robot. Finally, the real experiments are done to verify the proposed algorithms.


2011 ◽  
Vol 52-54 ◽  
pp. 417-423
Author(s):  
Xiao Peng Li ◽  
Hong Wei Ma ◽  
Wei Jian Li ◽  
Chuan Wei Wang

It is higher superior of the caterpillar mobile robots to others types of robots in unknown complex environment, the advantage is apparently; but the issue is, it is difficulty in exact analyzing the posture of the robot kinematics model. In this paper, the new ideas proposed in the view of this issue, on the solution of posture motion model in the non-structural environment, motion agencies is transformed by the equivalent mechanism transformation, a fixed posture on the ground movement model is established by the screw theory. The posture model of non-holonomic constraints multi-joint caterpillar robot could be transferred into a kinematics model of parallel mechanism posture. Besides, the posture control method on over-obstacle stability is proposed, analyzing with the controlling experiment.


2021 ◽  
Vol 54 (1-2) ◽  
pp. 102-115
Author(s):  
Wenhui Si ◽  
Lingyan Zhao ◽  
Jianping Wei ◽  
Zhiguang Guan

Extensive research efforts have been made to address the motion control of rigid-link electrically-driven (RLED) robots in literature. However, most existing results were designed in joint space and need to be converted to task space as more and more control tasks are defined in their operational space. In this work, the direct task-space regulation of RLED robots with uncertain kinematics is studied by using neural networks (NN) technique. Radial basis function (RBF) neural networks are used to estimate complicated and calibration heavy robot kinematics and dynamics. The NN weights are updated on-line through two adaptation laws without the necessity of off-line training. Compared with most existing NN-based robot control results, the novelty of the proposed method lies in that asymptotic stability of the overall system can be achieved instead of just uniformly ultimately bounded (UUB) stability. Moreover, the proposed control method can tolerate not only the actuator dynamics uncertainty but also the uncertainty in robot kinematics by adopting an adaptive Jacobian matrix. The asymptotic stability of the overall system is proven rigorously through Lyapunov analysis. Numerical studies have been carried out to verify efficiency of the proposed method.


2021 ◽  
pp. 104063872199481
Author(s):  
Yixin Xiao ◽  
Fan Yang ◽  
Fumin Liu ◽  
Hangping Yao ◽  
Nanping Wu ◽  
...  

The H2 subtypes of avian influenza A viruses (avian IAVs) have been circulating in poultry, and they have the potential to infect humans. Therefore, establishing a method to quickly detect this subtype is pivotal. We developed a TaqMan minor groove binder real-time RT-PCR assay that involved probes and primers based on conserved sequences of the matrix and hemagglutinin genes. The detection limit of this assay was as low as one 50% egg infectious dose (EID50)/mL per reaction. This assay is specific, sensitive, and rapid for detecting avian IAV H2 subtypes.


2021 ◽  
Vol 11 (13) ◽  
pp. 6224
Author(s):  
Qisong Zhou ◽  
Jianzhong Tang ◽  
Yong Nie ◽  
Zheng Chen ◽  
Long Qin

The cable-driven hyper-redundant snake-like manipulator (CHSM) inspired by the biomimetic structure of vertebrate muscles and tendons, which consists of numerous joint units connected adjacently driven by elastic materials with hyper-redundant DOF, performs flexible kinematic skills and competitive compound capability under complicated working circumstances. Nevertheless, the drawback of lacking the ability to perceive the environment to perform intelligently in complex scenarios leaves a lot to be improved, which is the original intention to introduce visual tracking feedback acting as an instructor. In this paper, a cable-driven snake-like robotic arm combined with a visual tracking technique is introduced. A visual tracking approach based on dual correlation filter is designed to guide the CHSM in detecting the target and tracing after its trajectory. Specifically, it contains an adaptive optimization for the scale variation of the tracking target via pyramid sampling. For the CHSM, an explicit kinematics model is derived from its specific geometry relationships and followed by a simplification for the inverse kinematics based on some assumption or limitation. A control scheme is brought up to combine the kinematics with visual tracking via the processing tracking errors. The experimental results with a practical prototype validate the availability of the proposed compound control method with the derived kinematics model.


Author(s):  
Wolf Schulze ◽  
Maurizio Zajadatz ◽  
Michael Suriyah ◽  
Thomas Leibfried

AbstractA test bed for the evaluation of novel control methods of inverters for renewable power generation is presented. The behavior of grid-following and grid-forming control in a test scenario is studied and compared.Using a real-time capable control platform with a cycle time of 50 µs, control methods developed with Matlab/Simulink can be implemented. For simplicity, a three-phase 4‑quadrant voltage amplifier is used instead of an inverter. Thus, the use of modulation and switched power semiconductors can be avoided. In order to show a realistic behavior of a grid-side filter, passive components can be automatically connected as L‑, LC- or LCL-filter. The test bed has a nominal active power of 43.6 kW and a nominal voltage of 400 V.As state-of-the-art grid-following control method, a current control in the d/q-system is implemented in the test bed. A virtual synchronous machine, the Synchronverter, is used as grid-forming control method. In combination with a frequency-variable grid emulation, the behavior of both control methods is studied in the event of a load connection in an island grid environment.


2021 ◽  
Vol 143 (4) ◽  
Author(s):  
Erhan Yumuk ◽  
Müjde Güzelkaya ◽  
İbrahim Eksin

Abstract In this study, a novel design method for half-cycle and modified posicast controller structures is proposed for a class of the fractional order systems. In this method, all required design variable values, namely, the input step magnitudes and their application times are obtained as functions of fractional system parameters. Moreover, empirical formulas are obtained for the overshoot values of the compensated system with half-cycle and modified posicast controllers designed utilizing this method. The proposed design methodology has been tested via simulations and ball balancing real-time system. It is observed that the derived formulas are in coherence with outcomes of the simulation and real-time application. Furthermore, the performance of modified posicast controller designed using proposed method is much better than other posicast control method.


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