Input shaping algorithm using the s curve velocity command for gantry stage

Cable-suspended robots are categorized as a type of parallel manipulator that has recently attracted interest in terms of manipulation tasks. The main goal of this paper is to develop a novel mechatronic kit with a control methodology for a modularized cable-suspended robot. The advantages of such system owns modular and reconfigurable over conventional robots. In addition, position and orientation of the end-effector is forced toward the desired values by control of cable lengths. Hence, the new approach for forward and inverse kinematic calculation procedure based on the change of the cable lengths is used to measure the position and orientation of the mobile platform. Furthermore, the input shaping algorithm is implemented for point-to-point control purposes. The modified input shaping uses the s curve command (S-type) to offer superior performance than conventional trapezoidal command (T-type) in point-to-point positioning control. Experimental validation demonstrates the cable oscillation suppression effectiveness of the proposed S-type input shaping control command.

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Combined S-curve feedrate profiling and input shaping for glass substrate transfer robot vibration suppression

Industrial Robot the international journal of robotics research and application ◽

10.1108/ir-11-2017-0201 ◽

2018 ◽

Vol 45 (4) ◽

pp. 549-560 ◽

Cited By ~ 4

Author(s):

Chongxu Liu ◽

Youdong Chen

Keyword(s):

Glass Substrate ◽

Vibration Suppression ◽

Settling Time ◽

Input Shaping ◽

Content Type ◽

Acceleration And Deceleration ◽

Increase Productivity ◽

Continuous Input ◽

S Curve ◽

Substrate Transfer

Purpose The glass substrate transfer robot uses flexible arm and fork to transport the glass substrate which will generate vibration. To reduce the settling time and increase productivity, the authors proposed a vibration suppression method that integrated the continuous input shaping into the S-curve feedrate profiling. Design/methodology/approach The quasi-optimal S-curve feedrate profiling is achieved by the robot model. Then the outputs of the S-curve are shaped by the continuous input shaper, which can greatly lower the vibration and shorten the settling time. Findings The robot produces vibrations because of the flexibility of the belt system and the forks; the vibration of the robot is especially obvious in the acceleration and deceleration stage and the low-speed operation stage. Because the fork fingers are flexible, vibration at the end of the fork is enlarged. Originality/value The effectiveness of the proposed method is verified by the comparative experiments conducted on a glass substrate transfer robot.

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Methodology for determining water losses from irrigation canals

Melioration and Water Management ◽

10.32962/0235-2524-2020-5-16-18 ◽

2020 ◽

pp. 16-18

Author(s):

Elena Makarycheva

Keyword(s):

Filtration Rate ◽

Darcy Law ◽

Filtration Flow ◽

Irrigation Canals ◽

Power Functions ◽

Two Phase ◽

Water Losses ◽

Irrigation Channels ◽

Unsteady Filtration ◽

S Curve

The aim of the article is to develop a method for calculating water losses from irrigation channels in determining the permeability of rock in the zone of filtration flow on the basis of the law of infiltration A.N. Kostyakov using the results of studies of free filtration from pits and foundation pits in loess loams. Pressure movement of water in irrigation canals is subject to the laws of two-phase flow, in which – in contrast to the Darcy law for the zone of saturation plays an important role, the volume and its change in time. The filtration rate (VF) increases with increasing rock moisture (θ) along the S-curve, while the pressure gradient (I = dh/dz) decreases. The dependences of these parameters on the pressure are represented by power functions, and their product CDP = VFI does not change in time and can serve as a characteristic of the filtration flow under the channel. When installing paired piezometers near the water chore line in the channel and determining the graph I(t) by the value of the twophase flow constant CDP, it is possible to calculate the filtration rate at a number of times and the water losses during unsteady filtration. Water losses from the channels at equilibrium humidity increases with increasing head according to the formula A.N. Kostyakova, in which the water permeability of rocks is characterized by a steady filtration rate at a head of 1.0 m, and the gradient is the function of pressure. The application of the proposed method of calculating losses in the design of irrigation systems will increase the reliability of the justification of the volume of anti-filtration measures and the forecast of the groundwater level.

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Two Candidate Approaches o Text Sequencing: An Addendum to â€œThe Diachrony Debate: A Tutorial on Methodsâ€

Journal for Semitics ◽

10.25159/1013-8471/3679 ◽

2018 ◽

Vol 26 (2) ◽

Author(s):

Dean A. Forbes

Keyword(s):

Computational Biology ◽

Middle English ◽

Diagnostic Tool ◽

Reliable Method ◽

Biblical Hebrew ◽

Quantitative Comparison ◽

Curve Analysis ◽

Single Feature ◽

S Curve ◽

Temporal Ordering

In a recent essay published in this journal, I illustrated the limitations one may encounter when sequencing texts temporally using s-curve analysis. I also introduced seriation, a more reliable method for temporal ordering much used in both archaeology and computational biology. Lacking independently ordered Biblical Hebrew (BH) data to assess the potential power of seriation in the context of diachronic studies, I used classic Middle English data originally compiled by EllegÃ¥rd. In this addendum, I reintroduce and extend s-curve analysis, applying it to one rather noisy feature of Middle English. My results support Holmstedtâ€™s assertion that s-curve analysis can be a useful diagnostic tool in diachronic studies. Upon quantitative comparison, however, the five-feature seriation results derived in my former paper are found to be seven times more accurate than the single-feature s-curve results presented here.Â

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Curve Estimation Modeling for Predictions of the Novel Coronavirus (Covid-19) Epidemic in Nigeria

Healthy-Mu Journal ◽

10.35747/hmj.v4i1.545 ◽

2020 ◽

Vol 4 (1) ◽

pp. 1

Author(s):

Christian Ebere Enyoh ◽

Andrew Wirnkor Verla ◽

Chidi Edbert Duru ◽

Emmanuel Chinedu Enyoh ◽

Budi Setiawan

Keyword(s):

State Governments ◽

The Novel ◽

Curve Estimation ◽

Exponential Models ◽

Inverse Models ◽

Forward Prediction ◽

S Curve ◽

Novel Coronavirus ◽

Best Fit ◽

Official Data

Based on the official Nigeria Centre for Disease Control (NCDC) data, the current research paper modeled the confirmed cases of the novel coronavirus disease 2019 (COVID-19) in Nigeria. Ten different curve regression models including linear, logarithmic, inverse, quadratic, cubic, compound, power, S-curve, growth, and exponential were used to fit the obtained official data. The cubic (R2 = 0.999) model gave the best fit for the entire country. However, the growth and exponential had the lowest standard error of estimate (0.958) and thus may best be used. The equations for these models were e0.78897+0.0944x and 2.2011e0.0944x respectively. In terms of confirmed cases in individual State, quadratic, cubic, compound, growth, power and exponential models generally best describe the official data for many states except for the state of Kogi which is best fitted with S-curve and inverse models. The error between the model and the official data curve is quite small especially for compound, power, growth and exponential models. The computed models will help to realized forward prediction and backward inference of the epidemic situation in Nigeria, and the relevant analysis help Federal and State governments to make vital decisions on how to manage the lockdown in the country.

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