scholarly journals Online control of combine reel height in presence of farm roughness using an on-off controller

2019 ◽  
Vol 13 (2) ◽  
pp. 104-109
Author(s):  
Nadia Zendehdel ◽  
Younes Shamoradi
Keyword(s):  
Control System ◽  
Laboratory Sample ◽  
Height Control ◽  
Optical Distance ◽  
Normal Probability ◽  
Height Change ◽  
Distance Sensor ◽  
Normal Probability Distribution ◽  
Controllability And Observability ◽  
Excitation Circuit

Adjusting the harvesting combine reel height in presence of the farm rough surface reduces the harvest losses, prevents possible damage to the headland and increases gravel harvest. Regarding the importance of the issue, in this study, the dynamics of the reel height control system of the John Deere1055 combine was modeled and the controllability and observability of the obtained transfer function is determined in state space. After that, with the aim of cutting the stem from a suitable point, an on-off controller is designed to keep the reel height from the ground in a permitted range. At this stage, a reduced model system is used as an approximated system to design a controller. The designed controller is simulated in MATLAB. In this simulation, the roughness of the ground was considered as the control loop noise with the normal probability distribution function. The results confirm that the reel height change is kept in the specified range against the farm roughness. The laboratory sample was also constructed using an independent excitation circuit DC motor, an optical distance sensor, and a micro controller. The experimental test shows that the height control system responses to changes in surface height at an appropriate speed without any oscillation in range.

scholarly journals Can Liquid Lenses Increase Depth of Field in Head Mounted Video See-Through Devices?

2021 ◽  
Vol 7 (8) ◽  
pp. 138
Author(s):  
Marina Carbone ◽  
Davide Domeneghetti ◽  
Fabrizio Cutolo ◽  
Renzo D’Amato ◽  
Emanuele Cigna ◽  
...  
Keyword(s):  
Control System ◽  
Clinical Practice ◽  
Augmented Reality ◽  
Time Of Flight ◽  
Depth Of Field ◽  
Liquid Lenses ◽  
Good Potential ◽  
Distance Sensor ◽  
Limited Depth ◽  
Lens Optics

Wearable Video See-Through (VST) devices for Augmented Reality (AR) and for obtaining a Magnified View are taking hold in the medical and surgical fields. However, these devices are not yet usable in daily clinical practice, due to focusing problems and a limited depth of field. This study investigates the use of liquid-lens optics to create an autofocus system for wearable VST visors. The autofocus system is based on a Time of Flight (TOF) distance sensor and an active autofocus control system. The integrated autofocus system in the wearable VST viewers showed good potential in terms of providing rapid focus at various distances and a magnified view.

scholarly journals A tide prediction and tide height control system for laboratory mesocosms

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1442 ◽  
Author(s):  
Luke P. Miller ◽  
Jeremy D. Long
Keyword(s):  
Control System ◽  
Open Source Software ◽  
Immersion Time ◽  
Field Experiments ◽  
Scale Insect ◽  
Tidal Elevation ◽  
Height Control ◽  
Edaphic Conditions ◽  
Tide Height ◽  
Aquarium Water

Experimental mesocosm studies of rocky shore and estuarine intertidal systems may benefit from the application of natural tide cycles to better replicate variation in immersion time, water depth, and attendant fluctuations in abiotic and edaphic conditions. Here we describe a stand-alone microcontroller tide prediction open-source software program, coupled with a mechanical tidal elevation control system, which allows continuous adjustment of aquarium water depths in synchrony with local tide cycles. We used this system to monitor the growth ofSpartina foliosamarsh cordgrass and scale insect herbivores at three simulated shore elevations in laboratory mesocosms. Plant growth decreased with increasing shore elevation, while scale insect population growth on the plants was not strongly affected by immersion time. This system shows promise for a range of laboratory mesocosm studies where natural tide cycling could impact organism performance or behavior, while the tide prediction system could additionally be utilized in field experiments where treatments need to be applied at certain stages of the tide cycle.

Analysis of a Hydrofoil Craft with a Suspension System

2020 ◽  
Author(s):  
Michel Touw ◽  
Jacob Lotz ◽  
Ido Akkerman
Keyword(s):  
Experimental Data ◽  
Control System ◽  
State Space ◽  
State Space Model ◽  
Suspension System ◽  
Future Research ◽  
Passive System ◽  
Height Control ◽  
Space Model ◽  
Front Wing

In this paper we investigate the efficacy of augmenting, or replacing, an active height control system for a submerged hydrofoil with a passive system based on springs and dampers. A state-space model for submerged hydrofoils is formulated and extended to allow for a suspension at the front wing, aft wing or both wings. The model is partially verified by obtaining results in the fixed-wing limit and comparing these with experimental data from the MARIN Foiling Future Demonstrator. In the current study we limit ourselves to translational springs, only allowing suspension motion in the heave direction. This results in unfavorable behavior: either the motions increased or the system becomes unstable. It is therefore recommended for future research to try rotational springs.

Automatic Header-Height Control System for Windrowers

1974 ◽  
Vol 17 (4) ◽  
pp. 0597-0602
Author(s):  
G. S. Pask ◽  
J. N. Wilson ◽  
G. C. Zoerb
Keyword(s):  
Control System ◽  
Height Control

Reliability Analysis for Link Mechanism under Influence of Multiple Factors Based on Support Vector Machine

2013 ◽  
Vol 753-755 ◽  
pp. 2904-2907 ◽  
Author(s):  
Xue Wei Ke ◽  
Jian Hou ◽  
Ting Feng Chen
Keyword(s):  
Support Vector Machine ◽  
Reliability Analysis ◽  
Support Vector ◽  
Computational Costs ◽  
Link Mechanism ◽  
Normal Probability ◽  
Normal Probability Distribution ◽  
Dimensional Errors ◽  
Multi Body ◽  
External Loads

Considering the influence of dimensional errors,clearances,friction coefficients,external loads and flex of part comprehensively,a multi-body dynamic model of link mechanism is established by using commercial software.Assuming that the above factors follow normal probability distribution are independent with each other,a mechanism reliability analysis method by combining simulation technology and support vector machine (SVM) are proposed to reduce the computational costs. The obtained results show that the computational costs of the proposed methods are much less than the computational costs of Monte Carlo Simulation (MCS).Therefore, the proposed methods might be efficient and valuable for the reliability analysis of complex mechanism.

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