Design and Control Strategy of a Low-Cost Parallel Robot for Precise Solar Tracking

SUMMARYThis paper presents the design, kinematics, dynamics and control of a low-cost parallel rehabilitation robot developed at the Universitat Politècnica de Valencia. Several position and force controllers have been tested to ensure accurate tracking performances. An orthopedic boot, equipped with a force sensor, has been placed over the platform of the parallel robot to perform exercises for injured ankles. Passive, active-assistive and active-resistive exercises have been implemented to train dorsi/plantar flexion, inversion and eversion ankle movements. In order to implement the controllers, the component-based middleware Orocos has been used with the advantage over other solutions that the whole scheme control can be implemented modularly. These modules are independent and can be configured and reconfigured in both configuration and runtime. This means that no specific knowledge is needed by medical staff, for example, to carry out rehabilitation exercises using this low-cost parallel robot. The integration between Orocos and ROS, with a CAD model displaying the actual position of the rehabilitation robot in real time, makes it possible to develop a teleoperation application. In addition, a teleoperated rehabilitation exercise can be performed by a specialist using a Wiimote (or any other Bluetooth device).

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A simple vision-based navigation and control strategy for autonomous drone racing

10.36227/techrxiv.14452725.v1 ◽

2021 ◽

Author(s):

Artur Cyba ◽

Hubert Szolc ◽

Tomasz Kryjak

Keyword(s):

Control System ◽

Visual Feedback ◽

Control Strategy ◽

Control Strategies ◽

Low Cost ◽

Laptop Computer ◽

Vision Based Navigation ◽

Navigation And Control ◽

Positioning Method ◽

And Control

In this paper, we present a control system that allows a drone to fly autonomously through a series of gates marked with ArUco tags. A simple and low-cost DJI Tello EDU quad-rotor platform was used. Based on the API provided by the manufacturer, we have created a Python application that enables the communication with the drone over WiFi, realises drone positioning based on visual feedback, and generates control. Two control strategies were proposed, compared, and critically analysed. In addition, the accuracy of the positioning method used was measured.<br>The application was evaluated on a laptop computer (about 40 fps) and a Nvidia Jetson TX2 embedded GPU platform (about 25 fps). We provide the developed code on GitHub. <br>

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Diseño e implementación de un sistema seguidor solar inteligente a dos ejes para optimizar la producción de energía fotovoltaica con una lente de fresnel y un sistema de limpieza robotizado a bajo costo

Revista de Energías Renovables ◽

10.35429/jre.2019.11.3.1.6 ◽

2019 ◽

pp. 1-6

Author(s):

José Juan Hernández-Medina ◽

Hilario López-Xelo ◽

José Luis Cabrera-Pérez ◽

Aldo Hernández-Díaz

Keyword(s):

Solar Energy ◽

Tracking System ◽

Low Cost ◽

Cleaning System ◽

Solar Tracking ◽

Low Weight ◽

Fresnel Lenses ◽

And Control ◽

The Impact ◽

Concentrate Solar Energy

Photovoltaic systems with Fresnel lenses are expensive, as well as technologically complex, due to their optical, mechanical and control components. In addition, all these systems are sensitive to operation and maintenance costs. This article proposes the use of commercial Fresnel lenses to improve the efficiency of photovoltaic modules, in conjunction with a fuzzy intelligent controlled solar tracking system with two-axis and a novel low-cost robotic cleaning system. The basic idea is that this system optimizes the production of electricity in an economically and technologically simple way. The technology of Arduino microcontrollers and fuzzy logic for control, as well as the geometry of Fresnel lenses, will be used to concentrate solar energy in a small area, not to mention that these optical devices have a low weight. The accumulated effect of energy production will be improved by a novel low cost robotic cleaning system. The alignment and perpendicularity of the impact of solar energy on photovoltaic cells must be maintained as much as possible and the performance of this system must be compared with other more expensive and technologically more complex commercial systems.

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Design PV Tracking System According to Efficiency in Function of Orientation

10.20944/preprints201805.0228.v1 ◽

2018 ◽

Cited By ~ 1

Author(s):

José Ruelas ◽

Benjamin Pusch ◽

Flavio Muños ◽

Juan Delfin ◽

Francisco Javier Ochoa Estrella

Keyword(s):

Design Methodology ◽

Collection Efficiency ◽

Tracking System ◽

Low Cost ◽

High Availability ◽

Solar Tracking ◽

Starting Point ◽

Solar Tracker ◽

Available Technology ◽

And Control

This article proposes a new photovoltaic (PV) solar tracker design based on the advantage that installation latitude offers according to efficiency in function of orientation (EFO) of PVs. First, is described a methodology to let incorporate a low-precision, low-cost and high-availability solar tracking mechanism and control system. The design methodology considers the installation location (latitude and azimuth) as a starting point for establishing an adequate angular range of EFO, simultaneity the aspects of available technology and the knowledge accords to developer. Finally, the design technique is experimentally validated by the implementation of a solar tracker at latitude of 28° longitude of 109° and evaluates the efficiency on a specific day. According to result the feasibility of this type of solar tracker for latitudes close to or greater than 30° is highlighted, given that this tracking system costs 30% less than traditional commercial systems as slew drive with its incorporation of lower-resolution azimuth tracking mechanisms. It also increases collection efficiency by 26%, just as continuous or time-based dual-axis solar trackers do, without the more complex controls and mechanisms of these designs.

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On the Design of a 4 Degrees-of-freedom Pick and Place Cable Suspended Parallel Manipulator

IAES International Journal of Robotics and Automation (IJRA) ◽

10.11591/ijra.v6i4.pp286-302 ◽

2017 ◽

Vol 6 (4) ◽

pp. 286

Author(s):

F. J. Castillo-Garcia ◽

P. Rea ◽

A. Gonzalez-Rodriguez ◽

E. Ottaviano

Keyword(s):

Control Strategy ◽

Parallel Manipulator ◽

Degrees Of Freedom ◽

Parallel Robot ◽

Medium Size ◽

Pd Controller ◽

Positioning Accuracy ◽

Pick And Place ◽

And Control ◽

4 Degrees Of Freedom

This paper proposes the design and control strategy for a four degrees-of-freedom spatial cable-suspended parallel robot for pick and place operations. Pick and place is a repetitive task requiring payload changes for the movement to pick-up the object, and the movement to the nal pose to release the manipulated object. In this paper, a new robust control strategy has been proposed, together with proper trajectories for the required operation. The control strategy consists on the system decoupling and linearization by means of a feedforward term and a cascade PD controller. The main advantage of the proposed solution is that its design can be scalable in size spanning from centimeters to meters with a relatively good positioning accuracy. Finally, simulations are reported to show the overall performances of the proposed con guration for pick and place operations with a medium size manipulator.

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A simple vision-based navigation and control strategy for autonomous drone racing

10.36227/techrxiv.14452725 ◽

2021 ◽

Author(s):

Artur Cyba ◽

Hubert Szolc ◽

Tomasz Kryjak

Keyword(s):

Control System ◽

Visual Feedback ◽

Control Strategy ◽

Control Strategies ◽

Low Cost ◽

Laptop Computer ◽

Vision Based Navigation ◽

Navigation And Control ◽

Positioning Method ◽

And Control

In this paper, we present a control system that allows a drone to fly autonomously through a series of gates marked with ArUco tags. A simple and low-cost DJI Tello EDU quad-rotor platform was used. Based on the API provided by the manufacturer, we have created a Python application that enables the communication with the drone over WiFi, realises drone positioning based on visual feedback, and generates control. Two control strategies were proposed, compared, and critically analysed. In addition, the accuracy of the positioning method used was measured.<br>The application was evaluated on a laptop computer (about 40 fps) and a Nvidia Jetson TX2 embedded GPU platform (about 25 fps). We provide the developed code on GitHub. <br>

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Genotype analysis, source tracing and control strategy of an outbreak of carbapenem-resistant Acinetobacter Baumannii in a NICU

Klinische Pädiatrie ◽

10.1055/s-0030-1261471 ◽

2010 ◽

Vol 222 (S 01) ◽

Author(s):

Z Hu ◽

Y Shi

Keyword(s):

Acinetobacter Baumannii ◽

Control Strategy ◽

Genotype Analysis ◽

Carbapenem Resistant ◽

Source Tracing ◽

And Control

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A Novel Data Utilization and Control Strategy for Wireless Structural Control Systems with TDMA Network

Computing in Civil Engineering ◽

10.1061/9780784413029.005 ◽

2013 ◽

Cited By ~ 4

Author(s):

Z. Sun ◽

B. Li ◽

S. J. Dyke ◽

C. Lu

Keyword(s):

Control Systems ◽

Control Strategy ◽

Structural Control ◽

Data Utilization ◽

And Control

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Dry chip feedrate control using online chip moisture

TAPPI Journal ◽

10.32964/tj17.05.295 ◽

2018 ◽

Vol 17 (05) ◽

pp. 295-305

Author(s):

Wesley Gilbert ◽

Ivan Trush ◽

Bruce Allison ◽

Randy Reimer ◽

Howard Mason

Keyword(s):

Production Rate ◽

Control Strategy ◽

Rate Control ◽

Near Infrared ◽

Dry Mass ◽

The Other ◽

Process Variability ◽

Moisture Sensor ◽

Feedback Control Strategy ◽

And Control

Normal practice in continuous digester operation is to set the production rate through the chip meter speed. This speed is seldom, if ever, adjusted except to change production, and most of the other digester inputs are ratioed to it. The inherent assumption is that constant chip meter speed equates to constant dry mass flow of chips. This is seldom, if ever, true. As a result, the actual production rate, effective alkali (EA)-to-wood and liquor-to-wood ratios may vary substantially from assumed values. This increases process variability and decreases profits. In this report, a new continuous digester production rate control strategy is developed that addresses this shortcoming. A new noncontacting near infrared–based chip moisture sensor is combined with the existing weightometer signal to estimate the actual dry chip mass feedrate entering the digester. The estimated feedrate is then used to implement a novel feedback control strategy that adjusts the chip meter speed to maintain the dry chip feedrate at the target value. The report details the results of applying the new measurements and control strategy to a dual vessel continuous digester.

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