<i>Field Performance Evaluation of Pulse-Width Modulation (PWM) and Pressure-Controlled (PC) Systems for Sensor-Based Nitrogen Applications</i>

2020 ◽  
Author(s):  
Jackson S Stansell ◽  
Samantha L Teten ◽  
Samuel E Marx ◽  
Joe D Luck
Keyword(s):  
Performance Evaluation ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Field Performance ◽  
Pressure Controlled

Field Performance Evaluation of Pulse-Width Modulation and Pressure-Controlled, Fixed-Orifice Application Systems for Sensor-Based Nitrogen Applications

2021 ◽  
Vol 37 (3) ◽  
pp. 467-480
Author(s):  
Jackson S Stansell ◽  
Samantha L Teten ◽  
Samuel E Marx ◽  
Joe D Luck
Keyword(s):  
Precision Agriculture ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Field Performance ◽  
List Type ◽  
Technological Advancement ◽  
N Application ◽  
Application Systems ◽  
Operational Variables ◽  
Pressure Controlled

HighlightsComparison of PC system and PWM system in-field performance indicated that the PWM system made sensor-based N applications more accurately than the PC system.The turndown ratio calculated from the aggregate application instances was 6.2:1.For both the PWM system and the PC system, applications were made more accurately when 28% UAN was applied rather than 32% UAN. Abstract. Sensor-based nitrogen (N) applications have shown promise for improving N use efficiency, but present significant challenges for application rate control due to highly variable and frequently changing target rates. If applications are to be made precisely, equipment systems used for sensor-based N applications must be designed to meet system demands. Pulse-width modulation (PWM) equipped systems have emerged as a technological advancement over traditional pressure-controlled (PC) systems for improving variable rate N application accuracy. Little research, however, has been done to assess the performance of PWM systems during sensor-based N applications in-field. This work analyzed as-applied data collected from in-field sensor-based N applications with pressure-controlled (PC) and PWM systems in Nebraska between 2015 and 2017 to quantify system requirements, assess system performance, and determine performance impacting operational variables. It was found that systems should be capable of 1-s rate changes of ±71.1 L ha-1 (7.6 gpa), 1-s flow rate changes of ±11.4 L min-1 (3 gpm), and turndown ratios of at least 6:1. PWM systems achieved application rates within 10% of the target rate 10% more often than PC systems, and showed less variability in application error. However, PWM systems still demonstrated significant application errors with an observed RMSE of 44.9 L ha-1 (4.8 gpa). Speed change magnitude was found to be most associated with increases in percent application error. These findings substantiate that PWM systems effectively improve sensor-based N application accuracy versus traditional PC systems. However, collaborative efforts toward greater cohesion between sensor-based application expectations and application equipment capabilities are necessary for maximizing the effectiveness of sensor-based N applications. Keywords: Precision agriculture, Rate controllers, Site-specific crop management, Sprayer, Turndown ratio.

Performance Evaluation of Precoded Pulse Width Modulation for Image Sensor Communication

2018 ◽  
Author(s):  
Satoshi Kamegawa ◽  
Masayuki Kinoshita ◽  
Takaya Yamazato ◽  
Hiraku Okada ◽  
Toshiaki Fujii ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Image Sensor

Performance evaluation of carrier rotation strategy in level‐shifted pulse‐width modulation technique

2014 ◽  
Vol 7 (3) ◽  
pp. 667-680 ◽  
Author(s):  
Dharmavarapu Sreenivasarao ◽  
Pramod Agarwal ◽  
Biswarup Das
Keyword(s):  
Performance Evaluation ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Modulation Technique ◽  
Rotation Strategy

Analysis of Crankcase Flow of an Automobile ECV for Air Conditioning Control System

2013 ◽  
Vol 373-375 ◽  
pp. 421-426 ◽  
Author(s):  
Md. Iqbal Mahmud ◽  
Haeng Muk Cho
Keyword(s):  
Control System ◽  
Experimental Test ◽  
Input Signal ◽  
Pulse Width ◽  
Air Conditioning ◽  
Pulse Width Modulation ◽  
Control Valve ◽  
Electromagnetic Control ◽  
Pressure Controlled ◽  
Conditioning Control

Electromagnetic control valve (ECV) controls an automobile vehicle air conditioning compressor based on a pulse width modulation (PWM) input signal that supplied from an external controller. For maintaining a suitable range of temperatures inside the vehicle, suction and crankcase port pressure controls the swash (wobble) plate at certain angle. Suction and crankcase port pressure controlled in ECV can be analyzed by experimental test by considering different technical assumptions. This research paper highlights the flow of air from crankcase port with correspondence with amount of variable supply of current to obtain the experimental test data which is important to maintain the vehicle temperature inside the compartment for passengers comfort.

The 1-Bit Instrument

2020 ◽  
Vol 1 (1) ◽  
pp. 44-74
Author(s):  
Blake Troise
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Interleaving Techniques ◽  
Sonic Environment

The 1-bit sonic environment (perhaps most famously musically employed on the ZX Spectrum) is defined by extreme limitation. Yet, belying these restrictions, there is a surprisingly expressive instrumental versatility. This article explores the theory behind the primary, idiosyncratically 1-bit techniques available to the composer-programmer, those that are essential when designing “instruments” in 1-bit environments. These techniques include pulse width modulation for timbral manipulation and means of generating virtual polyphony in software, such as the pin pulse and pulse interleaving techniques. These methodologies are considered in respect to their compositional implications and instrumental applications.

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