The agricultural industry has made a tremendous contribution to the foundations of civilization. Basic essentials such as food, beverages, clothes and domestic materials are enriched by the agricultural industry. However, the traditional method in agriculture cultivation is labor-intensive and inadequate to meet the accelerating nature of human demands. This scenario raises the need to explore state-of-the-art crop cultivation and harvesting technologies. In this regard, optics and photonics technologies have proven to be effective solutions. This paper aims to present a comprehensive review of three photonic techniques, namely imaging, spectroscopy and spectral imaging, in a comparative manner for agriculture applications. Essentially, the spectral imaging technique is a robust solution which combines the benefits of both imaging and spectroscopy but faces the risk of underutilization. This review also comprehends the practicality of all three techniques by presenting existing examples in agricultural applications. Furthermore, the potential of these techniques is reviewed and critiqued by looking into agricultural activities involving palm oil, rubber, and agro-food crops. All the possible issues and challenges in implementing the photonic techniques in agriculture are given prominence with a few selective recommendations. The highlighted insights in this review will hopefully lead to an increased effort in the development of photonics applications for the future agricultural industry.

https://www.mdpi.com/1420-3049/24/10/2025/pdf

Applications of Photonics in Agriculture Sector: A Review

Speed Control of PMSM Using Disturbance Observer

Energy storage systems (ESS) are key elements that can be used to improve electrical system efficiency by contributing to balance of supply and demand. They provide a means for enhancing the power quality and stability of electrical systems. They can enhance electrical system flexibility by mitigating supply intermittency, which has recently become problematic, due to the increased penetration of renewable generation. Flywheel energy storage systems (FESS) are a technology in which there is gathering interest due to a number of advantages offered over other storage solutions. These technical qualities attributed to flywheels include high power density, low environmental impact, long operational life, high round-trip efficiency and high cycle life. Furthermore, when configured in banks, they can store MJ levels of energy without any upper limit. Flywheels configured for grid connected operation are systems comprising of a mechanical part, the flywheel rotor, bearings and casings, and the electric drive part, inclusive of motor-generator (MG) and power electronics. This contribution focusses on the modelling and simulation of a high inertia FESS for energy storage applications which has the potential for use in the residential sector in more challenging situations, a subject area in which there are few publications. The type of electrical machine employed is a permanent magnet synchronous motor (PMSM) and this, along with the power electronics drive, is simulated in the MATLAB/Simulink environment. A brief description of the flywheel structure and applications are given as a means of providing context for the electrical modelling and simulation reported. The simulated results show that the system run-down losses are 5% per hour, with overall roundtrip efficiency of 88%. The flywheel speed and energy storage pattern comply with the torque variations, whilst the DC-bus voltage remains constant and stable within ±3% of the rated voltage, regardless of load fluctuations.

Development of a high-fidelity model for an electrically driven energy storage flywheel suitable for small scale residential applications

The fluctuating nature of many renewable energy sources (RES) introduces new challenges in power systems. Flywheel Energy Storage Systems (FESS) in general have a longer life span than normal batteries, very fast response time, and they can provide high power for a short period of time. These characteristics make FESS an excellent option for many applications in future power Microgrids (MGs), in particular with integrated RES. The purpose of this paper is twofold. First, a new topology of FESS in MGs is introduced, where the FESS is connected at the same DC-bus of the fuel cells and the Photovoltaic (PV) inverter instead of connecting it with a separate on-grid inverter. Fuel cells are connected at the bus to help the FESS to operate as Uninterruptible Power Supply (UPS) system for longer periods by using the same power electronics components. Not only this topology is cost-effective, but also it allows higher PV penetration levels due to regulating the power flow by the flywheel and it is also more efficient than the traditional topology due to the shortest path of power flow. Second, a detailed simulation model of MGs with FESS is developed. This simulation model makes it possible to explore different scenarios including connected and isolated status of MGs with high levels of PV penetration. The simulation results demonstrate the ability of FESS to withstand changes in the load, PVs and wind, and the ability to provide electricity even when an interruption from the utility grid occurs. Additionally, the common on-grid inverter has been exploited to compensate the reactive power and hence improve the power factor inside the MG.

/pdf/modeling-control-and-simulation-of-a-new-topology-of-4ti5bf9e7o.pdf

Modeling, Control, and Simulation of a New Topology of Flywheel Energy Storage Systems in Microgrids

On the basis of analysis of dq model of permanent magnet synchronous motor (PMSM) and principle of field oriented control (FOC), detail modelling of PMSM drive system and simulation results presented in this paper. The PMSM model is based on electronic components rather than mathematical blocks, this enabled us to achieve simulation results more realistic.  Moreover all the modules of this simulation, such as inverter and pwm generator are made from scratch instead of using premade Simulink blocks.  Simulation was carried on the basis of step change in speed and torque then made performance comparison of several parameters such as abc current, dq current, speed and torque.

/pdf/modelling-and-simulation-of-field-oriented-control-based-2yd5n89s9y.pdf

Modelling and Simulation of Field Oriented Control based Permanent Magnet Synchronous Motor Drive System

At the basis of analysis of the mathematical model of the permanent-magnet synchronous motor (PMSM) and the principle of field-orientated vector control, a novel method for modeling and simulink of PMSM system based on SVPWM is proposed. In Matlab/simulink, the simulation model of the whole system is built, two control loops are used, which are inner current-loop and the outer speed-loop. By simulating the specific motor, the waveforms are presented, which achieves the expected effect, and the reasonability and validity has been proved.

Simulation of PMSM Vector Control System Based on Matlab/Simulink

As to aided driving by harvesting robot, an algorithm is hereby proposed for walking goal line detection on improved Hough transform (HT) on harvesting robot. A camera is to be fitted on the left top of the combine harvester in order to capture images of farmland scenes in the process of harvesting. The target locations of walking goal line as well as the optimal points in the straight-line direction are to be determined according to different color features of harvested areas, non-harvested areas and areas without farmlands respectively, by virtue of statistic analysis, morphology and digital sieve. The optimal points are selected as the point set, and wherein Improved HT based on a determined point is applied to complete line detection, which is in comparison with the traditional algorithm of HT, saves large storage space and long time computation. Through processing various pictures the algorithm is well proved with respect to its speed, anti-interference and accuracy.

Walking Goal Line Detection Based on Machine Vision on Harvesting Robot

The invention relates to an automatic detection device, in particular to an automatic detection device for detecting an angle of auto-flowing of seeds. The automatic detection device comprises a mechanical section and a singlechip, wherein the mechanical section includes a transmission device, a camera, an experiment flat plate and a rotary encoder; the experiment flat plate and the rotary encoder are respectively connected with the transmission device; the camera is connected with the experiment flat plate; the singlechip is used for controlling the rotation of the transmission device; the camera is used for collecting the area image of seeds on the experiment flat plate; and the singlechip is used for controlling the operation of the camera, collecting the area image signal, calculating the area change, and collecting the signals of the rotary encoder to achieve angle detection. The automatic detection device for automatically detecting the angle of auto-flowing of seeds in an image manner has the advantages of simple structure, low cost and high reliability, and can repeat the experiment process.

Automatic detection device for detecting angle of auto-flowing of seeds

Air-assisted sprayers are widely employed in orchards, but inappropriate spray parameters can lead to large droplet losses, pesticide waste, and environmental pollution. To investigate the factors affecting the droplet loss of an air-assisted sprayer behind canopies, a two-factor, five-level full experiment was conducted in an actual orchard, where the two factors were the power gradient and foliage area volume density (FAVD). In addition, the location of the sampling point was also considered in the data analysis, including horizontal distance, forward distance, and height. The results show that all factors significantly affected droplet coverage (p-value < 0.01). The droplet coverage showed an increase and then a decrease with an increasing power gradient, and the maximum coverage was measured at power gradient P3 (forward speed: 0.49 m/s, spray pressure: 0.30 MPa, and spray flow rate: 7.13 L/min) or P4 (forward speed: 0.58 m/s, spray pressure: 0.35 MPa, and spray flow rate: 8.44 L/min). The effect of FAVD on droplet coverage had obvious regularity, and this regularity did not change with the power gradient. At different positions behind canopies, the droplet coverage had great differences. The droplet coverage gradually decreases with increasing horizontal distance and height, while increasing with forward distance. This study provides a reference for the air-assisted sprayers to reduce droplet loss, and data support for subsequent research on precision spraying based on FAVD.

/pdf/factors-affecting-droplet-loss-behind-canopies-with-air-3tx4exrw.pdf

Yu Tan

Papers

Simulation of PMSM Vector Control System Based on Matlab/Simulink

Walking Goal Line Detection Based on Machine Vision on Harvesting Robot

Automatic detection device for detecting angle of auto-flowing of seeds

Factors Affecting Droplet Loss behind Canopies with Air-Assisted Sprayers Used for Fruit Trees