scholarly journals Comparison of a Lightweight Experimental Shaker and an Orchard Tractor Mounted Trunk Shaker for Fresh Market Citrus Harvesting

Agriculture ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1092
Author(s):  
Coral Ortiz ◽  
Antonio Torregrosa ◽  
Sergio Castro-García
Keyword(s):  
Removal Efficiency ◽  
High Speed ◽  
Experimental Device ◽  
High Speed Camera ◽  
Time Increase ◽  
Fresh Market ◽  
Harvesting Systems ◽  
Vibration Time ◽  
Vibration Parameters ◽  
Citrus Harvesting

A designed lightweight experimental shaker successfully used to collect ornamental oranges has been tested to harvest fresh market citrus. The aim of this study was to evaluate the removal efficiency and operational times of this experimental device compared to an orchard trunk shaker. Three different collecting systems were studied. ‘Caracara’ citrus trees were tested. Removal efficiency, vibration parameters, fruit and tree damages, and fruit quality were measured. A high-speed camera was used to record operational times and determine cumulative removal percentage over vibration time. The canvases on the ground reduced the severe fruit damages but were not useful to protect against light damages. The experimental shaker produced a higher percentage of slightly damaged oranges. No significant differences in removal efficiency were found between the two harvesting systems. However, removal efficiency using the experimental device could be reduced by 40 percent and working time increase by more than 50 percent when access to the main branches was difficult. In agreement with previous results, the curve representing the branch cumulative removal percentage in time followed a sigmoidal pattern. A model was built showing that during the first 5 s more than 50 percent of the fruits were detached.

Development of a test method and experimental study on cable unwinding

2020 ◽  
pp. 095440622095449
Author(s):  
Ji-Heon Kang ◽  
Kun-Woo Kim ◽  
Jae-Wook Lee ◽  
Yong-Jae Cho ◽  
Jin-Seok Jang
Keyword(s):  
Experimental Study ◽  
Textile Industry ◽  
High Speed ◽  
Translational Motion ◽  
Control Device ◽  
Test Method ◽  
Experimental Device ◽  
High Speed Camera

In addition to the textile industry, unwinding of cable or fiber is used in various fields such as electronics, communication, and guided weapons. The cable released from the package exhibit a complicated behavior, entailing a combination of rotational and translational motion. This causes problems such as entangling and fracture. Therefore, it is necessary to study boundary and adhesion conditions to prevent unwinding failure. In this study, an experimental device for the analysis of cable unwinding was developed, and unwinding behavior was analyzed experimentally under various unwinding conditions. The experimental device comprises a jig for high-speed camera measurements, control device, and cable unwinding device. Cable behavior was analyzed according to the unwinding velocity and the distance between the fiber package and the point where the fiber was released. In addition, unwinding behavior with respect of the tension acting on the cable was analyzed experimentally by applying the adhesive.

scholarly journals Study on Mechanical Law of Vibration Abscission of Camellia Oleifera Fruit Based on High-Speed Camera Technology

2019 ◽  
Vol 10 ◽  
pp. 1713-1725
Author(s):  
Yang Cheng ◽  
Wang Qi
Keyword(s):  
High Speed ◽  
Mechanical Characteristics ◽  
Vibration Source ◽  
High Speed Camera ◽  
Camellia Oleifera ◽  
Binding Force ◽  
Harvesting Process ◽  
Pulling Force ◽  
Vibration Parameters ◽  
Low Amplitude

The movement and mechanical characteristics of oil-tea camellia fruit coupling with flower simultaneously during the harvest period were studied to provide an indispensable theoretical guideline for the mechanized picking machine. The mechanical properties of Camellia oleifera were obtained by investigating its flowers and fruits, and the vibration harvesting of Camellia oleifera was studied by using dynamic vibration device. The i-Speed3 high-speed camera was used to record the harvesting process, and the image analysis and calculation were carried out by its own Control-Pro software. The results showed that different varieties of Camellia oleifera had different flowering periods, ranging from 30 to 55 days; their weight also varied among varieties; there was no inevitable relationship between the binding force (pulling force and torque) of fruit stalks and their varieties, locations and diameter of fruit stalks. More importantly, during the vibration process, the fruit peeling speed is related to the vibration source clamping position and vibration parameters. Under the condition of short clamping distance and high frequency and low amplitude, the fruit is more likely to fall off.

scholarly journals Experimental Motion Analysis of Radially Rotating Beams Using High-Speed Camera and Motion Analyzer

1996 ◽  
Vol 3 (4) ◽  
pp. 293-301
Author(s):  
K.H. Low ◽  
Michael W.S. Lau ◽  
K.K. Low
Keyword(s):  
Strain Measurement ◽  
Vibration Analysis ◽  
High Speed ◽  
Reference Points ◽  
The Other ◽  
Strain Gauges ◽  
High Speed Camera ◽  
Flexible Beams ◽  
Vibrating Beams ◽  
Vibration Parameters

Although strain gauges can be attached to a system for vibration analysis, wires connected to the strain gauges may disturb the system and affect the accuracy of the strain measurement. As an alternative, this work presents the use of a high-speed camera combined with a motion analyzer to study the motion of rotating flexible beams. One end of the beam is rigidly connected to a motor, while the other end is free. White stickers placed on selected points on a given beam are the reference points in a digitization process. The modes of the vibrating beams can be filmed and analyzed. The vibration parameters, such as deflection and frequency, can be obtained by using a film motion analyzer. The results show that the beam does not behave in a clamped-free or a pinned-free fashion, but instead occurs at an intermediate boundary between these two classical conditions.

Field Evaluation of Targeted Shake-and-Catch Harvesting Technologies for Fresh Market Apple

2020 ◽  
Vol 63 (6) ◽  
pp. 1759-1771
Author(s):  
Xin Zhang ◽  
Long He ◽  
Manoj Karkee ◽  
Matthew David Whiting ◽  
Qin Zhang
Keyword(s):  
Removal Efficiency ◽  
Fruit Quality ◽  
Washington State ◽  
Automated System ◽  
List Type ◽  
Agricultural Crop ◽  
Continuous Linear ◽  
Fresh Market ◽  
Fruit Removal ◽  
Harvesting Systems

HighlightsThree shaking methods and vibratory harvesting systems were evaluated and compared.Multi-year field evaluations were performed with up to six cultivars trained to formal architectures.The updated semi-automated system achieved the highest fruit removal efficiency and the best fruit quality.Abstract. Apple is the most economically important agricultural crop in Washington State. In 2018, Washington State produced ~3.3 billion kg of apple, accounting for approximately 63% of U.S. production. Fresh-market apple is currently harvested manually, requiring large numbers seasonal semi-skilled workers for a small harvest window. To overcome the increasing challenges of uncertain labor availability and raising labor costs, a promising mechanical harvesting system, using a targeted shake-and-catch approach, is under development at Washington State University. This study evaluated the system by analyzing its fruit harvest efficiency and fruit quality with three shaking methods, i.e., continuous non-linear, continuous linear, and intermittent linear shaking, on up to six apple cultivars trained to formal tree architectures. Results showed that intermittent linear shaking achieved 90% fruit removal efficiency for ‘Scifresh’ cultivar, while continuous linear shaking achieved only 63% removal efficiency for ‘Gala’. This study also compared three vibratory systems: a hand-held system, a hydraulically driven system, and a semi-automated hydraulic system. The semi-automated system achieved the highest fruit removal efficiency (90%), followed by the hand-held (87%) and hydraulic (84%) systems, mainly due to the different shaking methods employed. However, the differences were statistically insignificant. Fruit catching efficiency varied among the harvesting systems, with the hand-held system achieving the highest efficiency (97%), followed by the hydraulic (91%) and semi-automated (88%) systems. Among the three tested technologies, the prototype semi-automated system achieved the highest level of mechanization, as well as high fruit removal efficiency and the best fruit quality. Because the semi-automated system did not include an auto-positioning function, positioning its shaker head took about eight times longer (~103 s) than the actual shaking time (~13 s), which suggests that a fully automated system is desirable to further increase productivity. This study showed that the shake-and-catch approach has great potential for practical adoption in harvesting of fresh-market apple and therefore can have a positive economic impact on the U.S. apple industry. Keywords: Automation in apple production, Bulk mechanical harvest, Semi-automated system, Shaking method, Time efficiency.

scholarly journals Tracking by Deblatting

2021 ◽  
Author(s):  
Denys Rozumnyi ◽  
Jan Kotera ◽  
Filip Šroubek ◽  
Jiří Matas
Keyword(s):  
High Speed ◽  
High Performance ◽  
Motion Blur ◽  
Velocity Estimation ◽  
High Speed Camera ◽  
Trajectory Function ◽  
Novel Approach ◽  
Blind Deblurring ◽  
Object Trajectories ◽  
Complex Trajectories

AbstractObjects moving at high speed along complex trajectories often appear in videos, especially videos of sports. Such objects travel a considerable distance during exposure time of a single frame, and therefore, their position in the frame is not well defined. They appear as semi-transparent streaks due to the motion blur and cannot be reliably tracked by general trackers. We propose a novel approach called Tracking by Deblatting based on the observation that motion blur is directly related to the intra-frame trajectory of an object. Blur is estimated by solving two intertwined inverse problems, blind deblurring and image matting, which we call deblatting. By postprocessing, non-causal Tracking by Deblatting estimates continuous, complete, and accurate object trajectories for the whole sequence. Tracked objects are precisely localized with higher temporal resolution than by conventional trackers. Energy minimization by dynamic programming is used to detect abrupt changes of motion, called bounces. High-order polynomials are then fitted to smooth trajectory segments between bounces. The output is a continuous trajectory function that assigns location for every real-valued time stamp from zero to the number of frames. The proposed algorithm was evaluated on a newly created dataset of videos from a high-speed camera using a novel Trajectory-IoU metric that generalizes the traditional Intersection over Union and measures the accuracy of the intra-frame trajectory. The proposed method outperforms the baselines both in recall and trajectory accuracy. Additionally, we show that from the trajectory function precise physical calculations are possible, such as radius, gravity, and sub-frame object velocity. Velocity estimation is compared to the high-speed camera measurements and radars. Results show high performance of the proposed method in terms of Trajectory-IoU, recall, and velocity estimation.

Influence of Main Swirler Vane Angle on the Ignition Performance of TeLESS-II Combustor

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Bo Wang ◽  
Chi Zhang ◽  
Yuzhen Lin ◽  
Xin Hui ◽  
Jibao Li
Keyword(s):  
High Speed ◽  
Inlet Temperature ◽  
Main Stage ◽  
Ignition Process ◽  
High Speed Camera ◽  
Fuel Distribution ◽  
Fuel Droplets ◽  
Planar Laser ◽  
Cfd Method ◽  
Vane Angle

In order to balance the low emission and wide stabilization for lean premixed prevaporized (LPP) combustion, the centrally staged layout is preferred in advanced aero-engine combustors. However, compared with the conventional combustor, it is more difficult for the centrally staged combustor to light up as the main stage air layer will prevent the pilot fuel droplets arriving at igniter tip. The goal of the present paper is to study the effect of the main stage air on the ignition of the centrally staged combustor. Two cases of the main swirler vane angle of the TeLESS-II combustor, 20 deg and 30 deg are researched. The ignition results at room inlet temperature and pressure show that the ignition performance of the 30 deg vane angle case is better than that of the 20 deg vane angle case. High-speed camera, planar laser induced fluorescence (PLIF), and computational fluids dynamics (CFD) are used to better understand the ignition results. The high-speed camera has recorded the ignition process, indicated that an initial kernel forms just adjacent the liner wall after the igniter is turned on, the kernel propagates along the radial direction to the combustor center and begins to grow into a big flame, and then it spreads to the exit of the pilot stage, and eventually stabilizes the flame. CFD of the cold flow field coupled with spray field is conducted. A verification of the CFD method has been applied with PLIF measurement, and the simulation results can qualitatively represent the experimental data in terms of fuel distribution. The CFD results show that the radial dimensions of the primary recirculation zone of the two cases are very similar, and the dominant cause of the different ignition results is the vapor distribution of the fuel. The concentration of kerosene vapor of the 30 deg vane angle case is much larger than that of the 20 deg vane angle case close to the igniter tip and along the propagation route of the kernel, therefore, the 30 deg vane angle case has a better ignition performance. For the consideration of the ignition performance, a larger main swirler vane angle of 30 deg is suggested for the better fuel distribution when designing a centrally staged combustor.

scholarly journals Leader-chasing behavior in negative artificial triggered lightning flashes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fukun Wang ◽  
Jianguo Wang ◽  
Li Cai ◽  
Rui Su ◽  
Wenhan Ding ◽  
...  
Keyword(s):  
High Speed ◽  
The Other ◽  
Lightning Flash ◽  
High Speed Camera ◽  
Return Stroke ◽  
Catching Up ◽  
Special Cases ◽  
Triggered Lightning

AbstractTwo special cases of dart leader propagation were observed by the high-speed camera in the leader/return stroke sequences of a classical triggered lightning flash and an altitude-triggered lightning flash, respectively. Different from most of the subsequent return strokes preceded by only one leader, the return stroke in each case was preceded by two leaders occurring successively and competing in the same channel, which herein is named leader-chasing behavior. In one case, the polarity of the latter leader was opposite to that of the former leader and these two combined together to form a new leader, which shared the same polarity with the former leader. In the other case, the latter leader shared the same polarity with the former leader and disappeared after catching up with the former leader. The propagation of the former leader in this case seems not to be significantly influenced by the existence of the latter leader.

Sign in / Sign up

Export Citation Format

Share Document