Obtaining the effective gripper dimensions for a kiwifruit harvesting robot using kinematic calibration procedures

Purpose A harvesting robot is developed as part of kiwifruit industry automation in New Zealand. This kiwifruit harvester is currently not economically viable, as it drops and damages too many kiwifruit in the harvesting task due to the positional inaccuracy of the gripper. This is due to the difficulties in measuring the exact effective dimensions of the gripper from the manipulator. The purpose of this study is to obtain the effective gripper dimensions using kinematic calibration procedures. Design/methodology/approach A setup of a constraint plate with a dial gauge is proposed to acquire the calibration data. The constraint plate is positioned above the robot. The data is obtained by using a dial gauge and a permanent marker. The effective dimensions of the gripper are used as error parameters in the calibration process. Calibration is exercised by minimizing the difference between target positions and measured positions iteratively. Findings The robot with the obtained effective dimensions is tested in the field. It is found that the fruit drops due to positional inaccuracy of the gripper are greatly reduced after calibration. Practical implications The kiwifruit industry in New Zealand is growing rapidly and announced plans in 2017 to double global sales by 2025. This growth will put extra pressure on the labour supply for harvesting. Furthermore, the Covid pandemic and resulting border restrictions have dramatically reduced seasonal imported labour availability. A robotic system is a potential solution to address the labour shortages for harvesting kiwifruit. Originality/value For kiwifruit harvesting, the picking envelope is well above the robot; the experimental data points obtained by placing a constraint plate above the robot are at similar positions to the target positions of kiwifruit. Using this set of data points for calibration yields a good effect of obtaining the effective dimension of the gripper, which reduces the positional inaccuracy as shown in the field test results.

Automatic Reading Algorithm of Substation Dial Gauges Based on Coordinate Positioning

With the development of science and technology, inspection robots have attracted more and more attention, and research on the automatic reading of pointer instruments through inspection robots has become particularly valuable. Aiming at the problems of uneven illumination, complex dial background and damping fluid interference of the collected instrument images, this paper proposes a dial gauge reading algorithm based on coordinate positioning. First, the multi-scale retinex with color restoration (MSRCR) is applied to improve the uneven illumination of the image. Second, a circle detection algorithm based on the arc-support line segment is proposed to detect the disc to obtain the coordinate of the center and radius of the circle. Then, a pointerless template is used to obtain the pointer, and the concentric circle algorithm is applied to locate the refined pointer. Finally, the automatic reading is calculated using the relative position of the pointer and the zero scale. The experimental results prove that the proposed algorithm can accurately locate the center of the circle and the pointer and obtain readings automatically.

Laser scanning based straightness measurement of precision bright steel rods

In industrial manufacturing of bright steel rods one important quality factor is the straightness or straightness deviation. Depending on the application, deviations of less than 0.1 mm per meter rod length are desired and can be reached with state of the art manufacturing equipment. Such high quality requirements can only be guaranteed with continuos quality control. Manual straightness measurements conducted offline using a dial gauge provide accurate results on single positions of the rod. We propose a contactless, optical measurment technique based on laser scanning which has the potential to be used inline during production to inspect all rods over the entire length. The method is based on evaluating the intensity signal of the reflected laser radiation against the scan angle. It is shown, that in combination with an accurate calibration this signal can be used to determine the rod’s deviation from a straight rod. We explain the measurement and calibration principle as well as data evaluation. We present the experimental setup and first measurement results on a single position on several samples. For a homogeneous sample surface and neglecting laser drift, accuracy and precision were determined to be in the range of 10 - 20 µm. We discuss the working principle of a potential inline system.

PENGARUH VARIASI MUTU JAKET BETON DAN PENAMBAHAN TULANGAN LATERAL TERHADAP KAPASITAS AKSIAL KOLOM BUJUR SANGKAR

Many researches have been carried out regarding concrete jacketing, such as the addition of stirrup reinforcement and enlargement of dimensions with the quality of the concrete jacket that is equal or exceeds the quality of the core column concrete. To determine the effect of concrete jacket quality and the addition of stirrup reinforcement to the axial column capacity, in this study, the core column (K25) with 25 MPa quality and the quality of the concrete jacket varied 20 MPa, 25 MPa, 30 MPa, with the addition of stirrup reinforcement (KJs column) and without the addition of stirrup reinforcement (KJ column) in each variation of the quality of concrete jackets. It made 3 colomn for each type of treatment. The core column has a square shape with dimensions 80 x 80 x 320 mm and a concrete reinforcement jacket is given with dimensions 160 x 160 x 300 mm. The column is given concentric axial load and the shortening is calculated using a dial gauge for every 20 kN load. The results of this study indicate the addition of jacket and stirrup reinforcement concrete can increase axial capacity and column ductility. As for the increase in axial capacity that occurs in the KJ20, KJ25, KJ30 column, the K25 column is respectively 17.4%; 34.0%; 34.7%. While the axial capacity increase in the KJs20, KJs25, KJs30 columns, for the K25 column is 54.9%; 62.5%; 71.5%. The reinforcement column with the addition of stirrup reinforcement, has a shorter value and greater axial capacity than the core column and reinforcement column without accompanying the addition of stirrups. The increase in axial capacity that occurs also increases along with the increase in the concrete compressive strength of the jacket which is used as reinforcement. Keywords: quality variation, axial capacity, concrete jacketing.

Experimental Study on Investigating the Influence of Combination Combining Eccentricity with Different Orientations for Process System of Milling Center

There are several critical factors which have adverse effects on the workpiece surface finish, dimensional accuracy, tool life, etc. Eccentricity is one of them which can be manipulated when the spindle, tool holder and milling cutter revolve around the line parallel to their cutting axes and crop up due to clamping deviation and geometric imperfections. This work was driven by the observation that there should an approach through which final eccentric error can be reduced as other researchers only displayed the effects of eccentricity on cutting forces, etc. This task was carried out through performing numerous experiments on the CNC milling center and measuring geometric imperfections from the whole body of machining elements at different orientations with dial gauge to find out whether different orientations of elements have effects on the eccentricity. If they have noticeable effects then such orientations of elements exhibiting the minimum eccentricity can be selected which in turn may improve the accuracy and precision of workpieces and reduce the final cutting edge error. Our observation showed that orientations have remarkable effects on the eccentricity pretending lowest final eccentric error which is unable to be ignored.

KAPASITAS GESER BALOK BETON BERTULANG HVFA MEMADAT SENDIRI DENGAN KADAR FLY ASH 50% TERHADAP BETON NORMAL

<p>Penggunaan material alternatif pengganti semen sebagai penyusun beton semakin banyak ditemukan. Salah satunya adalah <em>fly ash</em>. <em>Fly ash</em> adalah sisa pembakaran batubara berupa partikel halus yang mengandung banyak <em>silica</em> (SiO2). Kandungan <em>silica</em> sangat cocok untuk reaksi kimia pembentukan beton. Pada penelitian ini, kadar kandungan semen akan diganti dengan <em>fly ash</em> sebanyak 50% pada pembuatan balok beton bertulang baja <em>high volume fly ash self compacting concrete</em> (HVFA-SCC) dan dibandingkan dengan beton normal. Balok uji berukuran 10 cm x 15 cm dengan panjang 150 cm. Pengujian yang dilakukan adalah uji kapasitas geser pada umur 28 hari dengan menggunakan alat uji <em>loading frame</em> dan memasang <em>dial gauge</em> di titik tengah bentang dan titik pembebanan pada 1/3 panjang balok. Hasil dari pengujian ini adalah nilai beban dan lendutan yang dapat diterima hingga mengalami keruntuhan geser. Berdasarkan penelitian ini, nilai kapasitas geser HVFA-SCC lebih besar dibandingkan beton normal, yaitu sebesar 32,125 kN untuk HVFA-SCC dan sebesar 20,500 kN untuk beton normal.</p><p><strong> </strong></p>

KAJIAN MODULUS ELASTISITAS PADA BETON RINGAN MEMADAT MANDIRI MENGGUNAKAN AGREGAT KASAR PECAHAN GENTENG DENGAN VARIASI VISCOCRETE

<p>Beton kini telah mengalami perkembangan pesat dikarenakan beton merupakan salah satu bahan dasar dalam konstruksi bangunan, terbukti dengan beberapa inovasi jenis beton yang ada di Indonesia salah satunya adalah beton ringan memadat mandiri. Beton ringan memadat mandiri (<em>Lightweight Self Compacting Concrete)</em> adalah beton yang mudah mengalir karena berat sendiri mengisi keseluruhan cetakan sehingga tidak diperlukan <em>vibrator</em> untuk pemadatan dan mempunyai berat jenis tidak lebih dari 2000 kg/m³, karena pada dasarnya beton ringan diperoleh dengan cara penambahan pori-pori ke dalam campuran beton. Pecahan genteng dapat digunakan sebagai agregat ringan karena genteng terbuat dari tanah liat yang dibakar.</p><p>Metode yang digunakan dalam penelitian adalah eksperimental dengan parameter yang dikaji adalah modulus elastisitas beton. Benda uji yang digunakan silinder dengan ukuran diameter 150 mm dan tinggi 300 mm berjumlah 12 dengan melakukan pembacaan <em>dial gauge</em> setiap diberikan beban 20kN. Pada penelitian ini <em>Superplasticizer </em>yang digunakan adalah <em>Viscocrete</em> 8050SG dengan kadar <em>viscocrete</em> 1,5% ; 1,75% ; 2% ; 2,25%.</p><p>Didapatkan hasil modulus elastisitas maksimum menurut ASTM C469 dan Eurocode 2-1992 pada prosentasi <em>viscocrete</em> 2,25% sebesar 17423,37 MPa dan 16425,41 MPa.</p>

Influencing Greater Adoption of Eco-Driving Practices Using an Associative Graphical Display

Substantial energy savings during the use phase of internal combustion and electric automobiles can be achieved by increasing eco-driving behavior, particularly reduced acceleration and braking. However, motivating widespread adoption of this behavior is challenging due to incompatibility with drivers’ values and priorities, and disassociation between drivers’ actions and observable consequences. Informational approaches, e.g., training programs and educational campaigns, are either difficult to scale up or largely ineffective, with drivers reluctant to make long-term changes. Alternatively, behavior can be influenced by redesigning the context within which the behavior occurs. Such an intervention must be effective across demographics and underlying behaviors to achieve ubiquity. The current study investigates the perceived effect on the driving style of a simple graphical dashboard display depicting an animated coffee cup. This display incorporates associative mental models and contextual relevance to increase the salience of inefficient vehicle movements and nudge drivers to adopt smoother driving. An online Amazon Mechanical Turk survey (92 participants) revealed a significant preference for the coffee-cup over a dial-gauge display when controlling for demographic variables. This result offers a preliminary indication that a behavioral nudge may be effective in influencing drivers to adopt eco-driving practices.

ADATABLE INDUSTRIAL 4.0 : AN IMPROVEMENT DETECTED OBSOLETE BUSHING CONDITION ON RUBBER CURING MACHINE INDUSTRY

Bushing is a part of rubber curing machine that have function as cushion pin joint , generally make from a bronze material. Pin joint have a function to connected with 1 paired linkage arm with rotated crank gear of each via pin joint to get closing force at rubber curing machine when mould closed. When bushing condition at pin joint on rubber curing machine was not good caused by friction. It will make closing force linkage arm left and right ( 1 paired ) on rubber curing machine unbalanced. So it will make closing force to force closed rubber mould undistributed evenly, so it caused mould rubber closed with gap. This condition will make defect rubber product open mould after cured finished. In this case is important to find new methode detection and monitored bushing condition. This research was done by measured vibration around pin joint at linkage arm by taking data of sound and acceleration on the real object research and used 2D software simulator to measured bushing condition good or not. Acceleration measurement was done by measured at axis Y and Z by used accelerometer sensor, and accelero sensor on cell phone via sains journal android application. And collected the data stress value on linkage arm by used nidle dial gauge millimeter scale. By simulation software are measured acceleration at axis X and Y with good bushing condition or vise versa.The actual data that was collected : acceleration, sound vibration and stress value and simulated data by software to be compare the amplitude and choose the biggest amplitude as new methode measurement of vibration to detect and monitor bushing condition.From the result data, detection of vibration around pin joint by acceleration value by used accelerometer sensor measured at axis Y and Z more prefer with the other measurement methode.

Adhesion of steel and fiberglass meshes with concrete

Introduction. To prevent the formation of cracks and destruction of masonry structures they are reinforced with meshes at the stage of construction. Compatibility of the reinforcing material and the main body of the structure is an important parameter for the efficient operation of the structure. The article examines the amount of adhesion of fiberglass and steel mesh elements with sand concrete, which is the binding of bricks. Materials and methods. Reinforced beams are tested for bending. Samples of beams consist of two halves connected by a rod in a stretched zone and uncoupled by a hinge in a compressed zone. Elements of steel and fiberglass grids with limited anchorage zones in concrete act as reinforcement. The values of rod slippage in concrete were fixed by a dial gauge. Results. According to the results of the test, the slipping forces of the rods were obtained and the cohesive stresses of the elements of steel and fiberglass grids with concrete were calculated, and diagrams were drawn. The value of adhesion with concrete fiberglass rods was greater compared with the adhesion of steel rods for all values of slip. Conclusions. Fiberglass meshes have a number of drawbacks to steel meshes, however, a large number of positive characteristics of fiberglass meshes, including adhesion with concrete, make them competitive with steel, and in many cases more preferable for use in structures. Keywords: coupling reinforcement with concrete, adhesion, brickwork, reinforcement of structures, masonry mesh, composite materials, steel mesh, composite mesh, innovation in construction/