Biomimetic Rotary Tillage Blade Design for Reduced Torque and Energy Requirement

A rotary cultivator is a primary cultivating machine in many countries. However, it is always challenged by high operating torque and power requirement. To address this issue, biomimetic rotary tillage blades were designed in this study for reduced torque and energy requirement based on the geometric characteristics (GC) of five fore claws of mole rats, including the contour curves of the five claw tips (GC-1) and the structural characteristics of the multiclaw combination (GC-2). Herein, the optimal blade was selected by considering three factors: (1) the ratio ( r ) of claw width to lateral spacing, (2) the inclined angle ( θ ) of the multiclaw combination, and (3) the rotary speed ( n ) through the soil bin tests. The results showed that the order of influence of factors on torque was n , r , and θ ; the optimal combination of factors with the minimal torque was r = 1.25 , θ = 60 ° , and n = 240 rpm . Furthermore, the torque of the optimal blade (BB-1) was studied by comparing with a conventional (CB) and a reported optimal biomimetic blade (BB-2) in the soil bin at the rotary speed from 160 to 320 rpm. Results showed that BB-1 and BB-2 averagely reduced the torque by 13.99% and 3.74% compared with CB, respectively. The field experiment results also showed the excellent soil-cutting performance of BB-1 whose average torques were largely reduced by 17.00%, 16.88%, and 21.80% compared with CB at different rotary speeds, forward velocities, and tillage depths, respectively. It was found that the geometric structure of the five claws of mole rats could not only enhance the penetrating and sliding cutting performance of the cutting edge of BB-1 but also diminish the soil failure wedge for minimizing soil shear resistance of BB-1. Therefore, the GC of five fore claws of mole rats could inspire the development of efficient tillage or digging tools for reducing soil resistance and energy consumption.

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Study on the Interaction between Soil and the Five-Claw Combination of a Mole Using the Discrete Element Method

Applied Bionics and Biomechanics ◽

10.1155/2018/7854052 ◽

2018 ◽

Vol 2018 ◽

pp. 1-11 ◽

Cited By ~ 3

Author(s):

Yuwan Yang ◽

Mo Li ◽

Jin Tong ◽

Yunhai Ma

Keyword(s):

Discrete Element Method ◽

Discrete Element ◽

Rake Angle ◽

Soil Resistance ◽

Distance Ratio ◽

Soil Failure ◽

Soil Cutting ◽

Soil Bin ◽

Rupture Distance ◽

Element Method

A mole is a born digger spending its entire existence digging tunnels. The five claws of a mole’s hand are combinative to cut soil powerfully and efficiently. However, little was known in detail about the interaction between the soil and the five-claw combination. In this study, we simulated the soil cutting process of the five-claw combination using the discrete element method (DEM) as an attempt for the potential design of soil-engaging tools to reduce soil resistance. The five-claw combination moved horizontally in the soil bin. Soil forces (draught and vertical forces) and soil failure (soil rupture distance ratio) were measured at different rake angles and speeds. Results showed that the draught and vertical forces varied nonlinearly as the rake angle increased from 10 to 90°, and both changed linearly with the speed increasing from 1 to 5 m/s. The curve of the soil rupture distance ratio with rake angles could be better described using a quadric function, but the speed had little effect on the soil rupture distance ratio. Notably, the soil rupture distance ratio of the five-claw combination in simulation was on average 19.6% lower than the predicted ratio of simple blades at different rake angles indicating that the five-claw combination could make less soil failure and thereby produce lower soil resistance. Given the draught and vertical forces, the performance of the five-claw combination was optimized at the rake angle of 30°.

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Comparison of soil and corn residue cutting performance of different discs used for vertical tillage

Scientific Reports ◽

10.1038/s41598-021-82270-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Zhiwei Zeng ◽

Dillon Thoms ◽

Ying Chen ◽

Xu Ma

Keyword(s):

Cutting Forces ◽

Crop Residue ◽

Conservation Agriculture ◽

Cutting Performance ◽

Promising Practice ◽

Corn Residue ◽

Different Shapes ◽

Soil Cutting ◽

Soil Bin ◽

Corn Residues

AbstractHigh amount of corn (Zea mays L.) residue left in the field interferes with seeding operations, which hinders the viability of conservation agriculture. Vertical tillage is a promising practice in dealing with heavy crop residue, but its effectiveness largely depends on the design and use of tillage machines. In this study, three vertical tillage discs with different shapes, namely notched, plain, and rippled, were tested in a soil bin at two different working depths, shallow (63.5 mm) and deep (127 mm). Corn residues were spread on top of the soil as surface residue. soil cutting forces, soil displacement, and residue mixing with soil, as well as residue cutting were measured. The results showed that the working depth had a stronger effect on the performance of discs as compared to the disc type. No difference in residue cutting was found between the treatments. The deep working depth resulted in 5.1% higher residue mixing, 53.4% greater soil cutting forces, and 34.9% larger soil displacements, as compared to the shallow depth. The rippled disc resulted in the largest soil displacements with the greatest demand in soil cutting forces. Overall, the rippled disc was the most aggressive among the three discs with regard to the performance indicators measured. The results suggested that varying working depth would be an effective approach in changing the soil dynamics and residue cutting performance of the discs for vertical tillage.

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Design and Experiments of a Bionic Hook-Shape Subsoiler

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.461.50 ◽

2013 ◽

Vol 461 ◽

pp. 50-56

Author(s):

Qiang Zhang ◽

Lu Lu Yu ◽

Hong Lei Jia ◽

Xian Jun Liu ◽

Li Zhang

Keyword(s):

Experimental Tests ◽

National Standard ◽

Operating Speed ◽

Power Requirement ◽

Design Concepts ◽

Speed Range ◽

Arc Shape ◽

Structure Scheme ◽

Resistance Decrease ◽

Soil Bin

Based on study of morphology of animal claws and subsoiling characteristics of subsoiler, a bionic hook-shape subsoiler is designed to decrease its operating resistance and to improve the terrain surface morphology. Design concepts and the structure scheme of the subsoiler are presented. The influences of tillage depth and operating speed on the operating resistance of bionic hook-shape subsoiler are examined in soil bin experimental tests by compared with a standard arc-shape subsoiler regulated by national standard (JB/T 9788-1999). It is proved by experiment results that the bionic hook-shape subsoiler when the operating speed range is 4-5km / h, compared with the standard arc-shape subsoiler, showed much lower operating resistance and power requirement against soil. The resistance-decrease index of the bionic hook-shape subsoiler is 24.1%, 24.4% and 26.5% at 300, 350 and 400mm cutting depth, respectively.

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Calculation of the power requirement for soil cutting by rotary tool blade

Journal of Physics Conference Series ◽

10.1088/1742-6596/1679/2/022050 ◽

2020 ◽

Vol 1679 ◽

pp. 022050

Author(s):

Yu V Konstantinov ◽

A P Akimov ◽

V I Medvedev ◽

A N Maksimov

Keyword(s):

Power Requirement ◽

Rotary Tool ◽

Soil Cutting

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The SPARKy (Spring Ankle With Regenerative Kinetics) Project: Design and Analysis of a Robotic Transtibial Prosthesis With Regenerative Kinetics

Volume 5: 6th International Conference on Multibody Systems, Nonlinear Dynamics, and Control, Parts A, B, and C ◽

10.1115/detc2007-34512 ◽

2007 ◽

Cited By ~ 30

Author(s):

Joseph K. Hitt ◽

Ryan Bellman ◽

Matthew Holgate ◽

Thomas G. Sugar ◽

Kevin W. Hollander

Keyword(s):

Peak Power ◽

Sagittal Plane ◽

Mechanical Design ◽

Energy Requirement ◽

Human Gait ◽

Total System ◽

Power Requirement ◽

Prosthetic Devices ◽

Ankle Motion ◽

Continuous Power

Even today’s most sophisticated microprocessor controlled ankle-foot prosthetic devices are passive. They lack internal elements that actively generate power, which is required during the “push-off” phase of normal able-bodied walking gait. Consequently, lower limb amputees expend 20–30% more metabolic power to walk at the same speed as able-bodied individuals. Key challenges in the development of an active ankle-foot prosthetic device are the lack of high power and energy densities in current actuator technology. Human gait requires 250W of peak power and 36 Joules of energy per step (80kg subject at 0.8Hz walking rate). Even a highly efficient motor such as the RE75 by Maxon Precision Motors, Inc. rated for 250W continuous power with an appropriate gearbox would weigh 6.6 Kg. This paper presents the first phase of the Spring Ankle with Regenerative Kinetics (SPARKy 1), a multi-phased project funded by the US Army Military Amputee Research Program, which seeks to develop a new generation of powered prosthetic devices based on the Robotic Tendon actuator, that significantly minimizes the peak power requirement of an electric motor and total system energy requirement while providing the amputee enhanced ankle motion and “push-off” power. This paper will present data to show the kinetic advantages of the Robotic Tendon and the electro-mechanical design and analysis of SPARKy 1 that will provide its users with 100% of required “push-off” power and ankle sagittal plane range of motion comparable to able-bodied gait.

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FINITE ELEMENT MODELLING OF TILLAGE TOOL DESIGN

Transactions of the Canadian Society for Mechanical Engineering ◽

10.1139/tcsme-1993-0016 ◽

1993 ◽

Vol 17 (2) ◽

pp. 257-269 ◽

Cited By ~ 1

Author(s):

R.L. Kushwaha

Keyword(s):

Finite Element ◽

Finite Element Model ◽

Three Dimensional ◽

Element Model ◽

Rake Angle ◽

Interface Elements ◽

Tool Shape ◽

Soil Cutting ◽

Soil Bin ◽

The Finite Element Model

A non-linear finite element model was developed for three dimensional soil cutting by tillage tools. A hyperbolic constitutive relation for soil was used in the model. Analysis was carried out to simulate soil cutting with rectangular flat and triangular tillage blades at different rake angles and with curved blades. Interface elements were used to model the adhesion and the friction between soil and blade surface. Soil forces obtained from the finite element model for the straight blades were verified with the results from laboratory tillage tests in the soil bin. The finite element model predicted draft force accurately for both tillage tools. Results indicated that the draft was a function of rake angle, tool shape and the curvature.

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