Development of a novel mechatronic system for mechanical weed ...

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Materials and methods P = η * P (4.5) 52 out in After imputing Equation (4.5) and transforming the Equation (4.4) the output torque becomes the following form M = η * G * M (4.6) out in By gearboxes attached to each other the final coefficient is a multiplier of the individual efficiency coefficients. The backlash is an important characteristic of a gearbox and can be defined as the possible angular displacement of the gearbox’s output shaft while the input shaft remains stationary. Simple gears can have a few degrees of backslash, precision gears much less and special gear systems like harmonic drive gears nearly zero. The main characteristics of a gearbox, such as maximum allowed torque at the output shaft and maximum allowed speed at the input shaft, are given in their specification. 4.3.1.3 Adjustment of the parameters of the servo drive The chosen servo drive allows 4 types of control: � speed control (controls servomotor speed by means of an analog voltage speed reference), � position control (controls the position of the servomotor by means of a pulse train position reference), � torque control (controls the servomotor’s output torque by means of an analog voltage torque reference) and � contact input speed control (three operating speeds can be set in the drive and activated by switching).
Materials and methods The drive contains a mathematical model of the whole system based on the mechanical inertia ratio of the system. The inertia ratio parameter is given as a percentage of the ratio between the inertia of the load and motor inertia. This parameter need to be properly set to optimise the speed gain. In the traditional approach, inertia ratio needs to be calculated, using the dimensions and densities of each component in the load, before the selection of the servomotor as a decisive parameter for its sizing. The total inertia of the system is a sum of the coupling, the screw and the load inertias. However, specifications of all elements are often unreliable or unavailable and the complexity of the system can be a limiting factor for accurate calculation of the load inertia. The servo drive has an online auto-tuning algorithm but external factors can often limit its accuracy. A simple technique based on graphical analysis of the speed and torque values in the starting sequence, before the system reaches the steady state, can be applied. In this method the same equations are used as for motor sizing, but in reverse. The graphically determined torque and speed characteristics can be used to calculate the inertia of the load. The equation for accelerating torque calculation (Equation 4.7) can be transformed to solve it for JL (Equation 4.8) M = ( J + J ) * α (4.7) A M L MA JL = − JM (4.8) α where MA is the torque it takes to accelerate, JM is the inertia of the motor, JL is the inertia of the load and α is the actual acceleration of the motor. Typical change of the torque intensity which can cause a trapezoidal response of the speed (acceleration, constant speed and deceleration) is illustrated on the diagram in Figure 4.6. 53
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Institut für Landtechnik der Rhein
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Development of a novel mechatronic
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Kurzfassung Entwicklung eines neuar
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Acknowledgements Acknowledgements M
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Table of contents Table of contents
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Glossary of abbreviations and symbo
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Symbol Unit Description Mmmax Nm Ma
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Symbol Unit Description Glossary of
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ωold ωout rad s -2 Latest rotatio
Page 20 and 21: Introduction The most frequently us
Page 22 and 23: Introduction application that had p
Page 24 and 25: Introduction be to go from a system
Page 26 and 27: Introduction limited and environmen
Page 28 and 29: Introduction than 40 years before g
Page 30 and 31: Introduction techniques. It is know
Page 32 and 33: Introduction Sowing and planting al
Page 34 and 35: Introduction Inter-row weeding syst
Page 36 and 37: Introduction 18 Figure 1.3 Inter-ro
Page 38 and 39: State of the art 20 Figure 2.1 a) F
Page 40 and 41: State of the art cylinder rotates a
Page 42 and 43: State of the art 1998). This device
Page 44 and 45: State of the art 26 2.2 Detection o
Page 46 and 47: State of the art The fluorescence s
Page 48 and 49: Definition of the problem and resea
Page 51 and 52: 4 Materials and methods 4.1 Detecti
Page 53 and 54: Materials and methods Figure 4.1 a)
Page 55 and 56: Materials and methods Figure 4.3 a)
Page 57 and 58: 4.1.2 Data acquisition 4.1.2.1 Hard
Page 59 and 60: 4.1.4 Test objects Materials and me
Page 61 and 62: Materials and methods become a poss
Page 63 and 64: Materials and methods environments
Page 65 and 66: Materials and methods dimensions ne
Page 67 and 68: Materials and methods (PFM). As the
Page 69: Materials and methods A command sig
Page 73: Materials and methods Another tool
Page 76 and 77: Results and discussion 58 Figure 5.
Page 82 and 83: Results and discussion objects. Acc
Page 84 and 85: Results and discussion Plant positi
Page 86 and 87: Results and discussion Plant positi
Page 88 and 89: Results and discussion 70 5.1.4 Dis
Page 92 and 93: Results and discussion Connection b
Page 94 and 95: Results and discussion 76 5.2.1 Opt
Page 96 and 97: Results and discussion xmi1 = ( RLA
Page 98 and 99: Results and discussion With the inv
Page 100 and 101: Results and discussion 82 Horizonta
Page 102 and 103: Results and discussion 84 5.2.4 Sel
Page 104 and 105: Results and discussion 86 5.2.5 Dis
Page 106 and 107: Results and discussion Conventional
Page 108 and 109: Results and discussion Since the fi
Page 110 and 111: Results and discussion To avoid con
Page 112 and 113: Results and discussion As the size
Page 114 and 115: Results and discussion 96 5.3.4 Alg
Page 116 and 117: Results and discussion 98 V = zc( t
Page 118 and 119: Results and discussion corresponds
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Results and discussion 102 5.3.6 Me
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Results and discussion hoeing accur
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Results and discussion between the
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Results and discussion distance fro
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Results and discussion Distribution
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Results and discussion cuts are ran
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Results and discussion Forward spee
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Results and discussion x [mm] Distr
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Results and discussion The experime
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6 Summary Summary Neither a mechani
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Summary The third part of the work
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7 Conclusions Conclusions The prese
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8 References References Agrios, G.
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References in California's Sacramen
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References Johnson, W C and Mullini
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References Schans, D. v. d. et al.
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List of figures List of figures Fig
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List of figures Figure 5.24 Scheme
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Plant position 9 Appendix Table 9.1
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Plant position Table 9.3 Detection
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Personal data Education About the a
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