ENEM14016 Fluid Machinery: Excavator Design Optimization & Simulation

This project focuses on the design optimization and simulation of a hydraulic excavator using MATLAB and SimScape. It includes a literature review, basic concepts of hydraulic excavators, excavator selection, and detailed design calculations. The project determines the Denavit-Hartenberg parameters, analyzes and compares results, conducts a parametric study, and explores geotechnical applications. The excavator arm is modeled as a 3-DOF controller, and the Jacobian determined from the MATLAB model is used for parametric investigations. The geo-mechanical properties of soils are considered to provide a semi-ideal solution for effective excavating. The aim is to model the excavator motion and behavior to estimate the optimum orientation and lengths of the excavator arms that maximizes the efficiency of force applied during excavation.

Design Optimization and Simulation of Hydraulic Excavator using Matlab and SimScape

Table of Contents
Introduction......................................................................................................................................3
Literature Review............................................................................................................................5
Basic Concepts of Hydraulic Excavators........................................................................................9
Excavator Selection.......................................................................................................................13
Design & Calculations...................................................................................................................15
Position of joint 1.......................................................................................................................16
Finding of θ1...............................................................................................................................16
Position of joint 2.......................................................................................................................16
Finding of θ2...............................................................................................................................17
Position of joint 3.......................................................................................................................17
Position of B...............................................................................................................................18
Position of C...............................................................................................................................18
Position of D..............................................................................................................................19
Position of F...............................................................................................................................20
Position of H..............................................................................................................................20
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Position of Joint 4......................................................................................................................21
Position of G..............................................................................................................................21
Position of M..............................................................................................................................21
Denavit Hartenberg parameters.................................................................................................22
Analysis & Comparison of Results................................................................................................23
Parametric Study........................................................................................................................23
Geotechnical Applications.........................................................................................................26
Conclusions....................................................................................................................................29
References......................................................................................................................................30
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Executive Summary
Uses of hydraulic excavators: construction for multiple purposes and also for making
instruments. A boom, a bucket, and two hydraulic cylinders are the parts of the hydraulic
excavator's arm. Boom is the upper part of the arm. These arms will move like a human arm
which consists of a wrist and elbow. Oil is used to move the arm. A piston and rod in the
hydraulic cylinder empower the arm to move. In the end portion of the piston, oil is pumped and
hits the rod through the cylinder. This causes movement of the arm. We can simply manipulate
the accuracy of the arm by preventing the amount of oil which is pumped through the valve. The
digging motion of an excavator can be divided into 3 mechanisms; penetration, separation, and
secondary separation, which constantly put different contributions to the generation of soil
resistance in the digging process. The digging motion and force applied by the end bucket is
determined by the mixture of these 3 main mechanisms at different stages of digging process.
The hydraulic cylinders in the excavator arms are limited to linear actuation. Hence, their mode
of operation is fundamentally different from cable-operated excavators which use winches and
steel ropes. The boom (upper arm) and bucket attached to the body work in conjunction to move
materials, but are controlled independently. Hence, the optimal position for maximum efficiency
regarding digging needs to be assessed. The movement of the excavators arms can be modelled
as a manipulator and the movement/position of the end bucket can be computed using the body
and space Jacobians associated with the excavator. Using these techniques, our aim is to model
the excavator motion and behavior with MATLAB and to estimate the optimum orientation and
lengths of the excavator arms that maximizes the efficiency (power usage) of force applied
during excavation.
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Introduction
In this venture, we demonstrated a nonexclusive excavator arm as a 3 DOF controller and
determined its DH and screw parameters. The Jacobian determined from the made model of the
excavator in MATLAB was utilized to lead parametric investigations with respect to the joint
edges and connection length proportions. The geo mechanical properties of the uncovered soils
were considered to give a semi-ideal answer for the information joint plots for compelling
exhuming.
To exhibit and move extensive product, an excavator is used. It is a development vehicle.
It has major two sections: an improbable blast arm which is related to a driving base. It has a
connection planned for uncovering. A small taxi is related with the base. In this small taxi, the
administrator will sit and guides the arm. To create a Hydraulic power, the excavator uses a
hydraulic framework which is used to control the mechanical arm. It also uses a chain wheel for
its improvement.
There are 3 techniques on the best way to work an excavator 1.Power and Drive. An
excavator keeps running on diesel control since it creates a higher torque and is increasingly
hearty for substantial work. The motor powers the tracks which are like tank tracks, and the
water powered engines which raises and broadens the excavator arm. All power is provided by
the diesel motor, and the controls for development in forward and invert are worked from the
control lodge. An administrator will utilize pedals and switches to push the machine ahead and in
reverse, and to control the vehicle. 2. Excavator Arm. The excavator arm is attached to the
bottom of the edge case. There are three water powered cylinders. These cylinders are covered
with steel cylinder arms. This arm must consists of a loader and two parts. The two parts are
attached with a pivot. One cylinder is attached to the bottom side of the first part. The other
cylinder is situated upwards to the next part. When the first cylinder broadens the poll pushes in
opposition to the arm, moves upwards and the area had expanded. The other arm shrinks and
expands, take upwards and downwards the part. There is a cylinder which gives more pressure. It
pushes the container loader ahead and conversely.3.Track steering (Using fem we can analyze
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and optimize the bucket teeth of hydraulic excavator, 2017). The tracks are not flexible. They are
located near a progression of apparatuses. It transfers the energy from a drive shafting
accordance with the motor. When in rigging the track moves the machine towards front or back
in a straight line. For turning machine, one track is fully ceased and the next track is used for
moving towards the front or back. This takes the machine turn in a curve. To make the device in
a total circle shape an administrator is used to put one track to move forward and the next track
to move backward.This requires two separate drive frameworks, and a progressively confused
transmission. It isn't accessible on all vehicles. What's more, a few excavators have a rotating
taxi that can swivel 360 degrees. This is fueled by another pressure driven engine that gets drive
from the principle motor.
Excavators are utilized for numerous reasons and is presumably the most regularly
utilized machine in the development business. A few applications are recorded underneath:
Digging of channels, gaps, establishments, material taking care of, general evaluating/finishing,
brush cutting with water powered connections, ranger service work, obliteration, lifting and
setting of funnels, mining yet not constrained to open-pit mining and waterway digging.
Exhibitions of excavators are constrained by the point and directivity of the controllers.
Power that given by excavators isn't show 100%. There are numerous elements that influence the
kinematic manipulability of the excavator arms. This report plans to give understanding into the
development of excavators and their association with the ground. There are two sorts of heading
that one can be work enormous power and other can be work little power, on the grounds that the
opportunity of bucket (end of excavator) is controlled by the turn hub and area of each
connection. This can be express utilizing the information from a Jacobian circle and
communicated as function (=length of oval hub as indicated by/the real pivot of the oval) as per
(about among basin and ground). The subsequent esteem, named the 'viable vulnerability',
communicates proportion about excavator’s development. (Yuan, 2014)
To show the excavator movement and conduct utilizing kinematics. This report will
demonstrate Jacobian-circle by utilizing DH parameter in light of the fact that we need to
contrast the directional pattern about power with locate the ideal direction and lengths of the
excavator arms that amplifies the productivity (control utilization) of vertical power connected
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amid exhuming. Discover the proportion among 3 length of every connection by some
procedure, and discover area of link1, link2 and link3 so as to guarantee most extreme execution
when the excavator burrows ground. That area can be improved proficiency about power (Chen
& Chen, 2011).
Literature Review
Infrastructure development relies a lot on hydraulic excavators and are considered to be
‘Earth Movers’. They play a vital role in excavation, construction of roads and building, mining
of granite, coal, or and many more. Equipped with work implement or attachment which include
buckets for digging and carrying materials, hydraulic hammers and drills, excavators help
perform important, heavy-weight tasks . For Multi Body Simulation analysis, computational
simulation method is used which aims to reduce the number of repetitions during the
development phase. A precise restricted code such as Altair Radios is used in the simulation
process. Furthermore, to improve the Lower Arm Excavator model, it is optimized for it to get
less weight and tense component. In this paper, FE analysis of Excavator of Lower Arm is
explained. To reduce the time required and the expenses for the development process, the results
obtained from CAE analysis are evaluated, keeping in mind the requirements. The project aims
to design and conduct Multi Body Simulation analysis for excavator and execute Topology
Optimization so the weight of the lower arm of the excavator can be reduced. To view the results
in hyper view, Catia V5 R19 for the modeling of the excavator and preprocessing in hyper mesh
and radios can be utilized. For reduction in weight,, Altair Optistruct is recommended and a
revision in lower arm of the excavator’s design is urged. The paper hopes to shed light on the
topology optimization approach which can be used to create a unique design of the lower arm of
the excavator. Along with this, the paper aims propose techniques that are effective to design and
develop high quality products at minimum expense. After looking at both the designs, the author
came to eh conclusion that the second design is more relevant to the aims of the paper
("DESIGN AND ANALYSIS OF EXCAVATOR BUCKET TOOTH", 2018).
An example of heavy equipment is an excavator which consists of jointed arm, which
known as a backhoe, a bucket and a rotating platform on which the cabins mounted, an
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undercarriage with wheels and tracks. By using CAD-CAE systems, it is aimed to go beyond the
available material to improve the design of excavators and pinpoint the problems faced by them
when performing tasks like digging and lifting. Generally, mini hydraulic backhoe excavators are
used for light construction jobs and are mostly used when soil needs to be excavated. In
operations like digging, the design of backhoe excavator is very important which is developed
through actuators. For the developed design to be safe, the resistive forces of the surface that
needs to be excavated needs to be lesser than the forces produced by actuators. Consumption of
fuel and the productivity of the excavator are two vital factors that need to be considered when
the arm of the excavator is designed. During operations like digging and lifting, current
mechanism which is used in the arm of the excavator is exposed to torsional and stress caused by
bending. To get past this problem, the need of a new mechanism of excavator was realized and a
3D model of the excavator arm linkage was designed using the Pro-e software. A static analysis
of all the arms of the excavator’s components was done, keeping in mind the existing force
produced by the components as well as the new force calculated for digging with the help of
ANSYS workbench software. To deal with the loss in production which is caused by the
reduction in the digging force, an increase in the bucket volume is recommended. ("DESIGN
AND OPTIMIZATION OF EXCAVATOR", 2017) This paper aims to achieve positive analysis
results which prove that the new design of the excavator is safe for the digging force that has
been calculated.
Design and analysis of hydraulic excavator are one of the complicated processes. It involves the
CFD analysis such as FEA analysis. When talking about accuracy that makes the process more
complicated. Especially in practical problems, the explicit mathematical formula won't bring 100
% correct answers all times. Because some of the design variables are very difficult to formulate.
In some cases, it is impossible to develop a mathematical model. So that in modern process
scientists and researcher use surrogate model. In this paper also author used different surrogate
models to optimize the performance of the system. Here the author selected a number of
surrogate models suitable for excavator performance analysis. And the different methods
compared in this paper are surface methodology, support vector machine, and radial basis
function etc. After comparing all the methods the author selected the most suitable method for
the optimization process. And the author also developed the new concept. Here author used the
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bionic intelligent optimization algorithm. In this paper, the author stated that the bionic algorithm
brings the optimum results (Xu and Yoon, 2019). Also, the magnitude of the stress calculated by
using the FEA technique is similar to the value founded by this algorithm. In the case of
efficiency, the present model has higher efficiency than the developed or proposed model in this
article. The new concept proposed in this paper mainly based on the length of the joints, the
angle between the hinges etc. Here the author successfully applied this concept on the design
process. And also the author simulated the concept using Matlab. Using the simulation author
measured the effectiveness of the sample points. In all the measured sample points the author
founded the improvement of effectiveness. Also expressing the different variables in terms of
length is not practically feasible. Because this method creates some errors & conflicts. This
method uses trigonometric functions. Usage of trigonometric functions instead of computational
variables and formula brings higher flexibility and advantages. Also, the proposed method is far
simpler than the conventional method. Also, the author considered different variables and their
influence on the final accuracy. In the optimization process, the author used the BIOA technique.
Here the author iterated the maximum stress values in terms of boom, arm and bucket. Here we
can't find any convergent violations, but the convergence velocity for the different points are
different. And the magnitude of the maximum stress in the bucket is 290.63 MPa, and maximum
stress in the boom is 248.09 MPa, and the maximum stress in the bucket is 221.91 MPa. These
are the founded values from this method. As per the results of this study the magnitude of the
maximum stress founded by both FEA technique and this technique has the same value (Qiu, Li
and Feng, 2016). Although the author verified the RSM model and its functionality and proved
this method is one of the most viable methods for conducting the design process for improving
the performance of the hydraulic excavator.
Tackles, pulleys, levers, and block were used for lifting the weight in early times.
Mechanical linkages gained movements for a ship’s rudder and steering a vehicle. These
mechanical linkages were gears, couplings, levers, and cams. This made the system more
complex. There were several drawbacks occurred in manual and mechanical methods. Big man
power should involve in them for a different job (Usman, Lawal and Shehu, 2014). Overtime
working was also involved. When the technology and population developed, the need for faster
and simpler apparatus also developed. Because of these needs, hydraulic machines were
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established. A hydraulic is a simple system which includes hydraulic fluid, cylinders, pistons or
rams, accumulator or oil reservoir, safety device and a complete working mechanism. In a
medium, these hydraulic system are able to control a wide variety of apparatus which can
transfer force. This is carried by hydraulic fluid. Engineering and transportation fields uses
modern hydraulics. These system transmit high force quickly and correctly. They can transfer
even in small pipes of less weight, any shape, and over a small distance (FAN, 2017). These
system can play an important role in the field of small steering of car to manipulated devices of
the supersonic aircraft. In big ships, more strong and efficient system are used. The most famous
scientist Blaise Pascal proposed the law which is known as Pascal’s law. It implies that pressure
at a point has infinite direction and thus a pressure change at any point in a confined
incompressible fluid is transmitted throughout the fluid such that same change occurs
everywhere. (Khan, Islam & Hossain, 2016) This is the major principle of hydraulic system.
Blaise Pascal is a French mathematician. The force acting per unit area is known as Pressure.
The force applied perpendicular to the surface of an object per unit area over which that force is
distributed. Hydraulic pressure is the pressure of the hydraulic fluid which it exerts in all
direction of a vessel, hose or anything in which it is supposed to exert the force per unit area.
This pressure is responsible to create flow in a hydraulic system as fluid flows from high
pressure to low pressure.
Example of simple hydraulic system is a closed toothpaste. Consider the toothpaste as a
hydraulic fluid which is inside the system. Put four or five holes on the tube. By keeping the cap,
apply force at a particular point on the tube. Then we can see that the paste will come out from
the hole that we made. This is one of the example of Pascal’s law. The force on the particular
point of the tube is equal to the force on all other parts of the tube. That is, the force is
perpendicular to the walls of the restricted area (Usman, Lawal and Shehu, 2014). Brakes used in
automobile is another example of the hydraulic. When the driver applies brake to the vehicles,
the brake pedal acquires force and transmitted it to the hydraulic fluid under the piston. This is
same as the force applied to the brake shoes. This causes the vehicles to stop. Hydraulics are
applied in hydraulic cranes, petrol pumps, automobile garage, automobile brake, and robotics
and so on.
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Excavator is a heavy construction equipment. This project describes about how to design
and analysis all component of an excavator. 'Bucket teeth' is the important part of the excavator.
It has various substances with impact load. These substances are differentiated to strain energies,
von mises stresses and deformations. The optimum component is weightless, strong and
sustainable. Therefore, the bucket has minimum weight and maximum strength. The cost of
manufacture and material saving are available. CATIA is used for its assembly and ANSYS for
analysis. Excavator bucket is manufactured with steel. Cast iron, steel and wrought iron are
materials used for analysis. Comparisons are seen in the strain energy, deformations and von
mises stresses. The weight of the steel is 7840 kg. The weight of the cast iron is 7300 kg and that
of wrought iron is 7550 kg. Deformation of the steel is less. But the deformation of wrought iron
and cast iron is greater than that of the steel. In the case of wrought iron, it can resist the load
with least deformation. Von mises stresses of cast iron is greater than that of wrought iron and
steel. The strain energy of wrought iron is more than that of steel and cast iron. The weight of
wrought iron is less but its strain energy is high (Solazzi, 2010). Stresses are low in it and
displays formal deformation. When we replace steel with wrought iron, wrought iron become
hard, tensile and flexible. It reduces its weight because of the same strength. Therefore, we can
save time and cost. Wrought iron is very strong. So we cannot break or destroy it. To avoid rust
in wrought iron, we must keep an efficient paint job. It has no need of maintenance and it can
resist with the weather. Due to these advantages, we can replace steel with wrought iron.
Wrought iron is an alloy of iron. It has low carbon content compared to cast iron. Mild steel is
produced from wrought iron. It includes nuts, chain, bolts, rails and wire. Cast iron is a ferrous
alloy. When it is heated, it will be liquefied. It is made from pig iron. Steel is also an alloy of
iron and includes carbon. We know that CATIA is used to design every component of an
excavator. Assembly is also done in CATIA. It is used by aerospace industries (Qi & Zhang,
2014). Most of the industries are architecture, construction, electronics, medical, automotive,
machinery, mold and die and so on. It is found in all over the world. In ANSYS, analysis and
meshing are accomplished through it. Universally, steel is used in excavator bucket. It provides
the means to balance the requirements and occur right mesh. In engineering simulation, mesh
generation is one of the major aspects. Excavator is used for digging holes, handling the
materials, forest work, mining, dredging the river, landscaping, and clearance .Bucket is used for
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digging and to move the materials. To operate excavator, excavator boom is maintained. The
excavator boom and bucket can be handled by the operator’s cabin machine.
There is a method for doubling force by a fluid that is not compressible is named as
hydraulics. Basically: oil. Hydraulic machines use liquid fluid power. The basic example is a
heavy equipment.so liquid is the main medium in it. Control valves are used to control fluids
directly and it also distributes by using tubes and hoses. Hydraulic power was mainly used in
Bessemer steel productions. Hydraulic fluid is passed to the machine to different motors and
cylinders. Air is more compressible than hydraulic oil (Shetiye and Kungwani, 2018). The force
at the first stage is kept at one end and a stable pressure at another end. At one end of the system
a force of 10 pounds is applied. It consists of 1 square foot cross section. The final output is an
applied pressure of 10 pounds of cross section. It finalizes a force of 100 pounds. The piping
connections between two pistons are of any type. There is one base cylinder which gives force to
the sub cylinder. This is a very good mechanism. Scientific principles are used by hydraulic
equipment. There is a pump used for operating engines and motors. These pumps generates
pressure to the hydraulic fluid. The fluid passes through tubes to actuators. The arm or bucket in
excavation is done by the actuators. Hydraulic system mainly consists of valves, pumps, filters
check valves, hydraulic cylinders etc. Hydraulic multiplication is defined as the tradeoff within
the base and sub cylinder. It is within the movement and current force. Mechanical hydraulic
systems used by vehicles are joined by a group of valves and piping it. (Khan, Islam and
Hossain, 2016) This gives oil with heavy pressure. It is essential that these joining recollects the
tight seals.
Seal integrity is not essential. It is essential that the entry of air bubbles are not allowed.
The force produced by the system takes care of compression of air. It normally decreases the
force and goodness of system when they are not safe. The mobile based machines with six
hydraulic actuators. It is named as crawler excavators. The six hydraulic actuators are boom,
bucket, lift arm, travel left, and travel right and swing. These union gives certain orders to the
hydraulic system. The movements in crawler excavator’s hydraulic system must be sensitive,
smooth and it is not dependent. The engine output must be hydraulically must be translated
100% clearly by an excavator's drive system. In comparison with engine output the hydrostatic
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