Final Report

ME 3011 Kinematics & Dynamics of Machines Capstone Term Project

An Interim Report on Kinematic & Dynamic Analysis of “Car Windshield Wiper” Submitted By: 1-Khalifa Alblooshi 2-Abdullatif Alsakran Submitted to: Dr. Bob Submission Date: 06/07/2017

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TECHNICAL MEMO The objective of this project is to conduct a dynamic and kinematic analysis of the practical limit mechanisms involving any machinery. Therefore, we chose the "car’s windshield wiper." In this way, the one who would drive out a nail of the residual iron in the chair as the center of unity can cover the windshield the windscreen. Typically a simple configuration, and the edge of the mat is used to centrally windshield and the front and rear of the cars. These mechanisms are specific systems for vehicles in which it emotionally accounts from the pivot axis by a wiper motor assemblies couplings. It consists of the components wiper system usually have agreements with: (1) the crank joint (2) crank the motor (3) Gear wiper (4) base plate steel, (5) wiper with a motor thermo-switch (6) pivot shaft assembly with plate (for parallel wipe pattern), and (7) second set of a bar pivot shaft with the vehicle. A common supported by the strength of the sheet metal lorem.

CONTENTS 2

1.

INTRODUCTION.............................................................................................................................3

2.

MECHANISM DESCRIPTION AND MODELING.......................................................................4

3.

ANALYSIS.........................................................................................................................................5

4.

3.1.

Kinematics..................................................................................................................................5

3.2.

Dynamics....................................................................................................................................5

RESULTS...........................................................................................................................................6 4.1.

Kinematics..................................................................................................................................6

4.2.

Dynamics....................................................................................................................................6

5.

DISCUSSION.....................................................................................................................................7

6.

CONCLUSIONS................................................................................................................................8

APPENDICES...........................................................................................................................................9

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1. INTRODUCTION A device which is used to remove the rain, snow, ice, and from the windscreen or any obstructions from the windshield is windscreen wiper. Today, almost all of them are equipped with the wipers of motor vehicles are such things to be holy. Hence, it is a statute forever. Wiper arm, usually from metal edges on one end of the long sword trash together. A case in point is the power arm hang, usually an electric motor, and some vehicles that use pneumatic control. Where the grass and turned on the windshield or water precipitates each of us. Normally it is not the speed or the weekend. 2 utility vehicles, many of the arms race radiation to be synchronized with a number of other vehicles for commercial or pantograph arms. A windshield washer 'system is also used in some vehicles. This system is a noose "Antifreeze window washer fluid," the nozzles on the windshield. This helps to remove dirt and dust with the system, together with the swords in the surface is to use the wiper. By using antifreeze windshield washer fluid is easy to remove ice and snow wipers. Even in winter, hot vehicles either in terms of some windows and glass embedded heating wire. The ice and snow from building up on the surface of the heating systems such as windscreen. In some rare cases, a miniature wipers, headlights have been installed.

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How Does A Windshield Wiper Works? Profit there in the windshield wiper mechanism is motor itself, which was to take up in the power of the wiper to the needs of. Wipers, windshield wiper motor output rotational turned back a series of motion. Rubber plate rubber leaf spring arms and the series appears to be. The two are usually standard wipers 1's drive in the middle of the detergent to the mirror and the other in front of the front seats. Wiper wipers, vehicle or something more than just the former. 2 wipers move more than usual arrangement includes a mirror at last to be cleaned. Pivots safety; and that it is connected on both sides, for the tribes go up is often slow wipers, link hooks. In fact, the pressure is not enough to use the arms which it made from iron, wipers, Wiper one pair of points of the rubber to be established. In order to keep fixed pressure points on the windshield glass is intact rubber blade for cleaning the windshield. The maximum number of points in the wiper pressure, the more the pressure generated on the windshield. It also includes rubber blade iron frame by frame to some intermittent openings and holes, which then makes it easy for replacing rubber blade. Of the rubber according to the season, so that a part of Wiper: one falls before it wears out.

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MECHANISM DESCRIPTION AND MODELING Some major requirements for a “Car windshield wiper” mechanism can be identified as described below: 

1 DOF (Straight Line)



Fixed link frame

Mechanism Simplification For wiper mechanism, the mobility of step (DOM), obtained in GRUBLER comes; i.e. D.O.M = 6n - Σrg = 30-29 = 1; And here we will not equal to n. the entire movable body Σrg = p. of Constraints (geometric) Roman RG 5 = - Joint revolute, Roman RG = 4 - cylindrical gas, AC 3 = - spherical Ed.) Now, in kinematic model, the manufacture is powered by a motion generating class ω1 (t). But crank the motor, an approach speed of 65 = -1 [rot / min] we obtained: ω n1 = 1/30 is ω = 6,803 6,803 = 1t 1 = ω t [couch / sec].

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Modelling Just after knowing the modeling Infusion of work Using SAE J903c can be determined through the windshield own country sweeps may not satisfy apply, "MATLAB Simulink" system for the transmission system into service in the simulation analysis Execute machines. In particular, setting the coordinates at first the second feature soccer decide to count all government policy and sensors mention finally stopped, soccer's own motion may be required output, the output Infusion strategic places, for which reason the middle of the windshield wipers mechanical conceptual plan to explore the Dynamic soccer match. Looking for driving the drum from the wiper of a rigid plate of the rack, and makes use of the Synchronized or in the way of this. Rack actuated by a scotch yoke coupling, i.e. pin-slot model used in the rotary joint motor that turns to one of the rack reciprocal. This compact rack drum rack reciprocating motion is converted into a reciprocating angular lines Wiper blades (i.e. bound to the pinion). The arches convexities, lying on a board in the opposite direction, connecting the kind of thing that has a very low noticeable variation on the "straight line"

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ANALYSIS 1.1.

Kinematics Analysis

An analyses flow chart shown in the windshield wiper mechanism in the form below. The objective is the same reason carefully considered efficient Configuration i.e. Suitable mechanical "system Wiper". Such syntheses can be made by considering a de descriptions of composition, which is based on the theory of multi-body Systems (MSS) who accordingly a system mechanics is stated for the collection of bodies have a high rotational and translational motions linked together via simple or complex joints.

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Since in kinematic analysis plots, we are not showing the additional length of swing arm, i.e. the wheel axle point, but we are considering only the length between two pivots which is shown as dark line (OA) in the below Figure, the maximum travel of this point from trigonometry comes out to be around 40 mm. This can be verified in the results in later section.

Figure 1: Illustration of part of swing arm involved in four bar loop and the maximum travel of second pivot point 1.2.

Dynamics Analysis

Dynamic Analysis of restitution, the suspension is to be provided to link the masses into the motor, and a chain, and also added a variety of links esteem. I really want to be the same time. To

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determine the level of competition for this purpose I may be comforted Wiper what is the angular speed. This reciprocal motion so we can answer.

2. RESULTS 2.1.

Kinematics Result

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Figure 2: Angular positions of other links

Figure 3: Angular velocities of other links

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Figure 4: Linear velocities of other links

Figure 5: Coupler curve

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3. DISCUSSION Windscreen wiper mechanism of the bar of the circular motion of the motor converted to an intermittent rotation. A lever of a stop of the place, but for different arms and other on the contrary. Kinematic analysis and the results presented in figure 10 shows clearly that links traveled approximately 40 mm 2, which the analysis section. 11 we can see in the figure, the cornerstone, who, however, this is nearly linear, but the trend is continually changing positions. The angular velocities of about 10 degrees, later changed sharply, as is evident from the fact that in Figure 12 linear velocity. Figure 14, which shows the direction unite travels about 5 mm-50 in that area, he makes the trip in 10 out of 5 mm. And thus required to be compressed spring is about 51 mm.

REFERENCES [1]. http://blistergearreview.com/recommended/suspension-101-designs [2]. http://www.bikeroar.com/tips/a-beginners-guide-to-mountain-bike-suspension-design [3]. https://en.wikipedia.org/wiki/Bicycle_suspension [4]. https://www.pinkbike.com/news/Diamondback-Prototype-DH-Bike-2011.html [5]. https://dirtmountainbike.com/features/buyers-guide-wheel-size-mountain-bike.html

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APPENDICES (MATLAB Analysis Code) function [t,z,r_PO] = windshieldwiper(n,npathpoints,lengths,omega) % wattLinkage - integrate the equations of motion for a Watt Linkage and % animate % % [t,z,r_PO] = winshieldwiper(n,npathpoints,lengths,omega) integrates the % equations of motion for a 3 bar Watt linkage and animates the motion of % the system over n cycles (one cycle is defined as a full sweep top to % bottom). npathpoints determines the number of trajectory points to plot % (Inf by default, for all). lengths is an optional 3 element array of % linkage lengths ([3,1,3] by default). omega is the angular rate in % radians per second (0.5 by default). The returned values are the % intergrator outputs (t and z) and the position of the center of the % intermediate bar. % % Example % % animate system over 10 cycles % wattLinkage(10); % %animate asymmetric linkage % [t,z,r_PO] = wattLinkage(5,[],[5 1 2]); % Written by Dmitry Savransky 21 May 2007 %check inputs if nargin == 0,error('You must input a number of cycles to simulate.');end if ~exist('npathpoints','var') || isempty(npathpoints),npathpoints=Inf;end if ~exist('lengths','var') || isempty(lengths) || numel(lengths) ~= 3 %linkage lengths l1 = 3; l2 = 1; l3 = l1; else l1 = lengths(1); l2 = lengths(2); l3 = lengths(3); end if ~exist('omega','var') || isempty(omega), omega = -0.5; end %initial conditions z0 = [0,0,0]; t = 0; z = z0; %calculate trajectory for n cycles for j=1:n [t1,z1] = ode45(@wattLinkage_eq,t(end):1/25:t(end)+10,z(end,:),... odeset('RelTol',1e-12,'AbsTol',1e-12,'Events',@wattLinkage_event)); omega = -omega; t = [t;t1]; z = [z;z1]; end %calculate positions of all points tAB = z(:,1); tBC = z(:,2);

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tCD = z(:,3); r_PO = [l1*cos(tAB) + l2/2*sin(tBC),l1*sin(tAB) - l2/2*cos(tBC)]; r_B = [l1*cos(tAB),l1*sin(tAB)]; r_C = [l1*cos(tAB) + l2*sin(tBC),l1*sin(tAB) - l2*cos(tBC)]; %generate supports h = l2/5; s1 = [0,h/2,-h/2 0;0,-h,-h,0]; s2 = [s1(1,:)+l1+l3;s1(2,:)-l2]; %findmaximum axis area ax = [ min([-h/2,0;r_B;r_C]), max([l1+l3+h/2,0;r_B;r_C])]; ax = ax([1,3,2,4]); ax(3:4) = ax(3:4)*1.05; %animate figure(1) hold off for j = 1:length(t) %plot links plot([0,r_B(j,1)],[0,r_B(j,2)],'r',... [r_B(j,1),r_C(j,1)],[r_B(j,2),r_C(j,2)],'g',... [r_C(j,1),l1+l3],[r_C(j,2),-l2],'b','LineWidth',3) hold on %draw supports fill(s1(1,:),s1(2,:),'r') fill(s2(1,:),s2(2,:),'b') %plot track so far: plot(r_PO(max([j-npathpoints,1]):j,1),... r_PO(max([j-npathpoints,1]):j,2),'k--'); %set axes to proper values: axis equal; grid on; axis(ax); set(gca,'XTickLabel',[],'YTickLabel',[]) hold off; %pause for length of time step if j < length(t) pause(t(j+1)-t(j)); end end function dz = wattLinkage_eq(t,z) %z =[theta_AB,theta_BC,theta_CD] tAB = z(1); tBC = z(2); tCD = z(3);

end

dz = [omega;... (omega *l1*sin(tAB - tCD))/(l2*cos(tBC - tCD));... (-omega*l1*cos(tAB - tBC))/(l3*cos(tBC - tCD))];

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function [val,isterminal,dr] = wattLinkage_event(t,z) %terminate when tAB - tBC + pi/2 = 0 and tBC - tCD - pi/2 = 0 val = [z(1) - z(2) + pi/2*0.9,z(2) - z(3) - pi/2*0.9]; isterminal = [1,1]; dr = [0,0]; end

end

Controller:

System control motor:

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Input Signals:

Mechanical System Block:

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MSC.ADAMS Plant Mask:

Output Signals: 1. Torque

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2. Rotor velocity:

3. Voltage

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4. Intensity:

5. Reference Input

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