SIX DEGREES OF FREEDOM INTEGRATION DEVICE
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This paper discusses the design of a novel six degrees of freedom integration device for aligning heavy conical and cylindrical articles essential for manufacturing. The mechanism enables three linear motions (vertical, longitudinal, lateral) and three rotational motions (pitch, yaw, roll) to ensure stability and precise alignment during assembly processes. Ergonomics and aesthetics were also considered in the design, which incorporates toggle jacks, cross slides, and rollers to support the movement of heavy payloads.
![Pranav Suryawanshi, Soham Wadnap, Ruchita Pedram, Nikhil Wakode, Prof. Ajaj Attar
http://www.iaeme.com/IJMET/index.asp 194 editor@iaeme.com
The conical article is a very heavy device (say weighing up to 500kgs). It has to
be precisely aligned with the main article (cylindrical) which is placed on a stationary
support on the ground. Due to the large weight of the payload it becomes very
difficult for the operators to integrate it with the main articles. Various problems arise
and a proper mechanism satisfying the purpose satisfactorily is required. A number of
problems had to be tackled arising from this process of integration. An alternative
process was required to overcome these problems, also it was effective to compare old
and the new process. It seems to be very challenging and new and innovative methods
have been thought about. It will be a great help if a more effective and efficient
alternative is being made.
2. PROBLEM STATEMENT
Any launch vehicle (rocket/missile) is usually a cylindrical body having number of
segments like propulsion, navigation & control, payload etc.
These sections are to be precisely located, oriented and assembled at the site of
launch. The payload will be stored separately at other location and is required to be
integrated with the launch vehicle on the launcher. This device must take care of six
degrees of freedom (three rotational and three translational).
The project will comprise of conceptualization of various alternatives, finalization
of suitable concept, detailed design including mechanism design, prototype realisation
and testing and final recommendations for actual system
3. LITERATURE REVIEW
3.1. Eureka: A New 5-Degree-of-Freedom Redundant Parallel Mechanism
with High Tilting Capabilities [1]
It is a new parallel mechanism which provides 5 motions .The five desired motions
include three translational and two rotational motions. High tilting angles (about first
axis and whole revolution about the following axis)is achieved by this device . This is
achieved with the help of actuation redundancy and specific travelling . . Kinematic
models are derived. Due to its particular shape the geometrical model is also derived
with ease. The paper explains plot of well conditioned workspace and practical
designs, free of self-collisions.
3.2. Kinematic Analysis Of a Translational 3-Dof Tensegrity
Mechanism[2]
It presents a novel three-degree-of-freedom mechanism based tensegrity architecture.
A cable driven mechanism is there and it exhibits three-dimensional translational
motion. Analytical solutions to the direct and inverse kinematic problems are
generated based on the geometry as well as statics of the mechanism. The boundaries
of the reachable Cartesian workspace are produced based on maintaining valid
tensegrity configurations and requiring the actuated cables to be in tension. Low
inertia, relatively large workspace volume and the movement produced by the
mechanism assure for high speed applications such as pick and place operations.](https://image.slidesharecdn.com/ijmet0703018-2-160729095513/85/SIX-DEGREES-OF-FREEDOM-INTEGRATION-DEVICE-2-320.jpg)
![Pranav Suryawanshi, Soham Wadnap, Ruchita Pedram, Nikhil Wakode, Prof. Ajaj Attar
http://www.iaeme.com/IJMET/index.asp 196 editor@iaeme.com
5. SAMPLE CALCULATIONS [3]
5.1. Calculations for roller pin
By flexure formula, we have
i.e.
For circular cross-section,
Therefore
Stress induced,
N/mm2
Zinduced =
=
Zinduced = 548.3636 mm3
Thus,
Where,
σ = bending stress
I = moment of inertia
M = bending moment (here, 17547.6375)
y = location of centroid](https://image.slidesharecdn.com/ijmet0703018-2-160729095513/85/SIX-DEGREES-OF-FREEDOM-INTEGRATION-DEVICE-4-320.jpg)
![Six Degrees of Freedom Integration Device
http://www.iaeme.com/IJMET/index.asp 199 editor@iaeme.com
5.6 Final Results
Table 1
Sr. no Component Dimensions
1. Roller pin d= 20mm
2. Toggle jack l= 127mm, b1=24mm, t1=12mm
3. Bottom channel frame ISJC 150, b=50mm, h=150mm
4. Shaft d= 50mm
Here:
d: diameter
l: link length, b1: link breadth, t1: link thickness
Other values hold their usual meanings.
6. CONCLUSION
Thus the six degrees of freedom have been achieved amongst which three being
translational and three being rotational. Vertical motion has been successfully
achieved by means of the toggle jack. The rotational motion has been achieved by
means of rollers, lateral motion by the cross slides and the horizontal traverse by rails
and wheels. The other motions like yawing and pitching are achieved by varying the
inputs of these parameters needed to provide these motions precisely and safely. Thus
all motions are achieved under safe and precise considerations so as to assemble the
required parts.
ACKNOWLEDGEMENT
We would like to acknowledge our sincere gratitude to project supervisor Mr. Anil
Chavan for his valuable suggestions and encouragement. Also our sincere thanks to
administrative and technical staff members of the Department who have been kind
enough to advice during our work at SKNCOE Pune.
REFERENCES
[1] Sébastien Krut, Olivier Company, Sani Rangsri, François Pierrot, Eureka: A New
5-Degree-of-Freedom Redundant Parallel Mechanism, Intl. Conference on
Intelligent Robots and Systems, IEEE, pp.3575-3580, 2003.
[2] Chris A. Mohr, Marc Arsenault, Kinematic Analysis of A Translational 3-Dof
Tensegrity Mechanism, Transactions of the Canadian Society for Mechanical
Engineering, 35(4), 2011
[3] R. S. Khurmi, J. K. Gupta, A textbook of machine design, Eurasia publishing
house Pvt. ltd.
[4] Akash Sood and Padam Singh, Prof. Ajaj Attar Analysis of Space Frame of
Formula Sae at High Speed with Ergonomic and Vibrational Factors.
International Journal of Mechanical Engineering and Technology, 6(11), 2016,
pp. 202–212.
[5] Jan-Cristian Grigore and Nicolae Pandrea, Calculation of The Undetermined
Static Reactions For The Articulated Plan Quadrilateral Mechanism.
International Journal of Mechanical Engineering and Technology, 4(3), 2013,
pp. 400–408.](https://image.slidesharecdn.com/ijmet0703018-2-160729095513/85/SIX-DEGREES-OF-FREEDOM-INTEGRATION-DEVICE-7-320.jpg)
SIX DEGREES OF FREEDOM INTEGRATION DEVICE
- 1. http://www.iaeme.com/IJMET/index.asp 193 editor@iaeme.com International Journal of Mechanical Engineering and Technology (IJMET) Volume 7, Issue 3, May–June 2016, pp.193–199, Article ID: IJMET_07_03_018 Available online at http://www.iaeme.com/IJMET/issues.asp?JType=IJMET&VType=7&IType=3 Journal Impact Factor (2016): 9.2286 (Calculated by GISI) www.jifactor.com ISSN Print: 0976-6340 and ISSN Online: 0976-6359 © IAEME Publication SIX DEGREES OF FREEDOM INTEGRATION DEVICE Pranav Suryawanshi, Soham Wadnap, Ruchita Pedram, Nikhil Wakode, Prof. Ajaj Attar Mechanical Engineering Department, Smt. Kashibai Navale College of Engineering, Pune–MS ABSTRCT This paper presents a novel six degrees of freedom mechanism to integrate conical article with the cylindrical article which are large and heavy. The six desired motions include six linear motions and six rational motions. The linear motions are vertical, longitudinal and lateral. The vertical motion is achieved by toggle jack, longitudinal by wheel and rail assembly and the lateral motion is achieved by cross slides. The three rotational motions namely pitch, yaw and roll are achieved by simultaneous movement of toggle jacks, simultaneous movement of cross slides and rollers respectively. It is designed in such a way that it sustains the weight of the heavy articles and also prevents slipping and toppling of the conical article. This approach helps to satisfy and fulfil the goal of aligning the main article flange to the conical article flange for further bolting. The mechanism is designed keeping in mind factors like ergonomics and aesthetics. Key words: Six Degrees of Freedom Mechanism, Linear Motion, Rotational Motion, Toggle Jack, Cross Slide, Ergonomics, Aesthetics Cite this Article: Pranav Suryawanshi, Soham Wadnap, Ruchita Pedram, Nikhil Wakode, Prof. Ajaj Attar, Six Degrees of Freedom Integration Device. International Journal of Mechanical Engineering and Technology, 7(3), 2016, pp. 193–199. http://www.iaeme.com/currentissue.asp?JType=IJMET&VType=7&IType=3 1. INTRODUCTION Since early ages mankind has been struggling with large and long structures or objects where the question of how it would be manufactured aroused. Then the thought of integrating parts came into action where the body would be made in parts and then assembled. Heavy structures became the integral part of this plan. Manufacturing took turns under all types of economic systems. In a free market economy manufacturing was usually directed towards the mass production of parts .Modern manufacturing includes all intermediate processes required for the production and integration of a product's components.
- 2. Pranav Suryawanshi, Soham Wadnap, Ruchita Pedram, Nikhil Wakode, Prof. Ajaj Attar http://www.iaeme.com/IJMET/index.asp 194 editor@iaeme.com The conical article is a very heavy device (say weighing up to 500kgs). It has to be precisely aligned with the main article (cylindrical) which is placed on a stationary support on the ground. Due to the large weight of the payload it becomes very difficult for the operators to integrate it with the main articles. Various problems arise and a proper mechanism satisfying the purpose satisfactorily is required. A number of problems had to be tackled arising from this process of integration. An alternative process was required to overcome these problems, also it was effective to compare old and the new process. It seems to be very challenging and new and innovative methods have been thought about. It will be a great help if a more effective and efficient alternative is being made. 2. PROBLEM STATEMENT Any launch vehicle (rocket/missile) is usually a cylindrical body having number of segments like propulsion, navigation & control, payload etc. These sections are to be precisely located, oriented and assembled at the site of launch. The payload will be stored separately at other location and is required to be integrated with the launch vehicle on the launcher. This device must take care of six degrees of freedom (three rotational and three translational). The project will comprise of conceptualization of various alternatives, finalization of suitable concept, detailed design including mechanism design, prototype realisation and testing and final recommendations for actual system 3. LITERATURE REVIEW 3.1. Eureka: A New 5-Degree-of-Freedom Redundant Parallel Mechanism with High Tilting Capabilities [1] It is a new parallel mechanism which provides 5 motions .The five desired motions include three translational and two rotational motions. High tilting angles (about first axis and whole revolution about the following axis)is achieved by this device . This is achieved with the help of actuation redundancy and specific travelling . . Kinematic models are derived. Due to its particular shape the geometrical model is also derived with ease. The paper explains plot of well conditioned workspace and practical designs, free of self-collisions. 3.2. Kinematic Analysis Of a Translational 3-Dof Tensegrity Mechanism[2] It presents a novel three-degree-of-freedom mechanism based tensegrity architecture. A cable driven mechanism is there and it exhibits three-dimensional translational motion. Analytical solutions to the direct and inverse kinematic problems are generated based on the geometry as well as statics of the mechanism. The boundaries of the reachable Cartesian workspace are produced based on maintaining valid tensegrity configurations and requiring the actuated cables to be in tension. Low inertia, relatively large workspace volume and the movement produced by the mechanism assure for high speed applications such as pick and place operations.
- 3. Six Degrees of Freedom Integration Device http://www.iaeme.com/IJMET/index.asp 195 editor@iaeme.com 4. METHODOLOGY 4.1. Working For the precise alignment of the two articles, they must be given all the degrees of freedom mentioned. Various alternatives have been considered and the finalised concept is as follows. The rolling motion is given by two drivers and two follower rollers. The concerned article will be mounted on these rollers with a metal strip fitting on the rollers. These have tested for load bearing capacity such that they are sufficient enough to bear the load of the conical object and successfully rotate it to certain degree sufficient enough for bolting. The rollers, one driver and one follower, are mounted inside two C-sector curved beams each. The C-sectors being placed at calculated distances providing stability as well as support. Each curved beam is supported on an I-beam with the means of the same I-columns. Vertical motion is given to this I-beam (the top frame) with the help of a toggle jack with a capacity 2452.5 N. The toggle jack is mounted on the middle frame made of two C-sectors. Two such toggle jacks have been provided on two middle frames .C-sector thus doubling the chances of safety and increasing capacity. Varying the motions of the toggle jacks simultaneously results in achieving pitching, a desired motion. To overcome horizontal misalignment of the axes of the two articles, there needs to be freedom of lateral movement. This movement is provided by cross slides. The bottom rail is attached to the bottom frame, a composite of two C-beams, and the top rail is attached to the middle frame. The top rail of cross slide slides over the bottom rail cross slide. The part in contact is fit with Teflon strips to minimize friction and give lateral movement. The cross slides are moved by means of a power screw. The nut of power screw is fixed to the bottom frame and the screw itself fits in a collar fit with the middle frame. This gives a relative motion when the screw is rotated. A total of four cross slides provides this motion with ease such that there are two on each side and a total of two power screws. Thus varying their motion will also result in achieving yawing motion. To move the cylindrical part closer to the conical part in longitudinal motion, rail system will be used. The device is rested on these rails on wheels by rotating the axle of the common shaft wheel, longitudinal movement can be achieved. So all the six degrees of freedom have been covered by the device. 4.2. Diagram Figure 1 Front View of The Integration Device
- 4. Pranav Suryawanshi, Soham Wadnap, Ruchita Pedram, Nikhil Wakode, Prof. Ajaj Attar http://www.iaeme.com/IJMET/index.asp 196 editor@iaeme.com 5. SAMPLE CALCULATIONS [3] 5.1. Calculations for roller pin By flexure formula, we have i.e. For circular cross-section, Therefore Stress induced, N/mm2 Zinduced = = Zinduced = 548.3636 mm3 Thus, Where, σ = bending stress I = moment of inertia M = bending moment (here, 17547.6375) y = location of centroid
- 5. Six Degrees of Freedom Integration Device http://www.iaeme.com/IJMET/index.asp 197 editor@iaeme.com Z = section modulus d = diameter of roller pin σall = allowable bending stress (0.66*Syt) Syt = tensile yield strength of M.S. (240 N/mm2 ) f.s = factor of safety (5) 5.2. Design of Toggle Jack and link length equal to 127mm (mild steel) (co-efficient of friction) We know that W= 250 kg = 250*9.81 = 2452.5 N F = W/2tan W1 = 2F effort required to rotate the screw P = = Torque required to rotate the screw shear stress in the screw due to torque direct tensile stress in the screw Maximum principal (tensile) stress, According to Rankine’s formula, buckling load (Wcr)
- 6. Pranav Suryawanshi, Soham Wadnap, Ruchita Pedram, Nikhil Wakode, Prof. Ajaj Attar http://www.iaeme.com/IJMET/index.asp 198 editor@iaeme.com 5.3. Bottom Channel Frame σ = Bending Stress Y = Moment of Inertia M = Bending Moment Y = Section Modulus Diag.1 Line Diagram For The C-Channel 5.4 Shaft Bearing Selection Deep groove ball bearing, which is easily available in the market and has a high stability has been selected. The shaft diameter is 50 mm, from this diameter, using design data book selecting series 6010 bearing 5.5 Design of Shaft Diag.2 Line Diagram For Shaft I = Z = Z =
- 7. Six Degrees of Freedom Integration Device http://www.iaeme.com/IJMET/index.asp 199 editor@iaeme.com 5.6 Final Results Table 1 Sr. no Component Dimensions 1. Roller pin d= 20mm 2. Toggle jack l= 127mm, b1=24mm, t1=12mm 3. Bottom channel frame ISJC 150, b=50mm, h=150mm 4. Shaft d= 50mm Here: d: diameter l: link length, b1: link breadth, t1: link thickness Other values hold their usual meanings. 6. CONCLUSION Thus the six degrees of freedom have been achieved amongst which three being translational and three being rotational. Vertical motion has been successfully achieved by means of the toggle jack. The rotational motion has been achieved by means of rollers, lateral motion by the cross slides and the horizontal traverse by rails and wheels. The other motions like yawing and pitching are achieved by varying the inputs of these parameters needed to provide these motions precisely and safely. Thus all motions are achieved under safe and precise considerations so as to assemble the required parts. ACKNOWLEDGEMENT We would like to acknowledge our sincere gratitude to project supervisor Mr. Anil Chavan for his valuable suggestions and encouragement. Also our sincere thanks to administrative and technical staff members of the Department who have been kind enough to advice during our work at SKNCOE Pune. REFERENCES [1] Sébastien Krut, Olivier Company, Sani Rangsri, François Pierrot, Eureka: A New 5-Degree-of-Freedom Redundant Parallel Mechanism, Intl. Conference on Intelligent Robots and Systems, IEEE, pp.3575-3580, 2003. [2] Chris A. Mohr, Marc Arsenault, Kinematic Analysis of A Translational 3-Dof Tensegrity Mechanism, Transactions of the Canadian Society for Mechanical Engineering, 35(4), 2011 [3] R. S. Khurmi, J. K. Gupta, A textbook of machine design, Eurasia publishing house Pvt. ltd. [4] Akash Sood and Padam Singh, Prof. Ajaj Attar Analysis of Space Frame of Formula Sae at High Speed with Ergonomic and Vibrational Factors. International Journal of Mechanical Engineering and Technology, 6(11), 2016, pp. 202–212. [5] Jan-Cristian Grigore and Nicolae Pandrea, Calculation of The Undetermined Static Reactions For The Articulated Plan Quadrilateral Mechanism. International Journal of Mechanical Engineering and Technology, 4(3), 2013, pp. 400–408.