NATIONAL UNIVERSITY HO CHI MINH CITY
UNIVERSITY OF TECHNOLOGY
Project 1:
DESIGNING AN AUTOMATIC ACCESS
SEAT FOR THE DISABLED APPLY ON KIA
SEDONA
Instructor: Dr. Phạm Huy Hoàng
Students:
ID
1. Nguyễn Trường Sơn
2013290
2. Trần Ngọc Khánh
1852460
3. Lê Nguyễn Đăng Khoa
1852473
Instructor’s signature
Ho Chi Minh City, 12th June 2022
0
Contents
Introduction ................................................................................................................... 2
I.
1.
What is disability?....................................................................................................... 2
2.
Current situation......................................................................................................... 2
3.
Topic urgency ............................................................................................................. 7
4.
Aim of the project ....................................................................................................... 7
II.
Scope, working condition and technical requirements. .................................................. 7
1.
Car model and dimension ............................................................................................ 7
2.
Original seat dimension ............................................................................................... 9
3.
Working conditions and technical requirements ........................................................... 9
III.
3.1.
Working conditions ................................................................................................ 9
3.2.
Technical requirements: ........................................................................................ 10
Choosing plan and simplify the motion....................................................................... 10
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I. Introduction
1. What is disability?
Disability is any condition of the body or mind (impairment) that makes it more
difficult for the person with the condition to do certain activities (activity limitation)
and interact with the world around them (participation restrictions). There are many
types of disabilities, such as those that affect a person such as: vision, movement,
hearing, mental health, etc.
According to the World Health Organization, disability has three dimensions:

Impairment in a person’s body structure or function, or mental
functioning; examples of impairments include loss of a limb, loss of vision
or memory loss.

Activity limitation, such as difficulty seeing, hearing, walking, or problem
solving.

Participation restrictions in normal daily activities, such as working,
engaging in social and recreational activities, and obtaining health care and
preventive services.
2. Current situation
7.06% of Vietnam’s population has one or multiple disabilities. This corresponds
to more than 6.2 million people. There are 29.41% of this group have to deal with
movement disability, which reduce them in some very simple movement such as
entering the vehicle. In Vietnam, there are ramp system in buses helping disabled
person enter the bus.
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Figure : Bus ramp in Vietnam
Moreover, there are a lot of systems existing products in the world are used to help
disabled person enter the vehicle by mechanical or technology.
2.1.Sideway ramp
Figure 1: Sideway ramp
The ramp have a simle structure with only a ramp help the disabled person move
up or down to the vehicle. However, it have some drawbacks. One of the drawbacks is
that the ramps are either just be pulled out manually or motor-powered. This lead to the
inconvenience for user that doesn’t have anyone else around to provide assistance. The
ramp also have some uncomfortable features such as Space-consuming inside or
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outside, the ramp extends more than one and a half meter and will not fit tight road or
garage. It’s also make the vehicle become longer because large space to disabled enter
or leave the vehicle. Moreover, the ramp connects the vehicle floor with the ground,
forming an incline that making it difficult for the elders to roll forward up into the
vehicle.
2.2.Back seat ramp
Figure 2 Backseat ramp
A ramp places backward to the rear end of the vehicle while increasing the length
of the ramp, making it less-steep but requires a re-work on the trunk. The ramp can be
folded, slide underneath the car via a chamber or internal extension, of which has its
own benefits and flaws. These types of ramp will be less steep and will not intercept
with the short distance with the sidewalk, but will be much significant in length through
the rear end of the vehicle.
2.3.Turny seat
The turny seat is a seat lift that moves the car seat completely outside the vehicle
and lowers it down to your desired level by remote control. This makes it easier for you
to sit down or transfer from a wheelchair. Once you're seated, push a button and the
Turny Evo will lift you inside or outside the car.
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Figure 3 Turny seat
2.4.Mechanical arm extension grabber and Chair topper
A combination of a crane-transporting system to grab a person and load them
into the original seat, then a “topper” will unfold and release a chain with hook that can
be attach to the chair. The wheelchair then be carried upward onto the car’s top and
secure within a firm box. This technique is old-school, cheap and reliable, but the one
handicapped is not 100% independent, sometimes the chair can be difficult to store
away or the person having trouble getting in the car themselves.
Figure 4: Chair toper
2.5. 2-Dimension lifter
This is a well-rounded system that have: +High loading capacity +Fast and easy
to transfer +Affordable and not space consuming. But nonetheless, having issue with
pave way and sidewalk distance once again. The platform cannot be rotate, the
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wheelchair on top of this platform also has constrained movement and can not rotate to
the front.
Figure 5 2D wheelchair lifter
2.6.All-terrain-conversion (ATC) lift
Similar to 2-dimensional lift, this system has all of the points. The only difference
is that this system can rotate on its axis to fit the road or a pave way without any trouble.
45o turn can help guiding the wheelchair to the correct position and also making it easier
to get out of the vehicle. The ATC lift may consume quite much space due to the heavy
duty piston circuit and rotational axial central crane.
Figure 6 ATC 3D/ diagonal lifter
2.7.Conclusion
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Compare to many products we introduced above, we choose the turny seat without
lowering or uppering the seat. This seat require not much movement from the disabled
person, they do not need to step up to the seat. However, they still need support from
people to take away the wheelchair.
3.
Topic urgency
Disability is part of the human condition. A lot of people suffered temporarily or
permanently impaired at some point in life or maybe whole their life, and those who
survive to old age will experience increasing difficulties in functioning.
Disability can be permanent and make one’s ability to function less efficient. For
those who suffer a loss of their walking ability, but since they already purchased a car
or a vehicle, the desire to drive on their own, eliminating dependency need to be
accomplished. Similarly, there are families having a member disabled that need to
travel together, having something to help them getting on the vehicle is wonderful
relief.
4.
Aim of the project
The aim of this project is to create a system which can help the disabilities to enter
automobiles easily with the help of the turny seat. This turny seat must be easy to use
for disabilities as well as support people, do not require much re-work on car body to
install the mechanism. When the seat is fully swinging, the distance between the foot
of disabled person and the ground must not exceed 205mm.
The users we are looking for using this system include 3 kinds of disabilities:
II.

People have problem with injuries, have to move with crutches.

People have long-term movement disabilities, have to use wheelchair

People have temporarily disabilities, using Occupational therapy wheelchair
Scope, working condition and technical requirements.
1. Car model and dimension
In this project, the vehicle we apply this system on KIA Sedona model, which is
slightly popular and reasonable price in Vietnamese market. The vehicle floor is not
too high to the ground so elevation and lowering mechanism is not necessary. This
model also have a sliding door, large space between driver row and middle row make
it easier to turning the mechanism without touching the door.
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Figure: KIA Sedona overview
The middle row of the vehicle include 2 main seat and one console seat as figure
below :
Main
Console
seat
seat
Main seat
Figure 10: The seat layout of KIA Sedona’s second row
Because the console seat can be removed so the spare space can be take advantage
to allow some extra extension in the future.
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Figure : KIA Sedona dimension
2. Original seat dimension
Figure : Seat dimension
3. Working conditions and technical requirements
3.1.Working conditions
-
A 150-kg person can sit in the system continuously for several hours.
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-
Under vibration on different road condition
3.2.Technical requirements:
-
Stable during disabled person seating on in several hours (about 12 hours).
-
Remain stable when the car is driving on medium rough terrain.
-
The system can be able to work at the voltage of 12V (electricity source
available on vehicle)
-
Easy to repair, replace the mechanical equipment and control the electric-
electronic system.
-
Include safety feature within the passenger seat (air bags, seat belt,..)
-
Swing angle of the chair is wide enough to help a disabled person enter the
seat easily.
-
The seat when fully extend must be able to withstand the load of a 75-kg
person sits unexpectedly and car seat.
-
The seat must be help the passenger get in easily into the vehicle and get out
completely from the vehicle.
-
The system must not occupy too much extra space.
-
The system must be simple in electrical and mechanism .
-
Vehicle does not need too much modification to install the seat mechanism.
So base on the plans above, the application range of the vehicle as well as the
technical requirement we choose the swivel turny seat mechanism.
III. Choosing plan and simplify the motion
With the swivel turny seat mechanism we have two option:
1. Hanged actuator and seat ( the actuator module located at the back of the
seat )
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The hanging actuator and seat model
Structure analysis:
We denote the schematic diagram of the structure above:
C
C’
A
B’
B
D
Figure 11: Schematic diagram of the auto access seat mechanism
Because the motion of the seat is linear movement and rotational simultaneously
so we have to subtract the length of the seat edge to the seat’s center. As the center of
the rotation of the seat is located at the back of the seat.
When the system operate the following component have :
-
The swivel bar AC will receive the rotation motion with center A
-
B point will have linear movement in which length AB will extend ( B move
further away from A)
-
Bar CC’B will receive linear and rotational motion with center B with C point
is located on the two rotation bar and also have a linear motion so the point C will
have a eclipse trajectory.
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We only need the chair to rotate 90 degree from it original position so this
structure’s linear trajectory heavily depend on the length of the swivel bar AC ( the
shorter the length the chair will rotate faster reach 90 degree angle earlier therefore
the linear trajectory will be lower )
We consider the our structure ( 4 bar linking structure ) from planar projection :
Figure 12: The swivel turny seat general layout design
This type of model have the following advantages and disadvantages :
Advantages :
 Good vertical stability
Disadvantages:
 Structure contain a lot of shear stress at some position
 Passenger can not adjust the seat angle
 The structure occupy too much space in one side .
Technically this structure can be improve some problem about shear stress ( use
bigger bolt, apply supporting fixture ) but the passenger’s comfort is not ensure and
the occupation of the actuator in one side is not good for space management in the
vehicle. So this structure is not suitable for the demanded requirement.
But the 4 bar linking structure still can be consider for further improvement for the
other type of layout.
2. Seat on actuator ( the actuator is bolted on the floor and under the seat )
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The turny swivel seat with actuator under model
(or seat on actuator model )
This structure is also based on the 4 bar linking structure but the swivel have some
modification to reduce the size as well as the function and shape. Moreover this
structure reduce a lot of critical position ( shear stress position ) most of the
component will have compression and strain when operate this will enhance the
stability when the vehicle moving .
We can define the structure as the schematic diagram below :
C’
C
limiter
A
limiter
F
B’
D
The schematic diagram of the seat on actuator model
Structure analysis :
With this structure when the actuator start the motion of the structure can be
divided by 2 stages :
Stage 1 : The bar BC have linear motion until the limiter F on sliding bar FC
touch the sliding block A .
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B
Stage 2 : When the limiter F touch the sliding block A, the BC bar will have
linear motion and rotational motion simultaneously in which B point will only have
linear motion and point C will receive the circular rotational motion with center B
respectively therefore point C will have eclipse trajectory respect to other stationary
point.
With this structure the mechanism is more compact and also allow more linear
movement before the seat is completely rotate 90 degree as the bar FC need to move
slide on the A block before the limiter
Hit the sliding block A and form a swivel to make BC bar rotate. We can adjust
the length of the pre-rotation linear motion by adjusting the distance between limiter F
and sliding block A.
From the motion analysis above we can study the advantages and disadvantages of
the seat on actuator model :
Advantages:
 More compact
 More linear trajectory allow the passenger to lean out further from the original
position
 Linear movement length before rotation occur can be adjusted
 The seat angle can be adjusted
Disadvantages :
 The extrusion length ( DB ) is longer and the offset support of the seat will
cause deflection problem increase
 During collapse the seat holder BC could get collide with the body of the
actuator ( due to high deflection, unexpected object stuck in, etc.... )
 The seat may need to install not align with other seat in a row if the vehicle’s
door frame collide with the seat rest.
With the followed abstract above we can consider some disadvantage to resolve or
can be accepted this model will be put into design for the project.
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