brake

1. A COMBINED PEDAL FOR BRAKE AND ACCELERATOR
ABSTRACT
It has been reported that some automobile accidents are caused by mistakenly pressing down
the accelerator, when the intention was to press down the brake. Recordings of an electro-
goniometer at the right knee joint on some subjects showed that upon receiving a fright due to
a sudden loud noise or some emergency situations the knee initially became taut. It can
therefore be supposed that some drivers have difficulty in removing their foot from the
accelerator pedal and transferring it to the brake pedal quickly. So this design makes
ergonomically fit for user that enables reducing shifting time between accelerator and brake.
Combination of brake and accelerator pedal is very much useful for driver.

2. INTRODUCTION
This is a combination accelerator and brake control mechanism where in there is a single pedal
serving both as the charge control and the brake control. The single pedal is pivoted on a pivot
fixed in a base, the pedal extending through the vehicle floor board hence it is single pedal
pivotally mounted on one end of a lever, the other end of which is adapted to be pivotally
mounted on the floor of the vehicle. The heel-engageable portion is connected by a link to the
throttle-operating lever. A brake-operating lever is pivotally mounted on the vehicle and
connecting rod pivotally connects such lever which attached with push rod of master cylinder.
Pressing with the foot on the superior or upper part of the single pedal controls the charge to
the vehicle motor, pressing with the foot on the lower or inferior part of the pedal controls the
brakes of the vehicle. A see-saw rod contacts directly or indirectly with the ends of both the
vehicle gas control rod or the brake control rod, and the motion of the pedal pressed down on
its top end acting through the see-saw rod moves the charge control mechanism from neutral
position to gas control position, and pressing the lower end of the pedal actuates the brake
control mechanism. Thus, the action of the human foot with this device is very similar to that
with the customary two pedal control, for the usual accelerator is usually operated by toe
pressure and the brake pedal is usually operated by heel pressure.

3. LITERATURE REVIEW
Antonio Frontcra Pascual: The subject of the present descriptive memorandum is a combined
accelerator and brake pedal control systemfor automobiles. At the present time, as is known,
automobiles are equipped with independent pedal controls for operating the accelerator and
the brake.
Rickard Nilsson: This study by Rickard Nilsson is focusing on adaptability of new invention by
drivers because drivers actually face lot of problems in adapting new method of accelerating
and braking using combined brake and accelerator pedal instead of separate pedal.
Charles Rabin: The present invention generally relates to a control device for automobiles or
similar type vehicles having an internal combustion engine with a carburetor normally provided
with a throttle valve for controlling the inlet of a fuel and air mixture in which there is
incorporated a construction providing for closing of the throttle valve when the brakes of the
vehicle are applied and providing for opening of the throttle valve when the brakes are
released.

4. OBJECTIVES
Design, Analysis and Testing of single pedal brake accelerator mechanism to reduce pedal
shifting time and to reduce the possibility of misapplication of pedal or bad hit of pedal.
The major objectives of single pedal brake-accelerator mechanism are:
1. Design of single structure which consists of two system
i.e. braking systemand acceleration system.
2. Combining the braking pedal and accelerator pedal mechanism on single pivot.
3. Arranging the motions of two different pedals so that can be handled by same foot.
4. Motions of two pedals should not interfere with each other.
5. Working of two systems should be separate and should not interfere with each other.

5. CONSTRUCTION
The main components used in this project are base frame, rod, wires, eliminator, motor, limit
switch(on/off) and cut off limit switch, spring(torsion and tensile). The pedal consist of two
pivot points 1 and 2. The pivot point 1 and 2 used for acceleration and braking. For acceleration
pivot point 2 is used and for braking pivot point 1 is used. The pedal is made up of Mild steel.
Base frame
A frame is often a structural systemthat supports other components of a physical construction
and/or steel frame that limits the construction's extent. The frame can with stand all the other
components like motor, limit switch, cut off valve and other rods etc.. The frame should have
the maximum load withstand capacity. The frame is joined by using arc welding.
Base frame

6. Tensile and Torsion spring
A spring is a flexible elastic object used to store mechanical energy. Torsion spring is a spring
that works by torsion or twisting. It is used for automatic retrieving of pedal during acceleration
(Feet Moment) Tensile spring is used for breaking (Leg Moment)
Torsion Spring Tensile Spring
Pedal
Automotive the pedal used by the driver of a vehicle to operate the brakes and acceleration.
Examples from the Web for brake pedal and acceleration pedal. The controls appeared to be
functioning smoothly enough. In this project we can use single pedal for braking and
acceleration to quickly stop the vehicle. The pedal is joined by using arc welding.

7. A combined and pedal mechanism is designed to function as both brake and accelerator, which
can be adopted by driver quickly and effortlessly. This new mechanism enables the driver to
control acceleration and braking using one feet, which will lead to reduction in stopping
distance, misjudgement and ultimately decrease in number of road accidents that may happen
each day.
Limit switches (on/off and cut off):
ON/OFF Limit Switch supply the current to motor. ON/OFF Limit Switch is used to actuate the
motor during acceleration. CutOFF Limit Switch cut the current supply to the motor. CutOFF
Limit Switch is used to stop.
ON/OFF Limit Switch and Cut OFF Limit Switch

8. DC motor
Here the motor is run by using the limit switch .When the limit switch is ON the motor is run.
when the cut off switch is actuated the motor is stopped. This technique is used for solar cart
vehicle.
DC Motor
Eliminator
Eliminator is used for converting the power supply from AC to DC voltage current. It also varies
the voltage between 5v to 12v. It is a device powered by an electrical source other than a
battery. It may be used by a second device designed to be powered by batteries.

9. Eliminator
Connecting rod
The rod which is used to actuate the CuttOFF limit switches. The connecting rod is attached to
the pedal. When pedal is pressed during braking .The connecting rod moves forward and hit the
CuttOFF limit switch and motor stops.
Connecting Rod

10. CONNECTIONS
There are two terminal positive and negative.
In which the positive terminal from the rectifier is connected to the ON/OFF limit switch and
that ON/OFF limit switch is connected to the CUTOFF limit switch and this CUTOFF limit switch
is connected to motor.
In other side the negative terminal is connected to the motor from rectifier. The current is
passed to the ON/OFF limit switch when this limit switch is ON. The current is passed to the
CUTOFF limit switch.
When the CUTOFF limit switch is not actuated the power is passed to motor and the motor
runs.
When the CUTOFF limit switch is actuated, the power is not passed to the motor and the motor
is stopped.

11. MECHANISM
In order to eliminate such kind of problems, A COMBINED PEDAL MECHANISM is designed to
function as both BRAKE and ACCELERATOR, which can be adopted by driver quickly and
effortlessly.
This new mechanism enables the driver to control acceleration and braking using one feet,
which will lead to reduction in stopping distance, misjudgement and ultimately decrease in
number of road accidents that may happen each day.

12. Different views of 3D modelled mechanism
(a)
(b)

13. METHODOLOGY
The design of new mechanism aims, to provide a pedal that applies the brakes instantaneously
and also permits the operation of accelerator with the same foot. In other words, the vehicle
must not accelerate at the time of braking and at the time of acceleration vehicle must not
decelerate or stops.
The design of mechanism was prepared on 3D modelling software CATIA V5 R20, after that, a
working model is prepared using mild steel (AISI 1018) as material. It consists of a base plate
say, 3mm thickness on which the whole mechanism is to be constructed. The lever is mounted
over the base plate which is free to rotate in any direction, its forward movement is controlled

14. by stroke of master cylinder and backward movement is controlled by two helical tension
springs arranged in parallel, which helps the lever to come back in original position. In addition,
another purpose of spring is to restrict the movement of lever during throttling. At the top of
the lever 2nd pivot is provided on which the foot lever is clamped which is also free to rotate in
any direction.
The above figure represents drawing of the combined pedal mechanism, which illustrates all
three views for better understanding. It shows foot lever is directly attached to pivot point 2
using a M8 half threaded bolt, which gives angular moment to foot lever. Similarly, pivot point 1
is created on base plate, which enables linear movement of push rod into the master cylinder.
MASTER CYLINDER

15. The master cylinder, also known as the master brake cylinder, converts the pressure on the
brake pedal to hydraulic pressure by feeding brake fluid into the brake circuit and controlling
this according to the mechanical force.
FUNCTION OF MASTER CYLINDER
The master cylinder, also known as the master brake cylinder, converts the pressure on the
brake pedal to hydraulic pressure by feeding brake fluid into the brake circuit and controlling
this according to the mechanical force. Master brake cylinders are used both in disc brakes and
drum brakes.
Due to statutory provisions, a car must be equipped with two separate brake circuits. So-called
tandem master cylinders generate the hydraulic pressure for the two separate brake circuits. In
the event of one brake circuit failing, the brake pressure builds in the other brake circuit still
intact.
When the driver presses the brake pedal, the power from his/her foot on the pedal is
transmitted to the pressure piston. The piston is pushed towards the brake line.
In master cylinders in older vehicle models, the piston collar passes over the compensating
bore, the pressure chamber is closed and braking force is generated. When the driver now
releases the brake pedal, the pressure piston, supported by a spring, is returned to its original
position. Brake fluid then flows into the main cylinder, so that if the pedal is pressed again
immediately, the brake pressure is increased.
COMBINED PEDAL FOR BRAKE AND ACCELERATION SYSTEM
The pedals mounted at the centre of a vertically displaceable pivot. The ends of the pedal
serves as accelerator and brake. To accelerate driver, pivot the pedal while to Brake driver,
push the entire pedal mechanism forwards. So, Accelerating is a feet movement and, while
braking comes from extending whole leg. A driver can switch from acceleration to braking
instantly, just by pressing the combined pedal forwards.

16. A few potential disadvantages with the combined pedal may be noted. One significant problem
is the risk for confusion when the person that is familiar with separate pedals for the brake and
accelerator must relearn these actions when required to use the combined pedal. The most
obvious danger is that drivers will move their foot away from the pedal, particularly in
emergency situations. A corresponding problem can arise when the driver, who is accustomed
to the combined pedal, returns to the systemof separate pedals. In this latter case, the driver
stretches his out his or her leg during braking and hence inadvertently presses the accelerator
instead of the brake pedal.
A second possible hazard concerns an ergonomic problem. If the driver has difficulty in relaxing
because of concern for unintentional braking, physical tension and strain likely to occur.
The third imperilment is that the shortened reaction time in braking in combination with the
increase in flexibility can bring about what is known as the compensation phenomenon.
Concern has been most intense for problems associated with driver confusion. While an
individual probably face little difficulty to relearn, in that case it would be difficult to
recommend combined pedal, even though it is likely a better solution than traditional pedals.
At the introduction of the combined pedal system, the vehicle population would consist of
vehicles with divergent pedal systems for a considerable number of years. This inevitably would
entail a large number of hazardous traffic situations because drivers are continuously required
to switch between pedal systems.
Consequently, an initial controlled evaluation of combined brake-accelerator pedal should
focus on highlighting the eventual problems that may occur during the transition period
between the combined pedal and the conventional pedals. The purpose of the present study,
therefore, was to examine the potential transition problems as outlined earlier.

17. Different views of fabricated mechanism

18. (a)

19. (b)

20. WORKING MECHANISM
Acceleration
In order to accelerate, the foot lever rotates about pivot point 2(upper pivot point), the figure
shows the upper half of foot lever moves in downward direction and lower half of pedal moves
in upward direction i.e rotation of foot lever would be in anticlockwise direction. However, the
support is kept in stationary position, this resistance is achieved by using helical tension spring.
The main purpose of spring is to provide Resisting force to the support during throttling. Hence,
by using upper half of the foot, driver can accelerate the vehicle without actuation of brakes.
Braking
In order to brake , the foot lever and support both moves in linear direction such that, there
would be no acceleration of the vehicle. This is achieved by fixing the source (acceleration
cable) at the bottom end of the pedal near the heel rest. Therefore, the whole assembly (foot
lever, support) rotates about the pivot point 1 and spring comes in stretched position. On
releasing the pedal, the spring tends to come in original position due to spring action. Hence,
driver can decelerate or stop the vehicle without actuation of throttle

21. Neither acceleration nor Braking
In this condition foot of driver simply rests on foot lever, it does not cause either of the
function. The figure shows the positioning of foot, any further movement results in acceleration
or braking.

22. Advantages:
1. It takes longer to brake in an emergency with separate pedals. It takes at least 0.2 seconds
to move your foot from one pedal to the other and at 80 kilometers per hour this adds five
meters to your stopping distance.
2. Another problem with separate pedals is that it's there is possibility of hitting the wrong one.
A slight misjudgment when going for the brake, can lead to the accelerator being clipped,
causing a crash.

23. 3. One of these advantages is the instantaneous and natural control available by single foot
movement.
4. It reduces the use of handbrake and return of the car while driving on inclined road having
positive slope.
5. This combined pedal mechanism thus provides a driving control which permits the quick and
smooth transition from acceleration to braking, without needing to transfer the foot from one
pedal to another.
6. For physically challenged persons the pedal is more useful because they no need to change
their foot.
7. A systemto generate heat from Scheffler reflector consists of a number of subsystems and
components. However, it is easy to see what the entire systemdoes by specifying just a few
basic parameters.
8. The acceleration and brake can be done quickly. It will also used in electric motor vehicle.
LIMITATIONS
1. There is more force is required while apply a sudden brake to stop the vehicle.
2. It is difficult to operate the pedal during climbing on hills. To overcome that problem, we
should use handbrake. It will be uncomfortable to user.

24. CONCLUSION AND FUTURE SCOPE
With the above study we can conclude that this new mechanism results in avoiding
interference of braking during acceleration and vice versa.
Moreover, it is advantageous over conventional pedals. This combined pedal mechanism thus
provides a driving control which permits the quick and smooth transition from acceleration to
braking, without needing to transfer the foot from one pedal to another.
The rapid increase in number of vehicles on roads day by day, demands an exploration of such
mechanism to get rid of driver’s effort and reduce road accidents.
This innovative project will be useful for physically challenged person in future.

25. References
[1] Rickard Nilsson, 2002, Evaluation of combined brake-accelerator pedal, Accident Analysis
and Prevention, 34, pp. 175-183.
[2] http://www.google.com/patents/US3331479.
[3] V.B. Bhandari, “Design of Machine Elements”, Published by Tata McGraw hill Education
Private Limited, third edition copyright © 2010.
[4] Robert L. Jeffcoat, Andrew Jackson, Department of Mechanical Engineering and Applied
Mechanics University of Pennsylvania.,
[5] Uday.A.Bakshi, Mayuresh.V.Bakshi,, Department of Electronics Engineering, Electrical drives
and control.