1. Design of a Novel Foot Resting Mechanism
Coupled with Vehicle Dynamics and Controls
Sameer Shah, M V Bhaskara Rao,
Sir M. Visvesvarya Institute of Technology,
Bengaluru, INDIA

2. HIGHLIGHTS
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• Vehicle Controls
• Throttle System
• Muscle Fatigue
• Novel Foot Resting Mechanism & Initial Calibration Procedures
• Sensors’ Performance & Theoretical Proof
• System Integration & Working Methodology
• Pedal Operations & Servomotor Dynamics
• Prototype Details & Simulation Analysis
• System Compatibility & Future Applications
• Conclusion

3. Vehicle Controls
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Vehicle possesses various controlling elements such as throttle,
steering braking etc.
Throttle System regulates the throttle plate which controls the amount of air entering
the engine. When sufficient throttle is given, the vehicle overcomes limiting friction
condition and hence moves forward with passengers and load.
HISTORY OF THROTTLING SYSTEMS
• Early cars such as the Ford Model T had a hand lever to control the throttle.
• Later cars used both foot pedal and hand lever where the hand lever was used to
set the minimum throttle, an early form of cruise-control. Modern cruise control
was invented in 1948 and is usually operated via buttons on the steering wheel.
• Early Chevrolets had the starter pedal to the right of the accelerator. Because it
was difficult to operate this and the throttle pedal, there was a secondary throttle
control knob on the dashboard.
• Many vehicles now include pedals with electric adjustment, a modern iteration of a
manual adjustment system available sporadically since the 1950s.

4. Ford Model T (1908)
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The Model T's transmission was controlled with three foot pedals and a lever that
was mounted to the road side of driver's seat. Throttle was controlled with a lever
on the steering. Left pedal was used to engage the gear. If the driver took his foot off
the left pedal, the car entered high gear, but only when the lever was fully forward.
In any other position the pedal would only move up as far as the central neutral
position. This allowed the car to be held in neutral while the driver cranked the
engine by hand. The car could thus cruise without the driver having to press any of
the pedals.

5. Types of Throttle System
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There are two types of throttling systems used in vehicles.
1. Conventional Throttle System (throttle body controlled by a cable)
Traditionally, the throttle plate has been connected to the accelerator pedal (or gas
pedal) via a cable. If the driver wants to go faster, he presses the pedal, which in
turn pulls the cable and opens the throttle plate to allow more air to enter the engine
2. Electronic Throttle System (throttle body controlled electric motor)
The PCM then analyses inputs from various systems and sensors on the vehicle
(transmission, traction control, engine load, etc.) and sends command to an electric
motor in the throttle body, placing it at the desired position

6. Electronic Throttle Control
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7. Muscle Fatigue While Driving
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Heavy traffic leads to interrupted motion of vehicle. During this process the average
speed of vehicle is around 15 km/h. To attain this speed, the pedal is pressed by
small amount.
This keeps the foot muscles particularly “Extensor Digitorum Longus and Extensor
Digitorum Brevis and Peroneus tertius muscles under strained condition. This leads
to muscle fatigue causing lack of control over the vehicle.

8. Novel Foot Resting Mechanism
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Salient features
1. Foot Resting 2. Variable Stiffness Control
3. Speed Range Magnification 4. Auto-calibration

9. Initial Calibration Procedures
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Initial calibration needs to be done before starting the vehicle and the
following data is measured and recorded.
1. Weight of Foot
This is calculated by pressure sensor when foot is placed on pedal. It is required by
system as this same amount of foot load needs to be balanced during foot resting.
2. Stiffness Calibration
The pedal stiffness has to be set initially through a variable knob on dashboard.
Different users can vary and set the pedal stiffness as per their choice.
These Data can be recorded and saved in the system and every time the user is
changed, he/she can select their driving profiles and this data will be loaded without
performing initial calibration every time (just like how mirror & seat position is adjusted)

10. Sensors’ Performances
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Sensors used to measure various parameters in real-time.
1. Position Sensor (at Pedal)
The displacement reading is sent to PCM which regulates throttle. It is also used to init
iate foot resting action and performs auto-calibration when elongation is produced in
the system elements.
2. Pressure Sensor (at Pedal)
The pressure applied on pedal by the foot is measured & this data is also used to
calculate kfoot (stiffness req. to initiate Foot resting)
3. Rotary Encoder (at rotor shaft)
The angular displacement is measured & is sent to PCM which confirms the
displacement of rotor-shaft after the spiral-spring is calibrated. Also used to
counter-check during auto-calibration.
4. Temperature Sensor
The temperature elevation is measured & calculates and corrects the thermal
expansion in wire and flat spiral spring during auto-calibration.

11. Stiffness calibration for Foot Resting Action
(Theoretical Proof)
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12. System Integration and Working Methodology
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13. Pedal Operations
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• After the initial calibration is done and data is recorded, the pedal can be operated
from the modes given below in table.
• The features of the mechanism like Foot Resting, Variable Stiffness Control and
Speed Range Magnification can be activated/deactivated whenever required.
• Auto-Calibration feature is ON by default to ensure that the system acts efficiently
and produces accurate result and throttle response at all times.
• During acceleration, the FR is disabled and hence VSC and SRM can be activated.
• During deceleration FR is disabled and hence VSC and SRM can be activated.
• If pedal is required to operate normally unlike any conventional pedal, all features
can be disabled.
In case of system failure, sensor readings are taken & system is shut down and
braking is initiated. It is a fail-proof design & will not result in undesired acceleration

14. Servomotor Dynamics
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Pre-calibrated values of rotation with respect to applied load & angular displacement
will be preloaded to the system based on design aspects of Spring, Wire and System
elements. The PCM is programmed for various conditions of operation & servomotor
facilitates various features by adjusting the stiffness value of spring by rotating rotor
shaft,

15. Prototype Details
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Component Material Used
Pedal Aluminium Alloy 7075-T6
Cable AISI 304 Stainless Steel Cable
Drum AISI 420 Stainless Steel
Spiral Spring Inconel 625 Nickel-Chromium Alloy
Specific Materials for various components.
Model fabrication has been done and basic functionality was achieved. Further
development is under progress. Performance testing of prototype will be carried out
on Arduino Due microcontroller board based on Atmel SAM3X8E ARM Cortex-M3
CPU.
• A 32-bit core, that allows operations on 4 bytes wide data within a single CPU
clock
• CPU Clock at 84Mhz.
• 96 KBytes of SRAM.
• 512 KBytes of Flash memory for code.
• A DMA controller, that can relieve the CPU from doing memory intensive tasks.

16. Simulation Analysis
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The modelling of the system components was done on Solid Edge ST7 and during
simulation; the stress-strain and displacement characteristics were recorded for
various parts of the system under maximum loading conditions. The essential
parameters considered during simulation include – average mass of feet (1.38kgs),
force acting (15N), ambient temperature (25 deg C) and elevated temperature
(71 deg C). The results were found to be satisfactory.

17. System Compatibility
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Foot Resting Mechanism (FRM) Cruise Control (CC)
It is effective and provides instantaneous
response. It is faster than cruise control
as foot is not removed from pedal.
Foot is removed from pedal and makes
it difficult to vary speed instantaneously
under emergency situations. Hence
makes it less responsive compared to
Foot Resting Mechanism.
It does not require looking at dashboard
and buttons for its operation. The driver
can keep his eyesight on road.
Requires looking at the steering wheel
and buttons for its operation leading to
diversion of attention from road.
Works at any speed [ 0 – max ]
Works during parking [ 0 – 10 km/h ]
Works during slow moving traffic
[ 15 km/h ]
Works above 60 km/h.
Difficult to maintain constant speed
below 60 km/h.

18. Future Applications
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• This particular mechanism is a subsystem which can be attached to existing
Electronic Throttle Control by performing slight modification in pedal.
• It can be easily incorporated in Gasoline, Diesel and Hydrogen fuelled vehicles.
• It can also be installed in Electric and Solar vehicles with electric motor as their
main propulsion source.
• Wide variety of Vehicles can use this mechanism including busses, trucks & cars.
• It reduces muscle fatigue and gives better control over the vehicle.
• It allows different people to drive a single vehicle by setting their own preference.

19. Conclusion
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• The Muscle Fatigue was eliminated by designing a Novel Foot Resting
Mechanism.
• Modus Operandi and critical aspects of applications were addressed.
• Designed mechanism exhibits multiple features which aids while driving.
• The present system can be integrated with the existing Electronic Throttle
Control.
• Simulation was performed and results were analysed and evaluated for best perf
ormance satisfactory.
• Prototype was made and further development is under progress.
• This mechanism can be integrated to electric and solar powered vehicles.
• System is Fail-Proof and all the features can be turned OFF when not needed.

20. F2016-VDCD-009
THANK YOU