DARSHAN NAYAK BS, MS Mechanical Engineering

University of Florida

SMART WALKING STICK Overview: Built a working prototype of a low-cost, dependable smart walking stick that enables visually handicapped to

navigate better. The model features an add-on based device to existing walking sticks / canes.

Sensors: 40 kHz ultra-sonic transmitter receiver module

700nm Infrared sensor module

8051 microcontroller

LDR

Description: With lot of advanced technologies available in the market for

visually handicapped, we aimed at creating a cost effective

solution with an add-on feature. The smart walking stick is a

device that consists of a pre-modeled sensor setup that can be

fixed onto an existing walking stick / cane used by visually

handicapped.

On analysis of navigational parameters, we came up with 3

sensors that would help walk-through most environmental

conditions. The 3 sensors are marginal sensor, step and

obstacle sensor.

The obstacle sensor helps detect wide range of course

obstacles that a human would face onto when navigating in any

environment. Since it would include far reached objects over a

range of 0 to 15 feet, an ultrasonic sensor was installed. Since

these are powerful sensors with a coupling of transmitter and

receiver, we narrowed down to an effective angular range of

120 degrees. For a feedback mechanism, a 10 kHz buzzer was installed that would respond if any obstacle were

approached.

Infra-red sensors were used for step and marginal sensors. The primary objective of these sensors were to detect

any low height obstacles and depressions along a path. These consist of an emitting transmitter-receiver module

connected to an 8051 microcontroller that is programmed as a NOT gate.

Based on this principle a working prototype was built and tested in a controlled environment and some of the

results are shown below in a graphical representation. It was noticed that the add-on sensor module was effective

in navigating more efficiently than an ordinary cane. Although, we faced some drawbacks such as low power back-

up from the batteries, bulky final model and inefficiency in bright light conditions. The design can be further

worked upon to make it a marketable product.

Fig 1: Path traversed without

Smart Stick

Fig 2: Path traversed using the

Smart Stick

Smart Walking Stick Prototype

DESIGN OF EXTERIOR TRIM OF A CAR

Overview: A full scale computational model of a BMW® Z4 Coupe 2007 was created using surface design on PTC Creo 3.0.

For my project in a course for computational methods for design and manufacturing, I created a 3D model for the

exterior trim / surface of a car. The main objective of the project was to learn and utilize surface modeling on an

industrially used CAD modeling software.

I approached using a blueprint of the model

and scaling it to the real dimensions

creating a box environment. Smooth

surfaces were created in parts surrounded

by boundary curves / splines ensuring there

is C-1 and C-2 continuity in the curves. These

curves include B-splines and cardinal splines

that are composed of Hermite polynomials

thus enabling tangential and curvature

continuity.

To improve the productivity, I created half

the model and mirroring it in the final stage

of the exterior trim. Since designing, a car with all the parts is a lengthy process, I added some key features such

as tire and differential assembly with a few interiors for the aesthetic appeal of the model.

Solidworks was used as a rendering software as the features are more appealing than other software available.

This gives the final model a more visual appeal and can be used for product advertisement.

A few more models of the car are displayed below.

MUD FILTRATION TRAILER

Overview: A concept model was created for a portable Mud filtration unit on a trailer based system.

I took the initiative for this project during my internship program with National Oilwell Varco (NOV), a leading oil

and gas equipment manufacturer. The company has thousands of products for different processes in oil and gas

extraction technology. Mud is a fluid that is an important component in the drilling process. It has many

advantages when the boring machines drill through the earth’s crust. The act as a heat dissipation medium,

lubrication, soil removal medium and a pressure barrier. These fluids have properties that are not available from

natural sources and since they are synthetically made, discarding used mud fluid is not viable and therefore they

are undergone a filtration that consists of a series of equipment to perform the process.

NOV did not have a product that was easily portable from one rig to another. I therefore created a concept

model with the whole unit fitted onto a trailer based system that can be moved using the help of a truck. The

design was created based on the road and safety standards. Image below displays the model generated on

Solidworks.

RACING BICYCLE

Overview: Reverse engineering was performed on a bicycle to create a conceptual model of a racing bicycle.

This was a project undertaken as a part of CATIA V5 certification course from CADD Center Bangalore (India). A

conceptual model of a racing bicycle was created on the idea based off a real scale bicycle using extensive use of

part and assembly modeling. The created model was further rendered on CATIA render toolset. A few pictures

of the generated model are shared below.

The model was created using 20 parts that were assembled using constraints that follows the laws of motion

and degrees of freedom of each part.

5 LINK DRIVE TRAIN DESIGN

Overview: Solid modeling and 3D printing of a motion convertor mechanism.

This project was undertaken for a 3D design and 3D printing competition at the University of Florida in the

Department of Mechanical and Aerospace mechanism. The objective of the project was to create a model that

could be fabricated using additive manufacturing procedures in a 3D printer that were to have a practical

application.

I came up with a simple mechanism that could convert a rotory motion to a 180 degree oscillatory motion. The 5

link drive mechanism consists of 5 links of specific dimensional parameters that could effectively function to a

positive output. A few images below represent the 3D rendered model created on Solidworks 2014. The part

models were converted to .STL files as a mode of input to the 3D printing machine.

I am very passionate about product design and performing engineering analysis on the model to deem it a

workable model. I find myself to be a part of the whole product lifecycle management (PLM) cycle.

This motivated me to complete certifications in mechanical and design analysis software and to get a technical

depth of design and manufacturing, I graduated with a Master’s degree in mechanical engineering. I am

currently seeking challenging opportunities as a product design engineer in the corporate world and would love

to be a part of your engineering team where I believe I can make a difference and be an integral part of the

team.

I thank you so much to have a look into my portfolio. I eagerly look forward for a chance to be interviewed to

discuss more about me as well as opportunities at your firm.

Regards,

Darshan Nayak

THANK YOU