Automatic Gear Shifting Mechanism in Two Wheelers

Abstract

Abstract: Motorcycles are widely used around the world particularly in INDIA. The gear shifting system of the motor-cycle is conventionally manual. This report covers development of an indigenous gear shifting /changing system for the standard motorcycle. By this system the manual mechanical gear- shifting will remain unchanged because an additional electro-mechanical system is placed on the top of the lever to shift the gear and automatically control the clutch. So the system has both the option manual as well as automatic. The system uses low cost microcontrollers to make the accurate decision for shifting the gear up and down by observing the speed, and it controls the clutch transmission where necessary. The complete hardware and software has been tested and the functioning of the automatic gear shifting system is verified. System is flexible and can be used with any motorcycle ranging from 50 to 200 cc. General Terms Automation. Keywords Linear Actuator, Arduino, Hall effect sensor, Atmega328, Servo motor, Gear shift lever

Introduction

I. INTRODUCTION

There  are  already  some  inventions  done  of  gear  box  for motorcycle for transmitting the torque from engine crankshaft to the rear  wheel of the motorcycle. The gear box is used to vary the  torque as per  the different driving  conditions. The gearbox increases the required torque  for start the ride and put the motorcycle in to motion. After the start or the running of the motorcycle there is no need of high torque, so now gear box will transmit the optimum torque to the rear wheel at high speed. For the operation of gearbox and shifting the gear there is need of some effort of driver of motorcycle. A foot lever is used to shift the gears in a motorcycle. Also, a clutch is placed between the engine and the  transmission  in order to  engage and  disengage  the  flywheel  with  the  transmission.  So  for smooth driving of motorcycle there is need to time these two operations  perfectly. This  gear shifting  becomes a  tiresome process for most new drivers. This can also help in reducing accidents. Therefore  we  propose  the  development  of  an  automated system  which  can  change  the  gears  automatically  with  the help of speed. This automated system which we propose will also be  beneficial  in terms of fuel  economy and  production costs.  In our developed system  , both  the gear and the clutch are controlled electro- mechanically by a micro  controlled based computer  system.  This  system  does  not  require  any modification  to  the  engine.  The  equipment  is  mounted externally on the body  of the motorcycle. This system  shifts the  gear up  and down  electro-mechanically  like the  human rider by sensing the speed of the vehicle, but the system shifts the  gear  at  exactly  the  correct  speed,  which  produces  the smooth  gear changing  sequence. The  engine runs  smoothly without any knocking , which increases the  engine life. This proposal  is  different  from  the  one  used  in  cars  as  it  uses electromechanical actuators.

II. GENERAL TERMINOLOGIES 

1. Sensors and Actuators A device which detects  or measures  a physical property and records, indicates, or otherwise responds to it. An actuator is a component  of a  machine  that  is  responsible for  moving  or controlling a mechanism or system.
2. Servo Motor and Linear Punching Actuator  A servo  motor is  a  rotary  actuator  or  linear  actuator  that allows  for  precise  control  of  angular  or  linear  position, velocity  and  acceleration.  It  includes  a  DC motor with    a sensor for position feedback. A linear punching actuator uses it’s to and  fro motion for  precise control of  angular or  linear position, velocity and acceleration.
3. Manual Transmission in Bikes  There  are three basic  controls to  operate  when  it comes  to shifting a motorcycle:

a. The throttle

b. The clutch, and 

c. The gear selector.  The throttle controls the engine speed, the function of clutch is  to  engage  and  disengage  the  transmission,  and  the  gear  selector  selects the gear.

Pull the  clutch towards  you using your  left hand,  and   revolution of   the  engine  with  certain r.p.m  will  be  there  without  moving  the  bike  forward. Releasing of  the clutch while the transmission is "in gear" (ie, not in neutral), and you'll move the bike forward.

4. Automatic Transmission of Bikes An electronic  gear-shifting  system is  a  method  of  changing gears  on  a bike,  which  enables  riders  to  shift  with electronic switches  instead  of  using  conventional control levers and  mechanical  cables.  The  switches  have  been connected  by  wires  or wirelessly to a battery  pack  and to  a small electric  motor that  drives  the derailleur,  switching the chain from cog to  cog. Use  of an electronic system is  to change  gears  faster,  and  because  the  system  does  not use Bowden cables and can calibrate itself, it may require less maintenance.

III. LITERATURE REVIEW

1. Automated Transmission System: [1] Automated Transmission is a clutch-less (without clutch pedal) manual transmission  system  which  uses electronic sensors,  processors  and  actuators  (hydraulic  or electro mechanical) to do clutch actuation and gear shifts  as  per  command  of  the  driver.  Automated Transmission  system  uses  a  conventional  manual transmission, actuators and control unit to automate the  whole  process.  The  system  consists  of  three sections of sensors, processors and Actuators.
2. Gear Selecting Mechanism:  Conventional way of gear  selection  was  been  using  a  gear  speeder  to detect  nicks on  transmission gear teeth.  However, measurement  over balls, runout  and tooth-to-tooth composite error could not be measured by the gear speeder and skilled workers were always needed to operate the gear speeder. Efficiency of these highly mechanized  processes  appreciably  depends on  the reliability  of  work  of  tooth  gearings  of  machine drives.
3. Impulsive  responses  in  geared  systems  with multiple  clearances  are  studied  when  the  mean torque excitation and system load change abruptly, with  application  to  a  vehicle  driveline  with  an automatic transmission.

A. Reason for Topic Selection

1. Changing gears manually is a gruesome task which has also been very disturbing for the riders.
2. However, switching to automatic transmission can help us overcome all such situations.
3. Abrupt stopping of the engine in traffic due to poor handling of clutches can be avoided.

B. Aims and Objectives of Research

1. To design the system for automatic transmission.
2. To  calculate  the  dimensions  of  the  magnet  to  be used and gear ratios being used
3. To code the required adruino program for the servo motor and the linear punching actuator.
4. Analysis of designed mechanism.
5. Fabrication and testing of designed mechanism. Recommended font sizes are shown in Table 1.

IV. METHODOLOGY

1. Literature review

The study of following research papers are done:

a. Modeling of an automated manual transmission system.

b. Development of a New Automatic Gear Selecting Machine for Automobile.

c. Tooth wear modeling and prognostication parameters of engagement of spur gear power transmissions.

d. Impulsive response of an automatic transmission system with multiple clearances: Formulation, simulation and experiment.

2. Calculations Speed range of gearing and vehicle Now here we calculate the range of speed of gear box output power and range of all minimum and maximum rpm of the gear box shaft in every gear mashing condition… If we consider the speed for first gear is 0km /h to 20km/h for second 20km/h to 30km/h for third 30km/h to 45km/h and for greater than 45km/h take for the gear mashing. Here, we have the range in term of speed in km/h now converting the vehicle speed in rpm for that use the equation , as given below. N=V*60/3.14 D;  Where , N=speed in rpm  V=speed in m/s  D=tire diameter in m  Take, D=0.80 meter tire diameter.  Thus by using this equation we can find the our speedometer speed km/h can convert in revolution per minute(rpm).  We have output gear reduction as 9.889 (calculated by using the output shaft dia. And the teeth on rear to front sprockets) The gear torque is shown as below. Gear arrangement Speed of vehicle in km/hr.  Speed of vehicle in rpm. Speed on output shaft of gear box in rpm.

 Lower Higher Lower Higher Lower Higher 1st 0 12 0 117.95 0 1166.41 2nd 12 24 117.95 235.90 1166.41 2332.82 3rd 24 36 235.90 353.86 2332.82 3499.32 4th 36 50 353.86 491.47 3499.32 4860.13  We have gathered data from 2 different drivers.

V. CODING

The  coding  for the  servo motor  using  the adruino  software was completed. This program allows theadruino to control the servo  motor  functioning  according  to  the  situation  of  the drive. The code that is written works  on the  Boolean principles. It gives a positive signal (1) whenever the gear has to be shifted. In any other case, it is (0). If, else statements are used for shifting the gears whereas time delay is used to manage the operation of clutch. The code to display in the current gear is also written. 5.1 Design In this project working and model some extra devices are used which are not generally  used in the  motorcycle and  for gear shifting.

1. Magnetic clutch:
2. Relays
3. High torque motor(wiper motor)

 VI. MANUFACTURING

The prototype is manufactured on the Honda CBZ bike. 6.1 Construction Flow chart:  Fist  of all,magnets will  be placed on  a rear  wheel  and and r.p.m  sensor  will be  placed.  As  the  wheel  rotates  magnets attatch to the wheel also rotates. The hall effect sensor which works on the principle of hall effect will generate  the voltage.  When magnetic field  will pass pependicular to the field, this voltage  will  be sent  to the  ECU  and according  to situation ECU  will  give  commands  to  actuator;  thus  changing  gear back and forth. 6.2 CAD Model  

Conclusion

This system is flexible and can be implemented on a motorcycle available in the Indian market without any modification. The motorcycle manufacturing can also use the system in their vehicles because it can be easily fitted to the motorcycle and there is no need of internal modification of the gear system. By installing this low cost system in their motorcycle. Companies may also be able to increase their sale due to availability of these new features. This will also help in improving fuel economy in addition to improving the parts lifetime.

References

[1] Gianluca Lucente, Marcello Montanari, Carlo Rossi (2006) ‘Modelling of an automated manual transmission system’ University of Bologna, Viale Pepoli 3/2, 40123 Bologna, Italy. [2] Y. Kawasaki, M. Shinoda, S. Nojiri (2005) ‘Development of a New Automatic Gear Selecting Machine for Automobile Transaxle Manufacturing’ lsuzu Motors Ltd./Japan. [3] Valentin Onishchenko (2008) ‘Tooth wear modeling and prognostication parameters of engagement of spur gear power transmissions’Donetsk National Technical University, 58 Artjom Street, 83000 Donetsk, Ukraine. [4] Ashley R. Crowthera, Rajendra Singha, Nong Zhangb, Chris Chapman (2007) ‘Impulsive response of an automatic transmission system with multiple clearances: Formulation, simulation and experiment’ Mechanical Engineering Department, The Ohio State University, 201 West 19th Ave, Columbus, OH 43210, USA.

Copyright

Copyright © 2022 Shubham Sutar, Dhiraj Palkar, Rushikesh Karche, Vanamala Kadam. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.