DESIGN AND DEVELOPMENT OF AN INTERACTIVE ROBOTIC HEAD

Introduction

Design and development of robotic head has goal of developing research platform for interactive features in robotics, performing basic head and eye movements like a human head. Although there are large numbers of researches are going on regarding this topic, as far no one was able to develop a completely humanoid robotic head with perfect interactive features.

Project scope

Main objectives of the project are design of a robotic head with basic head motions and vision with movable eyes, development of coordinated head - eye movements and development of the robot head for interactive features.

Modeling of robotic head with close resemblance to a human head, construction of mechanical and electrical designs and software development testing and calibrations are the parts of the project. At the beginning, existing robotic heads and human bionomical data were studied and considering them robotic head is designed with appropriate specifications. A  kinematic  analysis  has  been  carried  out  for  the  robotic head using the Euler angle method to determine the trajectory of  a  pre-specified  point  on  the  head  with  the  variation  of rotational  angles  of  actuating  motors  in  the  neck  section. 

Robotic head is incorporated with 6 DOFs. It has 3 DOFs  for  the  neck  section  and  3  DOFs  for  the  eye movements.  This  has  given  the robotic head  the  capability  to  reproduce natural  human  head/eye  motions  to  a  higher  degree. Binocular  vision  has  been  achieved  using two  cameras  and vision  based  social  interactive  features  are  proposed  to  be implemented on the robotic head. The control and processing system has been divided in to two parts as a station computer for image processing and a  micro  controller  for  the  other control and processing tasks.

features on  anthropomorphic  robotic  heads are tracking  and  following  a  human  hand  which  moves  in  front of  the  head  is  a  more  sophisticated  social  interactive  feature and  this  can  also  be  used  in  developing  further  interactive features  such  as  hand  gesture  recognition  and  responding  to them.  Because  of  that,  initially,  tracking  and  following  a human  hand  with  coordinated  head/eye  movements  has  been selected  as  the  interactive  feature  to  be  incorporated  in  to the robotic head. 

Conclusion

The proper positioning of actuators and vision hardware has  been  discussed  with  due  attention  to  the  related  bio-mechanical  constraints  and  requirements. This is currently in the actual construction phase and once the  construction  is  complete,  it  can  be  used  as  a  research platform for developing socially interactive  features.

Supervised by: Dr.Buddhika Jayasekara

Group members: 
M.H.C.Lakshan | L.H.H.Madurangi | M.K.B.S.Munasinghe |M.A.V.J.Muthugala 

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Dynamic Traffic Light Controller

Introduction

This project is to design a dynamic traffic light controller, which adopts according to real time traffic flow and then control the switching of signals according to the traffic condition. In this design, induction loops are used as vehicle detectors and the control of traffic lights is done dynamically by a fuzzy logic controller in such a way to get a smooth flow of traffic. The control signals from main controller to the controllers at each traffic light is done through wireless communication which is another significant feature in this design.

Project Scope

There are three main sub sections in the project as in names, detection, controlling and communication. Under the first section vehicles has to be detected to get a proper idea of real time traffic situation. Therefore one objective of this project is to build a system to detect vehicles in order to get information about traffic flow to implement next sections. As a vehicle detection system, induction loops have been used which is one of the most commonly used methods for vehicle detection with higher accuracy and higher durability compared to other commonly used methods.

The real time vehicle count is an important fact in analyzing the current traffic condition at a particular junction and as in this case a four-lane junction is basically considered, there are eight induction loops that are been placed as two per each lane as shown in the figure. Two of the loops of one lane are placed at a pre-determined distance based on data collected about the traffic condition of particular lanes. However fundamentally one induction loop sensor is been placed near to the intersection while other one is been placed at a pre-determined distance from this. That distance is determined according to the maximum possible traffic condition of each lane so that at all times, traffic queue is in between the two loops. The difference between the information through two induction loop sensors at one lane is been used to calculate the traffic density at a particular lane. 

Next section in the project is to build up a proper controlling methodology. For that analyzing the traffic condition at real time may pose the optimum solution for traffic congestion problem. In that case fuzzy logic is used in this project as it gives a mathematical version for representing human knowledge and experience involving indistinct concepts and also it is an effective mechanism to systematically formulate a solution to complex uncertain problems.In main controller there are separate fuzzy units for each lane and the waiting time of vehicles and traffic density at respective lane has considered as two main inputs to the unit in this project. As stated earlier queue length or traffic density is determined by the induction loop data while the waiting time is the incremental time which started from 0 at the moment red light is ON of respective lane. Then from the each fuzzy unit variable number gives as an output, after considering the inputs. And send those four variable values from each lane to the fuzzy comparator which is also in the main comparator from which gives out the most suitable next phase to be opened and also whether current green phase should terminate or continue. Using those two outputs final phase selector decide the phase which should have green light ON. Communication between detectors and the central controller will be done using wireless technology.

Conclusion

In Sri Lanka most popular method which has been used to control the traffic congestion problem in many urban cities are conventional traffic light controllers. These are incorporate with pre-determined program which is based on chronological data at particular junctions. Since traffic congestion are random and non-linear matter, those pre-programmed method have not been able to achieve the most effective signal timings which in order to get a smooth flow of vehicles at the multilane junctions. But in application this method will solve the problem in most optimum way.

Project Supervisor: Dr.Satish Namasivayam

Group members: I.L.Kumarasinghe | K.J.Lakmewan | G.P.S.Lakshan | K.A.T.Lasagani

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Design and Build a Real Life Power System Model

Introduction

It is important for an Electrical Engineering undergraduate to know about power systems in theoretical as well as in a practical approach. Thus, a power system simulator is ideal to understand practically the theories learnt in class. Commercially available models though are in existent, the endeavor was taken to design and build a power system simulator, as a final year project. The simulator is a scaled down model of the actual power system prevailing in the Sri Lankan context. Though it is a scaled down model, all electrical components such as generators, relays, circuit breaker panels are all actual industry used components. As a continuing project many aspects are being developed piece by piece under the guidance of the supervisors and with financial support from the industry. This project provides the basis for the fulfillment of the aspiration by the Department of Electrical Engineering, University of Moratuwa, to give a firsthand experience for the undergraduates before they encounter industrial training.

Project Scope

Figure 1: Power System Model

When completed the model will consist of,

•     A synchronous generator/transformer unit with voltage control   
•     A prime mover (an induction motor) with governor control (VSD drive)
•     Manual synchronizing facility with the grid (mains supply)
•     4 Transmission lines, a grid substation and a distribution system
•     Variable resistive and inductive loads
•     An integrated protection system to detect and clear the faults
•     Instrument transformers (Current Transformers and PotentialTransformers) to provide information    to the protective and metering systems
•     Metering facilities at various points in the system
•     Vacuum Circuit breaker Panels and Facilities for remote operation of circuit breakers.
•     A fault creation facility for the application of faults on transmission lines
•     Laboratory practical’s on power systems, fault clearance and protection schemes

Project Objectives for 2013 

This year embarks the 4^th phase and the following objectives are initiated for the completion of the project.

Fault & Load flow study and current transformer specification

A thorough load flow analysis was done to understand the system in operation. A fault study was done to determine the fault currents in different instances. The nominal current and fault current was taken from the study. The relay burdens were found by the manuals and other official documents. The knee point voltage was then calculated. By the parameters it was concluded that current transformers with a ratio of 60/5 and burden of 7.5VA would be best for implementation as they were commercially available.

Implementation of donated mechanical and numerical relays

Several numerical and mechanical relays have been donated by numerous contributors and these are being appropriately implemented onto the circuit breaker panels in the power systems laboratory. Due to the diverse nature of the relays, they were studied individually and extensively, ultimately learning how to program and operate. The relays which were donated will simulate the following protection schemes.

1. Transformer protection (Over current, Differential)   
2. Line Protection (Differential, Distance, Overcurrent, Directional overcurrent)
3. Generator protection ( Overvoltage, Negative sequence, Overcurrent, Differential)

Implementation of load

It was decided that for the start, a resistive load of 3.3kW would be implemented to complete the distribution segment of the power system model. Implementation of inductive loads will be facilitated in the expansion of the project in the future.

Laboratory practical’s

Currently laboratory practical’s are being designed to be tested among the undergraduates as a pilot project before establishing it in the curriculum.

Generous donations have been made by LTL Holdings (Pvt) Ltd, Ceylon Electricity Board, Balfour Beatty engineering services Ceylon (Private) Limited,Hayleys Industrial Solutions (Pvt) Ltd, ABB Sri Lanka, FDK Lanka (Pvt) Ltd and by Lanka Electricity Company (Pvt) Ltd.

Project Supervisors: Professor J.R.Lucas | Eng. J. Karunanayaka
2009/2010 Group members: G.B.Alahendra| A.C.P.Aluthgama| P.G.L.Arachchi | G.U. De Silva
2010/2011 Group members: S. V. Herath| K. S. Hettiarachchi| W. J. M. L. Himal |C. Ileperuma
2011/2012 Group members: T.G.R.Lalitha | K.D.S.Kuruppu | L.L.U.J.Lenaduwa|   D.R.Liyanage
2012/2013 Group members: A.R Devinda| D.M.S Dissanayaka| C.L Fernando | M.H.M Fernando


For further information please feel free to contact us by energyzee.projects@gmail.com

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Development of a prototype of vehicle active suspension system

Introduction

The aim of the project is to develop an active suspension system for vehicles. In this project, the main objective is to suppress the vibrations caused due to the imperfections of the road surface and give a better stability to the sprung mass. In order to achieve this goal, the suspension system changes its characteristics and suppress the vibrations according to the vibration level of the road and applied disturbances.

Project scope

The proposed method consist of a controller, linear motor driver, linear motor acting as an actuator and feedback sensors are used to complete the control system. The controller will accumulate suppressed vibration performance details of the system and takes position feedback of the motor using a linear encoder and motor current feedback using a current sensor to provide desired output signals to the motor driver. The desired output is calculated using motor disturbance observer technique. The response of the suppressed vibration is transferred to controller using a 3D accelerometer and the controller save them for analysis.

Figure 1: Block Diagram

The control signal then transferred into the motor drive module which provides power to linear motor USING PULSE WIDTH MODULATION. The actual current if the linear motor is measured by a current sensor using shunt resistance current measurement method. Current sensor used in between driver and linear motor to calculate the exact current transferred to motor. This measured value then used in DOB to calculate load torque.  The Linear motor acts as the actuator of system, providing required dynamic suspension response to suppress vibration experienced by motor body itself. The linear motor is capable of delivering required torque and speed response directed by controller through motor driver.The Linear encoder measures the motor position and sends the position measurement to controller for system response measurement. These systems are connect as described above and as in above block diagram to provide a viable solution to our problems.

Conclusion

The effectiveness of the active suspension system with respect to prevailing passive suspension system can be observed by comparing the vibration suppression capability of the both systems in different vibration levels. The effective usage of the active suspension system can be implemented to improve the control, contact and comfort of the motor vehicles.

Project Supervisor: Dr.Harsha Abeykoon
Group members: P.A.M.M.B. Abeyrathna | W.A.S.P. Abeysiriwardane | S.W. Amarasinghe | W.M.S.L. Ariyasinghe

For further information please feel free to contact us by energyzee.projects@gmail.com

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