Manivannan P. V.

In this work an Engine Management System (EMS) using a low cost 8-bit microcontroller specifically for the cost sensitive small two-wheeler application was designed and developed. Only the Throttle Position Sensor (TPS) and the cam position sensor (also used for speed measurement) were used. A small capacity 125CC four stroke two-wheeler was converted into a Port Fuel Injected (PFI) engine and was coupled to a fully instrumented Eddy Current Dynamometer. Air-fuel ratio was controlled using the open loop, lookup-table [speed (N) and throttle (α)] based technique. Spark Time was controlled using a proportional / fuzzy logic based close loop control algorithm for the idle speed control to reduce fuel consumption and emissions. Test results show a significant improvement in engine performance over the original carbureted engine, in terms of fuel consumption, emissions and idle speed fluctuations. The Proportional controller resulted in significantly lower speed fluctuations and HC / CO emissions than the fuzzy logic controller. Though the fuzzy logic controller resulted in low cycle by cycle variations than the original carbureted engine, it leads to significantly higher HC levels. The performance fuzzy logic can be improved by modifying the membership function shapes with more engine test data. Copyright © 2007 by ASME.

A two-degree freedom air fuel ratio controller (Model based feed forward transient plus closed loop Proportional Integral-Derivative (PID) steady state controllers) developed for controlling the air fuel ratio of the charge in a small displacement (125 CC) SI engine is presented. The feed forward controller's airflow and injector models were developed after conducting extensive experiments on the engine modified for the Port Fuel Injection (PFI) operation. A dynamic air fuel ratio model obtained (air fuel ratio changes measured using an UEGO sensor) by injecting the Pseudo Random Binary Signal (PRBS) signal in addition to base line fuel injection pulse, was used for designing the PID controller. Optimal PID gain values were identified using Nelfer-Mead optimization technique. The control algorithms were implemented and optimized using SIMULINK blocks that are run under dSPACE on the MicroAuto box hardware. The optimized control algorithms were ported on the specially designed, in-house built, low cost engine management system (EMS) developed around an 8-bit microcontroller. The spark timing was also controlled simultaneously for knock free operation. The two-degree freedom air fuel ratio controller could maintain the air fuel ratio under steady and transient conditions closely. High thermal efficiency and low HC & NOx emissions were achieved using the developed EMS. At higher speed elevated NOx emission was observed, due to the use of leaner mixture. The improvements are expected to be higher if a suitable smaller injector is used. Copyright © 2012 by ASME.

Using SONAR as the primary range finding sensor has largely been abandoned due to problems such as limited range, large bearing errors and large beam widths. However, SONAR is used conjunction with other sensors such as LIDARs, RADARs and vision sensors for ranging and obstacle avoidance in many autonomous vehicle applications. In this paper, we propose a solution to reduce the range and bearing error significantly, and thus improve the performance of the SONAR. Using the results from the Gaussian Correlation Inequality, we derive probabilistic transformations that can improve the range and bearing measurement of the SONAR, thus reducing the sensor error. We are also presenting simulation study, to place bounds on the types and characteristics of the SONARs within which our model's performance is optimal.

In this work an Engine Management System (EMS) using a low cost 8-bit microcontroller specifically for the cost sensitive small two-wheeler application was designed and developed. Only the Throttle Position Sensor (TPS) and the cam position sensor (also used for speed measurement) were used. A small capacity 125CC four stroke two-wheeler was converted into a Port Fuel Injected (PFI) engine and was coupled to a fully instrumented Eddy Current Dynamometer. Air-fuel ratio was controlled using the open loop, lookup-table [speed (N) and throttle (α)] based technique. Spark Time was controlled using a proportional / fuzzy logic based close loop control algorithm for the idle speed control to reduce fuel consumption and emissions. Test results show a significant improvement in engine performance over the original carbureted engine, in terms of fuel consumption, emissions and idle speed fluctuations. The Proportional controller resulted in significantly lower speed fluctuations and HC / CO emissions than the fuzzy logic controller. Though the fuzzy logic controller resulted in low cycle by cycle variations than the original carbureted engine, it leads to significantly higher HC levels. The performance fuzzy logic can be improved by modifying the membership function shapes with more engine test data.

A cognitive decision making algorithm, which tries to emulate human driver behaviour, for autonomous vehicles is presented in this paper. The decision making process, as well as the integration of the decision making with real time control in different traffic scenarios is studied through simulations using vehicle dynamics model for a car like vehicle. The decision making algorithm was found to perform better, when integrated with the ANFIS Fuzzy Logic longitudinal Control than with conventional PID control. The simulation results with the different traffic scenarios demonstrate the successful integration of the real time control and decision making modules of the Intelligent Vehicle Architecture.

Unmanned Aerial Vehicles (UAVs) require advanced path planning and obstacle avoidance algorithms for navigation. In this paper, the Flood Fill Method (FFM) was employed for navigating an autonomous quadcopter in a simulated environment created using MATLAB. The proposed method was compared with the traditionally used Potential Field Method (PFM). For a known terrain, Flood Fill Method works computationally faster for a repetitively same path. These methods were compared in terms of the parameters such as avoiding random obstacles for variable starting and destination positions, the time required to complete the journey, and the optimum path selection.

The aim of the present work is to study the effect of process induced defects on the transport mechanism in ITO/InP solar cells. A detailed analyses of electrical properties along with XPS studies have been carried out on ITO/p-InP cells prepared by reactive electron beam evaporation and spray pyrolysis techniques. It is observed that thermionic field emission (TFE) in ITO/p-InP junctions prepared by e beam and tunnelling (below 300 K) and recombination at depletion region (above 300 K) in sprayed junctions are the dominant transport mechanisms. The cells prepared by both the techniques conform to Semiconductor-Insulator-Semiconductor model and the interfacial layer comprises of In2O3 and InPO4 as revealed by XPS data.

This paper investigates a sensor-minimal approach to motion control in variable stiffness actuators. This control approach aims at reducing the need of sensors for tracking a desired trajectory. By this, problems caused by collocation and additional noise in measurement signals could get reduced along with economic benefits due to lower system complexity. Control laws are designed using a passivity-based approach which requires only one sensor, i.e, for measuring actuator position. Due to the demand of information about actuator velocities in the control law, those are calculated using a velocity compensator, numerical calculation, and linear filtering. The parameters of the controller and the velocity compensator are selected based on the global asymptotic stability requirements. To compare the three methods, those are compared regarding the example of the variable torsion stiffness actuator (VTS). Using the controller with the velocity compensator shows good results in simulations and experiments. Numerical calculation achieves slightly worse results while linear filtering does not show feasible results.

Minimally Invasive Surgery(MIS) is a type of surgery where surgical instrument e.g. laparoscope, endoscope etc. is inserted into a human body through a small incision. The instrument has to be manipulated about the insertion point also known as trocar point to avoid tearing of the skin. Robotic manipulators with Remote Center of Motion (RCM) mechanism are extensively used in this kind of surgery. Kinematic design is important phase in design of such manipulator to ensure safety, accuracy, ergonomics and dexterity. In this paper link lengths of the software controlled RCM manipulator are optimized to maximize global isotropy. Global Conditioning Index (GCI) over the defined workspace is used as metric of global isotropy.

This paper introduces IITM B-Robot, a bioinspired reconfigurable quadruped robot, capable of transforming its posture from erect to sprawl and vice versa, and capable of changing its configurations depending on the terrain. The capability ensures the robot able to move with maximum speed and greater stability at all-terrain conditions. In this research work, it has been proposed to develop a robot having 3-DoF legs for reducing energy consumption and cost reduction. Two identical robot designs are proposed, one with 3-DoF legs and another having 4-DoF legs and a comparative study has been done between them by calculating the torque requirement at each leg joints by carrying out multibody dynamics simulation for a complete robot. The trajectory planning equations have arrived such that the robot legs touchdown with minimum impact. Optimal design for impact to save the actuator from damage and finite element analysis of parts for refinement of dimensions has been carried out.