Mr. Josh Udar Freeman has been teaching and conducting research at Amrita University's Amritapuri Campus for nearly 8years. He is originally from the United States and formerly held Field and Test Engineering positions within General Motors, specifically working on their Heavy Duty Diesel-Electric Hybrid Drive Systemsand Automatic Transmission Controls programs. His Masters Degrees is in Electrical Engineering from the University of Oklahoma and his Bachelors Degree is in Mathematics, also from the University of Oklahoma. He is currently working towards a PhD at Amrita University in the field of Solar Thermal Energy Systems.

At Amrita, Mr. Freeman is a member of the Amrita Center for Wireless Sensor Networks and Applications, where he has been a core team member of their Wireless Sensor Network Based Landslide Detection System. Hehas also taught Renewable Energy subjects such as Solar and Wind Energy and founded the Robotics Lab. He has a long engineering background in the design, fabrication testing, and validation of various electro-mechanical systems, including electric vehicles and solar powered race cars. Recently, he has been helping to create Virtual Labs for MHRD in Solar Energy, Wind Energy, Energy Storage and Mechanics of Solids. 


Publication Type: Conference Paper
Year of Conference Publication Type Title
2015 Conference Paper J. Freeman, Keerthi, K. Sb, and R.Chandran Lekshmi, “Closed loop control system for a heliostat field”, in Proceedings of IEEE International Conference on Technological Advancements in Power and Energy, TAP Energy 2015, 2015, pp. 272-277.[Abstract]

The alarming energy crisis, heightened by the continuing depletion of fossil fuels, accentuates the need for the development of renewable energy technology, knowledge, and infrastructure. A Central Receiver (Power Tower) Solar Energy system uses heliostats (motorized planar reflectors) to continuously reflect direct radiation from the sun onto a central receiver. This paper discusses a novel closed loop control system for a heliostat field. In this system, rough adjustment of the heliostat is performed using an Inertial Measurement Unit (IMU). Precision adjustment of the heliostat is performed by inducing a small mechanical vibration in the heliostat's reflective surface, using a piezoelectric actuator. This vibration creates time-dependent changes in the light waves reflected from the heliostat, which can be detected by photo-sensors surrounding the thermal receiver target. The position of misaligned heliostats can be corrected once they are identified by FFT analysis of the light waves received by the photo-sensors. This technique can, in principle, control thousands of heliostats simultaneously. The control system is coded using MATLAB. © 2015 IEEE.

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2014 Conference Paper J. Freeman, U., K. E., and S.R., R., “Study of the Errors Influencing Heliostats for Calibration and Control System Design”, in IEEE International Conference on Recent Advances & Innovations in Engineering , Jaipur, Rajasthan, India, 2014.
2013 Conference Paper J. Freeman, Varghese, J. Thomas, and Rekha, P., “WSN based heliostat control for a solar thermal cooking system”, in Energytech, 2013 IEEE, Cleveland, OH, 2013.[Abstract]

This paper proposes a wireless sensor network based heliostats control method for an industrial scale solar cooking system. Even though different designs are available they have suffered from different problems especially regarding effective tracking, high cost and convenience and other constraints such as scalability and simplicity. This paper, therefore, describes an efficient design that overcomes the earlier problems by using a highly precise astronomical calculation based approach along with wireless communication for efficient tracking of the sun which in turn reduces the overall system cost and simplicity. The proposed system uses a one tier wireless sensor network (WSN). The main feature of this work is the implementation of the highly accurate NREL algorithm, with precision timing provided by a GPS receiver within a low-cost wireless sensor network framework.

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2013 Conference Paper J. Freeman, Shankar, B., Elango, M., and Achuthan, K., “Virtual labs battery and ultracapacitor characterization”, in Global Humanitarian Technology Conference: South Asia Satellite (GHTC-SAS), 2013 IEEE, Trivandrum, 2013, pp. 228-233.[Abstract]

Virtual labs help students and professionals to learn subjects practically. Remote triggered virtual labs, in which real hardware is remotely controlled is especially well suited for students who do not have access to high quality, modern, and often expensive lab equipment. It also allows to students to conduct laboratory experiments on their own time and repeat them as often and when necessary. In this paper, we have implemented Energy Storage studies in (batteries and ultra(super)capacitors at the collegiate level through remote triggered virtual labs. The hardware and software system allows the user to study the charge and discharge characteristics of different types of batteries and ultracapacitors. This will create interest for students and professionals to study more on batteries and ultracapacitors and emerge with new ideas on energy storage. In this work, we compare two hardware setups, one made from scratch with low-cost components and the other created using professional, research grade components. The paper focuses on the design, implementation, control system, measurement, communication protocols and integration with the internet for these two testing setups using Labview.

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2013 Conference Paper J. Freeman, Varghese, J. Thomas, and P., D., “WSN based tracking for a concentrating solar thermal energy system”, in 1st IEEE Conference on Technologies for Sustainability (SusTech), 2013 , Portland, OR, 2013, pp. 203-207.[Abstract]

This work describes a Wireless Sensor Network (WSN) based control system for a concentrating solar thermal energy system. Concentrating solar thermal systems require precise tracking of the sun in order to operate most efficiently. Parabolic trough systems require at least one axis of tracking, while the heliostats used in "power tower" systems require two-axis tracking. The system described here uses a wireless sensor network, a single GPS receiver, and the ultra high accuracy solar position algorithm developed by the National Renewable Energy Laboratory (NREL) to control the tracking of the reflecting surfaces of a solar thermal system. A number of energy efficient methods are used within the WSN to optimize the system's performance. Preliminary results are given showing correct networking and tracking system operation.

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2013 Conference Paper J. Freeman, Sabu, M., Shankar, B., and Achuthan, K., “Novel wireless performance monitoring for small wind turbines”, in Technologies for Sustainability (SusTech), 2013 1st IEEE Conference on, Portland, OR, 2013, pp. 114-119.[Abstract]

This work describes the design and implementation of a novel monitoring system for small wind turbines. It is especially suited to small turbines that employ slip-rings between the turbine and tower for power transfer, since it is not practical to retrofit turbines and add more slip rings for transferring monitoring signals. We employ an Arduino based wireless system that measures and transmits the different mechanical and electrical turbine parameters. An Ethernet enabled data acquisition device is used to obtain the data from the receiver for remote data collection. This work was done as part of our Virtual Labs remote laboratories project, providing high quality labs for university students all over the world who do not have access to strong laboratory infrastructure or experienced faculty. The monitoring system is thoroughly described and initial test results are given.

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2013 Conference Paper B. Shankar, Sarithlal, M. K., Vijayan, V., Freeman, J., and Achuthan, K., “Remote Triggered Solar Thermal Energy Parabolic Trough laboratory: Effective implementation and future possibilities for Virtual Labs”, in Control Applications (CCA), 2013 IEEE International Conference on, Hyderabad, 2013.[Abstract]

Virtualisation of experiments is one of the most efficient ways for the modernisation of traditional engineering laboratories. In that context, remote triggering, or remotely controlling actual physical laboratory hardware, is one of the best ways to do this. This paper provides the framework and methodology behind the creation of a Remote Triggered Solar Thermal Energy Parabolic Trough experiment. The `Remote Trigger Solar Thermal Energy Parabolic Trough Lab', is a virtual experiment for analysing the heating capacity of a parabolic trough collector over different flow rates of the heat transfer fluid and for different angles of incidence of radiation. The experiment has a web interface in which the student can view and control the actual hardware device, changing the various parameters which affect the efficiency of the parabolic trough. These parameters can be measured and displayed on the Web interface in a spreadsheet and are plotted in a novel and learning-effective manner. This experiment is being hosted on our VLCAP (Virtual Labs Collaboration and Accessibility Platform) [1] and extensive testing and evaluation is underway. It will be open for a large number of students from all over the world to use the site. This paper presents the implementation strategies and methods used which have proven effective for Virtual Labs, along with a technical description of the experiment and the system used to create and host the experiment.

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2013 Conference Paper B. Shankar, Sarithlal, M. K., Sharat, S., Freeman, J., and Achuthan, K., “Remote triggered virtual laboratory for Hooke's law using LabVIEW”, in Industrial Electronics Society, IECON 2013-39th Annual Conference of the IEEE, 2013.[Abstract]

By the advent of the new millennia there have been notable changes in the way students get their education. Remote triggered labs standout among these education methodologies for their user interaction and active involvement. Remote Triggered Virtual Labs experiments enhance both theoretical and practical learning experience using real time data streaming and analysis. Real time data streaming includes plotting laboratory experiment data values to the user, showing trigger and control buttons and signals and live video streaming of the respective experiment. This paper describes the framework and methodology for the creation of a Remote Triggered Virtual Laboratory experiment for teaching Hooke's Law, a key engineering principle in the Mechanics of Solids. It describes how the experiment works from a technical perspective, how the user interacts with and conducts the experiment, and the novel strategies and methodologies used.

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2012 Conference Paper J. Freeman, Nagarajan, A., Parangan, M., Kumar, D., Dr. Diwakar, S., and Achuthan, K., “Remote triggered photovoltaic solar cell lab: Effective implementation strategies for Virtual Labs”, in Technology Enhanced Education (ICTEE), 2012 IEEE International Conference on, Kerala, 2012.[Abstract]

Remote triggered laboratories are an excellent way to provide access to costly labs and equipment for students in areas without such facilities. A novel remote triggered photovoltaic solar cell experiment is presented here. This experiment enables the student to learn in a hands-on, practical way about the fundamental characteristics of photovoltaic solar cells. The experiment has a web interface in which the student can turn a number of light bulbs on and off, adjust the load voltage of the solar cell, and view the experiment in real-time via a web-cam. In addition, the characteristics of the solar cells under these various conditions are measured and displayed on the web interface in a spreadsheet and are plotted in a novel and learning-effective manner. This experiment has been hosted on our Virtual Labs website for over a year, with a large number of students using the site. This paper presents implementation strategies and methods used which have proven effective for Virtual Labs, along with a technical description of the experiment and the system used to create and host the experiment.

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2011 Conference Paper J. Freeman and Simi, S., “Remote monitoring of indoor environment using mobile robot based wireless sensor network”, in ICCSE 2011 - 6th International Conference on Computer Science and Education, Final Program and Proceedings, Singapore, 2011, pp. 1080-1084.[Abstract]

Remote environmental monitoring is one of the important applications of wireless sensor networking technology where spatially distributed sensor nodes are used to monitor environmental parameters and collaboratively transmit their data through the network. This paper discusses the design of a multi robotic platform within a hybrid wireless sensor network to monitor the environmental changes. The system includes a set of static wireless sensor nodes, a set of mobile robots and a central controller. Mobile robots help to reduce traffic congestions and facilitate close monitoring capabilities. For the effective navigation of the robot, the system uses a known map of the environment, sensor readings and the guidance from the wireless sensor network. The combination of more than one technique for navigation significantly reduces the errors in path planning of the mobile robots. The sensing nodes in the network will forward the accumulated data to the central controller for analysis. The central controller will classify the data based on different threshold levels and records the data. If the system detects an event which exceeds current threshold level, then it will provide an early warning to the authorized users of the system. © 2011 IEEE. More »»
2011 Conference Paper J. Freeman, Omanan, V., and Ramesh, M. V., “Wireless integrated robots for effective search and guidance of rescue teams”, in Wireless and Optical Communications Networks (WOCN), 2011 Eighth International Conference on, Paris, 2011.[Abstract]

Over the past decade, natural and human-induced disasters have claimed millions of lives. Intelligent robots equipped with advanced sensors and integrating wireless networks are attracting attention from researchers and rescuers all around the world. This paper is an application of the Wireless Sensor Network to disaster management. The wireless sensor network consists of two fixed nodes and moving nodes with the robot and rescue teams. The search robot autonomously navigates, searches for living human beings, collects data from the air quality control module, localizes it with respect to the fixed nodes and sends the data. The rescue team can wirelessly receive the data in real time and locate the robot precisely. More »»
2010 Conference Paper S. P Dinesh, Ananthapadmanabha, J., Aravind, V., Nair, A. S., Dutta, S., Vikram, V., Aditya, K., Shankar, B., and Freeman, J., “Low cost and real time electronic speed controller of position sensorless brushless DC motor”, in Information and Automation for Sustainability (ICIAFs), 2010 5th International Conference on, Colombo, 2010, pp. 329-334.[Abstract]

Brushless DC (BDC) motors are widely used in aerospace applications because of their high power to weight ratio, low maintenance and reliable operation over long periods of time. These advantages also make them preferred over brushed DC motors for several other applications. But the requirement of an electronic speed controller for commutation and customization for specific applications makes BDC a costly affair. This paper presents a low cost and real time electronic speed controller for BDC motors. The motor is started using the motor phase saturation inductance change method. Further control of the motor is established by monitoring the back emf zero crossing as a feedback. In addition, MATLAB simulink based simulations have been performed to analyse the circuit performance under real time input conditions. More »»
2010 Conference Paper A. Sa Nair, Aravind, Va, Ananthapadmanabhan, Ja, Dinesh, PaSai, Aditya, Kc, Shankar, Bc, Sheryas, Nc, and Freeman, J., “Innovative dynamic stability control for VTOLs using thrust vectoring”, in Proceedings of the 2010 5th International Conference on Information and Automation for Sustainability, ICIAfS 2010, Colombo, 2010, pp. 317-322.[Abstract]

Single Rotor based Vertical Take Off and Landing systems are more prone to stability issues than normal aircraft. The main factors causing instability are anti torque, pitching and rolling. Anti torque, which causes the body of the aircraft to turn in the opposite direction to the rotor, is generated as the engine turns the rotor against the air. Pitching and rolling, on the other hand, can be caused due to sudden turbulent air conditions during the flight of the aircraft. Today's anti torque mechanisms, like the tail rotors of helicopters, cause the overall system to be bulky and complex. In this paper, a compact automated mechanism is presented which can be used to attain stability in VTOL vehicles. Experimental verification of the system is being performed on a modeled aircraft. Analysis using Velocity Triangles and CFD has been carried out on this system. © 2010 IEEE. More »»
2009 Conference Paper M. V. Ramesh, Vasudevan, N., and Freeman, J., “Real time landslide monitoring via wireless sensor network”, in EGU General Assembly Conference Abstracts, 2009.[Abstract]

Rainfall induced landslides are a common phenomena in the Western Ghat region of Southern India and result in numerous fatalities and damage to property. In order to collect the most relevant and useful data, at the time it is most needed, a wireless sensor network is being used for landslide monitoring. The advantage it gives to landslide monitoringis that it is an inexpensive and reliable way to communicate rapidly over a long distance and inhospitable terrains, collect data in real-time, and alter the data collection rate remotely to suit current environmental conditions. We have implemented a real time landslide monitoring system over a seven acre active complex landslide site. An array of geological sensors (piezometers, tiltmeters, strain gauges, rain gauges, dielectric moisture sensors, geophones) has already been deployed and the data is being automatically collected and forwarded via the wireless sensor network. The geotechnical data is then transferred over 300 km via a satellite link to a remote monitoring station for further analysis. This will give us a better understanding of landslides in this region and prevent the loss of human life. More »»
2009 Conference Paper K. Balasubramanian, Arunkumar, R., Jayachandran, J., Jayapal, V., Chundatt, B. A., and Freeman, J., “Object recognition and obstacle avoidance robot”, in Control and Decision Conference, 2009. CCDC'09. Chinese, Guilin, 2009.[Abstract]

Design highlights of a ldquoThree-wheeled Autonomous Navigational Robotrdquo are presented in this paper. An efficient modular architecture is proposed for ease of adding various modules to the robot. Obstacle detection, pattern recognition and obstacle avoidance are the key aspects of the design. The robot has intelligence built into it that enables it to recognize and pick up balls of a particular colour and ignore other objects in its path. A single board computer mounted on the robot acts as the central controller. It communicates with ultrasonic sensors and motors through multiple microcontrollers and controls the entire motion of the unit. As part of the robot design, a modified H-bridge circuit for driving DC motors efficiently is proposed in this paper. More »»
2008 Conference Paper J. Freeman, Ramesh, M. V., and Mohan, Aa, “Biologically inspired data propagation and aggregation method for wireless sensor networks”, in Proceedings of the 2008 International Conference on Wireless Networks, ICWN 2008, Las Vegas, NV, 2008, pp. 673-678.[Abstract]

This paper presents a novel method of relaying data collected in a directed network towards a sink node. The data is dynamically correlated as the data messages propagate towards the sink node through the network. By simple mathematical means, the "strength" of the data can be increased or decreased based on it's correlation with other encountered data sets. In addition, the strengths of the messages are decayed or automatically reduced each time the data is propagated or relayed towards the sink node (unless it is boosted by correlation with other data). This sets up a dynamic between the strengths of messages being boosted by correlation and being reduced via decay. By letting irrelevant (low strength and uncorrelated) messages die, energy is conserved in the network through reduced message forwarding, congestion, and analysis. This is especially important in wireless sensor networks, where energy consumption should be minimized for maximum network lifetime and reliability. A mathematical model of how to achieve this scenario is presented here. Initial results are given. More »»
2008 Conference Paper J. Freeman, Ramesh, M. V., and Mohan, A., “Biologically Inspired Data Propagation and Aggregation Method for Wireless Sensor Networks.”, in ICWN, 2008.
Publication Type: Journal
Year of Conference Publication Type Title
2014 Journal A. Das, Unnikrishnan, N., Shankar, B., and Freeman, J., “Design, Fabrication and Testing of the Suspension Subsystem of a Single Seater Off-Road Buggy”, International Journal of Applied Engineering Research, vol. 9. pp. 525–536, 2014.[Abstract]

<p>This study deals with the Design, Fabrication and Testing of the Suspension Subsystem of a four wheeled Single Seater off Road Buggy having double wishbone geometry for the front half of the car and a semi-trailing arm geometry for the rear half. Firstly, the design constraints were identified, and then a suitable design model was drawn up with reference to quarter car and half car models. The design was then analyzed statically through ANSYS and dynamically through MSC ADAMS. The suitable design was then fabricated. Finally, the prototype was terrain tested with five on-board tri-axial accelerometers and data acquisition systems to obtain real-time acceleration values on different test conditions along with video imaging for determining wheel and suspension travel.</p>

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2014 Journal J. Freeman, Kiranlal, E. U., and Dharmana, M. Madhu, “ANFIS Based Control Architecture for Solar Energy Heliostats”. 2014.
2013 Journal A. K, Freeman, J., and Udupa, G., “An Intelligent Plant EMG Sensor System for Pre-detection of Environmental Hazards”. 2013.[Abstract]

Environmental disasters are largely unpredictable and occur within very short span of time. Prior detection and warning of environmental disasters is more challenging and very important for survival. Plants are intelligent forms of life that are capable of providing pre- information about environmental hazards avoiding big catastrophe to human kind. Action potentials are a type of electrical signals from the plant that are transmitted along the cell membrane. The plant electrical signal is the reaction of plants to the stimulation or interfering with various conditions of environments. Communication from the plants can be achieved through modulation of the amplitude, frequency change, change in resistance and the rate of propagation of the electrical signal in the plant tissue. The aim of this research is to study and investigate plants response to environmental hazards such as landslides, earth quake, volcanoes or Tsunami etc, by receiving the signals generated from the plants in the nearby areas and to develop an intelligent wireless plant sensor network which can be used to predict the environmental hazards due to changes in the environment. However, as a first step, plant’s response to landslides has been investigated in this paper. The experiments are conducted on the landslide setup to find the responses of the plants to the external stimulations are presented. It is found that the generation of electrical signals from the plant using electromyography sensors (EMG) during the beginning of the landslide gives pre-information which can be detected and communicated through wireless network to prevent the major loss. Keywords: Plant EMG sensor system, Electromyography signals, landslide detection, Plant action potentials.

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Publication Type: Patent
Year of Conference Publication Type Title
2013 Patent G. Sundaram, Freeman, J., and Shanmugam, J., “Integrated Closed-Loop Highly Efficient Renewable Energy System”, U.S. Patent 4480/CHE/20132013.
Publication Type: Journal Article
Year of Conference Publication Type Title
2011 Journal Article J. Freeman and Simi, S., “Robot assisted wireless sensor network for monitoring and detection of explosives in indoor environment”, International Journal on Computer Science and Engineering, vol. 3, pp. 2046–2053, 2011.[Abstract]

In recent years, remote environment monitoring has been significantly improved with wireless sensor networking technology. This paper presents the real time streaming of an indoor environment using a wireless sensor network and a set of self-navigating robots. Mobile robots with mounted sensors will autonomously navigate through an indoor area with unknown obstacles. The robots will be able to avoid obstacles and move around the region. The robots sense the environmental parameters of the region, and send that data to the remote monitoring terminals using an underlying wireless sensor network. This design is applicable to networks where some of the sensors may not have sufficient range to sense data more accurately and closer monitoring is required. Effective path planning for the mobile robot is achieved by combining a map of the area, the sensor readings and the radio strength of the sensor network. Email alerts can be sent to officials if the sensed data goes above a predefined threshold level, thus successfully detecting the presence of explosives in a given area. This system streams the data in real- time to the Internet making it possible for authorized personnel to view the status of the environment online. More »»
Publication Type: Conference Proceedings
Year of Conference Publication Type Title
2007 Conference Proceedings M. V. Ramesh, Raj, R., Freeman, J., Kumar, S., and P Rangan, V., “Factors and Approaches Towards Energy Optimized Wireless Sensor Networks to Detect Rainfall Induced Landslides.”, Proceedings of the 2007 International Conference on Wireless Networks (ICWN’07). CSREA Press, pp. 435-438, 2007.

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