The non-holonomic path deformation method

Nuwani Bandara
Cars that would park automatically or that would be able to manage a stop-and-go mode in traffic jam are potential industrial application of non-holonomic motion planning. A previously planned trajectory may have to be deformed during execution to avoid collisions. There are several reasons for that:

  •       The map  of the environment may be inaccurate
  •         New obstacles may appear that were not in the map
  •          If the planned trajectory is not exactly followed due to a poor localized of the robot,        unexpected collisions may occur

The non-holonomic path deformation method is a generic approach of the online trajectory deformation issue. There are several non-holonomic systems. But the main principal behind them is same. First we need to compute a potential function along the path to the obstacles decreases. Then a direction of deformation is computed in order to make this potential decrease that is for the path to get away from obstacles. The seminal idea of the method is then to establish a relationship between the direction of deformation and the inputs of the system represented by the mobile robot. Then we compute input perturbations that will make the path go in direction of deformation. If we want indeed the deformed path to be feasible by the system, not any path deformation that would make the potential decrease is admissible. The steps of this method is,
a.       Defining a non-holonomic system
b.      Infinitesimal  path deformation
c. Establishment of a relationship between obstacles and path deformation
d.      Take into account the boundary conditions




Bandara W.M.N.N
2950
Member of ENIGMA

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Uses of ultrasonic sensors

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Uses of ultrasonic sensors

Ultrasonic sensors present one of the most cost-effective digital distance measurement systems available for mobile applications.
In industrial applications, ultrasonic sensors are characterized by their reliability  and outstanding versatility. Ultrasonic sensors can be used to solve even the most complex tasks involving object detection or level measurement with millimeter precision, because their measuring method works reliably under almost all conditions.

Triangulation and filtering techniques were used to provide distance and bearing information. A modeling technique based on image processing was used to optimize the arrangement of the sensors. Experimental testing verified the accuracy of the modeling results.
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Robotic Agriculture Machine

Test Website

*A  system with high speed of operation for an advanced agriculture process which includes cultivation based on robotic platform.

*The robotic system is an electro-mechanical and artificial agent which is steered by DC motor which has four wheels.

*The farm is cultivated by the machine, depending on the crop considering particular rows & specific columns.

*The infrared sensor detects the obstacles in the path and it also senses turning position of vehicle at end of land.

*The seed block can be detected and solved using water pressure.

*The machine can be controlled remotely and solar panel is used to charge DC battery.

*Assembly language is used in programming the micro-controllers. The micro-controller is used to control and monitor the process of system motion of vehicle with the help of DC motor.

Algorithm Implementation
1. Start the machine.
2. Select the distance between two columns
3. Display ”Welcome” message on LCD display.
4. Check the whether seed is block or not, if seed is block then water pressure is become ON.
5. If seed box is empty, buzzer ON

W.M.D.L.Wahundeniya
ICT/2012/2013/063
3094
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Save Energy Save Money

Nuwani Bandara
Taking electricity from solar power is a very common topic since from the past. But it is a very common topic nowadays because of the rising electricity bill. That is why people tend to use solar power mostly. Many households and also huge companies use solar power in their daily processes.

Now our government has launched a new project called “Surya bala sangramaya”. From that project you can make money. If you use solar panels at your house, your electricity bill can be reduced. And when your production become higher than usage, your bill will become zero and government will pay you for the extra electricity produced from your solar panels. That electricity will be contributed to the national electricity supply. This project is carried under the Sri Lanka Sustainable Energy Authority.

The method that people are paid for their electricity contribution to the national supply is called as Net Accounting. According to net accounting, people are paid Rs.22 per one unit up to 7 years. From the 8th year, they are paid Rs.15.50 up to 20 years.

There is another method called as Net Plus. From that, people are paid for each and every unit of electricity they produce by their solar panels. That electricity is taken by government. Then the households have to use the electricity produced by the government as in usual way.

Everyone can contribute to energy saving.  You can either select either net plus or net accounting. Hurry up and save the energy!!!


                                                                                  Bandara W.M.N.N
                                                                                  2950
                                                                                 Member of ENIGMA
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Solar energy

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               Solar energy


Solar energy is radiant light and heat from the sun harnessed using a range of ever-evolving technologies such as solar heating, solar photo voltaic, solar thermal energy, solar architecture and artificial photosynthesis.

Solar energy is a renewable resource. A renewable resource is a resource that is able to be replaced or replenished, either by the earth's natural processes or by human action. Solar
energy is available at varying proportions almost everywhere on earth. It cannot be depleted
unlike the fossil fuel based energy resources.
Solar energy is a clean energy resource. It does not involve the emission of Green House Gases (GHGs) that are believed to be responsible for the worsening global warming of our planet, Earth.

Solar energy refers primarily to the use of solar radiation for practical ends. However, all renewable energies, other than geothermal and tidal, derive their energy from the sun. Solar technologies are broadly characterized as either passive or active depending on the way they capture, convert and distribute sunlight. Active solar techniques use photo voltaic panels, pumps, and fans to convert sunlight into useful outputs. Passive solar techniques include selecting materials with favorable thermal properties, designing spaces that naturally circulate air, and referencing the position of a building to the Sun. Active solar technologies increase the supply of energy.



 M.R.F. Rifna
ICT/12/13/078
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Experimental study of Solar Power Grass Cutter Robot

Test Website


There are some experimental grass cutters developed by various countries, various organizations based on solar power energy.


*       Husqvarna-It is an Automatic Mower lives outside, mows when it's programmed to mow and automatically returns to its base for recharging.

*       SN Eno -robot that operates on an on-board, solar charged battery and capability of steering itself across a person’s lawn . This robot called the Atawa A34 , uses built-in infrared sensors to avoid obstacles.

*       Technical Solutions-The design uses an on board computer to control the mower and interact with sensors that guide the robot. The robot has two modes – operation :remote mode in which an individual guides the mower around the outer perimeter of a person’s yard and around any obstacles in its path.

*       Weed Eater-The system is a solar powered emission free mower that harnesses enough power to operate itself. The mower uses this wire along with its sensors to allow the robot to maneuver around while keeping the system on track. The mower will continue to operate as long as the mower has energy, from the sun.

W.M.D.L.Wahundeniya
ICT/2012/2013/063
3094
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Distance Measurement of an Object or Obstacle by Ultrasound Sensors using P89C51RD2

Nuwani Bandara
This is a measurement system which uses ultrasonic transmitter and receiver units mounted at a small distance between them and phillips P89C51RD2 microcontroller based system. This system has been made for the use of robotic sewer inspection system. This system is mounted in the front portion on an automated robotic vehicle. Then the system will compute the distance or location of the obstacle or blockage to the control station above the ground.

An interrupt signal(INT1) initiate the system. When the interrupt INT1is received, MCU start the timer and simultaneously generates the controlled 40KHz ultrasound pulse in the air in the direction of the object. These ultrasonic pulses are reflected from the object and travels back in different directions. When these waves arrived at the receiver, the signals received by the receiver is amplified and processed by receiver module. Receiver module generates an interrupt signal INT2 ; at the instant the first pulse of burst is recovered. INT2 stops the timer 1 and MCU calculates the time between generation and reception of the wave.The measured distance is calculated on the basis of travel time according to a formula.


This system can be easily implemented in other devices and systems requiring the measurement of distance of an object or an obstacle from stationary or moving observation point where the ultrasonic sensor will be located. 

                                                                                                   Bandara W.M.N.N
                                                                                                   AS/12/13/010
                                                                                                   2950
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Obstacle Avoidance with Ultrasonic Sensors

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Obstacle Avoidance with Ultrasonic Sensors 

A robot system, capable of performing various tasks for the physically disabled, has been developed. To avoid collision with unexpected obstacles, the robot uses ultrasonic range finders for detection and mapping. The obstacle avoidance strategy used for this robot is described. Since this strategy depends heavily on the performance of the ultrasonic range finders, these sensors and the effect of their limitations on the obstacle avoidance algorithm.

R.A.N.P. Ranaraja
ICT/12/13/047
3081
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Double axis solar tracker

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 Double axis solar tracker

Design Advantages

Arrangement of module rows at different levels and on two slopes.

-Improved ventilation for the modules,which increases their efficiency and useful life.
-Possibility of adapting any module (standard design for panels maximum length up to 1700 mm).

Other lengths please contact SABO.

-Perfect stability of the assembly and imroved coefficient of wind resistance for the machine.
Self -ventilated arms:
-Elements with airways that enable the heat generated to be dissipated over the parts of the machine.

Effect of the tracker on the efficiency of the inverter

Solar tracker has a positive impact on the total gain of the whole system, making the inverter to work as much time as possible at a better level of performance.

R.A.N.P. Ranaraja
ICT/12/13/047
3081
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Solar Grass Cutter With Linear Blades

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Solar Grass Cutter With Linear Blades

A Solar grass cutter is a machine that uses sliding blades to cut a lawn at an even length. Even more sophisticated devices are there in every field. Power consumption becomes essential for future. Solar grass cutter is a very useful device which is very simple in construction. It is used to maintain and upkeep lawns in gardens, schools, college’s etc. We have made some changes in the existing machine to make its application easier at reduced cost. Our main aim in pollution control is attained through this. Unskilled operation can operate easily and maintain the lawn very fine and uniform surface look. In our project, ―Solar grass cutter‖ is used to cut the different grasses for the different application.
This project is more suitable for a common man as it is having much more advantages i.e, no fuel cost, no pollution and no fuel residue, less wear and tear because of less number of moving components and this can be operated by using solar energy. This will give much more physical exercise to the people and can be easily handled. As we are nearer to Equator, the solar energy (non-conventional energy) is vastly available, so it is easy to charge the battery and is also pollution free. But the initial investments of the solar powered grass cutter is high. At present in order to curtail global warming and ozone depletion, the Government of India is offering subsidy for the solar equipments. The industries are producing these components in mass productions, so the cost of the system may come down. So in future it is expected to run all equipments by using solar energy. This system is having facility of charging the batteries while the solar powered grass cutter is in motion. So it is much more suitable for grass cutting also. The same thing can be operated in night time also, as there is a facility to charge these batteries in day light.

R.A.N.P. Ranaraja
ICT/12/13/047
3081
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