This line follower uses:

• 8 proximity sensor array using phototransistor,
• Microcontroller ATMega16.
• L298 motor driver
• C programming language

Download the document of line follower robot tutorial with ATMega16 HERE

Want to give a special gift for your child? This camera seems to be the right choice. Besides can be used to take pictures, with this camera, the creativity of your child can also more sharply through the lego game.

Lego Digital Camera, so the name of the gadget itself. There are two advantages to be gained from this colorful camera. First, sharpen the creativity of children through the game loading tide. Second, children can learn photography by taking pictures of interesting objects in the vicinity.

Quoted from Gather, Monday (1/3/2010), the specifications presented 3MP camera are:

• 4x digital zoom
• Built-in flash and fixed focus
• 1.5-inch LCD screen
• Capacity of 128MB which can contain up to 80 photos
• USB cable to transfer photos to PC
• Lithium-ion rechargeable battery
• Lego blocks on the top and bottom of the camera
• Has a size of 4″x2, 5″ x1, 5″

This camera can be purchased at a price of 49.99 pound sterling, or about U.S. $ 76.

Note: Lego is one of the companies in the field of robotics and a leader in robotics innovation. Lego often conducted robotics training and robot competitions.

The South Korean government is planning to build “Robot Land”, a research center and recreation, all with robots. That said, this is the first robot park in the world.

Quoted from Cnet, Friday (19/2/2010), this robot island, will be opened in the area of Incheon, one of the largest cities in South Korea. Manufacturing cost is said to reach U.S. $ 560 million.

According to the website “Robot Land”, this robot park will display all forms of entertainment robots nuanced. Eg exhibition famous robots or reconstruction of such a robot movie ‘Minority Report’ or ‘I, Robot’.

Cashier waitress had planned to be a robot. There is also a research center of the robot and robot competition arena. The visitors seemed to be feeling like being on the planet of robots, when entering this “Robot Land”.

Construction of “Robot Land” will begin this year and is expected to be completed in 2013. There will target 2.8 million visitors per year and create 18 thousand jobs because of the “Robot Land”.

“Robot Land” may be one of the event showing off South Korean robot technology. Besides Japan and the United States, this country is one of the leading robot makers.

Recently, Toyota Motor Corp. “attacked” by “storm recall cars” in America, which would make trouble. Not wanting to go on in the problem, Toyota makes a useful pair of robots as human personal assistant.

As reported by Autoevolution, Thursday (28/1/2010), the Japanese car manufacturer announced, if they have created a couple of robots are not just one, but four types of robots!

First is the walking robot, a robot that can walk and is ready to help the parents. The streets were his duty. With two feet and be able to use his hands to perform various tasks. Remarkably, she also can play the trumpet.

Second, the rolling robot. Which can be employed in the factory assembly centers, may eventually be able to help make Toyota cars free recall. He worked very quickly, without requiring much space. He also plays the trumpet.

Third, the transport robot, which can carry passengers anywhere they want to go. But unfortunately, this robot does not have hands and mouth, so it can not play the trumpet.

Last robot is a combination of the three previous robots. He was shorter than the first, has legs, but did not wear a dress like the second, and not like human beings such as the third. This robot was built for a Toyota research.

Interesting, is not it? If later we’ll see and hang out with robots that can walk and drove himself, with trumpet in hand. Is this the future state?

NASA space center diligently to create a humanoid robot astronaut. This sophisticated robot may one day, would replace human tasks when running dangerous missions in space.

Working closely with the General Motors car company, a robot called Robonaut 2 is designed to work side by side with humans. In addition to helping the human astronauts in outer space, Robonaut 2 also would be helped to make cars in the factory.

NASA previously had made the first generation of Robonaut. Robonaut 2 course will be more sophisticated than its predecessor, is designed to work faster, more skilled and stronger construction.

“This sophisticated robotic technology promising something big, not only for NASA but also for the nation,” said Doug Cooke of NASA as detikINET quotes from Computerworld, Friday (5/2/2010).

The United States Government has approved a budget of U.S. $ 3 billion for NASA to develop a variety of robots, especially robots for pioneering space mission. For example a robot that can land on the moon to gather information before humans arrived.

Currently, various types of robots have hired NASA. Robot vehicle called the Phoenix Lander for example, was sent to Mars to conduct research.

Japanese people’s interest against one species of fish were realized by making the recycling robot fish.

Called “recycling” because produced from a number of secondhand items such as raincoats and glass wipers. A researcher and educator in the field of marine named Masamichi Hayashi is the figure behind the robot that called ‘robo-fish’.

Robots that operated with a remote control can perform some activities such as opening and closing the mouth and eat the clone of ‘prey’. In fact, this robot can take the trash out of the water and give it to people who were on the beach.

Hayashi here not only to make a robot fish, but also create a replica other of water animals, such as a turtle with a length of 5 feet and Prehistoric fish coelacanth. And to share knowledge for students, Hayashi has made a series of video documentation of the findings, thus quoted detikInet from the Telegraph.

Robotic surgery has experienced great popularity for urologic surgery; particularly cancers of the prostate located deep in the pelvis.

In 2009, it is estimated that 192,280 new cases will be diagnosed and more than 27,000 men will die of prostate cancer. The lifetime probability of developing prostate cancer is one in six for American men. Current treatment alternatives for clinically localized prostate cancer include removal of the prostate gland (surgery), radiation to the cancerous prostate (external beam or radioactive seed implants), active surveillance, or other treatments (hormonal or cryotherapy).

Radical prostatectomy via an open approach has historically been the gold standard therapy for the surgical treatment of prostate cancer. While oncologic and functional outcomes following open radical prostatectomy are excellent, prolonged recovery is a legitimate concern for physicians and patients. With such considerations, an impetus within the surgical community has been to reduce the complications of procedures without compromising on established standards of care. To that end, laparoscopic surgery, which is performed via several tiny holes rather than one long incision, has been shown to reduce perioperative complications while improving recovery. Robotic surgery represents the next potential iteration for advances in minimally invasive surgery.

The first robotic-assisted surgery performed in 1995 utilized a robotic platform to eliminate the need for an assistant to hold the camera during laparoscopic procedures. The more contemporary da Vinci system represents the next evolutionary step, offering an instrument that can control a camera with one hand while simultaneously manipulating tiny laparoscopic surgical tools in its other hands. With a human surgeon at the controls, da Vinci filters out tremor, enhances precision, offers three-dimensional imaging and may eliminate some of the fatigue associated with conventional laparoscopy.

Robotic surgery appears particularly advantageous from the standpoint of added precision for some procedures. It has experienced great popularity for urologic surgery; particularly cancers of the prostate located deep in the pelvis. Current utilization, however, is quite widespread including applications for general surgery (esophagus, stomach, and biliary reconstruction), cardiac surgery (coronary artery bypass grafting and valve replacement), and gynecology (hysterectomy, oopherectomy, and tubal reconstruction). It is likely that the array of surgical procedures performed with robotic technology only will increase over time.

Starting fall 2009, Penn State Milton S. Hershey Medical Center will be home to the newest robotic system, the da Vinci SI system, and surgeons will be offering this newest surgical advancement to patients in central Pennsylvania.

source: physorg.com
picture: nextgenmd.org

Science fiction movies would have us believe that robotics will soon be dominating our lives. Recent movies like I, Robot and A.I. offer exciting glimpses into a potential future where humans and robots live, but we’re still decades away from that. While giant strides in computers and miniaturization have rooted robotics into mainstream manufacturing and delivery of industrial products, there’s still a lot to learn. We need at least another generation or two before robotic engineering can make robots as common as your PCs at home and in the office.

Simply put, robotics is an allied application of computer science that is more involved in getting programmed instructions to make electro-mechanical devices called robots perform specialized tasks and accomplish results. And achieving that can include using more complex thinking computers that can interact with the environment, people and can move about to make things happen depending on their purposes.

Early Robots
We don’t have to search far to describe an early robotic application. Some of you may remember the jukebox. This is an excellent specimen of crude robotics where you have a mechanical arm programmed to select from an array of 45rpm records the chosen record, get to play its content and then bring it back to where the arm picked it. At home, your record changer is another example and recently CD changers likewise perform the same automated task.

What we have today?
Most robotic applications we have today are found in the manufacture and assembly of automobiles. They take the place of assembly line factory workers who perform specialized tasks, like putting rivets, attaching heavy parts, body painting, etc. In computer manufacturing, robotics also figure a lot in soldering motherboards and other delicate assembly operations. CD and DVD stamping plants have them as well. Robots have been extensively deployed in many production processes considered tedious and repetitive or menial for humans to work in.

It can be said the robotics has its first and most useful application in space and military application. Unmanned spaceships that explored the Martian landscape and went beyond Jupiter are excellent Robotic examples. The same is true with unmanned military aircrafts that perform surveillance on enemy territory.

Even in city streets, surveillance robots have made their presence useful to check buildings and locations where hostile criminal elements are hiding to pinpoint exact location before an attack or arrest is made. Hostile environments like volcanoes have been explored using robots controlled remotely to gather environmental specimens of lava soils and magmatic materials. Robots are now extensively used to explore locations and situations considered risky for human involvement.

Some hospitals are known to deploy special rolling robots that distribute and deliver prescribed medication to patients with programmed location of floors and rooms. They can even be programmed to interface with intelligent hospital elevators to reach any floor and return to the hospital pharmacy for refilling.

What to Expect in the Future
There’s no where else to go but up, so to speak. Robotics will be leveraging on the technological developments in miniaturization and computers to bring robots to the level of interaction with the environment and people to near human cognitive qualities. This, coupled with commercialization to make robots of specific domestic household benefit more affordable, should eventually make it as common as any home appliance.

Source: articlesbase.com

This is an useful report and you could be need this report for your robotics reference. This report contains 3 main parts. Part I deals with the sensors used in mobile robot positioning, while Part II discusses the methods and techniques that use these sensors. The report is organized in 9 chapters.

Part I: Sensors for Mobile Robot Positioning
1. Sensors for Dead-reckoning
2. Heading Sensors
3. Active Beacons
4. Sensors for Map-based Positioning
Part II: Systems and Methods for Mobile Robot Positioning
5. Reduction of Dead-reckoning Errors
6. Active Beacon Navigation Systems
7. Landmark Navigation
8. Map-based positioning
9. Other Types of Positioning
Part III: References and Systems-at-a-Glance Tables

Download the report: Sensors and Methods for Autonomous Mobile Robot Positioning
Download Link I (myfilehost.us)
Download Link II (4shared.com)

This is a very interesting robotic tutorial. You will learn how to build a spy robot (spybot) featured with WiFi connection. This robot needs a network camera and a WiFi router to work as a spy. You need little knowledge of computer networking, especially about Router and IP address configuration.

Visit this page for the tutorial of how to build WiFi SpyBot

Orocos is the acronym of the Open Robot Control Software project. The project’s aim is to develop a general-purpose, free software, and modular framework for robot and machine control. The Orocos project supports 4 C++ libraries: the Real-Time Toolkit, the Kinematics and Dynamics Library, the Bayesian Filtering Library and the Orocos Component Library.

Orocos Libraries
Here the figure of Orocos library:

Orocos is a free software project, hence its code and documentation are released under Free Software licenses.

For more information about Orocos include project history and applications , visit www.orocos.org

The H-Bridge is the link between digital circuitry and mechanical action. The computer sends out binary commands, and high powered actuators do stuff. Most often H-bridges are used to control rotational direction of DC motors. And unless you buy a potentially expensive motor-driver, you need an H-bridge to control any robot with a motor.

This is a quickly sketched H-Bridge circuit with supporting circuitry.

First lets talk about what a transistor is. These nifty chips revolutionized the electronics industry and you would be hardpressed to find something electronic that does not have at least a few thousand of these in them. So what do they do? They can control a flow of electrons by applying a voltage to them. The plumbing equivalent would be a water valve. By rotating the valve, a very large flow of water can easily be controlled.

There are several types of transistors, such as the PNP and NPN, but for sake of making your life easy I will only talk about a MOSFET (Metal-Oxide Semiconductor Field Effect Transistor). These neat things have only been around for a decade or two, but are way better than the more traditional transistor. First they are more efficient. They are easier to calculate mathwise. Plus they usually have built in protection diodes so you don’t need to add them in later. They even have PWM (explained later) optimized MOSFET’s.

So to operate a MOSFET, you apply a voltage to the gate (from your microcontroller), and suddenly a current of electrons passes through the other two pins. Connect a motor (M) in line with one of the pins and your robot is set to go. In the above schematic you will notice the letters A and B. These are your two control lines which you apply this logic voltage to. Since you have two pins, and only a binary control, there are four possible things that can happen.

A=0 B=0 : Nothing happens, the motor is turned off
A=1 B=0 : Motor rotates clockwise
A=0 B=1 : Motor rotates counterclockwise
A=1 B=1 : Your circuit explodes into pretty sparks

Here is a ghetto visual graphic of the H-bridge logic chart:

So now lets talk about how to operate the MOSFET’s. Basically all you need to do is attach the gate to your digital output of your controller. When the digital output is turned on, 5V will be applied to the gate, turning the MOSFET on. However it is better to amplify that 5V to a value higher and I will explain why. The gate voltage controls the MOSFET internal resistance. Zero voltage makes the resistance too high for it to work. A very high voltage has a very low resistance. Resistance leads to loss of energy thermally. This means your MOSFET will heat up and possibly burn out. Take a look at the MOSFET picture above and you will notice my finger print in it. That is what happens when you touch a hot MOSFET – pain! So although you do not need to amplify the gate voltage, it is best to do so. You should also put a heat sink on it.

Ok so what if you want speed control, and not just an on/off switch? PWM! Pulse width modulation. PWM is when you send a square wave at a certain frequency to control the MOSFET as shown above. Basically you are telling your controller to turn on and off the motor at very high rates. So through inductance the motor is neither fully on or fully off, but somewhere in between. Such as at a slower speed. Also a note that motor torque, under PWM, remains the same whether fully on or only a percentage on. However, varying voltage for speed control reduces torque. So with PWM you have maximum torque yet slower speeds! You will have to experiment with wave length for both on and off periods, as well as frequency, to optimize your speed control. But a guess usually works.

Make sure the MOSFET you have has built in protection diodes. If not, install them on your circuit as shown. This is to prevent back currents from your DC motor. Also do not forget to put a small capacitor across the leads on your motor to reduce electronic noise and increase motor life. You might also want to refer to the tutorial on robot power regulation to help you design a better power source for your H-bridge.

It is also recommended to put a slow blow fuse after the power supply, resistors of a few 100 ohms on the gate logic, and the additional capacitors on your circuit as shown. This will prevent melting, large voltage surges, and high frequency emission.

taken from societyofrobotics.com

Morphogenetic robotics generally refers to the methodologies that address challenges in robotics inspired by biological morphogenesis. Morphogenetic robotics includes, but is not limited to the following main topics:

• Morphogenetic swarm robotics that deals with the self-organization of multi-robots using genetic and cellular mechanisms governing the biological early morphogenesis;
• Morphogenetic modular robots where modular robots adapt their configuration autonomously using morphogenetic principles;
• Developmental approaches to the design of the body plan of robots, such as sensors and actuators, as well as the design of the controller, e.g., a neural controller using a generative coding gene regulatory network model

Morphogenetic robotics is related to, but differs from, epigenetic robotics. The main difference between morphogenetic robotics and epigenetic robotics is that the former focuses on self-organization, self-reconfiguration, self-assembly and self-adaptive control of robots using genetic and cellular mechanisms inspired from biological early morphogenesis (activity-independent development), during which the body and controller of the organisms are developed simultaneously, whereas the latter emphasizes the development of robots’ cognitive capabilities, such as language, emotion and social skills, through experience during the lifetime (activity-dependent development). Morphogenetic robotics is closely connected to developmental biology and systems biology, whilst epigenetic robotics is related to developmental cognitive neuroscience emerged from cognitive science, developmental psychology and neuroscience.

Source: Wikipedia

Check above youtube video… that’s Nao Robots playing football. They have ability to detect the ball, kick the ball and when they are falling down to the floor, they could standing up their self…

Nao is definitely one of the coolest humanoids around that stands a chance of making it into households as a real product. Aldebaran envisions it as “an autonomous family companion.”

Fully programmable, the 23-inch bot boasts 25 degrees of freedom, affording it an impressive range of motion. Check it out in Nao’s new promo vid after the jump.

Nao can grasp objects with its prehensile hands; process image and sound data; and navigate its environment using its sonars. Multimedia features include high-fi speakers, microphones, and CMOS digital cameras.

The biped runs on an x86 AMD Geocode 500 MHz CPU, 256MB SDRAM, 2GB flash memory, and lithium polymer batteries that last about 90 minutes per charge.

With striking similarities to Sony’s discontinued Qrio humanoid, you’d think Nao was made in Japan. Pas du tout. Aldebaran is based in Paris, though Nao can only speak English.

Nao robots is for sell, one robot costs about 10.000 €. Do you have a plan to own this Nao robot..?

You can download the video in MP4 format HERE.
Prepare your self for next battle…

_________________

When the legendary science fiction writer Isaac Asimov penned the “Three Laws of Responsible Robotics,” he forever changed the way humans think about artificial intelligence, and inspired generations of engineers to take up robotics.

In the current issue of journal IEEE Intelligent Systems, two engineers propose alternative laws to rewrite our future with robots.

The future they foresee is at once safer, and more realistic.

“When you think about it, our cultural view of robots has always been anti-people, pro-robot,” explained David Woods, professor of integrated systems engineering at Ohio State University. “The philosophy has been, ’sure, people make mistakes, but robots will be better — a perfect version of ourselves.’ We wanted to write three new laws to get people thinking about the human-robot relationship in more realistic, grounded ways.”

Asimov’s laws are iconic not only among engineers and science fiction enthusiasts, but the general public as well. The laws often serve as a starting point for discussions about the relationship between humans and robots.

But while evidence suggests that Asimov thought long and hard about his laws when he wrote them, Woods believes that the author did not intend for engineers to create robots that followed those laws to the letter.

“Go back to the original context of the stories,” Woods said, referring to Asimov’s I, Robot among others. “He’s using the three laws as a literary device. The plot is driven by the gaps in the laws — the situations in which the laws break down. For those laws to be meaningful, robots have to possess a degree of social intelligence and moral intelligence, and Asimov examines what would happen when that intelligence isn’t there.”

“His stories are so compelling because they focus on the gap between our aspirations about robots and our actual capabilities. And that’s the irony, isn’t it? When we envision our future with robots, we focus on our hopes and desires and aspirations about robots — not reality.”

In reality, engineers are still struggling to give robots basic vision and language skills. These efforts are hindered in part by our lack of understanding of how these skills are managed in the human brain. We are far from a time when humans may teach robots a moral code and responsibility.

Woods and his coauthor, Robin Murphy of Texas A&M University, composed three laws that put the responsibility back on humans.

Woods directs the Cognitive Systems Engineering Laboratory at Ohio State, and is an expert in automation safety. Murphy is the Raytheon Professor of Computer Science and Engineering at Texas A&M, and is an expert in both rescue robotics and human-robot interaction.

Together, they composed three laws that focus on the human organizations that develop and deploy robots. They looked for ways to ensure high safety standards.

Here are Asimov’s original three laws:

• A robot may not injure a human being, or through inaction, allow a human being to come to harm.
• A robot must obey orders given to it by human beings, except where such orders would conflict with the First Law.
• A robot must protect its own existence as long as such protection does not conflict with the First or Second Law.

And here are the three new laws that Woods and Murphy propose:

• * A human may not deploy a robot without the human-robot work system meeting the highest legal and professional standards of safety and ethics.
• A robot must respond to humans as appropriate for their roles.
• A robot must be endowed with sufficient situated autonomy to protect its own existence as long as such protection provides smooth transfer of control which does not conflict with the First and Second Laws.

The new first law assumes the reality that humans deploy robots. The second assumes that robots will have limited ability to understand human orders, and so they will be designed to respond to an appropriate set of orders from a limited number of humans.

The last law is the most complex, Woods said.

“Robots exist in an open world where you can’t predict everything that’s going to happen. The robot has to have some autonomy in order to act and react in a real situation. It needs to make decisions to protect itself, but it also needs to transfer control to humans when appropriate. You don’t want a robot to drive off a ledge, for instance — unless a human needs the robot to drive off the ledge. When those situations happen, you need to have smooth transfer of control from the robot to the appropriate human,” Woods said.

“The bottom line is, robots need to be responsive and resilient. They have to be able to protect themselves and also smoothly transfer control to humans when necessary.”

Woods admits that one thing is missing from the new laws: the romance of Asimov’s fiction — the idea of a perfect, moral robot that sets engineers’ hearts fluttering.

“Our laws are little more realistic, and therefore a little more boring,” he laughed.

source: sciencedaily.com

This line follower robot is very small and simple. This robot is running fast and follow the line very smoothly. You may see the video here.

Mechanics

All mechanical and electrical parts are mounted on a proto board, and it also constitutes the chasis.

The line following robot is upheld in three points of two driving wheels and a free wheel. The driving wheels are made with a 7 mm dia ball bearing and a rubber tire. The free wheel is a 5 mm dia ball bearing attached loosely. To drive driving wheels, two tiny vibration motors that used for cellular phone, pager or any mobile equipment are used. Its shaft is pressed onto the tire with a spring plate, the output torque is transferred to the wheels.

The steearing mechanism is realized in differential drive that steear the robot by difference in rotation speed between the left wheel and the right wheel. It does not require any additional actuator, only controling the wheel speed will do.

Line detector and Photo reflector

To detect a line to be followed, most contestants are using two or more number of poto-reflectors. Its output current that proportional to reflection rate of the floor is converted to voltage with a resister and tested it if the line is detected or not. However the threshold voltage cannot be fixed to any level because optical current by ambent light is added to the output current like the image shown right.

Most photo-detecting modules for industrial use are using modurated light to avoid interference by the ambient light. The detected signal is filtered with a band pass filter and disused signals are filtered out. Therefore only the modurated signal from the light emitter can be detected. Of course the detector must not be saturated by ambient light, this is effective when the detector is working in linear region.

In this project, pulsed light is used to cancel ambient light. This is suitable for arraied sensors that scanned in sequence to avoid interference from next sensor. The microcontroller starts to scan the sensor status, sample an output voltage, turn on LED and sample again the output voltage. The difference between the two samples is the optical current by LED, output voltage by the ambient light is canceled. The other sensors are also scanned the same avobe in sequence.

Line Detection Signal Processing

Right image shows the actual line posisiton vs detected line position in center value of 640. The microcontroller scans six sensors and calcurates the line position by output ratio of two sensors near the line. Thus the line position can be detected lineary with only six sensors. All the sensor outputs are captured as analog value that proportioning to reflection ratio, and the sensitivity have variety between each one of them. In this system, to remove the variations from the outputs, calibration parameters for each sensor can be held into non-volatile memory. This can be done with online mode. The microcontroler enters the online mode when an ISP cable is attached, and it can be controlled with a terminal program in serial format of N81 38.4kbps. S1 command monitors sensor values, and S2 command calibrates variation of sensor gain on the reference surface (white paper). The ATmega8 must be set to 8MHz internal osc.

Tracking Control

The line position is compeared to the center value to be tracked, the position error is processed with Proportional/Integral/Diffence filters to generate steering command. The line folloing robot tracks the line in PID control that the most popular argolithm for servo control.

The proportional term is the commom process in the servo system. It is only a gain amplifire without time dependent process. The differencial term is applied in order to improve the responce to disturbance, and it also compensate phase lag at the controled object. The D term will be required in most case to stabilize tracking motion. The I term is not used in this project from following resons. The I term that boosts DC gain is applied in order to remove left offset error, however, it often decrease servo stability due to its phase lag. The line following operation can ignore such tracking offset so that the I term is not required.

When any line sensing error has occured for a time due to getting out of line or end of line, the motors are stopped and the microcontroller enters sleep state of zero power consumption.
Notes:

• Development diary [Ja]
• Circuit diagram
• Firmware May 23, 2004
• Following motion with only P control
  This is a video file of line following motion with only P control. The servo system oscllated.
• Following motion with P and D controls
  Adding D control could improve the servo stability. The robot follows the line correctly. Therefore the servo parameter must be optimized for mechanical characterristics to improve the tracking stability.

Source: elm-chan.org

Built based on PIC microcontroller, this robot has multi functions, you might use this robot for several objectives.

The robot’s objectives are the following:

1. Follow a line with sharp turns
2. Maneuver through breaks in the line
3. Detect obstacles and manuever around them
4. Identify colors to be able to locate green and aluminum victims.

You can find the complete tutorial here

Artificial bacterial flagella are about half as long as the thickness of a human hair. They can swim at a speed of up to one body length per second. This means that they already resemble their natural role models very closely.

They look like spirals with tiny heads, and screw through the liquid like miniature corkscrews. When moving, they resemble rather ungainly bacteria with long whip-like tails. They can only be observed under a microscope because, at a total length of 25 to 60