Lego mindstorm tribot building instructions
We tested the lego mindstorm tribot building instructions and motors in the context of a semester thesis. Afterwards we designed and programmed an own robot that explores an unknown room and stores a map of this room in the Targa TGA image format.
The semester thesis is divided into following subsections: Report on experiences and knowledge gained during work. The first step on our list of lego mindstorm tribot building instructions was to get a profound understanding of NXT's sensors and motors. Of primary interest was the ultrasonic sensor being the only one using digital communication with its own built-in micro-controller.
Despite its generally high accuracy, the sensor seems to have some weak points when measuring certain distances. The remaining sensors were tested as well, although not as extensively as the ultrasonic, the results are shown in the following subsections. In the end we took a closer look a the revised motors, now including rotation sensors. Following Parts of the NXT kit have been tested as part of the semester thesis: To get an idea of the ultrasonic sensor's accuracy and its rounding behavior we examined the sensors behavior towards objects within small distances.
The Object we used was a small cardboard lego mindstorm tribot building instructions Distances smaller than 3 lego mindstorm tribot building instructions can not be measured. The biggest deviance of 2. The sensors mean deviance of 0. The second tests purpose was to gain knowledge of the sensors field of vision.
The same box as in the first test was used It was moved to different distances and angles relative to the ultrasonic sensor while noting the resulting distance readouts. The sensor was placed in horizontal as well as in vertical position, Figure 1. The results show that the ultrasonic sensor should always be placed in horizontal position, other positions decrease as well the field of vision as the sighting distance of the sensor. The sensor seems to be a bit 'blind' on the left eye, which can be explained by the fact that the left eye is actually the receiver of lego mindstorm tribot building instructions ultrasonic wave while the right eye is the sender.
After these experiments on statical behavior of the ultrasonic sensor we moved on to some dynamic tests. The diagram in Figure 1. The data for this diagram was gained by writing a program in LEGO software based on LabView that stored the current ultrasonic value along with the current angle of one of the moving motors we used the TriBot model into a file on the NXT brick.
This file was then downloaded an processed. The dynamic test revealed two weaknesses of the ultrasonic sensor. The first issue is that it showed some areas where the sensor tends to measure cm instead of the actual distance.
The second even more important issue is the critical area in between 25 cm and 50 cm where the sensor has a high probability of returning the wrong value of 48 cm. The primary goal concerning the light sensor was to see to what amount it is able to distinguish different lego mindstorm tribot building instructions. The measurements where done in the sensor's reflected light mode. The results show that the sensor readout depends on the distance of the measured object, which makes it difficult to generally assign certain colors to sensor values.
The touch sensor has been examined towards the force needed to close the touch circuit. Adding weights to the vertical positioned sensor showed that at 34 grams the appears as touched. So in general a force of 0. The motor has been tested towards its linearity between power and rotation speed. A very rudimentary perl script that is able to download a file from the brick has been elaborated and lego mindstorm tribot building instructions available in the Thesis Results section.
The perl script uses the Win As part of the thesis we had to plan and conduct a project. The goal of the project was to build a fancy robot that uses the capabilities of the new "LEGO Lego mindstorm tribot building instructions NXT" generation to the limits of the included sensors and motors. We decided to go for a map building robot that can explore any given room, hence the name Explorer.
The project is divided into following subsections: The walls of the unknown room should be aligned in more or less regular angle to each other.
As concluded by J. Map building Motion planning Collision avoidance Localization These tasks have been implemented separately and in the given order but for the localization function omitted because of lack of time. The program was elaborated through foollowing stages: Explorer 1, Explorer 2 and Explorer 3. A robot deemed fit for the needed requirements was constructed. The robot then travels forward 5 cm and repeats the first step and so on. Motion planning Collision avoidance Start positioning The main idea here was to explore the room in a clockwise direction by always following the wall on the left side.
Once the robot reaches the position it originated from the program stops. The result we achieved with our Explorer project was satisfying. It lego mindstorm tribot building instructions worse tough, the lower the batteries got. The thesis and its Powerpoint summary are written in German and are available for download. Further below are the source code and binary of the explorer project, followed by the perl script to communicate with the NXT brick.
The learning will come from the current robotics literature presented by you and lego mindstorm tribot building instructions fellow students. We will pursue our goal in a spirit of friendly competition: We will enter our robots lego mindstorm tribot building instructions competitions with each other, with the winning robots earning a higher grade for their creators.
To do well in this class, you should have some programming background. Although Computer Science majors will have a slight advantage through familiarity with programming, I have found that the best predictor of success in this course is interest and dedication. Given the intensive spring-term schedule, I expect you to attend every class, having done the reading, and ready to contribute to your team's project.
Barring genuine emergency medical or family or professional commitment job interviewyou will receive a zero on any quiz or deadline that you misswith no opportunity for you to change that grade. Your project writeup should be an approximate page paper lego mindstorm tribot building instructions the issue that your robot is designed to illustrate or explore, showing some experimental results, with instructions on how to replicate these results.
Although you should have enough time to work on your robots during the regular class meetings, I have found that students enjoyed and benefitted from working on their robots outside of class.
Parmlythe room where we will store the robot kits and other material, works well for this purpose. You can borrow a key for this room at the front desk of the Science Library.
Please make sure that the room is locked whenever there is no one in it. Parmly B Office Phone: Your first Mindstorms robot. A Modern ApproachChapter 2 Progress check: Sensors, Signals, Serial, Sockets Project: Work on final project.
Reading Quiz Progress check: Status report on final project. Evolving Neural Networks Project:
Robotics mixed with our beloved bricks, can you ask for more? For some people it is something attractive but at the same time it creates respect and fear: Or is it something frustrating and will I be overwhelmed? In recent years, building and programming robots is changing from being an activity only undertaken by professionals to becoming a leisure activity and a hobby for many people looking lego mindstorm tribot building instructions new technologies as something different from what a video game offers.
The first step in order to begin building and programming robots is to have a general idea of what a robot is, and what the tasks are that we will have to face in their development. That will be the main objective of this article, which will be followed by other articles that may be useful to have a closer look at building and programming. What is a robot? I was fortunate to be part of the technical jury of the of the FLL 1 lego mindstorm tribot building instructions trials that took place in Pamplona in November last year.
When we asked one of the teams what they had learned during the experience of participating in the FLL, the answer was that now they knew what a robot is. Till then, a robot was a machine with legs and arms that could carry out different actions androids. Building and programming a robot taught them that a robot can be much more than just that.
You can find different definitions, and one of them may be: A robot is an electronically controlled mechanical device capable of executing various actions according to a predetermined program and interacting with its environment.
But perhaps the best way to learn about what robotics is the hands on approach, building and programming robots. First, let's see what the common elements that are we will find in all robots. One of the basic parts of a robot is the sensory system, and without it, it cannot perceive its environment, and therefore cannot respond to different stimuli.
The robot receives information through the sensors, which allow it to measure distances, ambient light, noise levels, temperature It has two positions: It can be used in a mobile robot to detect when it hits a wall. Some basic examples are a robot that moves to a brighter area, a robot that detects if a light is switched on in a room and sounds an alarm, or the classic robot that follows a line on the floor. It can measure the distance to an object that is no further than cm. While the touch sensor needs to collide with an object, with the ultrasonic this is no longer needed.
It measures the noise level in the environment and assigns a value to the reading between 1 and It can lego mindstorm tribot building instructions used in different ways, for example, to control a robot with claps, like some home lighting systems. Apart from feeling, the robot must be able to respond to external stimuli, which means, it must be able to do something. In fact, it is possible to design a robot without sensors, but it makes no sense to not be able to do anything, even if only generates sounds.
To be able to do, we can use engines to move, open and close a gripper This makes it a lot easier to control the movements. With the NXT we can connect up to three motors simultaneously. The NXT has three outputs to which we can connect up to three motors and four inputs which allow you to connect up to four sensors. In addition to this there are other ways to communicate with the environment: Everything mentioned before needs a purposeadapted skeleton to support it.
Depending on the desired goal, it could a wheeled vehicle, a biped or quadruped, a of brick organizer depending on their color Especially in the case of mobile robots, it is important to have a strong structure.
A mobile robot that can hit a wall must be built in such a way that is not disassembled during use. But, what is a brain without intelligence? Nothing, so through programming we must define how the robot should behave when facing different stimuli.
Series of blocks sorted according to what you want the robot to do generate a program that is transferred to the NXT, which executes it without the help of the computer.
A step by step example. Our goal is to build and program a robot that moves through a bedroom, corridor The basic process of designing, building and programming a robot is a trial-error-improvement procedure. In Figure 1 you can see an outline of the procedure. When building a mobile robot, first of all we must define what kind of steering system we are going to use: Moving the motors at the same or different speeds will make the robot go straight or turn.
For an easy start it is better to use lego mindstorm tribot building instructions steering. Doing otherwise complicates both the building and programming. Before beginning with the software, no matter which one, we must write the algorithm. What is an algorithm? In this case it might be: Move lego mindstorm tribot building instructions a straight line until you bump into something.
Go back in a straight line for 1 second. Rotate 90 degrees to the left. Start the cycle again. Now that we have the algorithm we can turn it into a language understood lego mindstorm tribot building instructions the robot.
One of the characteristics of NXT-G, unlike other programming languages, is that from the very beginning we can write fully functional programs, without the need of a process of prior lego mindstorm tribot building instructions, and it is aimed at all audiences. A NXT-G program is a sequence of programming blocks attached to a link that simulates a liftarm. The blocks are dragged to the desired position and are linked automatically. In Figure 2 we can see the program for the previous algorithm.
Lego mindstorm tribot building instructions programming block has a panel that allows its configuration. In this program, as shown in Figure 2, only two programming blocks and one control structure are needed. One of the blocks Move is the one that makes the robot go forwards, backwards, turn The control structure determines the flow of the program. In this case, the Loop block repeats the sequence of blocks inside it again and again.
Once we've written the program, we only need to transfer it to the Lego mindstorm tribot building instructions. You have to turn it on and connect it to the computer via Lego mindstorm tribot building instructions cable the fastest and easiest way or via Bluetooth sometimes the configuration lego mindstorm tribot building instructions hard and it is slower.
In Figure 4 you can see the buttons used for the transfer. Now that we have a robot with the program, we need to test it and see if it operates in the desired way. Probably the decisions taken concerning the timing of the back up and turning times did not give the desired result, so after testing we should adjust these times to reach the optimal results. In many cases after testing the robot we should not only change the program but also the assembly: There may be parts that need to rotate or move more fluently For beginners, the best thing to do is to take the guide in the NXT-G software as a starting point.
It offers a series of models with their respective programs described step by step. This will help us understanding the different elements that make up the system, the use of the program editor and will help us to acquiring basic programming skills. Another way, more complicated at the beginning, is to develop our own creations. The ideas can be found around us, on the Internet, or models from other people that may serve as a basis for developing our own.
More information at http: In a later article I will write about the most significant ones. A very interesting source is http: In all the projects it offers only the pieces contained in a Mindstorms set are used and NXT-G is used as the programming language. Login Nuevo password Registrarse. A step by step example Our goal is to build and program a robot that moves through a bedroom, corridor Move in a straight line until you bump into something 2.
Go back in a straight line for 1 second 3. Rotate 90 degrees to the left 4. Start the cycle again Now that we have the algorithm we can turn it into a language understood by the robot. Getting started For beginners, the best lego mindstorm tribot building instructions to do is to take the guide in the NXT-G software as a starting point.