Archive for the ‘Robots’ Category
How to Make a Robot – Lesson 2: Choosing a Robotic Platform
Posted on August 12th, 2010 in Articles, How To Make a Robot, Projects, Robots- Lesson 1 – Getting Started
- Lesson 2 - Choosing a Robotic Platform
- Lesson 3 - Making Sense of Actuators
- Lesson 4 - Understanding Microcontrollers
- Lesson 5 - Choosing a Motor Controller
- Lesson 6 – Controlling your Robot
- Lesson 7 - Using Sensors
- Lesson 8 - Getting the Right Tools
- Lesson 9 - Assembling a Robot
- Lesson 10 - Programming a Robot
- Land wheeled, tracked, and legged robots
- Aerial planes, helicopters, and blimp
- Aquatic boats, submarines, and swimming robots
- Misc. and mixed robots
- Stationary robot arms, and manipulators
Wheeled Robots
Wheels are by far the most popular method of providing mobility to a robot and are used to propel many different sized robots and robotic platforms. Wheels can be just about any size, from a few centimetres up to 30 cm and more . Tabletop robots tend to have the smallest wheels, usually less than 5 cm in diameter. Robots can have just about any number of wheels, although 3 and 4 are the most common. Normally a three-wheeled robot uses two wheels and a caster at one end. More complex two wheeled robots may use gyroscopic stabilization. It is rare that a wheeled robot use anything but skid steering (like that of a tank). Rack and pinion steering such as that found on a car requires too many parts and its complexity and cost outweigh most of its advantages. Four and six wheeled robots have the advantage of using multiple drive motors (one connected to each wheel) which reduces slip. Also, omni-directional wheels or mecanum wheels, used properly, can give the robot significant mobility advantages. A common misconception about building a wheeled robot is that large, low-cost DC motors can propel a medium sized robot. As we will see later in this series, there is a lot more involved than just a motor.Advantages
- Usually low-cost compared to other methods
- Simple design and construction
- Abundance of choice
- Six wheels or more rival a track system
- Excellent choice for beginners
Disadvantages
- May lose traction (slip)
- Small contact area (only a small rectangle or line underneath each wheel is in contact with the ground)
Tracked Robots
Tracks (or treads) are what tanks use. Although tracks do not provide added “force” (torque), they do reduce slip and more evenly distribute the weight of the robot, making them useful for loose surfaces such as sand and gravel. Also, a track system with some flexibility can better conform to a bumpy surface. Finally, most people tend to agree that tank tracks add an “aggressive” look to the robot as well.Advantages
- Constant contact with the ground prevents slipping that might occur with wheels
- Evenly distributed weight helps your robot tackle a variety of surfaces
- Can be used to significantly increase a robot’s ground clearance without incorporating a larger drive wheel
Disadvantages
- When turning, there is a sideways force that acts on the ground; this can cause
damage to the surface the robot is being used on, and cause the tracks to wear - Not many different tracks are available (robot is usually constructed around the tracks)
- Drive sprocket might significantly limit the number of motors that can be used.
- Increased mechanical complexity (idler placement and number, # of links) and connections
Legs
An increasing number of robots use legs for mobility. Legs are often preferred for robots that must navigate on very uneven terrain. Most amateur robots are designed with six legs, which allow the robot to be statically balanced (balanced at all times on 3 legs); robots with fewer legs are harder to balance. The latter require “dynamic stability”, meaning that if the robot stops moving mid-stride, it might fall over. Researchers have experimented with monopod (one legged “hopping”) designs, though bipeds (two legs), quadrupeds (four legs), andhexapods (six legs) are the most popular.Advantages
- Closer to organic or natural motion
- Can potentially overcome large obstacles and navigate very rough terrain
Disadvantages
- Increased mechanical, electronic and coding complexity (not the easiest way to get into robotics).
- Lower battery size despite increased power demands
- Higher cost to build
Advantages
- Remote controlled aircraft have been in existence for decades (so there is a large community, at least for the mechanics)
- Excellent for surveillance
Disadvantages
- The entire investment can be lost in one crash.
- Limited robotic community to provide help for autonomous control
Advantages
- Most of our planet is water, so there is a lot to explore and discover
- Design is almost guaranteed to be unique
- Can be used and/or tested in a pool
Disadvantages
- Robot can be lost many ways (sinking, leaking, entangled…)
- Most electronic parts do not like water (also consider water falling on electronics when accessing the robot after a dive)
- Surpassing depths of 10m or more can require significant research and investment
- Very limited robotic community to provide help
- Limited wireless communication options
Advantages
- Designed and built to meet specific needs
- Multi-tasking and can be comprised of modules
- Can lead to increased functionality and versatility
Disadvantages
- Possible Increased complexity and cost
- Often times, parts must be custom designed and built
Advantages
- Very simple to very complex design possibilities
- Easy to make a 3 or 4 degree of freedom robot arm (two joints and turning base)
Disadvantages
- Stationary unless mounted on a mobile platform
- Cost to build is proportional to lifting capability
How to Make a Robot – Lesson 1: Getting Started
Posted on August 4th, 2010 in Articles, Hobbyist, How To Make a Robot, Projects, RobotsLessons Menu:
- Lesson 1 – Getting Started
- Lesson 2 - Choosing a Robotic Platform
- Lesson 3 - Making Sense of Actuators
- Lesson 4 - Understanding Microcontrollers
- Lesson 5 - Choosing a Motor Controller
- Lesson 6 – Controlling your Robot
- Lesson 7 - Using Sensors
- Lesson 8 - Getting the Right Tools
- Lesson 9 - Assembling a Robot
- Lesson 10 - Programming a Robot
Getting Started
Welcome to the first installment of the Grand RobotShop Tutorial, a series of 10 lessons that will teach you how to make your own robot. This tutorial is aimed at anybody willing to get started in robotics and have a basic understanding of terms such as “voltage”, “current”, “motor”, and “sensors”. Although this might seem pretty basic, even people with previous robot building experience might find useful information regarding the general method of building a robot.
What is a robot?
There are many definitions of robot and no real consensus has been attained so far. We loosely define a robot as follows:
Robot: An electromechanical device which is capable of reacting in some way to its environment, and take autonomous decisions or actions in order to achieve a specific task.
This means that a toaster, a lamp, or a car would not be considered as robots since they have no way of perceiving their environment. On the other hand, a vacuum cleaner that can navigate around a room, or a solar panel that seeks the sun, can be considered as a robotic system.
It is also important to note that the “robots” featured in Robot Wars for instance or any solely remote controlled device would not fall under this definition and would be closer to a more complex remote controlled car.
Although this definition is quite general, it might need to evolve in the future in order to keep up with the latest advancement in the field. In order to get a sens of how robotics is rapidly growing, we suggest you take a look at the RobotShop History of Robotics.
Let’s get started
This series of tutorials is intended to guide you through the steps of building a complete mobile robot.
There are 10 lessons that will be released in the following 10 weeks. Each lesson guides you through one step of making a general-purpose mobile robot. This will enable you to build your very own mobile robot in order to perform a task of your choice. Each lesson will be illustrated with an example from RobotShop experience in producing the RobotShop Rover. The lessons are intended to be read one after the other and build upon the information gained.
STEP 1
The first step is to determine what your robot should do (i.e. what is its purpose in life). Robots can be used in almost any situation and are primarily intended to help humans in some way. If you are unsure of what you want your robot to do or simply want to concentrate your efforts on specific tasks, here are some ideas:
Knowledge & Learning
In order to build increasingly complex robots, most professionals and hobbyists use knowledge they have acquired when building previous robots. Instead of building one robot, you can learn how to use individual components with the objective of building your own “knowledge library” to use to undertake a larger, more complex design in the future.
Amusement & Companionship
Building a robot is in and of itself is fun and exciting. Robotics incorporates aspects of many disciplines including engineering (mechanical, electrical, computer), sciences (mathematics and physics) and arts (aesthetics) and users are free to use their imagination. Amusing others with your creations (especially if they are user-friendly and interactive) helps others to become interested in the field.
Competitions & Contests
Competitions give the project design guidelines and a due date. They also put your robot against others in the same class and test your design and construction skills. Although many competitions are specifically for students (elementary to university), there also exist open competitions where adults and professionals alike can compete.
Autonomous life form
Humans are natural creators and innovators. The next great innovation will be to develop a fully autonomous life form that rivals or surpasses ourselves in ability and perhaps creativity. This goal is still being accomplished in small steps by individuals, research organizations and professionals.
Domestic or Professional tasks
Domestic robots help liberate people from unpleasant or dangerous tasks and give them more liberty and security. Professional and Service Robots are used in a variety of applications at work, in public, in hazardous environments, in locations such as deep-sea, battlefields and space, just to name a few. In addition to the service areas such as cleaning, surveillance, inspection and maintenance, we utilize these robots where manual task execution is dangerous, impossible or unacceptable. Professional and Service Robots are more capable, rugged and often more expensive than domestic robots and are ideally suited for professional and/or commercial use.
Security and Surveillance
Most mobile robots are used to venture into areas where humans either should not or cannot go. Robots of various sizes (either remote controlled, semi-autonomous or fully autonomous) are an ideal choice for these tasks.
Practical Example
We anticipate that most of you following this guide have the objective of building a robot for learning and knowledge, but also for sheer fun; though many will have a specific idea or project they want to materialize.
The last major consideration is budget. It is difficult to know exactly what people have in mind when they build their first robot; one might already want to build an autonomous snow removal robot, while another simply wants to make an intelligent clock. A simple programmable mobile robot might cost about $100 while a more complex can be several thousands of dollars.
In this exercise, we have chosen to make a mobile platform in order to get an understanding of motors, sensors, microcontrollers and programming, and to include a variety of sensors. We’ll keep the budget to about $200 to $300 since we want it to be fairly complete.
For further information on learning how to make a robot, please visit the RobotShop Learning Center. Visit the RobotShop Community Forum in order to seek assistance in building robots, showcase your projects or simply hang-out with other fellow roboticists.
DFRobotshop Rover Or Arduino On Tracks
Posted on July 29th, 2010 in Hobbyist, News, Projects, Robots
RobotShop is proud to announce the immediate availability of the DFRobotShop Rover, an Arduino-compatible robotic tracked platform. At an 89.99 USD price-tag, this is by far the most affordable, programmable mobile robot in the market.
The DFRobotShop Rover is a versatile mobile robot tank based on the popular Arduino Duemilanove. It incorporates all the Duemilanove features (since it uses a surface mount ATMega328), including shield compatibility, and is supplemented with (1) an on-board DC step-up that allows it to be easily powered from small power sources such as AA batteries, (2) a dual H-bridge DC-motor controller (L293B), and (3) an APC220 and Bluetooth serial interface connector for telemetry and radio control. As an addition it also features a temperature and light sensors that can be readily connected to analog inputs on the ATMega328 for immediate use. This Arduino-compatible platform rides on the popular Tamiya twin motor gearbox and the Tamiya track and wheel set. This created a low-cost traction system that has been tested to carry over 2 kg without issues.
Let us know what would you like to do with this very cool Arduino tank.
Via RobotShop Blog.
Lego Mindstorm NXT + Arduino
Posted on July 23rd, 2010 in Articles, Hobbyist, Motors, RobotsClinton Blackmore form the Southern Alberta Robotics Enthusiasts club put together some pretty neat software to control Lego NXT motors and sensors by using the Arduino microcontroller.
He is using the Mindsesors Multiplexer for NXT Motors coupled with an Arduino Compatible Seeeduino in order to control a small robot made from Lego NXT parts, read NXT encoders, and more. The code for the Arduino can be found in the NXT I2C Devices For Arduino Project Page.
The possibilities that this enables are almost endless. Especially when considering that now Arduino Shields can be used in order to extend the capabilities of the Lego NXT parts.
Via RobotShop Blog.



















