Overview of best sensors designed to build from simple to advanced robots
The robots recognize the environment or perceive objects in its path using several technologies such as laser and sonar sensors, or the traditional vision system represented by digital camera sensors. These little devices that provide images for robotic applications are the subject of this article, where you can find the most used vision camera sensors in robotics as well as tutorials and resources to work with these.
A digital camera sensor represents the vision system that allows any robot to recognize, inspect and analyze large amount of information. Even I talk about a drone that uses cameras to detect potential obstacles, a mobile robot designed to recognize the environment and finding their way to a power plug, or a humanoid robot that recognizes faces, all of these robots uses specialized sensors and highly advanced vision systems.
The machine vision is getting serious to revolutionize the robotic industry including service or industrial applications. If you plan to build the next generation of robots that are able to see like a human, you can start from this article and learn how to interface and program the vision sensors.(more…)
Now, 6 months later after the third generation of Lego Mindstorms was released in stores, with biggest effort the Lego Mindstorms EV3 limits of standard kits were achieved, and there are plenty of reasons to build new software and hardware solutions for new applications.
To prove the dynamism of the Lego community, I explore a long list of software fully compatible with EV3 intelligent brick, as well as an entire list with sensors, controllers, single board computers, and many more components used generally in robotic applications.
Back to the standard building kit, the Mindstorms EV3 has included motors, sensors, and over 550 Lego bricks that can be used in an infinite number of combinations. The brain of the robot is the programmable brick, and you can discover in the following that your robot could become smarter if it used a Raspberry Pi or Arduino single board computers.
The EV3 programming environment is useful for typical customers that work with Lego EV3, but many academic or advanced student users will find it limiting. There is also a solution to use an advanced integrated development environment, and some of these are presented in the following.
In this article, you can find resources for:
- programming the EV3 brick in a variety of languages;
- programming the EV3 using libraries and API’s;
- communicate with the brick using Wi-Fi, Bluetooth, or USB connectivity;
- a series of sensors and robotic parts designed for EV3;
- tutorials to learn few tips and tricks;
- and many more resources out of the EV3 standard pattern;
Autonomous navigation and mapping in robotics making a push in using GPS technology, which is very popular in military and mobile device applications. Based on systems available on the market, there is a ton of GPS modules that can be hard to figure out what you need for your project, and this article is written to get you on the right track in choosing the best GPS module.
In general terms, you can embed a GPS module in a robotic platform when you need the ability to determine its position, or the ability to create a map in a determined space.
Based on these two ways of using GPS module, I find the most used GPS receivers for robotic applications combined with tutorials for practical applications.
What is a GPS?
The GPS (Global Positioning System) has the role to provide exact coordinates of the current location. Widely used in devices such as smartphones, tablets, or GPS navigation devices, the GPS system can be accessible almost everywhere on Earth, and usually it is used in robotic applications for localization and mapping.
A robot can be localized easily using a GPS system that returns the coordinates and a map, or in other way for example, to build a map of a room or at your house.
With a long list of GPS modules available on the market these days, it could be a nightmare to choose one that fit on your project. Based on specifications like accuracy, update rate, or number of channels, you can take the best decision on what system is best for you.
A robot can receive GPS signals via a serial port wired to a GPS system, via Bluetooth from a GPS system, or from a mobile device like a smartphone with a GPS system incorporated.
How Does GPS Work?
Back in time, the first GPS system was used by the U.S. Department of Defense for military navigation, and since then the system has become so popular that it is used in almost all mobile devices and in any autonomous mobile robot with navigation system.
These systems are designed to stay connected anywhere on the planet to at least four GPS satellites. Each of the satellites sends to the GPS system information about its position and the current time at regular intervals. After signals are received by the GPS receiver, the device calculates the distance to each satellite in part based on the time spend for a message to arrive and taking in consideration that the signal travel at the speed of light.
Applying the process called trilateration, the GPS system can pinpoint the location on a map.
Depending on the size, power, update rate, or accuracy, you have to choose the best GPS system for your robot. To make the work easier, in the following I focused and explain some of the most important features of a GPS system.
The ultimate goal when a robot is built is to be optimized and to be compliant with all specifications. To meet the requirements sometimes you can spend many hours just to sort and identify the sensors that would be the best for an application like detecting and tracking an object. In this article, we explore all sensor types that can be used for target detection and tracking as well as features and the types of applications where they can be used.
Selecting the right sensor is not a strict process. This is about eliminating all the wrong choices based on a series of question aiming to eliminate first the technology that underlying the sensor and then the product that it doesn’t fit to the robot requirements.
When we use the word target, we refer in the same time at a small ball, at an object like a chair, or even at a human that stay in front of the robot.
To select the best sensor from a variety of products and manufacturers is a hard work especially when you’re a beginner and try to build a simple robot. In few words the sensor has to be selected in concordance with your targets size, shape and range. All of these three features have to be on the same line with the specification of the robot. But even so, it is hard to define the best sensor since the performance and precision of this depend on many factors.
There are many sensors that can be used for a simple application like line following (IR LED and a Photodiode, LED and LDR, etc.), but this is a simple case when a simple sensor can be selected. A complicated case is when you have to track an object and the budget is limited to purchase a mini computer like Raspberry Pi. In this case it can be used an ultrasonic sensor to scan from side to side till the sensor detect a drop in distance (at this stage it detects the edge of the object and from now on the sensor see only the background). The scanning process continues back to the point where the object is with left and right scanning.
This is one of the cases when expensive products can be replaced with cheap sensors. (more…)
A temperature sensor is not so popular in robotics such as light, infrared, accelerometer, gyroscope, force, or ultrasonic sensors, but they can be useful in rescue and firefighting applications. In the following, you can learn how to interface and programming a wide range of temperature sensors with Arduino, Raspberry Pi, and other electronics.
A temperature sensor is not so popular in robotics, but it is a powerful instrument to measure the temperature in different environments and conditions. Some of the sensors presented in this article are very simple measuring tools, while others are complex sensors that can be used to measure temperature, barometric pressure, and the altitude.
A series of tutorials, guides, and simple examples make the subject of this article, as well as a short overview with specifications for all temperature sensors.(more…)