[MAVLink] Introduction to MAVLink, Ardupilot and its Hardware Systems

Sulaiman Rehema salat wa salam ala nabina muhammad wa ala alihi wa sahbihi ajma'in in this presentation i'm going to provide a brief introduction and overview about the mapping protocol ardupilot and ground stations so what is the mapping protocol the mapping protocol is simply a communication protocol that allows an unmanned vehicle like a copter a drone or a rover to communicate with the ground station so the vehicle will send messages to the ground station that allows the ground station to monitor the status and for example follow the position of the vehicle and also the ground station concerned also messages to the vehicle in order to perform some actions for example moving from one point to another so the mapping protocol was first released in 2009 by Lawrence Meyer and the LGPL license and this protocol basically specifies a set of messages and their structures and formats and how they are exchanged between the vehicle and the ground station so looking at this figure here we can see a drone and a ground station so this drone concerned map link messages to the ground station and here we can see an example of GPS coordinate message that can be sent from the drone to the ground station and the letter will parse the incoming message and then find the position to visualize the location of the drone into the map and of course there are several types of public messages that we are going to discover in future videos so there is a point-to-point connection between the drone and the ground station usually this connection happens through a wireless connection or serial connection using telemetry devices or UDP protocol or TCP protocol and then a set of messages are exchanged continuously between the ground station and the drone in order to monitor and control the state of the unmanned vehicle so typically the protocol is implemented inside the autopilots and these autopilots governs the control and the motion of the drone and the most common autopilot for drones and for unmanned vehicles is the autopilot so ardupilot is a full-featured and reliable autopilot software it allows to control the vehicle system autonomously it has been developed over five years by a team of divers professional engineers computer scientists this autopilot is capable of controlling any vehicle system including planes multi-roters like quad copters or octocopter or helicopters and also ground vehicles and underwater vehicles like boat and submarine robots so these are the pilot supports the mapping protocol as previously said and has advanced data logging analysis and simulation tools that allows the developer to analyze the behavior of the unmanned vehicle after completing a mission the r2 pirate was initially developed for the 8-bits microcontrollers and now is being optimized to use with 30 bits erm microcontrollers and it can also run under Linux and single board computers our tow pilot supports several types of vehicles including ground vehicles rubber planes and also multicopters supporting different ones what copters octocopter and it has also three copters helicopters different types of vehicles so there is a complete stack for copters and different stack for planes and different stack for reverse all of them are included in our tow pilot for the APM copter it is an open-source multicopter UAV controller it supports any kind of multicopter and helicopters including quad copters supports different frame type for the multicopters and it was the spark front 2013 and 2014 autonomous vehicle competition there is another stack that is called a PM plane this is for exit wink aircrafts it provides advanced functionalities for planes and for hundreds of three-dimensional waypoints automatic take-off and landing and also sophisticated mission planning and camera controls the third type is the APM Rover it also provides an advanced at open source autopilot for guiding ground vehicles and boats it can run fully autonomously it can execute autonomous missions that are defined using a mission planner software which we are going to discover in a few slides and this one also won the 2013 and 2014 spurt from autonomous vehicle competition now let's talk about the common autopilot hardware so as you can see in this figure there are several common autopilot hardware the most popular and probably the older one is the pixhawk and pixhawk is an independent open hardware project aiming at providing high-end autopilot hardware to the academic hobby and industrial communities at low cost and high availability so the total cost of pixhawk alone without accessories is around $100 and it was originated from the pixhawk project and the computer vision and geometry lab of th zurich in switzerland and the autonomous system lab this autopilot module runs a very efficient real-time operating system this is the artists operating system which provides a POSIX style environment and the software can be updated with the USB boot loader and now very recently there has been the release of pixhawk 2 which is an extension of pixhawk with more elaborated features including vibration isolation and three integrity I amuse with better connectors and pixhawk to flight controller has been designed by the pixhawk open hardware community as well in collaboration with 3d robotics and was first released as the autopilot of the 3dr solo drone and it has similar features to the original version of pixhawk so the third autopilot that we present is the nub u2 which is a Linux autopilot that operates on top of a Raspberry Pi so allow you to visit not a pilot board or shield that can be plucked onto a Raspberry Pi 2 or Raspberry Pi 3 and works under the Linux operating system and Navi runs when the proven a p.m. flight stack and the code is executed directly on the Raspberry Pi with real-time Linux kernel and run also for copter plane and rover as well it supports the map link communication protocol with a wide variety of ground stations from Windows Mac and Linux as well the good point in w2 is that it has Internet connectivity and it's possible to use LTE 4G 3G modem or higher power Wi-Fi to make the drone accessible through the internet or on the local area network it's also possible to stream video from a Raspberry Pi camera to use a joystick to control the drone from anywhere in the world the combination between w2 and Raspberry Pi makes it a very suitable autopilot for low-cost drones so the cost of nagato platform is around 160 dollars in the raspberry pi around 30 to 40 dollars so in total it's around $200 which makes more power for auto pilots as compared to pigs folk because pigs hog doesn't have a computer board but also it can be integrated with a single board computer like Raspberry Pi or also although it Xu for the fourth platform is early brain 2 which is also similar to Nebu - so the first version of early brain it worked on eaglebones single board computer and early brain till the second version it works on Raspberry Pi zero so this platform is as I mentioned similar to nav YouTube platform has gravity sensors gyroscope digital compass pressure sensors temperature sensors the early brain to also operate on top of Linux operating system and has an integrated so this platform also supports the mapping protocol for communication between the drone and ground station and also supports rush through the Mavros protocol that is an additional layer on top of the map link that connects my bling toros so the developer will be able to develop cross programs that allows us to communicate with the ardupilot autopilot stack the last platform in the figure is the pxf mini which is the low-cost and open autopilot sheet for the Raspberry Pi that allows to create ready to fly autopilot with support for encodes a p.m. flight stop the shield has been designed specifically for the Raspberry Pi zero but it is also compatible with other boards like the Raspberry Pi 2 and Raspberry Pi this figure shows the possible connections with the pixhawk autopilot platform so the pixhawk can be connected to several accessories and devices it can be connected to a buzzer to provide audio signals that indicate what the AV is doing it can also be connected to a safety switch that allows the operator to safely power down the UAV pigs heart is also connected to telemetry devices through the telemetry you are port there are two ports for telemetry telemetry one and telemetry two and the telemetry provides a secondary means of controlling the UAB it can allow you to work with all four grantstation software in real time and there are two types of telemetry some telemetry works on 915 megahertz frequency band and others on the frequency band 433 megahertz which are designated for Europe the first one for the USA and telemetry allows long-range communication between the ground station and the autopilot which can reach up to two to five kilometers depending on communication range of the telemetry device in addition the autopilot is connected to the motors of the copter and usually the connection is done through the ESC module and ESC stands for electronic speed controller it allows to provide control signals to the motors according to the input signals received by the autopilot so as you can see here for the several connections there are several pins or to connect the motors to them and through this piece PWM signals are going to be sent to the electronic speed controller and then will be transferred to the motors according to the put signal in addition to that the autopilot is powered by lipo battery and there is a power module that allows to make required voltage and current conversion usually the lipo batteries operate at 12 volts and the peaks folks wait voltage of five points so there is a power that makes and also the power module allows to provide power to the motors through the ESC it's also recommended and possible to use a battery tester which provide an audio alarm whenever the battery goes below predefined level and here in the autopilot you can see an auto that indicates the forward direction of the autopilot so usually this arrow and decades the forward direction in the x-axis which should follow the same direction of the arrow the autopilot is also connected to a receiver and these receivers receives input control commands from the remote control and the receiver takes the 2.5 gigahertz signals from the transmitter which is the remote control the autopilot also has an i2c port that allows to connect an external compass and also it has another port what is the GPS port that allows to connect an external GPS and here when you connect the GPS you have to make sure that the arrow of the GPS is in the same direction of the arrow of the autopilot platform and this also need to be configured in the calibration phase of the compass so typically the pixhawk has an internal compass but kid it can also be overwritten by an external compass which is usually embedded with the GPS like the 3dr GPS compass device and in some cases we might have only GPS without compass can also be connected to the GPS port only it is recommended to have an external compass because usually we can put the external compass far from the interference occurring inside the ball which will result in a more stable flight experience you can also see that we can have a ground station that can be either on a tablet or on a computer machine that is connected to the autopilot through device and this telemetry device will be able to communicate through the telemetry device that is connected to the autopilot to send and receive monthly messages between the autopilot and the ground station the communication between the ground station and the autopilot does not necessarily occur through a telemetry device but it can also occur through a local area network using Wi-Fi but the range will be much smaller in this case this figure summarizes the main ports of a pixhawk autopilot platform so pixhawk is characterized by one hundred sixty eight megahertz cortex CPU with 256 gigabyte of RAM and 2 megabyte of flesh it has different types of sensors including 3d accelerometer gyroscope and magnetometer and also a barometer it contains a micro SD slot and 5u our ports can port 1 AI 2 C port wine spi port and one ADC port and several others so similar to pixhawk Nibiru is also an autopilot but this top pilot is actually a shield for the Raspberry Pi it operates on Raspberry Pi 2 which is a quad-core 1 gigahertz single board computer that runs on real-time Linux and also contains the a p.m. flight stack there is an e p.m. flight stack strictly configured for Navi 2 so the advantage of nagato is that it contains an integrated GPS receiver and this GPS receiver it has an external antenna in addition to that it has dual IMU so it has two IMU integrated devices and this daily tendency is to improve the flight performance so the first IMU is the MTU 9250 it has land agree of freedom and the second IMU is the LSM 90 as one which also has nine degree of freedom so this redundancy is actually good for improved flight performance furthermore it has an integrated input/output processor which accepts important provides 14 PWM outputs channels with variable frequencies so here we have 40 inputs where we can connect the and motors and easy to them it also has a tripod redundant power supply so a power supply for Navy two can be put directly from a battery or also it can be drawn Raspberry Pi our can be powered from the Raspberry Pi it has also different extension ports including uart port I to support and also a DC ports or interfaces with sensors and radios furthermore it has a high resolution barometer so this is the barometer it's not altitude with ten centimeters resolution and this barometer allows to estimate the altitude to the ground and it is actually recommended that this barometer is covered with a certain form so that avoid interference and airflow to compromise the operation of the barometer

Channel: Anis Koubaa

Views: 32,379

Keywords: Ardupilot, MAVLink, Pixhawk, Pixhawk2, Navio22, PXFMini, Erle Brain, Drone, Copter

Id: qLfxzeKu2Hg

Length: 16min 16sec (976 seconds)

Published: Fri Nov 11 2016