Questions tagged [quadcopter]
A quadcopter, also known as a quadrotor, is a multirotor helicopter that is lifted and propelled by four rotors.
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Cascaded PID controller implementation
For a project I am building and programming my own flight controller. I have seen the implementation of a single loop PID controller. But after doing some more research I've found that a cascading PID ...
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How to decide the drag constant of motors?
Hi I'm current working on building an AUV, and I'm calculating the allocation matrix for my dynamic system. But I don't know how to model the drag momentum of motors.
I know in UAV, they model it by ...
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Move a Simulated Quadcopter in a straight line
I'm trying to move a quadcopter in a simulator from (x0, y0) to (x, y) in a straight line at a constant speed. The simulator takes x and y inputs in m/s. Altitude as an input is a constant value in ...
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What is the consquence of Gimbal lock?
I'm learning about Gimbal lock and I understand the reason why that happened.
But I don't understand why that is a big deal because it only affect this rotation. After this rotation finished, we have ...
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SMC: Is there a way to control two sliding surfaces with just one control input?
This is a question related to Control Systems.
I've been searching papers all over the internet with very little success. I know that traditionally we want one control per sliding surface but If ...
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Uncontrolled drift of Visual Inertial Odometry
I'm trying to use the VINS-Fusion package to obtain odometry for a quadcopter. The primary sensor is an Intel Realsense D435i. I've calibrated the camera and IMU extrinsics using Kalibr. IMU ...
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Why are Euler angles used for drones
I know this question is asked before, but the reason why was still not clear to me.
If you've a 6-DOF IMU, the gyroscope measures is degrees/s or radian/s.
Why do we want to convert the body rates to ...
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How to calculate manned drone Thrust, Propeller size and Battery capacity(including weight)
This is for a manned drone with 250 gross weight(academic project). I have assumed the weight of the passenger to be 80kg which is included in the aforementioned value.
The design considered is of ...
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Alternatives to Mount the Motors on Quadcopter
We are doing a quadcopter project and we are at the stage of building the vehicle. However due to lack of attention, the screw holes of the Brushless Motors (Emax CF2822) we bought do not align with ...
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Can an Xbee transceiver module be used for controlling a stable Quadcopter?
I would like to use an Arduino Nano IOT as a flight controller and connect this to a Xbee transceiver module for control. If the Xbee module was set up so that for each packet transmission it included ...
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Inverse kinematics for 2DOF robotic arm in 3D
i am trying to find the inverse kinematics for quadrotor with 2Dof robotic arm, which has first joint rotation axis perpendicular with second joint. So, for the inverse kinematics i use two equations
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Is ADS-B receiver used in PixhawkCube ADS-B out or ADS-B In?
The new carrier boards for Pixhawk Cube seems to be using a 1090MHz ADS-B receiver from uAvionix. This receives location information from nearby aircraft (airplanes, gliders, helicopters, etc.), but ...
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Is VIO a good solution for autonomous drone navigation at higher altiutues (200+ms)?
When it comes in indoor scenarios, VIOs may provide good performance, but when it comes to outdoor environments and high altitudes without proper GPS coverage/stability, are current VIOs capable of ...
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Simulate Wind in Gazebo - physics_msgs
I am trying to simulate a drone inside an environment with constant wind. I have found a good plugin (link below) and I have done the following to integrate this plugin in my system:
include the ...
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Trajectory optimal for quadcopter
I have defined a quadcopter that I control with a PID controller. The dynamics that define it are such.
$T=mg+m\ddot{z}$
$\theta=\frac{\ddot{x}}{-9.82}$
$\phi=\frac{\ddot{y}}{9.82}$
As you can see I ...
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How do I find the transfer function for my quadcopter altitude system?
This is not so much of a how but if I am right so far. I am looking at the z-axis now only. The linearized equation of motion for the thrust in the z-direction is:
$$
T=m\cdot \ddot{z}+mg,
$$
where $m$...
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Air Resistance Drag Force Calculation For Quadcopter
Hello there. Hope you are all doing well.
I have created a dynamic quadcopter model on Simulink and designed a controller for it. So far, everything is going well. However, since I am going to be ...
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Mapping Joystick Inputs to Quadcopter
hope you are all doing well.
We are doing a project where a quadcopter is controlled by an ordinary joystick. We have constructed the Control Algorithm and the joystick to move the quadcopter in ...
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Why does the quadcopter become unstable after turning?
I'm trying to write a simple test MAVROS node where my quadrotor is expected to go in a straight line and then have 180-degree turn and come back and land on where ...
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Can someone explain this yaw angle calculation equation?
Nowdays, I am trying to understand PX4 Autopilot(Drone Flight Control Open Source) attitude control code. But I can’t understand formula below which is in attitude control code description.
Can anyone ...
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Drone Development using ROS Noetic on Ubuntu 20.04
I installed ROS Noetic on Ubuntu Mate 20.04 in my Raspberry Pi but couldn't find any specific tutorial to follow along for Noetic. Most are available for Melodic, which doesn't work with the latest ...
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What devices can I use as a flight controller in a Quadcopter project? [closed]
I know that the flight controller is the heart of the quadcopter and a device which has to be considered greatly when building a quadcopter project. In regards to this quadcopter project that I'm ...
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Drone lost traj recovery
So I am using slam algorithm to localize the drone which is gps denied . The input to the slam algo is imu data and a video .
Now after the first run of the slam algorithm it creates the trajectory ...
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Quadrotor Smooth Trajectory optimization
I'm currently following a course on coursera on quadrotors, and i'm currently focusing on the trajectory planning mechanism.
In the course, it's said that one of the criterias when planning a ...
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Inertial frame's angular velocity expression
I'm following a robotics course on coursera which talks about aerial robotics and more specifically quadrotors.
I'm trying to understand the logic behind the relationship between the angular velocity ...
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Inertial frame VS Body-fixed frame momentum correction factor
I've recently enrolled in a Coursera aerial robotics course and i'm trying to understand how the rate of change of the angular momentum is computed from the inertia frame to the body-fixed frame.
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Quadrotor dynamics: How is torque created
I'm a software engineer and I've recently engaged into Robotics field. I've started by a course on Coursera which talks about Aerial robotics and thus quad-rotors. I'm trying to understand how quad-...
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When is the Quadcopter out of the control?
Assuming ideal environment/hardware flying conditions, is it possible that the autopilot loses the control of the quadcopter?
What is the maximum tilt in roll and pitch that is allowed for the ...
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Quadcopter descends when rolled or pitched
I'm currently working on a quadcopter using f450 frame and YMF32 code. I was able to successfully build the quadcopter and It flies without having any vibrations or wobbles. Also, I tuned the PID ...
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Generate a Trajectory from GPS coordinates
How would I generate a trajectory (e.g. minimum snap/jerk/acceleration) for a quad rotor between GPS coordinates? In all the examples that I have seen, they assume that the x,y positions are in meters ...
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How to make a quadcopter hover when tilted forward or backward?
is making a quadcopter hover forwards or backwards possible ? The only two ways I can think of making this happen is by using motors to move the rotors in such a way that they are always vertical and ...
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Quadcopter PID Controller for distance
I am trying to use a PID controller to stop a quadcopter at a specific location while travelling horizontally, however currently it overshoots/undershoots depending on the max velocity. I have tried ...
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Imaginary part in result of inverse laplace transform
I am working with a system(closed-loop feedback control) that has a transfer function like this
F = 20*(s+5)/(s^4+13.5s^3+41s^2+80*s+100)
this one is in the s-domain but for the response analysis, I ...
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What flight firmware stack is most common in aerial robotics research environments?
I'm considering Aero-Astro grad school and am looking into acquiring a drone hardware platform to implement GNC/ PNT/ autonomy papers like those I might see from, e.g., the Navigation and Autonomous ...
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Barometer altitude calculation
I want to calculate altitude using a barometer which is mounted in the proximity of a number of components which get quite hot and raise the localised temperature. The barometric pressure equation is ...
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Detection of linear acceleration vs rotational velocity/acceleration
I am wondering, how do you differentiate between linear acceleration and rotational velocity and acceleration for IMU? A rotational velocity or acceleration will still appear to the accelerometer as a ...
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For a quadcopter do i need to place the gyroscope sensor at the center of mass?
I am trying to build a quadcopter and think it is essential to have its center of mass in the middle. Therefore, I am planning on putting the battery in the center. However, this will cause me to ...
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BLDC Stuttering when attached to Arduino Nano
I am working on building a quadcopter with an Arduino nano. I am currently only working with 2 motors. However, I am experiencing an odd issue. When I try to run my motors, one of them runs fine, ...
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How to calculate the pitch of the quadcopter rotor blade and their efficiency?
I have gone to some of the blade designs and profiles of the blade which suits my requirement. But, once after entering the Theoretical calculation, I was stuck in the determination or the ...
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Setting up rewards to account for UAV crashes (Reinforcement Learning)
I am working on a project to implement a collision avoidance algorithm on a real UAV. I'm interested in understanding the process to set up a negative reward to account for scenarios wherein there is ...
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Measurements of IMU (accelerometer and gyroscope) are drifted or with too much error
I placed my drone on a table (i.e, at rest) and save (using a ROS topic) the IMU readings:
As you can see, there's a lot of drift or error. I would expect the $x$ and $y$ acceleration to be 0 (I know ...
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What is a low level controller for a quadrotor?
I am studying control systems, and I was reading a paper about quadrotors. In the paper it is said that in the platform of the robot it has to be present a low level controller.
But what is a low ...
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Numeric integration problem in a quadrotor vertical descend code
I'm trying to implement a drone in vertical descend. As for maximum simplification, I maintain all its angles to 0, and just try to get to the my desired descend. However, when I debug, I see that my ...
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Tuning a cascaded attitude and attitude rate PID controller
Assume that I have an object in 3D, and I want to have a controller that stabilizes its orientation (also referred to as "attitude").
To be sure we are clear:
attitude is measured in "degrees" or "...
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Proper Joystick Inputs for UAV Quadrotor Control
I am working on the adaptive control of quadrotor UAV in MATLAB/Simulink environment. I prepared some trajectories for the UAV to follow in $x$, $y$ and $z$ directions. I would like to implement these ...
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What happens when I send the land command to my quadcopter?
My first question is: imagine I have a self-made quadcopter and I want it to land. How can I achieve that? Do I have to stop the 4 motors at the same time?
Second question: I use an AR.Drone 2.0. ...
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what kind of processing is required on raw IMU data before it is fed into a filter?
Im working on quadcopter. At this stage im coding a reference system for quadcopter using 10DOF board.At this stage im at the point of only getting raw data values from accelerometer, gyroscope, & ...
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Solving for rotation matrix: Aligning vector a with vector b and then rotating around vector b
Currently working on a quadcopter simulation. I have a desired thrust vector,
t =sin(30)cos(45)a1+sin(30)sin(45)a2+cos(30)a3
and desired yaw angle,
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Roll, pitch and yaw in a quadcopter
The axis definition affect the roll, pitch and yaw definition in a quadcopter?
Image I have the axis defined this way:
then to roll I have to put a higher velocity in (1) than in (3) (turn around ...
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