Robotics Stack Exchange
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1500 questions
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2 answers

Whats the logic to implement a particle filter for a robot with range sensor?

I am trying to implement a particle filter for a robot in Java. This robot is having a range sensor. The world has 6 obstacles - 3 in the top and 3 in bottom. I am calculating the distance of the robot from each obstacle's center and then performing…
Ambidextrous
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DC motor control - speed-torque curve

I am having some trouble understanding how to practically use the speed-torque curve of a DC motor. I understand that the gradient of the speed-torque curve is defined by the design of the motor, the exact position of the curve depending on the…
arennuit
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Quadcopter: Stabilization along the z-axis (for holding altitude)

I recently spent some work on my quadcopter firmware. The model is stabilizing its attitude relatively well now. However I noticed, that it is changing its altitude sometimes (maybe pressure changes, wind or turbulence). Now I want to get rid of…
dgrat
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How do I model a robot?

The answers I received to the question on training a line following robot using reinforcement learning techniques, got me to think on how to train a robot. I believe there are essentially two ways - Train the physical robot. Model the robot and…
Lord Loh.
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Visual Odometry options?

What are the pros/cons of the different visual odometry options? Stereo Camera Optical Flow SLAM other? Criteria: how well it performs vs other odometry options/sensors (lidar, radar) sensor fidelity computation accuracy precision drift native…
eruditass
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What kind of performance can I expect when using an Extended Kalman Filter for calibration and localization?

Currently I have a tricycle style robot that uses an extended kalman filter in order to track 6 state variables. The inputs to the system are a steer encoder, a distance encoder, and a rotating laser that returns bearing only information to known…
ApockofFork
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Denavit-Hartenberg convention

There are two different conventions that can determine DH parameters. What is the difference between Craig's [1, Sec 3.4] convention and the Spong [2, Sec. 3.2] convention? I know that both methods must have the same response. [1]: Craig, John J.…
Parham sagharichi ha
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Which spline function would be best suited for the trajectory of a differential drive

What's the best kind of spline that can be used for generating trajectory that can be adapted during execution time? The use case is having a differential drive which has to move towards a point (x,y,theta) without stopping during the movement (e.g.…
Maverik
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innovation step ekf localization?

Let's say we have a bunch of observations $z^{i}$ from sensor and we have a map in which we can get the predicted measurements $\hat{z}^{i}$ for landmarks. In EKF localization in correction step, should we compare each observation $z^{i}$ with the…
CroCo
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Accelerometer, gyro, and magnetometer sensor fusion in 2d

I have not yet built this so this is basically a theoretical question. I am still wrestling with some C code to manage i2c communication etc. When I originally said "I have not built this", I meant that the robot is in what could be called a "design…
tired_of_nitpickers
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Is there an analytical solution for inverse kinematics of a 6 DOF serial chain?

Let's take a 6 DOF robotic structure. It's consisting of the 3 DOF global structure for the position - and the 3 DOF local structure for the orientation of the endeffector. If the last 3 axis (of the local structure) are coincident in one point, the…
Hummingbird
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Multiple position estimates fusion

I have a system in which I have two separate subsystems for estimating robot positions. First subsystem is composed of 3 cameras which are used for detecting markers the robot is carrying and which outputs 3 estimates of the robot's position and…
Damjan Dakic
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Quadcopter forward speed

I am trying to better understand the dynamics of forward flight in multirotors. Assuming I have a quadcopter with 4 motor/propeller combinations capable (each) of a propeller pitch speed of, say, SpeedMax= 100 mph. In forward horizontal flight, the…
user4128
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What is the best way to fuse measurements from IMU, LIDAR, and Encoder information in some recursive bayesian filter?

I am doing SLAM with a four wheeled (2-wheel drive) differential drive robot driving through some hall way. The hallway is not flat everywhere. And the robot turns by spinning in place, then traveling in the resulting direction. The SLAM algorithm…
chibro2
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Are propellers dangerous?

Aren't all propellers super dangerous? How are these startups like Hex and Pocket Drone selling drones as 'kid-friendly' to consumers? What happens if a kid puts his finger in a propeller's movement space while its flying?
dude
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