Robotics Stack Exchange
Robotics Stack Exchange

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1500 questions
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Native ROS vs ROS compatible via API

I am looking to buy a cobot for a research project (budget about 20k€). I happened to see some cobots (e.g. Mara) that claim running ROS natively, some others (e.g. Aubo i5) that is compatible with ROS via API. Since I am not a programmer, could…
drSlump
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building a grid map from gps trajectory poses

I am trying to create a feature grid map with Images from camera mounted to the top of the car. Novatel ProPak RTK gps poses Beforehand, I've checked to ensure that the standard deviations of the latitude/longitude (>5cm) and heading (<0.5…
user23354
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How to render a robotic arm in Unity?

As part of a research project, I'm creating synthetic data, using the Unity engine. I have the final pose of a robotic arm (6 params: 3 for orientation, 3 for location/position), and also a .ply file for the mesh. Is there any way I can use this…
Ambareesh
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Robot moving sideways in RVIZ ROS

Hi, I have a wheeled-legged robot as you can see in the picture. When I simulate it in ROS-Gazebo it works fine, however at the same time in Rviz it moves sideways instead of forward or backwards. I have no idea why it is behaving like this. Would…
Franky
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question about car-like robot localization based on dead-reckoning

I have a question about car-like robot localization using only dead-reckoning. Given: robot position (at current time step) in the form $\begin{bmatrix}x & y & \theta\end{bmatrix}$ (theta is the heading) steering angle distance traveled between…
Navid
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Why is the Kalman filter a filter and not a control system?

Why is the Kalman filter a filter and not a control system? The Kalman filter is a recursive filter which can be used to estimate the internal state of a linear dynamic system with noise in the signal(s). Isn't that the same as a traditional…
Agent56289
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How is this bicycle model in Robotics Vision & Control derived? And is its equation missing something?

I'm reading Robotics, Vision and Control, on page 108 it has following equations: $$\rho=\sqrt{\Delta^2_x+\Delta^2_y}$$ $$\alpha = \tan^{-1}\frac{\Delta_y}{\Delta_x}-\theta$$ $$\beta = -\theta-\alpha$$ How does it go from the above to the following…
drerD
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Adjusting the PWM frequency and duty cycle to achieve the desired angular velocity in differential drive robots

I am practicing C++ and intro to robotics using a simple differential drive robot and a raspberry pi. Also following along the GA Tech course on control of mobile robotics. The implementation I am trying firstly is the Proportional part of a PID…
Sam Hammamy
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quadcopter parameters calculations for simulink model

I want to make a mathematical model of quadcopter in simulink. I have studied quadcopter, although I am new and not build any flying robot before. I studied so far that I have to use four brushless DC motors PID speed control, two motors will rotate…
Abdul Rehman
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How to limit large acceleration and jerk from PID controller?

I am trying to control a robotic arm with force input. The output of the force sensor is filtered, and fed through a PID controller to command the end-effector velocity. However, the robotic arm has strict limits for maximum acceleration and jerk.…
Ove Baardsgaard
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Likelihood Field Matching

I have LIDAR data of an environment in my hand and I want to apply likelihood field matching to this data. I found a source. But I don't understand what the variables of the algorithm mean and how it works. Can you help with that? Note : We're…
umuryasinalper
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5 answers

Is it correct to think of forward kinematics as merely a 'check' for the inverse kinematics?

When the only inputs to your robot are the next x,y,z coordinates of the next point on and on, I can simply just calculate IK to find the angles and make my actuators move to these angles. Whats the point in calculating forward kinematics in this…
mechasker
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Is rospython subscriber thread safe?

I'm trying to write a python node, which has one class and two member functions as callback functions. so a TimeSynchronizer and Subscriber in a node. I saw in this link and tested that python subscribers are event-driven model and are in separate…
jlyw1017
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Struggling to understand Jacobian Inverse Kinematics

I'm trying to find a method to control a moveo 5dof arm. My goal is to calculate the right angle to turn for each stepper motor to reach a desired point in real environment. I've spent time looking at the jacobian inverse kinematics, but it really…
Nguyễn Thanh Tùng
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What is an effective distribution of grayscale sensors on robot

I'm working on a robotics project, and I am using grayscale sensors to automatically follow a black line: turning 90 degrees, going round in a circle, and passing through gaps in the lines etc. I was wondering what is an effective way to detect the…
C_Beginner_Learner
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