Robotics Stack Exchange
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1500 questions
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3 answers

What are these mechanical parts attached to robot arm structures, seen on larger robots?

Between the shoulder and elbow pitch joints, I see two types of connecting structures on larger robots. I've attached a picture. My questions: 1) What are each of the respective mechanical parts called? 2) What is their purpose for the robot…
JDS
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Numpy alternatives for linear algebra and kinematics in python?

Are there any decent python numerical package libraries besides numpy for python? Numpy relies on gfortan which itself must be compiled correctly for your platform to avoid hidden/insidious numerical errors in numpy. I need a matrix algebra package…
hobs
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Rotation matrix sign convention confusion.

In rotation matrix, Why do we rotate the first and third rotation in the opposite direction of the 2nd rotation, this is confusing. Image is attached with this. In this image we can note that for x and Z rotation non zero elements are same. But…
Naseeb Gill
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7
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1 answer

Are there any advantages to using a LIDAR for SLAM vs a standard RGB camera?

I've been thinking about building a small UAV with an onboard LIDAR, just for fun. I'm interested in SLAM and autonomous flight indoors and thought that I would need a lidar to get a 3D map of the environment. Now, I've spent some more time looking…
user12985
7
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2 answers

Reward Function for q learning on a robot

I have 2 wheeled differential drive robot which I use pid for low level control to follow line. I implemented q learning which uses samples for 16 iterations then uses them to decide the best position to be on the line so car takes the turn from…
Ege Keyvan
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Difference between SLAM and "3D reconstruction"?

I'm reading this paper: http://arxiv.org/abs/1310.2053 (The role of RGB-D benchmark datasets: an overview) and see the following words: Thanks to accurate depth data, currently published papers could present a broad range of RGB-D setups…
zhangxaochen
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Path planning for visual servoing

I am at moment trying to implement a visual servoing application. the robot I am using is a UR5, and TCP has a stereo camera mounted on to it. The idea is to move the end effector according to the object being tracked. The path-planning algorithm…
James potter
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6 answers

How to check for a sharp angle with a line follower?

I have the mBot robot and I want to program it to follow the line. So far it can pass any kind of line that is >90°. I want it to be able to pass 90°-ish angles as well. Like this one: The problem is that my mBot robot has only 2 line following…
jan
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Generate transformation matrices for rotating around a object?

How do i compute all transformation matrices which places a robot endeffector at the shell of this sphere, with the end effector pointing toward the object in the center. I know at all time how far the object is relative to the endeffector, and…
test
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Simulated kinect rotation around X [gazebo bug?]

I asked this question on answers.ros.org and gazebo.ros.org but still haven't got any answer. I'm posting my question here with the hope someone can help me. In our robot, the Kinect can be mounted on the side of the arm, as shown in the screenshot…
Ugo
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Controlling more than 12 Servos with the Arduino Servo library

I'm using Teensy hardware specifically. I have a Teensy 2.0 and a Teensy 3.0, and from the documentation it seems like there are two 16 bit timers available, and each should be able to control 12 servos. However, I've attached a logic analyzer and…
Ian McMahon
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3 answers

Use data from gyroscope to calculate orientation

From a gyroscope I'm getting angular velocities [dRoll, dPitch and dYaw] as rad/s, sampled at intervals dt = 10ms. How do I calculate the short term global orientation (drift ignored) of the gyroscope? Pseudo code would be helpful.
Lars
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How do I design for a target speed?

I need to make an omni wheeled robot platform (4 wheels), which should go at a minimum speed of 15 cm/s. I have an idea for the design, but since this is my first time doing something like this I have made a lot of assumptions. I decided to choose…
capcom
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6
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Quadcopter PID Control: Is it possible to stabilize a quadcopter considering only angle measurements?

Good day, I am a student currently working on an autonomous quadcopter project, specifically the stabilization part as of now. I am using a tuned propeller system and I also already considered the balancing of the quadcopter during component…
user123456098
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Mechanical design for motorized spherical caster wheels

Design goal is to have a mobile robot that operates on 3 large casters, essentially 2 to 4 inch diameter steel ball bearings, that are motorized. No other mechanism would touch the surface. The robot should thus be able to move in any XY direction…
Anindo Ghosh
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