# All Questions

4,332 questions
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### Robotic Arm Senior Capstone. Electronics/Controls/Sensors Questions

I am a mechanical engineering student currently working on my senior capstone. My team of all MechEs has to build a robotic "arm" where the arm is really just a link/bar of aluminum. The thing we ...
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### Stay both pointed forward and equal distance from side walls

Simple task, robot with total knowledge about the world or at least a few side mounted IR sensors which can accurately measure where the robot is relative to a long straight corridor. We want to BOTH:...
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### the biases in the state vector of extended kalman filter(EKF)

I am reading one paper on observability Observability Analysis of Aided INS with Heterogeneous Features of Points, Lines and Planes. The state vector contains the current IMU state and the feature ...
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### How to implement Kalman to merge the data obtained by two Leap Motion devices?

Only position data is obtained from Leap Motion devices. This data was already processed to be on the same coordinate axis by means of a homogeneous transformation. I'm reviewing WTF is Sensor ...
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### 2D Transformations as Affine Matrices

I have found the following exercises about 2D Transformations as Affine Matrices. I am stuck at the second exercise that goes as follows: The 2D pose of a robot w.r.t. a global coordinate frame is ...
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### Making a robot go in a straight rate - sampling rate for motor PID

I'm trying to build a robot/rover based on Raspberry Pi 3 At the moment I'm straggling with a basic driving in a straight line. I'm in a process of tuning my PID code andI'm not sure what sampling ...
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### IMU and Camera Synchronization

I would like to synchronize my IMU and Camera sensors for my real-time visual-inertial SLAM algorithm in ROS. I am streaming video at 30 Hz from an android phone through IP address. IMU, however, has ...
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Suppose I have a 240x180 camera with the following distortion co-efficients, $$k_1 = -0.138592767408$$ $$k_2=0.0933736664192$$ $$k_3=0.0$$ $$p_1=k_4=-0.000335586987532$$ $$p_2=k_5=0.000173720158228$$ ...
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### Roboclaw 2x15A Motor Controller giving a Driver Fault error

I'm trying to get a Roboclaw 2x15A Motor Controller working, I'm trying to control 2 NeveRest 60 Gear Motor for differential drive. I installed the software, connected a battery, and USB cable. I'm ...
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### How do I reinstall the SDK on a Baxter robot?

I need to replace the SDK on my Baxter in order to resolve an error (details here: Baxter's ready status is 'false', won't enable) However, I can't find any information on google ...
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### Inverse Kinematics - How to only find a unique joint angle solution in 4 dof robot?

I have to develop an algorithm to determine the necessary joint angles to achieve a desired TCP position and orientation in a 4 joint manipulator. I have come across a concept called "degeneracies", ...
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### Kalman filter with measurements indirectly determining state

I have a question regarding a 'fundamental' understanding of the Kalman filter. So, for my application I'm trying to estimate state $x = [\theta~\dot{\theta}~\ddot{\theta}]$ of a robot based on ...
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### Using pre multiply or post multipy for rotational matrix to get a new homogenous transformation matrix?

I am confused about how do I multiply the rotational matrix in this case. I know that both T1 and T2 needs to be multiplied by a rotational matrix but I don't know how to multiply the rotational ...
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### Why Euler Angle is set to be in ZYZ order?

We have 3 DOF for rotation in 3D space. So to describe an arbitrary rotation, we need to describe its 3 DOF. Euler angle does this by dividing a rotation in 3 steps, first rotate along the Z axis of ...
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### Practically implementing a torque controller

I'm currently working on a robotics project where i have to build a quadruped. i have somewhat finished the designing for the time being and now moving into simulations. I have followed a inverse ...
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### Setting Reference-position for axis

The problem is that our robot (a demolition robot named brokk170) does not have any built-in sensors which can provide the position of the axis. We thought of attaching markers on each axis to have ...
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### Help in Computing Inverse Kinematics of a 5 DOF Robot Config

Its is a robot config with 5 DOF. We are provided 2 offsets d1 and d2. d1 and d2 are both 0.04 meter. It is confusing for me alittle bit. I am attending lectures online but I am having trouble ...
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Sir/Madam, I'm from India. Making a drone is a growing hobby here but the technical resources are very limited. Would you like to help to choose a motor and ESC for my quad-copter with 1kg extra ...
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### which are the most powerful components in rebot and which one language mostly used in rebotics? [closed]

which are the most powerful components in rebot and which one language mostly used in rebotics? And which component is utilize first in rebot.
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### Given the directions and distances the robot traveled, how to generate a plot against a grid layout in a rather smoothed manner? [closed]

I've got the robot's travel segments and intend to visualize it against the backdrop of grid layout. These travel segments are determined as function of wheel rotational difference between two wheels. ...
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### RF-transceiver for real-time video streaming?

I'm working on an RC-controlled model aircraft. One of the features I'd like to implement is real-time video streaming from the drone's camera. Distance is going to be a few dozen, or better hundred ...
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### Wheeled Mobile Robot State Estimation Model Using Odometry

I have a process model update that follows the form: $$\mathbf{x}_{k|k-1} = \mathbf{x}_{k-1|k-1} + \delta \mathbf{x}_k,$$ where $\mathbf{x}_{k-1|k-1}$ is the posterior estimate from the last ...
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### What servo motors do I need for lifting at least 10 pound of something and hold it in place? [closed]

I am very much new to robot building. I am building a robotic arm for a everyday use. Basically, it will be used to hold and position a yard tools while the tool is being used and will be controlled ...
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### what specification required for quardcopter to pickup 5kg weight

For a college student project, I am designing a quadcopter with a payload of 3-4kg. As I am new I don't know what are the implications of such a requirement on the quadcopter design. In particular ...
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### How to use the sensor data(Dead reckoning, odometer) to keep track of multiple robots and their movements?

Objective: The goal is to present to the management the real time tracking of the cars and the loader activities; and to eventually aid the communication of their performance for better management of ...
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### Let a iRobot Roomba run without cleaning

We've got an iRobot Roomba and since about a week, we also have a dog living with us. Today we tried to let the Roomba clean for the first time, which made the dog go absolutely nuts. Is there a way ...
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### Using py_trees for real robot

is anybody using py_trees for a real robot or with gazebo simulation ? I'm interested in some real ROS project experience. Does py_trees perform or is it to slow for robot control.
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Note: I had previously posted this question on the Space SE site, but received little/no response. So I've deleted the old post and repasted it here in the hope of getting more responses. I'm trying ...
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### Best practice for robot control in gazebo-ros project

I would like to design some control algorithm for a mobile robot in ROS and simulate it with Gazebo. The goal is to develop such structure of the project to be able to switch the control mechanism ...
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### Multivariable PID controller

I'm making a robot that uses two DC motors to move, and has two distance sensors on its right side. I want to make a PID controller to control the angle of the robot (using a wall as reference) and ...
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### Polylactic acid - Can I drill into it?

For a school project, I'm creating a mechanical arm and I'm thinking about using a 3D printer to create some of the pieces. Obviously, This arm is dynamic, so I wanted to make the pieces as light as ...
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### Indoor GPS 3D for navigation

I'm looking Indoor GPS system for agriculture tasks in a greenhouse. I want to make an autonomous robot who can navigate by "GPS", I want the system to be 3D (x,y,z) and allowing the I can use robotic ...
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### does anyone are familiar with ardrone's IMU?

I would like to present a visual-inertial navigation system based on ardrone2.0, so I need to calibrate jointly the forward-looking camera and the inertial measurement units. unfortunately, I don't ...
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### How to maintain a robot's center of gravity

I am on a robotics team where our robot has to balance on an unstable beam. However, at the same time, the robot must be able to reach to the side in order to grab field materials. What possible ...
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### OpenRAVE “fast-forward” physics simulation?

I am working with OpenRAVE simulator and I am using ODE Physics (OpenRAVE plugin to support ODE). I have a robot in an environment and multiple other objects that are subject to the physics engine. I ...
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### Accuracy of monocular visual-inertial odometry

I am currently considering to use monocular visual-inertial odometry to localize a smartphone relative to a known object. Now, what I would like to understand, is what kind of accuracy I can expect ...
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### ROS - Use Ubuntu Xenial Packages on Raspbian

I've got a Turtlebot3 and installed Raspbian Stretch on the Raspbery Pi, which is on the robot. For that I used the preconfigured image and the tutorial from Robotis. I followed the tutorial and got ...
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### Driving the iRobot Create 2 straight

I am attempting to make the iRobot Create 2 drive in a straight line using the opcode 137 with the parameters specified in the OI documentation. "Straight = 32768 or 32767 = 0x8000 or 0x7FFF" I have ...
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### 18 MG996R servo motors control and power

I am currently working an a personal hexapod robot project. I am building it using 18 MG996R 4.8 to 7.2 V servo motors. I would like to use a Raspberry Pi 3 B+ to control it. I purchased a 7.4&...
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### Understanding the kinetic energy expressions for a 1 link vs 2 link robot arm

I'm studying these lecture notes on dynamic models of robot arm links, slides 33-36, where two examples are given for the kinetic energies for a single link and two link robot arm. In the single ...
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### Benfit of behaviors & benefit of hybrid systems

I have two questions that I think are closely related: Why is it useful to introduce behaviors, e.g., goal-to-goal + obstacle avoidance? (The alternative would have been to just use a single behavior ...
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### weired actuator position plot

I am trying to design an MPC controller to control the velocity of an actuator. The robot is inside a pipe to inspect the pipe. My input for this system is PWM and output is the velocity of the ...
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### Get Yaw from quaternion

I found a formula online to extract yaw from a quaternion like so: ...
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### What servos are suitable for a robot like Boston Dynamics’ Atlas?

I have seen Boston Dynamics’ robot Atlas do some pretty impressive things, like a backflip, which must put quite large torques on the servomotors. What servos are there that can generate torques like ...
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### 5 DOF robot - Velocity Inverse Kinematics

I am modelling an articulated robot arm with 5 degrees-of-freedom from igus (igus Robolink). I deduced its direct kinematics equations using Denavit-Hartenberg parameters and homogeneous ...
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### Orientation from magnetometer data

I saw lot of topics with the same title but answers are different. I have a magnetometer in my phone which give me the components of magnetic field in direction of X, Y, Z. If my phone lays on a ...
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### What limits the observer eigenvalues size?

IIUC, the recommendation here of increasing the absolute size of the real part of observer eigenvalues is based on two factors: We want the observer to be updated as fast as possible (I suppose up to ...
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### Is it possible for a CC-turn trajectory to not touch the inner circle?

I'm currently struggling with understanding how a continuous-curve path can be constructed in a specific context: A vehicle is supposed to do an 180 degree turn at the end of an agricultural field. ...