All 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 ...
0
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1answer
6 views

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:...
1
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1answer
9 views

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 ...
1
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1answer
14 views

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 ...
2
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1answer
21 views

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 ...
2
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0answers
8 views

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 ...
0
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1answer
12 views

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 ...
1
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0answers
16 views

Question about Lens distortion

Suppose I have a 240x180 camera with the following distortion co-efficients, $$k_1 = -0.138592767408$$ $$k_2=0.0933736664192$$ $$k_3=0.0$$ $$p_1=k_4=-0.000335586987532$$ $$p_2=k_5=0.000173720158228$$ ...
1
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0answers
17 views

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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0answers
8 views

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 ...
1
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2answers
31 views

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", ...
1
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0answers
17 views

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 ...
2
votes
1answer
21 views

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 ...
0
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2answers
11 views

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 ...
0
votes
1answer
24 views

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 ...
0
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2answers
48 views

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 ...
0
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1answer
27 views

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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0answers
9 views

Building a quad-copter to carry 1kg pay load [closed]

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 ...
-1
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0answers
12 views

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.
-1
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0answers
11 views

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. ...
-1
votes
1answer
15 views

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 ...
2
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0answers
14 views

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 ...
0
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0answers
28 views

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 ...
-1
votes
1answer
15 views

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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0answers
22 views

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 ...
0
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0answers
10 views

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 ...
0
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0answers
9 views

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.
3
votes
0answers
16 views

Deriving the equations of motion for free-floating spacecraft with a single link robot arm

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 ...
0
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0answers
9 views

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 ...
2
votes
0answers
26 views

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 ...
2
votes
3answers
36 views

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 ...
0
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2answers
39 views

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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0answers
15 views

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 ...
0
votes
1answer
19 views

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 ...
2
votes
0answers
27 views

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 ...
1
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0answers
16 views

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 ...
0
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0answers
10 views

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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0answers
22 views

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 ...
0
votes
1answer
19 views

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&...
1
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0answers
13 views

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 ...
2
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3answers
44 views

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 ...
1
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0answers
39 views
+50

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 ...
1
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1answer
49 views

Get Yaw from quaternion

I found a formula online to extract yaw from a quaternion like so: ...
0
votes
1answer
50 views

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 ...
5
votes
2answers
62 views

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 ...
0
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1answer
28 views

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 ...
1
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1answer
22 views

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 ...
1
vote
1answer
18 views

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. ...
0
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0answers
15 views

Hover control for quadcopter doubt?

For my project I need to make a hover control using state space approach for a quadcopter. So far I have taken a non linear state space model from a research paper that used 12 states, 4 inputs and ...
1
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1answer
13 views

DJI E310 Thrust Coefficient

I am reading Denis M. Filatov et al.'s paper "Parameters identification of thrust generation subsystem for small unmanned aerial vehicles" (https://www.semanticscholar.org/paper/Parameters-...

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