# All Questions

19 views

### How should I understand sequential importance resampling in a particle filter?

Suppose I implement a particle filter with $n$ particles. This is a brief description of my understanding of a particle filter. For the first step, I throw out $n$ particles some distance from my ...
20 views

### Why using screws instead of homogeneous transforms in kinematics and dynamics?

Can anyone give a justification for using screws (twists, wrenches) instead of the traditional approach (rotation matrices, homogeneous transforms)? Even if screws are more compact, the situation gets ...
27 views

### Meaning of a negative step response with quaternion

It's not technically robotics but: I've been trying to reproduce in Simulink a spacecraft attitude simulation using quaternions, and the kinematics and dynamics seem to work fine, however I'm having ...
21 views

### How to calculate screw axes relative to end effector [on hold]

Background: I was reading this book called 'Modern Robotics: Mechanics Planning and Control' -by Kevin M. Lynch and Frank C. Park In the section 4.1.2 'Screw Axes in the End-Effector Frame' they talk ...
19 views

### Robot localization using sensor fusion (How to model the Extended Kalman Filter)?

I am new to the robotics field and sensor fusion as well. I am trying to localize my robot using the data from my camera and the odometery through extended Kalman filter. I have the data offline, I ...
7 views

### Choosing battery for quadcopter with optimal capacity [on hold]

let say my quadcopter is weighing 1kg and I'm using a 1000kv motor with 30A ESC then which battery and with what capacity do I prefer for a good flight time
28 views

### How to reduce costs in AI research? [on hold]

Some philosopher have argued, that it is unknown what Artificial Intelligence is and that we first watch ants, to understand their collaborative behavior. And then, we can build intelligent machines. ...
21 views

### Controlling industrial grade dc motors fitted with analogue or digital encoders for robotic arm

I am new to such industrial motors. I searched through the datasheets of these motors ( analogue and digital ) and didn't get clear answer about how I would be able control with MCU like Arduino or ...
21 views

### provide world map for ekf global localization problem

I am trying to implement the ekf_localization algorithm in page 217 (Table 7.3) of the probabilistic robotics book by Thrun. From my previous post, I understand that I need to extract observed ...
12 views

### Looking fo the electronics to control a gyro wheel [closed]

Looking for an open source code and electronics To control a gyro wheel like in this link please https://youtu.be/bI06lujiD7E
19 views

### stable altitude quadcopter

I'm currently working on a project to generate a stable altitude and automatic control for a quadcopter I'm using arduino as the flight controller Ultrasonic sensor HC-SR04 MPU-6050 However my ...
30 views

### Quad-rotor 1-D Linear Control Simulation with MATLAB

I was Performing Programming Assignment with MATLAB for Quad Thrust and Height for an Introductory Course. The control input for a PD controller was According to the Equation u = mass*(diff(s_des, 2)...
41 views

### EKF localization data association

I am working with ROS indigo and clearpath huskyA200 and wanted to implement the EKF localization with unknown correspondences with my own hokuyo lidar data for a school project. Giving the algorithm ...
19 views

### Whats the purpose for an animatronic? [closed]

Whats the purpose for an animatronic, is an animatronic for entertainment or other purposes like weapons or combat or just anything for a purpose?
7 views

### Bending Moment Doubt [migrated]

https://imgur.com/a/m27Bd7H I don't understand how bending moment is being calculated in the problem mentioned in the above link. I understand the parts after that i.e. calculating elastic potential ...
16 views

### start working on passanger drone [closed]

I need to know the motor and the propeller size to lift 300 kg weight up to 250 feet. Machine radius is around 6 feet in circle. how many motors needed. Thanks Shah
16 views

### What happened to Novint Falcon Haptic device? [closed]

What happened to the resources that were previously available for Novint Falcon, there is no resources or proper information regarding this matter. if anyone knows anything about it, please help me ...
23 views

### Best desktop robot to buy with the best support [closed]

I want to get a desktop robotic arm to learn path planning for robots and I was wondering what the best brand to buy was. Background I was hoping for a version that has a lot of community support so ...
28 views

### Relation between GraphSLAM and Iterative closest Point algorithm

I have lots of doubts about GraphSLAM, The GraphSLAM Algorithm with Applications to Large-Scale Mapping of Urban Structures. When I practically implement it I get matrix singularity error. I taken ...
53 views

### Controlling Stepper or DC motor with L298 or L293 and getting operation similar to Servo for 6 dof arm

I will be using 1:4 gear ratio and thus will require a motor with a continuous 360 motion and a high torque for efficient functioning. Servo motors with continuous rotation and high torque are very ...
44 views

### In practical terms, how close is the accuracy of camera-based visual odometry/SLAM methods to lidar-based methods for autonomous car navigation?

Benedict Evans, a general partner at Andreessen Horowitz, claims that “almost all autonomy” projects are using lidar for SLAM, and that not all of them use HD maps. An MIT group is testing self-...
41 views

### Calibrating Logitic C920 HD 1080p using ros kinetic

I am trying to follow the ROS monocular camera calibration for a USB camera I have, but the calibration routine fails when I try to run it. I was expecting to see an image like the one below, but I ...
13 views

### Is it possible to calculate the gear reduction based on datasheet of SG90?

is it possible to calculate gear reduction based on the datasheet of SG90 servo motor? Because I wanted to do some modeling in Simulink and RC servo ask for gear reduction, but I can't find any ...
172 views

### Denavit-Hartenberg convention in practice

How are the coordinate frames and D-H parameters determined in industry? Does one use the CAD drawing of the arm or physically take measurements of the actual arm?
38 views

### how to implement trapezoidal velocity profile in code

I want to use a trapezoidal velocity profile(cartesian) but I struggle with implementing the equations to code(c++/python). Does anyone have an example for this? UPDATE more details about my problem. ...
24 views

### Finding Joint speeds for each joint of a 6DOF arm (UR10) using the Inverse Jacobian

Background: I have access to a UR-10, 6DOF robotic arm through my school (I'm very new to robotics). I know the desired set of linear speeds that I want in the x,y, z-direction in terms of the end ...
30 views

### GraphSLAM equation doubt

I have question about GraphSLAM implementation. To find out the path and map using GraphSLAM we rely on this equation: $$\mu=\Omega^{-1}\xi$$ where $\Omega$ is our information matrix which ...
36 views

### rosservice via Python

I have a drone which has certain services, say random.srv. I want to use this service via Python. Now I know that there is a page in ROS wiki that tells you how to create a service client in Python. ...
24 views

### Graph Slam Landmark remove and then again add it

I try to implement Graph Slam in real dataset. My data set have some data that describe that the Robot observe same landmark over and over with a large amount of time difference. Prof. Sebastian ...
26 views

### How to detect loop in robot movement observing odometer data

I have some odometer data. This data are based upon robot movement. I can transfer those raw data to a motion equation from where I get x,y,and theta co-ordinate of a Robot. If I plot those x,y ...
7 views

### ESP8266 with DS3231 RTC

I want to use external RTC with ESP8266 to hande alarm more accurately. This lib is overwhelming, there is a lot of unnecessary stuff in examples I think. Is there any simple way to set time and ...
30 views

### How exactly does sensor fusion work in Kalman filters?

I've been looking into implementations of Extended Kalman filters over the past few days and I'm struggling with the concept of "sensor fusion". Take the fusion of a GPS/IMU combination for example, ...
21 views

### measurement model of the accelerometers in IMU

I am new to IMU. About the measurements from IMU, different materials give different explanations. From the link: https://www.it.uu.se/edu/course/homepage/systemid/vt14/tokp2.pdf Here the b maybe ...
15 views

### Using Lidar data to detect distance of nearest obstacle, and rate of change

What's the statistically and mathematically correct way to process lidar data so that I can find out a good current estimate of the closet obstacle and its rate change? Should I be learning about ...
42 views

### How to move a Stepper Motor to a desired angle with raspberry pi?

I will be using stepper motor in 6 DOF robotic arm along with Servo motors. Unlike Servo motor ,I find difficult to control Stepper motor. I was earlier using only Servo Motors but due to lack of ...
47 views

### Multiple View Triangulation method used by COLMAP

I'm looking at how COLMAP does multi-view triangulation. I can't work out what this function is doing. I can't find any formulas which look similar. The input "proj_matricies" come from pose data, the ...
95 views

### Alternative to ROS? [closed]

This might be a tricky question, but having dug in deep with ROS I am noticing the complexity that one has to deal with. Simple Arduino programming is much simpler but of course can’t do many useful ...
25 views

### EKF localization with known correspondences to understand SLAM

I am working with ROS indigo and clearpath huskyA200. I want to implement the EKF localization with known correspondences to understand SLAM better and I’ve been reading probabilistic robotics book by ...
16 views

### Fixing robot orientation using AR

I am creating a project where a robot needs to face a control panel and do some specific tasks. Some reference tags will be placed on the panel. I want to use the tags as AR reference and fix my ...
10 views

### Can a mu-metal enclosed compass measure the earth's field?

I am thinking about using a combination of mu-metal, a faraday cage, and spacial separation to reduce magnetic interference from a brushless motor on a compass sensor. The compass will be used to ...
17 views

### How can I limit the current sent to my 6V servos to ensure they don't burn out?

I'm using an adjustable desktop power supply (0-30 volt DC, 0-10 amp) to power my robot which has 7 standard 6-volt servos. There are some situations where the robot gets jammed, and power draw ...
55 views

### Data saving/sharing standards for objects, actions and senses

I am working on a language (computer language) for robotics to communicate with each other. I am looking for naming standards that is unique and usable for robotics, for example when two robots are ...
44 views

### What I need to learn to build drone to monitor climate changes [closed]

Based on this answer to a question about what to learn to create a robot: I am a telecommunications engineer with a knowldge in different programming languages and electrical/electronic circuits ...
29 views

### Practicality of using magnetometer inside AUV

I have an AUV with a 12 inch diameter, 29 inch long capsule. Inside the capsule sits an Intel NUC computer, an NVIDIA Jetson GPU, an Arduino Mega, a Sparton IMU (9 DOF) as well as a custom voltage ...
50 views

### Are there standard angular velocities when it comes to robotic arms?

for manipulators that lift heavy loads, e.g. a car or a cow, what would be the ideal angular velocity? Are there any standards for arm safe moving speed? (of course I know it depends on the project ...
28 views

### How to avoid matrix singularity in GraphSLAM

I am trying to implement GraphSLAM from Sebastian Thrun's paper, The GraphSLAM Algorithm with Applications to Large-Scale Mapping of Urban Structures. When I compute the inverse of my information ...
22 views

### Why does the low variance resampling algorithm for particle filters work?

I am studying and coding particle filters and I am using the Low variance sampling algorithm suggested in the Probabilistic Robotics book. I understand the procedure for the algorithm. A random number ...
47 views

### What propeller to use for in-pipeline robot?

Currently im working on an in-pipeline inspection robot that can navigate through narrow pipeline. My design is to use a propeller at the back to push the robot forward. The front part of the robot ...