All Questions

5
votes
0answers
348 views

How does one implement a third order complementary filter for estimating altitude using data from an accelerometer and a barometer?

I am working with the CJMCU build of cleanflight on a small drone. As of now, the algorithm for altitude hold uses a first order complementary filter to combine data from the barometer and the ...
4
votes
0answers
85 views

Matlab: Simulate received signals of sonar sensors

StackExchange community! I need the guidance what to use for the generation sensor data in Matlab. My purpose is to optimize the exploration process of unknown environment using the multi-robot ...
3
votes
0answers
51 views

Can you find object distance using camera pose

I have bounding boxes detected in RGB images, but no information about the camera's intrinsic properties. Using deep learning (preferably) can I find the distance to the object from the camera in real ...
3
votes
0answers
94 views

Monocular SLAM depth reconstruction

I am trying to derive the inverse depth equation used in monocular SLAM algorithms. Specifically the equation 8 of the ORB SLAM paper I am very close, except I do not understand where the (u_j-c) ...
3
votes
0answers
101 views

LQR for Inverted pendulumn

I'm studying an optimal control for the inverted pendulum in the following figure the state and the output of the system are defined as $$x=\begin{bmatrix}r & \theta & \dot{r} & \dot{\...
3
votes
0answers
293 views

Are there any open source path planning libraries that implement Voronoi diagram techniques?

I've been looking into path planning for a non-holonomic robot with 3 DOF in a 2D plane and recently learned about Voronoi diagrams but I cannot find any open source planning libraries that use this ...
3
votes
0answers
150 views

Geometrical solution to an IK problem for a humanoid robot leg

On the attached figure, I show a graphical representation of the problem I am facing. I have developed a humanoid robot with a thigh which makes an angle with respect to the leg. It means that there ...
3
votes
0answers
111 views

Examples of Zeno Behaviour in the Real World

Zeno Behaviour or Zeno Phenomenon can be informally stated as the behavior of a system making an infinite number of jumps in a finite amount of time. While this is an important Control system problem ...
3
votes
0answers
578 views

ROS MoveIt!, virtual joints, planar joints, prismatic joints

I do have a robotic application, where a 7Dof robot arm is mounted on a omnidirectional mobile platform. My overall goal is to get MoveIt! to calculate a sequence of joint movements, such that the ...
3
votes
0answers
103 views

Maximum ball screw speeds

What is the maximum rotational velocity of miniature ball-screw (diameters up to 12mm) for approximately 1000 thrust cycles, and which type/brand would that be, if the speed is limited by the ball ...
3
votes
0answers
128 views

On-board monocular odometry for quadcopter stabilization

Has anyone done this with EKF/PID on a small microcontroller? Or know of code snippets to help implementing this?
2
votes
0answers
19 views

Stereo Rectification when Extrinsics are known

Suppose I have two cameras $C_1$ and $C_2$ arranged in a stereo configuration. Let us assume that the camera is free of distortion with ideal intrinsics and that the camera extrinsics $R$ and $t$ are ...
2
votes
0answers
40 views

CNC stepper motors are loud and slow after decreasing the steps/mm from 250 to 5

I'm making a drawing robot and have hooked up my steppers to each axis. I'm using the grbl shield with arduino and nema 17 steppers. Initially the firmware was set at 250 steps/mm but with my setup ...
2
votes
0answers
83 views

Magnetometer Calibration

I'm looking at using a magnetometer in a project and I'm struggling to understand the proper procedure for calibration of the sensor. I understand that magnetometers need to be calibrated to ...
2
votes
0answers
11 views

Fiducials in conjuction with AMCL

I'm having some trouble getting fiducials (using aruco_detect) to work alongside amcl. The goal here is to use normal amcl localization when a fiducial is not present, and to switch to localization ...
2
votes
0answers
23 views

Create path with minimum curvature for Ackerman drive

I'm trying to create a trajectory between two given poses for an Ackerman drive. The poses are defined as follows: Current Pose position $(x_0, y_0)$ rotation on z-axis $\theta_0$ Final Pose ...
2
votes
0answers
39 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 ...
2
votes
0answers
37 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 ...
2
votes
0answers
36 views

How rational is it to use Intel Realsense for my affordable indoor autonomous robot?

Right now, I am using ESP32 for the motors and planning to add either Raspberry Pi Zero or ARM Cortex-M4 (STM32) and use ROS with Intel RealSense RGBD camera. How sensible is it? I am not expert in ...
2
votes
0answers
40 views

Strategy for 3D path planning over large distances with kinodynamic constraints

I was hoping to pick your brains about a problem that even after much reading has left me baffled. My Application: For the sake of simulating underwater scenarios in very large environments (up to ...
2
votes
0answers
59 views

Is there a Kinfu version that runs with ROS on an Odroid?

I have a ROS-based robot that runs on an Odroid with a 3d Camera (Openni-based) and would like to use Kinfu (or something similar) on it. I'm not sure if the Mali-GPU is fast enough, but so far I didn'...
2
votes
0answers
73 views

Position-Attitude Kalman filter with Quaternions

I want to design an EKF to estimate the position of a UAV. If I were doing this with Euler angles then I would have a state vector that would look like \begin{bmatrix}north&east&down&...
2
votes
0answers
92 views

How does marginalization of variables effect least squares SLAM energy function?

Consider a simple example of Bundle Adjustment where I have robot and landmark poses $x = \left[ x_p \text{ } x_m\right]^T$ and measurements given by $z$, such that a simple factor graph can be ...
2
votes
0answers
67 views

Multiple antenna styles on FPV without true diversity

I did a search and couldn't find a site that stood out as RC. I was hoping you guys would be closest. Here's my question. I bought a set of Eachine EV100 FPV goggles. Every resource I've looked at ...
2
votes
0answers
73 views

How to properly initialize every new pose in a Visual SLAM algorithm (namely DSO)?

My question is a bit specific, because it is linked to a certain algorithm. Therefore I didn't find any other solutions on how to go about this problem. If you could refer me to research papers, ...
2
votes
0answers
23 views

Torque commands for velocity reference motor

I have a controller board for a motor, where I can read the motor current (to transform to torque), the position, the velocity and I can give a velocity command. There is not really a torque mode on ...
2
votes
0answers
477 views

ROS Gazebo Odometry Issue

I am setting up a Gazebo model for use with the navigation stack. I have been reading the Navigation Tuning Guide and am confused about the lidar data in the odom frame. I would think that the tuning ...
2
votes
0answers
53 views

From a linear force actuator that spans multiple links and joints to the equivalent motor torque

I am programming/using a rigid body joint-space dynamics solver for robots in which I want to implement linear force actuators between links with their equivalent torque sources that are 'spanned' by ...
2
votes
0answers
62 views

VREP - Attaching Baxter manipulators

Trying to add manipulators to the VREP Baxter robot, I can add the gripper easily enough by adding the manipulator object in a scene to the appropriate arm tip and setting its position and rotation to ...
2
votes
0answers
24 views

Robotic vessel navigation using GIS datasets

I am trying to build an autonomous vessel able to plan the best route to a certain waypoint or to follow a pre-defined route. Currently, I have imported Esri GIS files containing elevation data (...
2
votes
0answers
58 views

Effectiveness of visual odometry algorithms (CPU usage)

My robot needs to obtain visual odometry, with a condition that the used algorithm has to have as low computational requirements as possible and the used camera/sensor shouldn't be very expensive. The ...
2
votes
0answers
24 views

Gyroscope modeling parameters

Well im trying to model a gyroscope which is MPU-6050 and i am stuck in getting the missalignment and scale factor parameters from its datasheet ... And there is another problem that the names in ...
2
votes
0answers
158 views

Holonomic constraint forces using Lagrange multipliers

Consider a multibody robotic system with Lagrangian $ L = \dot{q}^{T}M\dot{q} + V $ and equations of motion of the form $$M(q)\ddot{q}+C(q,\dot{q})\dot{q}+A^{T}(q)\lambda+N(q)=0 $$ where $N=\frac{\...
2
votes
0answers
65 views

How do CAD programs solve for Inverse/Forward Kinematics problem in Assembly?

I am trying to solve for the Forward kinematics of a spatial parallel manipulator. Its loop closure (LC) equations are pretty long, and are being solved using numerical methods. As I am adding more ...
2
votes
0answers
66 views

Consitent Scale in Monocular pose estimation

I just wanted to know if scale is conserved across multiple images, when doing a process such as monocular odometry. I know in reality the scale tends to drift over time due to accumulation of small ...
2
votes
0answers
121 views

Simple inertial 2d path planning library for arduino

I have a pretty simple 2d manipulator which uses an arduino to control a payload weighing about 2kg. I want to implement a simple 2d path planner which takes as input: Current position, velocity, ...
2
votes
0answers
352 views

real-time stereo vision system for long range (up to 100m) depth estimation

I want to implement a FPGA-based real-time stereo vision system for long range (up to 100m) depth estimation. Also, I want to use two ip cameras in the system. I have calculated depth error using the ...
2
votes
0answers
197 views

Visual SLAM for wheeled robot

I would appreciate your help for choosing the appropriate real-time SLAM algorithm. I am interested in having autonomous robot, thus a SLAM component is needed for autonomous navigation. The ...
2
votes
0answers
41 views

What is the effect that the size of the correlation window (in pixels) has on the matching performance of stereo algorithms?

While stereo algorithms perform matching, they usually compare pixels within a region around the feature. I would like to know what effect the size of that search window has on the matching ...
2
votes
0answers
143 views

Introducing new particles in particle filters for localization

Standard particle filters can produce bad localization result if the initial particle generation step produces no particle that is close to location (and bearing) of tracked object. The accuracy ...
2
votes
0answers
363 views

How to properly calibrate a magnetometer in IMU for precise yaw?

EDIT: Moved to ElectricalEngineering StackExchange Community I'm using Sparkfun Razor IMU 9DOF sensor which incorporates accelerometer, gyroscope, and magnetometer, for giving the Euler's angles (yaw,...
2
votes
0answers
221 views

Triangulation from calibrated stereo rig

I am using a stereo rig to do SLAM, calibrated using the MATLAB Calibration Tool. I need to compute the 2D coordinates of a landmark using the observation model obtained from triangulation (the images ...
2
votes
0answers
92 views

Need help in implementing EKF based SLAM

I just started learning about slam and I have been trying to simulate a robot moving around a set of landmarks for the past 3 days. The landmarks have known correspondences. My problem is, if I add ...
2
votes
0answers
101 views

Cognitive Architectures: how do you perform qualitative and quantitative comparisons?

I couldn't find a sub stackexchange for artificial intelligence, but I think robotics comes close, and so I'm posting here. I recently saw TED talks on AI and the Google car, with these being the ...
2
votes
0answers
96 views

choose ZigBee modules for full wireless mesh

What is the most common ZigBee IP Modules to create full wireless mesh mode? I know that it should be 1) coordinator and 2) router to create full-mesh But I am interesting about what kind of modules ...
2
votes
0answers
125 views

Hokuyo URG-04LX-UG01 and Mac compatibility issues

I've got my hands on this laser range scanner but seem to have some problem receiving any output from it. I can't find any guide on how to set it up on the internet, so I was wondering if it is even ...
2
votes
0answers
515 views

Correcting GPS track with visual odometry (sensor fusion)

I am trying to build low cost and precise outdoor positioning. I explored NS-RAW with RTKLIB - this would be doable but probably will need either a base station to get the correction data for rover or ...
2
votes
0answers
907 views

How to connect a servo motor and a crank shaft

I have a standard 5v I am using the horn it came with it, I mean this piece: Like the long arm in the middle. Each of its holes are 1mm diameter. Then I have a 3d printed crankshaft I did: Its ...
2
votes
0answers
114 views

Random number generation for Particle Filter

I implemented a bootstrap Particle filter on C++ by reading few Papers and I first implemented a 1D mouse tracker which performed really well. I used normal Gaussian for weighting in this exam. I ...
2
votes
0answers
117 views

What happened to Butler's car?

Having read the article "This Car Has Electric Brains" in Popular Mechanics, August 1958 I have some questions. How practical were his methods? Was his work acquired by a car manufacturer or some ...

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