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9 views

DC motors are stalling at low voltage (L298N controller)

I'm building a small tracked robot. Currently it's just a Raspberry Pi, two motors and an L298N controller. The problem I'm facing is that the motors are stalling at low voltages (which is what I ...
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0answers
7 views

AC Motors vs Hydraulic motors for skid-steering robot

I'm designing a mobile robot with tracks and skid-steering driving system and I am evaluating whether an electric motor would be better than a hydraulic one. I did some calculations, the total weight ...
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0answers
6 views
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1answer
14 views

Understanding types of hand eye calibration

This is my first question, so pardon me for any mistakes. I have been reading about hand eye calibration for a couple days. Basically, I have 2 setups I want to execute hand eye calibration. Camera ...
0
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1answer
15 views

Ros sensor implementation

From this page, there are lots of sensors to be used in ros robots. http://wiki.ros.org/Sensors but I could not install any of them to the robots in my simulations. For example I want to install ...
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0answers
11 views

Compute tangential acceleration of a specific point using IMU data?

I have a question about using datas coming from an imu on a vehicle. The IMU is placed near the rear wheel axle of the vehicle. The reference frame for vehicle control is placed between rear wheels. ...
0
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1answer
20 views

Problem understanding a paper about visual odometry

I am reading the following paper: SVO: Semi-Direct Visual Odometry for Monocular and Multi-Camera Systems , and I am having some problem understanding some concepts. Before starting I have to say ...
1
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1answer
14 views

Self motion with multiple constraints

I am trying to control a 7 DOF robot (a Franka Panda). I use jacobian based control (resolved rate motion control) to generate a joint trajectory from a cartesian trajectory. My contraints for the ...
0
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1answer
17 views

I2c arduino connection

I am working on a wheel mobile robot which with multiple sensors which are IMU, two encoders, four ultrasonic sensors and using two Arduino: Uno and Mega. The IMU, encoders and the ultrasonic sensors ...
1
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1answer
25 views

Using Integral gain for motor positioning

I'm struggling to see how Integral gain is used for motor positioning (with an encoder on the shaft). Suppose we have an AC motor connected to a winch which drives an object forwards and backwards. ...
1
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1answer
23 views

What should be the prediction step in particle filter?

I am implementing a particle filter using MATLAB. I am implementing it first time. I have written the system model and measurement model. Given below: ...
1
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0answers
14 views

Use polynomials to detach number of MPC controls from size of time-horizon?

Model Predictive Control (MPC) works by finding a set of controls $u_0, \dots, u_n$ that minimize a cost function $J$ over a time-horizon $[t, t + T]$. Typically when MPC is used on mobile robots, ...
2
votes
1answer
26 views

Path finding: A* vs Fast marching

Context: I am working on a 20 cm x 20 cm indoor robot on a 2D terrain and I need to decide on its path planning algorithm. Algorithms: A* and Fast marching are two popular (and fundamentally ...
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0answers
7 views

What servo and controller to use on a o scale model to make a rocking chair move up and down [closed]

I’m trying to design a rocking chair to move back and forth on a O scale diorama and I would like to know what type of servo and controller to buy to achieve this
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1answer
14 views

Understanding KGf.CM in Camera Robotic Head Design

I am attempting to design a robotic camera head - however, I am struggling to calculate the torque (in terms of KGf.CM) I will require to rotate the Y (tilt) axis of the head. The motor I intend to ...
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0answers
17 views

I want interpolate my data in python. How we can do that? [closed]

I have created 3D volume and then sliced that volume in horizontal planes. After that, I cut all the planes in different shapes vertically. I got some points on each horizontal plane. I want to ...
1
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1answer
38 views

motion model for forward movement

I thought this is a simple and well known problem and therefore there is a lot of literature. But I'm not able to find the correct keywords to google the answer. Maybe instead of answering the whole ...
0
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1answer
23 views

What is wrong with the assignment of X axis in 5DOF robot manipulator's kinematic diagram?

I tried to solve below question by Edx course. One part of the requirement was to assign frames and find the DH parameters of the given robot manipulator. I assigned the x and z axis as below and find ...
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0answers
24 views

How many DC's I need? [closed]

How many DC's I need to move 4 kg object? Speed doesn't matter. • Voltage: 3-6V • Amps: 80mA (6V no load) • Stall amps: 1200mA (6V) I couldn't find more specifications. Could you make assumptions ...
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1answer
22 views

Data collected from ROS

How can we collect the flight data after a ROS simulation and what kind of dataset do we obtain? Can we get the sensor and video dataset with timestamps to be used in analysis?
0
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1answer
11 views

Numeric integration problem in a quadrotor vertical descend code

I'm trying to implement a drone in vertical descend. As for maximum simplification, I maintain all its angles to 0, and just try to get to the my desired descend. However, when I debug, I see that my ...
0
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1answer
41 views

Applications of Reinforcement Learning

Many global-control applications of robotics involve incomplete world information and at best can be represented as a POMDP. Given this, can we really apply RL to most robotics applications? From ...
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0answers
43 views

Extended Kalman filtering for IMu and Encoder

I am trying to fuse IMU and encoder using extended Kalman sensor fusion technique. how do I fuse IMU pitch, roll with the orientation data I obtained from the encoder. Also, how do I use my position x ...
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0answers
15 views

Algorithm for Collision avoidance of Multi Robot system on a predefined path without external obstacles ( collision might occur only with one another) [closed]

I am trying to solve a question on junction management of multi-robot system (N number of robots) which have to cross a 4-way junction without collision with each other ( kind of like cars on traffic ...
1
vote
1answer
28 views

Verifying DH parameters. Unexpected Output

There is a rotating base joint #1 with z/joint axis pointing up and atop sits and arm with 3 z/joint axis facing away from the viewer. The elbow joint F2 has a kink before it of 90 degrees measuring ...
3
votes
2answers
117 views

How can I calculate odometry given two poses?

I have the pose at times t - 1 and time t. We are given: that the the new pose, at time t, is $$x_{t - 1} = [0,0,pi/6]$$ $$x_{t} = [0.2,0.1,(11*pi)/60]$$ (Where the vectors are [x, y, theta] with ...
1
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0answers
21 views

Link collision avoidance for redundant manipulator

I am trying to have my robot arm follow a trajectory while avoiding collisions between obstacles and the robot links. The way I go about it is to find the closest point on the robot arm, and treat the ...
0
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0answers
29 views

FPGA vs Neurochips for Control Systems [closed]

Greetings to all respected colleagues! I want to consult on the use of FPGAs and neurochips. I plan to use it in my laboratory project for programming control systems on neural networks. Please share ...
1
vote
1answer
38 views

Dual constraint non-linear optimization for SLAM

I am trying to achieve a nonlinear optimization for SLAM on a function that contains two different constraints, like this : $$ T_{opt} = \underset{T}{\arg\min} \sum_i(\left\lVert T.X_i - x_i \right\...
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2answers
41 views

Path planning algorithm better than RRT* and Artificial Potential Field

Hello robotics stack exchange community, hope my message finds you well during these challenging times. I need an opinion regarding path planning algorithms. Goal I am looking for a path planning ...
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0answers
9 views

Navigation Function : Sphere Spaced Set

The navigation function in a sphere spaced set is given by: Equation How do I determine the value of Lambda?
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0answers
11 views

Tuning a cascaded attitude and attitude rate PID controller

Assume that I have an object in 3D, and I want to have a controller that stabilizes its orientation (also referred to as "attitude"). To be sure we are clear: attitude is measured in "degrees" or "...
0
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0answers
10 views

accuracy GPS for height measurement [closed]

what is the maximum accuracy of GPS module including lat, long, and altitude. I need GPS module with max accuracy of altitude for height measurement.
1
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0answers
28 views

how to calibrate gyroscope using raw gyro data?

I wrote a simple code for where I take 500 samples with stationary gyro and subtract those offset values to get calibrated gyro data. Question: Is this much calibration enough to implement this gyro ...
0
votes
1answer
30 views

Good Software Projects for Aspiring Engineers [closed]

With the pandemic going on, our school has decided to officially shutdown all sponsored club meetings. Now that we are all digital, our robotics club was looking for projects that students can do at ...
1
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1answer
33 views

Inverse Kinematics for 4 legged robots and body translation

The prompt here is to implement the IK on a real robot with constraints. I started off with writing the DH-Table. $\begin{bmatrix}n & a_{i-1} & \alpha_{i-1} & d_i & \theta_i \\1 & ...
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0answers
15 views

Industrial robot kuka210 wobbling/vibrating in gazebo environment

i have spawn a kuka210 robot in gazebo but the robot is wobbling i tried to make change in urdf file and gazebo_control.yaml file, according to the given solution but it could not help, Why my robot ...
0
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2answers
73 views

Difference between SLAM and Localization

What are the differences between SLAM and Localization if you have a known map? How does the position probability update differ between the two? In particular I'm curious on if localization is a ...
0
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0answers
19 views

Algorithms for IMU sensors calibration in real time on arduino due?

Im working on a 10 DOF IMU system for quadcopter project. I understand the need for sensor calibration but uptil now I have seen offline ways to compute the calibration offsets/biases, where we take a ...
1
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0answers
10 views

Does GY-271 (HMC5583L) or any 3-axis magnetometer suitable to detect orientation?

Based on the datasheet, HMC5583L has 160Hz output rate and produce three axis direction angle data, X, Y, and Z. It can measure diversion from Earth magnet field with 1° to 2° accuracy. Does that ...
0
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0answers
15 views

Proper Joystick Inputs for UAV Quadrotor Control

I am working on the adaptive control of quadrotor UAV in MATLAB/Simulink environment. I prepared some trajectories for the UAV to follow in $x$, $y$ and $z$ directions. I would like to implement these ...
0
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0answers
26 views

What happens when I send the land command to my quadcopter?

My first question is: imagine I have a self-made quadcopter and I want it to land. How can I achieve that? Do I have to stop the 4 motors at the same time? Second question: I use an AR.Drone 2.0. ...
0
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0answers
23 views

Quaternion Multiplication Order: Extrinsic rotation vs Intrinsic rotation

My understanding $q_1, q_2$: Rotation quaternions, i.e. $|q_1| = |q_2| = 1$ $Q$: Composite rotation which first applies $q_1$, and then $q_2$ When $q_1, q_2$ are extrinsic rotations, which are about ...
0
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0answers
21 views

How to create a jumping mechanism for a small robotic car?

I have to create a jumping mechanism for a small robotic car and was thinking about using a spring mechanism to do so. However, due to dimensions (16cmx8cm) and mass constraints (below 200g) I cannot ...
1
vote
0answers
22 views

How do I convert centre-returning joystick values to dual hobby-motor direction?

Currently my setup is: 2x hobby TT motors connected to a Pi Zero with a motor HAT Python script running on the Pi which runs a Blynk python client and controls motors via the gpiozero library Blynk ...
0
votes
1answer
46 views

Free 2 and 3d simulators [closed]

What physics simulators exist which are open source/free? AI Gym uses a proprietary for-cost physics engine making it nonviable.
0
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0answers
22 views

Does iRobot Roomba 606 have a wifi chip?

I just bought an iRobot Roomba 606 and am trying to customize it with create 2 documentation based on Roomba 600. I opened up the Roomba, and over the board, it says "R3 MAIN, WIFI". It doesn't say ...
0
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0answers
20 views

I want to Calculate the Joint Velocities and Angular Accelerations of 5 DOF Youbot kuka robotic arm

I'm working on an assignment where I need to derive Velocity Kinematics for 5 DOF Youbot kuka robotic arm manipulator. I want to Calculate the Joint Velocities and Angular Accelerations of 5 DOF ...
2
votes
1answer
22 views

How do “process gain” and “proportional gain” affect the Steady State Error in a PID Controlled machine?

I came across this doubt while reading the Wikipedia page on PID Control. The section on Steady-state error states: Steady-state error (SSE) is proportional to the process gain and inversely ...
0
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0answers
13 views

Must link length should be very accurate for DH parameters?

I am trying to implement the inverse kinematics of SainSmart 6DOF robot manipulator in MATLAB by using robotics toolbox. I draw the kinematic diagram of the robot arm and calculated the DH parameters ...

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