# All Questions

4,435 questions
1answer
15 views

### bluetooth that could track mobile phone location

newbie here. after my research, i couldnt find anything that could found what i wanted to search for my project(following robot for indoor location). without gps, bluetooth only, could i get the exact ...
0answers
23 views

### FastSlam2.0: ICP Scan Matching vs Odometry? What is the typical time step?

When working with a FastSlam2.0 algorithm, ICP Scan Matching is supposed to give more accurate measurements than odometry. The problem is, that given some noisy measurements from the laser scanner, ...
0answers
21 views

### How to quantify motion? [on hold]

I am working on a calibration algorithm where the motion is related to the observability of the parameters that I am calibrating. Let's say we have a 6 dof trajectory and wants to quantify its motion ...
1answer
14 views

### motor controlled lazy susan

I'm trying to figure out an easy lazy susan setup. This is for video production, I want to be able to put an object on the platter and get a smooth consistent turn in order to shoot the object ...
1answer
20 views

### Can a neural network emulate a physics engine?

Before a motion controller for a robot can be created, a step before is needed, called “system identification”. The aim is to create a prediction model which can say, what will happen if a certain ...
2answers
32 views

### Libraries to simulate path planning in a dynamic environment for a 2D space

I need to simulate a path planning approach for a 2D space where the obstacles are moving. Initially, I need to implement probabilistic road map, D* lite, A* and Bug2 algorithm. The robot needs to be ...
5answers
1k views

### What are the reasons for not having autonomous robots in our daily activities?

The fact is that the more I search the less I find autonomous (real) robots in use. The companion robots are all toys with limited useless functionality. Whenever there is a natural disaster you don’t ...
0answers
33 views

### What is a good way to measure the perpendicular distance to a laser beam? [duplicate]

What is a good way to measure the perpendicular distance (from a mobile robot eg) to a laser beam?
1answer
38 views

### Head movement using gyroscope

I have a headset that provides 3 axis gyroscope readings. I wish to find out movement of head for e.g. if a person is nodding left to right etc. But the headset give me values in angular velocity for ...
1answer
14 views

### How can i find and install (acspid) python PID library

How can i find and install (acspid) python PID library in the folowing code import acspid pid=acspid.pidcont(1.2,0.02,0.01,5,-5)
1answer
34 views

### How can I preserve a high framerate while using at least 1280x720 resolution on 2 USB cameras on the same computer?

To expand on this, I have a down-facing camera using the whycon ROS node on Ubuntu 16.04 Kinetic on a quad-core computer with 640x480@60fps MJPG video. I'm also using the ...
0answers
34 views

### How to handle sensor data for a sensor-fusion algorithm

I am implementing the explicit complementary filter(see below) with a 9DOF MEMS sensors (accelerometer, magnetometer and gyroscope) for attitude estimation. Currently, the gyro and accel update rates ...
1answer
29 views

### What is a Velocity Smoother?

I'm learning ROS and I have found an expression that I don't understand. I'm reading the book "Mastering ROS for Robotics Programming - Second Edition", and on a controller to move a robot using ...
0answers
29 views

### Choosing a position sensor (encoder) and obtaining velocity from it

How do I know how many counts per revolution I need for an encoder for my application? I need to be able to accurately capture a 1000 Hz signal on an input side running from 1-133 rev/sec (60-8000 ...
1answer
22 views

### How to perform active search in point feature based monoSLAM?

I am modifying an implementation of SLAM with single camera, MonoSLAM [1]. Instead of image patches, I want to use features points (ORB) to track landmarks. MonoSLAM uses a EKF framework. So for ...
1answer
1k views

### Choosing the right dimensions for an underwater glider

I'm looking to potentially build an underwater glider, a type of submarine that's slow but can operate on extremely low power draw. However, in order for it to work effectively I've found several ...
1answer
28 views

### Please help me with stall property of gear motor

i have read a spec. about gear motor and it shows that Stall: 9-13 Nm torque 25A max Per my understanding Stall torque is the maximum torque that can be applied to the shaft and cause the ...
1answer
37 views

### Are underactuated robots easier to program?

The first examples for passive dynamics were introduced by Ted McGeer in the early 1990s. The main principle of so called underactuated robotics is, that not all joints in the system can be controlled ...
1answer
51 views

### Is robotics and automation a contradiction?

With the Meccano toy it is possible to construct a variety of useful machines. For example a knitting machine, a loom or a steam engine. What these machines have in common is, that they are doing ...
1answer
22 views

### How can i connect arducopter to raspberry?

This is my school project. I would like arducopter connect to raspberry but I do not know how to do it. Please help me!
0answers
21 views

### Combining P and D gains properly

I'm trying to perfectly tune my quadcopter and I'm at the point where P gain feels about right as it tracks my stick movements perfectly, yet it wobbles after a sharp stick input. If then I raise my D ...
1answer
451 views

### Vex motors and tank treads drained 9-volt battery more quickly than expected

I've got a couple Vex 269 Motors hooked up to an Arduino Duemilanove. These motors run a some Vex Tank Treads. I powered the whole setup with an off-brand 9-volt battery. Everything seems to run great,...
1answer
30 views

### Loop time for self balancing robot

I have been working on a self balancing robot and there are quite a few parameters and one of them is loop execution time (t_loop henceforth). To my understanding, the smaller t_loop, the better it is ...
1answer
25 views

### Is system identification and a physics engine the same?

In the control theory the term “system identification” is used quite often. A typical sentence in a robotics oriented paper is that the author is trying to “build a model of a plant with matlab”. The ...
2answers
223 views

### Should I use an arduino to control my balancing robot's motors?

I'm building a 2-wheel balancing robot from old parts. DC motors from an old printer, wheels from a BBQ, bodywork from an old optical drive etc. The brain of the robot is a Raspberry Pi 3. I'm using ...
2answers
52 views

### I must determine the resolution of a control system when using an 8-bit encoder for a single-rotation joint

The length of the link is 50 cm and the arm moves 180 degrees. Can anyone help me? Out of the cosine theorem, $d = \ell \sqrt{2\left(\ell-cos\right)}$, I calculated the distance traveled by a linear ...
2answers
51 views

### underactuated robot problem

Lets say the robot has 4Dof and the operator gives (x,y,z,roll,pitch,yaw ) as control input( rank(J) < dim(task) ). Now the robot is overwhelmed and will probably show some jerky movement. But can ...
0answers
15 views

### Inexpensive & minimally viable systems for testing SLAM algorithms?

I've been studying SLAM on my own for some time, I can sift through texts over texts and try my best understanding them. However, without actually implementing them myself, I think I still don't fully ...
0answers
8 views

### Connecting a Roboclaw 2x15a to an Arduino

I'm new to robotics but have a background in programming. I recently purchased an Arduino Uno starter pack as well as a Roboclaw 2x15a motor controller with 118 RPM motors from ServoCity. I haven't ...
1answer
31 views

### How to determine the rotation matrix and translation vector of a fixed LiDAR from the sensor frame to an aircraft's vehicle frame?

I am using a fixed 3D LiDAR sensor on a small aircraft. The vehicle has a GPS/INU to calculate its own position and orientation. I do not know the exact offset of the LIDAR from the center of the ...
1answer
35 views

### Humanoid Robot Arm

I have a modeling design for Humanoid robot arm in simscape-SimMechanics in Matlab, I am trying to use the inverse kinematic to make a reaching movement for the arm to the target position; however, I ...
0answers
4 views

### L298N briefly works, then shorts when controlling Nema 17

I'm trying to control a Nema 17 stepper motor with a L298N H-Bridge. My wiring is as below (except I'm using a ESP8266 not a YUN, and I have a mains 12V supply rather than batteries). This is ...
1answer
20 views

### Accuracy of hall sensor encoders on Raspberry Pi

I have 2 motors (JGA25-370) with hall-sensor encodes. They emit about 90-100 interrupts every 100ms, so 1000 a second. Which means I have an interrupt happening every 1ms. The motors are driven by ...
1answer
22 views

### Controlling YuMi robot by serial port

I'm trying to control the YuMi robot arm by a serial port. The serial port will give the information on what direction the end-effector should move and what is the velocity. What I would like to ...
1answer
30 views

### Trajectory following- What if the robot joint motor are not able to keep up with the generated trajectory?

I want my robot manipulator to follow a user-defined path. Based on the waypoints given as input and the velocity and acceleration limits of the joint motors, I generate a trajectory. At every time ...
1answer
24 views

### Localization in box using rangefinders

Let's say I have a robot, located in a box. The robot can move in the x and y and rotate. The robot has 4 rangefinders, mounted 90 degrees apart, that measure the distance to the walls of the box (I ...
1answer
31 views

### Quaternion error in one degree of freedom

I would like to control a system which orientation I measure with as quaternion based EKF in one degree of freedom. Obviously the simplest thing would be to convert the quaternion estimate to euler ...
0answers
17 views

### What is a good way to measure the perpendicular distance (from a mobile robot eg) to a laser beam?

What is a good way to measure the distance (from a mobile robot eg) to a laser beam? The purpose of course is for the mobile to track the laser beam. The mobile may go temporarily off the beam by ...
3answers
85 views

### Inverse Kinematics Problem of Articulated Manipulators Arm

I have a robotic arm consist of three joints (servomotor for each joint), as shown in the figure below: Notes: Each servomotor rotates around 180 degrees. The angles of the theta2 and theta3 ...
2answers
46 views

### How a quadcopter pitch/roll impacts thrust?

I'm thinking about how a quadcopter flight controller works, and I usually see that each motor speed is determined by a formula like: ...
1answer
28 views

### Convert local coordinates of a moving IMU to global coordinates

I am trying to compare the performance of an IMU in motion against an optical tracking system. The IMU has an accelerometer and a gyroscope and gives output in the local IMU coordinate frames. The ...
0answers
6 views

### iRobot Create 2 Wake over Serial on Rpi

So this thread is similiar to this one: IRobot Create 2: Powering Up after Sleep All except I am trying to do this on an RPi. I have followed these intstruction: https://www.irobotweb.com/-/media/...
0answers
8 views

### Problem with UKF weights when calculating predicted state

I'm having troubles implementing a UKF during the calculation of $\overline{\mu_t}$, specifically in this step: $$\overline{\mu_t} = \sum_{i=0}^{2n}w_m^{[i]}\chi_t^{*[i]}$$ My problem I'm facing is ...
0answers
19 views

### I need to read a lot of analog signals without any analog pins

I have an nvidia xavier with gpio running linux. It should work very similarly to raspberry pis. I need to connect a bunch of pressure sensors, thermistor, potentiometers, and vibration sensors to my ...
0answers
24 views

### How to calculate observation matrix Jacobians in EFK based mono slam? What are projection Jacobians?

I have been trying to understand an implementation of monoSLAM 1. But my question is generic to EKF based single camera SLAM. My Jacobian calculation leads to complex and lengthy expressions while ...
2answers
26 views

### State-vector for distance measurement between two autonomous cars

I hope someone can help me: Given two autonomously driving cars, I want to make sure they keep a constant distance to each other. For this purpose, I want to design a Kalmanfilter. Typically, the ...
1answer
127 views

### rospack Error: package 'script' not found

I am trying to run rosrun script forward.py but it gives me an error saying [rospack] Error: package 'script' not found In my ...
1answer
30 views

### How should I power my servo motor with the Adafruit PCA9685 chip?

So I have an Adafruit pca9685 controlling an HSB-9380TH servo and a MG-996R servo. I recently began learning about building robot so I apologize if these questions seem dumb. I literally spent a days ...
1answer
41 views

### Why can't motors be as elegant as human muscles? Why do we have to use electromagnetism to create movement?

Pretty much as the title says. Why isn't it possible to build motors as microscopically and simply as they're built in humans? Why can't we recreate electronic nerves and muscles?
1answer
30 views

### Which sensors can be used to feel breeze blowing by the robot?

Am faced with a situation where my robot needs to feel breeze blowing by over its artificial skin. While there exist many types of tactile sensors, nothing seems to fit the bill. I might abandon the ...

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