Questions tagged [sensors]
A sensor (also called detector) is a converter that measures a physical quantity and converts it into a signal which can be read by an observer or by an (today mostly electronic) instrument.
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Do MEMS or optical gyroscope record Earth's rotational and revolutional angular velocities?
I am using a 3 axis gyroscope (Android device) to record angular velocities using a sensor data logger application.
When the device is placed stationary, the gyroscope recorded the following values:
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Best Camera Sensors compatible with Ros [closed]
I am looking for suggestions for camera sensors (mono or stereo) that are compatible with Ros 2. My research only shows me cameras from brands such as Zed, Luxonis, FLIR, or Orbec. Are there other ...
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Rotation of a point in 3D space
I want to rotate a point (3,4,5) by an angle 45 degrees(0.785398 rad) in 3D space. I have used the standard DCM matrix in the order Rx, Ry and Rz.
Where,
theta = 0.785398,
Rx= ( [ 1, 0, 0]
[ 0, cos(...
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Using an optical mouse sensor for odometry?
I'm trying to use a mouse sensor for odometry on my robot. Most datasheets I have found use SPI or SDIO interfaces for communicating but my microcontroller would require an I2C interface. Would it be ...
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Object racking on conveyor belt using low cost Lidar or similar non-camera options
The requirement is that movement of products right from the start to end of the conveyor belt (of length around 2.5 m) need to be tracked. The same can be easily done using any IP Camera and OpenCV ...
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Rotate sensor frame to body frame
I'm working with a lsm303agr from ST. Here is the frame attached to the chip
Here is the body frame
So I have some doubts about the rotations, before to fuse data ...
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Gazebo Garden plugin and nested models?
I have a problem that I'm not able to solve with Gazebo Garden.
I wrote a System plugin that handles a stereo camera, I need a plugin to interface the simulator with our SDK.
Differently from Gazebo ...
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How does the lightsensor values work? Lightsensorvalue into Percentage
In Webots: I try to build a Braitenberg vehicle so that when it receives light information through the ligh sensors it drives either away or towards the light. I used an ePuck and tried to just ...
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How to read the map output file generated by a project using Cartographer without ROS
Currently I can successfully generate the map output file but I have no idea how to display it in practice. Basically, it should be a 2D SLAM map.
The project I'm using is available at the following ...
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Confused in Regards to Sensor Models, Laser Scans and Ray Castings
I have started studying Robotics recently from Probabilistic Robotics by Thrun Burgard and Fox.
Our objective in the sensor model is to compute
$$P(Z_t|X_t)$$
But for this we need to know $z_{exp}$ (...
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Will there be any interference when distance sensors facing each other?
I'm working a robot racing project using small RC toy cars on a premade track and a main goal for the robots to do is to be able to avoid hitting the wall and the racing opponents. Avoiding wall is no ...
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How to fuse IMU with encoders in EKF
Background
I have a car-like mobile robot (4 wheels, where the forward ones are steering wheels) and I want to estimate its pose and velocity assuming 2D planar motion. I'm trying to solve this ...
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Sensors, ports, pins, drivers and firmware by example
I am looking to just make sure I correctly understand the fundamentals for how robotic systems typically receive and process inputs from sensors.
It is my understanding that a sensor peripheral, such ...
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Are there low cost options for producing high pressure at low flow rates?
I'm looking for a low-cost way for a device to produce up to 4 bar pressure. Flow rate at that pressure almost doesn't matter; 2L per minute would be ample. All the options available seem very over-...
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Joint limits detection
I am pretty new to robotics and I am prototyping my own custom design of a robot with different types of joints controlled by ROS.
I have a custom joint activated by a DC motor and direct drive gears ...
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PID controller feasibility
I'm trying to control a hybrid inverter to manage a selfconsumption mode bypassing its native mode - meaning to distribute power coming from solar and into/from battery to home consumption and grid.
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Where do sensor models come from?
i'm new to robotics. I understood why we talk about probabilities and probabilistic robots, but i don't understand where those probabilities come from, how do i go about building a sensor model? Does ...
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Nao robot IMU data rates
I'm trying to stream data from the Nao's inertial unit in its trunk. However the update rate is quite slow ~ 1Hz. Is there any way to improve it? For reference, I issued the following command using ...
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Force sensors output when inclined
So here is the context:
I am working on a motorcycle simulator. It consists of a motorcycle frame mounted on different actuators (see picture on the left).
In particular, the two actuators at the ...
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Custom sensors and materials simulation in Gazebo: how to simulate specific sensors behaviors for heterogenous materials / buildings
We are currently working on a simulation for a drone that would evolve in an urban environment. It would flight in front of facades and thus must avoid collision into walls, balconies, windows, etc. ...
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Trying to get started with iRobot Create2 - need help reading sensors
I'm getting started helping high school students learn about robotics and we're trying to interface a Raspberry Pi 4 to the iRobot Create 2. I've got them started with some sample code for moving the ...
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GPS + IMU data and kinematics equations
I have the following data
Longitudinal acceleration, $a_x^{IMU}$
Lateral acceleration, $a_y^{IMU}$
Vertical acceleration, $a_z^{IMU}$
Yaw angle, $\psi$
Yaw rate, $\dot{\psi}$
Latitude, $\rightarrow ...
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How can I feel feedback with electric power steering (EPS)?
When I am rotating steering wheel and it meets an obstacle, I feel it. I have EPS. How does it work? Is it just explicit sensor and feedback? Can I sniff this feedback on CAN bus?
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Tips for designing an optical eight channel read head for a DIY rotary encoder
I'm thinking of using the gray code optical encoder disc design described at TeX Stack Exchange to sense the base rotation of a robot arm. Being able to vary the disc to suit the physical aspects of ...
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Real-Time, App-Based Tool Tracking and Inventory Management System
For one of my classes, I need to create a sensor system that can connect with an app that will be able to track when specific tools leave a certain area. I do not know which sensor to implement that ...
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What are common method for sensor feedback in teleoperated underwater ROV to close the control loop
I would like to know what are the common method to get sensor sensor feedback in teleoperated underwater ROV to close the control loop. I mean does it use Velocity or Force and what sensor are used. ...
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Sensor fusion in a metal heavy environment
I am trying to get heading information of a forklift. I've designed a small PCB for this purpose. This PCB has a 3 axis magnetometer and a 6 axis gyroscope-accelerometer (Z- axis looking towards the ...
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Can inferences about servo torque or applied force be made by measuring servo current drain?
I'm working on a robot arm project for hobbyist / learning purposes. One of my DIY motivations is to be able to easily add additional sensors. I've been thinking about using ACS712 linear current ...
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Nonlinear Sensor Fusion with Space-Time Finite Element and Static Condensation?
I have recently implemented an algorithm for the nonlinear fusion of GNSS, barometer, magnetometer, accelerometer and gyroscope data.
The algorithm is based on a space-time finite element where the ...
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How to use knowledge of sensor noise
Reasoning about the meaning of uncertainty of sensor measurement I ran into a doubt:
(1) When we talk about sensor uncertainty, we often model it as a Gaussian distribution $\mathcal{N}(\boldsymbol{z},...
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Can you plug a CMOS camera (like the iPhone 8 back camera) into an mPCIe in a laptop?
I read that 12 megapixel iPhone cameras don’t record video in 12 megapixels because the processors are not able to keep up. It seems though, that if I could plug the CMOS sensor to the CPU of a laptop,...
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how to calculate the accuracy of data received from RTK-GPS?
I have received data from an RTK-GPS, in an environment free from buildings and other GPS obstructions. the covariance of these data is 0.01. now I do not know this is good or not? How can I find out ...
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Attaching an optical rotary encoder to a bicycle wheel
I am currently working on a Sixth-Form experimental physics project, the end goal of which is to build a simplified Malkus Waterwheel, and to see whether chaotic synchronization can be achieved ...
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Data gathering and selling [closed]
a friend of mine is building various Robots with different structures, sensors, limbs executing different tasks. He gathers data from all sensors etc regarding technical and scientific range of ...
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Robotics Structure
I am a kind of a new developer and a beginner in Robotics and AI. I am currently learning using the Arduino Uno starter kit. My knowledge on C & C++ is on the beginner's level but i get the whole ...
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What kind of distance sensors should I use for outdoors applications?
I want to measure two or more distances between two or more sensors and a truck-trailer front face in an outdoors (night/day, rain/shine) environment. I've been looking at the different types of ...
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How to create pseudo code for Braitenberg vehicle 2b?
I am asked to make Braitenberg vehicle for small robotic exhibition. I am asked to use GL5528 light sensor. My job is to construct and program Braitenberg vehicle 2b, which uses GL5528 light sensors ...
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How to set "fast mode" in low cost DRO
I have this cheap DRO from Amazon/China
https://www.amazon.com/gp/product/B00E7XFF5Q/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1
I'm able to read the values out of it using a small FPGA.
The ...
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Force-torque sensor reading when a robot is stationary
Let's say I have a robot arm with a force-torque sensor on the wrist, between the final motor and the gripper. If the arm and wrist are stationary, then what would the reading on the sensor be?
I know ...
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Looking for a wheel
If this is not the right community please point me in the right direction.
I am looking for a speed measuring wheel similar to the one in the picture..
What is it called?
I have googled for a ...
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Underwater navigation without the use of acoustic sensors
I have been reading about different types of underwater navigation.
According to this Youtube video, these are the following navigation systems:
Inertial navigation systems (use of Inertial ...
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Can I measure torque from this motor by only measuring the current?
I am new to robotics, please forgive/correct any errors.
My Project Plan
I want to use a PID controlled motor in a human-interface device where I need to measure the user's exerted force on an end ...
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please identify this switch
can anyone identify this switch type, please? I've been looking all day at various websites. I'm just looking for a very simple touch sensor, and this seems ideal
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Create2: Getting strange data reading sensor data
I am new to Create2 and I hope someone can help me.
I have a problem with reading the sensor data or the data I get.
I have setup a nodeJS application running on a Raspberry PI 3B+. Sending data (e.g: ...
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IR Sensor to detect fast moving object
I have a somewhat specific need for a project I'm building: I am trying to create a sensor grid of 1.5m height by 2m wide that has to be able to detect objects, ~10cm in diameter, in potentially ...
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How to make my robot move parallel to edge of the table?
I have an autonomous differential drive robot that moves on the floor and its purpose is to always move parallel to the longer edge of the table (just assume that the table never ends). It looks ...
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Barometer altitude calculation
I want to calculate altitude using a barometer which is mounted in the proximity of a number of components which get quite hot and raise the localised temperature. The barometric pressure equation is ...
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Detection of linear acceleration vs rotational velocity/acceleration
I am wondering, how do you differentiate between linear acceleration and rotational velocity and acceleration for IMU? A rotational velocity or acceleration will still appear to the accelerometer as a ...
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For a quadcopter do i need to place the gyroscope sensor at the center of mass?
I am trying to build a quadcopter and think it is essential to have its center of mass in the middle. Therefore, I am planning on putting the battery in the center. However, this will cause me to ...
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Does an S type load cell need to be loaded perpendicular to its screw holes?
I know that a bar type load cell needs to be setup as shown here as to flex the strain gauge
However, most tutorials or guides show how to setup an S type load cell like this (for tension)
and not ...
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