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Questions tagged [real-time]

Real-time software is one with tasks that have critical timing requirements. Failure in delivering results within the timing requirement results in catastrophe at worst and uselessness of the results at best.

2
votes
1answer
23 views

How can I measure latency in a CAN bus?

Given a CAN bus with one master and any number of motor drivers, is there a way to measure the time between sending a command from the master (e.g. a PC running ROS) and the execution of the said ...
0
votes
3answers
32 views

The reason(s)/benefit(s) to use realtime operating system instead of while-loop on MCU

I'm working on a wheeled-robot platform. My team is implementing some algorithms on MCU to keep getting sensors reading (sonar array, IR array, motor encoders, IMU) receive user command (via a ...
0
votes
1answer
14 views

RTnet vs CORBA transport

What is the difference between this two. And which should i choose for hard real time control purpose? What are the cons and pros of them one to another?
0
votes
1answer
25 views

controlling industrial servo with pc

these days I'm learning Orocos patched with xenomai. Although I have found the ways to create a hard real-time control software, I didn't find any information on how I should use this to control the ...
0
votes
0answers
11 views

list of robotics framework running over xenomai

Can anyone tell me the list of robotics framework or softwares which can run on xenomai patched kernal like orocos? I was learning orocos this days in normal gnulinux kernal, but after i patch xenomai ...
0
votes
0answers
35 views

warning: target request linking to directory

Im trying to build rtt package of orocos-toolvhain by using cmake .. command inside build folder. when i do so i'm getting below warning. ...
0
votes
0answers
33 views

install orocos-toolchain in xenomai pathced linux?

Can anyone tell me the proper way or give me link to install orocos-toolchain on xenomai patche linux? I have patched xenmai with linux kernel in my system and anslo when i enter "xeno lateny" i an ...
0
votes
0answers
72 views

Required library XENOMAI NOT FOUND

I am following this tutorial to install orocos in my system with ubuntu 16.06, xenomai 3.0.5. But i'm getting error: ...
0
votes
0answers
21 views

controller-youbot: call ros::init() error

I am trying to run run the controller-youbot package from this link. i have build this package succesfully. Now when i try to run the deployer as u can see below it shows some error. i don't know from ...
1
vote
0answers
46 views

rtt-exercise building error-orocos-toolchain

I am using ros kinetic in ubuntu 16.04. My first error is: ...
0
votes
1answer
60 views

hard realtime signal processing

I am going to realize a real time monitoring system for medical care and finally the system should make phone calls according to the severity of the result , I would like to know is it best to perform ...
0
votes
1answer
262 views

Real time implementation of EtherCAT master with ros_control

I want to control a motor using EtherCAT protocol. 1. I used IgH ethercat master to control motor in hard real time (1 kHz). 2. Later I want to integrate this in ros_control with hard real-time ...
2
votes
4answers
174 views

Path of the robot

I have built a simple robot which will move from a source to destination. I want to record a 2d path which the robot has taken in real time. Something which is similar to the image I have take.(...
3
votes
2answers
175 views

Robot Calibration using DH parameters

I'm new in robotics. My problem is the next one: I have a 6DOF robot manipulator and because the implementation was for real-time application my calculation time had to be really fast so that I used ...
1
vote
3answers
79 views

When is the case to use hard real time?

If I use an industrial robot with its hardware controller, should I install linux hard real-time like xenomai to use this kind of hardware controller? If not, when is the case to use xenomai?
2
votes
1answer
191 views

How to eliminate motion blur with realtime performance

I have a robotic system to develop, in first phase of the project I need to track an object. So I placed a geometrical marker on the object to estimate it's pose (rotation, translation). It all works ...
0
votes
1answer
119 views

Robot real time control [closed]

I want to control a arduino based robot in real time , i am confused whether simulink real time control is a better option or Using ROS ?? I am familiar with the simulink , My application is to ...
1
vote
1answer
309 views

Is pyserial real time

I am using arduino with FreeRTOS and a computer with patched xenomai linux. I am using python library called pyserial to communicate with arduino. Right now I am using simple servo motors. I want to ...
1
vote
3answers
2k views

Is it possible to use an arduino in hard real time

I am using the ros_arduino_bridge to control a robot, by connecting the Arduino to a main pc with a usb cable. I was thinking of using the Arduino with main pc with a serial cable and then doing real ...
1
vote
2answers
2k views

Camera selection for long range stereo vision system (up to 100 meters)

I want to implement a real-time stereo vision system for long range (up to 100m) depth estimation. I know that there are some general considerations as described in this SOV post. I have seen some ...
2
votes
0answers
333 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 ...
0
votes
2answers
73 views

How to get live audio from robot?

I am building a robot and I want to be able to hear sounds from it's environment (ideally from my laptop). What is the best way to get live audio from my robot's microphone to my computer? I have ...
2
votes
1answer
70 views

Low latency control from a laptop

Lets say that I needed to send sensor readings in increments of 100 bytes from a micro controller to a laptop with sub 2 ms latencies in real time (the data needs to be processed and acted upon ...
0
votes
1answer
794 views

Quadcopter PID Tuning for Altitude Hold/Position Hold along Z axis

Good day, I have just finished tuning the Pitch and Roll PID's. I did this by setting the throttle such that the quad is weightless. I did the tuning of each axes separately. I would just like to ask ...
1
vote
1answer
128 views

Ultrasonic Sensor's Lag (20Hz) effect on PID contol loop rate (150Hz)

Good day, I would like to ask how is it possible to use an ultrasonic sensor for altitude hold in a quadcopter if the sampling rate of the Ultrasonic sensor (HC-SR04) is only 20Hz before incurring any ...
3
votes
3answers
393 views

Software real-time of ROS system

As far as I know, a hardware real-time robot control system requires a specific computing unit to solve the kinematics and dynamics of a robot such as interval zero RTX, which assigns CPU cores ...
3
votes
1answer
371 views

How does one calculate distance and angle using a target with known measurements?

The target is in the shape of a U where the horizontal segment is 20 inches, and the two vertical segments are 14 inches. We are using a camera to image the target, and then using vision processing to ...
2
votes
2answers
1k views

Real-time camera localisation in known environment

I am young researcher/developer coming from different (non-robotic) background and I did some research on camera localisation and I came to the point, where I can say that I am lost and I would need ...
6
votes
1answer
2k views

Is ROS hard real time safe?

I know that is a question that has been asked too many times, but still its not clear to me. I read online that it isn't but some people say that they control their robots under ROS in applications ...
1
vote
2answers
205 views

Interfacing GPU image processing with motor control at 30+Hz

I would like to make a robotic system which takes as input a video feed, runs some GPU-based image recognition on the video, and outputs commands to a set of motors. The goal is to have the motors ...
1
vote
0answers
98 views

Microcontroller for running Linux RTAI

I'm a beginner in Robotics. I'd like to ask what are the minimum/recommended specs for a microcontroller to run a real-time system such as Linux RTAI? What is the popular microcontroller for ...
1
vote
3answers
329 views

Real time operating system for robotics vision

I have robot vision system which consists of conveyor with encoder, two cameras (gigabit eth and usb) and simple illuminator. I need to trigger cameras and illuminator when encoder reaches position ...
6
votes
3answers
347 views

PID Integration over not constant dt (∆time)

Is integration over not constant dt (∆time) a possible thing? Let's say you have a PID loop with differentiating frequency, can the integral part of it still work? (Assuming you know the dt from the ...
1
vote
2answers
615 views

Raspberry Pi for two wheel robot?

I want to create a two wheel remote controlled robot. I have worked out a lot of the logic with regards to balancing. I have started to read up on motor control and arduino vs beagleboard black vs ...
2
votes
2answers
852 views

Controlling bot using video and image processing

I am going to start a project on controlling robots using hand gestures. Though I have used MATLAB for this purpose earlier, I realized it is extremely slow for any practical real-time system. I am ...
5
votes
1answer
2k views

Python libraries for image processing and feedback control on raspberry pi

I'm building a motion detection and object recognition camera with feedback control for a hexy robot. Fortunately most of the servo control is handled by the analog servo controls and the high-level ...
20
votes
10answers
3k views

How mature is real-time programming in robotics? [closed]

Edit: I don't know why, but this question seems to be confusing many people. I am aware of when/where/why/how to use real-time. I am interested in knowing whether people who have a real-time task ...