9
votes
Camera selection for long range stereo vision system (up to 100 meters)
I still think this is off-topic, but it seems I need more space than a comment to show (answer?) why that is so.
You are starting from some performance specifications and are looking to get to a set ...
- 15.9k
4
votes
Accepted
Why does ROS2 claim to be "real time"?
"Realtime" is a fairly vague term. What ROS is referring to is often termed "soft realtime" because it is able to calculate control actions as fast enough to keep up with the robot'...
- 2,794
4
votes
What is the best adaptive controller for robotic arms?
The given strategies can be divided into two groups: model-based and model-free control. The AMPC and MARC suggestions are model-based the other are model-free. Theoretically, a pid controller can be ...
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4
votes
When is the case to use hard real time?
In general, hard real-time OSes are used when there is a (usually periodic) task that is terminally critical, i.e. a process that needs to be run every few milliseconds, for example, and which, when ...
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3
votes
Camera selection for long range stereo vision system (up to 100 meters)
I'll try to explain this in terms of software. Firstly, it is just next to impossible to have 100 metres (practically, 3 metres is like the best depth accuracy) and we need to be sure that the cameras ...
3
votes
Software real-time of ROS system
You can use Orocos RTT with ROS to achieve some real time performance. In order to use this you need to patch the Linux kernel with a real time patch like PREEMPT_RT or run a real time kernel like ...
2
votes
Real-time camera localisation in known environment
The problem you want to solve is definitely a SLAM problem and not just simply localization (or maybe we can consider it SLAm since the mapping part is not as heavy). The reason for this is that you ...
- 1,377
2
votes
Real-time camera localisation in known environment
As a matter of fact, if the environment is known a priori, then you don't need SLAM. It is a matter of localization problem which is simpler than SLAM in the sense that the map is given, therefore you ...
- 2,453
2
votes
Accepted
Quadcopter PID Tuning for Altitude Hold/Position Hold along Z axis
Currently I am performing my research on that, and in my case I decided to tune all the PIDs. Angles of the quadrotor tend to zero, while altitude controller tend to the objective height. That's ...
- 470
2
votes
Accepted
Path of the robot
One of the ways to do path tracking is by indoor mapping. In indoor mapping you can use Triangulation method. Basically, this method uses the help of Relative Received Signal Strength (RSSI) from ...
- 179
2
votes
Accepted
hard realtime signal processing
This sounds like a great project.
You should have a list of at least 20 processors from at least 10 companies that you are choosing from when starting a new project. Understand your requirements and ...
- 4,355
2
votes
How can I measure latency in a CAN bus?
Use an oscilloscope.
Place oscilloscope probes on an i/o line on the master and a motor phase line on the slave. Toggle the i/o line just before sending the can bus command for a step change in the ...
- 4,355
2
votes
Real Time Motion Control
The key elements to real-time motor control is the motor controller and the motion controller (which can be a CNC, a robot controller or other type of controller). The following description fits most ...
- 6,632
1
vote
Accepted
Time synchronization
This is a confusing question for me because I don't understand why you're looking at the device if you're not sure what it does. Was this recommended to you? By whom? What did they say when you asked ...
- 15.9k
1
vote
How to keep a sensor pointed downward
Your LIDAR will need some active stabilization. Under gravity alone it will sway like a pendulum.
You could start with a web search for "servo gimbal". Resulting hits show complete devices, ...
- 1,271
1
vote
Robots and RTOS
The answer is yes, for example many robot computers are based on the linux real-time kernels to handle the real-time constraints.
For small robots for teaching like the turtlebot uses a raspberry pi ...
- 497
1
vote
Accepted
Is it possible to use ROS2 real-time on a computer and connect to the robot actuator using a CAN bus?
First, you should define what real-time requirements do you have, not necessarily from a CAN-Bus, but from the application perspective. What is your cycle time, what latency can you accept, what ...
- 6,632
1
vote
PID control loop and feedback acquisition synchronization
This kind of control situation in general Nyquist method is used, In your first if your sampling period is 4 ms, your sampling frequency is 250 Hz, so you can control event maximum 125 ...
- 11
1
vote
Head movement using gyroscope
You would have to integrate the rotational kinematics equations forward in time with a known initial orientation, such as R(0) = eye(3,3) -- identity matrix. You will have drift issues if you go out ...
- 11
1
vote
The reason(s)/benefit(s) to use realtime operating system instead of while-loop on MCU
Using an RTOS on a microcontroller is for reducing the complexity of developing your solution, and reduces the need for programmer expertise for device drivers, at cost of increasing the complexity of ...
- 4,355
1
vote
Accepted
controlling industrial servo with pc
Real-time control protocols for drive amplifiers are Ethernet based, but not necessarily compatible with your average Network card.
You can take a look at the following protocols and decide which is ...
- 6,632
1
vote
Real time implementation of EtherCAT master with ros_control
You would confuse or mislead people if you called a non-realtime system with realtime subsystems a realtime system.
If your motor control is realtime, just say that. That you have realtime control of ...
- 4,355
1
vote
Path of the robot
Since you have servo motors, you can record a sequence of motor rotations when you teach the path, then have the robot repeat these saved values as an array of destinations when you repeat the path. ...
- 4,386
1
vote
Path of the robot
I would recommend rotary encoded motor mostly used to track no of rotation(steps) used in roomba vacuum cleaner to record steps and compute if needed
- 41
1
vote
When is the case to use hard real time?
You should find it useful to read this https://www.researchgate.net/project/A-Preview-of-Introduction-to-Fundamental-Principles-of-Dynamic-Real-Time-Systems. "Hard" real-time is a special case of the ...
1
vote
Accepted
How to eliminate motion blur with realtime performance
You don't need more frames per second, you need a shorter exposure time.
- 1,843
1
vote
Accepted
Is it possible to use an arduino in hard real time
The short answer is no, you will not be able to create a distributed system that meets the criteria of 'hard real time' using the approach you describe.
The more nuanced answer is: It is ...
- 4,355
1
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Is it possible to use an arduino in hard real time
There are multiple different parts to your question.
Can an Ardiuno be used "in in real-time"?
Yes it can, it has hw timer interrupts, the tolerance of your oscillator will give the precision of the ...
- 6,632
1
vote
How to get live audio from robot?
Look into soundwireserver. Its an easy way to setup an audio server on a Linux or windows based system, and can be monitored from a laptop or an android phone. You need to consider processing ...
- 157
1
vote
How does one calculate distance and angle using a target with known measurements?
I would suggest model based pose estimation. DeMenthon and Davies describes a method for finding the pose of an object using 25 lines of Code!
- 47
Only top scored, non community-wiki answers of a minimum length are eligible