Questions tagged [control]
A method or device to manage, command or regulate some part of a system.
497
questions
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19 views
Non-linear MIMO system inverted pendulum controller [closed]
We have a big problem. We are trying to work on a controllable inverted pendulum, however we are stuck.
We want to control all angles, using the fact that we can control all torques. The differential ...
1
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0answers
17 views
implement torque control on a robot with some joints supporting torque control while others only supporting velocity control [closed]
I have a robot, some joints of which supports torque control,while the rest only supports velocity control. What should I do to implement torque control on the whole system?
0
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1answer
38 views
What are some recommended mathematical courses to understand robotic systems? [closed]
I would like to know what mathematical courses would help me understand robots better.
Certain mathematical concepts seem important to know because I have heard roboticists talking about them. For ...
0
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1answer
49 views
Why are the angular velocities of concentrated masses in Lagrangian independent?
There is an ordinary linear three-mass system.
If we write its Lagrangian, we get the following equation.
where $W_k$ and $W_n$ - kinetic and potential energy.
To find the moment of rotation of the ...
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0answers
29 views
Robot-telescope prototype controlled by a PC
Has anyone developed mechatronic systems for DIY-telescopes running a PC?
Please share your experience, knowledge and nuances (how you acquired current sensors, speeds, electric motors, about ...
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vote
2answers
53 views
Dynamic models of parallel robots in the form of multi-mass systems with stiffness coefficients
I want to develop a dynamic model of a parallel robot for control tasks. It is known that equations of motion based on Lagrange equations can be transformed into a state space and use such a model.
...
0
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1answer
63 views
Modeling of Robots
There are mainly two approaches for controlling robots (mobile robots and static robots): 1) working with kinematic equations, controlling joint or wheel speeds , 2) working with dynamic equations and ...
0
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0answers
11 views
Extract Coriolis matrix from Coriolis*q-dot vector multiplication
I have been using matlab to do some robotics simulation.
I am able to
Create the forward kinematics with transformation matrices
Create the jacobian matrix
Find joint velocities
Create the ...
0
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0answers
23 views
MAV drifting away from its takeoff position
I am working on MAV control in GPS denied environment using px4flow and Lidar sensor.While in simulation and during experiments on real vehicle, MAV doesnt stay at its position and drifts in random ...
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0answers
22 views
About the commonly used equation of distributed consensus of multi-vehicle systems, is this form correct?
$\dot \epsilon = -(L_{n}\otimes I_{m})*\epsilon$
This equation is commonly cited in works about the distributed consensus of cooperative control. In fact, it's the matrix form of the basic consensus ...
0
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0answers
20 views
How to avoid singularity in ABB robots while using it with EGM (externally guided motion)
I am using the IRB120 robot and controlling it with Azure Kinect body tracking data. I am using EGM as an interface to pass the data from kinect to the ABB robot.
But here sometimes the robot stops ...
0
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3answers
50 views
Implementation of Velocity Control Algorithm Based on PID
I'm very familiar with the traditional position form of PID. The error is just the difference between some setpoint encoder value and the current encoder value. Although this suffices for basic ...
7
votes
2answers
82 views
Motion Planning vs. Control
Often I see positions for robotics companies split into planning and controls engineers.
But motion planning and controls seem to have a lot of overlap.
As I understand in motion planning the ...
0
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2answers
60 views
Multithreading on robot control
Is it wise / possible to use multithreading to handle control system on robot?
For example, a line follower robot with PID control flowchart would be:
read_sensor() -> calculate_control() -> ...
0
votes
0answers
78 views
Why am I unable to tune the PID parameters on my quadcopter?
I am building a nano quadcopter in X-Configuration with coreless DC motors, 65mm 2 blade propellers and a 1S Lipo battery (860mAh, 25C). The weight of the assembly is around 70g in total.
I am ...
2
votes
1answer
49 views
Control loop in or outside of main loop
I've been working on some small projects for fun to learn more control theory things and embedded programming. Thank the esp32 and Arduino!
Either way I've been programming everything entirely in a ...
1
vote
0answers
50 views
Is it possible to make a self balancing robot using small or medium scale integrated circuits?
Almost all the information I've seen about self-balancing robots implies the use of an Arduino to implement the control. I'm wondering if it is possible to implement the control using just small or ...
3
votes
1answer
83 views
Inverted pendulum controller
I had an exam yesterday, and I was asked the following question:
Why PID controller is necessary for stabilizing the inverted pendulum on a cart, why not we just use PI or PD?
Now I've seen some ...
0
votes
1answer
28 views
What is the Control mixer block that is usually found in control schemes?
There is usually a control mixer block in control schemes in robotics. What is it and what is the functionality and where can I read more about it.
Reference to the paper: https://giuseppesilano.net/...
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0answers
62 views
Compensator design
I got a plant $G(s)=\left(0.13s+1\right)/s^2$ to design a compensator which provides below demands:
Settling time : max 2s
Overshoot : max %35
Gain margin : min 10 dB
Phase margin : min 30 deg
...
0
votes
0answers
10 views
How does TTS TacTile Code Reader work?
This is the TTS TacTile Code Reader:
https://www.tts-international.com/tactile-code-reader/1010494.html?cgid=Primary-Computing_--_ICT-Bee-Bot_Blue-Bot_--_Pro-Bot
There aren't any connection pins, I ...
0
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0answers
54 views
feedback linearization for a quadrotor
I am trying to develop a controller for a quadrotor using dynamic feedback linearization technique, but I am not sure I am doing thigs correctly. I know that for designing such controller I have to ...
2
votes
3answers
114 views
How to control the velocity of a mobile robot?
I have a differential drive robot whose linear velocity and angular velocity is to be controlled. The current strategy for doing that is:
A high level path tracking module spits out the reference ...
1
vote
0answers
50 views
Partial CoM, the velocity Jacobian and Control
New to robotic arms here.
I am currently working with a 6-DOF robotic arm shown below:
I have derived the FWD Kinematics and mapped the joint angles and the resulting end-effector positions. When I ...
2
votes
0answers
35 views
value of $\gamma$ in the H-infinity norm
Suppose I have the system:
$\dot{x} = Ax+Bu$
$y=Cx+Du$
and the following Hamiltonian matrix:
$H=\begin{pmatrix}
A & \frac{1}{2}B^TB\\
-CC^T&-A
\end{pmatrix}$
I want to find the value ...
1
vote
0answers
38 views
Finding transfer function from bode plot
I try to estimate a system transfer function by hand calculation from a bode plot data but I could not succeed yet and I need someone help.
it will be appreciated if anyone explains or refer me to a ...
1
vote
2answers
46 views
Block algebra and normal algebra inconsistent
I've been playing around with some block maths, mostly trying to remember how it actually works, and I've come to a simple example that should be reduced, however when doing the normal maths, compared ...
0
votes
2answers
52 views
Why would I use three state variables for a second order system? [state space modeling]
I'm currently being asked to write a state space model of a falling object (equation attached).
I had taken a linear systems course five years ago in which I did a lot of conversion between high ...
2
votes
1answer
27 views
Constant Offset matrix
I've been reading about controlling systems via momentum wheels.
Such as in Satellites, or fancy inverse pendulums.
In a particular paper, the writer tries to explain away an offset and settling of ...
0
votes
1answer
26 views
Autonomous quadcopter: How to transform setpoint into motor inputs?
I would like to know how to transform a setpoint to inputs for the motors of a quadcopter. I would like a function like that:
...
0
votes
1answer
157 views
teleop_twist_joy with Logitech F710 Joystick force feedback error
I am using a Logitech F710 joystick game controller in ROS Kinetic Kame. I was able to perform jstest testing, and can see my joystick works well.
But when I try ...
0
votes
0answers
32 views
Relation between PWM frequency and torque
I am using Pololu G2 18v15 to drive a maxon motor. The motor is supposed to drive a load in a sinusoidal trajectory against gravity with maximum torque of 0.0634 NM with max speed of 5 rpm.
I am using ...
2
votes
2answers
92 views
Why is behavior-based robotics not as popular as deep learning or reinforcement learning?
I am a master student in Germany and one of our professors is doing robotics research but with a different paradigm - the behavior-based robotics based on Subsumption Architecture developed by prof. ...
0
votes
1answer
40 views
For what step disturbance value the system will become unstable?
I am new to control theory and have difficulties about this question
R is the input, Td is the disturbance, C is the output
Given that G1=K/(s^2+A*s), where K is the gain and A is a parameter greater ...
0
votes
0answers
20 views
How to make x variable change each time and read its value from txt file
I am working on my undergraduate project and this is my first time in using use python to control parrot bebop 2 drone and use BCI or BMI technology.
I have x variable (int) and I want to read its ...
0
votes
1answer
28 views
Do I have to use the CAN protocol that the motor controller uses in order to communicate with it?
I have a question about using the CAN bus to control motor controllers. Do I have to use the CAN protocol that the motor controller uses, e.g. CANopen CiA DS 301 CiA profile 402, in order to ...
0
votes
1answer
38 views
Fuzzy logic controller for controlling a four-bar linkage
I am trying to design a control system to move a joint of four bar linkage according to desired trajectory. A dc-motor is used to move the joint.
Can fuzzy logic controller be used to solve this ...
0
votes
3answers
62 views
Simple explanation of PID control [duplicate]
I tried reading and searching different books and links for understanding PID control but not much progress
Can some one please give me simple explanation of PID control?or atleast links where easy ...
1
vote
3answers
184 views
Control VS artificial intelligence?
I have heard of both the terms AI (artificial intelligence) based robots and control based robots.
Although they are both different fields, what is the difference between AI and control in regards to ...
1
vote
1answer
23 views
Max motor voltage for RoboClaw controller
The RoboClaw data sheet from ServoCity mentions various current limits, but what about voltage? Can I run a 110 Vdc treadmill motor?
1
vote
1answer
36 views
Sampling time selection
I'm trying to design a compensator for a pendulum type plant with arduino mega. As you can see from the picture, the system bandwidth is 9 rad/sec.
I calculated the sampling time as ws=10*wb=90, so, ...
3
votes
1answer
44 views
PID control: zero out integral on error sign change?
I am learning about PID as a novice to robotics (background in software engineering).
One common problem with PID is that if the PV is below the SP for a long time, integral term will accumulate a ...
0
votes
0answers
109 views
moveit! trajectory execution aborted
I'm trying to send a custom arm to a pose through moveit_commander_cmdline.py, it fails after sending to the said pose using " go default_pose" and returns an error.
...
1
vote
1answer
33 views
Joint torque sensor vs end-effector force sensor
I am trying to understand the difference between joint torque sensors, and force sensors, in a robot arm. From what I understand, joint torque sensors estimate the torque at each joint, whereas a ...
1
vote
1answer
25 views
Transform this matrix of distances into a more general one
I need to make the navigation and guidance of a vehicle (a quadcopter) in a platform. This platform can be seen like this:
where the blue dots are the center of each square, and the $x$ distances are ...
0
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0answers
40 views
Force Controller for robotic manipulation
I want to implement a force controller but I don't understand some concepts here.
I saw some books that say the output torque command of the force controller and the impedance controller will be ...
0
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0answers
17 views
Trajectory tracking problem for non-holonomic mobile robots
Currently, I am working on the trajectory tracking problems of autonomous ground vehicle and a little confused about the applicability of control theory for different types of wheeled mobile robots.
...
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vote
2answers
61 views
Which controller (PI or PD) is generally more robust to noisy sensor measurements and why?
Assuming no filter is used to measure error (or rate of change in error) with respect to a desired state, would a PI controller more/less/about equally robust to signal input noise compared to a PD ...
0
votes
1answer
49 views
PID control loop and feedback acquisition synchronization
In many real-time PID control loop application I have seen that the control loop is triggered exactly as the ADC interrupts arrives in order to achieve maximum synchronization between feedback ...
2
votes
1answer
38 views
When are non-diagonal matrices advantageous for linear quadratic regulators?
When setting up an optimal control problem using a linear quadratic regulator, one often chooses semi-definite matrices Q and R such that the objective function J has the form
$$J=\int_{t_0}^{t_f}(...
