PID controller for Lynx robot arms

[patti482]

I am considering purchasing a Lynx robot arm for a research project. This project requires that I use a PID controller in which I can modify the proportional, integration, and derivative gains.

Do any of the Lynx robot arms come with an installed PID controller. If so, can I change the gains using a Python program?
If they do not come with installed PID controllers, can I install a PID controller either in software or hardware?

[cbenson]

@patti482 Welcome to the RobotShop Commnuity.

Lynxmotion SES V1 Robotic Arms (AL5A, AL5B, AL5D)
These use Hitec RC servos which simply move at full speed to the position they are commanded to go. The SSC-32U servo controller takes the last position request and the new one and is able to dens intermediate positions to accommodate for speed and time of the moves. Unfortunately no PID here.

Lynxmotion SES V2 Robotic Arms (4DoF and 3DoF)
These use smart servos which can be set to either mode 0 or mode 1. There is a command which allows you to send the raw duty cycle to the motor, and another to read the actual position. You can use these to develop an external PID for each servo (ex. in your choice of software installed on the computer and sent via USB to the LSS Adapter). Unfortunately there is no PID algorithm which users can modify either within or external to the servos where you can simply modify these values. Several other members here have done exactly this.

Speed control of a LSS servo motor using a Raspberry

@derbel199 Welcome to the RobotShop Community! Spotted your ticket and noticed you had posted here as well. You are correct that the Python library does not include that functionality. However, the LSS communication protocol is meant to be human readable and as such, you can send serial commands to the servo via Python fairly easily provided you have the right COM port, Baud rate and command structure. You can read more about the protocol here: https://wiki.lynxmotion.com/info/wiki/lynxmotion/vi…

High torque smart servo (HT1) parameters

I need to know the smart servo motor (HT1) parameters ( the internal resistance and inductance and the inertia)

Apply the PID with this configuration without adding a sensor

I bought a robot by lynxmotion smart servo and I will communicate by the LSS configuration software - Configure IDs in this case, can I apply the PID with this configuration without adding a sensor? how can we do it or send me the code we use arduino. Thank you and best wishes.

LSS motor velocity control

Hi, I have 4 lynxmotion lss arms that I want to control using velocity inputs. That is, my kinematic controller generates velocities which guides the end effector on a given path. I’ve been sending commands (e.g. “#1D0SD40”) to make the motors move to a given position with a given speed. However, I noted that the arm often shows jittery motion and does not move smoothly. I’ve checked my input velocities and noted that those velocities are gradually changing (i.e. no sudden large changes for the…

… and others

[scharette]

@patti482

This project requires that I use a PID controller in which I can modify the proportional, integration, and derivative gains.

Well, I think your simplest solution here is to make your own PID controller and send the resulting motion request to whatever hardware you are trying to control. It seems that’s what most robotic projects do.