Motor control

As part of my third year mechatronic project to build a one jointed robotic arm controlled by the use of finger motion i'm looking into using plc control. basically the robot arm should mimic the motion of your finger. i have researched using flex sensors which can be attached on the operators finger and the robot joint. (a flex sensor simply changes resistance as you bend the sensor) so that the plc can cmpare the resistance of each flex sensor and aplly a voltage to a geared down d.c motor ontill the two resistances of the two flex sensors matches each other. i would appreciate any help how i should set about this project

Robotic arm

Dominic, (I'm going to presume it's you Dominic,Dom 19). The first thing I want to say is how disappointed I am that you have logged onto a site like this. A pointless waste of time, any information on this site is too general to be any good for you. I already explained that the library has links to dedicated material for students such as engineering websites and journals. These feature past projects and are an invaluable source of information because it is aimed at students like yourself,a bit slow but willing to learn.The "clowns" on this site are more than likely going to give you false information purposely wasting your time because they have nothing better to do.But the bit that really ****es me off is that you never came to me about your problems. I am P.Cooke!.What do you think the "P" stands for?,that's right it stands for PLC Cooke.I have the passion that none of these pretenders have.Is it because you don't think I can handle some **** easy robotic arm? Dominic, I eat pressure and I **** results!!.So now that your set straight I'll be waiting for a knock at my door and for you to walk in,head hanging in shame begging for forgiveness from the 'special one'.If I ever catch you anywhere near this site again I'm going to stick a PLC up your hole and you'll need a robotic arm to remove it!!!

Well to start with it seems you'll require a PLC with TWO analog input channels. (maybe voltage, not current).

Maybe your going to use a PWM motor control? Do you have any information on the motor drive? Depending on the drive or how much control you want you may need either an analog output, or a counter module to output a pulse train for driveing the motor.

The program code would be rather simple. The higher the differential between the input, and feedback sensors, the faster you would go in that direction.

Direction would be established by doing a scan to scan comparision of the input value. If the input value is greater on scan 2 then it was on scan 1, then the direction would be set to Forward, and visa versa for reverse.

I am going to politely agree and disagree with p.cooke

I do not know p.cooke and from the comments have no interest in knowing him but will agree that their are ibraries/sites for engineering students that the school provides which are invaluable.

I disagree that he (or anyone one) is the "end all/know all" for plcs and/or robots. I also disagree that the members here will purposely misinform you...in many cases they will go far beyond your expectations BUT it is required that you do some work.

Personal opinion but anyone that would make this comment about me is not a person I would want as a tutor, regardless of his abilities, but sometimes you have to deal with egotistical AH's to get where you want to be.

These feature past projects and are an invaluable source of information because it is aimed at students like yourself,a bit slow but willing to learn.

Click to expand...

Another factor to consider is that the people here ARE the ones in the real world using/incorporating a wide range of devices. They may be the ones you go to for a job or work with on a job.

Dom,

I would NEVER EVER! allow myself to learn from only ONE person!
While that person MAY be correct MOST of the time that person will NOT BE CORRECT ALL THE TIME.

Widen your horizon, not just one person - and welcome to the club

I notice that PCooke has never offered any help in this 'sorry' forum. Perhaps, he is not able to.

If he gives you an 'F', tell him to take an 'F'

Rod (The CNC Dude)

PS: I only have 100+ machines running in four countries. Can the GREAT WONDEROUS BEING PCOOKE say the same?

PCOOKE, lookup Punch Wizard and see what REAL MEN do!

Alaric,
Thanks. Someday I'll learn not to get my back up.

Rod

Fred? Is that you?