×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Linear Motion and Control

Linear Motion and Control

Linear Motion and Control

(OP)
I am looking for a unique piece of hardware.  It needs to provide controlled resistance to linear motion in one direction and linear motion in the other direction.  It needs to be able to resist roughly 500lbs and move 50lbs.  It needs to be able to move/resist at about 1 ft/sec.  I need to be able to modulate the level of resistance through the motion.  It also needs to be able to measure the amount of force being applied to it at each point through the motion.

I know that hydraulics would work great for this but we are steering away from that because of the mess.  Pneumaics aren't an option because the system would be spongy.

Since the system is always pulling or resisting pulling, the force could be transferred by a cable.

RE: Linear Motion and Control

What kind of gizmo are you looking for?  One option to consider:  You might be able to apply an AC induction  gearmotor + inverter drive + encoder to provide the torque necessary to resist the force and drive at the speeds you want.  The resistive force would probably force the motor into the regenerative operation mode, so you'd need regen resistors to convert the regen voltage to heat.

This scheme could be used for rack & pinion, timing belts, ball screws, etc.

TygerDawg

RE: Linear Motion and Control

Sounds like a perfect application for a ball screw drive.

RE: Linear Motion and Control

see if this helps.

Have a leniar piston which pushes with a constant force and free slide on the back stroke. This way you can push 50lbs. For resisting use a damper (one way damper). you can adjust the damper such that u get 500lbs of resisting force with 1ft/s.

but the damper works of fluid for resistanc.

RE: Linear Motion and Control

Here is one of many types of rodless or belt cylinders that we used all over the place. Like I stated this one of many types that we used, some were used of tables for very high speed machines were accurate and stationary position was a requirement.

http://www.isotechinc.com/prod13.htm

RE: Linear Motion and Control

Pneumatics with hydraulic speed control can produce very controlable motion. Much cleaner than hydraulics on its own since the hydraylic circuit is closed. Festo used to have such a system, PHD also.

RE: Linear Motion and Control

I would suggest a brushless PM servo motor and PWM amplifier. The mechanics would be a gear box (perhaps a cyclo-converter) followed by, say, a cable reel if the stroke is long.

The speed of the servo can be continously set by a speed command.  The amount of torque can be continously set by varying the current limuit in the amplifier.  The amount of torque can be monitored by looking at the current sense output of the amplifier.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources