RSSR linkage
RSSR linkage
(OP)
need help with the math for analysizing the postion of a RSSR linkage, say giving the input angle of one of the R joint and and output of the second R joint. I have a method using rotation matrices, but this function is very computer intensive and takes awhile to calculate. Any help would be greatly appreciated. Never taken a statics or dynamics class, but not totally ignorant of the subject.





RE: RSSR linkage
Whats an RSSR linkage? and can you give details of length of links, forces etc and what exactly are you trying to workout is it just a position or velocities, acceleration.
regards desertfox
RE: RSSR linkage
RE: RSSR linkage
Anyway as described RSSR has one undefined degree of freedom, the spin axis of the spindle. You'd have to use RSRR.
If the entire frame lies in one plane with normal R axes then it can be analysed by any of the wishbone analysis programs mentioned in the suspension FAQ.
Adding the toe link complicates things, Racing by Numbers or Wishbone.bas will still handle it, I think. If you do have a single plane for the wishbones then it is easy to work out the steer effect of the toe link, by hand or graphical construction.
Cheers
Greg Locock
RE: RSSR linkage
Struggling to find anything to help sorry.
I have found a lot of sites which give analysis to four bar linkage mechanisms but these are planar.
You might have better luck if you post this in Automotive
Suspension engineering.
regards desertfox
RE: RSSR linkage
RE: RSSR linkage
Cheers
Greg Locock
RE: RSSR linkage
If you have the kinematic equations that describe this linkage and solving them is your problem then I'd suggest TK Solver. Frankly, anyone involved in technical calculations should have this software.
If your issue is coming up with the kinematic equations then I'd suggest you research areas of robotics. These types of linkages, but more importantly dealing with their math, is very common to robotics. It's been 23 years since I did this in college, but I remember we had plenty of resources for it.
By the way, what is your application. Your original post doesn't give even a hint.
- - -Dennyd, P.E.
RE: RSSR linkage
Please see the FAQ Resources for Mechanism Analysis and Synthesis (FAQ404-804). I hope this helps.
Best regards,
Matthew Ian Loew
"I don't grow up. In me is the small child of my early days" -- M.C. Escher
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: RSSR linkage
RE: RSSR linkage
Unfortunately, the terminology is fairly common, at least in the US. A conventional SLA suspension is indeed a RSSR-SS type. To steer this, the last "S" would need to be connected to a slider. I forget how that would be abbreviated. I think there are better ways of describing kinematic architectures.
Best regards,
Matthew Ian Loew
"I don't grow up. In me is the small child of my early days" -- M.C. Escher
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: RSSR linkage
RE: RSSR linkage
Greg might have a bit more confidence in his ability to do this type of analysis classically than I do in mine. I would be (and have) done this type of kinematic analysis with the help of Pro/ENGINEER. I have some similar work detailed in the thread All Wheel Steer Mechanisms (Thread60-54516) where I had a front suspension with independent suspension (2 spatial four bars) connected to a center steering mechanism (planar 4 bar) via tie-rods (2 additional spatial four bars) plus the steering input mechanism as you have (yet another spatial four bar). For the front axle system alone it was ultimately a spatial 13-bar mechanism (mobility 3). The rear twin axles were even more complicated.
Best regards,
Matthew Ian Loew
"I don't grow up. In me is the small child of my early days" -- M.C. Escher
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: RSSR linkage
Cheers
Greg Locock
RE: RSSR linkage
RE: RSSR linkage
Cheers
Greg Locock
RE: RSSR linkage