checkfourbarcouplerlength

by Tim C. Lueth, SG-Lib Toolbox: SolidGeometry 5.6 - 4Bar/Linkages
Introduced first in SolidGeometry 4.4, Creation date: 2019-01-13, Last change: 2025-09-14

checks the solutions of invkinplan2 for a fourbar linkage calculation

Description

for some unexpected and unclear reasons, the inverse kinematic equations have some numerical instability. This function was implemented and is used within invkinplan2 to warn if the calculations contains numerical errors.

See Also: invkinplan2 , isincirclesegment

Example Illustration

 missing image of checkfourbarcouplerlength(B1,B2,PL,l2chk,tol)

Syntax

[ok,ind1,ind2,err,r1,r2]=checkfourbarcouplerlength(B1,B2,PL,[l2chk,tol])

Input Parameter

B1: REAL Solutions of joint 1 configuration ellbow down
B2: REAL Solutions of joint 1 configuration ellbow up
PL: REAL Point list for TCP
l2chk: expected length of link 2
tol: tolerance default is 1e-7 , i.e. eps2

Output Parameter

ok: true of there is no problem
ind1: index of B1 with problem
ind2: index of B2 with problem
err: maximum accoured error
r1: average link length l2 for configuration ellbow down
r2: average link length l2 for configuration ellbow up

Examples


[~,~,B1,B2,rs,PL]=invkinplan2(70,40,[40 -110 0 120]); B1=B1(rs,:); B2=B2(rs,:); PL=PL(rs,:); checkfourbarcouplerlength(B1,B2,PL,40)




Copyright 2019-2025 Tim C. Lueth. All rights reserved. The code is the property of Tim C. Lueth and may not be redistributed or modified without explicit written permission. This software may be used free of charge for academic research and teaching purposes only. Commercial use, redistribution, modification, or reverse engineering is strictly prohibited. Access to source code is restricted and granted only under specific agreements. For licensing inquiries or commercial use, please contact: Tim C. Lueth

Last html export of this page out of FM database by TL: 2025-09-21