Determination of first and second order instant screw parameters from landmark trajectories

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Least squares methods were developed to determine instant screw axis (ISA) and angular acceleration axis (AAA) parameters in experimental and analytical studies. The algorithms provide linear relationships for rigid body velocity and acceleration descriptors based on position, velocity, and acceleration data for individual points on the body. Weighted least squares estimators are presented for statistical weighting of individual landmarks as well as for variance weighting to reduce systematic measurement effects. The methods include instantaneous second order screw motion which describes differential geometry of screw axodes. Two spatial mechanism examples provide recommendations for landmark count, distribution and placement.

Original languageEnglish (US)
Title of host publicationMechanism Synthesis and Analysis
EditorsM. McCarthy, S. Derby, A. Pisano
PublisherPubl by ASME
Number of pages9
Publication statusPublished - 1990
Event21st Biennial Mechanism Conference - Chicago, IL, USA
Duration: Sep 16 1990Sep 19 1990


Other21st Biennial Mechanism Conference
CityChicago, IL, USA


All Science Journal Classification (ASJC) codes

  • Engineering(all)

Cite this

Sommer, III, H. J. (1990). Determination of first and second order instant screw parameters from landmark trajectories. In M. McCarthy, S. Derby, & A. Pisano (Eds.), Mechanism Synthesis and Analysis (Vol. 25, pp. 429-437). Publ by ASME.