The work presents the analysis and synthesis of an eight-link mechanism for industrial seat suspension, followed by a numerical optimization design under specific technical requirements. Even though eight-bar linkage is well-known architecture, it has few applications in suspensions, shows interesting features compared with more traditional scissor systems. It possible to exploit this mechanism...

Many mathematical and intuitive methods for constraint analysis of mechanisms have been proposed. In this article we compare three methods. Method one is based on Grüblers equation. Method two uses an intuitive analysis method based on opening kinematic loops and evaluating the constraints at the intersection. Method three uses a flexible multibody modeling approach which facilitates the analys...

For its first release in 2004, CRANK was shown to effectively detect and phase anomalous scatterers from single-wavelength anomalous diffraction data. Since then, CRANK has been significantly improved and many more structures can be built automatically with single- or multiple-wavelength anomalous diffraction or single isomorphous replacement with anomalous scattering data. Here, the new algori...

This paper proposes an efficient exact dimensional synthesis method for finding all the link lengths of Watt II and Stephenson III six-bar slider-crank function generators, satisfying nine prescribed precision points using homotopy continuation method. The equations each mechanism are initially constructed as a system 56 quadratic polynomials whose Bézout number, which represents maximum number...

UNLABELLED Maximal cycling power has been reported to decrease more rapidly when performed with increased pedaling rates. Increasing pedaling rate imposes two constraints on the neuromuscular system: 1) decreased time for muscle excitation and relaxation and 2) increased muscle shortening velocity. Using two crank lengths allows the effects of time and shortening velocity to be evaluated separa...

People with amputation move asymmetrically with regard to kinematics (joint angles) and kinetics (joint forces and moments). Clinicians have traditionally sought to minimize kinematic asymmetries, assuming kinetic asymmetries would also be minimized. A cycling model evaluated locomotor asymmetries. Eight individuals with unilateral transtibial amputation pedaled with 172 mm-length crank arms on...

OBJECTIVES The limiting factors with regard to power output available for wheelchair ambulation have not been identified. The aim of the present study was to correlate power output during wheelchair driving with (i) power output and oxygen uptake during arm crank ergometry and (ii) arm muscle strength. METHODS Eleven disabled men were examined for maximal power output (POmax) during wheelchai...

Kinematic chains made from links whose lengths and twist angles satisfy a certain proportionality rule are considered. A notion of exchange symmetry for the any such chain affords new understanding mobility well-known overconstrained mechanisms, exemplified by Bennett’s four-bar linkage, provides unifying framework explaining recently discovered class nontrivial underconstrained mechanisms. The...