This paper deals with further development of a graphical specification language resembling timing-diagrams and allowing specification of partially ordered events in input and output signals. The language specifically aims at application in modular modelling of industrial automation systems and their formal verification via model-checking. The graphical specifications are translated into a model...

Flexible pins eliminate the need for straddle mounting, and therefore enable the maximum possible number of planets to be used for any particular epicyclic ratio of power transmission systems. Having more planet gears will significantly increase the input torque density. In this type of design, the pin stiffness and position tolerances are important parameters as they affect the dynamic perform...

many studies have been done on hybrid vehicles in the past few years. the full hybrid vehicles need a large number of batteries creating up to 300 (v) to meet the required voltage of electric motor. the size and weight of the batteries cause some problems. this research investigates the mild hybrid vehicle. this vehicle includes a small electric motor and a high power internal combustion engine...

A method for the determination of the optimal polynomial functions for the conduction of machine-tool setting variations in pinion teeth finishing in order to reduce the transmission errors in spiral bevel gears is presented. Polynomial functions of order up to five are applied to conduct the variation of the cradle radial setting and of the cutting ratio in the process for pinion teeth generat...

A detailed assessment of the acoustic performance of several noise reduction concepts for aircraft flaps and landing gear is presented. Consideration is given to the best performing concepts within the suite of technologies that were evaluated in the NASA Langley Research Center 14by 22-Foot Subsonic Tunnel using an 18% scale, semi-span, high-fidelity Gulfstream aircraft model as a test bed. Mi...

In this article the description of some types of spatial gear constraints (spur gears, bevel gears, etc.) in absolute coordinates is considered. Instead of the numerical expensive calculation of constraint Jacobian matrix we propose to use the transformed Jacobian matrix, which can be calculated much more efficiently. The proposed methods of description of gear constraints were implemented for ...

A pair of DNA nanocircles has been constructed to model gears. The nanogears can move against each other continuously. Each gear consists of a DNA duplex circle and three single-stranded teeth. The teeth on the two gears are brought together by linker strands, which are complementary to the gear teeth. The teeth are separated from each other by removal of the linker strands with a strand displa...

Symbolic algebraic analysis techniques are applied to the landing gear subsystem in the new Swedish ghter aircraft, JAS 39 Gripen. Our methods are based on polyno-mials over nite elds (with Boolean algebra and propositional logic as special cases). Polynomials are used to represent the basic dynamic equations for the processes (controller and plant) as well as static properties of these. Tempor...

Primarily for aerospace applications, harmonic drives (HD’s) are high-ratio, compact torque transmission systems. This mechanical transmission employs a continuous deflection wave along a non-rigid gear, the socalled ‘flexspline’, to allow gradual engagement of gear teeth. A harmonic drive also contains a wave-generator (a ball-bearing assembly with a rigid elliptical inner-race) and a circular...