This paper propose a dynamic model of an electropneumatic clutch actuator system for heavy duty trucks. The focus is set on modeling of the clutch load characteristic which should be parameter affine, and the main purpose of the modeling task in this paper is to prepare for on-line adaption of this load characteristics. The knowledge of the clutch load characteristic is important for being able...

The CompActTM actuator features a clutch mechanism placed in parallel with its passive series elastic transmission element and can therefore benefit from the advantages of both series elastic actuators (SEA) and rigid actuators. The actuator is capable of effectively managing the storage and release of the potential energy of the compliant element by the appropriate control of the clutch subsys...

age at first breeding on Ural owl lifetime reproductive success and fitness under cyclic food conditions. – Journal of Animal Ecology 67: 359–369. survival in a variable environment: Ural owls and the three-year vole cycle. – Auk in press. effort and reproductive values in periodic environments. – seasonal recruitment and the evolution of the seasonal decline in Ural owl clutch size. – Manuscri...

This paper proposes a nonlinear observer for an electropneumatic clutch actuator. Parameter estimation of the clutch load characteristic and friction are also treated through adaptation. Estimates of piston velocity, chamber pressures and dynamic friction state are made based on piston position measurement only. Persistence of excitation conditions for convergence of the estimation error are de...

In automotive dry clutch systems the cushion spring plays an important role in terms of gradually torque transmitted during the engagement phase. In fact, it strongly influences the clutch torque transmission from engine to driveline through its non-linear loaddeflection curve. Therefore, to improve the gearshift performance in automated manual transmission is fundamental the knowledge of the c...

Owing to the high power requirements of tractors, their low-power transmission gears often experience durability problems such as burning of the clutch. The operation of tractors under high load conditions also causes clutch slip, with the consequent longer operation duration exacerbating the burning of the friction plate. Solving this problem requires effective lubricant distribution. This was...

Forest fragmentation results in population declines and extinctions for many forest vertebrates, but little is known about the mechanisms causing declines in fragments. We investigated potential causes of declines in forest fragments for an Amazonian forest frog (Colostethus stepheni) at an experimental fragmentation study site in central Amazonian Brazil using field estimates of abundance and ...

Understanding the size of clutches produced by only one parent may require a game-theoretic approach: clutch size may affect offspring fitness in terms of future competitive ability. If larger clutches generate smaller offspring and larger adults are more successful in acquiring and retaining resources, clutch size optima should be reduced when the probability of future competitive encounters i...