Specific aspects of active and semi-active suspensions

Abstract

Abstract. This paper is concerned with the needs and possibilities of implementing the active and semi-active suspensions for wheeled vehicles of the Army of the Czech Republic (ACR) -for drivetrain configuration 4x4 to 8x8. The computer technology is currently on a very high level, the amount of data computed per second is on steep rise and various processes have a capability to be driven almost real-time. The active suspension is nowadays fully implemented in the highest classes of civil cars, therefore, it is time for the implementation into the demands for modernisation of the wheeled vehicles of ACR. The land relief of central Europe is significantly mountainous, thus the demands for the wheeled vehicles, in terms of overcoming obstacles, are very high. After the application of the active suspension, the mobility and driving comfort of the vehicle are greatly enhanced. Unfortunately, at the cost of increased energy consumption. Therefore, the amount of energy available for the drivetrain is significantly lowered. On the other hand, the amount of energy required by the semi-active suspension is remarkably lower. The mobility and driving comfort are better than a passive suspension. Thus, it is recommendable to use scanning of the land relief in front of the vehicle subsequently controlling the chosen elements of the suspension by suitable algorithms. The aim of this study is to create an analysis of accessible information about the applications and control methods of active and semi-active suspensions. Evaluation of the wide range of possibilities was done with regard to the crew of the vehicle. The crew is facing problems from the fatigue and incidence of motion sickness to the worst case scenario, failure of organs.

At the boundary of school: Continuity and discontinuity in learning across contexts

“…Overall, the various characterizations in the literature show how school contexts are typically highly regulated learning environments; in contrast, out-of-school contexts seem to allow for more time and space for students' personal interests. Nonetheless, several studies describe school contexts that allow for flexibility and adaptability (e.g., Maloch, 2005;Skerrett, 2010) and, vice versa, out-of school contexts may turn out to be highly regulated learning environments (e.g., Hock, Pulvers, Deshler, & Schumaker, 2001;James-Burdumy, Dynarski, & Deke, 2007;Tucker, Chennault, Brady, & Fraser, 1995). The reviewed studies also reflect local and situational differences between what various actors, such as students and teachers, each considered to be the school or out-of-school context.…”