Dynamics of Pneumatic Drive. Lecture Cycle. The Influence of the Adopted Friction Model on the Stability of the Transient Processes of the Servo Pneumatic Drive

Abstract

The paper considers the main features of the servo pneumatic actuator with throttle control, the design features of the drive and the element for its control are given. Two design schemes of the pneumatic drive are described and are given: an “integrated” scheme and a “spaced” scheme. The advantages and disadvantages of each of the schemes are determined. The principle of operation of each element of a servo pneumatic drive consisting of a pneumatic cylinder with feedback, a feedback sensor (position), pro-portional to the distributor is considered. The characteristic of the transition process and the criteria for estimating the transition process is given, and the static characteristic of the throttle control pneumatic actuator obtained by experimentally is given. A mathematical model of the servo pneumatic drive is given. The equations describe to unambiguously establish the connection between the desired physical quantities: the pressure level in the pneumatic cylinder cavities and the developed force of te pneumatic servo drive. The paper generates the classification of the friction models currently used to study the dynamic characteristics of the developed drives. The equations of each of the considered friction models are given. An example of constructing a friction model using a flowchart method, where connection between blocks in the diagram is real physical quantities. The charts obtained as a result of mathematical modeling of transient processes and their quality indicators for the servo pneumatic actuator, applying different contemplated friction models. An assessment of the quality of transient processes received, their analysis and the effect of the considered friction models on the stability of the drive operation. The scientific novelty of the work includes the formulation of the task of studying the sustainability of the work of the servo pneumatic actuator under different types of friction models, as well as the provision of practical recommendations to specialists engaged in the development of esign of servo pneumatic actuators and their operation. In addition, this work is based and is implemented as a course of lectures of the “Dynamics of the Pneumatic Drive”, is red by the author in MSTU named after N. E. Bauman at the department “Hydromechanics, hydromachins and hydropneumoautomatics” (E10), as part of the training of masters in the specialty 05.04.13 – hydraulic machines and hydropneumatic drives.