Scientists of the Institute for Problems in Mechanical Engineering of the Russian Academy of Sciences and their colleagues have created a model with a control system which will make flight simulators more realistic.

The scientists compared the proposed model with analogues used in simulators of the Russian company Tranzas, and found out that the new system allows you to control the pistons which are responsible for the movement of the simulator cabin in wider conditions, up to three times faster and one and a half times more accurately. The results of the study, supported by a grant from the Russian Science Foundation (RSF), are published in the journal Control Engineering Practice.

Devices called simulators are used to train drivers or pilots to control a car or an airplane properly. Usually it looks like a cabin mounted on a Stewart platform — a device with six independent «legs» attached at three points at the bottom and at the top of the platform. The lengths of these «legs» can be changed with the help of actuators which allow you to control the orientation of the platform. Such a movement can simulate the tilt of an airplane, when maneuvering, or the movement of a car on an uneven surface.

To make such simulators as realistic as possible, it is necessary to ensure instant and accurate tracking of computer commands with the help of the actuators. Currently, existing devices do not always respond to signals as quickly as they do in real cars or airplanes, which are affected by the environment (weather, road conditions and other factors). In addition, there are cases of failure of simulators due to overloads and incorrect operation of the control system, which can lead to unsafe operation.

To eliminate these shortcomings, the scientists have carefully studied the dynamics of the pneumatic actuators of the Stewart platform. The analysis allowed the researchers to determine the motion parameters which are to be taken into account when developing platform control systems. In particular, the diameter and mass of the pistons, the length of the actuator stem and the pressure created by the load on the elements were taken into account. Based on these characteristics, the researchers have developed algorithms that ensure high speed and accuracy of Stewart platform motion control.

«From the cabin in which a person is sitting, a signal is sent to the platform that it should make some kind of movement, for example, to bend over when the steering wheel is turned. To be more precise, this signal is sent to a digital regulator — a device connected to the pistons and „deciding“ how to change the pressure in them so that the system should provide the necessary angular and spatial movement of the platform. The mathematical model proposed by us makes it possible to make such „decision-making“ by the regulator (or „control system“) more accurate, faster and less resource-intensive than the previously existing ones», tells Nikolay Kuznetsov, the project manager, Doctor of Physical and Mathematical Sciences, RAS Corresponding Member, Head of the Leading School of the Russian Federation in the field of mathematics and mechanics, Head of the Department of Applied Cybernetics of St. Petersburg State University, Head of the Laboratory of Information and Control Systems of IPMash RAS.

The system developed by the authors will also make auto and flight simulators safer, since in addition to the characteristics affecting the movement of the pistons, the mathematical algorithm contains data on the maximum load that they are able to withstand. This will prevent the possibility of overloads, due to which the simulator may stop working or even break down.

In the future, the scientists plan, in cooperation with engineers, to implement the proposed model in real simulators in order to test their development result.