# Technique of Calculating Positioning Errors of Motion Simulator End Member

### Аuthors

Zakharov A. G.

State Institute of Aviation Systems, 7, Victorenko str., Moscow, 125319, Russia

e-mail: 1zahar1@rambler.ru

### Abstract

Purpose
Improvement of airborne system performance inevitably leads to more stringent specification for their testing equipment, in particular, for motion simulators. At present, there is an actual task to improve the static positioning accuracy of the end member of motion simulators. In this connection, the issues related to assessment, measurement and improvement of motion simulator positioning accuracy take on great importance.
Design/methodology/approach
The paper proposes a methodology which was developed for determination of the end member positioning error in the gimbal based motion simulators that have several axes with their initial orthogonal orientation. This approach allows considering influence of the disposition error of motion simulator axes, unit under test mounting error, as well as errors caused by actuator and the measuring system.
In the framework of this technique development, the mathematical model of the end member positioning error was composed with the help of matrix methods. The author proposed a technique for determination of the mathematical model coefficients for motion simulators that have from 1 to 3 axes.
Findings
As a result of the study, a mathematical model has been developed along with software which according to the given manufacture and assembling errors of motion simulators calculates the maximum error of the end member position. The program has a practical value because it can be used while forming the requirements to the motion simulators, and when choosing optimal design solutions for the motion simulators.
Research limitations/implications
The article considers the motion simulators built on the base of gimbal mounts that have orthogonal axes orientation as a nominal case. Mathematical model doesn’t take into consideration the linear error of dynamic test bench axes position.
Originality/value
Unlike the well-known methods of determination of the motion simulator end member positioning error, the method offered allows easily automate the process of error definition for any kinematic scheme of the motion simulator gimbal mount. This property was realized in the program for calculation of the maximum control signal execution error by the motion simulator end member. This program allows calculation of errors for motion simulators having from 1 to 3 degrees of freedom with arbitrary mutual position of axes, and considers the influence of the dynamic test bench axes position errors, as well as that of a mounting error of the unit under test, and that of the errors brought into by the actuator and the measuring system.

### Keywords:

motion simulator, gimbal mount, positional error, kinematic accuracy

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