New Method for Measurement of Time Characteristics of Mechanical Systems

Abstract

It is well known that mechanical systems can be described by such characteristics as impulse response, step response, frequency response and transfer function. For instance, the suspension system in a car is described by the following transfer function $$K\left( s \right) = \frac{{1 + as}}{{1 + as + b{s^2}}},$$ (1) where the positive constants a and b depend on the elasticity, mass and damping coefficient. From (1) we can easily derive the time characteristics - impulse response and step response. Unfortunately, the equality (1) is only a model of the suspension system. This model was established under some assumptions and simplifications (sometimes very rigorous). Consequently, we cannot expect that the step response of the suspension system will be given by $${L^{ - 1}}\left( {{s^{ - 1}}K\left( s \right)} \right),$$ where L is the Laplace operator. To avoid such disadvantages we shall propose a new method for direct measurement of time charakteristics of mechanical systems.