Smart Ball Joint: from mechanical design to semi-active suspension control

The purpose of this thesis is to design a semi-active suspension activated by a smart ball joint by exploiting the outcomes coming from vehicle dynamics analysis. The thesis is divided in six sections. The first one describes the active and semi-active suspension state of art and the reason explains the reasons why they might be useful. Next, the mechanical design stage starts by proposing a first concept of a smart ball joint, selecting its sensors, and studying the way the loads are applied. The third section is dedicated to vehicle dynamics considerations, performed by means of Adams Car multibody modelling and simulation. The results coming from standard dynamic maneuvers, such as double lane change, swept sine steer and braking simulations set the target values about the vehicle roll reduction. Hence, an Adams Car – Matlab Simulink co-simulation is carried out to have a model to build the control logic and to outlook the outcomes of its implementation with the aid of the smart ball joint semi-active damper. The last sections are dedicated instead to the smart ball joint design optimization and testing validation. In this last section, considerations about packaging, orientation and installation of the innovative ball joint are made, as well as the tests on the sensor and the whole ball joint and sensor subsystem. The results coming from the tests are the input for the semi-active suspension actuation.