Design And Analysis Of A Mechatronic Inerter

Inerters are two-terminal mechanical devices, which can simulate large masses. Moreover, inerters correspond to capacitances completely under the force-current analogy between mechanical and electrical networks. Consequently, its appearance promotes the development of the mechanical networks synthesis theory. Traditional inerters simulate masses by flywheel energy storage, it means that the raise of inerterance leads to extraordinary increasement of the inerters' mass, which is adverse to engineering practice. To increase the ratio of the inerters' inertance to its mass(hereafter referred to as ratio), a novel mechatronic inerter is proposed in this paper, and its properties is analysed. The main works of this paper are as follows:(1) The armature circuit of DC motor is designed. By deduction, the armature circuit is designed to be a series connection of a NIC and a capacitance. The NIC offsets most of the armature resistance and armature inductance, therefore, the armature circuit presents the characteristic of capacitance, which means the mechatronic inerter simulates masses by capacitance energy storage.(2) The stability of mechatronic inerter is analysed by utilizing the Routh criteria. As a result, to make the mechatronic inerter work stably, there must be residual resistance left in the armature circuit.(3) The operating range of the mechatronic inerter is discussed. Assuming amplifiers saturation and electromagnetic induction failure as two failure conditions of armature circuit, by deduction, the frequency range and amplitude range of applied force are obtained to insure the armature circuit working normally. Moreover, the frequency range and amplitude range are related to the capacitance connected in armature circuit.(4) The circuit parameters' influence on the “force-velocity” property of the mechatronic inerter is analysed. As a result, the mechatronic inerter approximates to an ideal inerter only in 1Hz~10Hz. Moreover, the bigger the capacitance connected in armature circuit is, the narrower the bandwidth in which the mechatronic inerter approximates to an ideal inerter becomes.(5) The largest of inertance that the mechatronic inerter is able to achieve is discussed. Based on the frequency range and amplitude range of applied force obtained above, the largest capacitance that can be connected in the armature circuit is obtained. Consequently, the largest inertance that the mechatronic inerter can achieve is obtained.(6) The feasibility of the mechatronic inerter is experimentally verified. An experimental prototype of the mechatronic inerter and its testing platform are developed. By testing and comparison, the inertance of mechatronic interter is obviously larger than mechanical inerter's inerter. Moreover, with the increasement of the capacitance in armature circuit, the inertance of mechatronic inerter becomes larger.