Power Requirements Research On Active Suspension System

Active suspension possesses the advantages of controlling vehicle body movement, isolating road vibration effectively, improving ride comfort and adjusting the vehicle body height. Though active suspension gets more and more attentions from the researchers, but it isn’t got wide application because of its disadvantages of complex structure, large energy dissipation and high cost. As a kind of active suspension, the slow active suspension have much smaller power requirement than other kinds of active suspension. It is necessary to study the power requirement of active suspension to overcome its disadvantages. Research on power requirement of active suspension could provide evidences for the design and wide application of active suspension.1. Based on the structure of slow active suspension system and the control algorism of linear quadratic regulator(LQR), this paper builds the slow active suspension model and full active suspension model, taking the full active suspension as reference, and solves the power of active suspension with the method of average power. Through simulation, it found that slow active suspension has a much smaller power consumption, poor ride comfort, but best stability than full active suspension. Comparing with passive suspension, active suspension has a great improvement in its performance.2. In order to analyze the effects of road, response frequency and structure parameters of suspension, simulation was made according to the formula of average power of slow active suspension. The simulation results show that the change of the road to the power consumption of slow active suspension is the same as the change of road power spectrum and power consumption has a linear relation with the vehicle speed. Response frequency influence to the power consumption is decided by the, where, response frequency has little effects to the power consumption under control algorithm of LQR. The structure parameters include the damping and suspension stiffness. The damping effects on the power consumption present a quadratic function curvilinear relationship while the suspension stiffness has little effects on the power consumption of slow active suspension. The analysis of influence factors on the power consumption of slow active suspension provides reference basis for the design of suspension system, which made the designed slow active suspension with a good performance and little power consumption.3. Currently, the existing evaluation methodology of suspension system is mostly used to evaluate the performance of suspension without considering the power consumption of suspension system. Aiming at the deficiency of suspension evaluation system, the concept of suspension efficiency is raised to evaluate the power consumption of suspension on whole vehicle. Meanwhile, the concepts of ride efficacy and stability efficacy are put forward to evaluate the comprehensive performance of suspension system which including ride comfort, stability and power consumption. The larger of the values of ride efficacy and stability efficacy, the comprehensive performance of suspension system is better.