An investigation on semi-active suspension damper and control strategies for vehicle ride comfort and road holding

Abstract

The real “golden age” of electronic suspension can be probably located in the 1980s; during that decade the exceptional potential of replacing a traditional spring-damper system with a fully fledged electronically controllable fast-reacting hydraulic actuator was demonstrated. High costs, significant power absorption, bulky and unreliable hydraulic systems, and uncertain management of the safety issues: the fatal attraction for fully active electronic suspensions lasted only a few years. In the second half of the 1990s, a new trend emerged: it became increasingly clear that the best compromise of cost (component cost, weight, electronics and sensors, power consumption, etc.) and performance (comfort, handling, safety) was to be found in the technology of electronically controllable suspensions: the variable-damping suspension or, in brief, the semi-active suspension. After a decade this technology is still highly promising and attractive: it has been introduced in the mass-market production of cars; it is entering the motorcycle market; a lot of special vehicles or niche applications are considering this technology; many new variable-damping technologies are being developed. Semi-active suspensions are expected to play an even more important role in the emerging trend of electric vehicles with in-wheel motors: in such a vehicle architecture the role of suspension damping is more crucial, and semi-active suspensions can significantly contribute to reduce the negative effects of the large unsprung mass. As in many other electronically controlled systems, the actuator is not “smart itself”: it simply inherits the smartness (or dumbness) of its control algorithm designer. The key of semi-active suspensions is in the algorithm. For the discussed reasons, this paper briefly reviews the basic theoretical concepts for variable-damping shock absorber technologies and the available control algorithms.

Online Adaptive Optimal Control of Vehicle Active Suspension Systems Using Single‐Network Approximate Dynamic Programming

“…Naturally, the suspension systems are then expected to have more intelligence to accommodate themselves in various road conditions. Hence, many control methods as summarized in [1] have been used for suspension controller design. However, model uncertainties due to the parameter uncertainties and unknown road inputs in real suspension systems bring a great challenge for the controller design.…”

Design of a Road Friendly SAS System for Heavy-Duty Vehicles Based on a Fuzzy-Hybrid-ADD and GH-Control Strategy

“…It has been verified by many studies as a simple but effective way to reduce the SMA [3][4][5]. In addition, another effective approach for SMA control is the acceleration-driven damper (ADD) control strategy [6,7]. This approach has been proved to be the optimal one in the minimization of the SMA and also more simple in the aspect of implementation than the SH approach.…”

Adaptive Hybrid Control of Vehicle Semiactive Suspension Based on Road Profile Estimation

“…Prominent examples of such strategies include the groundhook [9,10], robust control [11], and MPC (Model Predictive Control) [12,13]. To evaluate the performance of a vehicle suspension system, three criterions are widely used [6,[14][15][16][17].…”

“…To isolate the vehicle body and passengers from road disturbances, the performance in terms of two frequency ranges needs to be improved: the natural frequency for the vehicle body (1-1.5 Hz), and the frequency range to which humans are sensitive (4-8 Hz) [18]. To simplify the calculation process, the acceleration of the sprung mass is typically used as the metric upon which comparison is based [1,4,7,[15][16][17]19].…”