Abstract Conventional EPS (Electric Power Steering) systems are operated by one type of steering tuning map set by steering test drivers before being released to customers. That is, the steering efforts can't change in many different driving conditions such as road conditions (low mu, high mu and unpaved roads) or some specific driving conditions (sudden stopping, entering into EPS failure modes and full accelerating). Those conditions can't give drivers consistent steering efforts. This paper approached the new concept technology detecting those conditions by using vehicle and EPS sensors such as tire wheel speeds, vehicle speed, steering angle, steering torque, steering speed and so on. After detecting those conditions and judging what the best steering efforts for safe vehicle driving are, EPS systems automatically can be changed with the steering friction level and selection of steering optimized mapping on several conditions. 1. Introduction EPS systems were developed more than 10 years ago. Now, these systems are not just only for the steering system, but also for cooperation systems with the safety functions’ systems, such as LKAS (Lane Keeping Assist System), SPAS (Smart Parking Assist System) and so on. However, those functions are not based on the steering efforts’ issues. Therefore, this paper represents active EPS systems depending on the special road conditions such as wet roads or snowy roads and emergency conditions such as steering EPS fail-safety mode or Vehicle Stability Management (VSM)-on mode. Only by using EPS sensors’ signals and the tire wheel speed sensor signal, there will be advanced algorithm logics to detect and distinguish the road conditions and emergency situations. After detecting those conditions in real time, EPS systems will support better and differentiated steering efforts with optimizing steering system friction level and steering mapping.2. Design Concept This chapter shows the concept of this EPS new algorithm. The study focused on some special driving conditions: 1) road conditions: normal roads like pavement and cement road, low mu roads like rain water roads, snowy roads, unpaved roads like countryside roads with gravel or sand and so on. 2) Vehicle driving conditions: quick accelerating and quick braking. 3) EPS failure- safety modes: Depending on the hazard severity of EPS failure, these modes would be entered into 3 different modes according to the severity of hazard: A, B and C. (A is the severest, B is severer than C) 4) VSM monitoring situation mode: Those conditions are distinguished by using EPS sensors’ signals, tire wheel speed sensor signal, VSM operating signals and so on. Depending on several conditions, the steering efforts will optimize with several cases. Figure 1 shows how steering system operates on some cases. For example, when drivers go on an unpaved road, kick back forces come to steering devices because of uneven road surfaces. In that case, if the new concept technology can give higher friction on the steering system, there can be better steering efforts and more a robust system against the rattling noise. Figure 1. Function targeting operation in some events Figure 2 shows this active steering system algorithm in EPS with several signals.Study of Active Steering Algorithm Logic in EPS Systems by Detecting Vehicle Driving Conditions2017-01-1481 Published 03/28/2017 Kyung-bok Lee, Sanghyuk Lee, Namyoung Kim, Bong Soo Kim, and Tae soo Chi Hyundai Motor Company Do young Kim Hyundai Mobis Company CITATION: Lee, K., Lee, S., Kim, N., Kim, B. et al., "Study of Active Steering Algorithm Logic in EPS Systems by Detecting Vehicle Driving Conditions," SAE Technical Paper 2017-01-1481, 2017, doi:10.4271/2017-01-1481. Copyright © 2017 SAE InternationalDownloaded from SAE International by University of New South Wales, Sunday, August 19, 2018Figure 2. Active Steering Algorithm in an EPS system As shown in Figure 3 and 4 , there are the activ