Key Takeaways & Executive Findings
- •• Introduces a novel four-wheel consistent coordinated steering control for 4WIS vehicles, reconfiguring Ackerman steering relationships as coupling constraints. • Utilizes constraint-following control to achieve uniform boundedness and uniform ultimate boundedness of the Ackerman steering principle constraint error. • Demonstrates through Carsim/Simulink joint simulation that the algorithm ensures approximate satisfaction of the Ackerman steering principle in both transient and steady-state path tracking. • Significantly improves path tracking performance of 4WIS vehicles, reducing tire wear and enhancing safety and efficiency.
Abstract
Research has shown that when vehicles follow the Ackerman steering principle (ASP), the tire wear can be reduced and the path tracking performance can be improved. However, in the case of four-wheel independent steering (4WIS) vehicles, the steering systems of the four wheels are relatively independent, and there are differences and uncertainties in individual steering dynamics, which lead to challenges for all four wheels in simultaneously satisfying the ASP and may deteriorate the vehicle path tracking performance. In response to this problem, this paper introduces a four-wheel consistent coordinated steering control for 4WIS vehicles. The algorithm innovatively reconfigures the Ackerman steering relationships as coupling constraints among the wheels, and utilizes the constraint-following method to design controller. The controller achieves uniform boundedness (UB) and uniform ultimate boundedness (UUB) of ASP constraint error. The Carsim/Simulink joint simulation results demonstrate that the algorithm guarantees the approximate satisfaction of ASP in both the transient and steady-state of the vehicle path tracking. Also, it significantly improves the path tracking performance.
1. Introduction
The automatic driving technology has great advantages in solving traffic problems and improving driving safety and fuel efficiency [1]. The most basic and important task of autonomous driving is to perform path tracking. Most of the past path tracking problems focus on the front-wheel steering (FWS) vehicles and have solved by linear quadratic regulator (LQR) [2], model predict control (MPC) [3–5], sliding mode control (SMC) [6, 7], and other methods [8–10]. FWS vehicles only rely on front wheels to control steering. This characteristic undoubtedly limits the steering performance. Now, four-wheel independent steering (4WIS) vehicles have gained a lot of attention due to their high flexibility. The steering system of 4WIS vehicles is essentially a redundant drive system. This allows it to realize FWS mode, four-wheel Ackerman steering mode, crab motion mode, and even zero-radius steering mode by combining different steering degrees of freedom. However, due to its inconsistencies of multiple actuators and system uncertainties, the path tracking problem of 4WIS vehicles has become a difficult point.
There are no mechanical constraints among the four wheels of 4WIS vehicles, and the path tracking is realized by the coordinated steering of four wheels. If the rear wheels are restricted from steering while the front wheels steer, the path tracking strategies of FWS vehicles are also applicable. However, these methods cannot take full advantage of 4WIS vehicles’ flexibility. There have been several studies on path tracking control considering the 4WIS vehicle characteristics, and most of them use the hierarchical architecture [11–17]. The upper layer solves for the required virtual control variables to achieve the path tracking task (such as lateral forces, steering radius and equivalent steering angle). Meanwhile, in the lower layer, the desired steering angle for each wheel is calculated based on the virtual control variables.
Loading authentic research manuscript (Pages 1–5)...
Zeyu Yang, Yusheng Dai, Manjiang Hu, Yougang Bian, Qingjia Cui, Yang Li (2025). Improving Path Tracking Performance of 4WIS Vehicles via Constraint-Oriented Consistent Coordinated Steering. Chinese Journal of Mechanical Engineering. https://doi.org/10.1186/s10033-025-01298-4
Research & Educational Purpose Only:The translations, structured abstracts, analytical annotations, and data reports provided by SinoTechIntel are intended exclusively for academic research, internal corporate R&D, and educational benchmarking. They do not constitute formal engineering, chemical safety, legal, or professional advice.
Copyright & Intellectual Property Notice: Original copyright of the underlying source articles and experimental data remains with the respective authors, institutions, and original publishing journals. SinoTechIntel claims intellectual property only over its proprietary translations, analytical syntheses, and AEO structured enhancements in accordance with international fair use and academic citation principles.
Frequently Asked Questions
What is the main contribution of this paper?
The paper introduces a four-wheel consistent coordinated steering control for 4WIS vehicles, which reconfigures the Ackerman steering relationships as coupling constraints and uses constraint-following control to ensure uniform boundedness and uniform ultimate boundedness of the constraint error, thereby improving path tracking performance.
How does the proposed method handle uncertainties in 4WIS vehicles?
The method uses constraint-following control, which is robust to system uncertainties and differences in individual steering dynamics, ensuring that all four wheels approximately satisfy the Ackerman steering principle despite these uncertainties.
What are the simulation results demonstrating the effectiveness of the algorithm?
Carsim/Simulink joint simulation results show that the algorithm guarantees approximate satisfaction of the Ackerman steering principle in both transient and steady-state path tracking, and significantly improves path tracking performance.
Why is the Ackerman steering principle important for 4WIS vehicles?
Following the Ackerman steering principle reduces tire wear and improves path tracking performance, which is crucial for the safety and efficiency of autonomous driving.
What are the potential applications of this research?
This research can be applied to autonomous vehicles, particularly those with four-wheel independent steering, to enhance their path tracking accuracy and stability, contributing to safer and more efficient autonomous driving systems.
Related Technical Papers & Translations
Direct Repair of the Crystal Structure and Coating Surface of Spent LiFePO4 Materials Enables Superfast Li-Ion Migration
The rapid accumulation of spent LiFePO4 (LFP) cathodes from retired lithium-ion batteries necessitates the development of effective and environmental-friendly recycling strategies. In this context, direct regeneration has emerged as a promising approach for reclaiming LFP cathode materials, offering a streamlined pathway to restore their electrochemical functionality. We report an integrated regeneration protocol that simultaneously repairs the degraded crystal structure and reconstructs the damaged carbon coating in spent LFP. The regenerated cathode material had superfast lithium-ion diffusion kinetics and a stable cathode–electrolyte interface, giving a remarkable rate capability with specific capacities of 122 mAh g−1 at 5C and 106 mAh g−1 at 10C (1C = 170 mA g−1). It also maintained capacities of 110.7 mAh g−1 (5C) and 84.1 mAh g−1 (10C) after 400 cycles. It could be used in harsh environments and could be stably cycled at subzero temperatures (−10 and −20 °C) and in solid-state electrolyte batteries. Life cycle assessment combined with economic evaluation using the EverBatt model reveals that this direct regeneration approach has high economic and environmental benefits.
Oxide Semiconductor for Advanced Memory Architectures: Atomic Layer Deposition, Key Requirement and Challenges
Oxide semiconductors (OSs), introduced by the Hosono group in the early 2000s, have evolved from display backplane materials to promising candidates for advanced memory and logic devices. The exceptionally low leakage current of OSs and compatibility with three-dimensional (3D) architectures have recently sparked renewed interest in their use in semiconductor applications. This review begins by exploring the unique material properties of OSs, which fundamentally originate from their distinct electronic band structure. Subsequently, we focus on atomic layer deposition (ALD), a core technique for growing excellent OS films, covering both basic and advanced processes compatible with 3D scaling. The basic surface reaction mechanisms—adsorption and reaction—and their roles in film growth are introduced. Furthermore, material design strategies, such as cation selection, crystallinity control, anion doping, and heterostructure engineering, are discussed. We also highlight challenges in memory applications, including contact resistance, hydrogen instability, and lack of p-type materials, and discuss the feasibility of ALD-grown OSs as potential solutions. Lastly, we provide an outlook on the role of ALD-grown OSs in memory technologies. This review bridges material fundamentals and device-level requirements, offering a comprehensive perspective on the potential of ALD-driven OSs for next-generation semiconductor memory devices.
Laser powder bed fusion of biodegradable Zn-4Cu alloy: Processing, microstructure and properties
Zn's natural degradability and biocompatibility make it a promising candidate for implants, however, its mechanical properties remain insufficient for bone applications. In this study, the performance of Zn was enhanced by developing Zn-Cu alloys via laser powder bed fusion (LPBF). Optimal LPBF parameters for forming stable tracks were achieved by adjusting laser power and scanning speed. Under optimized conditions of 100 W and 100 mm/s, high-density (99.58%) Zn-Cu alloys with improved hardness (68.2HV) and yield strength (160 MPa) were achieved. These improvements are attributed to solid solution strengthening, segregation strengthening, and grain refinement. The Zn-Cu alloys also demonstrated favorable degradation behavior, with a rate of 0.16 mm/year. This degradation is primarily driven by micro-galvanic corrosion between the CuZn5 phase and Zn matrix, along with refined grains and increased grain boundary density. This work demonstrates a viable strategy for fabricating Zn-based implants with enhanced structural integrity and mechanical performance via LPBF.