Model-Free Output Feedback Path Following Control for Autonomous Vehicle With Prescribed Performance Independent of Initial Conditions

Abstract

Time-delay control (TDC) is widely recognized as a robust and straightforward model-free control approach for complex systems. However, the transient performance and settling time are often given less consideration in most TDC-based controllers. In this article, we propose an integrated control protocol that combines fixedtime prescribed performance control with time-delay estimation techniques for autonomous ground vehicles. The proposed control paradigm offers the advantages of being model-free while ensuring that the preview error converges to a neighborhood of zero within a fixed time, adhering to predefined constraint functions. To overcome the limitations of commonly used exponential decay boundaries, a prescribed performance function that remains independent of the initial conditions is employed. Furthermore, a highorder model-free fixed-time differentiator is constructed to observe the high-order dynamics of the preview error, which are essential for estimating unknown model dynamics. Finally, the simulations and practical experiments have been conducted to demonstrate the superiority of our proposed control protocol. Index Terms-Fixed-time convergence, model free, pathfollowing control, prescribed performance control (PPC), time-delay control (TDC). NOMENCLATURE δ fFront-wheel steering angle. β/γSideslip angle/yaw rate of vehicle.

Adaptive Terminal Sliding Mode Trajectory Tracking Control for Autonomous Vehicles Considering Completely Unknown Parameters and Unknown Perturbation Conditions

“…The linear sliding mode controller still uses Formulas (34) and (35) and needs to modify which p, q values are modified to 1, and the parameter-known non-singular terminal sliding mode controller needs Formula (34) in b, Â, and dm , with the calculation of the determination of the value instead, so that b = 0.15, ÂT = [0.01 0.1], and dm = 1. The vehicle speed is 50 km/h, an ordinary asphalt pavement is selected, the pavement adhesion coefficient µ = 0.6, and the simulation results are shown in Figure 4.…”

“…The three-degrees-of-freedom four-wheel dynamics model and coordinate system are shown in Figure 1. The vehicle dynamics model is modeled as follows [33,34]. Figure 1 shows the vehicle dynamics model used in this paper, and its main parameters are shown in Table 1.…”

“…The physical parameters of the vehicle in the simulation are shown in Table 2. The parameters of the controllers (34) and (35) are selected, as shown in Table 3. The data in Table 2 represent the standard parameters of the B-class vehicle model in the CarSim platform, provided by the CarSim platform itself.…”

Terminal sliding-mode controllers with fixed-time stability and its applications to lateral control of an autonomous vehicle

“…An interesting application is in the control of lateral vehicle dynamics: in [16], a fixedtime controller was proposed for autonomous vehicles with saturated input. The lateral control of autonomous systems is a crucial component of autonomous vehicle control [17], [18]. However, designing control systems with a convergence rate for these systems is a challenging task, as indicated by the numerous publications on this topic [17], [18].…”

“…The lateral control of autonomous systems is a crucial component of autonomous vehicle control [17], [18]. However, designing control systems with a convergence rate for these systems is a challenging task, as indicated by the numerous publications on this topic [17], [18].…”