In this paper, an adaptive neural asymptotic tracking control scheme with the event-triggered mechanism is presented for a quarter-car active suspension system (ASS) with unknown road inputs and input saturation. In the control design, an auxiliary system is constructed to compensate for the input saturation of the actuator, and a linear filter is introduced to solve the chattering problem of the suspension system under the zero dynamics. By integrating integral-bounded functions into the adaptive law and control law, asymptotic convergence of the tracking error is achieved with high precision. Using the adaptive backstepping control method and introducing the command filter, an event-triggered adaptive neural asymptotic tracking control algorithm is developed, in which the radial basis function neural networks (RBFNNs) are used to approximate the unknown model dynamics. Considering the waste of communication resources in the controller, the event-triggered control (ETC) law in the controller-to-actuator channel is designed. Benefiting from the minimal learning parameters (MLP) technique, the proposed scheme requires updating only one parameter, which reduces computational complexity and saves communication resources. By using the Lyapunov’s method and the Barbalat’s lemma, the asymptotic stability of the closed-loop system is proved, and the constraint conditions for vehicle ride comfort are also guaranteed. Finally, the effectiveness of the proposed method is further verified through simulations and experimental results.

Compliant revolute joints (CRJs) offer advantages in terms of frictionless motion, compactness, and monolithic fabrication, but their practical application is often constrained by an inherent stiffness–flexibility trade-off. High rotational compliance is typically accompanied by insufficient resistance to off-axis deformation, leading to parasitic motion and reduced directional stability. To address this challenge, this study proposes a hybrid CRJ designed to enhance directional stiffness while maintaining large elastic rotational capability. The joint integrates stiff polylactic acid (PLA) reinforcement ribs within a compliant thermoplastic polyurethane (TPU) matrix, with material distribution strategically tailored to suppress off-axis deformation without compromising the intended rotational motion. The design is compatible with monolithic fabrication via dual-material fused deposition modelling (FDM). Finite element analysis, informed by experimentally characterised material and interfacial properties, is employed to evaluate the mechanical performance of the proposed joint. The results demonstrate that the hybrid joint exhibits a significantly higher ratio of off-axis to on-axis rotational stiffness compared with mono-material PLA and TPU joints, indicating effective suppression of parasitic deformation while preserving rotational compliance.

Ceramic materials are indispensable in aerospace, energy, and biomedical fields due to their high hardness, heat resistance, and corrosion resistance. However, their inherent brittleness makes it difficult to fabricate complex structures via traditional forming methods. 3D printing provides an effective near-net-shape route, among which Polymer-Derived Ceramics (PDCs) have become a research hotspot owing to binder-free composition, molecular design flexibility, and low-temperature sinterability. This review focuses on photopolymerisation-extrusion coupled moulding as a core strategy to resolve the long-standing trade-off between high precision and low defects in PDC 3D printing. We systematically review the material systems of ceramic precursors, analyze the principles of photopolymerisation-based printing for PDCs, clarify the reaction mechanisms, volumetric shrinkage mechanisms, and extrusion flow behaviors of photopolymerisation-assisted extrusion 3D printing. Emphasis is placed on how coupling mitigates contradictions between precision and defects, improves interlayer bonding, and reduces warpage and cracking. Finally, we summarize key bottlenecks and propose targeted future development directions, providing a clear reference for advancing high-performance ceramic precursor additive manufacturing.