This study presents a novel cable-driven parallel robot integrated with rigid–flexible coupling and a variable stiffness system, specifically designed to replicate the motion characteristics of the human cervical spine. Kinematic control of the robot is achieved by establishing a functional relationship between its configuration space and actuation space, where cable length variations are constrained within ±40 mm. Furthermore, this work explores static and dynamic modeling methodologies, highlighting their critical role in evaluating the robot's performance under operational poses. A detailed analysis is conducted to investigate the synergistic effects between the rigid–flexible coupling structure and the variable stiffness system. By incorporating adjustable stiffness parameters, a dynamic model is developed to reveal the robot's behavioral characteristics under different poses. Simulation results demonstrate that the robot achieves a maximum bending angle of 30° under cable tensions from 0 to 80 N, while its operational stiffness can be dynamically modulated from 3900 to 4700 N m−1 (with a tuning bandwidth of up to 100 %). These quantitative findings confirm the validity of the proposed model and illustrate the capabilities of the robot in flexible bending motion and stiffness regulation, providing a valuable reference for the design and analysis of other cable-driven flexible mechanisms.
TiZr-based high-entropy alloys (HEAs) have emerged as promising energetic structural materials (ESMs) due to their unique combination of penetration capability and impact-induced energy-release behavior. However, a comprehensive understanding of the coupled deformation, fracture, and energy-release mechanisms in HEA-based ESMs, particularly for TiZr-based systems designed to balance mechanical strength and reactivity, remains elusive. In this work, three representative TiZr-based HEAs were fabricated via vacuum arc melting. A novel three-layer spaced target structure was designed to simulate combined metal-casing and internal circuitry systems. The underlying mechanisms governing the coupled mechanical-energetic response were investigated by integrating quasi-static and dynamic mechanical testing with post-mortem microstructural characterization and energy-release quantification. The flash duration and intensity of the energy release were further proposed as optical indicators to quantitatively characterize the impact-induced energy-release behavior of TiZr-based HEAs, where flash duration reflects the sustained energy-release capability and flash intensity represents the instantaneous energy-release intensity. The results demonstrate that TiZrNbWV exhibits the highest yield strength and superior dynamic mechanical performance, together with the most persistent energy-release behavior, whereas TiZrNbV exhibits the best plastic deformation capability and a slightly higher quasi-static fracture strength, along with the stronger instantaneous energy-release capability under low-velocity impact conditions. Ballistic tests indicate that penetration of the front aluminum (Al) plate is dominated by kinetic effects, whereas significant thermochemical energy release occurs during interaction between fragmented projectiles and the rear circuit board. Increasing impact velocity promotes projectile fragmentation and oxygen-assisted oxidation, significantly enhancing the energy-release intensity and post-penetration effects. This work provides insights into the design of HEA-based ESMs with improved mechanical and energetic performance for defense and aerospace applications.
The critical challenge of excessive junction temperature caused by ultra-high heat flux densities (> 100 W cm−2) in deep-sea LED fish-attracting lamp (FAL) arrays is addressed. This study proposes a hybrid thermal management scheme integrating interfacial micro-texturing, chimney effect convection, and heat pipe phase change heat transfer, achieving the unification of passive high-efficiency heat dissipation and pressure-resistant sealing. The FAL housing structure is reconfigured using topology optimization to construct chimney effect enhanced flow channels integrated with heat pipe bundle arrays, thereby establishing efficient heat conduction pathways from the phenolic resin substrate (PRS) to the structural periphery. Micro-element texture (MET) arrays are fabricated at the PRS thermal interface to enhance interfacial thermal conductance. Based on multi-physics coupled numerical simulation, a parametric mapping model correlating geometric topology with thermal performance is established through response interface methodology, enabling the parametric optimization of micro-texture configurations. A thermal interface performance-testing platform is constructed to validate the accuracy and reliability of the numerical model. Experimental results demonstrate that the integrated heat pipe technology effectively suppresses LED junction temperature rise; moreover, groove-type MET arrays oriented perpendicular to the gravity direction not only significantly increase the effective heat dissipation area but also optimize the dynamic characteristics of natural convection. This proposed solution reduces the maximum operating temperature of deep-sea FALs by 6.73 % compared with conventional structures, providing an effective engineering solution for thermal structural design of high-power illumination systems.
A planar prismatic Rubik's cube mechanism (PPRCM) is defined as a Rubik's-cube-inspired mechanism whose rigid components are constrained to pure planar movements. Taking a typical PPRCM prototype as the research carrier, this paper elaborates on the composition, topological configuration, and reconfigurable motion process of the mechanism. The influencing factors of PPRCM's topological structure are abstracted, and the conditions for realizing reconfigurable motion are thereby derived. Based on the reconfigurable topological characteristics of PPRCM, a type synthesis method for the mechanism is proposed. By specifying the values of the topological influencing factors, PPRCMs with different topological structures are generated, and corresponding three-dimensional(3D) models are constructed to validate the rationality and effectiveness of the proposed method. The type synthesis method for PPRCM proposed in this paper not only enables the development of more novel PPRCM configurations but also enriches and improves the type synthesis theories for planar mechanisms.
This paper proposes a composite control strategy combining a radial basis function (RBF) neural network and super-twisting sliding-mode control for high-precision trajectory tracking of the UR10 manipulator under parameter variations, nonlinear friction, and external disturbances. An RBF network is employed to approximate the lumped unknown nonlinear dynamics online, thereby reducing the equivalent disturbance upper bounds. Simultaneously, a super-twisting robust control term is introduced to compensate for approximation residuals and remaining disturbances, which ensures system robustness while effectively suppressing conventional sliding-mode chattering. Furthermore, a projection-based adaptive law is designed to guarantee the strict boundedness of the network weights. Based on Lyapunov theory, the finite-time convergence of the sliding variable and tracking error is proven. Simulations on a 6-degree-of-freedom UR10 manipulator – incorporating mass/inertia perturbations and Coulomb-viscous friction – demonstrate that the proposed method achieves high-precision tracking with small steady-state errors and smooth, chattering-free control torques, verifying its effectiveness and engineering applicability.
