Chengwen Chai

This study addresses key challenges in high-precision industrial motion control, including dynamic load disturbances, nonlinear parameter coupling, and degradation in synchronization accuracy. A dual-motor cross-coupled synchronous control strategy is proposed, integrating Hertzian contact theory with an adaptive fuzzy PI control algorithm. First, a precise pressure measurement model for the printing contact zone is established based on Hertzian contact theory. The model quantitatively characterizes the relationship between structural parameters and pressure distribution. Key parameters include cylinder radius and plate thickness. This provides a theoretical foundation for precise regulation. Subsequently, a fuzzy PI controller with parameter self-tuning capability is incorporated into the motor speed loop, enabling real-time adjustment of control parameters to effectively compensate for system nonlinearities and time-varying disturbances. Furthermore, a cross-coupled synchronization architecture is designed to enable bidirectional compensation between the two motors, significantly improving synchronization accuracy under complex operating conditions. Simulations were performed in MATLAB/Simulink. The tests covered typical operational scenarios, including load start-up, single-motor disturbance, and multi-disturbance conditions. The results demonstrate that the proposed system achieves high performance: dual-motor speed synchronization accuracy reaches 99.5%; the response time for disturbance compensation is within 0.3 s; and printing-pressure fluctuation is confined to ±0.8%. This performance represents a 62.5% improvement in stability over conventional single-motor control systems. This research not only resolves the long-standing issue of pressure non-uniformity in flexographic printing but also provides a generalizable framework for multi-motor synchronous control in precision manufacturing. The findings offer substantial academic insight and practical value for advancing intelligent industrial measurement and control technologies.

Thanks to the advantages of the chain drive in abrasion resistance and service life, the application of timing chain trains in engine valve mechanisms has been on the rise in recent years. However, due to the particular characteristics of the chain drive, the polygon effect inevitably exists, causing vibration noise and motion unevenness of the chain drive system, which limits the development of the timing chain trains. In this paper, a V6 engine timing chain train is taken as an example. The effect of the polygon effect on the velocity, acceleration, and transmission ratio of the timing chain trains is verified by modeling and simulation with the virtual prototype analysis software Adams.

Flying splicer is a key component of web-fed offset presses for automatically replacing the exhausting web roll with a new one without stopping the machine. The composition and working principle of pneumatic controlling mechanism for operating the flying splicer is analyzed according to the processing requirements of automatic web alternation. By using the software FluidSim, the pneumatic sequential operation controlling circuitry with multi-cylinders for driving the flying splicer is designed, in which the air cylinders cooperate to accelerate the new reel to the circumferential velocity of the expiring web, paste the adhesive end of the new reel on the expiring web, and cut off the remaining piece of expired web. A system scheme and designing method of the PLC-based pneumatic controlling system suitable for automatic web roll change on high speed offset printing presses is brought out.