单活塞式液压自由活塞发动机控制系统的开发

针对HFPE控制的各种要求,设计了单活塞式液压自由活塞发动机控制系统,提出了针对液压自由活塞发动机的控制策略.重点分析了活塞下止点位置修正和起动时活塞位置调整控制难点和面临的问题,根据液压自由活塞发动机特性提出了下止点位置修正控制策略.原理样机试验结果表明,该控制系统对液压自由活塞发动机的起动和连续运行的频率控制合理可靠,验证了控制策略的合理性和可行性;改善了液压自由活塞发动机下止点位置控制,保证了非正常情况下活塞回位,实现了可变压缩比控制,改善了冷起动和缸内燃烧效果.

Development of Control System for Single Piston Hydraulic Free Piston Diesel Engine

To meet various control requirements, a control system was designed and the control strategy was proposed for single piston HFPE engine. Aiming at the difficulties of adjustment and control piston position when starting up, the position of piston's bottom dead center (BDC) was corrected and controlled according to the characteristics of hydraulic free piston engine. Test of developed control system gives the following results. The control system could realize frequency control of HFPE starting and continuous operation with reasonableness and reliability. The presented control strategy is rational and feasible. The correction of controlling piston's BDC position is improved so that the ability of piston return could be guaranteed under abnormal circumstances. The control of variable compression ratio could be achieved and the performance of cold starting and cylinder combusting is enhanced.