四足机器人液压动力源非稳态工况下瞬态特性及控制策略研究

With the obvious advantages of good adaptability on complicated ground, quadruped robot has been the hot research topic in recent years. In order to resolving the problems that traditional matching method of engine-variable displacement pump cannot meet the requirement of controlling robot hydraulic source, this research will apply with one-dimensional coupled three-dimensional modeling and build up the transient simulation model, based on which the transient characteristics will be analyzed under non-steady working condition for the quadruped robot hydraulic power source. According to the transient response characteristic of hydraulic pressure source and the quadruped robot's loading regulations under different environment and gaits, the design scheme of hydraulic source will be optimized, and so will the matching rules of engine-variable displacement pump, engine speed control method under different loading work condition, and hydraulic source control strategy based on mode switching mechanism. On basis of transient characteristics of hydraulic source under different working conditions, its transient response capacity will be improved by revising the matching rules of engine-variable displacement pump and controlling the transient transition process under different operating points of stable state, consequently educing effective control strategy with low cost and sufficient power supply, so as to finally ensure robot's good adaptability under complex condition while prolonging its endurance. The research will better the theoretical foundation of hydraulic source design and propose some new method for similar system design and dynamic performance analysis.

四足机器人具有路面适应性强的优点，是近年来研究的热点之一。针对传统的发动机-变量泵匹配方法无法满足机器人液压源控制要求的问题，本研究拟采用一维三维耦合建模的方法建立四足机器人液压动力源瞬态仿真模型，基于该模型进行液压动力源在非稳态工况下的瞬态特性分析。基于液压源瞬态响应特性和四足机器人不同环境模式和步态下负载规律，开展液压源设计方案优化、发动机-变量泵匹配规律、变负载工况下发动机转速动态控制方法，以及基于模态切换机制的液压源控制策略的研究。研究基于液压动力源在非稳态工况下的瞬态特性，通过对发动机-变量泵稳态匹配规律进行修正和对不同稳态工作点之间瞬态过渡过程进行控制，提升液压动力源瞬态响应能力，制定经济性、动力性兼顾的控制策略，以实现：在延长机器人续航里程的同时保证机器人对复杂环境的适应能力。课题的开展有利于完善液压源设计的理论基础，为类似系统设计和动态性能分析提供了方法。

四足机器人是工作在不同环境模式，有着不同步态的系统。本研究主旨在于通过分析四足机器人不同环境模式和步态下的负载规律，基于液压动力源在非稳态工况下的瞬态特性，研究机器人液压动力源匹配规律和动态控制策略以实现四足机器人动力性能、经济性能兼顾的目标。（1）研究中对四足机器人静步态、动步态和动静转换步态进行了负载分析，得到了机器人不同步态的液压源负载规律。负载规律表明：在不同工况下，机器人液压源的压力负载和流量负载均有较大的波动。（2）基于机器人负载规律提出了发动机变负载工况下的控制方法，并进行了仿真分析和台架试验，试验结果表明控制方法可有效解决发动机变负载工况下的转速波动问题。（3）研究中以发动机目标转速作为变量进行了发动机和变量泵的匹配，同通过试验验证较好的满足了液压源控制的要求。研究提出的发动机和变量泵的匹配策略为进一步提高四足机器人液压源的效率和稳定性提供了有效方法。（4）完成了四足机器人电液混合动力源的原理设计，为进一步提高动力源的效率提供了解决方案。