Abstract: For the coexistence of matched and unmatached disturbances in electro-hydraulic servo systems, a new high-precision motion tracking strategy was proposed, where the needs of transient and steady-state performance were all taken into account. A valve-controlled electro-hydraulic position servo system was chosen as the example, the nonlinear mathematical model including matched and unmatched disturbances was established, prescribed performance function was defined to plan the control errors, and the planned conversion errors were used for backstepping design, while a new continuous asymptotic control technology was integrated to deal with the matched and unmatched disturbances based on the estimation of disturbance upper bound. Finally, the pre-designable transient performance and asymptotic steady-state performance were obtained, and the stability proof was derived via Lyapunov analysis. Tracking experiments under two position commands show that compared with PID and feedback linearization control, tracking accuracy in the initial stages is improved by over 22.9%. Compared with the controller only containing prescribed performance function, tracking accuracy in the steady-states is further improved by over 42.9%.

Key words: electro-hydraulic servo system, prescribed performance, asymptotic stability, matched and unmatched disturbance, motion control

摘要： 针对电液伺服系统匹配和不匹配干扰共存的特点，兼顾瞬态性能和稳态性能需求，提出一种新型高精度跟踪控制策略。以阀控电液位置伺服系统为例，建立了包含匹配和不匹配干扰的系统非线性数学模型，定义预设性能函数规划控制误差，基于规划后的转换误差设计反步控制器，并融合采用干扰上界估计的连续渐近控制技术处理匹配和不匹配干扰，获得了可预设的瞬态性能和渐近稳态性能，通过Lyapunov分析证明了稳定性。两种位置指令跟踪试验的结果表明，相比PID控制和反馈线性化控制，初始阶段跟踪精度提高超22.9%，相比仅引入预设性能函数的控制器，稳态跟踪精度提高超42.9%。

关键词: 电液伺服系统, 预设性能, 渐近稳定, 匹配和不匹配干扰, 运动控制