To eliminate the static error, overshoot, and vibration of the series elastic actuator (SEA) position control, the resonance ratio control (RRC) algorithm is improved based on L1 adaptive control(L1AC)method. Based on the analysis of the factors affecting the control performance of SEA, the algorithm schema is proposed, the stability is proved, and the main control parameters are analyzed. The algorithm schema is further improved with gravity compensation, and the predicted error and reference error is reduced to guarantee transient performance. Finally, the effectiveness of the algorithm is validated by simulation and platform experiments. The simulation and experiment results show that the algorithm has good adaptability, can improve transient control performance, and can handle effectively the static error, overshoot, and vibration. In addition, when a link-side collision occurs, the algorithm automatically reduces the link speed and limits the motor current, thus protecting the humans and SEA itself, due to the low pass filter characterization of L1AC to disturbance.

翻译：为消除串联弹性执行器(SEA)位置控制中的静态误差、超调及振动问题，基于L1自适应控制(L1AC)方法改进了谐振比控制(RRC)算法。通过分析影响SEA控制性能的因素，提出算法架构并证明其稳定性，同时分析主要控制参数。进一步引入重力补偿改进算法架构，减小预测误差与参考误差以保证暂态性能。最后通过仿真和平台实验验证算法有效性。仿真与实验结果表明，该算法具有良好的适应性，能提升暂态控制性能，有效处理静态误差、超调及振动问题。此外，由于L1AC对扰动的低通滤波特性，当连杆侧发生碰撞时，算法可自动降低连杆速度并限制电机电流，从而保护人体与SEA本体。