## 1 Introduction  
Electrohydraulic lifting mechanisms have been increasingly used in launcher systems [1, 2, 3, 4, 5] in terms of their merits containing large force/torque output, high response and small size-to-power ratio. Nevertheless, due to strong nonlinearities (i.e., flow nonlinearity, friction nonlinearity and mechanism nonlinearity) and unmodeled uncertainties (i.e., unmodeled friction, parametric uncertainties and extern disturbances) in electrohydraulic lifting mechanisms of launcher systems, the achievement of high-accuracy tracking control for electrohydraulic lifting mechanisms of launcher systems is challenging [6, 7, 8, 9, 10]. Thus, to address this issue and achieve the improvement of control performance for electrohydraulic lifting mechanisms of launcher systems, it is necessary to investigate some efficient control methods. In the last few years, a lot of advanced controllers have been adopted to attain high-performance tracking for electrohydraulic actuator systems. Feedback linearization control found in [11, 12] was used to dispose of dynamic nonlinearities by utilizing the feedforward compensation method. To handle parametric uncertainties in electrohydraulic actuator systems, adaptive control was employed in [13], while it could not suppress unmodeled disturbances [14]. Adaptive robust control investigated in [14] could deal with parametric uncertainties and extern disturbances simultaneously and has been broadly adopted in practice [15, 16, 17, 18, 19]. Nonetheless, the theoretical analysis of this controller shows that bounded tracking performance was achieved in the presence of time-variant disturbances. By integrating a robust integral of the sign of the error feedback (RISE) [20] and backstepping method, a RISE-based backstepping controller was developed for hydraulic systems in [21, 22] to get an asymptotic stability while existing smooth disturbances. In addition,sliding mode control was used in [23] to suppress disturbances and improve control performance for hydraulic systems. A super-twisting controller (STC) is proposed in [24] to attain a finite-time stability. However, to suppress heavy disturbances, the achievable tracking performance in [21; 22; 23; 24] was pledged in a high-frequency/high-gain feedback way. That is, by this way, high-frequency dynamics might be stimulated and then the system might get unstable. To remove the effect of strong disturbances on control accuracy and improve the tracking performance, many disturbance estimators/observers have been developed. An extended state observer (ESO) in [25] was employed to estimate mismatched and matched disturbances and compensate them in a feedforward way. However, the asymptotic control performance of the system would be destroyed while facing time-variant disturbances. An unknown system dynamic estimator [26] was employed to dispose of unknown dynamics and modeling uncertainties for servo mechanisms, which only pledged a bounded stability when existing changing dynamics. Recently, an efficient sliding mode observer developed in [27] was used to dispose of pressure dynamics and force dynamics in hydraulic systems. In this way, an asymptotic stability was expected. However, the existence of the standard sign function could lead to serve chattering and even make the system unstable. Moreover, a distributed control framework presented in [28; 29] were adopted to dispose of various uncertainties for robot arms, which achieved the improvement of the control performance. In addition, compared to the above-mentioned control approaches for hydraulic actuators, the rapid-erection controller design of the electrohydraulic lifting mechanism in launcher systems considered in this paper is more complex due to its inherent mechanism nonlinearities. Consequently, how to design an asymptotic rapid-erection robust control method for the electrohydraulic lifting mechanism of the launcher system still is an open issue and deserve to study.