## 1 Introduction  
As global environmental pollution and energy shortages continue to intensify, green, energy saving, and environmental protection have attracted widespread attention from all over the world [1, 2]. Construction machinery (CM) has low energy efficiency and poor emissions, which has gradually been unable to meet the need of the times. Electric CM using a motor instead of an engine can achieve zero emission, and is treated as a major trend in industrial development [3, 4]. At present, the electric motor control system is relatively mature [5, 6], many advanced control methods are employed [7]. However, due to the complicated working conditions and the violent load fluctuations, the existing motor controller used in the industrial field and other stable load conditions cannot adapt well to the operating characteristics of the CM [8, 9]. Research on electric motor control systems based on the CM load characteristics has gradually attracted attention. Control strategies for the electric motor are mainly vector control and direct torque control (DTC). DTC has the advantage of fast dynamic response, but it also has the disadvantage of large torque ripple, poor low-speed performance, and low current utilization [10, 11]. Vector control adopts coordinate transformation to equate the mathematical model of the alternating current (AC) motor to the direct current (DC) motor [12, 13]. While simplifying the control method, it obtains the control performance comparable to that of the DC motor. Compared with the DTC, the speed regulation range of vector control is wider, the low-speed performance is better, and the current utilization is higher. The working condition of electric CM is complex. Therefore, special research on its power motor is needed [14]. [PERSON] et al. designed a novel DTC for a permanent magnet synchronous motor (PMSM) in hybrid power train system to reduce the influence of DC voltage on the maximum output torque of the PMSM. The results demonstrated that the proposed DTC can reduce the effect of DC voltage variation on the maximum output torque of the PMSM [15]. [PERSON] et al. employed a segmented Halbach permanent magnet (PM) array for the permanent magnet synchronous generator rotor configuration for the PMSM structure. The results showed that this method effectively improved the energy-saving efficiency of the hydraulic system [16]. [PERSON] et al. proposed a novel type of sliding mode controller that combines intelligent control and phase-locked loop. Through simulation and experiments, it was verified that the motor control system had the characteristics of smooth switching, good tracking response, and strong anti-interference ability [17]. [PERSON] et al. proposed a control strategy for a hybrid-excitation salient-pole PMSM in which the armature winding and the DC excitation winding were located on the stator at the same time. The simulation verified that the control strategy met the motor requirements of electric vehicles and hybrid electric vehicles, and the control strategy had superior responsiveness and robustness [18]. Currently, the development of AC motor control strategies mostly makes simple improvements on traditional control strategies, without analyzing the working conditions of CM [19]. The traditional vector control adopts the PI controller for closed-loop regulator design of speed and current [20]. Electric CM has severe load fluctuations and complex working conditions, which is a typical load time-varying system. The fixed PI parameters of traditional control cannot change with the load variation, which results in poor dynamic adjustment ability and poor anti-load disturbance ability of the controller. Considering the complex working conditions of CM, the PI parameters of the motor controller should be adjusted in real time according to the characteristics of CM working conditions. PI parameter online tuning technology mainly includes online tuning based on model parameters and intelligent algorithms [21].