To enhance the dynamic performance and disturbance rejection capability of the permanent magnet synchronous motor speed control system, a novel speed control method based on a novel sliding mode control (NSMC) and load torque observer is proposed on the basis of model predictive current control (MPCC) with a sliding mode disturbance observer. First, on the basis of MPCC, the influence of parameters such as resistance, inductance, and flux linkage on MPCC is analyzed. To address the aggregated disturbance caused by parameter mismatches, a piecewise square-root switching function sliding mode disturbance observer (SMDO) is designed to enhance the robustness of the parameters. To address the poor dynamic performance and inadequate robustness resulting from the proportional-integral-controller (PI) velocity loop control in the MPCC, a novel NSMC velocity control method is proposed. This method utilizes the hyperbolic sine function and fractional-order integral sliding mode surface, resolving the dilemma faced by traditional slide mode controllers (SMC) in balancing fast response and reduced vibration. Additionally, to enhance the system’s disturbance rejection capability, a sliding mode torque observer (SMTO) is designed to continuously update the observed load torque value into the NSMC controller, achieving speed compensation control. Finally, through comparative experiments among the proportional integral controller (PI), SMC, NSMC, and NSMC + SMTO, the results indicate that the proposed NSMC + SMTO exhibits the best speed response, steady-state characteristics, and disturbance rejection capability.

To realize advanced velocity regulation for permanent magnet synchronous motors (PMSM) in servo control and enhance the capability to resist disturbances of load and inertia, a disturbance-resistant adaptive fast super-twisting algorithm (FSTA) speed control method is proposed. To address the challenge of of chattering caused by the conventional exponential reaching law in sliding mode control (SMC), a FSTA reaching law is proposed. Introducing an integral sliding surface simultaneously to avoid the requirement of PMSM acceleration in the control input, decreasing the static error of the system. Furthermore, replacing the sign function sgn(s) in the FSTA reaching law with the continuous function sigmoid(s) to further enhance the system’s responsiveness and stability in varying conditions. To address the issue of system instability caused by inertia and load variations, an extended sliding mode observer (ESMO) and model reference adaptive system (MRAS) method are for the purpose of achieving real-time observation of load torque and rotational inertia, respectively. The observed torque values and identified inertia values are then updated in the FSTA control, enabling adaptive FSTA speed control. The outcomes of the experiment show that, compared to the traditional adaptive SMC and STA speed control method, the proposed adaptive FSTA control method in this paper exhibits superior dynamic performance and stronger disturbance rejection capability against load and inertia.

Accurate rotor position detection is essential for high-speed machine control systems, yet stable rotor position sensors for operations exceeding 30 krpm are lacking. While resolvers are renowned for their structure robustness in high-speed applications, the necessity for high-frequency enveloping during decoding leads to significant measurement errors as speeds increase, thereby restricting their applications in high-speed scenarios. This letter introduces a novel hybrid-excited resolver scheme designed to generate easily decodable signals for high-speed applications. The scheme employs conventional high-frequency voltage excitation at low speeds, and shifts to adjustable direct current excitation beyond a critical speed threshold, during which the resolver produces orthogonal output signals in the form of back-EMF with a consistent amplitude. By eliminating the need for high-frequency signal enveloping, this method enables the resolver to operate at ultra-high speeds without requiring complex structural modifications. Both simulations and experiments corroborate the effectiveness of this approach, validating its potential for practical applications.

Permanent magnet synchronous motor (PMSM) servo system is the control and execution mechanism of spacecraft, and its precise modeling is of great practical significance for improving the performance of the spacecraft. A comprehensive model considering elasticity, backlash, and friction was established based on the structural composition and transmission characteristics of spacecraft. Firstly, an elastic-dead zone model was established based on the transmission characteristics, with two mass elastic and gear backlash dead zones as the main features. Then, an improved LuGre friction model was established that considers the effects of vibration and environmental temperature, and the three models were organically combined. Finally, a method for identifying nonlinear parameters of the system using sinusoidal sweep and the least squares method was proposed, and the accuracy of the constructed model was verified. The experiment shows that the error of the simulation results is consistent with the experimental results. This method can precisely obtain the servo system model, providing theoretical support for control method research.

To enhance the anti-inertia disturbance ability of permanent magnet synchronous motor (PMSM) speed system, an adaptive sliding mode control with inertia identification is proposed. A novel sliding mode control (NSMC) based on a new reaching law coupled with model reference adaptive system (MRAS) inertia identification is realized the adaptive control, named MRAS+NSMC. In the NSMC construct process, an integral sliding mode surface and a variable speed reaching law are introduced to avoid speed differentiation and improve dynamics, respectively. And the new reaching law imported a successive sigmoid( s) to replace the traditional sign( s) to suppress chattering phenomena. For the problem that the performance deteriorated by rotational inertia variation caused by load changes, the inertia is estimated in real time according to the MRAS theory, and the identification value is updated to the NSMC controller to realize adaptive MRAS+NSMC speed control. Experimental results show that the proposed adaptive MRAS+NSMC control has a faster speed response, and the speed response time is reduced from 85 to 49 ms compared with conventional SMC control. In addition, it has strong robustness to inertia disturbances and high speed tracking accuracy. Compared with conventional SMC, the speed tracking accuracy of proposed MRAS+NSMC is increased from 12% to 4%. This makes the proposed MRAS+NSMC control has great potential practical significance for speed control of PMSM.