Robust Sliding Mode Control of PMSM Based on Rapid Nonlinear Tracking Differentiator and Disturbance Observer

Abstract

Torque ripples caused by cogging torque, flux harmonics, and current measurement error seriously restrict the application of a permanent magnet synchronous motor (PMSM), which has been paid more and more attention for the use in inertial stabilized platforms. Sliding mode control (SMC), in parallel with the classical proportional integral (PI) controller, has a high advantage to suppress the torque ripples as its invariance to disturbances. However, since the high switching gain tends to cause chattering and it requires derivative of signals which is not readily obtainable without an acceleration signal sensor. Therefore, this paper proposes a robust SMC scheme based on a rapid nonlinear tracking differentiator (NTD) and a disturbance observer (DOB) to further improve the performance of the SMC. The NTD is employed to providing the derivative of the signal, and the DOB is utilized to estimate the system lumped disturbances, including parameter variations and external disturbances. On the one hand, DOB can compensate the robust SMC speed controller, it can reduce the chattering of SMC on the other hand. Experiments were carried out on an ARM and DSP-based platform. The obtained experimental results demonstrate that the robust SMC scheme has an improved performance with inertia stability and it exhibits a satisfactory anti-disturbance performance compared to the traditional methods.

Fast Terminal Sliding Mode Control of Permanent Magnet In-Wheel Motor Based on a Fuzzy Controller

“…where u a , u b , and u c are the voltages in the three-phase stationary-coordinate abc system, respectively, u dc is the DC bus voltage of the power unit and is the upper power switch state of one leg, when the upper power switch is on or off, as shown in Figure 1. The layout of the voltage space vectors of the VSI is shown in Figure 2 [36]. where a u , b u , and c u are the voltages in the three-phase stationary-coordinate abc system, respectively, dc u is the DC bus voltage of the power unit and is the upper power switch state of one leg, when the upper power switch is on or off, as shown in Figure 1.…”

“…where a u , b u , and c u are the voltages in the three-phase stationary-coordinate abc system, respectively, dc u is the DC bus voltage of the power unit and is the upper power switch state of one leg, when the upper power switch is on or off, as shown in Figure 1. The layout of the voltage space vectors of the VSI is shown in Figure 2 [36]. In order to simply the mathematical model, state variables from the abc static system can be converted to an αβ static system using the Clark transformation and the αβ static system can be converted to a dq rotating system using the Park transformation [37]:…”

Robust Dynamic Sliding Mode Control-Based PID–Super Twisting Algorithm and Disturbance Observer for Second-Order Nonlinear Systems: Application to UAVs

“…where Ω r represents the total residual angular speed of motors and g = 9.81 m/s 2 denotes the gravitational acceleration. The remaining parameters from Equations (32) and (33) are shown in Table 1. Moments of inertia along three axes x,y and z in the Earth frame m (kg)…”

A SAKF-Based Composed Control Method for Improving Low-Speed Performance and Stability Accuracy of Opto-Electric Servomechanism

“…ω n is the difference between d(k + 1) and d(k), which can be regarded as a white noise; meanwhile, n m (k) is the measurement noise of the speed obtained from encoder, and n(k) is the process noise of the state variable x(k). According to (5) and (6), a relationship between A d , B d and p, K can be derived as:…”

“…Additionally, if the cut-off frequency is set too low, the disturbance cannot be effectively observed, resulting in an unsatisfactory disturbance suppression effect. Since the cut-off frequency of the Q filter needs to be determined in reference to the actual characteristics of the OES, it is difficult for the DOB to obtain an optimal observation for the servomechanisms whose parameters change drastically, thus it is usually necessary to combine DOB with other advanced controllers, such as sliding mode controller(SMC) [5], to get a better motion performance.…”