In this article, a decentralized tracking control scheme is proposed for a class of nonlinear interconnected systems with uncertainties using sliding mode technique. Both matched nonlinear uncertainty and mismatched known nonlinear interconnections are considered. Under the condition that the nominal isolated subsystems have relative degrees, a geometric transformation is applied to transfer the interconnected system into a new nonlinear interconnected system with a special structure to facilitate the system analysis and design. Then, a composite sliding surface is designed in terms of tracking errors, and decentralized controllers are proposed to drive the system states to the designed sliding surface in finite time and maintain a sliding motion on it thereafter. A set of conditions are developed to guarantee that the output tracking errors converge to zero asymptotically while all system state variables are bounded. The considered interconnected systems are nonlinear and it is not required that either the isolated subsystems or the isolated nominal subsystems are linearizable. The desired output signals are allowed to be time‐varying. Finally, the developed results are applied to an inverted coupled‐pendulum system. Simulation demonstrates that the proposed control scheme is effective.

In this paper, an improved online torque compensation strategy considering phase torque-generation capability is proposed to enhance the conventional torque-sharing function (TSF), thus reducing torque ripple for switched reluctance machines (SRMs). The improvements are mainly attributed to two aspects: First, the phase turn-on angle and TSF starting angle are separated. Thus, the phase turn-on angle can be advanced independently to enhance the torque-generation capability of the incoming phase. Second, to generate the desired torque with minimum current, the torque per ampere (TPA) characteristic is considered for commutation region separation. This can ensure that in each separated region, the phase with a stronger torque-tracking ability is utilized for torque error compensation. Accordingly, efficiency is not sacrificed. In addition to improving the TSF, a direct instantaneous torque control (DITC) method combined with a PWM regulator is proposed to reduce large torque increments due to the limited control frequency. As a result, the torque ripple can be further suppressed. Finally, an experimental setup is established, and tests are conducted under different working conditions. The results demonstrate the effectiveness of the proposed method.

In this paper, a method for determining the optimal stator-rotor combinations of conventional flux-switching permanent magnet (FSPM) machines with composite phase numbers covering symmetrical and asymmetrical topologies is proposed by changing the equivalent number of coils per pole per phase (ENCPP) or the number of coil-pairs having complementarity (K) of the optimal stator-rotor combinations of the corresponding machines with prime phases. Taking composite phase machines such as four-phase, six-phase, nine-phase, and twelve-phase machines as examples, a detailed analysis is conducted on how the optimal stator-rotor combinations of four-phase machines are derived from the optimal stator-rotor combinations of the corresponding prime phase machines (i.e., two-phase machines) and how the optimal stator-rotor combinations of six-phase, nine-phase, and twelve-phase machines are derived from the optimal stator-rotor combinations of the corresponding prime phase machines (i.e., three-phase machines). Then, the winding factor of the conventional FSPM machines with composite phase numbers is calculated. Finally, taking a 24-slot/22-tooth (24/22) conventional FSPM topology as an example, the topology is connected into a standard six-phase machine (symmetrical topology) and a dual three-phase machine (asymmetrical topology), and a comparative study between them is conducted in terms of the phase back electromotive force (EMF) waveform, electromagnetic torque, torque ripple, and inductances. The results indicate that both machines have sufficiently large and symmetrical back-EMFs, as well as sufficiently large electromagnetic torque, which validates the correctness of the proposed method for determining the optimal stator-rotor combinations.

Distributed-drive electric vehicles (DDEVs) offer strong agility but face challenges in achieving fast dynamic response and robust stability under demanding conditions. To address this, we propose a hierarchical motion control framework that decouples path-following from attitude stabilization. A fixed-time extended state observer (FTESO) is designed to mitigate disturbance estimation errors from model inaccuracies, while a fractional-order sliding mode control (FOSMC) ensures accurate trajectory tracking. A multiobjective optimization model incorporating dynamic constraints and actuator limits is formulated and transformed into a constrained quadratic programming (QP) problem. Experiments on a 1:5 scaled chassis demonstrator validate the approach, showing a 42% reduction in lateral tracking error and sub-5-ms response time, outperforming state-of-the-art methods.