Sensorless vector control of PMSM with non-sinusoidal flux using observer based on FEM

Traditional control methodologies of rehabilitation orthoses/exoskeletons aim at replicating normal kinematics and thus fall into the category of kinematic control. This control paradigm depends on pre-defined reference trajectories, which can be difficult to adjust between different locomotor tasks and human subjects. An alternative control category, kinetic control, enforces kinetic goals (e.g., torques or energy) instead of kinematic trajectories, which could provide a flexible learning environment for the user while freeing up therapists to make corrections. We propose that the theory of underactuated potential energy shaping, which falls into the category of kinetic control, could be used to generate virtual body-weight support for stroke gait rehabilitation. After deriving the nonlinear control law and simulating it on a human-like biped model, we implemented this controller on a powered ankle-foot orthosis that was designed specifically for testing torque control strategies. Experimental results with an able-bodied human subject demonstrate the feasibility of the control approach for both positive and negative virtual body-weight augmentation.

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“…

T_{e} = false(3 P / 2 false) \cdot λ_{m} \cdot i_{q},

where P is the number of motor poles, λ m is the motor flux linkage, and i q is the active current in the d–q rotating reference frame [22]. …”

Section: Hardware Design Of Pafomentioning

confidence: 99%

Experimental implementation of underactuated potential energy shaping on a powered ankle-foot orthosis

Zhu

Elery

et al. 2016

2016 IEEE International Conference on Robotics and Automation (ICRA)

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“…By adding the decoupling voltages, the final values of the reference voltages are obtained. To generate control signals, the space vector pulse width modulation is preferred due to constant switching frequency and better harmonic response [14,20]. Three methods using ADF algorithms are presented to reduce torque and speed ripple on determining injection of appropriate current harmonics.…”

Section: Foc Of Pmsmmentioning

confidence: 99%

Section: Adaptive Decision Fusion Based Torque Ripple Reductionmentioning

confidence: 99%

Online adaptive decision fusion based torque ripple reduction in permanent magnet synchronous motor

Erken

Öksüztepe²,

Kürüm³

2016

IET Electric Power Applications

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In this paper, new methods for reducing the torque ripple in permanent magnet synchronous motor are proposed. The methods are based on injection of appropriate current harmonics to motor by using adaptive decision fusion algorithms. Three different methods are used in determining injection of current harmonics based on q-axis current, q-axis voltage and reference value of the q-axis current. In these methods, the decision values are linearly c o m b i n e dw i t hw e i g h t s ,w h i c ha r eu p d a t e do n l i n ea c c o r d i n gt oa na c t i v ef u s i o nm e t h o d ,b a s e do np e r f o r m i n g orthogonal projections onto convex sets describing these values. The validity of the proposed methods is tested with experimental studies under different operating conditions.

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“…Studies show that 3-phase conduction mode has a better torque-speed capability than the first method in the constant power region [1]. Various advance speed controllers and advance converters [2][3][4][5], either with a sensor or sensorless [6][7][8][9], have been introduced by researchers to date. The first strategy is called the hysteresis method and works based on the relationship between machine torque and current.…”

Section: Introductionmentioning

confidence: 99%

Simplified model predictive current control of non-sinusoidal low power brushless DC machines

Eshkevari¹,

Torkaman²

2020

Turk J Elec Eng & Comp Sci

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Several strategies have been proposed to control nonsinusoidal brushless DC machines (BLDCMs). However, high electromagnetic torque ripple and current overshoots occur in commutation times, which are significant problems of those strategies such as for hysteresis current controllers. This paper proposes a model predictive strategy to solve the above issues. It is simple and straightforward. Moreover, it reduces the motor torque ripple significantly and improves the response rate of the control system to the load torque variation in comparison with the conventional technique. The torque varies smoothly, and the performance of the system at commutation time is improved by eliminating the adverse effects of commutation times on the machine's current and torque. This method also operates better than the conventional controller in medium switching frequencies. The novelty of this strategy is that it employs a model predictive strategy to realize the above claims. The real implementation possibility and performance of the controller are investigated by simulations for a 60-V/180-W/300-RPM BLDCM. This paper also compares the proposed current controller with the conventional controller. The results show that the torque ripple reduces 50%, and the brake and response times are improved.

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Sensorless vector control of PMSM with non-sinusoidal flux using observer based on FEM

Cited by 12 publications

References 17 publications

Experimental implementation of underactuated potential energy shaping on a powered ankle-foot orthosis

Experimental implementation of underactuated potential energy shaping on a powered ankle-foot orthosis

Online adaptive decision fusion based torque ripple reduction in permanent magnet synchronous motor

Simplified model predictive current control of non-sinusoidal low power brushless DC machines

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