Evaluation Method for Multidegree-of-Freedom Spherical Actuators Under Power Control

Takahara, Kenji; Hirata, Katsuhiro; Niguchi, Noboru; Nishiura, Yusuke; Sakaidani, Yo

doi:10.1109/tmag.2017.2697909

Cited by 7 publications

(6 citation statements)

References 13 publications

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“…This strategy only satisfies the torque demand, and the number of energized coils and the total current load are not considered. Accordingly, the evaluation function is constructed as (13). Txg, Tyg, and Tzg are the goal values of torques, used as the optimization goals by PSO.…”

Section: A Torque Dominant Strategymentioning

confidence: 99%

“…very time consuming, plus the black-box model accuracy is greatly depends on the distribution of the sample points. No matter using weighted undirected graphs [10], direct magnetic field feedback [11], torque map [12], torque domain estimation [13], or stator spherical domain partitioning [14], the determination process of drive current is usually even more complicated than torque calculation.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Drive Current Calculation and Analysis of Permanent Magnet Spherical Motor Based on Torque Analytical Model and Particle Swarm Optimization

Zhou

Wang

et al. 2020

IEEE Access

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In order to determine the currents required in different attitudes and torque target conditions, this paper proposes a calculation method for drive currents of permanent magnet spherical motors based on three-dimensional magnetic field, torque analytical model and optimization algorithm. Firstly, an electromagnetic torque analytical model base on equivalent surface currents of a permanent magnet and Lorentz force is proposed. The feasibility and accuracy are verified by comparing results with those by the finite element method. Then, an inverse calculation model of the motor drive current is built by combining the torque analytical model with the Particle Swarm Optimization (PSO) algorithm. At last, using the proposed drive current calculation model, the driving current characteristics of spherical motors under different energization strategies are compared and analyzed. INDEX TERMS Permanent magnet spherical motor, analytical model, electromagnetic torque, drive current, particle swarm optimization.

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Section: A Torque Dominant Strategymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Drive Current Calculation and Analysis of Permanent Magnet Spherical Motor Based on Torque Analytical Model and Particle Swarm Optimization

Zhou

Wang

et al. 2020

IEEE Access

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“…The 2-DOF torque area under copper loss limiting is shown in Fig. 3 [11]. The torque area is shown by an ellipse where the long and short axes indicate the maximum and minimum torque vectors, respectively.…”

Section: Torque Area Under Copper Loss Limitingmentioning

confidence: 99%

“…In the case of 3-DOF, the torque area is a polyhedron which has n C 2 faces, and simultaneous equations of planes must be considered. A torque area due to j-and kphase currents L j is shown in (11).…”

Section: Torque Area Under Current Limitingmentioning

confidence: 99%

“…However, these evaluations are locally conducted and the torque characteristics at all positions and around all axes are not evaluated. In order to completely evaluate the spherical actuators, we proposed a torque area method [11]. The proposed method can evaluate the static torque characteristics using a torque area that is composed of torques around arbitrary axes under copper loss limiting.…”

Section: Introductionmentioning

confidence: 99%

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Torque Evaluation Method for Multi-Degree-of-Freedom Spherical Actuators Considering Cogging Torque under Current Limiting

Takahara

Hirata

Niguchi

2019

Journal of the Japan Society of Applied Electromagnetics and Me

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Multi-Degree-of-Freedom (Multi-DOF) actuating systems are composed of several single-DOF motors, which results in large, heavy and complicated structures. In order to solve these problems, various multi-DOF spherical actuators have been actively studied. Among them, a spherical actuator can generate torques in arbitrary positions and directions. However due to this, it is difficult to evaluate the torque characteristics at any position all over the movable range. In order to evaluate the spherical actuators, we proposed a torque evaluation method under copper loss limiting. However, in the proposed method, only copper losses can be considered. In this paper, we propose a new torque evaluation method considering a maximum current limiting. Finally, the torque characteristics of our multi-DOF actuators are evaluated using the proposed method and the effectiveness of the proposed method is verified.

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Friction torque field distribution of a permanent‐magnet spherical motor based on multi‐physical field coupling analysis

Wang

et al. 2021

IET Electric Power Appl

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Non‐linear friction between the rotor and the rotor support mandrels would occur during the movement of the permanent‐magnet spherical motor (PMSpM). The friction which varies with the position causes PMSpM jitter or even stop it when running at low speeds, and the system operation accuracy is reduced. To solve these problems, this work proposes a parameter identification method of the Coulomb friction model. First, a dynamics model with the Coulomb friction of PMSpM is established by using generalised Euler angles and the Lagrangian energy method. Then, a parameter identification method of the Coulomb friction model based on COMSOL Multi physics coupled simulation and MEMS experiment is proposed to obtain the friction torque data of the PMSpM. Finally, the friction torque compensation in a closed‐loop control experiment is completed by using the friction data. The results show that the accuracy of trajectory tracking control is significant, and the error is reduced by 49.32%. Hence, the distribution of the friction torque field is accurate and effective.

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Evaluation Method for Multidegree-of-Freedom Spherical Actuators Under Power Control

Cited by 7 publications

References 13 publications

Drive Current Calculation and Analysis of Permanent Magnet Spherical Motor Based on Torque Analytical Model and Particle Swarm Optimization

Drive Current Calculation and Analysis of Permanent Magnet Spherical Motor Based on Torque Analytical Model and Particle Swarm Optimization

Torque Evaluation Method for Multi-Degree-of-Freedom Spherical Actuators Considering Cogging Torque under Current Limiting

Friction torque field distribution of a permanent‐magnet spherical motor based on multi‐physical field coupling analysis

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