Structural optimization of a new type of lever-assisted gear reducer based on a genetic algorithm

Wang, Zeyu; Song, Yuan; Shan, Xianjie; Gan, Dongming

doi:10.5194/ms-12-333-2021

Cited by 3 publications

(4 citation statements)

References 8 publications

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“…The motor torque output is usually obtained by sensor, which demands more space and increases complexity of control system. As for SPM motor, under i d = 0 control strategy, the torque output is considered to be obtained by calculation, as shown in Equation (13).…”

Section: Control Algorithmmentioning

confidence: 99%

“…Several motors have been designed for robot joints [11,12]. For the exoskeleton, the joint ending speed is usually low, while the torque requirement is high; thus the outer rotor SPM (OR-SPM) motor is employed, and the reducer can be located inside the stator [13,14]. On the other hand, a small size of the joint is critical to the action flexibility of the exoskeleton.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Design of a High Torque Density Robot Joint and Analysis of Force Control Method Applied for a Light Exoskeleton

et al. 2023

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In many robotic applications, the joint is required to have a small volume, low weight and high torque output. In this paper, based on the finite element analysis (FEA), a 36-slot 40-pole outer rotor surface-mounted permanent magnet (OR-SPM) motor with concentrated winding is designed for the exoskeleton robot. The fractional slot concentrated winding (FSCW) is employed to reduce end winding height, leading better portability. Since the motor is relatively flat, the 3D end effect is critical to the electromagnetic performances. Special attention is paid to 3D end effect during the multi-objective optimization of the OR–SPM motor. In order to increase the ending torque output, the planetary reducer is located between OR–SPM motor and load, and then system level optimization covering motor and reducer is carried out to achieve best torque output. In addition, the force impendence control method with parameter self-adaptive capability is proposed to improve user experience of the exoskeleton robot, where the key parameters in the algorithm vary according to different actions of the exoskeleton. In addition, the inertia of load is calculated using the parameter identification based on least squares method. Finally, the prototype of the joint is fabricated and tested to validate the above FEA results and control method. The user experience of the exoskeleton robot is also covered.

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Section: Control Algorithmmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Design of a High Torque Density Robot Joint and Analysis of Force Control Method Applied for a Light Exoskeleton

et al. 2023

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“…This paper has proposed a compound strategy with minimum flow and speed compensation and servo control. For details, see Li et al (2018) and Hu et al (2019). The robotic planning path trajectory generator provides a reference joint angle through the servo controller with the PD strategy.…”

Section: Optimal Design Of Controllermentioning

confidence: 99%

Kinematics analysis of a four-legged heavy-duty robot with a force–position hybrid control servo actuator in a parallel-executed cylinder system

Wang

et al. 2021

Mech. Sci.

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Abstract. In this research, an electrohydraulic servo four-legged heavy-duty (FLHD) robot has been designed and developed. The study proposes an integration layout cylinder design scheme for a non-lightweight hydraulic servo four-legged robot with high loads and torques of hip joint and derives the mathematical element analysis model for a parallel-executed cylinder (PEC) system. The multiple inherent characteristics of the PEC integration system model are explored further. Based on the controllable functional requirements of interconnected joints, and to weaken the influence of internal force coupling, a force–position hybrid control scheme for the PEC is designed, and the force–position signal module design unit is used to solve the force–position hybrid control in reverse. Considering the inherent requirements of the servo-executed cylinder (SEC) force control unit module (CUM), the implementation process of magnetic flux compensation and speed compensation is discussed in detail. The minimum amplitude controller is applied to the SEC force CUM, and the proportional integrated controller has been determined in the SEC position CUM. A compound control strategy proposed in this paper is verified on a parallel hydraulic servo platform. The experimental verification results reveal that the values of position/force attenuation amplitude and lag phase are not greater than 9 % and 18∘, respectively. The feasibility of the interconnected implementation of the hybrid control scheme proposed in this paper is further increased. The conclusions of this research will be useful for application in fields of four-legged heavy-load (FLHL) robot control systems.

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“…Precision transmission mechanisms are the core part in intelligent equipment, such as industrial robot and NC machine tools, and its performance is one of the key factors to determine the performance of equipment [1][2][3]. Traditional mechanical accuracy improvement is the main way to enhance the performance of transmission mechanisms [4,5].…”

Section: Introductionmentioning

confidence: 99%

A Denoising Algorithm Combined with EMD and LMS for Precise Transmission Signal

Song,

Cao,

Zhou

et al. 2023

Shock and Vibration

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High accuracy and stability in mechanical transmission are crucial for various applications. In spite of the validity of mechanical enhancements, control algorithms’ fulfilment offers a cost-effective and efficient approach to mitigating the effects of noise signals. This study presents a hybrid algorithm that combines EMD with the least mean square (LMS) error to achieve online denoising. Within the algorithm, consecutive mean square error (CMSE) and the l2-norm metric are employed to assess the similarity between intrinsic mode functions (IMFs) and the original signal; therefore, IMFs are separated into three distinct components: noise components, information components, and mixed components. The denoised signal is obtained by partial reconstruction. Subsequently, the denoised signal is employed as a reference signal in the LMS algorithm, which is utilized for practical processing. The performance evaluation of the developed algorithm employs simulation and experimental signals. The obtained results illustrate that the presented approach achieves sufficient accuracy and stability.

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Structural optimization of a new type of lever-assisted gear reducer based on a genetic algorithm

Cited by 3 publications

References 8 publications

Design of a High Torque Density Robot Joint and Analysis of Force Control Method Applied for a Light Exoskeleton

Design of a High Torque Density Robot Joint and Analysis of Force Control Method Applied for a Light Exoskeleton

Kinematics analysis of a four-legged heavy-duty robot with a force–position hybrid control servo actuator in a parallel-executed cylinder system

A Denoising Algorithm Combined with EMD and LMS for Precise Transmission Signal

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