Coupling Modeling of Humanoid Flexible Joint and Vibration Suppression at Variable Load

doi:10.16183/j.cnki.jsjtu.2021.342

Abstract

Abstract:

Aimed at the joint vibration problem caused by the load change of humanoid flexible joint, a torque compensation control method based on state observer is proposed. By controlling the motor to output a torque increment equivalent to the disturbance torque, the joint torque can quickly balance the load torque and shorten the oscillation process of the elastic element passively adapting to the load change. A state observer for estimating load disturbance torque and motor speed is designed, whose convergence is proved by the Lyapunov function. The control structure of the drive system based on the proportional integral-intergral proportional (PI-IP) speed regulator is established, and the observer output feedforward link is added to the speed regulator to improve the anti-interference ability of the system. The simulation results show that compared with proportional integral differential (PID) control and joint force feedback proportional differential (PD) control, the proposed method can restore the motor speed to stability within 0.6 s after load change and realize joint vibration suppression within 1 s. Besides, the joint speed adjustment time is shortened by about 1.8 s and 0.9 s respectively, which effectively improves the dynamic adjustment ability of the system. Finally, the effectiveness of the proposed method was verified by experiments on an integrated flexible joint testing platform.

Key words: humanoid flexible joint, vibration suppression, torque compensation control, state observer

CLC Number:

TP273

SONG Chuanming, DU Qinjun, LI Cunhe, LUO Yonggang. Coupling Modeling of Humanoid Flexible Joint and Vibration Suppression at Variable Load[J]. Journal of Shanghai Jiao Tong University, 2023, 57(5): 601-612.

Figures/Tables 14

Fig.1

Tab.1

Definition of generalized coordinates

广义坐标与广义力标识	电磁部分				机械传动部分
	定子			转子	电机转角 j=4	手臂转角 j=5
	j=1	j=2	j=3	转子	电机转角 j=4	手臂转角 j=5
A_j	q_a	q_b	q_c	ψ_r	θ₁	θ
$A · j$	i_a	i_b	i_c	—	$θ · 1$	$θ ·$
$Q j A$	F₁	F₂	F₃	—	F₄	F₅

Tab.1

Fig.2

Fig.3

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Fig.5

Tab.2

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参数	设定值
驱动电机额定电压/V	12
驱动电机额定转速/(r·min^-1)	1200
电枢绕组等效电感/mH	1.4
电枢绕组等效电阻/Ω	24
转子转动惯量/(kg·m²)	0.062
手臂转动惯量/(kg·m²)	0.45
电机电磁阻尼系数/(N·m·s·rad^-1)	0.2
关节机械阻尼系数/(N·m·s·rad^-1)	0.5
关节刚度系数/(N·m·rad^-1)	10
减速器减速比	100∶1