High-Robust Force Control for Environmental Stiffness Variation Based on Duality of Two-Inertia System

2021 ◽  
Vol 68 (1) ◽  
pp. 850-860
Author(s):  
Yusuke Kawai ◽  
Yuki Yokokura ◽  
Kiyoshi Ohishi ◽  
Toshimasa Miyazaki
2019 ◽  
Vol 11 (5) ◽  
Author(s):  
Jue Yu ◽  
Yong Zhao ◽  
Genliang Chen ◽  
Yeqing Gu ◽  
Chao Wang ◽  
...  

This paper puts forward a linear variable stiffness joint (VSJ) based on the electromagnetic principle. The VSJ is constituted by an annular permanent magnet (PM) and coaxial cylindrical coil. The output force and stiffness are linearly proportional to the coil current. In consequence, the stiffness adjustment motor and mechanisms required by many common designs of VSJs are eliminated. A physical prototype of the electromagnetic VSJ is manufactured and tested. The results indicate that the prototype can achieve linear force-deflection characteristics and rapid stiffness variation response. Using an Arduino and H-bridge driver board, the electromagnetic compliance control system is developed in order to realize the precise control of the interaction force. The static force control error is no more than ±0.5 N, and the settling time can be controlled within only 40 ms. At last, an experiment of squeezing the raw egg is conducted. The experiment intuitively exhibits the performance of electromagnetic compliance in stable force control and keeping safe robot-environment interaction.


2008 ◽  
Vol 35 (S 01) ◽  
Author(s):  
Y Li ◽  
J Randerath ◽  
G Goldenberg ◽  
J Hermsdörfer

2005 ◽  
Vol 32 (S 4) ◽  
Author(s):  
F Kirsten ◽  
S Bohlen ◽  
J Sommer ◽  
T Merl ◽  
P Saemann ◽  
...  

Author(s):  
K. Shibazaki ◽  
H. Nozaki

In this study, in order to improve steering stability during turning, we devised an inner and outer wheel driving force control system that is based on the steering angle and steering angular velocity, and verified its effectiveness via running tests. In the driving force control system based on steering angle, the inner wheel driving force is weakened in proportion to the steering angle during a turn, and the difference in driving force is applied to the inner and outer wheels by strengthening the outer wheel driving force. In the driving force control (based on steering angular velocity), the value obtained by multiplying the driving force constant and the steering angular velocity,  that differentiates the driver steering input during turning output as the driving force of the inner and outer wheels. By controlling the driving force of the inner and outer wheels, it reduces the maximum steering angle by 40 deg and it became possible to improve the cornering marginal performance and improve the steering stability at the J-turn. In the pylon slalom it reduces the maximum steering angle by 45 deg and it became possible to improve the responsiveness of the vehicle. Control by steering angle is effective during steady turning, while control by steering angular velocity is effective during sharp turning. The inner and outer wheel driving force control are expected to further improve steering stability.


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