US 12,115,653 B2
Soft joint gripper based on 4D printing and consistency control method thereof
Yuyan Zhang, Qinhuangdao (CN); Shiying Kou, Qinhuangdao (CN); Xiaoyuan Luo, Qinhuangdao (CN); Yintang Wen, Qinhuangdao (CN); and Bo Liang, Qinhuangdao (CN)
Assigned to YANSHAN UNIVERSITY, Qinhuangdao (CN)
Appl. No. 17/288,221
Filed by YANSHAN UNIVERSITY, Qinhuangdao (CN)
PCT Filed May 7, 2020, PCT No. PCT/CN2020/088863
§ 371(c)(1), (2) Date Apr. 23, 2021,
PCT Pub. No. WO2021/184505, PCT Pub. Date Sep. 23, 2021.
Claims priority of application No. 202010201908.4 (CN), filed on Mar. 20, 2020.
Prior Publication US 2022/0305668 A1, Sep. 29, 2022
Int. Cl. B25J 15/00 (2006.01); B25J 9/16 (2006.01); B25J 15/10 (2006.01); B25J 15/12 (2006.01)
CPC B25J 15/0009 (2013.01) [B25J 9/1605 (2013.01); B25J 15/10 (2013.01); B25J 15/12 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A consistency control method of a soft joint gripper based on 4D printing, wherein the consistency control method of a soft joint gripper based on 4D printing is applied to a soft joint gripper based on 4D printing, wherein the soft joint gripper based on 4D printing, comprising:
a palm body and five soft finger units connected to the palm body, wherein:
each soft finger unit is provided with two soft finger joints and two finger bones;
the finger bones are made of 3D printing resin;
the soft finger joints are two symmetrical double-layer thin-film soft finger joint actuators;
the double-layer thin-film soft finger joint actuators are made of a 4D printing liquid crystal elastomer and a polyimide electrothermal film, and the bending angle of each double-layer thin-film soft finger joint actuator is changed by energization or heating stimulation; and
at least one double-layer film soft finger joint actuator is used to control the corresponding soft finger unit to perform reversible bending motion;
and the consistency control method of a soft joint gripper based on 4D printing comprises:
acquiring the bending angle of the soft finger joint and the rotation angle of the finger bone;
establishing a soft finger joint dynamic model and a finger bone dynamic model according to the bending angle of the soft finger joint and the rotation angle of the finger bone, respectively;
under a local coordinate system, determining the soft finger joint centroid positions and the soft finger joint centroid velocities of any two soft finger joints according to the soft finger joint dynamic model;
under a global coordinate system, determining the finger bone centroid positions and the finger bone centroid velocities of any two finger bones according to the finger bone dynamic model;
determining the soft finger joint kinetic energy and the soft finger joint potential energy according to the soft finger joint centroid position and the soft finger joint centroid velocity;
determining the finger bone kinetic energy and the finger bone potential energy according to the finger bone centroid position and the finger bone centroid velocity;
determining the dynamic model of bending angles of five soft finger units with respect to the soft finger joints according to the soft finger joint kinetic energy and the soft finger joint potential energy;
taking the dynamic model of bending angles of five soft finger units with respect to the soft finger joints as a control target to determine a consistency control protocol of a soft finger unit; and
controlling the soft finger unit to perform reversible bending motion according to the consistency control protocol of the soft finger unit.