Developing a gripper with accurate grasping and positioning tasks has been a
daunting challenge in the assembly industry. To meet these requirements, this thesis
aims to develop two new types of compliant grippers. The first gripper with an
asymmetrical structure is capable of integrating displacement sensors. The second
gripper with a symmetrical structure is served for assembly. The hypothesized
grasping objects are small-sized cylinders as the shaft of the vibration motor used in
mobile phones or electronic devices ( 0.6mm×10mm).
In the first part, a displacement sensor for self-identifying the stroke of an
asymmetric compliant gripper is analyzed and optimized. Strain gauges are placed in
the flexible beams of the gripper and turn it into the displacement sensor with a
resolution of micrometers. In addition, static and dynamic equations of the gripper
are built via the pseudo-rigid-body model (PRBM) and Lagrange’s principle. To
increase the stiffness and frequency, silicone rubber is filled the open cavities of the
gripper. Taguchi-coupled teaching learning-based optimization (HTLBO) method is
formulated to solve the multi-response optimization for the gripper. Initial
populations for the HTLBO are generated using the Taguchi method (TM). The
weight factor (WF) for each fitness function is properly computed. The efficiency of
the proposed method is superior to other optimizers. The results determined that the
displacement is 1924.15 µm and the frequency is 170.45 Hz.
In the second part, a symmetric compliant gripper consisting of two symmetrical
jaws is designed for the assembly industry. The kinematic and dynamic models are
analyzed via PRBM and the Lagrange method. An intelligent computational
technique, adaptive network-based fuzzy inference system-coupled Jaya algorithm,
is proposed to improve the output responses of the gripper. The WF of each cost
function is computed. The results achieved a displacement of 3260 µm. Besides, the
frequency was 61.9 Hz. Physical experiments are implemented to evaluate the
effectiveness of both compliant grippers. The experimental results are relatively
agreed with the theoretical results.