Design And Performance Of Pneumatic Soft Tentacle Robot

Soft robot has the characteristics of large deformation and large bending,and its motion form and performance mainly depend on the driver.The soft robot has the following types of actuators: fluid elastic drive type(FEA),string tendon driven type(TDA),shape memory alloy driven type(SMA),pneumatic artificial muscle driven type(PAM),electroactive polymer driven type.(EAPs).The soft driver designed in this thesis is pneumatic type,which is chosen because of its small size,large power/weight ratio,low cost,safe and reliable and other advantages.In this thesis,a new type of pneumatic muscle is established based on corrugated woven mesh,and the weaving principle of the new woven mesh is analyzed.The inflating dynamic model of the new pneumatic muscle was studied,and the inflating experiment was carried out on the new pneumatic muscle.The relationship between the inflating pressure and the deformation length and radial expansion diameter of the muscle was studied,and the effect of the inflating pressure on the stiffness of the new pneumatic muscle was studied.In this thesis,two different software driver modules are designed based on the pneumatic muscle,and the inflatable bending principle of the two software driver modules is analyzed.The dynamic model and kinematics model of two driving modules are analyzed.In order to verify the accuracy of the software driver module,a pneumatic test platform was built to test the relationship between the air pressure and the bending Angle and deformation length of the software actuator.The software capture gripper consists of a software driver based on a new pneumatic muscle.The whole is mainly composed of three parts,each section has three controller channels for independent control.The first two sections are arranged by six pneumatic muscles in a regular hexagon,and two adjacent pneumatic muscles form a group to control the airway.The last section consists of three pneumatic muscles arranged in equilateral triangles,each of which is individually controlled so that any bending in the spatial position can be achieved.Because the tentacle-shaped robot designed in this thesis has the characteristics of large deformation,the traditional kinematic model based on the fixed curvature hypothesis has certain adaptability under the small bending deformation,but it has no adaptability under such large bending deformation conditions.This thesis proposes a general kinematic model based on curve theory for arbitrary deformation.Through Frenet formula,the change between the curvature and torsion of the movement curve of the soft robot can be described.In the establishment of the dynamic model,the strain energy density of the silica gel material is established by using the yeoh model,and the relationship between the inflation pressure and the bending length of the soft gripper is established by using the HagenPoiseuille equation and the energy conservation theory,and the end force balance of the software robot is established.The relationship between the pressure at the end bending angle.Compare the established model with simulation results and experimental data.Finally,the bending test experiment and the gripping motion experiment were carried out.The maximum elongation of the new pneumatic muscle designed in this thesis can reach 225%.Two flexible actuators based on this pneumatic muscle design enable bending in any direction in three dimensions,soft-based tentacle robots based on these two flexible actuators enable functions such as grabbing and obstacle avoidance.Establishing the strain energy density of silica gel material using yeoh model in kinematics modeling,using the Hagen-Poiseuille equation to establish the relationship between air pressure and muscle deformation.Finally,the kinematics model of pneumatic muscle and software driver is established based on the principle of energy conservation.