Research On Design Modelling And Application Of Typical Pneumatic Soft Actuators

Soft robot,belonging to continuum bionic robot,has developed in an emerging field in recent years.It can cope with difficult situations where space is scarce and conditions are complex to predict by deforming proactively.At the same time,adapting to the surrounding obstacles,it can reduce damage caused by possible collision and danger to the surrounding environment by deforming passively.Soft actuator is an indispensable section of soft robot as a mechanism of actuation.The research on theory and related technologies of soft actuators will promote the design and application of soft robot.This paper studies modelling methods of three typical soft actuators.A mathematical model of fiber radial constraint for cylindrical soft actuators is established,which proves that the one-direction radial winding would cause the axial rotation of soft actuator,while the two-direction radial winding would eliminate the axial rotation.The kinematics of soft actuator is established according to piecewise constant curvature model.The kinematics of multi-chamber Pneu Nets and singlechamber unilaterally restrained soft actuator is described.A single-chamber unilaterally restrained soft actuator is designed and the mold is manufactured by using 3D-Printing technology.A nylon material is applied as strain limiting layer so that the soft actuator bending to one side when air is pumped into the actuator.The Kevlar fibers is winding around the outer of the soft actuators to avoid excessive expansion of the chamber.A pneumatic experiment platform for soft actuator is built and the air scheme is designed.The pressure in the air path is measured by the pressure sensor,and the bending angle of soft actuator is recorded by the bending angle sensor.Abaqus is used to simulate the factors that affect deformation of soft actuators.At the same time,the bending factors,loading factors and constraint factors of the soft actuator are verified by experiments.Unilateral limited soft actuators are used to build rehabilitation gloves system.The sizes and motion angles of human fingers are analyzed to help design the system.The graphical interface developed by Matlab transforms instructions to the Arduino controller to drive the electromagnetic relay,solenoid valve and air pump.The motion control of rehabilitation gloves is realized by using s EMG sensors to capture the electrical signals of human body.