Optimization Of Pneumatic Soft Actuator

The robotic gripper is an important part of the interaction between the robot and the environment,which directly affects the intelligence level of the robot.The end effector with automatic grippers is often used in assembly,sorting and other occasions.Traditional actuators have shortcomings such as large weight,high rigidity,damage to the surface of the object,and poor environmental interaction adaptability,making it difficult to adapt to complex environments.As the speed of new products continues to accelerate,the requirements for the versatility of robots are also increasing.The soft actuator is highly adaptable,easy to implement complex movements,and can safely perform human-computer interaction.It has broad prospects in the fields of industry,medical,and field operations.In this article,a new type of pneumatic soft actuator with isosceles trapezoidal air chambers is designed and made according to the operating principle of s PN soft actuator.The gripping performance of the soft actuator was optimized by orthogonal experiments,and a PVDF flexible sensor was made to measure the gripping force of the soft manipulator.The main research contents are as follows:We analyzed the operating principle of the s PN soft actuator.A new pneumatic actuator with isosceles trapezoidal chambers was proposed.The volume of each isosceles trapezoidal chamber is equal to the traditional rectangular chamber.For two different chamber types,we have established mathematical models to prove that the soft actuator deformability of the soft actuatoe with isosceles trapezoidal chambers is greater than the rectangular chambers under the same pressure.Increasing the number of chambers allowed more force to act on bending,and reduced the loss of force that expands in the radial direction.Reduce the amount of materials.We have prepared two kinds of PDMS with different different mechanical properties to make soft actuators,so that the main part of the soft actuator has only PDMS as hyperelastic material.The three-dimensional Yeoh model of hyperelastic materials was used to describe the nonlinear characteristics of PDMS,and the parameters of the Yeoh model were obtained through uniaxial tensile tests.A soft actuator finite element simulation model is established for CAE solution and post-processing.The optimal location of the inextensible layer was determined by finite element simulation.The orthogonal test method was used to arrange the finite element simulation parameters,and finally the optimal size parameters of the soft actuator were obtained,and the soft actuator with the minimum bending radius and the best stiffness was obtained.Make a soft actuator and verify it experimentally.Based on the basic theory of piezoelectricity,we made a PVDF flexible sensor.The PVDF film is equivalent to a charge equivalent circuit in which a charge source and a capacitor are connected in parallel,a preamplifier circuit is designed,and the signal is measured using the NI-9234 data acquisition board.Butterworth 4th-order low-pass filtering was used for signal denoising.The experimental results proved that the PVDF piezoelectric sensor can be used to measure the gripping force of soft actuators.