| Soft robots have received extensive attention in the fields of medical treatment,detection,and rescue due to their strong flexibility and greater degrees of freedom.Compared with traditional rigid robots,soft robots can change different shapes through active deformation to make them more adaptable to the environment;they can simulate the movement of natural creatures better and complete many environment-explore that humans cannot.As an important branch of soft robots,the study of pneumatic soft robots has been favored by researchers.However,the types of existing pneumatic soft drivers are fewer,and some drivers have problems in complicated manufacturing process,general driving performance,small load,and high control-requirements.Responded to the above problems,designed a pneumatic soft drive based on the origami structure using the characteristics of large folding ratio and fast transformation of the origami structure,two kinds of soft robots are developed based on this soft-driving.The main contents are as follows:In order to improve the driving performance of the pneumatic soft driver,the origami structure is used in the design of the strain layer of the driver to take advantage of the large folding ratio of the origami structure.Increase the amount of strain of the strained layer.The design and preparation method of pneumatic soft-driving are based on origami structure is given.By the stress-strain relationship of the strain layer and the geometric deformation of the drive are analyzed,and the analysis shows that the bending angle of the driver is proportional to the elongation of the strain layer,which shows that using the origami structure as the strain layer can improve the bending performance of the driver.In order to analyze the driving-performance of the drive and the impact of its structural parameters on the driving-performance of the drive,the mechanical model and kinematics model of origami pneumatic driver are established,Thus,the relationship between the output force,bending angle and input air pressure at the end of the driver is obtained,Using the model,the position of the end point and the attitude of the actuator are analyzed,An experimental platform was built to test the end output force and bending angle of the driver under different air pressures.The experimental results show that the relationship between the output force of the end of the driver and the input air pressure can be approximately linear.When the input air pressure is 0.1Mpa,the output force of the end can reach 9N;the relationship between the bending angle of the driver and the input air pressure is approximately linear segment Function,when the input air pressure is 0.05 Mpa,the bending angle can reach 250 degrees;the experimental data is in good agreement with the model,which proves that the model established has certain reliability.It shows that the model is accurate.A pneumatic soft gripper is designed by using origami-type pneumatic soft driver,and its automatic gripping function is realized.The soft gripper is composed of four origami-type soft drives and a fixture.Under the action of air pressure,the four drives bend simultaneously to grab the target.Carry its soft gripper on the end of the mechanical arm for experimental testing.The experimental results show that: in the gripping force experiment,when the input air pressure is 0.1Mpa,the maximum gripping force is 11.9N;in the mobile gripping experiment,the weight cannot exceed Objects with 2kg objects can be grasped stably,and objects with a weight of 2 to 3.5kg can be grasped adaptively,it shows that the designed soft gripper has better grasping performance.Using laser matrix positioning technology to design the automatic grabbing scheme,the soft gripper can realize the automatic grabbing function for the objects with different sizes,complex surfaces and different hardness,such as water cup,pear,dragon fruit,banana and tofu,which shows that the automatic grabbing scheme has certain advantages.A new type of soft crawling robot was designed using the origami-type pneumatic soft driver to imitate the motion law of inchworm.The robot is composed of a torso and feet,and a drive is used to simulate the bending movement of the torso and the design of the difference between the frictional force of the front and rear feet to realize the crawling movement.Combined with the kinematic model of the drive,the relationship between the robot's step distance and the input air pressure was derived,and the motion control parameters were given and the motion experiment was carried out.The experimental results show that the moving distance of the soft crawling robot in a single period is 25.1mm and the average moving speed is 13.9mm/s,which verifies the feasibility of the soft crawling robot in imitate the inchworm and the feasibility of the application of the origami pneumatic soft actuator in the field of crawling robot. |
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