Pneumatic bio-soft robot module: Structure, elongation and experiment

Bao Guanjun, Yao Pengfei, Xu Zonggui, Li Kun, Wang Zhiheng, Zhang Libin, Yang Qinghua


Soft robotics, often taking inspirations from biomimetics, is an exciting novel research field and has great capability to work with creatures. A new type of bio-soft robot inspired by elephant trunk and octopus was proposed, which has a promising application in robotic agricultural harvesting. The two modularized structures, basal segment and caudal segment, were elaborated in detail. They both have three side chambers and one central chamber, which are reinforced by springs for better stretch performance in axial direction without radial expansion. All the chambers can act as drivers when inflated with compressed air. More importantly, the central chamber was designed for regulating the stiffness of the robot module as needed in application. The primary static model for axial elongation was established for the fundamental analysis of the bio-soft robot module’s features, such as iso-force, isobaric and isometric characteristics. Simulation and experimental results showed that the motion of the proposed bio-soft module has approximate linearity in iso-force and isobaric conditions, and strict linearity in isometric condition.
Keywords: bio-soft robot, pneumatic muscle actuator, static model, harvesting robot
DOI: 10.3965/j.ijabe.20171002.2909

Citation: Bao G J, Yao P F, Xu Z G, Li K, Wang Z H, Zhang L B, et al. Pneumatic bio-soft robot module: Structure, elongation and experiment. Int J Agric & Biol Eng, 2017; 10(2): 114–122.


bio-soft robot, pneumatic muscle actuator, static model, harvesting robot


Daniela R, Michael T. Design, fabrication and control of soft robots. Nature, 2015; 512(7553): 467–475.

Fumiya I, Cecilia L. Soft robotics: challenges and perspectives. Procedia Computer Science, 2011; 7(29): 99–102.

Elango N, Faudzi A M. A review article: investigations on soft materials for soft robot manipulations. International Journal of Advanced Manufacturing Technology, 2015; 80(5-8): 1027–1037.

Villoslada A, Flores A, Copaci D, Blanco D, Moreno L. High-displacement flexible shape memory alloy actuator for soft wearable robots. Robotics and Autonomous Systems, 2015; 73SI: 91–101.

Mao S X, Dong E B, Jin H, Xu M, Zhang S W, Yang J, Low K. Gait study and pattern generation of a starfish-like soft robot with flexible rays actuated by SMAs. Journal of Bionic Engineering, 2014; 11(3): 400–411.

Mutlu R, Alici G, Xiang X C, Li W H. An active-compliant micro-stage based on EAP artificial muscles. Proceedings of 2014 IEEE/ASME International Conference on Advanced Intelligent Mechatronics, Besacon, France, 2014; pp. 611–616.

Hannan M, Walker I D. Analysis and experiments with an elephant’s trunk robot. Advanced Robot, 2001; 15(8): 847–858.

Hannan M, Walker I D. Kinematics and the implementation of an elephant’s trunk manipulator and other continuum style robots. Journal of Robot System, 2003; 20(2): 45–63.

Shao T F, Zhang L B, Du M Y, Bao G J, Yang Q H. Fruit harvesting continuum manipulator inspired by elephant trunk. Int J Agric & Biol Eng, 2015; 8(1): 57–63.

Li T, Nakajima K, Kuba M, Gutnick T, Hochner B, Pfeifer R. From the octopus to soft robots control: an octopus inspired behavior control architecture for soft robots. Vie Et Milieu, 2013; 61(4): 211–217.

Nakajima K, Hauser H, Li T, Pfeifer R. Information processing via physical soft body. Nature Scientific Report, 2015; 5(13): 10487.

Otake M, Kagami Y, Inaba M, Inoue H. Motion design of a starfish-shaped gel robot made of electro-active polymer gel. Robot Autonomous Systems. 2002; 40(2-3): 185–191.

Jin H, Dong E B, Mao S X, Xu M, Yang J. Locomotion modeling of an actinomorphic soft robot actuated by SMA springs. Proceedings of IEEE International Conference on Robotics & Biomimetics, Bali, Indonesia, 2014; pp.21–26.

Suzumori K, Endo S, Kanda T, Kato N, Suzuki H. A bending pneumatic rubber actuator realizing soft-bodied manta swimming robot. Proceedings of International Conference on Robotics and Automation, Roma, Italy, 2007; pp.4975–4980.

Cao Y, Bi S S, Cai Y R, Wang Y L. Applying central pattern generators to control the robotfish with oscillating pectoral fins. Industrial Robot: An International Journal, 2015; 42(5): 392–405.

Pfeifer R, Lungarella M, Iida F. The challenges ahead for bio-inspired soft robotics. Communications of the Acm, 2012; 55(11): 76–87.

Caldwell D G, Medrano-Cerda G A, Goodwin M J. Braided pneumatic actuator control of a multi-jointed manipulator. Proceedings of IEEE International Conference on Systems, Man and Cybernetics Proceedings, Le Touquet, France, 1993; pp. 423–428.

Nuchkrua T, Leephakpreeda T. Fuzzy self-tuning PID control of hydrogen-driven pneumatic artificial muscle actuator. Journal of Bionic Engineering, 2013; 10(3): 329–340.

Suzumori K, Iikura S, Tanaka H. Flexible microactuator for miniature robots. Proceedings of IEEE Micro Electro Mechanical Systems Conference, Nara, Japan, 1991; pp. 204–209.

Yang Q H, Zhang L B, Bao G J, Ruan J. Research on novel flexible pneumatic actuator FPA. Proceedings of IEEE Conference on Robotics, Automation and Mechatronics, 2004; pp. 385–389.

Zhang R X, Wang H S, Chen W D, Wang X Z. Motion analysis and experimental study of a cable-driven soft surgical robot. Proceedings of IEEE International Conference on Cyber Technology in Automation, Shenyang, China, 2015; pp. 2085–2090.

Yang Q H, Jin Y D, Qian S M, Bao G J. Research on end-effector of apple picking based on new flexible pneumatic actuator. Transactions of the CSAM, 2010; 41(9): 154–158. (in Chinese)

Zhang L B, Wang Y, Yang Q H, Bao G J, Gao F. Kinematics and trajectory planning of a cucumber harvesting robot manipulator. Int J Agric & Biol Eng, 2009; 2(1): 1–7.

Shao T F, Zhang L B, Du M Y, Bao G J, Yang Q H. Fruit harvesting continuum manipulator inspired by elephant trunk. Int J Agric & Biol Eng, 2015; 8(1): 57–63.

Galloway K C, Becker K P, Phillips B, J Kirby, Licht S. Soft robotic grippers for biological sampling on deep reefs. Soft Robotics, 2016; 3(1): 23–33.

Niiyama R, Sun X, Sung C, An B, Rus D, Kim S. Pouch motors: printable soft actuators integrated with computational design. Soft Robotics, 2015; 2(2): 59–70.

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