Purpose - The paper seeks to present a new generation of torque-controlled light-weight robots (LWR) developed at the Institute of Robotics and Mechatronics of the German Aerospace Center.Design methodology approach - An integrated mechatronic design approach for LWR is presented. Owing to the partially unknown properties of the environment, robustness of planning and control with respect to environmental variations is crucial. Robustness is achieved in this context through sensor redundancy and passivity-based control. In the DLR root concept, joint torque sensing plays a central role.Findings - In order to act in unstructured environments and interact with humans, the robots have design features and control software functionalities which distinguish them from classical robots, such as: load-to-weight ratio of 1:1, torque sensing in the joints, active vibration damping, sensitive collision detection, compliant control on joint and Cartesian level.Practical implications - The DLR robots are excellent research platforms for experimentation of advanced robotics algorithms. Space and medical robotics are further areas for which these robots were designed and hopefully will be applied within the next years. Potential industrial application fields are the fast automatic assembly as well as manufacturing activities done in cooperation with humans (industrial robot assistant). The described functionalities are of course highly relevant also for the potentially huge market of service robotics. The LWR technology was transferred to KUKA Roboter GmbH, which will bring the first arms on the market in the near future.Originality value - This paper introduces a new type of LWR with torque sensing in each joint and describes a consistent approach for using these sensors for manipulation in human environments. To the best of one's knowledge, the first systematic experimental evaluation of possible injuries during robot-human crashes using standardized testing facilities is presented.
Purpose - The purpose of this paper is to review recent developments in exoskeletons and robotic prosthetics.Design methodology approach - This paper first describes a number of recently developed exoskeletons for military, civil and medical applications. It then discusses robotic prosthetics and concludes with a brief consideration of progress in brain-computer interface (BCI) technology.Findings - Robotic exoskeletons are the topic of a major research effort, much being funded by the US military, and aims to impart superhuman strength to the wearer. Japanese research is also well advanced and concerns a range of non-military applications, including strength enhancement and medical rehabilitation. Some products have recently been commercialised. There has also been significant progress in the development of robotic prosthetic limbs, a topic which is also attracting support from the US military. A key aim is the development of thought-controlled prosthetics which will arise from advances in BCI technology.Originality value - This paper provides a detailed review of the latest developments in exoskeletons and robotic prosthetics.
Purpose – This article aims to provide details of recent robotic exoskeleton developments and applications. Design/methodology/approach – Following an introduction, this article first considers some of the technological issues associated with an exoskeleton design. It then discusses military developments, industrial load-carrying applications and uses in healthcare. Progress in thought-controlled exoskeletons is discussed briefly, and finally, concluding comments are drawn. Findings – This article shows that, while military interests continue, the dominant application is to restore or enhance mobility to individuals suffering from disabilities or injuries. An emerging use is to increase the strength and endurance of industrial workers. The majority are lower-limb devices, although some full-body exoskeletons have been developed, and most rely on battery-powered electric motors to create motion. Reflecting the anticipated growth in applications, exoskeletons are now available from, or under development by, a growing number of commercial organisations. Originality/value – This provides an insight into the latest developments in robotic exoskeletons and their applications.
Purpose - The purpose of this paper is to extract lessons learned from the Fukushima-Daiichi accident, caused by a big earthquake and a huge tsunami, which occurred on 11 March 2011.Design methodology approach - Lessons learned are extracted after summarizing emergency response by robots to the Fukushima-Daiichi accident.Findings - Many lessons had been learned from the experiences on robots' emergency response to the accident; organization and operation scheme, and systemization were major lessons learned.Practical implications - Unmanned constructive heavy machines and robots donated from the USA or imported from Sweden did reconnaissance work and cleaning up of rubble outside of buildings. Quince and JAEA-3 were deployed for reconnaissance inside buildings.Social implications - The Japanese nuclear disaster response robotics developed after Japan Conversion Corporation's critical accident occurred in 1999, could not work when the Fukushima-Daiichi accident occurred on 11 March 2011.Originality value - The paper emphasizes the importance of establishing emergency response schemes when a nuclear disaster occurs.
Purpose In this research, the authors established a hierarchical motion planner for quadruped locomotion, which enables a parallel wheel-quadruped robot, the “BIT-NAZA” robot, to traverse rough three-dimensional (3-D) terrain. Design/methodology/approach Presented is a novel wheel-quadruped mobile robot with parallel driving mechanisms and based on the Stewart six degrees of freedom (6-DOF) platform. The task for traversing rough terrain is decomposed into two prospects: one is the configuration selection in terms of a local foothold cost map, in which the kinematic feasibility of parallel mechanism and terrain features are satisfied in heuristic search planning, and the other one is a whole-body controller to complete smooth and continuous motion transitions. Findings A fan-shaped foot search region focuses on footholds with a strong possibility of becoming foot placement, simplifying computation complexity. A receding horizon avoids kinematic deadlock during the search process and improves robot adaptation. Research limitations/implications Both simulation and experimental results validated the proposed scenario available and appropriate for quadruped locomotion to traverse challenging 3-D terrains. Originality/value This paper analyzes kinematic workspace for a parallel robot with 6-DOF Stewart mechanism on both body and foot. A fan-shaped foot search region enhances computation efficiency. Receding horizon broadens the preview search to decrease the possibility of deadlock minima resulting from terrain variation.
Purpose The purpose of this study is to develop a new positioning method for remotely operated vehicle (ROV) in the nuclear power plant. The ROV of the nuclear power plant is developed to inspect the reactor cavity pools, the component pools and spent-fuel storage pools. To enhance the operational safety, the ability of localizing the ROV is indispensable. Design/methodology/approach Therefore, the positioning method is proposed based on the MEMS inertial measurement unit and mechanical scanning sonar in this paper. Firstly, the ROV model and on board sensors are introduced in detail. Then the sensor-based Kalman filter is deduced for attitude estimation. After that, the positioning method is proposed that divided into static positioning and dynamic positioning. The improved iterative closest point-Kalman filter is deduced to estimate the global position by the whole circle scanning sonar data in static, and the relative positioning method is proposed by the small scale scanning sonar data in dynamic. Findings The performance of the proposed method is verified by comparing with the visual positioning system. Finally, the effectiveness of the proposed method is proved by the experiment in the reactor simulation pool of the Daya Bay Nuclear Power Plant. Originality/value The research content of this manuscript is aimed at the specific application needs of nuclear power plants and has high theoretical significance and application value.
Purpose Lower extremity exoskeletons have drawn much attention recently due to their potential ability to help the stroke and spinal cord injury patients to regain the ability of walking. However, the balance of the human-exoskeleton system (HES) remains a big challenge. Usually, patients use crutches to keep balance when they wear exoskeleton. However, the balance depends greatly on the patient's balance ability and will be inevitably poor occasionally, which often causes the landing in advance of HES. The purpose of this paper is to propose a real-time stepping gait trajectory planning method based on the hip height variation of the swing leg to solve the problem. Design/methodology/approach The hip height of the swing leg was analyzed and measured. The simulation with MATLAB and the experimental test with the prototype of the proposed gait were conducted to verify its feasibility. Findings With the proposed method, HES can achieve successful step even when the balance kept by crutches is poor. Research limitations/implications Instead of actively avoiding the poor balance due to the instability caused by gravity, the method just modifies the stepping gait passively to avoid the landing in advance when the poor balance appears. In addition, it may not work well when the balance is too poor. Moreover, the proposed gait is just used in the initial stage of rehabilitation training. Besides, the step length of the gait must be limited for comfort. Originality/value A real-time stepping gait trajectory planning method based on the hip height variation of the swing leg is first proposed and its feasibility to avoid the landing in advance when the balance kept by the crutches is poor has been preliminary verified.
Purpose Manipulators are often subjected to joint flexibility caused by various causes in industrial applications, such as shaft windup, harmonic drives and bearing deformation. However, many industrial robots are only equipped with motor-side encoders because link-side encoders and torque transducers are expensive. Because of joint flexibility and resulted slow response rate, control performance of these manipulators is very limited. Based on this, the purpose of this paper is to use easy-to-install and cheap accelerometers to improve control performance of such manipulators. Design/methodology/approach First, a novel tip-acceleration feedback method is proposed to avoid amplifications of approximation errors caused by inversion of the Jacobian matrix. Then, a new control scheme, consisting an artificial neural network, a proportional-derivative (PD) controller and a reference model, is proposed to track motor-side position and suppress link-side vibration. Findings By using the proposed tip-acceleration feedback method, each link’s vibration can be suppressed correlatively. Through the networks, smaller motor-side tracking errors can be obtained and unknown dynamics can be compensated. Tracking and convergence performance of the network-based system can be improved by using the additional PD controller. Originality/value The originality is based on using accelerometers to improve link-side vibration suppression and control performance of flexible-joint manipulators. The previously used methods need expensive link-side sensors or accurate robot model, which is unavailable for many industrial robots only equipped with motor-side encoders. The report proposed a novel acceleration feedback method and used networks to solve such problems.
Purpose In the vast majority of the individual robot installations, the robot arm is just one piece of a complex puzzle of components, such as grippers, jigs or external axis, that together compose an industrial robotic cell. The success of such installations is very dependent not only on the selection of such components but also on the layout and design of the final robotic cell, which are the main tasks of the system integrators. Consequently, successful robot installations are often empirical tasks owing to the high number of experimental combinations that could lead to exhaustive and time-consuming testing approaches. Design/methodology/approach A newly developed optimized technique to deal with automatic planning and design of robotic systems is proposed and tested in this paper. Findings The application of a genetic-based algorithm achieved optimal results in short time frames and improved the design of robotic work cells. Here, the authors show that a multi-layer optimization approach, which can be validated using a robotic tool, is able to help with the design of robotic systems. Practical implications The usage of the proposed approach can be valuable to industrial corporations, as it allows for improved workflows, maximization of available robotic operations and improvement of efficiency. Originality/value To date, robotic solutions lack flexibility to cope with the demanding industrial environments. The results presented here formalize a new flexible and modular approach, which can provide optimal solutions throughout the different stages of design and execution control of any work cell.
Purpose This paper aims to address the collision problem between robot and the external environment (including human) in an unstructured situation. A new collision detection and torque optimization control method is proposed. Design/methodology/approach Firstly, when the collision appears, a second-order Taylor observer is proposed to estimate the residual value. Secondly, the band-pass filter is used to reduce the high-frequency torque modeling dynamic uncertainty. With the estimate information and the torque value, a variable impedance control approach is then synthesized to guarantee that the collision is avoided or the collision will be terminated with different contact models and positions. However, in terms of adaptive linear force error, the variation of the thickness of the boundary layer is controlled by the new proximity function. Findings Finally, the experimental results show the better performance of the proposed control method, realizing the force control during the collision process. Originality/value Origin approach and origin experiment.
Purpose This paper aims to provide details of recent developments in robots aimed at applications in the offshore oil and gas industries. Design/methodology/approach Following a short introduction, this first discusses developments to remotely operated vehicles (ROVs) and autonomous underwater vehicles (AUVs). It then describes the Total-sponsored Autonomous Robot for Gas and Oil Sites (ARGOS) robot challenge. This is followed by a discussion of the Offshore Robotics for Certification of Assets (ORCA) programme. Finally, brief concluding comments are drawn. Findings Subsea residency and other techniques are being developed that will enhance the availability and capabilities of AUVs and ROVs and reduce their operating costs. Mobile robots that can operate in harsh topside rig environments to monitor and detect hazards arose from ARGOS and are being developed further prior to commercialisation. Bringing together academics and users, the collaborative ORCA programme is making significant progress in the development of aerial, topside and underwater robotic and sensing technologies for rig asset inspection and maintenance. Originality/value This paper identifies and describes key development activities that will stimulate the use of robots by the offshore industries.
Purpose This paper aims to improve the performance of a two-camera robotic feedback system designed for automatic pick and place application by modifying its velocity profile during switching of control. Design/methodology/approach Cooperation of global and local vision sensors ensures visibility of the target for a two-camera robotic system. The master camera, monitoring the workspace, guides the robot such that image-based visual servoing (IBVS) by the eye-in-hand camera transcends its inherent shortcomings. A hybrid control law steers the robot until the system switches to IBVS in a region proven for its asymptotic stability and convergence through a qualitative overview of the scheme. Complementary gain factors can ensure a smooth transition in velocity during switching considering the versatility and range of the workspace. Findings The proposed strategy is verified through simulation studies and implemented on a 6-DOF industrial robot ABB IRB 1200 to validate the practicality of adaptive gain approach while switching in a hybrid visual feedback system. This approach can be extended to any control problem with uneven switching surfaces or coarse/fine controllers which are subjected to discrete time events. Practical implications In complex workspace where robots operate in parallel with other robots/humans and share workspaces, the supervisory control scheme ensures convergence. This study proves that hybrid control laws are more effective than conventional approaches in unstructured environments and visibility constraints can be overcome by the integration of multiple vision sensors. Originality/value The supervisory control is designed to combine the visual feedback data from eye-in-hand and eye-to-hand sensors. A gain adaptive approach smoothens the velocity characteristics of the end-effector while switching the control from master camera to the end-effector camera.
Purpose The purpose of this study is to design and manufacture a new remote center of motion (RCM) mechanism for use in laparoscopic surgical operations. In addition, obtaining the forward and inverse kinematic equations of the RCM mechanism and performing real-time position control with the Proportional–Integral–Derivative (PID) control method. Design/methodology/approach At the design stage, it is benefited from similar triangle rule. To obtain the kinematic equations in a simple way and facilitate control, two-fold displacement ratio is provided between the limbs where linear motion occurs. The rotation and displacement amounts required to move at the RCM point have been calculated by using the kinematic equations of the mechanism. Limb dimensions and motion limits are determined in the manner to avoid singularities and collisions. The x, y and z coordinates of the end effector have been defined as the reference point. Control of the mechanism was provided by PID control. To generate the user interface and control algorithm, MATLAB/Simulink real-time toolbox has been used. Four reference points were determined, control was performed and position error values were examined. MF634 Humusoft data acquisition card has been preferred to collect data from encoders. Findings A novel RCM mechanism has been designed and manufactured. Kinematic equations of this mechanism have been obtained. Position control of the cannula tip has been performed using PID control method for four different reference points. After settlement, maximum position error has been observed as 0.45 mm. Practical implications Structure of the designed mechanism is quite simple. Thus, costs are quite low. The operation area of the operator is widened by hanging the mechanism from the ceiling, so operational capability of health personnel is increasing. It helps to decrease the operation time and increase the success of the operation. Originality/value With this study, it is aimed to contribute to the literature by designing a new RCM mechanism. The rotation of the mechanism around the RCM point is provided by only one rotary motor, and the displacement of the RCM point in the vertical axis is provided by only one linear motor. The mechanism is also a surgical robot. The designed system is suitable for use in robot-assisted laparoscopic surgery in terms of maneuverability.
Purpose The power cable maintenance robot is an important equipment to ensure the reliable operation of high-voltage transmission (HVT) lines and is a useful exploration to achieve high-quality power transmission. In respond to a series of technical problems in the operation process, such as robot shaking, terminal positioning error, camera image blurred and visual servo control difficulty which caused by the influence of high altitude random wind load on the motion control of power maintenance robot. The purpose of this study is to minimizing the impact of wind loads on robot motion control on the high voltage transmission line, so as to obtain the sound motion performance. Design/methodology/approach This paper presents a robust stabilization control method for flexible wire power maintenance robot under wind load action, the coupling mathematical model between the flexible wire with the robot has been established, and the robot rolling model under wind load has also been established. According to the tilt sensor, the robot pendulum angle value can be obtained and fitted through sinusoidal function; the robot swing period and frequency under wind load action can be also obtained; the feedforward- and feedback-based robot closed-loop control system is also designed. Findings Through the online detection of wind load dection, so as to dynamic control the clamping force of the robot's dual-arm jaws, therefore, the robot robust stabilization control with different grades of wind load can be realized. Finally, the effectiveness and engineering practicability of the proposed algorithm are verified by simulation experiments and field operation experiments. Compared with the conventional proportional integral differential (PID) algorithm, this method can effectively suppress the influence of wind load on the robot robust stabilization motion control, and the robot posture detection operation control has been further optimized. Originality/value A robust stabilization control method for power robot under wind load is proposed. The coupling motion model of flexible HVT and robot is established. The mathematical relationship between the robot wind rolling angle and the wind force has been deduced, and the corresponding closed-loop control system with feedforward and feedback has also been designed. Through the design of robust stabilization control algorithm based on mixed sensitivity function, the effectiveness of the mixed sensitivity robust stabilization control algorithm is verified by simulation experiments in MATLAB environment. Compared with the traditional PID algorithm, this method can effectively suppress the influence of large-scale disturbance information represented by wind load on the robot motion control. The engineering practicability of the robot robust stabilization control algorithm is further verified by the robot live damper replacement operation under the field wind load, which further improves the robot operation efficiency and intelligence.
Purpose This paper aims to present a solution to dredging the irrigation canals using a robotic system. Considering the importance of irrigating water, the waste within the water canals should be avoided. Irrigation canals are artificial linear structures in the landscape that are used for transporting the water. One important problem in water transferring is the waste materials flow inside the water, and in some areas, they block the main stream, reducing the effective capacity of the canal. Among the waste materials, aquatic plants are grown on the surface of the canal that needs to be removed from the canal. This removal operation is conducted using chemical, biological, ecological and physical methods with complex supply systems. In addition, robotic systems are used as such complex systems. So, a robotic system is proposed to dredging the irrigation canals. The assumed robot was manufactured in AGRINS laboratory of Tehran University. Design/methodology/approach Design procedure, dynamic modelling and simulation of this robotic system are studied. To validate the system design before its construction, ADAMS software is used to perform simulations. Finally, performance evaluation of the dredger robot in the canal is studied based on the experimental data. Findings Results show that the design procedure has been correctly fitted to the real condition. Therefore, the designed robot could be easily used to dredging irrigation canals. Practical implications The assumed robot was manufactured in AGRINS laboratory of Tehran University. Originality/value Performing a dredging operation in the canals could be conducted by a new technique considering both free sides of the canal. Therefore, in this paper, a conceptual design of a 3-wheels stair dredger robot is numerically and experimentally studied.
Purpose This paper aims to provide details of recent research into robots capable of ascending vertical or near-vertical surfaces and to illustrate how the ability to climb is set to resolve a critical industrial need arising from the growth in renewable energy. Design/methodology/approach Following a short introduction, the first parts of this paper describe a selection of recent research activities that involve innovative concepts and designs. The second part discusses climbing robot developments aimed at the automated inspection, maintenance and repair of wind turbine blades. Brief concluding comments are drawn. Findings Robots that can ascend vertical or near-vertical surfaces are the topic of an extensive and technologically innovative research effort. Many developments take their inspiration from the climbing abilities of living creatures. Drones with the ability to adhere to and climb vertical surfaces are also being developed. Potential applications include inspection, surveillance and search and rescue. Climbing robots are poised to provide a solution to the need to de-man and reduce the cost of inspecting and maintaining composite wind turbine blades. Originality/value This provides an insight into recent innovations in climbing robot concepts and designs and shows how the ability to ascend vertical surfaces is being exploited in the robotic inspection, maintenance and repair of wind turbine blades.
Purpose The following paper is a “Q&A interview” conducted by Joanne Pransky of Industrial Robot Journal as a method to impart the combined technological, business and personal experience of a prominent, robotic industry engineer-turned entrepreneur regarding his pioneering efforts in the industrial robot industry and the commercialization and challenges of bringing robotic inventions to market. This paper aims to discuss these issues. Design/methodology/approach The interviewee is Brian Carlisle, President and Co-founder of Precise Automation, a robot manufacturer that specializes in collaborative robots. Carlisle discusses the highlights of his 40-year career that led to groundbreaking innovations in small parts assembly and handling robots, along with some of the challenges. He also shares his thoughts on the future of the industry. Findings Brian Carlisle received his BS and MS degrees in Mechanical Engineering from Stanford University. After Stanford, Carlisle and colleague Dr Bruce Shimano worked for Vicarm, a three-person company started by robotics pioneer Victor Scheinman. Vicarm was sold to Unimation and Carlisle became Unimation’s Director of R&D where he and his team developed the PUMA™ series of electric robots and grew sales from $0 to $40m in five years. In 1983, Carlisle and Shimano co-founded Adept Technology and as its CEO for 20 years, Carlisle grew Adept to over $100m in robot sales. In 2004, Carlisle co-founded with Shimano, Precise Automation, and is the President and CEO. Originality/value Brian Carlisle is a pioneer of the small parts assembly and handling robot. He was one of the key members of the team that developed the PUMA™ robot for Unimation. The PUMA™ robot was the watershed product that launched the assembly robot business in the USA and Europe. At Adept, he led the design of the first Direct Drive SCARA Robot and under his helm, Precise Automation introduced the first commercially available collaborative robots. Carlisle was President of the Robotic Industries Association for three years, is the recipient of the Joseph Engelberger Award for Leadership in Robotics, and an elected IEEE Fellow. He has served on the Board of the National Coalition for Advanced Manufacturing, the Boards of the National Center for Manufacturing Science, the Automation Forum of NEMA and is a founding member of the National Electronics Manufacturing Initiative. He holds multiple patents for robot designs.
Purpose This paper aims to imitate a cownose ray to develop a fish robot with paired flexible multi-fin-ray oscillating pectoral fins (OPFs) and control it to accomplish vivid stable 3-D motions using central pattern generators (CPGs) and fuzzy algorithm. Design/methodology/approach The cownose ray’s asymmetric sine-like oscillations were analyzed. Then a cownose-ray-like fish robot named Robo-ray was developed, which has paired flexible multi-fin-ray OPFs to actively control the fin shape and two tail fins to control the depth. To solve the problem of coordinated control for multi-degree-of-freedom Robo-ray, CPGs were adopted. An improved phase oscillator as a CPG unit with controlled amplitude, phase lag, smooth frequency transition and asymmetric oscillation characteristic was established. Furthermore, the CPG-fuzzy algorithm was developed for vivid stable 3-D motions. The open-loop speed control, the closed-loop control of depth and yaw were established. Findings The kinematic comparisons indicate that Robo-ray imitates the cownose ray realistically. The experimental results of closed-loop are obtained that the depth error of Robo-ray is less than ±100 mm and the course error is less than ±3°. Furthermore, the comprehensive experiments demonstrate that Robo-ray has high mobility, stability and robustness. Originality/value This research makes the fish robot with OPF propulsion closer to practical applications in complex underwater environment, for instance, ocean explorations, water quality monitoring and stealth military reconnaissance. In addition, Robo-ray can be taken as a scientific tool for better understanding of the hydrodynamics of OPF batoid.
Purpose The paper aims to improve the radiation-proof capability of the self-designed mobile robot with a 7-DOF manipulator, enabling the long-playing inspection and intervention under high-dose radiation environment. In this context, gamma-ray irradiation test for electronic components and specific hardness design have also been specifically presented and discussed. Design/methodology/approach The study’s hardness design mainly focuses on shielding protection, distance protection and time protection. Irradiation test is first carried out to investigate irradiation resistance of each electronic module. Then, modular deployment and shielding calculation are completed for the point-type nuclear accidents, respectively, to achieve a robust anti-radiation design scheme. Finally, the field experiment is conducted to validate system effectiveness and good mobility, and operational practices are acquired for the realization of time protection. Findings Coupled with modular redeployment and shielding design, irradiation results illustrate the effectiveness of robotic anti-radiation design. Meanwhile, experiences and reformed measures from the field exercise implement efficient operation and radiological time protection. Research limitations/implications Considering the huge risks of high-dose source exposure, the radiation-resistance of the overall system cannot be verified in the field experiment. Fortunately, irradiation test and modular shielding calculation are conducted as a minimal validation. Practical implications The proposed anti-radiation design methods and the irradiated results can be applied to many other nuclear vehicles and manipulators for the feasible multi-layer protection and excellent mobility. Originality/value A nuclear intervention robot with specific hardness design is presented in detail in this paper. Enlightened by the idea of shielding and distance protection, a large number of electronic modules with multiple types and structures are treated and compared in irradiation experiments, while modular redeployment and retrofitting are completed to reduce irradiated damages. To achieve the effect of time protection, mobility performance and operational practices are discussed and validated in the field experiment based on the mobile system.
Purpose The purpose of this paper is to solve the common problems of outer phenomenon and stress concentration among pneumatic networks soft actuators. Design/methodology/approach On the basis of imitating the caterpillar structure, the new soft actuator adopts the integral circular ladder structure instead of the traditional independent distributed structure as the air chamber. Through the comparison of several different structures, the parabolic in-wall curve is found to be fit for designing the optimal integrated chamber structure of the soft actuator. The curve function of each ladder chamber is computed based on the torque distribution model, aiming to decrease the terminal deformation. Meanwhile, the FEM analysis method is applied to establish the motion model of the integrated parabolic ladder soft actuator. The model’s accuracy, as well as structure’s deformation and stress, are verified. Findings Compared with the FEM data, the experimental data indicate that the new soft actuator has no obvious outer phenomenon, the maximum stress decreases and the stiffness increases. The new actuator is applied for designing a flexible gripper to grasp objects of different shapes and sizes. The gripper can grasp objects of 52.6 times its own mass. Practical implications The designed gripper is available for flexible production in various fields, such as capturing fruits of different sizes, soft foods or parts with complex shapes. Originality/value This paper proposes a new type soft actuator, which provides a solution for exploring the field of the soft robot. The problems of outer phenomenon and stress concentration are suppressed with pneumatic networks soft actuators.