As for the complex operational tasks in the unstructured environment with narrow workspace and numerous obstacles,the traditional robots cannot accomplish these mentioned complex operational tasks and meet the dexteri...As for the complex operational tasks in the unstructured environment with narrow workspace and numerous obstacles,the traditional robots cannot accomplish these mentioned complex operational tasks and meet the dexterity demands.The hyper-redundant bionic robots can complete complex tasks in the unstructured environments by simulating the motion characteristics of the elephant’s trunk and octopus tentacles.Compared with traditional robots,the hyper-redundant bionic robots can accomplish complex tasks because of their flexible structure.A hyper-redundant elephant’s trunk robot(HRETR)with an open structure is developed in this paper.The content includes mechanical structure design,kinematic analysis,virtual prototype simulation,control system design,and prototype building.This design is inspired by the flexible motion of an elephant’s trunk,which is expansible and is composed of six unit modules,namely,3UPS-PS parallel in series.First,the mechanical design of the HRETR is completed according to the motion characteristics of an elephant’s trunk and based on the principle of mechanical bionic design.After that,the backbone mode method is used to establish the kinematic model of the robot.The simulation software SolidWorks and ADAMS are combined to analyze the kinematic characteristics when the trajectory of the end moving platform of the robot is assigned.With the help of ANSYS,the static stiffness of each component and the whole robot is analyzed.On this basis,the materials of the weak parts of the mechanical structure and the hardware are selected reasonably.Next,the extensible structures of software and hardware control system are constructed according to the modular and hierarchical design criteria.Finally,the prototype is built and its performance is tested.The proposed research provides a method for the design and development for the hyper-redundant bionic robot.展开更多
This article describes a biologically inspired node generator for the path planning of serially connected hyper-redundant manipulators using probabilistic roadmap planners. The generator searches the configuration spa...This article describes a biologically inspired node generator for the path planning of serially connected hyper-redundant manipulators using probabilistic roadmap planners. The generator searches the configuration space surrounding existing nodes in the roadmap and uses a combination of random and deterministic search methods that emulate the behaviour of octopus limbs. The strategy consists of randomly mutating the states of the links near the end-effector, and mutating the states of the links near the base of the robot toward the states of the goal configuration. When combined with the small tree probabilistic roadmap planner, the method was successfully used to solve the narrow passage motion planning problem of a 17 degree-of-freedom manipulator.展开更多
Redundant or hyper-redundant mobile manipulator can give lots of assistance to astronauts in space station. The design and implementation of a hyper-redundant mobile manipulator system are described, which is composed...Redundant or hyper-redundant mobile manipulator can give lots of assistance to astronauts in space station. The design and implementation of a hyper-redundant mobile manipulator system are described, which is composed of an 8 DOF module robot and a 1 DOF motorized rail. Inverse kinematic resolution of the system is discussed and one simplified control method based on joint limit avoidance and configuration optimization is proposed. Simulation and experimental results are presented.展开更多
In this study,a hyper-redundant manipulator was designed for detection and searching in narrow spaces for aerospace and earthquake rescue applications.A forward kinematics equation for the hyper-redundant manipulator ...In this study,a hyper-redundant manipulator was designed for detection and searching in narrow spaces for aerospace and earthquake rescue applications.A forward kinematics equation for the hyper-redundant manipulator was derived using the homogeneous coordinate transformation method.Based on the modal function backbone curve method and the known path,an improved modal method for the backbone curves was proposed.First,the configuration of the backbone curve for the hyper-redundant manipulator was divided into two parts:a mode function curve segment of the mode function and a known path segment.By changing the discrete points along the known path,the backbone curve for the manipulator when it reached a specified path point was dynamically obtained,and then the joint positions of the manipulator were fitted to the main curve by dichotomy.Combined with engineering examples,simulation experiments were performed using the new algorithm to extract mathematical models for external narrow space environments.The experimental results showed that when using the new algorithm,the hyper-redundant manipulator could complete the tasks of passing through curved pipes and moving into narrow workspaces.The effectiveness of the algorithm was also proven by these experiments.展开更多
To reduce the risk of infection in medical personnel working in infectious-disease areas, we proposed ahyper-redundant mobile medical manipulator (HRMMM) to perform contact tasks in place of healthcare workers.A kinem...To reduce the risk of infection in medical personnel working in infectious-disease areas, we proposed ahyper-redundant mobile medical manipulator (HRMMM) to perform contact tasks in place of healthcare workers.A kinematics-based tracking algorithm was designed to obtain highly accurate pose tracking. A kinematic modelof the HRMMM was established and its global Jacobian matrix was deduced. An expression of the trackingerror based on the Rodrigues rotation formula was designed, and the relationship between tracking errors andgripper velocities was derived to ensure accurate object tracking. Considering the input constraints of the physicalsystem, a joint-constraint model of the HRMMM was established, and the variable-substitution method was usedto transform asymmetric constraints to symmetric constraints. All constraints were normalized by dividing bytheir maximum values. A hybrid controller based on pseudo-inverse (PI) and quadratic programming (QP) wasdesigned to satisfy the real-time motion-control requirements in medical events. The PI method was used whenthere was no input saturation, and the QP method was used when saturation occurred. A quadratic performanceindex was designed to ensure smooth switching between PI and QP. The simulation results showed that theHRMMM could approach the target pose with a smooth motion trajectory, while meeting different types of inputconstraints.展开更多
The design of space hyper-redundant robot with high dexterity is problem with great complexity. Taking the aim at robot product seriation and combination design, the combination design method of space hyper-redundant ...The design of space hyper-redundant robot with high dexterity is problem with great complexity. Taking the aim at robot product seriation and combination design, the combination design method of space hyper-redundant robot based on the omnidirectional unit arm of 3 degrees of freedom (d.o.f) is proposed in this paper. The kinematics model of this kind of robot is established through the equivalent mechanism model. On the basis of successful research on 3-d.o.f unit arm, the 7-d.o.f bionics arm redundant robot with double unit arm has been developed further.The content discussed in this paper is very important to the robot technology in future space station, nuclear industry andunderwater work on the sea floor.展开更多
A novel hyper-redundant manipulator named RT1 is designed and studied. The unique feature of RT1 is all degrees of freedom (DOF) are actuated with only one motor via special designed hinge bar universal joints. The me...A novel hyper-redundant manipulator named RT1 is designed and studied. The unique feature of RT1 is all degrees of freedom (DOF) are actuated with only one motor via special designed hinge bar universal joints. The mechanisms of RT1 are introduced in detail. Some experiments are carried out in order to test the movability and adaptability of the manipulator. RT1 is actuated by pulse string and acts discretely. The discrete working space of RT1 is described and the parameter optimization for kinematical redundancy resolution is studied also. The optimization criterion is altering the design parameter as little as possible during manipulator's motion from the initial position to the expected position. An optimization example is given that is realized with Matlab optimize tool-box.展开更多
A segmented hyper-redundant manipulator can perform complicated operation tasks in a confined space due to its high flexibility and dexterity. However, the trajectory planning in a narrow space and obstacles environme...A segmented hyper-redundant manipulator can perform complicated operation tasks in a confined space due to its high flexibility and dexterity. However, the trajectory planning in a narrow space and obstacles environment is very challenging for the manipulator. In this paper, we propose a geometry method to simultaneously plan the end-effector pose and manipulator’s configuration. Firstly, the geometries of each segment are described by an inscribed arc(IA) and a circumscribed arc(CA). Then,the whole kinematics chain is considered as an inscribed curve(IC) or a circumscribed curve(CC) which are composed of multiple IAs or CAs. Furthermore, the IC and CC of the manipulator are divided into multiple spatial single-arc and double-arc groups according to requirements. The pose-configuration simultaneous planning is realized by the spatial single-arc/double-arc modeling and joints angles solving. By numerical iteration, the spatial arcs’ parameters are determined according to desired pose and boundary condition of obstacle avoidance. The angles of joints are analytically solved when the above parameters are known. Finally, a narrow space detection task is simulated and experimented respectively. The results verify the proposed method.展开更多
Continuum manipulators(CM)are soft and flexible manipulators with large numbers of degrees of freedom and can perform complex tasks in an unstructured environment.However,their deformability and compliance can deviate...Continuum manipulators(CM)are soft and flexible manipulators with large numbers of degrees of freedom and can perform complex tasks in an unstructured environment.However,their deformability and compliance can deviate distal tip under uncertain external interactions.To address this challenge,a novel tension-based control scheme has been proposed to modulate the stiffness of a tendon-driven CM,reducing the tip position errors caused by uncertain external forces.To minimize the tip position error,a virtual spring is positioned between the deviated and the desired tip positions.The proposed algorithm corrects the manipulator deviated tip position,improving tension distribution and stiffness profile,resulting in higher stiffness and better performance.The corresponding task space stiffness and condition numbers are also computed under different cases,indicating the effectiveness of the tension control scheme in modulating the manipulator's stiffness.Experimental validation conducted on an in-house developed prototype confirms the practical feasibility of the proposed approach.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.51375288)Science and Technology Program of Guangdong Province of China(Grant No.2020ST004)+1 种基金Department of Education of Guangdong Province of China(Grant No.2017KZDXM036and Special Project for Science and Technology Innovation Team of Foshan City of China(Grant No.2018IT100052).
文摘As for the complex operational tasks in the unstructured environment with narrow workspace and numerous obstacles,the traditional robots cannot accomplish these mentioned complex operational tasks and meet the dexterity demands.The hyper-redundant bionic robots can complete complex tasks in the unstructured environments by simulating the motion characteristics of the elephant’s trunk and octopus tentacles.Compared with traditional robots,the hyper-redundant bionic robots can accomplish complex tasks because of their flexible structure.A hyper-redundant elephant’s trunk robot(HRETR)with an open structure is developed in this paper.The content includes mechanical structure design,kinematic analysis,virtual prototype simulation,control system design,and prototype building.This design is inspired by the flexible motion of an elephant’s trunk,which is expansible and is composed of six unit modules,namely,3UPS-PS parallel in series.First,the mechanical design of the HRETR is completed according to the motion characteristics of an elephant’s trunk and based on the principle of mechanical bionic design.After that,the backbone mode method is used to establish the kinematic model of the robot.The simulation software SolidWorks and ADAMS are combined to analyze the kinematic characteristics when the trajectory of the end moving platform of the robot is assigned.With the help of ANSYS,the static stiffness of each component and the whole robot is analyzed.On this basis,the materials of the weak parts of the mechanical structure and the hardware are selected reasonably.Next,the extensible structures of software and hardware control system are constructed according to the modular and hierarchical design criteria.Finally,the prototype is built and its performance is tested.The proposed research provides a method for the design and development for the hyper-redundant bionic robot.
文摘This article describes a biologically inspired node generator for the path planning of serially connected hyper-redundant manipulators using probabilistic roadmap planners. The generator searches the configuration space surrounding existing nodes in the roadmap and uses a combination of random and deterministic search methods that emulate the behaviour of octopus limbs. The strategy consists of randomly mutating the states of the links near the end-effector, and mutating the states of the links near the base of the robot toward the states of the goal configuration. When combined with the small tree probabilistic roadmap planner, the method was successfully used to solve the narrow passage motion planning problem of a 17 degree-of-freedom manipulator.
文摘Redundant or hyper-redundant mobile manipulator can give lots of assistance to astronauts in space station. The design and implementation of a hyper-redundant mobile manipulator system are described, which is composed of an 8 DOF module robot and a 1 DOF motorized rail. Inverse kinematic resolution of the system is discussed and one simplified control method based on joint limit avoidance and configuration optimization is proposed. Simulation and experimental results are presented.
基金The authors gratefully acknowledge the financial support provided by the National Key Research&Development Project of China(Grant No.2019YFB1311203).
文摘In this study,a hyper-redundant manipulator was designed for detection and searching in narrow spaces for aerospace and earthquake rescue applications.A forward kinematics equation for the hyper-redundant manipulator was derived using the homogeneous coordinate transformation method.Based on the modal function backbone curve method and the known path,an improved modal method for the backbone curves was proposed.First,the configuration of the backbone curve for the hyper-redundant manipulator was divided into two parts:a mode function curve segment of the mode function and a known path segment.By changing the discrete points along the known path,the backbone curve for the manipulator when it reached a specified path point was dynamically obtained,and then the joint positions of the manipulator were fitted to the main curve by dichotomy.Combined with engineering examples,simulation experiments were performed using the new algorithm to extract mathematical models for external narrow space environments.The experimental results showed that when using the new algorithm,the hyper-redundant manipulator could complete the tasks of passing through curved pipes and moving into narrow workspaces.The effectiveness of the algorithm was also proven by these experiments.
基金the National Natural Science Foundation of China(No.52175103)。
文摘To reduce the risk of infection in medical personnel working in infectious-disease areas, we proposed ahyper-redundant mobile medical manipulator (HRMMM) to perform contact tasks in place of healthcare workers.A kinematics-based tracking algorithm was designed to obtain highly accurate pose tracking. A kinematic modelof the HRMMM was established and its global Jacobian matrix was deduced. An expression of the trackingerror based on the Rodrigues rotation formula was designed, and the relationship between tracking errors andgripper velocities was derived to ensure accurate object tracking. Considering the input constraints of the physicalsystem, a joint-constraint model of the HRMMM was established, and the variable-substitution method was usedto transform asymmetric constraints to symmetric constraints. All constraints were normalized by dividing bytheir maximum values. A hybrid controller based on pseudo-inverse (PI) and quadratic programming (QP) wasdesigned to satisfy the real-time motion-control requirements in medical events. The PI method was used whenthere was no input saturation, and the QP method was used when saturation occurred. A quadratic performanceindex was designed to ensure smooth switching between PI and QP. The simulation results showed that theHRMMM could approach the target pose with a smooth motion trajectory, while meeting different types of inputconstraints.
文摘The design of space hyper-redundant robot with high dexterity is problem with great complexity. Taking the aim at robot product seriation and combination design, the combination design method of space hyper-redundant robot based on the omnidirectional unit arm of 3 degrees of freedom (d.o.f) is proposed in this paper. The kinematics model of this kind of robot is established through the equivalent mechanism model. On the basis of successful research on 3-d.o.f unit arm, the 7-d.o.f bionics arm redundant robot with double unit arm has been developed further.The content discussed in this paper is very important to the robot technology in future space station, nuclear industry andunderwater work on the sea floor.
文摘A novel hyper-redundant manipulator named RT1 is designed and studied. The unique feature of RT1 is all degrees of freedom (DOF) are actuated with only one motor via special designed hinge bar universal joints. The mechanisms of RT1 are introduced in detail. Some experiments are carried out in order to test the movability and adaptability of the manipulator. RT1 is actuated by pulse string and acts discretely. The discrete working space of RT1 is described and the parameter optimization for kinematical redundancy resolution is studied also. The optimization criterion is altering the design parameter as little as possible during manipulator's motion from the initial position to the expected position. An optimization example is given that is realized with Matlab optimize tool-box.
基金supported by the Key Research and Development Program of Guangdong Province(Grant No.2019B090915001)the National Key R&D Program of China(Grant No.2018YFB1304600)+1 种基金the National Natural Science Foundation of China(Grant No.61803125)the Basic Research Program of Shenzhen(Grant Nos.JCY20180507183610564,JCYJ20190806144416980,and JSGG20200103103401723)。
文摘A segmented hyper-redundant manipulator can perform complicated operation tasks in a confined space due to its high flexibility and dexterity. However, the trajectory planning in a narrow space and obstacles environment is very challenging for the manipulator. In this paper, we propose a geometry method to simultaneously plan the end-effector pose and manipulator’s configuration. Firstly, the geometries of each segment are described by an inscribed arc(IA) and a circumscribed arc(CA). Then,the whole kinematics chain is considered as an inscribed curve(IC) or a circumscribed curve(CC) which are composed of multiple IAs or CAs. Furthermore, the IC and CC of the manipulator are divided into multiple spatial single-arc and double-arc groups according to requirements. The pose-configuration simultaneous planning is realized by the spatial single-arc/double-arc modeling and joints angles solving. By numerical iteration, the spatial arcs’ parameters are determined according to desired pose and boundary condition of obstacle avoidance. The angles of joints are analytically solved when the above parameters are known. Finally, a narrow space detection task is simulated and experimented respectively. The results verify the proposed method.
文摘Continuum manipulators(CM)are soft and flexible manipulators with large numbers of degrees of freedom and can perform complex tasks in an unstructured environment.However,their deformability and compliance can deviate distal tip under uncertain external interactions.To address this challenge,a novel tension-based control scheme has been proposed to modulate the stiffness of a tendon-driven CM,reducing the tip position errors caused by uncertain external forces.To minimize the tip position error,a virtual spring is positioned between the deviated and the desired tip positions.The proposed algorithm corrects the manipulator deviated tip position,improving tension distribution and stiffness profile,resulting in higher stiffness and better performance.The corresponding task space stiffness and condition numbers are also computed under different cases,indicating the effectiveness of the tension control scheme in modulating the manipulator's stiffness.Experimental validation conducted on an in-house developed prototype confirms the practical feasibility of the proposed approach.
基金supported by the National Natural Science Foundation of China(Grant Nos.11832009,12172095,and 11902085)the Natural Science Foundation of Guangdong Province(Grant No.2021A1515010320)We are also very grateful to the anonymous reviewers for their contributions.
