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By moving a commercial 2D LiDAR, 3D maps of the environment can be built, based on the data of a 2D LiDAR and its movements. Compared to a commercial 3D LiDAR, a moving 2D LiDAR is more economical. A series of problems need to be solved in order for a moving 2D LiDAR to perform better, among them, improving accuracy and real-time performance. In order to solve these problems, estimating the movements of a 2D LiDAR, and identifying and removing moving objects in the environment, are issues that should be studied. More specifically, calibrating the installation error between the 2D LiDAR and the moving unit, the movement estimation of the moving unit, and identifying moving objects at low scanning frequencies, are involved. As actual applications are mostly dynamic, and in these applications, a moving 2D LiDAR moves between multiple moving objects, we believe that, for a moving 2D LiDAR, how to accurately construct 3D maps in dynamic environments will be an important future research topic. Moreover, how to deal with moving objects in a dynamic environment via a moving 2D LiDAR has not been solved by previous research.
Shusheng Bi; Chang Yuan; Chang Liu; Jun Cheng; Wei Wang; Yueri Cai. A Survey of Low-Cost 3D Laser Scanning Technology. Applied Sciences 2021, 11, 3938 .
AMA StyleShusheng Bi, Chang Yuan, Chang Liu, Jun Cheng, Wei Wang, Yueri Cai. A Survey of Low-Cost 3D Laser Scanning Technology. Applied Sciences. 2021; 11 (9):3938.
Chicago/Turabian StyleShusheng Bi; Chang Yuan; Chang Liu; Jun Cheng; Wei Wang; Yueri Cai. 2021. "A Survey of Low-Cost 3D Laser Scanning Technology." Applied Sciences 11, no. 9: 3938.
For a rotating 2D lidar, the inaccurate matching between the 2D lidar and the motor is an important error resource of the 3D point cloud, where the error is shown both in shape and attitude. Existing methods need to measure the angle position of the motor shaft in real time to synchronize the 2D lidar data and the motor shaft angle. However, the sensor used for measurement is usually expensive, which can increase the cost. Therefore, we propose a low-cost method to calibrate the matching error between the 2D lidar and the motor, without using an angular sensor. First, the sequence between the motor and the 2D lidar is optimized to eliminate the shape error of the 3D point cloud. Next, we eliminate the attitude error with uncertainty of the 3D point cloud by installing a triangular plate on the prototype. Finally, the Levenberg–Marquardt method is used to calibrate the installation error of the triangular plate. Experiments verified that the accuracy of our method can meet the requirements of the 3D mapping of indoor autonomous mobile robots. While we use a 2D lidar Hokuyo UST-10LX with an accuracy of ±40 mm in our prototype, we can limit the mapping error within ±50 mm when the distance is no more than 2.2996 m for a 1 s scan (mode 1), and we can limit the mapping error within ±50 mm at the measuring range 10 m for a 16 s scan (mode 7). Our method can reduce the cost while the accuracy is ensured, which can make a rotating 2D lidar cheaper.
Chang Yuan; Shusheng Bi; Jun Cheng; Dongsheng Yang; Wei Wang. Low-Cost Calibration of Matching Error between Lidar and Motor for a Rotating 2D Lidar. Applied Sciences 2021, 11, 913 .
AMA StyleChang Yuan, Shusheng Bi, Jun Cheng, Dongsheng Yang, Wei Wang. Low-Cost Calibration of Matching Error between Lidar and Motor for a Rotating 2D Lidar. Applied Sciences. 2021; 11 (3):913.
Chicago/Turabian StyleChang Yuan; Shusheng Bi; Jun Cheng; Dongsheng Yang; Wei Wang. 2021. "Low-Cost Calibration of Matching Error between Lidar and Motor for a Rotating 2D Lidar." Applied Sciences 11, no. 3: 913.
Compared with the lever-type amplifier, the rhombus-type amplifier has attracted more attention by virtue of large displacement amplification ratio, compact structure, and linear output displacement. In this paper, a novel electromagnetic force balance sensor (EFBS) based on the rhombus-type amplifier is presented to measure the mass with high precision. First, the structure and operating principle of the EFBS are described, and the requirements for the design and manufacture of the amplifier are put forward. Then, the analytical models of the two-stage rhombus-type amplifier are given out, and two guiding mechanisms are analyzed and modeled. Furthermore, the validity of the established model is verified by finite element analysis (FEA). Thanks to the theoretical guidance, an electromagnetic force balance sensor based on the two-stage rhombus-type amplifier and double parallelogram flexure mechanism is designed and tested. The experimental results demonstrate that the developed EFBS can measure the mass of the objects with high precision, and also verifies the correctness of the analytical model. This provides a new concept for the structural design of the EFBS.
Yongzhen Li; Xiaofeng Zhu; Shusheng Bi; Ruihua Guo; Jianhai Sun; Wencheng Hu. Design and development of compliant mechanisms for electromagnetic force balance sensor. Precision Engineering 2020, 64, 157 -164.
AMA StyleYongzhen Li, Xiaofeng Zhu, Shusheng Bi, Ruihua Guo, Jianhai Sun, Wencheng Hu. Design and development of compliant mechanisms for electromagnetic force balance sensor. Precision Engineering. 2020; 64 ():157-164.
Chicago/Turabian StyleYongzhen Li; Xiaofeng Zhu; Shusheng Bi; Ruihua Guo; Jianhai Sun; Wencheng Hu. 2020. "Design and development of compliant mechanisms for electromagnetic force balance sensor." Precision Engineering 64, no. : 157-164.
In order to accurately reveal the kinematic characteristics, the nonlinearities of load-equilibrium equations associated with the deflection of the flexible elements cannot be neglected, especially for the distributed-compliance compliant mechanisms. The object of this paper is to present a nonlinear analytical model of rhombus-type amplifier based on the beam flexures and to evaluate the effect of forces so as to offer helpful for initial parametric design studies. Based on the beam constraint model (BCM), the nonlinear analytical models of the one-stage and two-stage rhombus-type amplifiers are established respectively with some permissible approximations. Then, the input stiffness and off-axis stiffness models are formulated respectively, and the stiffness characteristic analysis is also carried out. Additionally, finite element analysis (FEA) is conducted to evaluate responses of the model with various parameters under the action of different forces. Finally, experimental studies of the performances are carried out, and the experimental results are compared with the theoretical models and FEA results. The nonlinear behaviors in the displacement, amplification ratio and input stiffness are revealed accurately, and the reason why the amplification ratio of the two-stage amplifier is different from the expected value is explained.
Yongzhen Li; Shusheng Bi; Chenxi Zhao. Analytical modeling and analysis of rhombus-type amplifier based on beam flexures. Mechanism and Machine Theory 2019, 139, 195 -211.
AMA StyleYongzhen Li, Shusheng Bi, Chenxi Zhao. Analytical modeling and analysis of rhombus-type amplifier based on beam flexures. Mechanism and Machine Theory. 2019; 139 ():195-211.
Chicago/Turabian StyleYongzhen Li; Shusheng Bi; Chenxi Zhao. 2019. "Analytical modeling and analysis of rhombus-type amplifier based on beam flexures." Mechanism and Machine Theory 139, no. : 195-211.
The state-of-the-art visual simultaneous localization and mapping (V-SLAM) systems have high accuracy localization capabilities and impressive mapping effects. However, most of these systems assume that the operating environment is static, thereby limiting their application in the real dynamic world. In this paper, by fusing the information of an RGB-D camera and two encoders that are mounted on a differential-drive robot, we aim to estimate the motion of the robot and construct a static background OctoMap in both dynamic and static environments. A tightly coupled feature-based method is proposed to fuse the two types of information based on the optimization. Dynamic pixels occupied by dynamic objects are detected and culled to cope with dynamic environments. The ability to identify the dynamic pixels on both predefined and undefined dynamic objects is available, which is attributed to the combination of the CPU-based object detection method and a multiview constraint-based approach. We first construct local sub-OctoMaps by using the keyframes and then fuse the sub-OctoMaps into a full OctoMap. This submap-based approach gives the OctoMap the ability to deform, and significantly reduces the map updating time and memory costs. We evaluated the proposed system in various dynamic and static scenes. The results show that our system possesses competitive pose accuracy and high robustness, as well as the ability to construct a clean static OctoMap in dynamic scenes.
Dongsheng Yang; Shusheng Bi; Wei Wang; Chang Yuan; Xianyu Qi; Yueri Cai. DRE-SLAM: Dynamic RGB-D Encoder SLAM for a Differential-Drive Robot. Remote Sensing 2019, 11, 380 .
AMA StyleDongsheng Yang, Shusheng Bi, Wei Wang, Chang Yuan, Xianyu Qi, Yueri Cai. DRE-SLAM: Dynamic RGB-D Encoder SLAM for a Differential-Drive Robot. Remote Sensing. 2019; 11 (4):380.
Chicago/Turabian StyleDongsheng Yang; Shusheng Bi; Wei Wang; Chang Yuan; Xianyu Qi; Yueri Cai. 2019. "DRE-SLAM: Dynamic RGB-D Encoder SLAM for a Differential-Drive Robot." Remote Sensing 11, no. 4: 380.
This paper simultaneously calibrates odometry parameters and the relative pose between a monocular camera and a robot automatically. Most camera pose estimation methods use natural features or artificial landmark tools. However, there are mismatches and scale ambiguity for natural features; the large-scale precision landmark tool is also challenging to make. To solve these problems, we propose an automatic process to combine multiple composite targets, select keyframes, and estimate keyframe poses. The composite target consists of an aruco marker and a checkerboard pattern. First, an analytical method is applied to obtain initial values of all calibration parameters; prior knowledge of the calibration parameters is not required. Then, two optimization steps are used to refine the calibration parameters. Planar motion constraints of the camera are introduced in these optimizations. The proposed solution is automatic; manual selection of keyframes, initial values, and robot construction within a specific trajectory are not required. The competing accuracy and stability of the proposed method under different target placements and robot paths are tested experimentally. Positive effects on calibration accuracy and stability are obtained when (1) composite targets are adopted; (2) two optimization steps are used; (3) plane motion constraints are introduced; and (4) target numbers are increased.
Shusheng Bi; Dongsheng Yang; Yueri Cai. Automatic Calibration of Odometry and Robot Extrinsic Parameters Using Multi-Composite-Targets for a Differential-Drive Robot with a Camera. Sensors 2018, 18, 3097 .
AMA StyleShusheng Bi, Dongsheng Yang, Yueri Cai. Automatic Calibration of Odometry and Robot Extrinsic Parameters Using Multi-Composite-Targets for a Differential-Drive Robot with a Camera. Sensors. 2018; 18 (9):3097.
Chicago/Turabian StyleShusheng Bi; Dongsheng Yang; Yueri Cai. 2018. "Automatic Calibration of Odometry and Robot Extrinsic Parameters Using Multi-Composite-Targets for a Differential-Drive Robot with a Camera." Sensors 18, no. 9: 3097.
The aim of this paper is to estimate the ego-motion of an RGB-D camera in dynamic environments. A semi-direct motion estimation pipeline is modified for the RGB-D camera. In order to avoid the impact of dynamic objects, a new mapping method based on scoring mechanism is proposed, which can effectively remove feature points on dynamic objects and results a map contains only static points. The method is evaluated not only with the TUM RGB-D benchmark but also using an Asus Xtion Pro Live camera in a dynamic office environment. The experimental results show that our method has higher accuracy in dynamic environments and has considerable accuracy in static environments. In some high dynamic scenes, the accuracy of our method is more than 7 times higher than other RGB-D visual odometry algorithms.
Dongsheng Yang; Shusheng Bi; Yueri Cai; Jingxiang Zheng; Chang Yuan. Dynamic RGB-D visual odometry. 2017 IEEE International Conference on Robotics and Biomimetics (ROBIO) 2017, 1 .
AMA StyleDongsheng Yang, Shusheng Bi, Yueri Cai, Jingxiang Zheng, Chang Yuan. Dynamic RGB-D visual odometry. 2017 IEEE International Conference on Robotics and Biomimetics (ROBIO). 2017; ():1.
Chicago/Turabian StyleDongsheng Yang; Shusheng Bi; Yueri Cai; Jingxiang Zheng; Chang Yuan. 2017. "Dynamic RGB-D visual odometry." 2017 IEEE International Conference on Robotics and Biomimetics (ROBIO) , no. : 1.
Variable stiffness actuator (VSA) can significantly improve the dynamic performance of robots and ensure safety in human robot interaction. In this paper, a novel structure-controlled VSA which achieves a lower minimal stiffness while the size and load capacity remain unchanged is introduced. Stiffness variation is implemented by changing the effective length of parallel-assembled-folded serial leaf springs presented in this paper, which makes the adjustment of stiffness easier and driven by an independent motor. A modified analytical model of joint stiffness is built, which takes the gap between leaf springs and rollers into consideration. Experiments prove that the modified model is more accurate comparing with the ideal model which ignores the gap. Further analyses show that the gap can even make serious impacts on leaf spring-based structure-controlled VSA in other performances such as deformability and energy capacity.
S. S. Bi; C. Liu; H. Z. Zhao; Y. L. Wang. Design and analysis of a novel variable stiffness actuator based on parallel-assembled-folded serial leaf springs. Advanced Robotics 2017, 31, 990 -1001.
AMA StyleS. S. Bi, C. Liu, H. Z. Zhao, Y. L. Wang. Design and analysis of a novel variable stiffness actuator based on parallel-assembled-folded serial leaf springs. Advanced Robotics. 2017; 31 (18):990-1001.
Chicago/Turabian StyleS. S. Bi; C. Liu; H. Z. Zhao; Y. L. Wang. 2017. "Design and analysis of a novel variable stiffness actuator based on parallel-assembled-folded serial leaf springs." Advanced Robotics 31, no. 18: 990-1001.
Pectoral fin motion discipline of the cownose ray as a nature prototype is analyzed. According to the analysis results, a bionic pectoral fin with multiple fin rays and one revolute wingtip is designed. The angle of attack distribution principle of the bionic pectoral fin is also analyzed. The analysis results show that the angle of attack of pectoral fin reaches its maximum at the wingtip. In order to improve the deformation ability of the tip of rigid fin ray, a novel revolute joint is designed and applied to the bionic pectoral fin. The simulation results show that the maximum angle of attack of the revolute wingtip can reach about 35°.The relationship between the pitching angle of fin tip and the average thrust/lift generated by pectoral fins is analyzed. In the thrust/lift experiments, with the help of the revolute joint, the maximal average thrust of 3.3N is achieved and the maximal absolute value of average lift is less than 2N. In the swimming experiments, a maximum forward speed of 0.7BL/s (body length/s) is reached. Under the same motion parameters, the maximum speed decreases to 0.35BL/s when the revolute joint is locked.
Zhao Gong; Yueri Cai; Hongwei Ma; Yong Cao; Shusheng Bi. DESIGN AND IMPLEMENTATION OF A ROBOTIC FISH BASED ON REVOLUTE WINGTIPS. Assistive Robotics 2015, 1 .
AMA StyleZhao Gong, Yueri Cai, Hongwei Ma, Yong Cao, Shusheng Bi. DESIGN AND IMPLEMENTATION OF A ROBOTIC FISH BASED ON REVOLUTE WINGTIPS. Assistive Robotics. 2015; ():1.
Chicago/Turabian StyleZhao Gong; Yueri Cai; Hongwei Ma; Yong Cao; Shusheng Bi. 2015. "DESIGN AND IMPLEMENTATION OF A ROBOTIC FISH BASED ON REVOLUTE WINGTIPS." Assistive Robotics , no. : 1.
Purpose – This paper aims to develop a robofish with oscillating pectoral fins, and control it to mimic the bionic prototype by central pattern generators (CPGs). Design/methodology/approach – First, the oscillation characteristics of the cownose ray were analyzed quantitatively. Second, a robofish with multi-joint pectoral fins was developed according to the bionic morphology and kinematics. Third, the improved phase oscillator was established, which contains a spatial asymmetric coefficient and a temporal asymmetric coefficient. Moreover, the CPG network is created to mimic the cownose ray and accomplish three-dimensional (3D) motions. Finally, the experiments were done to test the authors ' works. Findings – The results demonstrate that the CPGs is effective to control the robofish to imitate the cownose ray realistically. In addition, the robofish is able to accomplish 3D motions of high maneuverability, and change among different swimming modes quickly and smoothly. Originality/value – The research provides the method to develop a robofish from both 3D morphology and kinematics. The motion analysis and CPG control make sure that the robofish has the features of high maneuverability and camouflage. It is useful for military underwater applications and underwater detections in narrow environments. Second, this work lays the foundation for the autonomous 3D control. Moreover, the robotic fish can be taken as a scientific tool for the fluid bionics research.
Yong Cao; Shusheng Bi; Yueri Cai; Yuliang Wang. Applying central pattern generators to control the robofish with oscillating pectoral fins. Industrial Robot: the international journal of robotics research and application 2015, 42, 392 -405.
AMA StyleYong Cao, Shusheng Bi, Yueri Cai, Yuliang Wang. Applying central pattern generators to control the robofish with oscillating pectoral fins. Industrial Robot: the international journal of robotics research and application. 2015; 42 (5):392-405.
Chicago/Turabian StyleYong Cao; Shusheng Bi; Yueri Cai; Yuliang Wang. 2015. "Applying central pattern generators to control the robofish with oscillating pectoral fins." Industrial Robot: the international journal of robotics research and application 42, no. 5: 392-405.
Purpose The paper aims to develop a cownose ray-inspired robotic fish which can be propelled by oscillating and chordwise twisting pectoral fins. Design/methodology/approach The bionic pectoral fin which can simultaneously realize the combination of oscillating motion and chordwise twisting motion is designed based on analyzing the movement of cownose ray’s pectoral fins. The structural design and control system construction of the robotic fish are presented. Finally, a series of swimming experiments are carried out to verify the effectiveness of the design for the bionic pectoral fin. Findings The experimental results show that the deformation of the bionic pectoral fin can be well close to that of the cownose ray’s. The bionic pectoral fin can produce effective angle of attack, and the thrust generated can propel robotic fish effectively. Furthermore, the tests of swimming performance in the water tank show that the robotic fish can achieve a maximum forward speed of 0.43 m/s (0.94 times of body length per second) and an excellent turning maneuverability with a small radius. Originality/value The oscillating and pitching motion can be obtained simultaneously by the active control of chordwise twisting motion of the bionic pectoral fin, which can better imitate the movement of cownose ray’s pectoral fin. The designed bionic pectoral fin can provide an experimental platform for further study of the effect of the spanwise and chordwise flexibility on propulsion performance.
Hongwei Ma; Yueri Cai; Yuliang Wang; Shusheng Bi; Zhao Gong. A biomimetic cownose ray robot fish with oscillating and chordwise twisting flexible pectoral fins. Industrial Robot: the international journal of robotics research and application 2015, 42, 214 -221.
AMA StyleHongwei Ma, Yueri Cai, Yuliang Wang, Shusheng Bi, Zhao Gong. A biomimetic cownose ray robot fish with oscillating and chordwise twisting flexible pectoral fins. Industrial Robot: the international journal of robotics research and application. 2015; 42 (3):214-221.
Chicago/Turabian StyleHongwei Ma; Yueri Cai; Yuliang Wang; Shusheng Bi; Zhao Gong. 2015. "A biomimetic cownose ray robot fish with oscillating and chordwise twisting flexible pectoral fins." Industrial Robot: the international journal of robotics research and application 42, no. 3: 214-221.
Swimming mode utilizing oscillating pectoral fins possess characteristics of high efficiency, high stability, high maneuverability, and higher swimming velocity compared with other swimming modes of fish. Broad application prospect and important research value are shown by robotic fish propelled by oscillating pectoral fins. The research on bionic fish of this kind has become a hot pot. In this chapter, structure characteristics and pectoral fin motion deformation during oscillation of the nature sample, cownose ray, are analyzed. Main structure parameters of the sample cownose ray and simple mathematical model of oscillating movement of the pectoral fin are obtained. Finally, a robotic fish propelled by oscillating pectoral foils featuring with organic combination of form bionic and function bionic is developed.
Yueri Cai; Shusheng Bi; Hongwei Ma. Research on Robotic Fish Propelled by Oscillating Pectoral Fins. Materials with Internal Structure 2015, 119 -160.
AMA StyleYueri Cai, Shusheng Bi, Hongwei Ma. Research on Robotic Fish Propelled by Oscillating Pectoral Fins. Materials with Internal Structure. 2015; ():119-160.
Chicago/Turabian StyleYueri Cai; Shusheng Bi; Hongwei Ma. 2015. "Research on Robotic Fish Propelled by Oscillating Pectoral Fins." Materials with Internal Structure , no. : 119-160.
Purpose – The paper aims to present a dynamic model of flexible oscillating pectoral fin for further study on its propulsion mechanism. Design/methodology/approach – The chordwise and spanwise motions of cow-nosed ray’s pectoral fin are first analyzed based on the mechanism of active/passive flexible deformation. The kinematic model of oscillating pectoral fin is established by introducing the flexible deformation. Then, the dynamic model of the oscillating pectoral fin is developed based on the quasi-steady blade element theory. A series of hydrodynamic experiments on the oscillating pectoral fin are carried out to investigate the influences of motion parameters on the propulsion performance of the oscillating pectoral fin. Findings – The experimental results are consistent with that obtained through analytical calculation within a certain range, which indicates that the developed dynamic model in this paper is applicable to describe the dynamic characteristics of the oscillating pectoral fin approximately. The experimental results show that the average thrust of an oscillating pectoral fin increases with the increasing oscillating amplitude and frequency. However, the relationship between the average thrust and the oscillating frequency is nonlinear. Moreover, the experimental results show that there is an optimal phase difference at which the oscillating pectoral fin achieves the maximum average thrust. Originality/value – The developed dynamic model provides the theoretical basis for further research on propulsion mechanism of oscillating pectoral fins. It can also be used in the design of the bionic pectoral fins.
Shusheng Bi; Hongwei Ma; Yueri Cai; Chuanmeng Niu; Yuliang Wang. Dynamic modeling of a flexible oscillating pectoral fin for robotic fish. Industrial Robot: the international journal of robotics research and application 2014, 41, 421 -428.
AMA StyleShusheng Bi, Hongwei Ma, Yueri Cai, Chuanmeng Niu, Yuliang Wang. Dynamic modeling of a flexible oscillating pectoral fin for robotic fish. Industrial Robot: the international journal of robotics research and application. 2014; 41 (5):421-428.
Chicago/Turabian StyleShusheng Bi; Hongwei Ma; Yueri Cai; Chuanmeng Niu; Yuliang Wang. 2014. "Dynamic modeling of a flexible oscillating pectoral fin for robotic fish." Industrial Robot: the international journal of robotics research and application 41, no. 5: 421-428.
Shusheng Bi; Chuanmeng Niu; Yueri Cai; Lige Zhang; Houxiang Zhang. A waypoint-tracking controller for a bionic autonomous underwater vehicle with two pectoral fins. Advanced Robotics 2014, 28, 673 -681.
AMA StyleShusheng Bi, Chuanmeng Niu, Yueri Cai, Lige Zhang, Houxiang Zhang. A waypoint-tracking controller for a bionic autonomous underwater vehicle with two pectoral fins. Advanced Robotics. 2014; 28 (10):673-681.
Chicago/Turabian StyleShusheng Bi; Chuanmeng Niu; Yueri Cai; Lige Zhang; Houxiang Zhang. 2014. "A waypoint-tracking controller for a bionic autonomous underwater vehicle with two pectoral fins." Advanced Robotics 28, no. 10: 673-681.
Straight-line compliant mechanisms are important building blocks to design a linear-motion stage, which is very useful in precision applications. However, only a few configurations of straight-line compliant mechanisms are applicable. To construct more kinds of them, an approach to design large-displacement straight-line flexural mechanisms with rotational flexural joints is proposed, which is based on a viewpoint that the straight-line motion is regarded as a compromise of rigid and compliant parasitic motion of a rotational flexural joint. An analytical design method based on the Taylor series expansion is proposed to quickly obtain an approximate solution. To illustrate and verify the proposed method, two kinds of flexural joints, cross-axis hinge and leaf-type isosceles-trapezoidal flexural(LITF) pivot are used to reconstruct straight-line flexural mechanisms. Their performances are obtained by analytic and FEA method respectively. The comparisons of the results show the accuracy of the approach. Both examples show that the proposed approach can convert a large-deflection flexural joint into approximate straight-line mechanism with a high linearity that is higher than 5 000 within 5 mm displacement. This can lead to a new way to design, analyze or optimize straight-line flexure mechanisms.
Xu Pei; Jingjun Yu; Guanghua Zong; Shusheng Bi. Design of compliant straight-line mechanisms using flexural joints. Chinese Journal of Mechanical Engineering 2014, 27, 146 -153.
AMA StyleXu Pei, Jingjun Yu, Guanghua Zong, Shusheng Bi. Design of compliant straight-line mechanisms using flexural joints. Chinese Journal of Mechanical Engineering. 2014; 27 (1):146-153.
Chicago/Turabian StyleXu Pei; Jingjun Yu; Guanghua Zong; Shusheng Bi. 2014. "Design of compliant straight-line mechanisms using flexural joints." Chinese Journal of Mechanical Engineering 27, no. 1: 146-153.
Cross-spring pivots, formed by crossing two identical flexural beams at their midpoint, have been broadly used in precision engineering and aerospace fields. Many researches have been conducted on modeling and analysis of cross-spring pivots. However the influence of application position and magnitude of the external loads on the load-rotation and parasitic motion characteristics has not yet been discussed. In order to reveal the effect of the external loads, this paper develops the accurate load-rotation and center shift models of cross-spring pivots, with generalized planar loads applied including bending moment, horizontal and vertical forces. Firstly, by using the energy method, the load-displacement models of the pivot are derived with the assumption of small rotational angles. Based on the models, the influence of generalized planar loads on the load-rotation relationship is discussed, which shows that both application position and magnitude of the vertical and horizontal forces influence the load-rotation behaviors. Then the accurate center shift expressions of the pivot with generalized planar loads are developed, which shows that the rotational angle is the dominant term for both components of the center shift while the vertical and horizontal forces are small. Finally, the accuracy of the proposed model is validated by finite element analysis(FEA). Comparing the model data with the results obtained from FEA, the relative error of the load-rotation is less than 6% even if the rotational angle reaches 20°; the relative errors of the two components of center shift are less than 5% and 10% respectively when the rotational angle reaches 10°. The proposed model and analytical conclusions can be used to analyze and preliminarily design the compliant mechanisms containing cross-spring pivots.
Shusheng Bi; Yanbin Yao; Shanshan Zhao; Jingjun Yu. Modeling of cross-spring pivots subjected to generalized planar loads. Chinese Journal of Mechanical Engineering 2012, 25, 1075 -1085.
AMA StyleShusheng Bi, Yanbin Yao, Shanshan Zhao, Jingjun Yu. Modeling of cross-spring pivots subjected to generalized planar loads. Chinese Journal of Mechanical Engineering. 2012; 25 (6):1075-1085.
Chicago/Turabian StyleShusheng Bi; Yanbin Yao; Shanshan Zhao; Jingjun Yu. 2012. "Modeling of cross-spring pivots subjected to generalized planar loads." Chinese Journal of Mechanical Engineering 25, no. 6: 1075-1085.
Spanwise flexibility is a key factor influencing propulsion performance of pectoral foils.Performances of bionic fish with oscillating pectoral foils can be enhanced by properly selecting the spanwise flexibility.The influence law of spanwise flexibility on thrust generation and propulsion efficiency of a rectangular hydro-foil is discussed.Series foils constructed by the two-component silicon rubber are developed.NACA0015 shape of chordwise cross-section is employed.The foils are strengthened by fin rays of different rigidity to realize variant spanwise rigidity and almost the same chordwise flexibility.Experiments on a towing platform developed are carried out at low Reynolds numbers of 10 000,15 000,and 20 000 and Strouhal numbers from 0.1 to 1.The following experimental results are achieved: (1) The average forward thrust increases with the St number increased;(2) Certain degree of spanwise flexibility is beneficial to the forward thrust generation,but the thrust gap is not large for the fins of different spanwise rigidity;(3) The fin of the maximal spanwise flexibility owns the highest propulsion efficiency;(4) Effect of the Reynolds number on the propulsion efficiency is significant.The experimental results can be utilized as a reference in deciding the spanwise flexibility of bionic pectoral fins in designing of robotic fish prototype propelled by flapping-wing.
Shusheng Bi; Yueri Cai. Effect of spanwise flexibility on propulsion performance of a flapping hydrofoil at low Reynolds number. Chinese Journal of Mechanical Engineering 2012, 25, 12 -19.
AMA StyleShusheng Bi, Yueri Cai. Effect of spanwise flexibility on propulsion performance of a flapping hydrofoil at low Reynolds number. Chinese Journal of Mechanical Engineering. 2012; 25 (1):12-19.
Chicago/Turabian StyleShusheng Bi; Yueri Cai. 2012. "Effect of spanwise flexibility on propulsion performance of a flapping hydrofoil at low Reynolds number." Chinese Journal of Mechanical Engineering 25, no. 1: 12-19.
This paper aims to design a novel bionic fish propelled by oscillating paired pectoral fins. Flapping motion deformation of the nature sample, the cow-nosed ray, is realized with simple mechanical structure through optimization. Locomotion analysis of the nature sample under linear cruise swimming conditions is carried out. Simplified mathematical models of the pectoral fin are obtained to be the design foundation of the bionic fin rays and the bionic fish. The number of fin rays is decided according to the passing kinematic wave shape and number. Distance and structure parameters are optimized, and determined by the minimum area error method. A novel two-stage slide–rocker mechanism is designed to fulfill the driving requirements with only one servo motor. System design of a new bionic fish robot is presented, including the mechanical design and the control method. Main bionic characteristics extracted from the cow-nosed ray are fulfilled by the prototype and verified by experiments.
Yueri Cai; Shusheng Bi; Licheng Zheng. Design Optimization of a Bionic Fish with Multi-Joint Fin Rays. Advanced Robotics 2012, 26, 177 -196.
AMA StyleYueri Cai, Shusheng Bi, Licheng Zheng. Design Optimization of a Bionic Fish with Multi-Joint Fin Rays. Advanced Robotics. 2012; 26 (1-2):177-196.
Chicago/Turabian StyleYueri Cai; Shusheng Bi; Licheng Zheng. 2012. "Design Optimization of a Bionic Fish with Multi-Joint Fin Rays." Advanced Robotics 26, no. 1-2: 177-196.
The cow-nosed ray is studied as natural sample of a flapping-foil robotic fish. Body structure, motion discipline, and dynamic foil deformation of cow-nosed ray are analyzed. Based on the analysis results, a robotic fish imitating cow-nosed ray, named Robo-ray II, mainly composed of soft body, flexible ribs and pneumatic artificial muscles, is developed. Structure and swimming morphology of the robotic prototype are as that of a normal cow-nosed ray in nature. Key propulsion parameters of Robo-ray II at normal conditions, including the St Number at linear swimming, thrust coefficient at towing are studied through experiments. The suitable driving parameters are confirmed considering the efficiency and swimming velocity. Swimming velocity of 0.16 m·s−1 and thrust coefficient of 0.56 in maximum are achieved in experiments.
Yueri Cai; Shusheng Bi; Licheng Zheng. Design and Experiments of a Robotic Fish Imitating Cow-Nosed Ray. Journal of Bionic Engineering 2010, 7, 120 -126.
AMA StyleYueri Cai, Shusheng Bi, Licheng Zheng. Design and Experiments of a Robotic Fish Imitating Cow-Nosed Ray. Journal of Bionic Engineering. 2010; 7 (2):120-126.
Chicago/Turabian StyleYueri Cai; Shusheng Bi; Licheng Zheng. 2010. "Design and Experiments of a Robotic Fish Imitating Cow-Nosed Ray." Journal of Bionic Engineering 7, no. 2: 120-126.
This paper presents the development of a drill end effector for use on industrial robots. The end effector has low weight and high rigidity. The drill end effector is fully programmable and will realize different drilling mode. The real-time force feedback can detect dull or broken bits, drill to breakthrough, and plot thrust force while drilling. Additionally, the end effector can also be equipped with a coolant/lubricant device. Based on the drill end effector, an experimental study on dry drilling of Ti-6Al-4V alloy and 7075-T6 alloy bimetal stacks was performed by using an uncoated cemented carbide drill. The hole quality (hole size, surface roughness) and thrust force were evaluated at various spindle speeds, feed rates, stacking sequence, and clamp force. This study indicates that the spindle speed and feed rate have an effect on the hole quality and thrust force by means of changing the temperature and plastic deformation of cutting zone. The results show that drilling 7075-T6 alloy firstly would be most efficient because of the high hole quality and the low thrust force. It was also found that high clamp force is helpful to improve the hole quality.
Jie Liang; Shusheng Bi. Design and experimental study of an end effector for robotic drilling. The International Journal of Advanced Manufacturing Technology 2010, 50, 399 -407.
AMA StyleJie Liang, Shusheng Bi. Design and experimental study of an end effector for robotic drilling. The International Journal of Advanced Manufacturing Technology. 2010; 50 (1-4):399-407.
Chicago/Turabian StyleJie Liang; Shusheng Bi. 2010. "Design and experimental study of an end effector for robotic drilling." The International Journal of Advanced Manufacturing Technology 50, no. 1-4: 399-407.