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Conceptual design,modeling and compliance characterization of a novel 2-DOF rotational pointing mechanism for fast steering mirror

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Chinese Journal of Aeronautics 2020年第12期33卷 3564-3574页

作者： Muhammad ABID Jingjun YU Yan XIE Abdus SALAM Robotics Institute School of Mechanical Engineering and AutomationBeihang UniversityBeijing 100083China School of Aeronautic Science and Engineering Beihang UniversityBeijing 100083China

In this paper,a novel 2-DOF rotational pointing mechanism(RPM)is designed inspired by the guidelines of the graphical *** mechanism integrates with a fast steering mirror(FSM)for compensating pointing errors of a laser *** design intends to achieve an angular travel of±10 mrad and steers a 25 mm mirror aperture.A planar flexure with beam flexures accompanied in parallel with an axial flexure build-up mechanism *** mechanismbased RPM ensures high precision and *** characteristics are established based on the stiffness matrix method for four different planar flexure *** layout with best in-plane rotational compliance is then assessed for performance sensitivity to mechanism dimension parameters and parasitic error,thus informing the design *** stiffness in both the inplane rotational axes and stress is determined based on finite element analysis(FEA).The wire electrical discharge machining(EDM)is employed for developing the proof of concept for the RPM and is then assembled in *** are conducted to determine the rotational stiffness and angular travel about both in-plane rotational *** among theoretical,numerical and experiments reveal excellent linearity of rotational stiffness along the rotational travel *** maximum theoretical error is less than 5.5%compared with FEA while,the experimental error has a mean of 5%and 3%for both rotational axes thus satisfying the intended design requirement.

关键词： Compliant mechanism Finite element analysis Graphical approach Rotational stiffness Sensitivity analysis

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UAV Wheat Rust Detection based on FasterNet-YOLOv8

UAV Wheat Rust Detection based on FasterNet-YOLOv8

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IEEE International Conference on robotics and Biomimetics

作者： Huaiyu Liu Yueyuan Zhang Shuguang Liu Mengyang Zhao Lining Sun Department of Automation Engineering School of Mechanical and Electrical Engineering Soochow University Suzhou China Robotics and Microsystems Center School of Mechanical and Electrical Engineering Soochow University Suzhou China

This paper introduces a UAV-based wheat rust detection system employing deep learning techniques. To address the limitations of traditional wheat rust disease detection methods, such as time and labor-intensive processes, lack of real-time monitoring, and excessive pesticide usage, In this paper, the YOLOv8 algorithm, representing the forefront of object detection methods is chosen for UAV wheat rust detection. We train the model on a prepared dataset. Subsequently, we evaluated 5 models, including YOLOv5, and YOLOv8, at two different scales (n, s) based on average precision (mAP@.5), precision, recall, and FPS. The experimental outcomes establish the superiority of the enhanced FasterNet-YOLOv8 model over YOLOv8 and YOLOv5 across all metrics, encompassing detection accuracy and processing speed. These findings affirm the viability of our suggested model within the UAV wheat rust monitoring system and underscore the efficacy of the model enhancements.

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Distributed Event-Triggered Consensus of Uncertain Multi-Agent Systems Under a Directed Graph

Distributed Event-Triggered Consensus of Uncertain Multi-Age...

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American Control Conference (ACC)

作者： Yanhua Yang Jie Mei Guangfu Ma Guangdong Key Laboratory of Intelligent Morphing Mechanisms and Adaptive Robotics School of Mechanical Engineering and Automation Harbin Institute of Technology (Shenzhen) Shenzhen Guangdong China

ISBN: (数字)9798350382655

ISBN: (纸本)9798350382662

In this paper, the distributed event-triggered consensus control of uncertain multi-agent systems (MASs) under a directed graph is investigated, where the information transmission among agents is intermittent and asynchronous. Firstly, to eliminate the influence of the nonlinear uncertainties and reduce the communication burden among the agents, we employ the model reference adaptive consensus (MRACon) technique, where a reference model with the predicted relative state information initialized by intermittently collected state information of neighbors as input is introduced for each agent to track. An adaptive consensus algorithm is designed such that the uncertain MAS under a directed graph reaches consensus asymptotically. A novel graph-based Lyapunov functional is proposed to guarantee the correctness of theoretical analysis. Moreover, a lower bound of the minimum transmission interval is obtained for each agent, and thus the Zeno behavior is strictly ruled out. Finally, the effectiveness is verified by a simulation example.

关键词： Adaptation models Uncertainty Protocols Directed graphs Information processing Switches Predictive models

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Generating Realistic VRU-AV Scenarios via Social Force-Based Gradient Optimization 27

Generating Realistic VRU-AV Scenarios via Social Force-Based...

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27th IEEE International Conference on Intelligent Transportation Systems, ITSC 2024

作者： Long, Tingting Zong, Mengru Zhang, Chi Liu, Yuehu Ma, Shuangxun Li, Li National Engineering Research Center for Visual Information and Applications Institute of Artificial Intelligence and Robotics Xi'an Jiaotong University National Key Laboratory of Human-Machine Hybrid Augmented Intelligence Shaanxi Xi'an China School of Electrical Engineering Xi' An Jiaotong University Shaanxi Xi'an China School of Future Transportation Changan University Xi'an710064 China BNRist Tsinghua University Department of Automation Beijing100084 China

ISBN: (纸本)9798331505929

Validating safe and reliable interaction with vulnerable road users (VRUs) is imperative for autonomous vehicles, especially in simulation testing procedures before on-road applications. However, existing VRU agents are either with predefined routes or with collision-oriented behaviors, which limits the fidelity and diversity of scenarios. Bridging the gap between the simulated world and reality requires realistic VRU behaviors. In this paper, we apply social force to capture natural human behavior, considering how individuals are influenced by their surroundings and adhere to real-world rules. To this end, we propose HybridSFM, an improved social force model designed for characterizing human-vehicle interacting behavior. Specifically, the steering and acceleration of the VRUs are parameterized and integrated with social norms to forecast trajectories. Based on this, we further implement a gradient optimization framework for generating VRU-AV safety-critical scenarios. Firstly, VRUs are positioned randomly around the ego-agent. Differentiable simulation updates states and unrolls trajectories while backpropagation optimizes the actions of VRUs. The modified scenario is further optimized in the subsequent time step until a collision happens. The experiments demonstrate that our approach can enhance realistic safety-critical scenarios at intersection scenarios, facilitating the testing of interaction capabilities for autonomous vehicles. © 2024 IEEE.

关键词： Autonomous vehicles

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Distributed Dual-Layer Adaptive Event-Triggered Formation Tracking for Quadrotor UAVs

Distributed Dual-Layer Adaptive Event-Triggered Formation Tr...

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American Control Conference (ACC)

作者： Tianxing Chen Hongwei Zhang Guangdong Provincial Key Laboratory of Intelligent Morphing Mechanisms and Adaptive Robotics School of Mechanical Engineering and Automation Harbin Institute of Technology Shenzhen Guangdong China

ISBN: (数字)9798350382655

ISBN: (纸本)9798350382662

Achieving resource-efficient robust tracking is critical for micro aerial robotics subject to external disturbances. In this paper, a novel distributed dual-layer adaptive event-triggered controller is proposed for cooperative formation tracking under unknown disturbances. Two different triggering sequences are designed to determine the appropriate instants for communication and control updates, thus greatly reducing the update frequency of the controller and communication consumption. Moreover, adaptive event-triggered conditions with heterogeneous parameters are well-desigeed to cope with unknown disturbances, while improving the flexibility of parameter selection and excluding Zeno behavior. By employing Lyapunov theory, new sufficient conditions for ensuring the feasibility of the proposed algorithm are rigorously derived to eliminate the conservatism. The performance of the proposed algorithm is illustrated through numerical validations of co-operative formation tracking under cluttered nonlinear disturbances, and a detailed comparison with existing algorithms is made to fully demonstrate the robustness and advantage of the proposed algorithm.

关键词： Sufficient conditions Numerical simulation Stability analysis Robustness Frequency control Robots Numerical stability

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A Look-Up Table Based Inverter Nonlinearity Compensation Method Considering Parameter Inconsistency of Upper and Lower Bridge Arms

A Look-Up Table Based Inverter Nonlinearity Compensation Met...

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IEEE International Symposium on Industrial Electronics (ISIE)

作者： Yonghe Huang Dianguo Xu Yan Xu Yong Yu Junyu Zhao Xubo Gong School of Electrical Engineering and Automation Harbin Institute of Technology Harbin China The State key Laboratory of Robotics and Systems Harbin Institute of Technology Harbin China

ISBN: (数字)9798350394085

ISBN: (纸本)9798350394092

In motor drive systems, voltage source inverter (VSI) nonlinearity will produce voltage error, cause current harmonics, and affect the control performance. Among the VSI nonlinearity factors, the parasitic capacitance is the fundamental cause of the nonlinear relationship between voltage error and phase current. If the parameter inconsistency of the upper and lower bridge arm is not considered, the voltage error is an odd function. However, in practical applications, the parameters of the upper and lower bridge arms are usually slightly different, and the voltage error will no longer be an odd function. Considering the influence of parameter inconsistency, this article proposes an accurate look-up table (LUT) based method for VSI nonlinearity compensation. By injecting positive staircase current and negative staircase current separately in self-commissioning process, an accurate voltage error LUT is obtained through numerical fitting methods. The proposed method does not require any parameter of power devices. Experimental results verify the effectiveness of the proposed method.

关键词： Industrial electronics Motor drives Accuracy Voltage source inverters Fitting Bridge circuits Table lookup

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Development of a Spherical Wheel-legged Composite Mobile Robot with Multimodal Motion Capabilities

Development of a Spherical Wheel-legged Composite Mobile Rob...

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IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)

作者： Yuyang Du Ruihua Ye Wenfu Xu School of Mechanical Engineering and Automation Harbin Institute of Technology Shenzhen China Guangdong Key Laboratory of Intelligent Morphing Mechanisms and Adaptive Robotics Shenzhen China

ISBN: (数字)9798350377705

ISBN: (纸本)9798350377712

In this paper, we present a spherical wheel-legged mobile robot, aiming to meet the demands of adaptability to complex terrains and high maneuverability. It consists of a spherical main body and five-bar linkage parallel wheel-legged mechanisms. It can switch between legged and spherical modes by extending and retracting its legs according to the demands of the actual environment, thereby enhancing the overall mobility of the robot. By designing the Linear Quadratic Regulator (LQR) controller, we achieve the impact-resistant leg balancing motion and autonomous pitch adjustment for the robot on inclined surfaces in the legged configuration. For the rolling control in the spherical configuration, a hierarchical sliding mode control method and Proportional-Integral-Derivative controller (PID) are employed to control the rolling and turning of the robot. We verify the robustness of the robot in wheel-legged configuration against disturbances and the stability of its motion in spherical configuration.

关键词： Legged locomotion Torque Dynamics Switches Turning Mathematical models Stability analysis Steady-state Robots Sliding mode control

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Utilizing the Entropy Weighting Method to Determine Objective Weights in Robot Trajectory Optimization

Utilizing the Entropy Weighting Method to Determine Objectiv...

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International Conference on Communications, Information System and Computer engineering (CISCE)

作者： Nanyan Shen Hua You Jing Li Hui Qian Shanghai Key Laboratory of Intelligent Manufacturing and Robotics School of Mechatronic Engineering and Automation Shanghai University Shanghai China General Manager's Office SHANGHAI-FANUC Robotics CO.LTD Shanghai China

ISBN: (数字)9798350353174

ISBN: (纸本)9798350353181

Optimizing trajectories of collaborative robots is crucial to ensure the efficiency and safety of human-robot interactions in many manufacturing industries. This paper introduced an entropy weighting-based method for determining objective weights in trajectory optimization. Virtual simulations were conducted obtaining datasets of robot trajectory optimization so that, the application scope of the proposed weight determination method could be expanded. The validity of this method was affirmed through comparative simulation experiments. The results demonstrated that in maneuvers in the negative z-axis direction, optimized weights significantly outperformed baseline weights in terms of energy consumption and nominal trajectory tracking, with scores of 0.97 versus 0.68, and 0.82 versus 0.54, respectively. This indicates a better performance than subjective weight setting method in enhancing the performance of collaborative robot trajectory optimization.

关键词： Manufacturing industries Trajectory tracking Service robots Human-robot interaction Collaborative robots Reinforcement learning Entropy

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A Predictive Workshop Material Distribution Model 10th

A Predictive Workshop Material Distribution Model

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10th International Workshop of Advanced Manufacturing and automation, IWAMA 2020

作者： Cai, Hongxia Wu, Liangliang Shanghai Key Laboratory of Intelligent Manufacturing and Robotics School of Mechatronic Engineering and Automation Shanghai University Shanghai China

ISBN: (纸本)9789813363175

Workshop material distribution is an important part of manufacturing. Reasonable material distribution can improve the efficiency of production in the workshop and reduce the cost of production. Aiming at the workshop material distribution, this paper proposes a predictive workshop material distribution model, the core of which consists of three parts: production line material demand forecasting, distribution plan formulation, and distribution time forecasting. The distribution model comprehensively considers the distribution cost based on ensuring punctual distribution. At the end of the paper, the ability of the distribution model to control costs was verified through the simulation of production. © 2021, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Linear programming

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Analyzing the Transient Process and the Realizability of Fractional Systems Via Intermittent Control

SSRN

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SSRN 2024年

作者： Hu, Jianbing Li, Shuguang Jin, Zhe Chao, Xiaochao Wang, Xia School of Automation and Electrical Engineering Zhejiang University of Science and Technology Hangzhou310023 China Zhejiang Provincial Industrial Institute of Robotics Hangzhou310023 China State Industrial Institute of Robotics Hangzhou310023 China

In this paper, we have studied the transient process and the realizability of fractional systems via intermittent control. For any system under intermittent control in nature, there must exist a transient process. But this phenomenon is usually neglected in many of achievements obtained from fractional derivative models. By means of convolution operation and unit step function, we have studied the transient process of a fractional system under intermittent control. The research result shows that there exists a transient process and it is relevant to the whole historic process and the memory characteristics of a fractional system. No signal can cause this process to suddenly disappear. This can do well with the real physical model under intermittent control. Some examples presented in this paper verify our theorem achievements. © 2024, The Authors. All rights reserved.

关键词： Transient analysis

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