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Fast automatic docking control for electric tractors

Fundamental Research 2024年

作者： Li, Pengpeng Bai, Yu Li, Weihua Chen, Bowen You, Bindi Zhuang, Hongchao Wang, Jianfeng Gao, Haibo Deng, Zongquan School of Astronautics Harbin Institute of Technology Harbin 150001 China School of Automotive Engineering Harbin Institute of Technology (Weihai) Weihai 264201 China Yangtze River Delta HIT robot technology research institute Wuhu 241060 China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin 150001 China Tianjin University of Technology and Education Tianjin 300222 China

In this study, we investigate the automatic docking of an electric tractor with a semi-trailer in narrow and long-distance scenarios. We propose an automatic docking method based on a multi-sensor fusion high-precision positioning algorithm and a multi-strategy docking control algorithm. To solve the heading-angle error of the involved camera due to mechanical errors, a compensation value in the form of angle deviation is introduced. To alleviate the increase in the camera detection error with longitudinal distance, a piecewise coordinate compensation function is proposed. Repositioning is performed using light detection and ranging (Lidar) to improve the pose-perception accuracy to the millimeter level. To avoid the interference of point clouds on the relocation accuracy of Lidar, a search-and-location method that combines both small and large neighborhoods is proposed. To achieve the desired docking success rate, a multi-strategy-adjustment control algorithm is used to enable comprehensive adjustment, including approximate control of the maximum angle based on lateral deviation and fine proportional-integral-differential (PID) control based on lateral deviation and longitudinal distance, security check cycle and premature warning mechanism, and risk avoidance control. Finally, the reliability and stability of the design scheme are verified by conducting multiple experiments involving actual vehicles. © 2024

关键词： Automatic docking Electric tractor Fusion positioning Piecewise proportional-integral-differential

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Low Current Ripple Model Predictive Control for Interleaved Parallel Boost with Novel Cost Function

Low Current Ripple Model Predictive Control for Interleaved ...

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China International Electrical and Energy Conference (CIEEC)

作者： Shuangshuang Wang Yong Li Chengjun Liu Jianhui Hu Meng Zhao Department of Electrical Engineering Harbin Institute of Technology (HIT) Harbin China State Key Laboratory of Hydro-Power Equipment Harbin Electric Machinery Company Limited Harbin China

ISBN: (数字)9798350359558

ISBN: (纸本)9798350359565

The interleaved parallel Boost model predictive control is generally used with current phase-shift control, where the inductor currents are phase-shifted by 360°In. This results in a large inductor current ripple. This paper presents a finite control set-model predictive current control with a novel cost function. The PI form of the inductor current error is added to the cost function, which increases the robustness of the control system. The magnitude of the inductor current and the reference current is compared before performing the prediction to reduce the amount of computation. Simulation results demonstrate that the inductor current of the proposed method has a smaller ripple compared to the conventional model prediction. It has good robustness under inductance parameter mismatch.

关键词： Simulation Heuristic algorithms Predictive models Cost function Control systems Prediction algorithms Robustness

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MLPER: Multi-Level Prompts for Adaptively Enhancing Vision-Language Emotion Recognition

MLPER: Multi-Level Prompts for Adaptively Enhancing Vision-L...

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

作者： Yu Gao Weihong Ren Xinglong Xu Yan Wang Zhiyong Wang Honghai Liu School of Mechanical Engineering and Automation State Key Lab of Robotics and Systems Harbin Institute of Technology Shenzhen China

ISBN: (数字)9798350377705

ISBN: (纸本)9798350377712

In the field of robotics, vision-based Emotion Recognition (ER) has achieved significant progress, but it still faces the challenge of poor generalization ability under unconstrained conditions (e.g., occlusions and pose variations). In this work, we propose MLPER model, which introduces Vision-Language Model for Emotion Recognition to learn discriminative representations adaptively. Specifically, different from typically leveraging a hand-crafted prompt (e.g., "a photo of a [class] person"), we first establish Multi-Level Prompts from three aspects: facial expression, human posture and situational condition using large language models, like ChatGPT. Correspondingly, we extract the visual tokens from three levels: the face, body, and context. Further, to achieve fine-grained alignment at each level, we adopt textual tokens from the positive and the hard negative to query visual tokens, predicting whether a pair of image and text is matched. Experimental results demonstrate that our MLPER model outperforms the state-of-the-art methods on several ER benchmarks, especially under the conditions of occlusions and pose variations.

关键词： Emotion recognition Adaptation models Visualization Large language models Human-robot interaction Medical services Benchmark testing Chatbots Faces Intelligent robots

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Iterative learning control of trajectory tracking of robot manipulator based the SoC platform integrated motor drive and motion control 10

Iterative learning control of trajectory tracking of robot m...

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10th International Conference on Power Electronics, Machines and Drives, PEMD 2020

作者： Sun, Yongping Yang, Ming Chen, Yangyang Ni, Qinan Xu, Dianguo State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China

ISBN: (纸本)9781839535635

With the development of SoC technology, the integration of FPGA+ARM has become the development direction of SoC. For the characteristics of integrated multi-axis motion control and motor drive, this paper selects Xilinx ZYNQ-7020 system-on-chip (SOC) with integrated dual-core ARM CPU and FPGA as the hardware platform control chip, an arm core motor drive algorithm. Another ARM core completes the interactive function and motion control, and the FPGA to complete the multi-axis hardware current loop and improve the system bandwidth. The iterative learning control (ILC) technology is widely used in robots to reduce the trajectory error of robots performing repetitive tasks. Using P-type iterative learning ILC combined with feedback control, which can compensate for nonrepeating disturbance. Finally, analysis of experimental results shows that iterative learning control combined with feedback control can significantly improve tracking accuracy. © PEMD *** right reserved.

关键词： Two term control systems

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Discovering Syntactic Interaction Clues for Human-Object Interaction Detection

Discovering Syntactic Interaction Clues for Human-Object Int...

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Conference on Computer Vision and Pattern Recognition (CVPR)

作者： Jinguo Luo Weihong Ren Weibo Jiang Xi'ai Chen Qiang Wang Zhi Han Honghai Liu Harbin Institute of Technology Shenzhen State Key Laboratory of Robotics Shenyang Institute of Automation Chinese Academy of Sciences Institutes for Robotics and Intelligent Manufacturing Chinese Academy of Sciences Shenyang University

ISBN: (数字)9798350353006

ISBN: (纸本)9798350353013

Recently, Vision-Language Model (VLM) has greatly ad-vanced the Human-Object Interaction (HOI) detection. The existing VLM-based HOI detectors typically adopt a hand-crafted template (e.g., a photo of a person [action] a/an [object]) to acquire text knowledge through the VLM text encoder. However, such approaches, only encoding the action-specific text prompts in vocabulary level, may suffer from learning ambiguity without exploring the fine-grained clues from the perspective of interaction context. In this paper, we propose a novel method to discover Syntactic Interaction Clues for HOI detection (SICHOI) by using VLM. Specifically, we first investigate what are the essen-tial elements for an interaction context, and then establish a syntactic interaction bank from three levels: spatial relationship, action-oriented posture and situational condition. Further, to align visual features with the syntactic interaction bank, we adopt a multi-view extractor to jointly aggre-gate visual features from instance, interaction, and image levels accordingly. In addition, we also introduce a dual cross-attention decoder to perform context propagation be-tween text knowledge and visual features, thereby enhancing the HOI detection. Experimental results demonstrate that our proposed method achieves state-of-the-art performance on HICO-DET and V-COCO.

关键词： Visualization Vocabulary Computer vision Aggregates Detectors Syntactics Feature extraction

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Subspace-state-Based Short-Circuit Current Observer for Interturn Short-Circuit Faults in Symmetrical Six-Phase PMSMs

Subspace-State-Based Short-Circuit Current Observer for Inte...

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China International Electrical and Energy Conference (CIEEC)

作者： Huidong Wang Jianhui Hu Yong Li Meng Zhao Department of Electrical Engineering Harbin Institute of Technology (HIT) Harbin China State Key Laboratory of Hydro-Power Equipment Harbin Electric Machinery Company Limited Harbin China

ISBN: (数字)9798350359558

ISBN: (纸本)9798350359565

Interturn short-circuit fault (ISCF) is a serious fault type in machine system. This paper proposes a novel Luenberger state observer (LSD) of short-circuit current using the xy subspace states for symmetrical six-phase permanent magnet synchronous machines (PMSMs). For six-phase control systems, the current symptoms in each subspace are affected by the ISCF. Compared to the dq subspace voltage equations, the xy subspace voltage equations are simpler. To reduce the complexity of the observer matrices, the short-circuit current observer is developed by the xy subspace states. Experimental results show the effectiveness of the proposed observer for different fault severities and operating conditions.

关键词： Permanent magnet machines Symmetric matrices Parameter estimation Short-circuit currents Observers Control systems Complexity theory

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Phase equilibria in Ni-Ti-Ta ternary system

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Transactions of Nonferrous Metals Society of China 2022年第4期32卷 1178-1187页

作者： Cui-ping WANG Peng YANG Yu-hui LIANG Shui-yuan YANG Jia-jia HAN Yong LU Xing-jun LIU Fujian Provincial Key Laboratory of Materials Genome College of MaterialsXiamen UniversityXiamen 361005China State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China Institute of Materials Genome and Big Data Harbin Institute of TechnologyShenzhen 518055China

Phase diagrams of two isothermal sections of the Ni-Ti-Ta ternary system at 1000 and 1200℃in a full composition range were determined by X-ray diffraction and electron probe *** experimental results indicated a ternary compoundτphase with low solid solubility and composition ranges of(16.3-22.4)at.%Ta,(15.9-24.1)at.%Ti and(58.5-60.0)at.%Ni at 1000℃.The two terminal solid solutions(bcc-(Ta)andβ-Ti)formed a continuous solid solution at 1000 and 1200℃.A certain amount of Ti can dissolve into Ni-Ta intermetallic compounds near the Ni-Ta side,with the highest value of 21.9 at.%observed in the Ni;Ta compound at 1000℃.

关键词： microstructure Ni-Ti-Ta ternary system isothermal section phase diagram electron probe microanalysis

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Moobot: a miniature origami omnidirectional jumping robot with high trajectory accuracy

TechRxiv

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TechRxiv 2022年

作者： Tang, Lingqi Li, Yao Li, Bing School of Mechanical Engineering and Automation Harbin Institute of Technology Shenzhen Shenzhen518055 China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China

The jumping trajectory control is important for the jumping robots to overcome different obstacles. However, the trajectory control of a micro jumping robot is not easy. No insect-scale jumping robots have demonstrated the precise trajectory following yet. We proposed a miniature origami omnidirectional jumping robot (Moobot) that achieved the feedback control of jumping trajectory. The jumping of the robot is based on a four-bar origami structure and the SMA actuators. Unlike the tethered micro robots that powered externally, we integrated a miniature control board with LiPo battery on the robot for remote control. The overall system measured 6 g in mass, 5.5 cm in length and 2cm in height. Two strain gauges and an IMU sensor were used on the robot for the feedback control of the jumping force and take-off angle, respectively. Meanwhile, a reliable jumping mechanism and a novel supporting leg were designed to improve the jumping stability and trajectory accuracy. The standard deviation of the jumping distances was less than 1.4 cm, which is greatly improved from all previous micro jumping robots. Furthermore, we integrated the yaw control and conducted the omnidirectional jumping experiments. The results revealed that Moobot could climb different platforms from all directions precisely. © 2022, CC BY.

关键词： Feedback control

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Comparative study of voltage source inverter nonlinearity compensation using different signal information for table look up in PMSM drives 10

Comparative study of voltage source inverter nonlinearity co...

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10th International Conference on Power Electronics, Machines and Drives, PEMD 2020

作者： Long, Jiang Yang, Ming Chen, Yangyang Ni, Qinan Xu, Dianguo State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China

ISBN: (纸本)9781839535635

The inverter nonlinearity compensation has been studied by the researchers widely, however, due to the poor polarity detection ability of the discrete control system and unavoidable noises from current feedback, unideal compensation happens when the motor speed is low and the load is small. In order to tackle with this problem. This paper presents an inverter nonlinearity compensation method in permanent magnet synchronous motor (PMSM) drives. The overall process is achieved by voltage signal injection, the only requirements are stator resistance and the maximum current of a given motor. The corresponding voltage errors are saved in look up table (LUT) and being used together with field-oriented control (FOC). In addition, a comparative study when using phase current feedback, phase current reference and phase voltage reference for compensation voltages look-up in the already established LUT is conducted. A 750-W voltage-source inverter PMSM drive controlled by the FOC algorithm is used for experiment verification, the results show that the phase current reference is the most proper signal for compensation voltages look-up, especially around the current zero-crossing condition. The comparative study in this paper can be easily applied in the real industrial application with no hardware introduction and very little algorithm change. © PEMD *** right reserved.

关键词： Table lookup

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Dynamic Visual SLAM Based on Semantic Information and Multi-View Geometry 5

Dynamic Visual SLAM Based on Semantic Information and Multi-...

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5th International Conference on Automation, Control and robotics Engineering, CACRE 2020

作者： Shi, Junyi Zha, Fusheng Guo, Wei Wang, Pengfei Li, Mantian Harbin Institute of Technology State Key Laboratory of Robotics and System Harbin China

ISBN: (纸本)9781728198880

Visual Simultaneous Localization and Mapping (Visual SLAM) is considered to be one of the important foundations for mobile robots to move toward intelligence, which gives robots the ability to autonomously locate and construct maps in an unknown environment. In the past decades, great progress has been made in the field of visual SLAM, relatively mature algorithm system and program architecture are gradually developed. However, the current researches on visual SLAM mostly assume that the surrounding environment is static, which greatly limits the application of SLAM systems in real world. Aiming at the urgent need of mobile robots for precise localization and map construction in dynamic environment, methods are proposed in this paper. Image semantic segmentation based on deep learning and multi-view geometry methods are combined to recognize and segment moving objects. Only background features are used for camera tracking to avoid the impact of moving objects. Furthermore, an experimental platform is built using RGB-D camera and motion capture device, the effectiveness of the algorithm is verified by public datasets and real scene data. © 2020 IEEE.

关键词： Semantics

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