In order to successfully simulate the crushing process of iron ore in a gyratory crusher, it is crucial to precisely model the iron ore based on the bonded-particle model, this requires reasonably calibrated micromechanical parameters in the model. In this study, a calibration method for iron ore BPM bonding parameters was proposed. Firstly the combination of the design of experimental method and discrete element simulation tests was used to investigate the effects of normal stiffness per unit area, shear stiffness per unit area, critical normal stress, and critical shear stress on the compressive strength and critical strain properties of the BPM. Furthermore, a fitted mathematical model between micro-mechanical parameters and macro-mechanical property parameters of iron ore was established. According to this, a bonding parameter calibration method based on Kriging surrogate model for the iron ore bonded-particle model is proposed. Finally, the micromechanical parameters of the calibrated actual iron ore bonded-particle model were verified by simulation test, which confirmed the accuracy and reliability of the proposed method and provided a new idea for the subsequent related research.

This article summarizes the research significance and the development status of the unmanned ground tracked vehicles (UGTVs). According to the speed and steering principle of the UGTVs in plane motion, the kinematic state space equation of the vehicle is established. Based on the model predictive control (MPC), the UGTVs trajectory tracking controller is also established. After introducing the overall control system solution, based on the vehicle model, the track speed on both sides is used as the control input to solve the predicted output of the system. After constraining the control amount, the model prediction controller is established by using S function. Several simulations with different preset speeds are performed under linear conditions, and the numerical simulation with different prediction time domains and control time domains are performed under continuous curves. The test validates the effectiveness of the controller, and the effects of speed and time domain parameters on the deviation are analyzed based on the results. Based on satellite positioning technology, trajectory tracking tests of the UGTVs are carried out. After analyzing the positioning principle and common errors, the real-time kinematic technology is used to improve the positioning accuracy of the vehicle prototype. The hardware of the test platform includes a data acquisition system, a control execution system and a walking execution system, and the software part includes data processing and optimization control. The trajectory tracking experiments under different driving conditions are conducted, and the results show that the navigation tracking system can achieve good tracking performance. © 2023 by the authors.

对影响立式螺旋搅拌磨机工作性能的主要结构及特征参数进行了分析研究，提出了关键工作参数选择方法。基于离散元方法，建立了立式螺旋搅拌磨机的仿真模型，分析了主轴转速、搅拌器导程和研磨介质尺寸分布对磨矿性能的影响。并提出了综合磨矿性能指标，对各参数进行正交试验，得到了磨矿效果的量化值，进而得到了在特定权重系数下的最优工作参数组合，为磨机的优化设计提供了参考方法。

六履带行走装置担负着斗轮挖掘机、排土机和移动式破碎站等大型机械的承重、移动与转向行走,其行驶特性直接影响斗轮挖掘机的工作安全性和工作效率,对多履带机械行驶理论、机电耦合动力学及卫星导航技术进行研究,以完善多履带机械设计方法,提高其轨迹可控性并实现其自适应行驶是采矿装备大型化发展急需解决的关键课题。本文结合国家自然科学基金项目“多履带车辆机电耦合动力学及自适应控制”（No.51775225）和校企合作项目对六履带机械机电耦合动力学及卫星导航控制技术进行了研究,通过对六履带机械行驶力学分析,建立了六履带行走装置机电耦合动力学模型,进行了六履带机械行驶性能仿真,并通过试验对机电耦合模型及数值求解方法进行了验证;介绍了基于RTK的卫星导航原理,搭建了六履带机械路径跟踪控制系统试验平台,通过多种行驶工况以及不同初始偏差的实际追踪数据,验证了基于RTK卫星导航路径跟踪控制系统的控制效果。首先介绍了多履带行走装置的结构特点和驱动方式,综述了国内外有关多履带机械行驶动力学分析、机电耦合动力学、卫星导航控制以及履带车辆模糊PID控制方法的研究现状;结合六履带机械行走装置的结构特点和运动特性,建立了其直线行驶、稳态转向和非稳态转向的力学方程,并给出了数值求解方法。建立了三相异步电机的动态方程,分别建立了六履带机械直行工况与转向工况下的机电耦合动态方程,并通过数值计算分析了不同工况下履带机电参数的变化规律,分析了履带结构参数、驱动参数对行驶性能的影响。对六履带斗轮挖掘机的电机参数进行试验测试,验证了理论分析结果的正确。为实现对六履带机械典型行驶工况机电性能参数的计算和评价,开发了六履带机械行驶性能分析平台,该平台可分析不同履带布置方式、履带驱动形式对六履带机械稳态、非稳态转向特性的影响,计算相应的机电参数,并根据设计要求提供合理的六履带行走装置合理的结构参数。介绍了基于RTK的卫星定位导航原理,设计了六履带机械卫星导航径控制系统,以六履带机械实际行路径与预设路径之间的距离偏差和航向角偏差作为模糊PID控制器的输入,并根据机械的控制需要制定模糊规则,控制六履带机械转向履带组偏转角度和各条履带行驶速度,实现路径跟踪控制。建立了六履带机械虚拟样机模型,通过联合仿真分析了六履带机械直线行驶和曲线行驶工况下控制器对六履带机械的路径跟踪控制效果。结果表明,模糊PID控制器对六履带机械的路径跟踪控制具有良好的控制效果,六履带机械的实际行驶路径能够快速的收敛至预设路径,且进入稳定行驶时距离偏差和航向角偏差均保持在较小的范围内,满足自主导航的行驶的要求。为了进一步验证六履带机械卫星导航控制系统的控制效果,基于RTK导航技术,设计了六履带车辆卫星导航控制试验系统,主要由六履带试验样机、数据采集及处理系统、基于RTK导航的路径跟踪系统以及计算机控制系统组成,利用卫星定位信息获得预设路径导航线的轨迹。基于模糊PID控制方法,分别分析了试验样机实际行驶路径与预设路径之间的距离偏差和航向角偏差,试验结果验证了卫星导航控制系统具有较好的控制效果。综上所述,本文建立了六履带机械行驶力学模型及电耦合动力学模型,并通过试验进行了验证。开发了六履带机械行驶性能分析平台及基于卫星导航的六履带机械路径跟踪控制系统。论文的研究工作为完善六履带行走装置设计理论及提高六履带机械行驶的智能化水平提供了参考。

Feasible region detection is a critical problem in the field of intelligent driving. To solve the problem that the feasible region of vehicles is difficult to identify in the unstructured environment, a detection method based on the improved Random Sample Consensus (RANSAC) algorithm and Pyramidal Stereo Matching Network (PSMNet) is proposed in this paper. To overcome the influence of the complex environment and weather on the detection results, the 3D point cloud of the detection region is established to restore the actual scene. In contrast to the traditional stereo matching algorithm, the disparity map is obtained by the deep learning method PSMNet. Therefore, the 3D reconstruction of the detection region can be realized more accurately. Subsequently, the method of point cloud selection in RANSAC is redefined by constructing the k-dimensional tree (kd-tree) and using radius space density. Finally, the detection results of the feasible region are obtained by the improved RANSAC. It is tested in a variety of scenarios in complex environments and weather. The results demonstrate the high environmental adaptability and stability of the detection method. And compared with another method Segformer, the comparison results indicate that the method is effective in detecting road scenes under multiple weather conditions. © 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.

The development of autonomous detection technology is imperative in the field of construction. The bucket fill factor is one of the main indicators for evaluating the productivity of construction vehicles. Bucket detection is a prerequisite for bucket trajectory planning. However, previous studies have been conducted under ideal environments, a specific single environment, and several normal environments without considering the actual harsh environments at construction sites. Therefore, seven extreme environments are set in this paper to fill this gap, and an effective method is proposed. First, a novel framework for image restoration under extreme environments is proposed. It applies to all tasks conducted by vision on construction sites. Second, a combination of segmentation and classification networks is used for the first time in this area. Multitask learning is used to discover a positive correlation between fill factor estimation and bucket detection. Furthermore, probabilistic methods and transfer learning were introduced, and excellent results were achieved (97.40% accuracy in fill factor estimation and 99.76% accuracy in bucket detection for seven extreme environments).

Vehicle seats have a significant impact on the comfort of passengers. The development of seats is a field in which scholars are widely concerned. In this study, we add an electromagnetic levitation structure and design a new active seat suspension based on the passive seat suspension. Then, simulation research is carried out based on a C-level road surface combined with integral sliding mode control and state feedback control. The results show that both state feedback control and integral sliding mode control positively affect vehicle seat vibration reduction, and integral sliding mode control has a better anti-interference effect than state feedback control. At the same time, it is proved that the seat suspension has good working characteristics and economy. © 2022 by the authors.

To explore the performance of a semi-autogenous (SAG) mill under different working conditions, in this paper, the working process of the laboratory-scale SAG mill is taken as the research object. Firstly, the electrical system and multi-body dynamics model (EMBD) of the SAG mill are established, the rock discrete element method (DEM) analysis model is obtained based on the multi-sphere filling method, and then the DEM-EMBD coupling model is created, and its effectiveness is verified through actual experiments. Secondly, the influences of fraction of critical speed, lifter face angle, and rock shape on particle motion characteristics, particle collision energy, and mill torque are studied by the method of DEM-EMBD coupling method. The results show that the particle motion characteristics are mainly determined by fraction of critical speed and lifter face angle. Particle collision energy is mainly determined by lifter face angle and rock shape. Further, when the SAG mill runs at a low speed, the lifter face angle and rock shape become the main influencing factors of the mill torque, and the fraction of critical speed becomes the dominant factor with a high running speed of the SAG mill. Finally, the electromechanical characteristics of the SAG mill are analysed, and the results show that the fluctuation of motor load torque, current, and SAG mill speed in the start-up stage is much larger than that in the stable running stage. The fraction of critical speed and the lifter face angle have a greater impact on the electromechanical characteristics, while the rock shape has little influence on the electromechanical characteristics as a whole.

Vehicle seats have a significant impact on the comfort of passengers. The development of seats is a field in which scholars are widely concerned. In this study, we add an electromagnetic levitation structure and design a new active seat suspension based on the passive seat suspension. Then, simulation research is carried out based on a C-level road surface combined with integral sliding mode control and state feedback control. The results show that both state feedback control and integral sliding mode control positively affect vehicle seat vibration reduction, and integral sliding mode control has a better anti-interference effect than state feedback control. At the same time, it is proved that the seat suspension has good working characteristics and economy.