비만아 부모의 돌봄 경험: q 방법론

The lateral stability is the crucial feature in a distributed drive electronic vehicle (DDEV). A high speed DDEV in a sharp turn may lose the lateral stability when it encounters fast varied road adhesion coefficients. To solve this problem, a BP-PID controller-based multi-model control system (MMCS) is designed for DDEV via direct yaw-moment control (DYC) in this paper. Firstly, according to the varied road adhesion coefficients, the working circumstance of DDEV is summarized as seven kinds of typical types. A sub-model set is established to accurately describe the operating mode of the working circumstance. Secondly, based on the sub-model set, a nonlinear sub-controller set is constructed with seven off-line tuning BP-PID controllers and an on-line tuning one. The off-line tuning controller can fast calculate the required direct yaw-moment, and the on-line tuning controller is aimed to achieve a high control accuracy. Thirdly, a controller switching policy is composed of an error judgement policy and a model matching policy. Such switching policy is utilized to precisely identify the working circumstance of DDEV and implement switching control. Finally, simulation experiments prove that the designed MMCS shows a significant control performance and guarantees the lateral stability of DDEV under varied road adhesion coefficients.

A BP-PID Controller-Based Multi-Model Control System for Lateral Stability of Distributed Drive Electric Vehicle

Ultrasonic assisted incremental sheet forming: Constitutive modeling and deformation analysis

Lightweight materials, such as titanium alloys, magnesium alloys, and aluminium alloys, are characterised by unusual combinations of high strength, corrosion resistance, and low weight. However, some of the grades of these alloys exhibit poor formability at room temperature, which limits their application in sheet metal-forming processes. Lightweight materials are used extensively in the automobile and aerospace industries, leading to increasing demands for advanced forming technologies. This article presents a brief overview of state-of-the-art methods of incremental sheet forming (ISF) for lightweight materials with a special emphasis on the research published in 2015–2021. First, a review of the incremental forming method is provided. Next, the effect of the process conditions (i.e., forming tool, forming path, forming parameters) on the surface finish of drawpieces, geometric accuracy, and process formability of the sheet metals in conventional ISF and thermally-assisted ISF variants are considered. Special attention is given to a review of the effects of contact conditions between the tool and sheet metal on material deformation. The previous publications related to emerging incremental forming technologies, i.e., laser-assisted ISF, water jet ISF, electrically-assisted ISF and ultrasonic-assisted ISF, are also reviewed. The paper seeks to guide and inspire researchers by identifying the current development trends of the valuable contributions made in the field of SPIF of lightweight metallic materials.

Emerging Trends in Single Point Incremental Sheet Forming of Lightweight Metals

With the more and more complexity demands of the market, the geometric accuracy of the part has become the main factor restricting the development of single point incremental forming technology (SPIF). For this reason, with the truncated cone as the target part, the radial accuracy error generation mechanism was analyzed from the aspects of sheet springback and residual stress distribution. Four factors and three levels of surface response experiments were designed using the Box-Behnken Design (BBD) for tool head diameter, layer spacing, sheet thickness, and wall angle. The single and interactive influence law of the process parameters on the radial accuracy was obtained. In response to the above research results, the ultrasonic vibration was introduced into the process of SPIF to reduce springback by reducing residual stress. The influence of vibration parameters on the accuracy was obtained through experiments. The results showed that ultrasonic vibration could effectively improve and control the accuracy of the part.

/pdf/research-on-the-radial-accuracy-of-ultrasonic-vibration-wh5onqv46r.pdf

Research on the Radial Accuracy of Ultrasonic Vibration-Assisted Single Point Incremental Forming Parts

Fault diagnosis for quality control during the multivariate production process is widely used to detect abnormal fluctuations, find out failure reasons and take measures to maintain the stability of the production system accordingly. The neural network methodology has become a main method in the field of intelligent diagnosis recently. However, it has certain deficiencies such as longer training time, slower convergence rate and easier falling into a local optimal solution easily. As a result, the effect of fault diagnose is influenced. Thus, this article proposes the idea of using the Fruit Fly Optimization Algorithm in the multivariable process fault diagnosis model, at the same time, to analyze the out of control sample data in the automobile crankshaft production. Compared with the neural network model in dealing with the fault diagnosis in multivariate process, Fruit Fly Optimization Algorithm’s effectiveness s verified.

http://www.sersc.org/journals/IJUNESST/vol8_no1/31.pdf

FOA Based Diagnosis Model for Multivariate Production Process

Deformation Force Simulation of Lead Screw Cold Roll-beating

http://or.nsfc.gov.cn/bitstream/00001903-5/74045/1/1000005023439.pdf

Study on the Metal Flowing of Lead Screw Cold Roll-Beating Forming

The cutting-press shaping technique is a green technology for manufacturing some functional surfaces such as fin-tubes. The correct selecting and matching of the technological parameters and cutting tool angles are of critical to shape the fins. Based on experiments, design principles of the cutting tool are put forward, the influencing laws of the rake angle, relief angle, main deflection angle, blade obliquity of the major cutting edge and assistant deflection angle, assistant rake angle, assistant relief angle of the minor cutting edge on the fins forming are analyzed, and the reasonable angles selecting ranges are given, which are verified by the experiments.

Yang Mingshun

Papers

Research on the Radial Accuracy of Ultrasonic Vibration-Assisted Single Point Incremental Forming Parts

FOA Based Diagnosis Model for Multivariate Production Process

Deformation Force Simulation of Lead Screw Cold Roll-beating

Study on the Metal Flowing of Lead Screw Cold Roll-Beating Forming

Tool design of fin-tube cutting-press shaping