Equivalent Test Method for Strong Electromagnetic Field Radiation Effect of EED

The present study proposed the equivalent test method for the strong electromagnetic field radiation of electric explosive devices (EEDs) of the weapon equipment to satisfy the military requirements of the electromagnetic radiation safety test, as well as the evaluation of the electric ignition, the electric initiation ammunition, or missiles. Under stable conditions, the ignition excitation test and the bridge wire temperature increase test were performed to determine the ignition temperature of the EED. As radiated by the strong electromagnetic field, the relationship between the temperature increase of the bridge wire and the electric field intensity of the EED was developed based on the theoretical analysis and the experimental test. Given the ignition temperature of the EED, the radiation field intensity of the EED at 50% ignition was determined. As compared with the 50% ignition field intensity of the EED directly radiated by the strong electromagnetic field, an error less than 1 dB was caused. On that basis, the correctness of the equivalent test method was verified. Accordingly, this method was suggested to act as an effective method and technical means to test and evaluate the electromagnetic radiation safety of ammunition and missiles in unfavorable electromagnetic environments.

Research on the Effect of Metal Electrode Coupling Voltage under Induced Electrostatic Discharge

In this paper, the mechanism of electrostatic discharge induced by a strong electromagnetic field was studied through software simulation and test verification. By focusing on the effect mechanism of coupling voltage between metal electrodes to induce electrostatic discharge, we obtained the law of electrostatic discharge induced by the strong electromagnetic field. In the process of electrostatic discharge induced by the strong electromagnetic field, due to the antenna receiving effect of metal electrode structure, the strong electromagnetic field would form coupling induction voltage on the metal electrode. The voltage acts on both ends of the discharge electrode structure and generates an electric field in the gap between the electrode structure, which superimposes on the original field; furthermore, it has an impact on the electrostatic discharge process, resulting in the formation of induced discharge with low charging voltage structure.

Healing of cracks in plates by strong electromagnetic field

Рассматривается задача о воздействии импульсным высокоэнергетическим электромагнитным полем на краевую трещину в тонкой пластине, воспроизводящая пионерский эксперимент советских ученых по разрушению вершины трещины сильным электромагнитным полем. Численное моделирование осуществляется на основе предложенной электромеханической модели воздействия короткоимпульсным высокоэнергетическим электромагнитным полем на материал с трещиной. Модель учитывает фазовые превращения (плавление и испарение) материала, происходящие в окрестности дефектов, и соответствующие изменения реологии материала в областях этих трансформаций, а также возможность протекания электрического тока между свободными поверхностями трещины (пробоя за счет эмиссии электронов). Все физико-механические характеристики материала считаются зависящими от температуры. Уравнения модели связаны и решаются совместно на подвижной конечно-элементной сетке с применением смешанного метода Эйлера-Лагранжа. Исследуются процессы локализации полей плотности тока и температуры, фазовых превращений (плавления и испарения) в вершине трещины, автоэлектронной и термоэлектронной эмиссии между свободными поверхностями трещины и влияние этих процессов на залечивание трещины. Проводится сравнение результатов моделирования с имеющимися экспериментальными данными по воздействию импульсного поля на краевую трещину в пластине. Полученные в окрестности вершины трещины средняя скорость нагрева металла и градиенты температуры неплохо количественно согласуются с экспериментальными данными. Вдали от трещины, а также на берегах трещины вдали от вершины температура поднималась незначительно. Процесс моделирования воздействия электромагнитным полем, аналогично эксперименту, сопровождается плавлением в вершине трещины, а также испарением металла. Таким образом, при рассматриваемом воздействии током в вершине трещины формируется кратер, который препятствует дальнейшему распространению трещины, приводя к ее залечиванию. Получить аналогичные результаты с помощью ранее предложенных моделей не удавалось.

Motion posture control for power cable maintenance robot in typical operation conditions

Purpose In the extreme power environment of flexible transmission line, wind load, high voltage and strong electromagnetic interference, the motion performance of the robot manipulator is strongly affected by the extreme environment. Therefore, this study aims to improve the manipulator motion control performance of power cable maintenance robot and effectively reduce the influence of specific operation environment on the robot manipulator motion posture. Design/methodology/approach The mathematical model under three typical operation conditions, namely, flexible line, wind load and strong electromagnetic field have been established, correspondingly the mapping relationship between different environment parameters and robot operation conditions are also given. Based on the nonlinear approximation feature of neural network, a back propagation (BP) neural network is adopted to solve the posture control problems. The power cable line sag, robot tile angle caused by wind load and spatial field strength are the input signals of the BP network in the robot motion posture control method. Findings Through the training and learning of the BP network, the output control variables are used to compensate the actual robot operation posture. The simulation experiment verifies the effectiveness of the proposed algorithm, and compared with the conventional proportional integral differential (PID) control, the method has high real-time performance and sound stability. Finally, field operation experiments further validate the engineering feasibility of the control method, and at the same time, the proposed control method has the remarkable characteristics of sound universality, adaptability and easy expansion. Originality/value A multi-layer control architecture which is suitable for smart grid platform maintenance is proposed and a robot system platform for network operation and maintenance management is constructed. The human–machine–environment coordination and integration mode and intelligent power system management platform can be realized which greatly improves the intelligence of power system management. Mathematical models of the robot under three typical operation conditions of flexible wire wind load and strong electromagnetic field are established and the mapping relationship between different environmental parameters and the robot operation conditions is given. Through the non-linear approximation characteristics of BP network, the control variables of the robot joints can be obtained and the influence of extreme environment on the robot posture can be compensated. The simulation results of MATLAB show that the control algorithm can effectively restrain the influence of uncertain factors such as flexible environment, wind load and strong electromagnetic field on the robot posture. It satisfied the design requirements of fast response, high tracking accuracy and good stability of the control system. Field operation tests further verify the engineering practicability of the algorithm.