Keywords

1 Introduction

In recent years, countries all over the world attach great importance to the application of advanced technical groups with digital information technology as the core in the military field in the construction of military quality, and compete to develop high-tech weapons and equipment, and the key technology to realize this strategy is battlefield digitalization. The application of this technology in the field of armored vehicle platforms is reflected in the field of vehicle electronics. The application purpose of vehicle electronics technology is to transform the information among subsystems of combat vehicles from self-contained and disconnected to computer-based interconnection among systems in the vehicle (see [1]). In the field of armored fighting vehicles, the prerequisite for digitalization is vehicle electronics technology with digital transmission capabilities, including systems and components such as power control, communications, information/data management, computers, sensors, signal processing and fire control. With the rapid development of weapons and equipment in the world, the electronic system of combat and logistics vehicles is more and more valued by the military forces of various countries. The highly integrated and high-tech equipment and equipment forces are an inevitable trend and the electronic system of vehicles will also play an increasingly important role in the battlefield. The on-board display and control terminal, as the control centre of the vehicle, will monitor all the equipment in the vehicle in real time.

However, in different carriers, electronic equipment to withstand a variety of different degrees of vibration environment for a long time, the structure of electronic equipment will appear fatigue damage, causing its performance to decline, and even cause the damage of electronic equipment. In 1956, Lunney and Crede performed vibration analysis and fatigue analysis of electronic devices based on test data from real-world environments (see [2]). In 1973, Steinberg conducted a systematic analysis of the mechanical characteristics of electronic components from component level to system level electronic chassis in the book of vibration analysis for electronic equipment (see [3]). Finite element analysis technology was used to analyze and study the dynamic effects of surface-mount components (see [4]). Finite element analysis technique was used to study the dynamic response, dynamic strain and dynamic stress of printed boards (see [5]). Finite element analysis technology and experimental technology were used to analyze and calculate the dynamic response of printed boards under falling environment (see [6]). The research work carried out abroad mainly focuses on the object of components or printed boards, and the results obtained are also in these aspects, while the research on the system or product object is relatively rare, and the reference is limited. Domestic electronic equipment design and manufacturing managers have achieved a great development. The author systematically expounds the structural design and dynamic theory of the structure of electronic equipment, and systematically introduces the theory of vibration, shock and effective measures to reduce vibration in [7]. The author studies how to improve the anti-vibration and shock capability of electronic equipment from the perspective of the overall layout of electronic equipment and the structural design of the whole machine, and carried out optimization analysis on it in [8]. It can be seen that the domestic work on the structural dynamic response of electronic equipment is mainly focused on the system or the whole of the product, and the structural details of the components are relatively little considered, and the information available is limited.

2 Display Console Structure Scheme

Aiming at vehicle-mounted combat system and combat environment, this paper carries out research on vehicle-cabin integration, natural human–machine interaction, modeling design, human factor design, cable layout and environmental adaptability. The structure is simple and beautiful, the operation is convenient, and the maintenance is convenient. According to the installation space in the vehicle platform, the display console is adapted to change the leg part of the display console into an electronic cabinet unit, so as to provide installation space for user equipment and adopt the bottom cabinet design to improve the strength and stiffness of the overall structure of the display console. The 3D design software is used to simulate the human factor engineering of the display console. The finite element analysis software is used to simulate the mechanical test conditions of the display console. In addition, noise control and thermal design of the equipment are also carried out. In the design, we strictly follow the principles of generalization, serialization and combination design to ensure universality and extensibility.

The display console implements the design idea of generalization, serialization, modularization and combination. The display unit is composed of display unit, control unit and display control processing unit. The display unit mainly carries touch display and provides graphic image display and multi-touch function. The control unit mainly carries voice terminals, general control modules, etc., which can provide good human–computer interaction functions. The display and control processing unit carries the display and control computer and the power supply control module, and the cabinet unit mainly carries the task computer, network switch and user computer modules. In addition, the design of the display console fully considers the human factor engineering elements, adopts rounded corner design, and has no screws on the front, which can effectively improve the safety and comfort during use [9]. The layout of each unit of the display console is shown in Fig. 1.

Fig. 1
4 diagrams of the layout of the display console present 4 big panels in 2 rows. A, front view. B, left view. C, top view with keyboards. D, rear view.

The layout view of the display console

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Due to the limited space in the vehicle, in order to reduce the impact of equipment distribution on the space, the integrated design idea is adopted. The structural modeling of the display console is designed according to the space in the vehicle, and the wall-mounted installation method is adopted. The display console is connected and fixed by the bottom vibration isolator and the bottom plate of the vehicle, and the back vibration isolator and the frame beam are connected and fixed. Through the decorative parts, the display console can be integrated with the vehicle shell, the appearance is beautiful and simple, and the interior space can be maximized. The interior installation is shown in Fig. 2.

Fig. 2
A schematic diagram of the display console installed in the vehicle on the front side.

The view of the display console installed in the vehicle

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The display console carries out structural modeling design for the vehicle platform, adopts three-dimensional modeling technology to analyze the model of the vehicle display console, and focuses on the analysis of human factors including cockpit space, operator's body data measurement, field of vision, hand operation range, knee space and maintenance space. It can be seen that, this type of display console basically meets the requirements of integrated human factor engineering design. As shown in Fig. 3, the top view of the human-factor integration model shows that the spacing between the two cross-row seats is about 409 mm, which does not affect the traffic of personnel. In addition, the seat also has a folding or moving function to facilitate personnel access.

Fig. 3
A schematic diagram of the top view of chair spacing in an integrated model presents 2 human dummies sitting in a chair and using a console.

Top view of chair spacing in human-factor integrated model

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As can be seen from Fig. 4, the overall layout of the display console is reasonable, and the operation angle and hands of the personnel are accessible, which meets the requirements of human factors engineering design [10]. In addition, the operation table of the display console fully considers human factors engineering elements, adopts streamlined and rounded corners, and has high safety and comfort without screws on the front.

Fig. 4
2 schematic diagrams present 2 human dummies operating the integration model. A, stereo view. B, main view.figure 4

The view of operation in the human factor integration model

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Figure 5 is a schematic diagram of the knee space operated by the human integrated model personnel. It can be seen that the knee height is about 725 mm, the width is about 762 mm, and the depth is about 515 mm, which meets the requirements of “the height of the knee area is not less than 640 mm, the width is not less than 510 mm, and the depth is not less than 460 mm” in the specification. In addition, the display console operating table is sprayed with skin-friendly coating, which has the effect of anti-freezing and greatly improves the comfort of operators.

Fig. 5
2 schematic diagrams of the knee space area for operating the integration model. A, height space. B, width space between 2 seats.figure 5

The view of the knee area in the human factor integration model

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3 Electrical Cable Design

3.1 Routing Design of Display and Control Processing Unit

The following mechanism is arranged at the rear of the display and control computer, and the cable is bundled and fixed through a series of holes on the part. The two ends of the wire following mechanism are connected and fixed with the backplane of the display and control computer and the wall plate of the platform through hinges. The internal cable routing method of the display and control processing unit is attached to the cable binding belt at the rear of the chassis. Figure 6 shows the cable routing method.

Fig. 6
2 schematic diagrams of the internal wiring mode of the display and control processing unit represent some ports and wires. A, view 1. B, view 2.

The view of internal wiring mode of display and control processing unit

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3.2 Routing Design of Control Unit

The module cables embedded on the control console are routed along the cable channel on the lower surface of the control mesa panel. Standard cable fixation clips are set to facilitate cable fixation. The cables extend to the rear of the display console and connect to the rear connector of the di splay and control computer. The internal wiring mode of the control unit is shown in Fig. 7.

Fig. 7
A schematic diagram of the internal wiring mode of the control unit presents a panel with ports, wires, and other components.

The view of internal wiring mode of control unit

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3.3 Routing Design of Display Unit

The display cable extends downward along the cable trough and fixing device on the side wall of the display unit support, and enters the platform body through the connecting board at the rear of the display unit, and is connected with the corresponding navigation plug of the display and control computer. The back of the display unit is routed as shown in Fig. 8.

Fig. 8
A schematic diagram of the wiring mode on the back of the display unit presents a panel with wires and ports.

The view of the wiring mode on the back of display unit

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3.4 Routing Design of Cabinet Unit

Figure 9 shows the internal cabling of the cabinet unit.

Fig. 9
A schematic diagram of the wiring mode of the cabinet unit presents 3 panels with wires and incoming ports.

The view of the wiring mode of cabinet unit (using the right side as an example)

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4 Mechanical Design

4.1 Shock Analysis

According to the technical requirements document of the display console, the shock test conditions refer to the test grade 1 (10 g/3000 times) in GJB4.8-83 Environmental Test of Ship Electronic Equipment [11]. According to the regulations, the repetition frequency is 60–80 rpm and the shock pulse duration is ≥16 ms. In the calculation, the period duration of a single shock T is taken as 1 s, and the half-sine shock duration T are taken as 16 ms. The acceleration loading load within a single shock period is shown in Fig. 10 below, and the solution target is the stress curve at the position where the maximum stress occurs within a period.

Fig. 10
A point-to-point graph of acceleration in millimeters per square second versus time in seconds. It plots an inverted U-shaped trend that begins from (0, 0), ascends to a peak at (0.008, 100000), descends to (0.016, 0), and then remains at 0.

Input curve of the shock load

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Figure 11 shows the overall equivalent stress nephogram of the display console under the action of shock load. It can be seen that after the shock impact of the display console, the maximum stress of the overall structure is 57.62 MPa, which is far less than the allowable strength of the material, the maximum stress position is located in the lower left part of the display unit box and the control table bolt connection position, the overall structure is not in danger of damage, and the vast majority of the position stress is less than 5 MPa.

Fig. 11
A nephogram of the console shell plots the distribution of equivalent stress using a color gradient scale. The distribution is uniform at 3.066 times E minus 5.

Equivalent stress nephogram of shell during shock analysis

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In a shock period, the stress generated by the impact attenuates well after the impact. The whole structure can meet the strength requirements under the action of shock load.

4.2 Impact Analysis

According to the technical requirements document of the display console, the impact load is applied by referring to the test impact response spectrum used in GJB150.18A-2009 military equipment laboratory environmental test method impact test [12] when no measurement data is available—ground equipment Functional test (40 g). As shown in Fig. 12, the impact time is 15–23 ms, and here it is 21 ms, and the half-sine impact load is applied.

Fig. 12
A point-to-point graph of acceleration in millimeters per square second versus time in seconds. It plots an inverted U-shaped trend that begins from (0, 0), ascends to a peak at (0.0109, 400000) and descends to (0.021, 0).

Input curve of half sinusoidal impact load

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Vertical and 30-degree oblique impact response analysis was adopted for the display console. Figure 13 is the overall equivalent stress nephogram after the display console is subjected to vertical impact, and Fig. 14 is the overall equivalent displacement nephogram after the display console is subjected to vertical impact. After the display console is impacted in the vertical direction, the maximum stress of the overall structure is 162.99 MPa, which is less than the allowable strength of the material. The maximum stress is located at the bolt connection position of the stage body and the stage body, and the overall structure does not fail to damage.

Fig. 13
A nephogram of the console shell plots the distribution of equivalent stress using a color gradient scale. The distribution is mostly uniform at 3.066 times E minus 5 with a gradient between 1.088 times E 1 and 1.63 times E 2 below the display panels.

Equivalent stress nephogram of shell during vertical impact analysis

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Fig. 14
A nephogram of the console shell plots the distribution of equivalent displacement using a color gradient scale. The distribution at the base is between 1.514 times E 1 and 2.019 times E 1. The distribution in the center is between 0 and 7.57. The distribution at the top is between 1.009 times E 1 and 2.019 times E 1.

Equivalent displacement nephogram of shell during vertical impact analysis

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Compared with the initial position, the maximum displacement is 22.71 mm, located on the upper panel of the lower box, within the safe displacement range.

Figure 15 is the overall equivalent stress nephogram after the display console is subjected to 30° oblique impact, and Fig. 16 is the overall equivalent displacement nephogram after the display console is subjected to 30° oblique impact. After the display console is impacted by the tilt of 30°, the maximum stress of the overall structure is 187.97 MPa, which is less than the allowable strength of the material. The maximum stress is located at the bolt connection position of the stage body and the stage body, and the overall structure does not fail to damage.

Fig. 15
A nephogram of the console shell plots the distribution of equivalent stress using a color gradient scale. It presents the impact on the front side of the console.

Equivalent stress nephogram of shell during 30° oblique impact analysis

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Fig. 16
A nephogram of the console shell plots the distribution of equivalent displacement using a color gradient scale. The distribution at the base is between 1.938 times E 1 and 2.215 times E 1. The distribution in the center is between 0 and 5.537. The distribution at the top is between 8.305 and 1.938 times E 1.

Equivalent displacement nephogram of shell during 30° oblique impact analysis

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Compared with the initial position, the maximum displacement is 24.92 mm, located on the upper panel of the lower box, within the safe displacement range.

Under the impact load, the stress produced by the impact decays well after the impact. The overall structure of the display console can meet the strength requirements under the impact load.

5 Conclusions

Based on the mature design technology of display console, make full use of 3D design software and simulation analysis software, optimize and analyze the main design parameters of display console, and the technology is reliable. The scheme meets the technical requirements of the display console, strictly follows the design principles of universality, serialization and combination, and strictly follows the design requirements of reliability, maintainability, environmental adaptability, electromagnetic compatibility and structural manufacturability. The scheme is reasonable and feasible.