Pilot workload evaluation method and system based on task complexity analysis

Abstract

The present invention adopts a discrete event simulation method to create a flight mission network, combines multi-resource theory, VACP theory, and visual coding theory, and uses a simulation software platform Matlab Simulink to analyze the flight mission multi-channel resources from a top-down perspective. A pilot workload calculation unit based on flight mission complexity analysis is constructed, and a pilot workload calculation unit based on interface complexity is constructed from a bottom-up perspective of multi-visual coding of a flight interface. Finally, a pilot workload evaluation system for flight mission complexity and interface design complexity analysis is constructed, which includes four submodules: flight mission complexity input, interface design complexity input, workload evaluation, and output report. The system predicts workload change trends in different mission change processes and different cockpit interface design states, thereby providing an effective means for improving pilot work efficiency and improving flight operation safety.

Description

Technical Field

[0001] The invention relates to a pilot workload evaluation method and system based on task complexity analysis. Background Art

[0002] In aviation safety, human factors are one of the most likely causes of accidents. Among them, information acquisition and analysis errors and decision-making errors caused by excessive workload are the main causes of accident symptoms and accidents. Workload reflects the psychological pressure generated when performing tasks under specific environmental and operating conditions, as well as the operator's ability to respond to these demands, including task requirements, performance levels, operator psychological and physiological efforts, and operator perception. Under different circumstances, the relationship between the operator's workload, task difficulty, and performance level will present different states. The inverted "U" model is usually used to describe the relationship between the three. Too high or too low workload is not conducive to the completion of the task. Only when the workload is kept at an appropriate level can the operator achieve the best task performance.

[0003] According to different natures, it can be divided into two categories: mental workload and physiological workload. Physical workload refers to the amount of physical effort an operator exerts to meet performance requirements, which is generally proportional to the operator's oxygen consumption; mental workload refers to the amount of attention an operator devotes to meet performance requirements, reflecting an individual's subjective feelings when performing a specific task under specific environment and time constraints. Workload is affected by many factors, such as environment, tasks, and characteristics of operators. In the field of pilots, factors such as task complexity, different flight phases, flight experience, and flight environment will all have an impact on workload.

[0004] Workload assessment methods are mainly divided into three categories, namely physiological measurement methods, subjective measurement methods and task measurement methods. Physiological measurement methods are methods based on the physiological response of the body, and indicators include eye movement indicators, EEG indicators, breathing indicators, ECG indicators, etc. Subjective measurement methods are to measure the subjective feelings of operators to evaluate the workload level. Commonly used methods include: NASA-TLX scale, SWAT scale, revised MCH scale, Bedford load scale, etc. Task measurement methods evaluate and measure workload by measuring the performance of individuals in tasks, or measuring the changes in individual performance when the workload is increased. Task measurement can usually be divided into primary task measurement methods and secondary task measurement methods. In the study of pilot workload, the main indicator used by the primary task method is flight performance. Commonly used methods of secondary task measurement methods include time estimation tasks, memory tasks, search tasks, etc. Among them, the secondary task that is considered to have a better effect is time estimation.

[0005] Task complexity is considered to be a key factor in determining information processing, cognitive load, decision-making strategy, goal setting effect, and intrinsic motivation and satisfaction of task performers. It affects pilot workload and operational performance. Most studies believe that task complexity has a negative effect on performance, that is, operational performance will decrease with the increase of task complexity, and it will be manifested as longer operation time and higher operation error rate. Therefore, adding complexity to the model can better predict workload.

[0006] The human-machine interface of the aircraft cockpit is an important device for human-machine interaction between pilots and aircraft. In recent years, more and more advanced technologies have been used to equip aircraft. The aircraft cockpit interface has begun to tend to be displayed on a large LCD screen. Large integrated photoelectric information displays have replaced multiple decentralized mechanical instruments in the past, greatly increasing the complexity of interface design and leading to an increase in the workload of pilots in flight operations. Therefore, studying the complexity of interface design can provide a theoretical basis for improving the excessive workload associated with the complexity of interface design. One of the important contents of aircraft cockpit human-machine interface design is visual coding. The method of using different visual stimuli or stimulus attributes to express different meanings is called visual coding. Single-dimensional visual coding includes color coding (using color hue, brightness, and saturation for information coding), number and letter coding (using numbers and letters as codes for information coding), and geometric figure coding (using geometric shape features as codes for information coding, such as area, line length, inclination, etc.). Multidimensional visual coding refers to a coding method that combines two or more visual attributes. The code systems that may be combined include color, numbers and letters, shape, size, brightness, position, flash speed, line length, bevel, etc. The quality of visual coding design will affect pilot performance and flight safety. The instrument display interface reasonably uses visual stimuli such as colors, numbers, letters, text, and graphics to encode information. If it can ensure that the pilot can quickly and accurately recognize flight information in various flight tasks, it will greatly reduce the reaction time of these tasks, thereby reducing mental workload and improving work performance.

[0007] By studying the calculation and analysis methods of pilot workload and maintaining it at an appropriate level, it is beneficial to improve the pilot's work efficiency and the reliability of flight operations. Most of the existing technologies remain at the four-channel scoring scale, and lack research on the combination of two complexities. Summary of the invention

[0008] The inventors of the present invention recognize that, since complexity is closely related to workload, by introducing complexity analysis into the workload model and simultaneously considering the impact of the flight mission complexity and interface design complexity dimensions, the accuracy of workload quantification can be improved and the reliability of the model can be improved.

[0009] The present invention provides a pilot workload evaluation system based on task complexity analysis, which includes four submodules, namely: flight mission complexity input module, interface design complexity input module, workload evaluation module, and output report module. The flight mission complexity input module includes flight mission network establishment and task channel assignment; the interface design complexity input module is used to input relevant indicators of interface design complexity, and five visual codes including display characters, color matching, layout position, flickering and information flow intensity are selected as evaluation indicators; the workload evaluation module is mainly used to analyze and evaluate the input task-related data, and includes three modules: task parameter preprocessing module, task complexity calculation module, and comprehensive workload evaluation module; the output report module is used to save and comprehensively output the pilot workload evaluation results.

[0010] The beneficial effects and advantages of the present invention include:

[0011] The present invention is based on the analysis and research of the calculation and analysis method of pilot workload, introduces task complexity analysis into the workload model, and considers the influence of the dimensions of flight mission complexity and interface design complexity at the same time, thereby realizing the pilot workload assessment based on task complexity analysis, improving the accuracy of workload quantification, and providing an effective means for improving the pilot's work efficiency and / or improving the reliability of flight operations.

[0012] Advantages and beneficial effects of the present invention further include:

[0013] (1) By introducing the extended VACP (Visual, Auditory, Cognitive, Psychomotor) method, multi-resource channel assignment of task complexity was performed. On the basis of the traditional four channels of vision, hearing, cognition, and movement, speech and touch were added. At the same time, the movement was refined into gross movement and fine movement. Seven modeling channels were used, which improved the task diversity compared with the traditional four channels.

[0014] (2) In terms of task complexity, the influence of two dimensions, namely, the complexity generated by flight task attributes from top to bottom and the complexity generated by interface design attributes from bottom to top, is considered simultaneously. On the one hand, the simulation software platform Matlab Simulink is used to construct a pilot workload calculation unit based on flight task complexity analysis, aiming at the top-down analysis of multi-channel resources of flight tasks. On the other hand, from the bottom-up analysis of multi-visual coding of flight interfaces, a pilot workload calculation unit based on interface complexity is constructed. Then, a pilot workload model is constructed for the analysis of flight task complexity and interface design complexity. This model can calculate and predict the workload change trend of different task change processes and different cockpit interface design states. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is an overall architecture diagram of a pilot workload evaluation system based on task complexity analysis according to an embodiment of the present invention;

[0016] Figure 2 is a partial schematic diagram of a flight network generated after inputting task parameters into a pilot workload evaluation system based on task complexity analysis according to an embodiment of the present invention;

[0017] Figures 3(a) to 3(d) It is a schematic diagram of the user interface of a pilot workload evaluation system based on task complexity analysis in various operating states according to an embodiment of the present invention. DETAILED DESCRIPTION

[0018] 1. General Overview

[0019] The present invention adopts a discrete event simulation method to create a flight mission network, and combines multi-resource theory, VACP theory, visual coding theory, etc. On the one hand, for the top-down analysis of multi-channel resources of flight missions, a simulation software platform Matlab Simulink is used to construct a pilot workload calculation unit based on flight mission complexity analysis; on the other hand, from the bottom-up analysis of multi-visual coding of flight interfaces, a pilot workload calculation unit based on interface complexity is constructed, and finally a pilot workload evaluation system for flight mission complexity and interface design complexity analysis is constructed to predict workload change trends in different task change processes and different cockpit interface design states.

[0020] 2 Pilot workload evaluation system architecture based on task complexity analysis

[0021] like Figure 1As shown, the pilot workload evaluation system based on task complexity analysis according to an embodiment of the present invention includes four modules: a flight mission complexity input module, an interface design complexity input module, a workload evaluation module, and an output report module. Specific descriptions are as follows.

[0022] (1) Flight mission complexity input module

[0023] This module consists of two parts, namely the flight mission network establishment part and the mission channel assignment part.

[0024] ① The flight mission network establishment part is used to: input the task name, task description, task time and other information of each specific task, and connect the tasks according to the logical relationship between the tasks to establish the flight mission network;

[0025] ②The task channel assignment part is used to assign values ​​to each channel of each task according to the seven channels of vision, audition, cognition, fine motor, gross motor, speech and tactile in the expanded VACP theory, combined with the actual task situation. The assignments corresponding to the task description features are shown in the following table.

[0026]

[0027]

[0028] (2) Interface design complexity input module

[0029] This module is used to input relevant indicators of interface design complexity, and input parameters according to the situation of the aircraft cockpit display interface. Five visual codes, display characters, color matching, layout position, flickering, and information flight mission complexity flow intensity, are selected as evaluation indicators, among which:

[0030] ① Display characters include: a. Character size, which mainly refers to the height of characters in the display interface; b. Character types, including Chinese, English, numbers, geometric symbols, etc. English also distinguishes between uppercase and lowercase, and Chinese distinguishes between simplified and traditional characters, etc.; c. Font shape, that is, various fonts of characters such as Chinese, English, numbers, etc.; d. Stroke width, including the thickness of the strokes of tick marks, pointers, characters, etc.;

[0031] ② Color matching includes: matching of background color and target color, such as black background and white text; matching of sky and earth colors in attitude indicator; and the background color of the entire main flight display interface, such as black or the color of attitude indicator;

[0032] ③Layout position includes: the position of flight information on the display interface, and the shape of scale lines, such as bar scale lines and arc scale lines;

[0033] ④ Flashing includes: during the flight, the flight information flashes at a certain frequency (such as warning status), which is an important prominent design method;

[0034] ⑤Information flow intensity includes: the amount of information and the frequency of information display. The intensity of information flow directly affects the flight workload.

[0035] (3) Workload Assessment Module

[0036] This module is mainly used to analyze and evaluate the input mission-related data, and includes four submodules: mission parameter preprocessing module, flight mission complexity calculation module, interface design complexity calculation module, and comprehensive workload evaluation module. Among them:

[0037] ① Mission parameter preprocessing module, which preprocesses the input parameters of the relevant mission and constructs a flight mission network with detailed parameters. The structural diagram of the flight mission network is shown in the figure. Figure 2 As shown in the figure. The flight mission network includes parameters such as the mission sequence, the logical relationship between different tasks, the mission content and attributes, and the assignment of different mission channels. For example, after the "monitor airspeed indicator" mission, the "pull the lever for takeoff" and "monitor the altimeter" mission are performed simultaneously. The assignments of the seven channels of the "monitor airspeed indicator" mission are 4, 0, 5, 0, 0, 0, 0.

[0038] ②The mission complexity calculation module is used to integrate the flight mission complexity calculation and the interface design complexity calculation into the mission complexity calculation, including: the flight mission complexity calculation part, which is used to perform flight mission complexity calculation based on the multi-information processing channel decomposition and meta-operation analysis of the multi-resource theory; the interface design complexity calculation part, which is used to use the integrated performance value (Integrated Performance Values, IPVs) method to normalize and quantify the feature values ​​of multi-dimensional visual coding, select five visual codings including display characters, color matching, layout position, flicker and information flow intensity as evaluation indicators and calculate the interface design complexity according to their weight coefficients.

[0039] ③ The comprehensive workload assessment module is used to combine the multi-resource theory and VACP theory to calculate and assess the pilot's workload during the mission. The calculation formula is shown below:

[0040]

[0041] Among them, i and j represent different cognitive processing channels, WL represents workload, and the sum upper limit 7 represents that there are seven channels in the VACP theory; ai 、b j represents the resource requirements of cognitive processing channels i and j for tasks a and b, c ij It represents the conflict coefficient between cognitive processing channels i and j. For single-task flight conditions, the pilot workload includes the sum of the resources of each cognitive processing channel. The workload calculation under multi-task conditions includes two parts: the first part is to calculate the workload of the task itself by calculating the sum of the cognitive processing channel resource requirements of each task; the second part is to calculate the increased workload caused by the conflict by calculating the cognitive resources increased by the conflict between cognitive processing channels (only the first part needs to be calculated under single-task conditions). Finally, a comprehensive assessment of the pilot workload is achieved.

[0042] (4) Output report module

[0043] It is used to comprehensively output the task complexity and pilot workload results assessed in the above modules, where the task complexity can be output in the form of a line graph, and the pilot workload can be output in the form of a task time series graph (Gantt chart) and a workload result ladder graph. It can support selecting a specified path to save and export the data list.

[0044] 3. Operation method of pilot workload evaluation based on the user interaction interface of the pilot workload evaluation system based on task complexity analysis

[0045] like Figures 3(a) to 3(d) FIG. 1 is a schematic diagram of a user interface of a pilot workload evaluation system based on task complexity analysis in various operating states according to an embodiment of the present invention.

[0046] The input part includes flight mission complexity input and interface design complexity input. The flight mission complexity input interface is shown in Figure 3(a), titled "Pilot Workload Evaluation System", and the input content includes task name, task description, task priority, task time and channel assignment, as well as three buttons: "OK", "Cancel" and "Close". The interface design complexity input interface is shown in Figure 3(b), and the input content includes five visual encodings: display characters, color matching, layout position, flashing and information flight mission complexity flow intensity. The user selects the specific form of each indicator, and the system will present the corresponding score.

[0047] The result output part is shown in Figure 3(c) and Figure 3(d), including the task time series diagram (Gantt chart) and the workload result ladder diagram. It contains three buttons: "Save", "Export" and "Close", which can support the selection of a specified path to save and export the data list.

Claims

1. Pilot workload evaluation system based on task complexity analysis, characterized by include: The flight mission complexity input module includes: The flight mission network establishment part is used to input the information of each specific mission, and connect the tasks according to the logical relationship between the tasks to establish the flight mission network. The information includes the mission name, mission description, and mission time. The task channel assignment part is used to assign task description features to each channel of each task based on the seven channels of vision, hearing, cognition, fine motor, gross motor, speech and touch, combined with the actual task situation. The interface design complexity input module is used to input relevant indicators of interface design complexity. The parameters are input according to the situation of the aircraft cockpit display interface, including selecting five visual codes such as display characters, color matching, layout position, flickering, and information flow intensity as evaluation indicators. The workload assessment module is used to analyze and evaluate the input task-related data, including: The task parameter preprocessing submodule is used to preprocess the input parameters of the relevant tasks and build a flight task network with detailed parameters. The flight task network includes the task sequence, the logical relationship between different tasks, the task content and attributes, and the assignment parameters of different channels of the task. The mission complexity calculation submodule is used to integrate the flight mission complexity calculation and the interface design complexity calculation into the mission complexity calculation, including: The flight mission complexity calculation part is used for multi-information processing channel decomposition and meta-operation analysis based on multi-resource theory to calculate the complexity of the flight mission; The interface design complexity calculation part is used to normalize and quantify the feature values ​​of multi-dimensional visual coding using the comprehensive performance method, select five visual codings including display characters, color matching, layout position, flickering and information flow intensity as evaluation indicators and calculate the interface design complexity according to their weight coefficients. The comprehensive workload assessment submodule is used to calculate and assess the workload of pilots during the mission, and to achieve a comprehensive assessment of the pilot's workload. The calculation formula is: Where i and j represent different cognitive processing channels, WL represents workload, the sum upper limit 7 corresponds to the seven channels, and a i 、b j represents the resource requirements of cognitive processing channels i and j for tasks a and b, c ij represents the conflict coefficient between cognitive processing channels i and j, where: for single-task flight conditions, the pilot workload includes the sum of the resources of each cognitive processing channel; for multi-task conditions, the workload calculation includes two parts: the first part is to calculate the workload of the task itself by calculating the sum of the cognitive processing channel resource requirements of each task; the second part is to calculate the increased workload caused by the conflict by calculating the cognitive resources increased by the conflict between cognitive processing channels; The output report module is used to comprehensively output the task complexity and pilot workload results assessed in the above modules.

2. The pilot workload evaluation system based on task complexity analysis according to claim 1, characterized in that: The assignment of task description features includes:

3. The pilot workload evaluation system based on task complexity analysis according to claim 1, characterized in that: Display characters include: a. Character size refers to the height of characters in the display interface; b. Character types, including Chinese, English, numbers, and geometric symbols. English also distinguishes between uppercase and lowercase, and Chinese distinguishes between simplified and traditional characters; c. Font glyphs, i.e. various fonts of characters; d. Stroke width, including the thickness of the strokes of tick marks, pointers, and characters; Color matching includes: Matching of background color and target color; Matching of sky and earth colors in the posture instrument; The background color of the entire primary flight display interface; Layout locations include: The location of flight information on the display interface; Tick ​​mark shape; Flashes include: During the flight, the flight information flashes at a certain frequency, which is an important prominent design method; Information flow strength includes: The number of messages and how often they are displayed.

4. The pilot workload evaluation system based on task complexity analysis according to claim 1, characterized in that: The task complexity is output as a line graph. The pilot workload is output in the form of a task time series diagram and a workload result ladder diagram, and supports selecting a specified path to save and / or export the data list.

5. The pilot workload evaluation method based on task complexity analysis is characterized by include: The steps for inputting the complexity of flight missions include: Establishing a flight mission network, including inputting information of each specific mission, and connecting the tasks according to the logical relationship between the tasks to establish the flight mission network, wherein the information includes the mission name, mission description, and mission time; Task channel assignment includes assigning task description features to each channel of each task based on the seven channels of vision, hearing, cognition, fine motor, gross motor, speech and touch, combined with the actual task situation. The interface design complexity input step is to input the relevant indicators of interface design complexity, and input parameters according to the situation of the aircraft cockpit display interface, including selecting five visual codes such as display characters, color matching, layout position, flickering, and information flow intensity as evaluation indicators. The workload assessment step is to analyze and evaluate the input task-related data, including: The task parameter preprocessing sub-step preprocesses the input parameters of the relevant tasks and constructs a flight task network with detailed parameters. The flight task network includes the task sequence, the logical relationship between different tasks, the task content and attributes, and the assignment parameters of different channels of the task. The task complexity calculation sub-step integrates the flight task complexity calculation and the interface design complexity calculation into the task complexity calculation, including: Flight mission complexity calculation: based on the decomposition of multiple information processing channels and meta-operation analysis of multi-resource theory, flight mission complexity calculation is performed; The interface design complexity calculation uses the comprehensive performance method to normalize and quantify the feature values ​​of multi-dimensional visual coding, selects five visual codings, including display characters, color matching, layout position, flickering, and information flow intensity, as evaluation indicators, and calculates the interface design complexity according to their weight coefficients. The comprehensive workload assessment sub-step calculates and assesses the pilot's workload during the mission to achieve a comprehensive assessment of the pilot's workload. The calculation formula is: Where i and j represent different cognitive processing channels, WL represents workload, the sum upper limit 7 corresponds to the seven channels, and a i 、b j represents the resource requirements of cognitive processing channels i and j for tasks a and b, c ij represents the conflict coefficient between cognitive processing channels i and j, where: for single-task flight conditions, the pilot workload includes the sum of the resources of each cognitive processing channel; for multi-task conditions, the workload calculation includes two parts: the first part is to calculate the workload of the task itself by calculating the sum of the cognitive processing channel resource requirements of each task; the second part is to calculate the increased workload caused by the conflict by calculating the cognitive resources increased by the conflict between cognitive processing channels; The output report step comprehensively outputs the task complexity and pilot workload results assessed in the above steps.

6. The pilot workload evaluation method based on task complexity analysis according to claim 5 is characterized by: The assignment of task description features includes:

7. The pilot workload evaluation method based on task complexity analysis according to claim 5 is characterized by: Display characters include: a. Character size refers to the height of characters in the display interface; b. Character types, including Chinese, English, numbers, and geometric symbols. English also distinguishes between uppercase and lowercase, and Chinese distinguishes between simplified and traditional characters; c. Font glyphs, i.e. various fonts of characters; d. Stroke width, including the thickness of the strokes of tick marks, pointers, and characters; Color matching includes: Matching of background color and target color; Matching of sky and earth colors in the posture instrument; The background color of the entire primary flight display interface; Layout locations include: The location of flight information on the display interface; Tick ​​mark shape; Flashes include: During the flight, the flight information flashes at a certain frequency, which is an important prominent design method; Information flow strength includes: The number of messages and how often they are displayed.

8. The pilot workload evaluation method based on task complexity analysis according to claim 5 is characterized by: The task complexity is output as a line graph. The pilot workload is output in the form of a task time series diagram and a workload result ladder diagram, and supports selecting a specified path to save and / or export the data list.

9. A computer-readable storage medium storing a computer program, wherein the computer program enables a processor to execute the pilot workload evaluation method based on task complexity analysis according to any one of claims 5 to 8.

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