LEDs are gradually being used in underground space lighting due to their advantages of energy saving and environmental protection. Taking subway station space as an example, cities such as Beijing and Shenzhen have already completed the transformation or directly use LED to illuminate the subway station space. At present, Shenzhen Metro Line 2, the Shekou Line, has adopted LED lighting throughout the entire line. It is the first subway line in China that uses LED integrated energy-saving lighting devices.
The application of semiconductor lighting in subway station space has attracted more and more attention: on the one hand, because the glare problem of LED applied to functional lighting seriously affects the safety of lighting; on the other hand, because the underground space is different from the above ground space, the user is An underground space lacking natural light can be anxious, irritating, and undirected. Therefore, as LEDs are gradually applied to subway station space lighting, whether LED can truly replace traditional fluorescent lamps used in subway station space lighting needs to be considered in both theory and practice. In order to promote the application of semiconductor lighting in the subway station space, it is necessary to establish a visual environment evaluation system for the space lighting of the subway station, and subjective evaluation and comprehensive research on the visual environment under the semiconductor lighting.
Therefore, this paper makes use of the established subway station space lighting subway station space visual environment evaluation system, combined with fuzzy comprehensive evaluation method and semantic difference scale method to make each evaluation index into a subjective survey questionnaire, summarizing the results of the questionnaire, the visual environment of the subway station space Prioritize. At the same time, on-site measurement of measurable light environmental indicators, combined with comprehensive evaluation and on-site measurement data, subjective and objective combination to make up the subjectivity and uncertainty of subjective evaluation, making the evaluation results more objective and scientific, and optimal The illuminance and color temperature intervals corresponding to the visual environment of the subway station further guide the space lighting design of the subway station.
Analysis of Research Objects of Space Visual Environment Evaluation in Subway Stations
This paper conducts questionnaire survey and on-site measurement of underground metro stations using LED lighting. At the same time, it also needs to select several typical subway stations with fluorescent lighting to compare and analyze the comprehensive evaluation value and objective measured physical characteristics of the subway station visual environment under the illumination of two kinds of light sources. , thereby obtaining the subway station space with the optimal comprehensive evaluation value and the corresponding objective physical characteristics of the light environment.
In order to measure the objectivity, accuracy and scientificity of the data, to avoid the difference in the attenuation caused by the different use time of the lamps and the subjective feelings of the subjects caused by different regions, climate, culture, etc., this paper selects the direct adoption of the same region at the same time. The Shenzhen Metro Line 2, which is illuminated by LEDs, and the 5 subway stations of Shenzhen Metro Line 2, which are illuminated by fluorescent lights, are being studied.
Shenzhen Metro Line 2
Shenzhen Metro Line 2 is China's first subway line that fully uses LED integrated energy-saving lighting equipment. The station hall and platform public area, entrance and exit channel adopts 300 type LED lighting device, and the platform screen door light belt adopts non-emergency type 200 LED lighting. The device has a single lamp with continuous dimming function, and all LED lighting devices can be dimmed according to mode or operation requirements.
The survey included five underground subway stations, including Grand Theatre Station, Huaqiang North Station, Futian Station, Jingtian Station and Shenkang Station.
According to the investigation, all the subway stations on Shekou Line use LEDs for lighting, making full use of the characteristics of LED dimming. The standard station hall dimming according to the daily flow of people at different times of the day; according to the survey of the staff of the subway station It is known that the subway station hall is in a low-peak mode in most cases. Therefore, subjective investigations and on-site measurements of five subway stations in the Shekou line are carried out in a low-peak mode.
The platform screen door light strip is divided into two types according to whether the train is in the station or not. The illumination and brightness of the train entering the station are close to 2 times when the train is not in the station. Due to the short time of the train entering the station, the user's satisfaction with the light environment of the area mainly comes from the feeling during the waiting period. Therefore, subjective investigation and on-site measurement are carried out when the train is not in the station.
Shenzhen Metro Line 3
The T5 double-tube grille fluorescent lamp is used in the station hall and platform waiting area of ​​Shenzhen Metro Longgang Line (Line 3), and the T5 single-tube grille fluorescent lamp is used for the platform screen door light. The survey included Hongling Station, Tongxinling Station, Huaxin Station, Lianhuacun Station and Children's Palace Station.
The survey found that the station hall and platform style of the same subway station in the Longgang line are unified, most of them are painted with floral patterns, and they all match the name of the station. Different subway stations have different styles, and the unique colors and patterns make it The subway station space has a good artistic effect. For example, the Hongling Station Station Hall and the platform are dominated by red; the Lotus Village Station is decorated with green tones and lotus patterns.
The station halls and platform areas of the Longgang line are illuminated by grille fluorescent lamps. Because the fluorescent lamps can only be distributed in strips, the decoration style is more dull; the lamps are evenly distributed, the illumination uniformity is good, the lighting is soft and comfortable, and there is no obvious glare. problem. In addition to a small number of LED advertising screens in the station hall and platform area, there is no extra advertising banner. Therefore, in addition to the poor brightness of the station space, the brightness uniformity is good, no glare, the overall visual environment is good, and the area is good. Comfort.
Subjective survey of visual environment of subway station space
Metro station visual environment evaluation system
In order to subjectively evaluate the spatial visual environment of the subway station, the author constructs a spatial visual environment evaluation system for the subway station through the analysis and research of relevant theories in the professional field, which mainly includes two parts: evaluation index and index weight:
For the selection of evaluation indicators, the Delphi method is used to evaluate the importance of evaluation factors as evaluation indicators for the purpose of evaluation by means of expert polling. The evaluation indicators suitable for the visual environment evaluation of subway stations are selected by the level of scores. ;
The evaluation weight is calculated by using the analytic hierarchy process to establish the hierarchical structure model and constructing the initial judgment matrix, and the least squares consistency correction model based on the initial judgment matrix is ​​established. The particle swarm optimization algorithm is used to solve the problem. The judgment matrix and the ranking weight vector finally establish a comprehensive evaluation model for the visual environment of the subway station space, as shown in Figure 1. The weights of each index obtained by the particle swarm optimization algorithm are W=[0.09010.07290.10150.11840.06200.08810.02190.07430.10240.01990.01390.01240.04540.05030.07550.0511].
Subjective survey setting
The evaluation of the satisfaction of each indicator in the visual environment is in the form of a semantic difference scale. The semantic difference scale is also called the semantic differentiation scale. This is an attitude measurement technique developed by the American psychologist Osgood after the 1950s. A measure of the measurement of a word or concept understood by the subject at one time. A series of two-way adjective scales are designed for such words or concepts. The subject is asked to select the corresponding position on the scale according to the feelings and understanding of the words or concepts. For example, evaluating the satisfaction level of an environment can be expressed in Table 1.
Table 1 shows 7 levels, the middle level means neutral, neither satisfied nor dissatisfied, the negative sign to the left indicates dissatisfaction, the larger the number, the greater the degree of dissatisfaction; the right positive sign indicates satisfaction, The larger the number, the greater the satisfaction. Regarding the classification of the Semantic Difference Scale Method, according to the research content “Subjective Evaluation and Field Investigation of Visual Illumination Environment of Subway Station Spaceâ€, a 7-level Semantic Difference Scale is defined and a corresponding questionnaire is developed.
Subjective survey results
After the questionnaire is prepared, it is necessary to issue a questionnaire to the selected subway station. Each station will issue 100 questionnaires, 50 stations each and every station. In the course of the questionnaire survey, the passengers participating in the questionnaire survey were explained for the purpose of the survey, and the understanding questions of the questionnaires encountered by the passengers during the survey were detailed. The summary of subjective survey results is shown in Table 2 and Table 3.
Reliability test
Reliability, the consistency and reliability of evaluation, refers to the degree of consistency of results obtained by repeating measurements on the same subject in the same way. Reliability is measured by the reliability coefficient. For the reliability test of the questionnaire, the internal consistency test was performed using the Kronbach alpha coefficient rating scale and the attitude scale. The alpha coefficient evaluates the consistency between the scores in the scale and is an intrinsic consistency coefficient. The value of the alpha coefficient is between 0 and 1. The larger the alpha value, the better the correlation and the higher the internal consistency. Usually, when the reliability alpha value of the test reaches 0.8 or more, it means that the internal consistency is excellent, and it is a test with a relatively high reliability. When the reliability α coefficient value is 0.7 or more, it is a good test and the internal consistency is good. A reliability alpha coefficient value of 0.6 or more is an acceptable reliability.
Using the Spass software for reliability test, it was found that the reliability α coefficient of most subway station spatial visual environment questionnaires reached 0.8 or more, and the internal consistency was good. Only the reliability index value of the Huaxin station platform questionnaire and the Juvenile Palace hall questionnaire was Both 0.641 and 0.765 are acceptable internal consistency, so the results of this survey are acceptable and can be used for follow-up studies.
Visual environment ranking
The average of the obtained questionnaire results is applied to the metro station visual environment evaluation system model, which corresponds to the value of each evaluation index in the model. Then, according to the weights of the evaluation indicators in the model, the weighted summation is obtained. The comprehensive visual scores of the corresponding subway station visual environment are shown in Table 4, and the rankings of the visual environment of the subway station are as follows:
1) LED Station Hall: Futian Station > Shenkang Station > Huaqiang North Station > Grand Theater Station > Jingtian Station;
2) LED platform: Futian Station > Grand Theater Station > Shenkang Station > Jingtian Station > Huaqiang North Station;
3) Fluorescent Light Station Hall: Tongxinling Station>Hongling Station>Juvenile Palace Station>Lianhuacun Station>Huaxin Station;
4) Fluorescent light station: Hongling Station > Children's Palace Station > Lotus Village Station > Tongxinling Station > Huaxin Station.
On-site measurement of space lighting environment indicators for subway stations
After detailed subjective investigations, it is also necessary to conduct on-site measurement of the physical properties of the light environment in five underground subway stations operating in the low-peak mode of LED lighting and five underground subway stations illuminated with fluorescent lamps. Includes measurable values ​​in the light environment: illuminance, color temperature, and more. The purpose of on-site measurement is to analyze whether the light environment parameters in the subway station space meet the national standards. On the basis of meeting the national standards, the combination of subjective investigation and on-site measurement is used to obtain the physical quantity of the light environment corresponding to the comprehensive evaluation value.
Using the CL-200CHROMAMETER color illuminance meter to measure the illumination and color temperature of different stations and stations in the selected 10 subway stations, select 15 measurement points in the measurement area, test 3 sets of data for each measurement point, and summarize the data. Value and analyze. The average illuminance and color temperature of the measured subway station hall and platform area are shown in Table 5.
Corresponding analysis of subjective investigation and on-site measurement of visual environment of subway station space lighting
The comprehensive evaluation of the visual environment includes both subjective and objective aspects, subjective and subjective research, and objective measurement. The subjective questionnaire survey is based on the semantic difference scale method combined with the fuzzy comprehensive evaluation method. Based on the subjective feelings of the people, the overall evaluation of the visual environment is given, and the subjective scores and overall satisfaction of each individual item are given, combined with the individual evaluation indicators. The weight is worthy of the comprehensive evaluation value. Since the overall satisfaction and the score calculated by the model have the same order of merit, the validity of the constructed theoretical model is proved. Through the measurement of the physical parameters of the light environment measurable in the visual environment, illuminance, color temperature, etc., the data has an intuitive and objective understanding of the light environment, and the physical characteristics of the light environment corresponding to the subjective optimal visual environment are obtained.
Illumination level
The average illuminance of different subway station halls and platform areas and the corresponding individual evaluations (illuminance uniformity, visual inducibility), overall satisfaction and comprehensive evaluation values ​​in the subjective survey are shown in Fig. 2 and Fig. 3.
It can be seen from Fig. 2 and Fig. 3 that the average illuminance of the five metro station halls illuminated by LEDs reaches the station hall (underground) illuminance standard value of 200lx specified in GB/T16275-2008 "Urban Rail Transit Lighting", and the fluorescent lamps are used. The average illuminance of the five metro stations in the lighting is mostly lower than the standard 200lx; the illuminance of the platform space meets the illuminance standard value of 150lx. The overall satisfaction and subjective evaluation values ​​are linear with the average illuminance, while the visual inducibility is not directly related to the illuminance, but refers to the guiding effect of the illuminance distribution on the user in the station hall and platform area.
Color temperature analysis
Light color determines the overall atmosphere of the subway station space, and different light colors give people different psychological feelings. From the analysis of Figure 4 and Figure 5:
The color temperature of the LED light source used in the station hall and platform area of ​​the subway line 2, which is illuminated by LED, is mainly concentrated at about 6000K, which is a high color temperature and gives a feeling of coldness. The color temperature of the fluorescent lamps used in the subway station line 3 and the platform area illuminated by fluorescent lamps is concentrated at about 5000K, which is closer to the color temperature of natural light, giving a warm, soft and comfortable feeling.
Because the luminaire shape of Futian Station is different from the panel light in the standard station, it is a non-standard luminaire. The color temperature is lower than that of the standard luminaire. At around 5000K, it is closer to the natural light color temperature, which makes people feel more comfortable in such a visual space. Satisfactory is good.
Summary and outlook
Both subjective and objective: In the five subway stations of Shenzhen Metro Line 2 (Shekou Line) that use semiconductors for illumination, Futian Station Station and Platform Space have the best visual environment; lighting with fluorescent lights Among the five subway stations in Shenzhen Metro Line 3 (Longgang Line), Tongxinling Station Hall and Hongling Station have the best visual environment. The overall satisfaction and comprehensive score of subjective surveys are higher than other stations.
Combining the visual environment satisfaction survey with the physical characteristics of the on-site optical environment, the range of values ​​of the illumination and color temperature of the light environment corresponding to the optimal visual environment is obtained. See Table 6, that is, when the optical environment parameters are in the range shown in Table 6. The visual environment of the subway station space is more comfortable.
In this paper, the spatial visual environment evaluation model of the subway station is used to evaluate the advantages and disadvantages of the space visual environment of the subway station under the two kinds of light sources. The field measurement is used to combine the subjective evaluation based on the model with the objective measurement based on data, and the objective measurement is used. To make up for the defects of subjective evaluation, the combination of subjective and objective research methods can make up for the shortcomings and shortcomings of the two methods to a certain extent, so that the final evaluation results tend to be scientific, objective and reasonable.
At the same time, the overall satisfaction score is consistent with the ranking of the spatial visual environment of the subway station under the comprehensive score, that is, the model is consistent with the survey results, indicating the rationality of the indicators and weights of the constructed model, that is, the theoretical model has universal applicability. The combination of theoretical evaluation and on-site measurement provides a theoretical basis for lighting design and further advances the application of LEDs in large underground spaces, including subway stations.
The application of semiconductor lighting in subway station space has attracted more and more attention: on the one hand, because the glare problem of LED applied to functional lighting seriously affects the safety of lighting; on the other hand, because the underground space is different from the above ground space, the user is An underground space lacking natural light can be anxious, irritating, and undirected. Therefore, as LEDs are gradually applied to subway station space lighting, whether LED can truly replace traditional fluorescent lamps used in subway station space lighting needs to be considered in both theory and practice. In order to promote the application of semiconductor lighting in the subway station space, it is necessary to establish a visual environment evaluation system for the space lighting of the subway station, and subjective evaluation and comprehensive research on the visual environment under the semiconductor lighting.
Therefore, this paper makes use of the established subway station space lighting subway station space visual environment evaluation system, combined with fuzzy comprehensive evaluation method and semantic difference scale method to make each evaluation index into a subjective survey questionnaire, summarizing the results of the questionnaire, the visual environment of the subway station space Prioritize. At the same time, on-site measurement of measurable light environmental indicators, combined with comprehensive evaluation and on-site measurement data, subjective and objective combination to make up the subjectivity and uncertainty of subjective evaluation, making the evaluation results more objective and scientific, and optimal The illuminance and color temperature intervals corresponding to the visual environment of the subway station further guide the space lighting design of the subway station.
Analysis of Research Objects of Space Visual Environment Evaluation in Subway Stations
This paper conducts questionnaire survey and on-site measurement of underground metro stations using LED lighting. At the same time, it also needs to select several typical subway stations with fluorescent lighting to compare and analyze the comprehensive evaluation value and objective measured physical characteristics of the subway station visual environment under the illumination of two kinds of light sources. , thereby obtaining the subway station space with the optimal comprehensive evaluation value and the corresponding objective physical characteristics of the light environment.
In order to measure the objectivity, accuracy and scientificity of the data, to avoid the difference in the attenuation caused by the different use time of the lamps and the subjective feelings of the subjects caused by different regions, climate, culture, etc., this paper selects the direct adoption of the same region at the same time. The Shenzhen Metro Line 2, which is illuminated by LEDs, and the 5 subway stations of Shenzhen Metro Line 2, which are illuminated by fluorescent lights, are being studied.
Shenzhen Metro Line 2
Shenzhen Metro Line 2 is China's first subway line that fully uses LED integrated energy-saving lighting equipment. The station hall and platform public area, entrance and exit channel adopts 300 type LED lighting device, and the platform screen door light belt adopts non-emergency type 200 LED lighting. The device has a single lamp with continuous dimming function, and all LED lighting devices can be dimmed according to mode or operation requirements.
The survey included five underground subway stations, including Grand Theatre Station, Huaqiang North Station, Futian Station, Jingtian Station and Shenkang Station.
According to the investigation, all the subway stations on Shekou Line use LEDs for lighting, making full use of the characteristics of LED dimming. The standard station hall dimming according to the daily flow of people at different times of the day; according to the survey of the staff of the subway station It is known that the subway station hall is in a low-peak mode in most cases. Therefore, subjective investigations and on-site measurements of five subway stations in the Shekou line are carried out in a low-peak mode.
The platform screen door light strip is divided into two types according to whether the train is in the station or not. The illumination and brightness of the train entering the station are close to 2 times when the train is not in the station. Due to the short time of the train entering the station, the user's satisfaction with the light environment of the area mainly comes from the feeling during the waiting period. Therefore, subjective investigation and on-site measurement are carried out when the train is not in the station.
Shenzhen Metro Line 3
The T5 double-tube grille fluorescent lamp is used in the station hall and platform waiting area of ​​Shenzhen Metro Longgang Line (Line 3), and the T5 single-tube grille fluorescent lamp is used for the platform screen door light. The survey included Hongling Station, Tongxinling Station, Huaxin Station, Lianhuacun Station and Children's Palace Station.
The survey found that the station hall and platform style of the same subway station in the Longgang line are unified, most of them are painted with floral patterns, and they all match the name of the station. Different subway stations have different styles, and the unique colors and patterns make it The subway station space has a good artistic effect. For example, the Hongling Station Station Hall and the platform are dominated by red; the Lotus Village Station is decorated with green tones and lotus patterns.
The station halls and platform areas of the Longgang line are illuminated by grille fluorescent lamps. Because the fluorescent lamps can only be distributed in strips, the decoration style is more dull; the lamps are evenly distributed, the illumination uniformity is good, the lighting is soft and comfortable, and there is no obvious glare. problem. In addition to a small number of LED advertising screens in the station hall and platform area, there is no extra advertising banner. Therefore, in addition to the poor brightness of the station space, the brightness uniformity is good, no glare, the overall visual environment is good, and the area is good. Comfort.
Subjective survey of visual environment of subway station space
Metro station visual environment evaluation system
In order to subjectively evaluate the spatial visual environment of the subway station, the author constructs a spatial visual environment evaluation system for the subway station through the analysis and research of relevant theories in the professional field, which mainly includes two parts: evaluation index and index weight:
For the selection of evaluation indicators, the Delphi method is used to evaluate the importance of evaluation factors as evaluation indicators for the purpose of evaluation by means of expert polling. The evaluation indicators suitable for the visual environment evaluation of subway stations are selected by the level of scores. ;
The evaluation weight is calculated by using the analytic hierarchy process to establish the hierarchical structure model and constructing the initial judgment matrix, and the least squares consistency correction model based on the initial judgment matrix is ​​established. The particle swarm optimization algorithm is used to solve the problem. The judgment matrix and the ranking weight vector finally establish a comprehensive evaluation model for the visual environment of the subway station space, as shown in Figure 1. The weights of each index obtained by the particle swarm optimization algorithm are W=[0.09010.07290.10150.11840.06200.08810.02190.07430.10240.01990.01390.01240.04540.05030.07550.0511].
Subjective survey setting
The evaluation of the satisfaction of each indicator in the visual environment is in the form of a semantic difference scale. The semantic difference scale is also called the semantic differentiation scale. This is an attitude measurement technique developed by the American psychologist Osgood after the 1950s. A measure of the measurement of a word or concept understood by the subject at one time. A series of two-way adjective scales are designed for such words or concepts. The subject is asked to select the corresponding position on the scale according to the feelings and understanding of the words or concepts. For example, evaluating the satisfaction level of an environment can be expressed in Table 1.
Table 1 shows 7 levels, the middle level means neutral, neither satisfied nor dissatisfied, the negative sign to the left indicates dissatisfaction, the larger the number, the greater the degree of dissatisfaction; the right positive sign indicates satisfaction, The larger the number, the greater the satisfaction. Regarding the classification of the Semantic Difference Scale Method, according to the research content “Subjective Evaluation and Field Investigation of Visual Illumination Environment of Subway Station Spaceâ€, a 7-level Semantic Difference Scale is defined and a corresponding questionnaire is developed.
Subjective survey results
After the questionnaire is prepared, it is necessary to issue a questionnaire to the selected subway station. Each station will issue 100 questionnaires, 50 stations each and every station. In the course of the questionnaire survey, the passengers participating in the questionnaire survey were explained for the purpose of the survey, and the understanding questions of the questionnaires encountered by the passengers during the survey were detailed. The summary of subjective survey results is shown in Table 2 and Table 3.
Reliability test
Reliability, the consistency and reliability of evaluation, refers to the degree of consistency of results obtained by repeating measurements on the same subject in the same way. Reliability is measured by the reliability coefficient. For the reliability test of the questionnaire, the internal consistency test was performed using the Kronbach alpha coefficient rating scale and the attitude scale. The alpha coefficient evaluates the consistency between the scores in the scale and is an intrinsic consistency coefficient. The value of the alpha coefficient is between 0 and 1. The larger the alpha value, the better the correlation and the higher the internal consistency. Usually, when the reliability alpha value of the test reaches 0.8 or more, it means that the internal consistency is excellent, and it is a test with a relatively high reliability. When the reliability α coefficient value is 0.7 or more, it is a good test and the internal consistency is good. A reliability alpha coefficient value of 0.6 or more is an acceptable reliability.
Using the Spass software for reliability test, it was found that the reliability α coefficient of most subway station spatial visual environment questionnaires reached 0.8 or more, and the internal consistency was good. Only the reliability index value of the Huaxin station platform questionnaire and the Juvenile Palace hall questionnaire was Both 0.641 and 0.765 are acceptable internal consistency, so the results of this survey are acceptable and can be used for follow-up studies.
Visual environment ranking
The average of the obtained questionnaire results is applied to the metro station visual environment evaluation system model, which corresponds to the value of each evaluation index in the model. Then, according to the weights of the evaluation indicators in the model, the weighted summation is obtained. The comprehensive visual scores of the corresponding subway station visual environment are shown in Table 4, and the rankings of the visual environment of the subway station are as follows:
1) LED Station Hall: Futian Station > Shenkang Station > Huaqiang North Station > Grand Theater Station > Jingtian Station;
2) LED platform: Futian Station > Grand Theater Station > Shenkang Station > Jingtian Station > Huaqiang North Station;
3) Fluorescent Light Station Hall: Tongxinling Station>Hongling Station>Juvenile Palace Station>Lianhuacun Station>Huaxin Station;
4) Fluorescent light station: Hongling Station > Children's Palace Station > Lotus Village Station > Tongxinling Station > Huaxin Station.
On-site measurement of space lighting environment indicators for subway stations
After detailed subjective investigations, it is also necessary to conduct on-site measurement of the physical properties of the light environment in five underground subway stations operating in the low-peak mode of LED lighting and five underground subway stations illuminated with fluorescent lamps. Includes measurable values ​​in the light environment: illuminance, color temperature, and more. The purpose of on-site measurement is to analyze whether the light environment parameters in the subway station space meet the national standards. On the basis of meeting the national standards, the combination of subjective investigation and on-site measurement is used to obtain the physical quantity of the light environment corresponding to the comprehensive evaluation value.
Using the CL-200CHROMAMETER color illuminance meter to measure the illumination and color temperature of different stations and stations in the selected 10 subway stations, select 15 measurement points in the measurement area, test 3 sets of data for each measurement point, and summarize the data. Value and analyze. The average illuminance and color temperature of the measured subway station hall and platform area are shown in Table 5.
Corresponding analysis of subjective investigation and on-site measurement of visual environment of subway station space lighting
The comprehensive evaluation of the visual environment includes both subjective and objective aspects, subjective and subjective research, and objective measurement. The subjective questionnaire survey is based on the semantic difference scale method combined with the fuzzy comprehensive evaluation method. Based on the subjective feelings of the people, the overall evaluation of the visual environment is given, and the subjective scores and overall satisfaction of each individual item are given, combined with the individual evaluation indicators. The weight is worthy of the comprehensive evaluation value. Since the overall satisfaction and the score calculated by the model have the same order of merit, the validity of the constructed theoretical model is proved. Through the measurement of the physical parameters of the light environment measurable in the visual environment, illuminance, color temperature, etc., the data has an intuitive and objective understanding of the light environment, and the physical characteristics of the light environment corresponding to the subjective optimal visual environment are obtained.
Illumination level
The average illuminance of different subway station halls and platform areas and the corresponding individual evaluations (illuminance uniformity, visual inducibility), overall satisfaction and comprehensive evaluation values ​​in the subjective survey are shown in Fig. 2 and Fig. 3.
It can be seen from Fig. 2 and Fig. 3 that the average illuminance of the five metro station halls illuminated by LEDs reaches the station hall (underground) illuminance standard value of 200lx specified in GB/T16275-2008 "Urban Rail Transit Lighting", and the fluorescent lamps are used. The average illuminance of the five metro stations in the lighting is mostly lower than the standard 200lx; the illuminance of the platform space meets the illuminance standard value of 150lx. The overall satisfaction and subjective evaluation values ​​are linear with the average illuminance, while the visual inducibility is not directly related to the illuminance, but refers to the guiding effect of the illuminance distribution on the user in the station hall and platform area.
Color temperature analysis
Light color determines the overall atmosphere of the subway station space, and different light colors give people different psychological feelings. From the analysis of Figure 4 and Figure 5:
The color temperature of the LED light source used in the station hall and platform area of ​​the subway line 2, which is illuminated by LED, is mainly concentrated at about 6000K, which is a high color temperature and gives a feeling of coldness. The color temperature of the fluorescent lamps used in the subway station line 3 and the platform area illuminated by fluorescent lamps is concentrated at about 5000K, which is closer to the color temperature of natural light, giving a warm, soft and comfortable feeling.
Because the luminaire shape of Futian Station is different from the panel light in the standard station, it is a non-standard luminaire. The color temperature is lower than that of the standard luminaire. At around 5000K, it is closer to the natural light color temperature, which makes people feel more comfortable in such a visual space. Satisfactory is good.
Summary and outlook
Both subjective and objective: In the five subway stations of Shenzhen Metro Line 2 (Shekou Line) that use semiconductors for illumination, Futian Station Station and Platform Space have the best visual environment; lighting with fluorescent lights Among the five subway stations in Shenzhen Metro Line 3 (Longgang Line), Tongxinling Station Hall and Hongling Station have the best visual environment. The overall satisfaction and comprehensive score of subjective surveys are higher than other stations.
Combining the visual environment satisfaction survey with the physical characteristics of the on-site optical environment, the range of values ​​of the illumination and color temperature of the light environment corresponding to the optimal visual environment is obtained. See Table 6, that is, when the optical environment parameters are in the range shown in Table 6. The visual environment of the subway station space is more comfortable.
In this paper, the spatial visual environment evaluation model of the subway station is used to evaluate the advantages and disadvantages of the space visual environment of the subway station under the two kinds of light sources. The field measurement is used to combine the subjective evaluation based on the model with the objective measurement based on data, and the objective measurement is used. To make up for the defects of subjective evaluation, the combination of subjective and objective research methods can make up for the shortcomings and shortcomings of the two methods to a certain extent, so that the final evaluation results tend to be scientific, objective and reasonable.
At the same time, the overall satisfaction score is consistent with the ranking of the spatial visual environment of the subway station under the comprehensive score, that is, the model is consistent with the survey results, indicating the rationality of the indicators and weights of the constructed model, that is, the theoretical model has universal applicability. The combination of theoretical evaluation and on-site measurement provides a theoretical basis for lighting design and further advances the application of LEDs in large underground spaces, including subway stations.
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