JP2006157463A - Work state recorder, and its recording method, and recording program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a work state recorder capable of automatically recording a work outline as time series information of work actions, and its recording method and recording program. <P>SOLUTION: This work state recorder includes an imaging means (1) to be attached to a human body; a first data collecting means (2) for collecting a video signal outputted from the imaging means (1) as image frame data; and a processing means (3), wherein the processing means (3) calculates a correlation peak value and a correlation peak position between two continuously collected pieces of image frame data in a first period, judges a gazing state in accordance with the correlation peak value and the correlation peak position in the first period and calculates a visual direction stationary time when the gazing state is maintained, and judges a work posture on the basis of information from an acceleration sensor attached to the human body and automatically records work actions by combining the visual direction stationary time and the work posture. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a work situation recording apparatus capable of automatically recording a work situation using information from a small camera and an acceleration sensor attached to an operator, a recording method thereof, and a recording program.

  A field operator's inspection work plays an important role in the normal operation of an oil refinery plant or the like. Skilled operators discover not only the operating status of oil refinery plant equipment but also factors other than equipment such as weather conditions, odors, and sounds in an integrated manner, and such work manuals are used to find signs of abnormalities. Know-how that cannot be expressed is important.

  However, such know-how is based on many years of experience, and inexperienced workers cannot have it, and it takes a long time to acquire that know-how. Accordingly, there is a demand for accumulation and transmission of know-how on maintenance and inspection work.

  In many cases, in order to record maintenance work and maintenance work know-how, the observer must accompany the actual skilled maintenance and inspection work to record the work contents of the worker and record the work contents as a description. In addition, the work is imaged with a video camera and recorded as an image, and the accompanying person records the points.

Patent Document 1 below discloses a field information acquisition and presentation device that records work and facilities using a camera, a position and orientation sensor, and the like used by a worker in maintenance work.
JP 2000-353179 A

  However, in order to extract know-how from video images recorded for maintenance / inspection work as described above, it is necessary to visually check the recorded video images again, and verify them in correspondence with the recorded points. It is necessary to conduct interviews and surveys from experts as appropriate, and there is a problem that takes a long time.

  In addition, a third party is required to record the work, and extra personnel are required, so it is difficult to always record.

In addition, in order to retrieve the record information from the work record recorded by the conventional method by the work posture, the gaze time, or the work content, the manual work record is analyzed again, and the information corresponding to the retrieval item is recorded as the record information. It was necessary to add.
An object of the present invention is to automatically detect a change in the direction in which a worker is looking using video information from a camera and automatically detect a posture during work from body acceleration information in order to solve the above-described problems. It is an object of the present invention to provide a work status recording apparatus, a recording method thereof, and a recording program capable of integrating such information and automatically recording a work summary as time series information of work actions.

  The object of the present invention is achieved by the following means.

That is, the work status recording apparatus according to the present invention includes an imaging unit worn on the body, a first data collection unit that collects a video signal output from the imaging unit as image frame data, and a processing unit. The processing means calculates a correlation peak value and a correlation peak position of two image frame data collected in succession in the first period, and calculates the correlation peak value and the correlation peak position in the first period. Accordingly, the gaze state is determined, the viewing direction stop time during which the gaze state is maintained is obtained, and the gaze degree and the viewing direction stop time corresponding to the gaze state are recorded.

  In the work status recording apparatus, the processing unit obtains a maximum value of the correlation peak value corresponding to a period during which the gaze state is maintained, determines image frame data corresponding to the maximum value, and gazes The image frame data or information for specifying the image frame data can be recorded as image information representative of work contents during the period in which the state is maintained.

  The work status recording apparatus further includes a triaxial acceleration sensor attached to the body, and second data collection means for collecting acceleration vector data output from the triaxial acceleration sensor at a predetermined sampling interval. The processing means calculates an absolute value of each acceleration vector, an average value of these absolute values, and a standard deviation with respect to a predetermined number of the acceleration vector data collected continuously, and calculates the standard deviation and the absolute value. Can determine the posture of the body according to the number of times that exceeds the average value and the sum of the time when the absolute value exceeds the average value, and record the posture index representing the posture of the body.

  Further, in the work status recording apparatus, the processing means calculates an average acceleration vector of the predetermined number of the acceleration vector data, calculates an angle of the average acceleration vector with respect to a gravitational acceleration direction, and calculates the angle as a body inclination. The attitude index can be determined as an angle.

  In the work situation recording apparatus, a work action representing a work situation can be determined according to the gaze degree and the posture index, and information representing the work action can be recorded in association with time information.

  Further, the work status recording method according to the present invention includes a first step of collecting a video signal output from an imaging means attached to the body as image frame data, and 2 continuously acquired in the first period. A second step of calculating a correlation peak value and a correlation peak position of the two image frame data, a third step of determining a gaze state according to the correlation peak value and the correlation peak position in the first period, It includes a fourth step for obtaining a viewing direction stop time in which the gaze state is maintained, and a fifth step for recording a gaze degree corresponding to the gaze state and the viewing direction stop time.

  Further, in the above work status recording method, a sixth step for obtaining a maximum value of the correlation peak value corresponding to a period during which the gaze state is maintained, determining image frame data corresponding to the maximum value, and gaze A seventh step of recording the image frame data or information specifying the image frame data as image information representative of the period during which the state is maintained can be further included.

In the work status recording method, an eighth step of collecting acceleration vector data output from the three-axis acceleration sensor attached to the body at a predetermined sampling interval, and a predetermined number of the continuously collected 9th step of calculating the absolute value of each acceleration vector, the average value of these absolute values, and the standard deviation with respect to the acceleration vector data, the standard deviation, the number of times the absolute value exceeds the average value, and the absolute value And a tenth step of determining the posture of the body according to the sum of the times when the average value exceeds the average value, and recording a posture index representing the posture.

  Further, in the above work status recording method, an eleventh step of calculating an average acceleration vector of the predetermined number of the acceleration vector data, calculating an angle of the average acceleration vector with respect to a gravitational acceleration direction, and calculating the angle as an inclination of the body The angle may include a twelfth step of determining the posture index.

  Further, in the above work status recording method, a thirteenth step of determining a work action representing the work situation according to the gaze degree and the posture index and recording the information representing the work action in correspondence with the time information. Can further be included.

  In addition, the work situation recording program according to the present invention provides a work situation recording apparatus including an imaging unit, a first data collection unit, and a processing unit to be worn on the body, using the first data collection unit. A first function for collecting a video signal output from the imaging means as image frame data; and a first function for calculating a correlation peak value and a correlation peak position of two pieces of the image frame data collected successively in the first period. A third function for determining a gaze state according to the correlation peak value and the correlation peak position in the first period, and a fourth function for obtaining a viewing direction stop time during which the gaze state is maintained, The fifth function of recording the gaze degree corresponding to the gaze state and the viewing direction stop time is realized.

  In the work status recording program, a sixth function for obtaining a maximum value of the correlation peak value corresponding to a period during which the gaze state is maintained in the work status recording device, and an image corresponding to the maximum value. The seventh function of determining the frame data and recording the image frame data or the information specifying the image frame data as the image information representing the period in which the gaze state is maintained can be further realized.

  In the work status recording program, the work status recording apparatus further comprising a triaxial acceleration sensor to be worn on the body and a second data collection unit, the second data collection unit, and the 3 The eighth function of collecting acceleration vector data output from the axial acceleration sensor at a predetermined sampling interval, and the absolute value of each acceleration vector, and the absolute value According to the ninth function for calculating an average value and a standard deviation, the standard deviation, the number of times that the absolute value exceeds the average value, and the total time when the absolute value exceeds the average value, the body And a tenth function for recording a posture index representing the posture can be further realized.

  In the work status recording program, the work status recording apparatus calculates an eleventh function for calculating an average acceleration vector of the predetermined number of the acceleration vector data, and calculates an angle of the average acceleration vector with respect to a gravitational acceleration direction. The twelfth function for determining the posture index can be further realized using the angle as the body inclination angle.

  Further, in the above work status recording program, the work status recording device determines a work action representing the work situation according to the gaze degree and the posture index, and the information representing the work action corresponds to the time information. Thus, the thirteenth function for recording can be further realized.

  According to the present invention, it is possible to automatically detect a change in the direction in which the operator is looking (gaze direction stop information) from video data collected from a camera, and automatically display a representative image during the period of gaze. Can be determined.

Further, the posture information of the worker can be automatically detected from the body acceleration data collected from the acceleration sensor.

  Furthermore, by combining these pieces of information (line-of-sight direction stop information and posture information), it is possible to automatically accumulate work actions representing work outlines in time series.

  In addition, it is possible to automate work record analysis that had to be done manually, and search automatically stored work information as information such as work actions, worker's body posture, worker's gaze time, etc. It becomes possible to do.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the accompanying drawings.

FIG. 1 is a block diagram showing a schematic configuration of a work status recording apparatus according to an embodiment of the present invention. The work status recording apparatus according to the present embodiment includes an imaging unit 1 mounted on a human body, and a first data sampling unit 2 that samples an analog output signal of the imaging unit 1 at a predetermined time interval and outputs the sampled digital video signal. And a three-axis acceleration sensor (hereinafter referred to as an acceleration sensor) 6 to be worn on the human body, and an analog output signal of the acceleration sensor 6 are sampled at predetermined time intervals.
Second data sampling unit 7 that performs D / D conversion and outputs as a digital signal, recording unit 3 that records digital signals from first data sampling unit 2 and second data sampling unit 7, memory unit 4, and each of these units And a processing unit 5 for controlling the above.

  The imaging unit 1 is, for example, a small CCD camera or the like, and is attached to a helmet, and captures an image in the line of sight of a person wearing the helmet. Under the control of the processing unit 5, the first data collection unit 2 collects video signals output from the imaging unit 1 at predetermined sampling intervals and outputs them as digital data (frame unit image data) in the order of collection. . This digital data is recorded in the recording unit 3 in time series.

  On the other hand, the acceleration sensor 6 is attached to, for example, the lower back of a human body and receives external force according to accelerations in three orthogonal directions (X axis, Y axis, Z axis) set in advance in the acceleration sensor 6. Three analog signals are output. Under the control of the processing unit 5, the second data collection unit 7 collects three analog signals output from the acceleration sensor 6 at a predetermined sampling interval Δt and outputs them as digital acceleration data in the order of collection. These digital acceleration data are recorded in the recording unit 3 as time-series vector data.

  In addition to the control of each unit, the processing unit 5 targets image data and acceleration data recorded in the recording unit 3 and performs processing for detecting information related to work conditions, which will be described later, using the memory unit 4 as a work area. To do.

Regarding the attachment to the body, for example, the imaging unit 1 and the first data collection unit 2 are incorporated in the first unit, the acceleration sensor 6 and the second data collection unit 7 are incorporated in the second unit, the recording unit 3, the memory The unit 4 and the processing unit 5 are incorporated in the third unit, and at least the first and second units may be attached to the body. In this case, the data collected by the first and second data collection units may be further provided with communication means (wired or wireless) and transmitted to the recording unit 3 of the third unit.
Hereinafter, functions of the work status recording apparatus according to the present embodiment will be specifically described.

(Visual stop detection function)
Since the video information from the imaging unit 1 attached to the helmet or the like is considered to strongly reflect the video in the direction in which the worker is looking, the blur of the video imaged by the imaging unit 1 attached to the helmet ( By analyzing the amount of motion of the image, it is possible to automatically detect the stopping situation in the visual direction of the worker. This function will be described below.

  FIG. 2 is a flowchart showing a visual direction stop detection function by the work status recording apparatus according to the present embodiment. Here, video data (luminance video) captured by the imaging unit 1 attached to the helmet is recorded in advance in the recording unit 3 as time-series frame data, and the video data is a processing target. In the following description, the processing performed by the processing unit 5 will be described unless otherwise specified. Further, in the processing at each step, the processing unit 5 reads out video data from the recording unit 3 to the memory unit 4 as appropriate, performs calculation using a predetermined area of the memory unit 4 as a work area, and records the result as appropriate. It will be recorded in part 3.

In step S1, initialization is performed. Evaluation time width T ₁ for designating the number of frames to be processed, shift time width ΔT ₁ (ΔT ₁ ≦ T ₁ ), first correlation threshold value H ₁ used in the determination step, second correlation threshold value H ₂ , first movement allowable value D ₁ , and second movement allowable value D ₂ are set. As an example, T ₁ = 2 (seconds), ΔT ₁ = 1 (seconds), H ₁ = 0.2, H ₂ = 0.6, D ₁ = 10, and D ₂ = 18 will be described below. .

In addition, “0” is set to the counter counter k, and “0” is set to all gaze degrees U (i) (i is an integer value of 0 or more). As will be described later, for the time-series image frame data F (k), the head of the processing target image frame data for performing one gaze degree evaluation while shifting by the shift time width ΔT ₁ along the time axis is determined. Therefore, the gaze degree U (i) is provided by the number of times of shifting.

In step S2, two adjacent image frame data F (k) and F (k + 1) are read from the recording unit 3, a normalized correlation value of the two frame data is calculated, and a correlation peak value P (
k) and peak position R (k) = (R _x (k), R _y (k)) are obtained and recorded in the recording unit 3. Here, k corresponds to a time-series frame number, and R _x (k) and R _y (k) are values representing the horizontal and vertical coordinates with the center of the image as the origin in terms of the number of pixels, respectively. .

  The upper part of FIG. 3 shows that a two-dimensional correlation value (correlation pattern) can be obtained from two frame data at times t and t + Δt. The frame correlation value indicates the similarity between two frame images, and indicates a large value when the similarity is high. Here, in order to suppress the influence of the change in the correlation value due to the brightness of the video, the calculation of the frame correlation value is performed after normalizing the brightness of each frame image and then performing the correlation calculation (normalized correlation). Since the method for calculating the normalized correlation value is well known in the field of image processing, detailed description thereof is omitted.

The amount of deviation (R _x (k), R _y (k)) from the center of the peak position of the frame correlation represents the amount of image movement between two frames. Therefore, by calculating the correlation value between frames, the similarity between two frame images and the amount of movement can be evaluated. Therefore, it is possible to obtain the time during which the viewing direction is stopped, that is, the time during which the user is gazing, from the frame correlation value and the movement amount of the correlation peak.

  In step S3, it is determined whether or not frame data to be processed remains. Until it is determined that no frame data remains, the counter k is incremented by 1 in step S4, and then the process returns to step S2.

As described above, the correlation peak value P (k) and peak position R (k) = (R _x (k), R _y (k)) corresponding to the frame data can be obtained. An example is shown in the lower part of FIG. 3 as a correlation value (P (k)), a horizontal movement amount (R _x (k)), and a vertical movement amount (R _y (k)). The horizontal direction in FIG. 3 is the time axis. The correlation value (P (k)) is 0 or more, but the horizontal movement amount (R _x (k)) and the vertical movement amount (R _y (k)) can take negative values.

After resetting the counters k and j to “0” in step S5, the correlation peak value P (k) and peak position R (k) obtained in step S2 recorded in the recording unit 3 in step S6 are Only a predetermined number N ₁ (P (k) to P (k + N ₁ −1), R (k) to R (k + N ₁ −1)) is read. Data number N ₁ for reading is the number of frames per second from the evaluation time width T ₁ as N _f, is calculated by _{N 1 = T 1 · N f} . For example, if T ₁ = 2 (seconds) and N _f = 8 (seconds ⁻¹ ), N ₁ = 16
It becomes.

In step S7, all correlation peak values P (k) to P (k) read in step S6.
It is determined whether the average value P _av (k) of + N ₁ −1) is equal to or greater than the first correlation threshold value H ₁ = 0.2. When it is determined that the first correlation threshold value H ₁ is not equal to or greater than 0.2, the process proceeds to step S8, ΔN ₁ is added to the counter k, the process returns to step S6, and the correlation peak value P to be processed next is obtained. Read a predetermined number N _{1 of} (k) and peak position R (k). Here, ΔN ₁ = N _f · ΔT ₁ . When it is determined that the first correlation threshold value H ₁ = 0.2 or more, the process proceeds to step S9.

In step S9, the gaze degree U (j) is determined under the following conditions and recorded in the recording unit 3. That is, the average value P _av (k) of the correlation peak values, the average values R _av (k) _x and R _av (k) _y of the correlation peak values are in the range of k to k + N ₁ −1.
When P _av (k) ≧ H ₂ , R _av (k) _x ≦ D ₂ , and R _av (k) _y ≦ D ₂ , U (j) = 3,
If H ₁ ≦ P _av (k) <H ₂ , R _av (k) _x ≦ D ₁ , and R _av (k) _y ≦ D ₁ , then U (j) = 2,
When H ₁ ≦ P _av (k) <H ₂ , R _av (k) _x ≦ D ₂ , and R _av (k) _y ≦ D ₂ , U (j) = 1. The value of the counter j is j = k / ΔN ₁ . Here, for example, H ₁ = 0.2, H ₂ = 0
. 6, D ₁ = 10, D ₂ = 18, and U (j) = 3, 2, and 1 represent “gazing strength”, “during gaze”, and “gazing weakness”, respectively. It determined U (j) is the time of the attention degrees of the frame number corresponds to the k + N ₁ -1, and attention degree of the section from k + N ₁ -1 to _{k + N 1 + ΔN 1 -2} . Here, when U (j) is not set, the initially set “0” remains set, and this state is, for example, “other”.

The gaze degree U (j) is a value representing the degree of time (the time during which the user is gazing) that the viewing direction has stopped. The above determination condition is that the stop time in the viewing direction is such that the inter-frame correlation value for all the frames in the evaluation time width T ₁ is larger than the correlation threshold value, and the movement amount of the correlation peak is within the movement allowable range. The stop time is ranked when it is considered to be when.

  In step S10, it is determined whether or not data of the correlation peak value P (k) and peak position R (k) to be processed remains, and steps S6 to S9 are repeated until it is determined that they do not remain. The gaze degree U (j) is thus determined.

  In step S11, the counter j is reset to “0”.

  In step S12, the gaze degree U (j) recorded in the recording unit 3 is read out, and it is determined whether or not it is “0” (“other” state). If it is determined that the value is “0”, the process proceeds to step S14. If it is determined that it is not “0” (a state of gazing), the process proceeds to step S13.

In step S13, a correlation peak value in a section where U (j) other than “0” continues is read from the recording unit 3, a maximum value P (k _max ) is obtained, and a corresponding frame number k _max is determined. And recorded in the recording unit 3. Using the recorded frame number k _max, as will be described later, it is possible to read out image frame data as a representative image of the section. Here, instead of recording the frame number k _max , image frame data as a representative image may be recorded.

  In step S14, it is determined whether or not the gaze degree U (k) to be processed remains. If it is determined that it remains, the process proceeds to step S15 and the counter j is incremented by 1, and then steps S12 to S13 are performed. Repeat the process.

As described above, the frame number k _max for designating a specific frame from the series of frame data is determined.

As an example, the actual measurement data includes T ₁ = 2 (seconds), ΔT ₁ = 1 (seconds), H ₁ = 0.2, H ₂
FIG. 4 and FIG. 5 show the results of applying the series of processes shown in FIG. 2 under the conditions of = 0.6, D ₁ = 10 (pixels), and D ₂ = 18 (pixels). The captured frame image is 320 × 240 pixels. In addition, in order to sharpen the correlation peak, high frequency enhancement processing was performed on each frame image as preprocessing.

  FIG. 4 shows the result of ranking the correlation value, the horizontal movement amount, the vertical movement amount, and the gaze degree in the viewing direction determined from these values, with the horizontal axis as time. The gaze rank is expressed by the height of the bar graph, and the width of the entire continuous bar graph is the stop time.

FIG. 5 shows a frame number k _max corresponding to the maximum value P (k _max ) of the determined correlation peak value with respect to the determination result of FIG. 4, and those images (representative images) are arranged in time order. is there. Numbers (1) to (12) in FIG. 5 correspond to (1) to (12) in FIG. Below each frame image, time information (hour: minute: second) corresponding to the frame number and a stop time (second) in the viewing direction are shown. Many representative images shown in FIG. 5 well explain the progress of the work.

  As described above, the degree of gazing is obtained from the video of the imaging unit 1, and the representative image and the gazing work time (stopping time) are automatically extracted and recorded using the gazing degree.

(Working posture detection function)
FIG. 6 is a flowchart showing a work posture detection function by the work status recording apparatus according to the present embodiment. Here, acceleration data from the triaxial acceleration sensor 6 attached to the waist of the human body is sampled by the second data sampling unit 7 for a predetermined period at a predetermined sampling interval Δt, and recorded in advance as vector data in time series. The acceleration data is the processing target. FIG. 7 shows an example of recorded acceleration data. In FIG. 7, the vertical axis represents the one-axis direction component of the acceleration data, and the horizontal axis represents time.

In step S21, initial setting is performed. Evaluation time width T ₂ , shift time width ΔT ₂ (ΔT ₂ ≦ T ₂ ), sampling interval Δt, upper limit value σ _max and lower limit value σ _{min of} standard deviation σ used in a determination step described later, upper limit value n of the number parameter Predetermined values are set for _max and lower limit value n _min , and time parameter upper limit value t _max and lower limit value t _min . Further, “0” is set in the repeat counter j, and “0” is set in all posture indices V (i) (i is an integer value of 0 or more). As will be described later, the acceleration data to be dealt with once is determined from all the time-series acceleration data while shifting by the shift time width ΔT ₂ along the time axis. (j) is provided.

In step S22, acceleration vectors (g _x (i), g _y (i), g _z (i)) (i = k) between the beginning of the acceleration vector data recorded in time series and the evaluation time width T ₂ ˜k + N ₂ −1), calculate the magnitude of each acceleration vector | g (i) | = (g _x (i) ² + g _y (i) ² + g _z (i) ² ) ^1/2 Their average value g _av and standard deviation σ are calculated. Acceleration data number N ₂ of the evaluation time per width T ₂ are, is calculated by N ₂ = T ₂ / Δt.

In step S23, it is determined whether or not the standard deviation σ calculated in step S22 satisfies σ <σ _min . If it is determined that satisfactory, set to "1" shifts to position indicator V (j) in step S24, after increasing the counter k by .DELTA.N ₂ proceeds to step S25, the flow returns to step S22. If it is determined that the condition is not satisfied, the process proceeds to step S26. Here, increasing the counter k by ΔN ₂ means shifting the shift time width ΔT ₂ along the time axis to determine the head of acceleration data to be processed next, ΔN ₂ = ΔT ₂ / Δt. Therefore, ΔN ₂ ≦ N ₂ .

In step S26, it is determined whether or not the standard deviation σ calculated in step S22 satisfies σ> σ _max . If it is determined that the condition is satisfied, the process proceeds to step S27, where “6” is set in the posture index V (j), and then the process proceeds to step S25. If it is determined that the user is not satisfied, the process proceeds to step S28. The counter j has a relationship of j = k / ΔN ₂ .

In step 28, the number n of times that the magnitude | g (i) | of the acceleration vector obtained in step S22 exceeds the average value g _av and the total time t ₁ where | g (i) |> g _av are calculated. To do.

In step S29, the number n and the total time t ₁ obtained in step S28 are
n _min <n <n _max (Formula 1)
t _min <t ₁ <t _max (Formula 2)
It is determined whether or not the above is satisfied. When it is determined that the relationship of Expression 1 and Expression 2 is satisfied, the process proceeds to Step S30, and “2” is set in the posture index V (j), and then the process proceeds to Step S25. If it is determined that at least one of Expression 1 and Expression 2 is not satisfied, the process proceeds to Step S31.

In step S31, an average vector of acceleration vectors (g _x (i), g _y (i), g _z (i)) (i = k to k + N ₂ −1) in the section is calculated, and the gravitational acceleration direction is calculated. As a reference, the angle θ formed with the calculated average vector is calculated, and the posture index V (j) is set according to the angle θ. Specifically, for example, when 20 (degrees) ≦ θ <36 (degrees), V (j) = 3, and when 36 (degrees) ≦ θ <55 (degrees), V (j) = 4, θ If ≧ 55 (degrees), V (j) = 4 is set. The posture index V (j) set here is applied to the section (k + N ₂ −1 to k + N ₂ + ΔN ₂ −2).

In step S32, it is determined whether or not the acceleration data to be processed remains N ₂ or more, and after returning to step S25 until it is determined that there is no remaining, the processes in steps S22 to S31 are repeated.

By the above process, for each section _{(k + N 2 -1~k + N} 2 + ΔN 2 -2), i.e. every [Delta] T _2, attitude indicator V (j), that is, information indicating the physical condition is determined.

As an example, assuming that the evaluation time width T ₂ = 3 (seconds), the shift time width ΔT ₂ = 1 (second), the average amplitude of the acceleration vector within the evaluation time width T ₂ is g _av , σ _min = 0.2 g _av , σ _max = 0.9 g _av ,
n _min = 0.2 T ₂ / Δt, n _max = 0.8 T ₂ / Δt, t _min = 0.2 T ₂ , t _max = 0.8
Under the condition of T _2, the result of applying the series of processing shown in FIG. 6 to the actually measured acceleration vector, shown in Figure 8. The body acceleration of X, Y, and Z shown in the middle of FIG. 8 indicates data (each component of three axes) collected at a sampling interval Δt = 0.05 (seconds) (20 Hz), and the posture is below that. The result of determination is shown.

The posture determination results indicated by the black bar graphs are “other”, “still”, “walking”, “small slope” when the posture index V (j) is 0, 1, 2, 3, 4, 5, 6 respectively. "," Inclined "," Inclined "," Impact ". Above the body acceleration in FIG. 8 is a comment explaining the work situation by the observer accompanying the worker. Comparing the comment and the posture determination result shows that the posture detection corresponding to the work content is performed well.

(Work status recording function)
Next, a description will be given of a function for estimating a work action at each time using the detection result of the gaze degree and posture of the worker and recording it as information representing the work situation. The estimation of the work activity is the same as the above-mentioned stationary state (high gaze, during gaze, weak gaze, no gaze (other)) of the visual direction of the worker represented by the gaze degree U (j) described above. It is determined in combination with seven types of posture information (stationary, walking, small tilt, middle tilt, large tilt, shock posture change, etc.) of the worker represented by the posture index V (j) described above.

  FIG. 9 is a flowchart showing a work status recording function by the work status recording apparatus according to the present embodiment. Here, the video data and the acceleration data are collected for the same period, the processing shown in FIGS. 2 and 6 is executed, and the same number of gaze degrees U (j) and posture indices V (j) are recorded in the recording unit 3. Suppose that

  In step S41, "0" is set to the counter j. j = 0 corresponds to, for example, the start time of collection of data to be processed (video data and acceleration data).

  In step S42, the gaze degree U (j) and the posture index V (j) are read from the recording unit 3.

In step S43, the parameter W (j) representing the work action is determined according to the combination of the gaze degree U (j) and the posture index V (j) read in step S42, and recorded in correspondence with the value of the counter j. Record in part 3. For example, when discriminating six types of work activities (“movement”, “visual inspection”, “gaze inspection / palpation”, “sagging”, “peeps”, “others”), the following judgment conditions are used. What is necessary is just to determine a work act.
(1) When the posture information is in the “walking (V (j) = 2)” state and the viewing direction stop state is “no stop (U (j) = 0)”, “movement (W (j) = 1) (2) When the posture information is in the “still (V (j) = 1)” state, or the posture information is “walking (V (
j) = 2) ”and when the viewing direction stationary state is“ weak gaze (U (j) = 1) ”, it is determined as“ visual inspection (W (j) = 2) ”(3) posture information is“ In a stationary (V (j) = 1) state and the viewing direction stationary state is “gazing weakness (U (j) = 1)”, “gazing (U (j) = 2)” and “gazing intensity (U (j) = 3) ”, or the posture information is“ walking (V (j) = 1) ”and the viewing direction stationary state is“ gazing (U (j) = 2) ”. And “gaze strength (U (j) = 3)”, it is determined as “gaze inspection / palpation (W (j) = 3)” (4) posture information is “small tilt (V (j)) = 3) "," Inclined (V (j) = 4) "and" Inclined Large (V (j) = 5) "and the visual direction stationary state is" no stationary (U (j ) = 0) "and" Less gaze (U (j) = 1) "," Deflection (W (j) = 4) " Constant (5) posture information is any one of “small inclination (V (j) = 3)”, “inclining (V (j) = 4)” and “large inclination (V (j) = 5)” In addition, when the gaze direction stationary state is any of “Less gaze (U (j) = 1)”, “Long gaze (U (j) = 2)”, and “Long gaze (U (j) = 3)” , “Peep (W (j) = 5)” is determined (6) Other state is determined as “Other (W (j) = 0)” In step S44, it is determined whether or not data to be processed remains. If it is determined that there is data to be processed, the process proceeds to step S45, the counter j is incremented by 1, and the processes in steps S42 to S43 are repeated until there is no more data to be processed.

  As a result, the parameter W (j) representing the work action can be determined. Therefore, if the value of the parameter W (j) (for example, 0 to 5) and the character information representing the work action corresponding to the value are recorded as a table, if the parameter W (j) is determined, By referring to the table, the work action can be displayed as character information or the like.

  As an example, FIG. 10 shows a result of applying the above-described determination conditions (1) to (6) to the stop detection result in the viewing direction shown in FIG. 4 and the work posture detection result shown in FIG. FIG. 10 shows the results for FIGS. 4 and 8 when the time is between 15:37:20 and 15:39:31. In this way, using only the imaging unit 1 and the three-axis acceleration sensor 6 worn by the worker, the work content can be automatically recorded as time series information of the work action.

The case where the past (t−T _{1 to} t) data is used for the evaluation time width T ₁ in order to determine the gaze degree U (j) at a certain time t in the stop detection function in the above-described viewing direction has been described. However, the present invention is not limited to this, and data of an evaluation time width T ₁ (t−T ₁ + τ to t + τ) sandwiching the time t may be used. Here, τ <T ₁ . In order to make a determination at the same evaluation time before and after the evaluation, τ = T _1/2 .

Similarly, regarding the determination of the posture index V (j) in the work posture detection function, data of the evaluation time width T ₂ (t−T ₂ + τ to t + τ) sandwiching the time t may be used. Here, τ <T ₂ . To determine at the same evaluation time back and forth at the time of evaluation, may be set to τ = T _2/2.

In the above-described visual direction stop detection function, work posture detection function, and work status recording function, the case of processing video data and acceleration data recorded in advance in the recording unit has been described. Then, processing may be performed in real time. In that case, for example, the process of step S2 in FIG. 2 showing the stop detection function in the viewing direction is set as a process of collecting a predetermined number of video frame data, and the process of step S22 in FIG. What is necessary is just to process a number of acceleration data. As described above, when data in the range of t−T ₁ + τ to t + τ is used for determining the gaze degree U (j) or the posture index V (j) at a certain time t, Since the data is future data at time t, it is desirable to determine τ (τ <T ₁ ) which is not so large in consideration of processing delay.

Further, regarding the stationary detection function, in step S9, using the average value P _av (k) of the correlation peak values and the average values R _av (k) _x and R _av (k) _y of the peak positions, Although U (j) has been determined, the present invention is not limited to this. For example, depending on whether or not each correlation peak value P (k) and peak positions R (k) _x and R (k) _{y in} the section of k to k + N ₁ −1 satisfy the above-described condition, U (j) may be determined.

In addition, the first and second correlation threshold values H ₁ and H ₂ , the first and second movement allowable values D ₁ and D ₂ , the lower limit value and the upper limit value σ _min , σ of the standard deviation shown as an example above. _max, lower limit and upper limit n _min of times, n _max, the lower limit and the upper limit value t _min of the time parameter, the value of such t _max is not limited to the above values can be set as appropriate.

  Moreover, although the case where the gaze degree is classified into three ranks, the posture state is classified into seven types, the tilted state is classified into three ranks, and the work actions are classified into six types is described above, the present invention is not limited to these. Can be classified as few as possible.

  For example, when the degree of gaze is one rank, the correlation peak value is 0.2 or more, and the allowable movement amount is within 18 pixels, it may be determined that the gaze state (the viewing direction is stopped).

Further, although the movement allowable amount is set to the same value in the horizontal direction and the vertical direction, it may be a different value. The distance from the center of the frame image ((R _x ) ² + (R _y ) ² ) ^1/2 The movement allowance may be specified with.

It is a block diagram which shows schematic structure of the working condition recording apparatus which concerns on embodiment of this invention. It is a flowchart which shows the stop information detection function of a visual direction by the working condition recording device which concerns on embodiment of this invention. It is a figure explaining calculation of a frame correlation value. It is a figure which shows an example of the result of having applied the stop information detection function of the viewing direction by the working condition recording device which concerns on embodiment of this invention. It is a figure which shows the extraction result of the representative image during the stop time shown in FIG. It is a figure which shows an example of the result of having performed the detection process function of the walking state by this body state detection apparatus. It is a figure which shows an example of acceleration data. It is a figure which shows an example of the result of having performed the working posture detection function by the working condition recording device which concerns on embodiment of this invention. It is a flowchart which shows the work condition recording function by the work condition recording apparatus which concerns on embodiment of this invention. It is a figure which shows an example of the result of having performed the work condition recording function by the work condition recording device which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Imaging part 2 1st data collection part 3 Recording part 4 Memory part 5 Processing part 6 Acceleration sensor 7 2nd data collection part

Claims (15)

Imaging means attached to the body;
First data collection means for collecting a video signal output from the imaging means as image frame data;
Processing means,
The processing means is
In the first period, the correlation peak value and the correlation peak position of two image frame data collected in succession are calculated,
According to the correlation peak value and the correlation peak position in the first period, determine a gaze state,
Obtaining a viewing direction stop time in which the gaze state is maintained;
An operation status recording apparatus that records a gaze degree corresponding to the gaze state and the viewing direction stop time. The processing unit is
Find the maximum value of the correlation peak value corresponding to the period during which the gaze state is maintained,
Determining image frame data corresponding to the maximum value;
2. The work status recording apparatus according to claim 1, wherein the image frame data or information for specifying the image frame data is recorded as image information representative of work contents during a period in which the gaze state is maintained. A triaxial acceleration sensor worn on the body;
A second data sampling means for sampling acceleration vector data output from the three-axis acceleration sensor at a predetermined sampling interval;
The processing means is
Calculate the absolute value of each acceleration vector, the average value of these absolute values, and the standard deviation for a predetermined number of the acceleration vector data collected continuously,
The body posture is determined according to the standard deviation, the number of times the absolute value exceeds the average value, and the total time the absolute value exceeds the average value,
The work status recording apparatus according to claim 1, wherein a posture index representing the posture of the body is recorded. The processing means is
Calculating an average acceleration vector of the predetermined number of the acceleration vector data;
Calculate the angle of the average acceleration vector relative to the gravitational acceleration direction,
The work status recording apparatus according to claim 3, wherein the posture index is determined using the angle as a body inclination angle. In accordance with the gaze degree and the posture index, a work action representing a work situation is determined,
The work status recording apparatus according to claim 4, wherein information representing the work action is recorded in association with time information. A first step of collecting a video signal output from an imaging means attached to the body as image frame data;
A second step of calculating a correlation peak value and a correlation peak position of two image frame data collected in succession in a first period;
A third step of determining a gaze state according to the correlation peak value and the correlation peak position in the first period;
A fourth step for obtaining a viewing direction stop time in which the gaze state is maintained;
And a fifth step of recording a gaze degree corresponding to the gaze state and the viewing direction stop time. A sixth step of obtaining a maximum value of the correlation peak value corresponding to a period during which the gaze state is maintained;
A seventh step of determining image frame data corresponding to the maximum value and recording the image frame data or information specifying the image frame data as image information representative of a period during which the gaze state is maintained; The work status recording method according to claim 6, further comprising: An eighth step of collecting acceleration vector data output from the three-axis acceleration sensor worn on the body at a predetermined sampling interval;
A ninth step of calculating an absolute value of each acceleration vector, an average value of these absolute values, and a standard deviation with respect to a predetermined number of the acceleration vector data continuously collected;
The posture of the body is determined according to the standard deviation, the number of times the absolute value exceeds the average value, and the total time for which the absolute value exceeds the average value, and a posture index representing the posture is recorded. The work status recording method according to claim 6, further comprising: a tenth step. An eleventh step of calculating an average acceleration vector of the predetermined number of the acceleration vector data;
9. The work status recording method according to claim 8, further comprising a twelfth step of calculating an angle of the average acceleration vector with respect to a gravitational acceleration direction, and determining the posture index using the angle as a body inclination angle. .   The method further comprises a thirteenth step of determining a work action representing a work situation according to the gaze degree and the posture index, and recording information representing the work action in association with time information. 9. The work status recording method according to 9. In a work status recording device comprising an imaging means attached to the body, a first data collection means, and a processing means,
A first function of collecting a video signal output from the imaging unit as image frame data using the first data sampling unit;
A second function for calculating a correlation peak value and a correlation peak position of two image frame data collected in succession in the first period;
A third function for determining a gaze state according to the correlation peak value and the correlation peak position in the first period;
A fourth function for obtaining a viewing direction stop time in which the gaze state is maintained;
A work status recording program that realizes a fifth function that records a gaze degree corresponding to the gaze state and the viewing direction stop time. In the work status recording device,
A sixth function for obtaining a maximum value of the correlation peak value corresponding to a period during which the gaze state is maintained;
A seventh function of determining image frame data corresponding to the maximum value and recording the image frame data or information specifying the image frame data as image information representative of a period during which the gaze state is maintained; The work status recording program according to claim 11, which is realized. In the work status recording apparatus further comprising a triaxial acceleration sensor worn on the body and a second data collection means,
An eighth function for collecting acceleration vector data output from the three-axis acceleration sensor at a predetermined sampling interval using the second data collection means;
A ninth function for calculating an absolute value of each acceleration vector, an average value of these absolute values, and a standard deviation with respect to a predetermined number of the acceleration vector data continuously collected;
The posture of the body is determined according to the standard deviation, the number of times the absolute value exceeds the average value, and the total time for which the absolute value exceeds the average value, and a posture index representing the posture is recorded. The work status recording program according to claim 11 or 12, further comprising realizing the tenth function. In the work status recording device,
An eleventh function for calculating an average acceleration vector of the predetermined number of the acceleration vector data;
The work situation according to claim 13, further comprising: a twelfth function that calculates an angle of the average acceleration vector with respect to a gravitational acceleration direction and determines the posture index by using the angle as a body inclination angle. Recording program. In the work status recording device,
The thirteenth function of determining a work action representing a work situation according to the gaze degree and the posture index and recording information representing the work action in association with time information is further realized. 14. A work status recording program according to 14.

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