Measurement method, measurement device, measurement system, and measurement program
A measurement method includes: generating second measurement data by performing filter processing on first measurement data; calculating a first deflection amount based on an approximate equation of deflection of a structure; calculating a second deflection amount by performing filter processing on the first deflection amount; calculating a third deflection amount based on the second deflection amount and a first-order coefficient and a zero-order coefficient which are calculated based on the second measurement data and the second deflection amount; calculating an offset based on the zero-order coefficient, the second deflection amount, and the third deflection amount; calculating a static response by adding the offset and a product of the first-order coefficient and the first deflection amount; calculating a first dynamic response by subtracting the static response from the first measurement data; calculating a second dynamic response by attenuating an unnecessary signal from the first dynamic response; and calculating an attenuation rate of the second dynamic response based on an envelope amplitude of the second dynamic response.
1. A measurement method for causing a processor to execute a process, the method comprising executing on the processor the steps of:
a first measurement data generation step of generating, based on observation data output from a sensor configured to observe an observation point of a superstructure of a bridge, first measurement data based on a physical quantity which is a response to actions of a plurality of parts of a vehicle moving on the superstructure on the observation point;
a second measurement data generation step of generating second measurement data in which a vibration component is reduced by performing filter processing on the first measurement data;
an observation information generation step of generating observation information including an entry time point and an exit time point of the vehicle with respect to the superstructure;
an average velocity calculation step of calculating an average velocity of the vehicle based on the observation information and environment information which is created in advance and includes a dimension of the vehicle and a dimension of the superstructure;
a first deflection amount calculation step of calculating, based on an approximate equation of deflection of the superstructure, the observation information, the environment information, and the average velocity, a first deflection amount of the superstructure caused by the vehicle;
a second deflection amount calculation step of calculating a second deflection amount in which a vibration component is reduced by performing filter processing on the first deflection amount;
a coefficient calculation step of approximating the second measurement data with a linear function of the second deflection amount to calculate a first-order coefficient and a zero-order coefficient of the linear function;
a third deflection amount calculation step of calculating a third deflection amount based on the first-order coefficient, the zero-order coefficient, and the second deflection amount;
an offset calculation step of calculating an offset based on the zero-order coefficient, the second deflection amount, and the third deflection amount;
a static response calculation step of calculating a static response by adding the offset and a product of the first-order coefficient and the first deflection amount;
a first dynamic response calculation step of calculating a first dynamic response by subtracting the static response from the first measurement data;
a second dynamic response calculation step of calculating a second dynamic response by performing filter processing for attenuating an unnecessary signal from the first dynamic response;
an envelope amplitude calculation step of calculating an envelope amplitude of the second dynamic response; and;
an attenuation rate calculation step of calculating, based on the envelope amplitude, an attenuation rate of a vibration component included in the second dynamic response; and
an abnormality detection step of detecting or monitoring an abnormality state of the superstructure of the bridge based on the attenuation rate of the vibration component.
2. The measurement method according to claim 1 , wherein
in the attenuation rate calculation step,
the attenuation rate is calculated by approximating the envelope amplitude by an exponential function in a first interval which is at least a part of an interval in which the vibration component included in the second dynamic response attenuates to calculate a power coefficient of the exponential function, and dividing the power coefficient by a natural frequency of the second dynamic response.
3. The measurement method according to claim 2 , wherein
the exit time point is a time point at which a rearmost part among the plurality of parts of the vehicle passes through an exit end of the superstructure, and
a start time point of the first interval is after the exit time point.
4. The measurement method according to claim 1 , wherein
the filter processing for attenuating an unnecessary signal from the first dynamic response includes low-pass filter processing for attenuating a harmonic component of a vibration component having a fundamental frequency included in the first dynamic response and correcting a gain at the fundamental frequency.
5. The measurement method according to claim 4 , wherein
the filter processing for attenuating an unnecessary signal from the first dynamic response includes high-pass filter processing for attenuating a signal component having a frequency lower than the fundamental frequency.
6. The measurement method according to claim 1 , wherein
in the envelope amplitude calculation step,
the envelope amplitude is calculated by performing low-pass filter processing on an absolute value of the second dynamic response and multiplying the result by TT/2.
7. The measurement method according to claim 1 , wherein
the vehicle includes a railway vehicle, and
each of the plurality of parts is an axle or a wheel.
8. The measurement method according to claim 1 , wherein
the approximate equation of the deflection of the superstructure is an equation based on a structural model of the superstructure.
9. The measurement method according to claim 8 , wherein
the structural model is a simple beam whose both ends are supported.
10. The measurement method according to claim 1 , wherein
the sensor is an acceleration sensor, an impact sensor, a pressure-sensitive sensor, a strain gauge, an image measuring device, a load cell, or a displacement meter.
11. The measurement method according to claim 1 , wherein
the superstructure is a structure in which bridge weigh in motion (BWIM) functions.
12. A measurement device, comprising:
a memory configured to store a program; and
a processor configured to execute the program so as to:
generate, based on observation data output from a sensor configured to observe an observation point of a superstructure, first measurement data based on a physical quantity which is a response to actions of a plurality of parts of a vehicle moving on the superstructure on the observation point;
generate second measurement data in which a vibration component is reduced by performing filter processing on the first measurement data;
generate observation information including an entry time point and an exit time point of the vehicle with respect to the superstructure;
calculate an average velocity of the vehicle based on the observation information and environment information which is created in advance and includes a dimension of the vehicle and a dimension of the superstructure;
calculate, based on an approximate equation of deflection of the superstructure, the observation information, the environment information, and the average velocity, a first deflection amount of the superstructure caused by the vehicle;
calculate a second deflection amount in which a vibration component is reduced by performing filter processing on the first deflection amount;
approximate the second measurement data with a linear function of the second deflection amount to calculate a first-order coefficient and a zero-order coefficient of the linear function;
calculate a third deflection amount based on the first-order coefficient, the zero-order coefficient, and the second deflection amount;
calculate an offset based on the zero-order coefficient, the second deflection amount, and the third deflection amount;
calculate a static response by adding the offset and a product of the first-order coefficient and the first deflection amount;
calculate a first dynamic response by subtracting the static response from the first measurement data;
calculate a second dynamic response by performing filter processing for attenuating an unnecessary signal from the first dynamic response;
calculate an envelope amplitude of the second dynamic response; and
calculate, based on the envelope amplitude, an attenuation rate of a vibration component included in the second dynamic response,
wherein an abnormality state of the superstructure of the bridge is detected or monitored based on the attenuation rate of the vibration component.
13. A measurement system, comprising:
the measurement device according to claim 12 ; and
the sensor.
14. A non-transitory computer-readable storage medium storing a measurement program, the measurement program causing a computer to execute a process by a processor so as to perform the steps of:
generating, based on observation data output from a sensor configured to observe an observation point of a superstructure of a bridge, first measurement data based on a physical quantity which is a response to actions of a plurality of parts of a vehicle moving on the superstructure on the observation point;
generating second measurement data in which a vibration component is reduced by performing filter processing on the first measurement data;
generating observation information including an entry time point and an exit time point of the vehicle with respect to the superstructure;
calculating an average velocity of the vehicle based on the observation information and environment information which is created in advance and includes a dimension of the vehicle and a dimension of the superstructure;
calculating, based on an approximate equation of deflection of the superstructure, the observation information, the environment information, and the average velocity, a first deflection amount of the superstructure caused by the vehicle;
calculating a second deflection amount in which a vibration component is reduced by performing filter processing on the first deflection amount;
approximating the second measurement data with a linear function of the second deflection amount to calculate a first-order coefficient and a zero-order coefficient of the linear function;
calculating a third deflection amount based on the first-order coefficient, the zero-order coefficient, and the second deflection amount;
calculating an offset based on the zero-order coefficient, the second deflection amount, and the third deflection amount;
calculating a static response by adding the offset and a product of the first-order coefficient and the first deflection amount;
calculating a first dynamic response by subtracting the static response from the first measurement data;
calculating a second dynamic response by performing filter processing for attenuating an unnecessary signal from the first dynamic response;
calculating an envelope amplitude of the second dynamic response; and
calculating, based on the envelope amplitude, an attenuation rate of a vibration component included in the second dynamic response,
wherein an abnormality state of the superstructure of the bridge is detected or monitored based on the attenuation rate of the vibration component.