Measurement system, measurement method, measurement device, and program

1 . A measurement system, comprising:

one or more processors;

one or more storage devices storing one or more programs for execution by the one or more processors;

a first oscillator configured to oscillate a first clock signal having a first clock period;

a second oscillator configured to oscillate a second clock signal having a second clock period longer than the first clock period and with higher period accuracy than the first clock period;

a measurement device executing on at least one of the one or more processors and configured to perform measurement a plurality of times to obtain a plurality of measurement results, the measurement device configured to operate on a first basis of the first clock signal having the first clock period;

a time stamp provision circuit executing on at least one of the one or more processors and configured to provide a time stamp indicating a measurement time to each of two or more of the plurality of measurement results obtained through the measurement device, the time stamp provision circuit configured to provide the time stamp to each of two or more of the plurality of measurement results on a second basis of the second clock signal having the second clock period; and

a measurement time correction circuit executing on at least one of the one or more processors and configured to correct a measurement time of a measurement result other than the measurement result to which the time stamp is provided to obtain a corrected measurement result, the corrected measurement result being among the measurement results obtained during a period specified using two time stamps of the time stamps provided to each of the two or more of the plurality of measurement results.

2 . The measurement system according to claim 1 , wherein:

the plurality of measurement results obtained using the measurement device includes a plurality of measurement result sequences, one measurement result sequence being N measurement results obtained through consecutive N measurements,

the time stamp provision circuit is further configured to add the time stamp to a first measurement result of each of the plurality of measurement result sequences, and

the measurement time correction circuit is further configured to:

specify a measurement period in which the N measurement results of the measurement result sequence are obtained using a difference between the two time stamps;

delete a measurement result from or add a new measurement result to a measurement result sequence in accordance with a length of the specified measurement period; and

bring a first number of measurement results of the measurement result sequence closer to a second number of measurement results obtained in the measurement period when the first clock signal does not have a periodic error to correct the measurement time.

3 . The measurement system according to claim 2 , wherein each of the plurality of measurement results includes a first type of measurement result and a second type of measurement result different from the first type, and the measurement time correction circuit is configured so that the result of the first type of measurement is not deleted when deleting the measurement result.

4 . The measurement system according to claim 2 , wherein the measurement time correction circuit is configured to, when a period of the measurement based on the first clock signal when there is no periodic error is T cycle and the measurement period is T term , delete |M| measurement results from the measurement result sequence when M obtained by the following Expression (A) is negative and add M new measurement results to the measurement result sequence when the M is positive:

M =int( T term /T cycle )− N   ( A )

where, int(T term /T cycle ) is an integer conversion operation of a value obtained through T term /T cycle .

5 . The measurement system according to claim 2 , wherein the measurement result includes a time interval measured on the first basis of the first clock signal, and

the measurement system further includes a measurement result correction circuit executing on at least one of the one or more processors and configured to correct the time interval by multiplying the time interval by a correction coefficient C calculated by the following Expression (B):

C=T term /( T cycle ×N )  ( B )

when T cycle is a cycle of the measurement based on the first clock signal when there is no periodic error, and T term is the measurement period in the measurement system.

6 . A measurement method, comprising:

performing measurement a plurality of times on a first basis of a first clock signal having a first clock period to obtain a plurality of measurement results, wherein the first clock signal having the first clock period is oscillated by a first oscillator;

providing a time stamp indicating a measurement time to each of two or more of the plurality of measurement results obtained through performing the measurement on a second basis of a second clock signal having a second clock period, wherein:

the second clock signal having the second clock period is oscillated by a second oscillator, and

the second clock period is longer than the first clock period and has higher accuracy than the first clock period; and

correcting a measurement time of a measurement result other than the measurement result to which the time stamp is provided among the measurement results obtained during a period specified using two time stamps of the time stamps provided to each of the two or more of the plurality of measurement results.

7 . The measurement method of claim 6 , wherein:

the plurality of measurement results are obtained using a measurement device,

the plurality of measurement results obtained using the measurement device includes a plurality of measurement result sequences, one measurement result sequence being N measurement results obtained through consecutive N measurements, and

the measurement method further comprises:

adding the time stamp to a first measurement result of each of the plurality of measurement result sequences,

specifying a measurement period in which the N measurement results of the measurement result sequence are obtained using a difference between the two time stamps,

deleting a measurement result from or add a new measurement result to a measurement result sequence in accordance with a length of the specified measurement period, and

bringing a first number of measurement results of the measurement result sequence closer to a second number of measurement results obtained in the measurement period when the first clock signal does not have a periodic error to correct the measurement time.

8 . The measurement method of claim 7 , wherein each of the plurality of measurement results includes a first type of measurement result and a second type of measurement result different from the first type, and wherein the result of the first type of measurement is not deleted when deleting the measurement result.

9 . The measurement method of claim 7 , further comprising:

when a period of the measurement based on the first clock signal when there is no periodic error is T cycle and the measurement period is T term , deleting |M| measurement results from the measurement result sequence when M obtained by the following Expression (A) is negative and adding M new measurement results to the measurement result sequence when the M is positive:

M =int( T term /T cycle )− N   ( A )

where, int (T term /T cycle ) is an integer conversion operation of a value obtained through T term /T cycle .

10 . The measurement method of claim 7 , wherein the measurement result includes a time interval measured on the first basis of the first clock signal, and the method further comprises:

correcting the time interval by multiplying the time interval by a correction coefficient C calculated by the following Expression (B):

C=T term /( T cycle ×N )  ( B )

when T cycle is a cycle of the measurement based on the first clock signal when there is no periodic error, and T term is the measurement period in a measurement system.

11 . A non-transitory computer readable storage medium storing a program causing a computer which acquires a plurality of measurement results obtained by performing measurement a plurality of times on a first basis of a first clock signal having a first clock period and a time stamp indicating a measurement time provided to each of two or more of the plurality of measurement results on a second basis of a second clock signal having a second clock period, to function as:

a measurement time correction circuit configured to correct a measurement time of a measurement result other than the measurement result to which the time stamp is provided among the measurement results obtained during a period specified using two time stamps of the time stamps provided to each of the two or more of the plurality of measurement results, in accordance with the period and a number of measurement results obtained during the period among the plurality of measurement results,

wherein:

the first clock signal having the first clock period is oscillated by a first oscillator,

the second clock signal having the second clock period is oscillated by a second oscillator,

the second clock period is longer than the first clock period, and

the second clock period has higher accuracy than the first clock period.