Impact point estimation apparatus

A non-transitory computer readable medium storing an impact point estimation program for estimating an impact point on a face surface of a head when a golf club having a grip, a shaft and the head is swung and hits a golf ball, the program causing a computer to execute the steps of:

• acquiring time series sensor data that is output from at least one of an angular velocity sensor and an acceleration sensor that is attached to at least one of the grip and the shaft;
• calculating a characteristic value of an initial stress wave that occurs due to impact, based on the sensor data acquired in an analysis period including an initial period after impact;
• and
• estimating the impact point on the face surface, according to the characteristic value, wherein the analysis period includes only a period after impact and before 0.005 seconds have elapsed from impact, and
• wherein the characteristic value includes a first characteristic value of an angular velocity about a first axis and a second characteristic value of an angular velocity about a second axis as characteristic values of the initial stress wave that occurs due to impact, and the first and second characteristic values are determined based on the sensor data acquired in the analysis period, the first axis and the second axis being included in a plane that is generally parallel to the face surface and being substantially orthogonal with each other.

An impact point estimation apparatus for estimating an impact point on a face surface of a head when a golf club having a grip, a shaft and the head is swung and hits a golf ball, comprising:

• an acquisition unit configured to acquire time series sensor data that is output from at least one of an angular velocity sensor and an acceleration sensor that is attached to at least one of the grip and the shaft;
• a calculation unit configured to calculate at least one characteristic value of a first wave to a third wave of a stress wave that occurs due to impact, based on the sensor data acquired in an analysis period, the analysis period including only a period after impact and before 0.005 second have elapsed from impact;
• and
• an estimation unit configured to estimate the impact point on the face surface, according to the characteristic value,
• wherein the at least one characteristic value includes a first characteristic value of an angular velocity about a first axis and a second characteristic value of an angular velocity about a second axis as characteristic values of the initial stress wave that occurs due to impact, and the first and second characteristic values are determined based on the sensor data acquired in the analysis period, the first axis and the second axis being included in a plane that is generally parallel to the face surface and being substantially orthogonal with each other.