Systems and methods for determining swimming metrics

A method comprising:

• receiving, by a processor circuit of a wearable device worn on a wrist of a user during a swimming session, motion data from one or more motion sensors of the wearable device;
• determining, by the processor circuit using the motion data, a first set of rotational data of the wearable device, wherein the first set of rotational data is expressed in a first frame of reference;
• converting, by the processor circuit, the first set of rotational data into a second set of rotational data, wherein the second set of rotational data is expressed in a second frame of reference, and wherein the second set of rotational data includes data indicative of the user's arm or wrist movements;
• determining, by the processor circuit, one or more swimming metrics of the user based on the second set of rotational data, where determining the one or more swimming metrics includes:
• detecting a number of turns and a number of strokes of the user during the swimming session based on the received motion data;
• determining a number of strokes per lap based on the number of turns and the number of strokes;
• determining a variance of the number of strokes per lap;
• adjusting the number of turns to reduce the variance of the number of strokes per lap;
• determining a lap count of the user based on the adjusted number of turns;
• and
• outputting, by the processor circuit, the one or more swimming metrics of the user.

A system for improving an accuracy of a wearable device while determining one or more swimming metrics of a user during a swimming session, the system comprising:

• one or more motion sensors configured to collect motion data;
• and
• a processor circuit coupled to the one or more motion sensors and configured to execute instructions causing the processor to:
• determine a first set of rotational data, wherein the first set of rotational data is expressed in a first frame of reference;
• convert the first set of rotational data into a second set of rotational data, wherein the second set of rotational data is expressed in a second frame of reference;
• determine one or more swimming metrics of the user based on the second set of rotational data, where determining the one or more swimming metrics includes:
• detecting a number of turns and a number of strokes of the user during the swimming session based on the received motion data;
• determine a number of strokes per lap based on the number of turns and the number of strokes;
• determine a variance of the number of strokes per lap;
• adjust the number of turns to reduce the variance of the number of strokes per lap;
• determine a lap count of the user based on the adjusted number of turns;
• and
• output the one or more swimming metrics of the user.

A system comprising:

• one or more motion sensors configured to collect motion data, the one or more sensors included in or coupled to a wearable device worn on a wrist of a user during a swimming session;
• a processor circuit coupled to the one or more motion sensors and configured to execute instructions causing the processor to:
• receive motion data from one or more motion sensors of the wearable device;
• determine, using the motion data, a first set of rotational data of the wearable device, wherein the first set of rotational data is expressed in a first frame of reference;
• convert the first set of rotational data into a second set of rotational data, wherein the second set of rotational data is expressed in a second frame of reference, and wherein the second set of rotational data includes data indicative of the user's arm or wrist movements;
• determine one or more swimming metrics of the user based on the second set of rotational data, where the instructed are further executed to:
• detect a number of turns and a number of strokes of the user during the swimming session based on the received motion data;
• determine a number of strokes per lap based on the number of turns and the number of strokes;
• determine a variance of the number of strokes per lap;
• adjust the number of turns to reduce the variance of the number of strokes per lap;
• determine a lap count of the user based on the adjusted number of turns;
• and
• output the one or more swimming metrics of the user.