@@ -223,12 +223,12 @@ Further exploration might have included testing the color sensor in different co
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@@ -223,12 +223,12 @@ Further exploration might have included testing the color sensor in different co
### Self balancing robot with gyro sensor
### Self balancing robot with gyro sensor
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After having tried both light and color sensors to get the robot standing we moved on to a gyro sensor. This sensor gives readings of movement and would therefore be ideal for a two wheel balancing robot. These motion readings are ment to be 600 (in raw values) [TODO ref] when completely steady and return smaller or greater numbers depending on the direction of the motion. How much smaller or greater these values are depends on the speed of the motion, as the returned gyro value is measured in angle velocity.
After having tried both light and color sensors to get the robot standing we moved on to a gyro sensor. This sensor gives readings of movement and would therefore be ideal for a two wheel balancing robot. These motion readings are ment to be 600 (in raw values) [6] when completely steady and return smaller or greater numbers depending on the direction of the motion. How much smaller or greater these values are depends on the speed of the motion, as the returned gyro value is measured in angle velocity.
However not all gyro sensors have a stand still value of 600. It might be either greater or lower depending on the specific gyro [TODO ref]. Therefore we started by measuring our specific gyro sensors steady value - called offset.
However not all gyro sensors have a stand still value of 600. It might be either greater or lower depending on the specific gyro [6]. Therefore we started by measuring our specific gyro sensors steady value - called offset.
This was done by placing the robot against a wall, and observing the value over a period of time. The reading varying between 597 and 598, with 598 occuring the most. Our sensor's offset for angular velosity is therefore 598 and not 600 as [TODO ref article writer name] suggests.
This was done by placing the robot against a wall, and observing the value over a period of time. The reading varying between 597 and 598, with 598 occuring the most. Our sensor's offset for angular velosity is therefore 598.
Gyro sensors does not only vary in offset value, they also vary in measured value depending on surronding temperature and given voltage [TODO ref]. This is called the drift of the gyro, as the initial offset value will move when these factors effect the sensor.
Gyro sensors does not only vary in offset value, they also vary in measured value depending on surronding temperature and given voltage [6 and 7]. This is called the drift of the gyro, as the initial offset value will move when these factors effect the sensor.
To test the drift of our sensor, we began by starting ***GyroTest.java*** and letting it run for 10 minutes to check if the sensor developed heat which could then maybe result in a drift of the reading value. This didn't seem to be the case - in the end, the sensor readings were still shifting between 597 and 598.
To test the drift of our sensor, we began by starting ***GyroTest.java*** and letting it run for 10 minutes to check if the sensor developed heat which could then maybe result in a drift of the reading value. This didn't seem to be the case - in the end, the sensor readings were still shifting between 597 and 598.
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@@ -275,6 +275,10 @@ Preliminary experiments with the gyro sensor resulted in a good basis for furthe
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@@ -275,6 +275,10 @@ Preliminary experiments with the gyro sensor resulted in a good basis for furthe
[5] Wikipedia article with information on grid search, [Hyperparameter optimization (grid search)] (https://en.wikipedia.org/wiki/Hyperparameter_optimization#Grid_search)
[5] Wikipedia article with information on grid search, [Hyperparameter optimization (grid search)] (https://en.wikipedia.org/wiki/Hyperparameter_optimization#Grid_search)
[6] [Gyro offset and drift](https://nxttime.wordpress.com/2010/11/03/gyro-offset-and-drift/)
