Shoulder Range of Motion Measurement Using Inertial Measurement Unit-Validation with a Robot Arm

Area of Science:

• Biomechanics
• Sensor Technology
• Human Motion Analysis

Background:

• Inertial Measurement Units (IMUs) provide affordable human motion tracking alternatives to optical systems.
• Sensor accuracy is influenced by calibration methods and data fusion algorithms.
• RSQ Motion sensors are a type of IMU used for motion capture.

Purpose of the Study:

• To evaluate the accuracy of a single RSQ Motion sensor against an industrial robot.
• To assess the impact of different calibration methods on sensor accuracy.
• To determine if angle magnitude and time affect sensor performance.

Main Methods:

• Testing a single RSQ Motion sensor against a precise industrial robot.
• Performing nine repetitions of nine static angles across eleven series.
• Mimicking shoulder movements (flexion, abduction, rotation) with the robot arm.

Main Results:

• The RSQ Motion sensor demonstrated high accuracy with a root-mean-square error under 0.15°.
• A moderate-to-strong correlation was found between sensor error and angle magnitude for gyroscope and accelerometer calibrated sensors.
• Calibration method significantly impacts sensor accuracy.

Conclusions:

• RSQ Motion sensors exhibit high accuracy for motion tracking applications.
• Further research involving human subjects and comparison with gold-standard devices is warranted.
• Calibration techniques are crucial for optimizing IMU performance in biomechanical analysis.