Page 119 - Toucpad robotics C11

Working Principle
MEMS gyroscopes typically use tiny vibrating structures. When the sensor is rotated, the Coriolis effect (a force that
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acts on a moving object within a rotating frame of reference) causes these vibrating structures to deflect.
The sensor detects this deflection, which is proportional to the angular velocity.
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It measures rotation around three perpendicular axes: roll (rotation around the front-back axis), pitch (rotation
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around the side-to-side axis), and yaw (rotation around the vertical axis).
Applications in Robotics

Orientation and Balance Control: Crucial for maintaining the balance of bipedal (two-legged) robots and self-
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balancing robots (like Segways).
Drone Stabilisation: Essential for keeping drones stable in the air and controlling their rotational movements.
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Robotic Arm Stability: Helping robot arms maintain a desired orientation during complex movements.
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Navigation Systems: Used in conjunction with accelerometers for inertial navigation (dead reckoning) when Global
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Positioning System (GPS) signals are unavailable or inaccurate.
Advantages
Directly Measures Rotational Motion: Provides precise data on how fast a robot is turning.
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High Sensitivity: Can detect even subtle rotations.
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Compact and Lightweight (MEMS): Modern gyroscopes are very small and can be easily integrated.
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Disadvantages
Drift Over Time: Due to integration of angular velocity, errors can accumulate, causing the estimated orientation to
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“drift” over long periods, requiring periodic recalibration or fusion with other sensors.
Sensitive to Vibration: Can be affected by vibrations or sudden jolts, leading to noisy readings.
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Accelerometers
Description

An Accelerometer is a sensor that measures proper acceleration, which is the acceleration it experiences relative
to freefall. It can detect both static acceleration (like the force of gravity) and dynamic acceleration (due to motion
or vibration).

Working Principle
MEMS accelerometers typically consist of a tiny seismic mass (a spring-like structure) that is free to move.
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When the sensor experiences acceleration, the seismic mass deflects.
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This deflection causes a change in capacitance or resistance, which is then measured and converted into an electrical
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signal proportional to the acceleration.
They usually measure acceleration along three perpendicular axes (x, y, and z).
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Applications in Robotics
Tilt and Orientation Detection: By measuring the direction of gravity’s pull, an accelerometer can determine the
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robot’s tilt or inclination relative to the ground.
Vibration Monitoring: Detecting vibrations in robot components to identify potential issues.
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Impact Detection: Sensing sudden impacts or collisions.
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Basic Motion Detection: Determining if a robot is moving or stationary.
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Humanoid Robot Gait Analysis: Understanding forces during walking.
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Advantages

Detects Gravity: Useful for determining orientation relative to the Earth’s surface.
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Electrical and Control Systems